Implications for Hydrogeology in the Upper Cretaceous Dunvegan Formation

Evolution of Stratigraphic Models in a Fluvial Deltaic Wedge: Implications for Hydrogeology in the Upper Cretaceous Dunvegan Formation

Nathan Glas

A Thesis presented to The University of Guelph

In partial fulfilment of requirements for the degree of Master of Applied Science in Engineering

Guelph, Ontario, Canada

ABSTRACT

EVOLUTION OF STRATIGRAPHIC MODELS IN A FLUVIAL DELTAIC WEDGE: IMPLICATIONS FOR HYDROGEOLOGY IN THE UPPER CRETACEOUS DUNVEGAN FORMATION

Nathan Glas Advisor: University of Guelph, 2021 Professor Beth Parker

This study investigates the Dunvegan Formation, an important aquifer system within the Liard

Basin and Western Canada Sedimentary Basin (WCSB). Concerns surrounding contamination of fresh groundwater resources within the Northwest Territories (NWT) arose due to potential unconventional oil and gas development within their borders and adjacent past and active development. These concerns resulted in a comprehensive baseline study to characterize groundwater quality and quantity within the NWT portion of the Liard Basin near the Hamlet of

Fort Liard, currently reliant on groundwater. This study utilizes historic and newly collected data from surface geophysics, outcrop descriptions and rock core drilling to update the conceptual model for the Dunvegan Formation across the WCSB and within the Liard Basin, and better document aquifer and aquitard properties. The proposed sequence stratigraphic conceptual model of the Dunvegan Formation provides a 3D framework for future groundwater characterization and monitoring system installations in the Liard Basin.

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ACKNOWLEDGEMENTS I would like to thank my supervisor Dr. Beth Parker for her continued support throughout this degree and for providing me the opportunity to work on this project. Her passion for field-focused research and her expertise in fractured bedrock hydrogeology have greatly contributed to this project and helped make it a meaningful and highly educational experience. I would also like to thank my advisory committee members Dr. Colby Steelman for his valuable perspective and insight throughout this degree, and Dr. Janok Bhattacharya for agreeing to contribute his time and knowledge to this endeavour. This research project was funded in part through a Northwest Territories (NWT) Environmental Studies Research Fund (ESRF) grant and through the Government of the Northwest Territories (GNWT) Transboundary Waters Program. This project involved collaboration with many partners, including the GNWT, the Hamlet of Fort Liard, Liard River Consulting, the Acho Dene Koe (ADK) First Nation, ADK Corporation and their subsidiary, Beaver Enterprises. I would like to extend my gratitude to Isabelle de Grandpre, Anna Coles, Casey Beel and Christopher Cunada of the GNWT; Al Harris of the Hamlet of Fort Liard; Irvin Perreault of Liard River Contracting; Sylvia Bertrand of ADK Corporation; and Barney Dohm, Tom Wezelman, Warren Cumberland and Pete Fantasque of Beaver Enterprises for their time, expertise and continued assistance throughout this work. The success of this project is owed in large part to the G360 team that participated in this research. I am incredibly grateful for the expertise and assistance of my Project Manager, Amanda Pierce, and the rest of the field team Dr. Jonathan Munn, Oliver Conway-White and Marina Nunes for various aspects of project management and data collection related to this project. Additionally, many members of the G360 Office of the Director, field and lab staff deserve my gratitude for their contributions including Jen Hurley, Luis Rios, Tarju Dweh-Chenneh, Vinu Raj Vijayakumaran, Ryan Kroeker, Maria Gorecka and Wayne Noble. Thank you for your efforts. Furthermore, thanks are owed to the various laboratories and scientists that provided inkind support and/or research rates for work completed, some of which is included within this document and some of which forms the basis for future work. This includes Kim Janzen of the McDonnell Hillslope Hydrology Lab (University of Saskatchewan), Dr. Frank Barone of Golder Associates Ltd., Michael Nightingale and Dr. Bernhard Mayer of the Applied Geoscience Group (University of Calgary), Dr. Ian Clark of the Advanced Research Complex (University of Ottawa), Dr. William Matthews of the Geo- and Thermochronology Lab (University of Calgary) and Martin Ouellette of the Petrographic Thin-Section Laboratory (Brock University). I am also incredibly grateful for the community of family and friends who have supported me throughout this endeavor. Whether in Canada, the US, or elsewhere, you’ve kept me motivated, grounded and engaged. Thank you for sticking by me and providing much-needed distractions. Fellow G360 students, current and alumni, whether through volleyball, trivia, potlucks, ski trips or nights out, you made grad student life enjoyable and I look forward to running into you down the

iv road. Thank you for sharing your knowledge, time, and the not-so-occasional beer. Cheers to long and fruitful careers in the world of water and rocks. I especially would like to acknowledge my parents, Marnie Wortzman and Tom Glas; sisters, Abby and Tori Glas; and girlfriend, Molly Mackenzie. Without your love and support I would not have made it here. Finally, this research was prompted by and completed in partnership with local First Nations and Métis people. I would like to acknowledge the Dehcho First Nation, Acho Dene Koe First Nation, and Liard First Nation on whose traditional territory this research was conducted, with much respect for their enduring knowledge and wisdom.

TABLE OF CONTENTS

Abstract ...... ii Acknowledgements ...... iii Table of Contents ...... v List of Tables ...... vii List of Figures ...... viii List of Abbreviations ...... ix 1.0 Introduction ...... 1 1.1 Background ...... 1 1.2 Motivation ...... 2 1.3 Study Objectives ...... 4 2.0 Approach and Methods ...... 5 2.1 Site Description ...... 5 2.2 Study Approach ...... 6 2.3 Methods...... 7 2.3.1 Bedrock Characterization ...... 7 2.3.2 Core Logging and Sampling ...... 8 2.3.3 Downhole Natural Gamma Logging ...... 8 2.3.4 Sequence Stratigraphic Analysis...... 8 2.3.5 Physical Property Analysis ...... 8 2.3.6 Porewater Hydrochemistry ...... 9 2.3.7 Surface Electrical Resistivity Surveys ...... 9 3.0 Results & Discussion ...... 10 3.1 Stratigraphic Architecture of the Dunvegan Formation ...... 10 3.1.1 Upper Dunvegan Formation ...... 10 3.1.2 Lower Dunvegan Formation ...... 12 3.1.3 Lithostratigraphic Model of the Dunvegan Formation ...... 13 3.1.4 Sequence Stratigraphic Model of the Dunvegan Formation ...... 14 3.1.5 The Dunvegan Formation within the Western Canada Sedimentary Basin ...... 16 3.2 Hydrogeology of the Dunvegan Formation within the Liard Basin ...... 18 3.2.1 Hydrogeologic Implications of the Sequence Stratigraphic Conceptual Model ...... 18

3.2.2 Spatial Extent of the Dunvegan Formation near Fort Liard ...... 19 3.2.3 Regional Structural Features ...... 22 3.2.4 Aquitard Boundaries and Integrity...... 24 3.2.5 Fracture Network ...... 24 3.2.6 Physical and Hydraulic Properties of the Dunvegan Formation ...... 25 3.2.7 Porewater Hydrochemistry ...... 26 3.3 Proposed Monitoring Well Network ...... 27 4.0 Conclusions ...... 28 References ...... 31 Appendix A: Additional Background Literature Review ...... 57 Appendix B: Lab Method and Lab Results for Non-Reported Samples ...... 103 Appendix C: Inorganic Anion and Cation Analysis (SOP) ...... 121 Appendix D: NWT01 Strat Log ...... 124 Appendix E: Data Tables from Paleodepth Calculations ...... 125 Appendix F: Text Descriptions of Dunvegan Formation from Historical Data ...... 127 Appendix G: Stratigraphic Logs Created ...... 143 Appendix H: Data Tables from Stratigraphic Logs ...... 167 Appendix I: Complete ERT Results ...... 174 Appendix J: 2022 Field Plan and Details ...... 193 Appendix K: A-DTS Results ...... 205

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LIST OF TABLES

Table 1: Summary of channel geometry and variability within the Dunvegan Formation ...... 39 Table 2: ERT survey details...... 40 Table 3: Summary of physical property samples from the Dunvegan Formation at NWT01...... 41

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LIST OF FIGURES

Figure 1: Basin scale schematic ...... 42 Figure 2: Basins of relevance - Dunvegan Formation ...... 43 Figure 3: Paleogeographic map of North America (Cenomanian Age) ...... 44 Figure 4: Liard Basin lithostratigraphic cross section ...... 45 Figure 5: Fort Liard region map...... 46 Figure 6: NWT01 borehole datasets ...... 47 Figure 7: Stratigraphic features in NWT01 core ...... 48 Figure 8: Stratigraphic logs created from Stott’s outcrop descriptions ...... 49 Figure 9: Conceptual models of the Dunvegan Formation within the Liard Basin ...... 50 Figure 10: N-S Dunvegan Formation profile ...... 51 Figure 11: 3D conceptual model of the upper and lower Dunvegan Formation within the Fort Liard Region...... 52 Figure 12: NWT01 stratigraphic log and gamma log overlaid on Site R1 ERT section...... 53 Figure 13: Processed ERT dipole-dipole survey sections...... 54 Figure 14: Major ion results ...... 55 Figure 15: Schematic of paired boreholes ...... 56

LIST OF ABBREVIATIONS

2D Two dimensional 3D Three dimensional AB Alberta A-DTS Active, Distributed Temperature Sensor BC British Columbia cm Centimetre cps Counts per second CSM Conceptual Site Model CWIS Cretaceous Western Interior Seaway DFN-M Discrete Fracture Network-Matrix DTS Distributed Temperature Sensor ERT Electrical resistivity tomography FSM Fish scale member FSU Fish scales upper GNWT Government of the Northwest Territories HDPE High-density polyethylene HGU Hydrogeologic unit IC Ion chromatography K Hydraulic conductivity km Kilometre m Metre Ma Million years ago mbgs Metres below ground surface MLS Multi-level system MVLWB Mackenzie Valley Land and Water Board NWT Northwest Territories O&G Oil & Gas OROGO Office of the Regulator of Oil and Gas Operations RMSE Root mean squared error RQD Rock Quality Designation TOC Total organic carbon V Volt WCSB Western Canada Sedimentary Basin YT Yukon Territory

1.0 Introduction 1.1 Background The Hamlet of Fort Liard (population ~500) lies in the southwest corner of the Northwest Territories (NWT) within a region deemed the “Tropics of the North”, situated in a micro-climate with discontinuous permafrost (VanGulck, 2016). Fort Liard lies within the Liard Basin and Liard River Watershed, the latter being a sub-basin within the Mackenzie River Basin that covers ~20% of Canada (~1,800,000 km2) (VanGulck, 2016). This comparably warm micro-climate (average annual temperature of -1°C) is likely to be exacerbated by the fact that the Mackenzie River Basin is forecast to experience the greatest rate of warming of anywhere on the planet due to climate change (NWT Water Stewardship Strategy, 2018). This change is likely to have drastic effects on the predictability of the Liard River’s seasonal flow and its associated groundwater-surface water interactions, which the Hamlet of Fort Liard rely on for food, transport, and their water supply through groundwater pumping. Eighty-two percent of Canadas’s rural and remote population relies on groundwater for their drinking source (Novakowski, 2015). The Hamlet of Fort Liard represents the largest domestic user of groundwater in the NWT; other communities include Whati (population 470) and Nahanni Butte (population 87). Groundwater is out of sight and rarely monitored, hence it is a resource that is poorly understood throughout Canada, especially in remote areas such as the NWT. The fresh groundwater zone varies in thickness based on subsurface strata permeability, water availability and past geologic and hydrologic conditions (i.e. ice ages, recharge rates, rates of extraction or exploitation). Within this zone, meteoric water recharges and circulates through multiple aquifer and aquitard layers (Toth, 2009). Underlying the freshwater zone, groundwater is generally older and more brackish-saline. The global volume and distribution of this zone of modern, meteoric, fresh groundwater is poorly characterized as the groundwater system is rarely fully instrumented or studied (Gleeson et al., 2015). Oil and gas (O&G) development can impact shallow groundwater and surface water quality through migration of stray gases, deep formation waters, and industrial chemicals associated with fracking and unconventional gas development (Jackson et al., 2013). The Liard Basin is an important freshwater basin located in the headwaters of the Mackenzie River Basin, which is the second largest drainage basin in North America after the Mississippi. The Liard Basin is not only an important freshwater resource but is estimated to be the second largest unconventional oil and gas basin in Canada and ninth in the world, crossing the borders of NWT, Yukon (YT) and British Columbia (BC) (Walsh, 2004; NEB et al., 2016). The Liard Basin is positioned within the larger Western Canada Sedimentary Basin, Canada’s most prolific O&G region (NEB et al., 2016). The proximity of the Hamlet of Fort Liard to ongoing unconventional development in BC (Walsh, 2004), has raised concerns about contamination of freshwater resources. Concerns have been similarly raised due to potential unconventional development within Northwest Territories borders. Given the potential impacts of climate change and unconventional O&G development across the Liard Basin, a robust 3D monitoring approach for the groundwater flow system is needed that monitors the variability of hydrochemical and hydraulic characteristics in space, including depth, and time, to establish current baseline water quality conditions and susceptibility to changes over time to understand and manage local water resources.

The Canadian Government has recently announced plans to create a Canadian Water Agency tasked with unifying water governance and promoting sustainable uses of Canada’s freshwater resources (Canada Water Agency, 2020). This national water agency builds upon existing governance frameworks, such as the Mackenzie River Basin Transboundary Water Master Agreement (the Master Agreement), signed by the Governments of Saskatchewan, Alberta (AB), British Columbia, Yukon, Northwest Territories and Canada in 1997, to coordinate the management of shared water and aquatic ecosystems (VanGulck, 2016). With support from local communities and First Nations, bilateral agreements were signed between the Government of the NWT (GNWT) and YT (2002), BC (2015), and AB (2015) to support and build upon the Master Agreement. A NWT water stewardship strategy has also been created to ensure NWT waters remain clean, abundant and productive, with productivity defined as waters that are able to sustain both ecosystem life and human activities (NWT Water Stewardship Strategy, 2018). This strategy recognizes that effects of climate change, as well as economic growth and development, can have harmful consequences for water resources, ecosystems and residents. It also recognizes and promotes the Aboriginal ideal that freshwater is fundamental to life, and that clean, abundant freshwater systems ensure healthy and productive ecosystems. Further, preserving these freshwater systems helps to retain the social, cultural and economic well-being of NWT residents and future generations. However, effective management requires system understanding, such as recharge rates, groundwater residence times and natural geochemical variability, which is the basis for developing a robust baseline groundwater monitoring network. The waters of the NWT have many uses, from agriculture, oil and gas, mining, forestry and power generation to water supply, fishing and transport. The latter three have allowed the Aboriginal people of NWT, who make up ~50% of the population, to sustain themselves for thousands of years (NWT Water Stewardship Strategy, 2018). This Strategy (2018) states that all lands are watersheds and that activity on all lands influence the waters that flow through them, making it important to preserve lakes, rivers, deltas, wetlands and the surface and groundwater that supply them, which are all inextricably linked. It is noteworthy that this strategy recognizes the importance of economic development to Canada’s Aboriginal and Northern communities and promotes initiatives for environmentally responsible development based on “comprehensive, community-based, ecosystem-focused, water quality monitoring programs.” It is this principle that motivates this study, to develop a state of the science groundwater flow system monitoring program for remote northern communities like Fort Liard. 1.2 Motivation Rapid growth in the development of unconventional oil and gas (i.e., shale gas) resources over recent decades (BCOGC, 2019), has driven a push to better assess potential environmental impacts associated with resource extraction in Canada (CCA, 2014) and globally (Cook et al., 2013; UK Economic Affairs Committee, 2014; German Advisory Council on the Environment, 2013). The CCA (2014) has published a series of recommendations and best practices to better evaluate groundwater resources and protect them from contamination. These recommendations focus on robust site characterization to inform groundwater monitoring system designs and to consider the multi-layered aspects of most groundwater flow systems. Initial characterization of the subsurface geologic, hydraulic, and hydrochemical complexity and anisotropy is important to design effective

groundwater monitoring networks. These networks can target specific zones with elevated risks of contamination; whether they bare threats from surface activities or from fugitive gas migration from below the freshwater zone (CCA, 2014). Recent literature has shown concerns surrounding leaky casings from improperly sealed wells (Dusseault & Jackson, 2014; Dusseault et al., 2014), leakage due to natural or induced seismicity (Kang et al., 2019), methane emissions from abandoned wells, idle wells not currently producing or orphaned wells (Kang et al., 2014; Kang et al., 2017; Lebel et al., 2020), and methane increases associated with wells intersecting faults (Li et al., 2016). All of the above has resulted in a strong interest in baseline groundwater studies to identify natural hydrochemistry and potential migration pathways that hydrocarbons, reservoir fluids and fracturing chemicals may utilize to contaminate shallow freshwater resources (Jackson et al., 2013; Uwiera-Gartner, 2013; Vengosh et al., 2014; Mcintosh et al., 2018). One approach to determining the impacts of shale gas and petroleum development in a region is to install multi- depth groundwater monitoring systems at several locations, creating networks that provide 3D monitoring of porewater pressure and chemistry and can be tracked over time. Multi-level systems (MLSs) should be tailored to the geologic heterogeneity of the subsurface, creating robust three- dimensional monitoring networks useful to interpret 3D groundwater flow systems as presented by Patton & Smith, (1988), CCA (2014), Cherry et al., (2015) and Cherry et al., (2017). High-resolution site characterization is particularly important in fractured bedrock systems, as flow is often controlled by discrete fractures, and the connectivity of these fractures has been shown to control hydrogeologic unit (HGU) boundaries in layered sedimentary rock aquifers (Meyer et al., 2008; 2014; Parker et al., 2012; Runkel et al. 2018). These bedrock aquifers often exhibit distinct fracture networks with strong horizontal and vertical anisotropy. This anisotropy is important at the HGU scale, where individual fracture pathways and connections dictate how the migration of fluids, including immiscible fluids like stray gas, are directed in the subsurface. Fractures can strongly influence flowpaths from recharge to discharge zones, as shown recently by Meyer et al. (2016) and more generically by Freeze & Witherspoon (1967). Fracture networks in sedimentary rocks are often complex and can be present due to variations in local deposition, lithification, cementation, fracture patterns or post-depositional deformation (Meyer et al., 2008; 2014; 2016; Shultz et al., 2017; Underwood et al. 2003). Maxey (1964) first noted the importance of flow system hydraulics for informing hydrostratigraphic units that are distinct from lithostratigraphic units. These units are informed by flow system conditions, emphasizing the hydraulic head distribution in concert with hydrogeologic property variability. Despite this, most hydrogeologic 3D static conceptual models rely primarily on lithostratigraphy to predict HGU boundaries (Seaber, 1988). It has been recently shown that static conceptual models of flow systems are best informed by a geologic framework, such as a sequence stratigraphic model, that is also informed by hydraulic data (Meyer et al., 2014, 2016; Runkel et al. 2018). This allows for contrasts in vertical hydraulic conductivity to be identified for aquitard and aquifer boundary delineation within the geological sequence due to control by fractures rather than lithology (Meyer et al., 2014, 2016; Runkel et al. 2018). Although lithology and hydraulic conductivity can be correlated, distinct hydraulic unit boundaries can be linked to fracture termination patterns at sequence stratigraphic surfaces (e.g., maximum flooding intervals, sequence boundaries), especially in clastic sedimentary sequences (Meyer et al., 2016). These zones tend to be very thin and difficult to pinpoint from visual observations, but this knowledge is important for designing 3

the placement of monitoring well intervals and seals to avoid cross-connecting distinct HGUs and blending between discrete zones (Meyer et al. 2014; 2016). Multiple borehole methods used in complement with a sequence stratigraphic logging framework has demonstrated improved data resolution for better identification of HGU boundaries, providing an improved representation of 3D groundwater flow in multi-layered sedimentary aquifer-aquitard systems (Parker et al., 2012; Meyer et al., 2014; 2016; Runkel et al., 2018). Bedrock groundwater systems are important to Canada (Rivera et al., 2003) and globally, hence, there is growing interest in improved characterization of bedrock aquifers and their role in maintaining ecosystem health, and as a possible source of clean sustainable drinking water. In Canada, this is especially true for rural and remote northern communities, where climate and land use changes are anticipated. Confined bedrock aquifers may represent a more secure source of freshwater relative to shallow aquifers or surface water due to the protection provided by an overlying aquitard. Of specific interest in the Fort Liard study area is the Dunvegan Formation, which locally resides between 0 to 180 metres below ground surface (mbgs), typically below glacial till or shale bedrock, and up to 750 mbgs within the broader transboundary region of the Liard Basin. This conglomerate and sandstone dominated formation is a well-known and often utilized freshwater aquifer in AB and BC (Stott, 1982; Lowen, 2011; Riddell, 2012), and its characteristics and features have been studied by several stratigraphers (e.g., Bhattacharya, 1994; Plint, 2000; Bhattacharya et al., 2016). Investigation of the depositional (deltaic lobes, floodplain deposits) and erosional features (incised channels) within these siliciclastic sedimentary systems informs the geometry of various depositional facies (deltaic, fluvial). These facies often correspond with hydraulic conductivity variability, often inferred or best understood in the horizontal direction; however, the bedding and sequence stratigraphic boundaries and internal stratigraphic layering may also influence the fracture connectivity and vertical hydraulic conductivity, providing a useful framework for assessing regional groundwater flow paths and groundwater residence times from recharge to discharge. Hydrogeologists rarely seek this sequence stratigraphic information at the basin scale (Anderson, 1989), yet the value of merging these depositional frameworks to inform hydrostratigraphy in sedimentary rock flow systems as proposed by Maxey (1967) has been demonstrated (Meyer et al. 2016; Shultz et al., 2017; Runkel et al., 2018). This represents continual steps toward the adoption of stratigraphic principles in groundwater conceptual model development. A sequence stratigraphic framework can be used to constrain hydraulic head and hydrochemistry trends spanning multiple hydrostratigraphic layers within a 3D flow system. 1.3 Study Objectives The Dunvegan Formation represents a potential source of freshwater that can help support ecosystems and northern community development. Its susceptibility to industrial activities and climate variability may be mitigated or accommodated with knowledge of the system characteristics and early detection of signals that could indicate negative and unsustainable impacts to the aquifer. The aim of this study is to characterize the internal architecture of the shallow fresh groundwater flow system near the Hamlet of Fort Liard (i.e., initially constrained to the upper 149 mbgs as defined by oil and gas drilling best practices (Mackenzie Valley Land and Water Board (MVLWB)) to link future groundwater monitoring locations within a robust 3D hydrogeologic

framework. Locally, this includes ~18 meters of Quaternary deposits (Smith, 2010) overlying the Upper Cretaceous Dunvegan Formation, which also has regional significance as a fresh groundwater aquifer-aquitard system. The main objectives of this thesis include: 1. Develop a sequence stratigraphic framework for the Dunvegan Formation within the Liard Basin and refine its depositional setting within the Western Canada Sedimentary Basin by outlining internal formation architecture, geometry and scales of spatial variability; 2. Convert the sequence stratigraphic framework to a hydrogeologic framework for the shallow freshwater zone (upper 149 mbgs) by combining newly collected and historic datasets that encompass the northern-most area of the Dunvegan Formation near Fort Liard, NWT, to better inform the Dunvegan Formation’s aquifer and aquitard boundaries and properties within the Liard Basin and broader Western Canada Sedimentary Basin; and 3. Design a robust groundwater monitoring network based on the developed hydrogeologic framework that will inform community-scale groundwater flow system characteristics (water level fluctuation, vertical and lateral hydrochemical variability, temporal shifts in flow velocity and direction) deemed vital in the NWT Water Stewardship Strategy (2018). 2.0 Approach and Methods 2.1 Site Description The Dunvegan Formation is located within the Western Canada Sedimentary Basin (Figure 1) and has been discontinuously mapped across YT, NWT, BC and AB (Figure 2) (Bhattacharya, 1994). The Dunvegan Formation was deposited as part of a large fluvial-deltaic complex during the Cenomanian Age (100.5 to 92.9 million years ago (Ma)) of the Cretaceous Period, when an internal seaway, the Cretaceous Western Interior Seaway (CWIS), was formed (Bhattacharya, 1989). The headwaters of this fluvial-deltaic complex resided within northeast BC and southwest NWT and flowed southeastwards (Figure 2; Figure 3), (Walsh et al., 2005; NEB et al., 2016). The northern extent of the Dunvegan Formation is historically described as being dominated by conglomeratic deposits of fluvial to piedmont alluvial origin, with the primary mode of deposition being alluvial fans (Stott, 1982). The Liard Basin is an asymmetric north-trending structural trough that is ~80 km wide and ~200 km long (Monahan, 2000). The west and northwest edges of the basin are bounded by the Mackenzie Mountains, which trend north-northeastwards, while the west to southwest edges of the Liard Basin are bounded by the Rocky Mountain Foothills, and trends north-northwestwards (Walsh et al., 2005; Jowett et al., 2007). On the eastern extent of the basin, the Bovie Structure separates the Liard Basin from the adjacent Horn River Basin (Walsh et al., 2005 & National Energy Board, 2016). The Liard Line, a major northeast trending transfer fault zone, runs through the Liard Basin, and another feature, the Liard Thrust, is present proximal to Fort Liard (Figure 2) (Douglas & Norris, 1976; Cecil et al., 1997; Grasby et al., 2016).

During the Cenomanian Age, the Dunvegan river system carried sediment from northeast BC and southeast Yukon, associated with tectonic collision and uplift, towards the CWIS. These tectonic processes that helped to build the Rocky and Mackenzie Mountains allowed for increased erosion and weathering to occur, resulting in an increase in sediment availability within the Liard Basin.

Southeast of the Liard Basin, preserved deposits are representative of the delta plain, delta front and prodelta, that have been split into ten different allomembers that are broadly related to transgressive-regressive sequences (Bhattacharya, 1994; Plint, 2000). Studies within the Fort St. John region have found channel bodies encased in floodplain deposits with incised valley systems being prevalent (McCarthy et al., 1999; Plint, 2002; Plint & Wadsworth, 2003; McCarthy & Plint, 2003). These valleys can be 15-41 m deep, averaging 21.3 m deep and are generally 1-2 km wide, but can be up to 10 km wide, locally (Table 1 and references therein). Within these valleys, valley infill is dominated by fine to medium grained sands (up to 97%), representing multi-storey point bars (Plint, 2002). Little research has been completed on the Dunvegan Formation within the Liard Basin since Stott (1982), due to its shallow nature (Figure 4), which makes it less important to O&G exploration, and the fact that it has not been utilized historically as a water resource in the area. In the southern reaches of the Dunvegan Formation in eastern BC and western AB, however, the deltaic system has been studied in detail (Bhattacharya, 1989; 1994; Plint, 2000; 2002; Plint & Wadsworth, 2003; Plint et al., 2011; McMechan et al., 2012; Riddell, 2012; Miall, 2016). The complex nature of the Dunvegan Formation, which is expected to extend northwards into the Liard Basin, is illustrated by highly anisotropic sand and gravel deposits with complex stratigraphic boundaries expected to greatly influence groundwater flow system characteristics. The Dunvegan Formation, deposited over ~2 Ma, was subsequently buried and lithified over the following ~95-100 Ma (Bhattacharya, 1994), before erosion and uplift brought these strata to the surface, where today they act as some of the most important freshwater bedrock aquifers in northeast BC (Riddell, 2012). The Dunvegan Formation is the most productive bedrock aquifer unit within the Peace River Region, ~500 km southeast, where it exists in the shallow subsurface. Within the Liard Basin, the Dunvegan Formation is overlain by the marine shale-dominated Kotaneelee Formation and underlain by the marine shale-dominated Sully Formation, both considered regional aquitards (Riddell, 2012). Secondary porosity in the Dunvegan has been found in the form of fractures that, when present, dominate groundwater flow (Lowen, 2011; Riddell, 2012). Within the Fort Liard region, the Mackenzie and Rocky Mountains act as important bounding features that could influence recharge dynamics, as well as the depths and residence times of the fresh groundwater flow system. Additionally, the presence of major structural features such as the Liard Line, Liard Thrust and Bovie Structure in the study area could have a marked impact on groundwater flow as barriers and/or conduits influencing contaminant migration within the region and within the Dunvegan Formation. These structural features are in addition to the natural anisotropy of the Dunvegan Formation, such as internal channel deposit heterogeneity associated with its deposition in variable flow regimes, which are likely to present complex aquifer and aquitard layering, potentially building natural system resilience or inherent susceptibility. Runkel et al. (2006) and Meyer et al. (2016) has also shown that these stratigraphic features often play a major role in fracture abundance, propagation and orientation, creating sequence stratigraphic boundaries that are coincident with hydrogeologic boundaries, making detailed understanding of the stratigraphic complexity vital (See Appendix A for further background information). 2.2 Study Approach This study focuses on the Fort Liard region (Figure 5) and uses a discrete fracture network-matrix (DFN-M) approach (Parker et al., 2012) for sedimentary rock aquifer-aquitard systems that utilizes multiple complementary tools and borehole methods to assess flow system attributes and parameters for key processes. This field approach is aimed at collecting samples and data at

multiple scales using multi-disciplinary tools (hydraulics, geology, geophysics, hydrochemistry) to build process-based conceptual site models (CSMs) for complex fractured porous rock systems (sedimentary rocks). The CSMs will aid in designing and building monitoring wells within the fresh groundwater zone with improved precision and accuracy relative to conventional monitoring wells. This shallow depth is regulated as less than 149 mbgs by the MVLWB. The work starts with continuous core subjected to cm-scale logging at surface for lithology and depth-discrete features (e.g. fractures), followed by a suite of borehole logging methods tailored to the investigation goals and borehole stability conditions as described in the Methodology section. The general plan for building the groundwater monitoring network using this DFN-M investigative approach consists of infrastructure installed in boreholes to obtain high resolution vertical profiles of hydrochemistry, hydraulic head and temperature at five locations surrounding the Hamlet of Fort Liard (Figure 5). High-resolution borehole and site-specific information will be combined with insight obtained from surface-based electrical resistivity tomography (ERT) surveys that were completed at these five potential drill sites (Figure 5), as well as with historical outcrop descriptions and well logs (Figure 2), to achieve a regional understanding of the sequence stratigraphic, paleohydrologic and basin-scale properties of the Dunvegan Formation extended to its northern extent in southwestern NWT. ERT locations are distributed throughout the study area in order to provide spatial coverage across faults, structures and to capture Dunevegan variabilty (Figure 5). This study presented herein was performed as an initial stage of the proposed plan where a single cored hole was drilled at one of the five ERT locations. Combining the insights from this initial cored hole with the geophysical datasets and previous geologic logs from numerous Dunvegan outcrops in the region provide the basis for an initial CSM and informing the methodologies best suited for the future installations proposed for the robust 3D monitoring network. These five future drilling locations will have continuously cored boreholes with a full suite of hydro/geophysical logs collected. These datasets will allow for a high-resolution MLS designed for groundwater sampling and advanced hydrochemical analyses with complementary continuous (dynamic) monitoring of hydraulic head through deployment of sensors at discrete depth intervals within the Dunvegan Formation. This future monitoring system will be used to assess the dynamic nature of the groundwater flow system in response to a range of natural and anthropogenic forcings (barometric pressure, recharge, river stage, groundwater pumping, fracking and natural seismic events) over time. These data will ultimately inform the hydrogeologic CSM for representation in numerical flow models. 2.3 Methods 2.3.1 Bedrock Characterization Continuous wireline rock core diamond drilling was completed from August 7th to 19th, 2018, using a conventional track-mounted CCME 650 rig, equipped with an HQ3 triple tube core barrel system with diamond-bit cutting shoe. This system produced a 4-inch (10.16 cm) diameter cored hole, with 2.5-inch (6.35 cm) diameter core. Polymer drilling muds were used only when necessary to maintain hole stability and improve core recovery, with the aim of minimizing alterations to the permeability and hydrochemistry. Fresh water from the Liard River was used as the primary drilling fluid to cool the bit and circulate cuttings to surface. Drilling occurred at two locations at a Waste Disposal Facility, identified as NWT01-A and NWT01, located 100 m apart (Figure 5).

2.3.2 Core Logging and Sampling All recovered core was photographed and logged on site, using a graphical logging template based on a relational database structure and included primary and secondary lithology, Munsell colour, grain size, sorting, roundness, contacts, cementation, sedimentary structures, bedding structures, clast size, and shape, as well as the total length of core recovery per run, Rock Quality Designation (RQD) (Deere & Deere, 1988) and position and orientation of fractures with respect to the core axis (assumed vertical) and visual evidence for other potential flow features. Samples were collected for physical properties, mineralogy, porewater hydrochemistry and isotopes. Each lithologic sample was preserved by wrapping with aluminum foil, then Parafilm® wax and double- bagged in vacuum sealed mylar bags using a HIPPO automatic vacuum sealer – Model AS-V-320. Samples were frozen and shipped to the University of Guelph in an insulated freezer box packed with dry ice. Upon arrival, they were stored until the core samples were subsampled and prepared for a suite of laboratory measurements and moisture content. Twenty-two samples were selected from 13.76 meters of recovered core, representing 26.7% recovery, and preserved (see Appendix B for full suite of preparation and analyses details). The remaining core was photographed, retained in labelled wooden core boxes, and shipped to the University of Guelph. 2.3.3 Downhole Natural Gamma Logging A downhole natural gamma probe (QL40-GR) connected to a Mount Sopris winch and a Matrix depth encoder (Mount Sopris Instruments Inc., Denver, CO) was used to log NWT01. This probe measures the emission of natural gamma rays from various minerals in counts per second (cps). The presence of rocks or sediment with high potassium-bearing minerals (U, Th, K) (i.e., clay minerals) will result in increased emission of natural gamma rays. Due to unstable borehole conditions, two partial logs were collected within the 51.56 m deep borehole: the first within the outer steel casing with drill rods in place to a total depth of 48.16 mbgs; and the second, with the drill rods removed to a depth of 36.58 mbgs. The up-log for each run was recorded at a rate of 1 m/min with a 0.01 m sampling interval. 2.3.4 Sequence Stratigraphic Analysis A sequence stratigraphic analysis based on depositional environment reconstruction principles was conducted based on the methodology described by Shultz et al. (2017) and SEPM STRATA (2020). Relevant features included: major and minor lithology; clay content; matrix grain size and shape; clast lithology, abundance, shape, size; and sedimentary features. Contact relationships were noted and plotted in association with their depth to create a visual stratigraphic log, which allowed for easier inspection of core variability and patterns within a sequence or section of rock. 2.3.5 Physical Property Analysis Seven of the 22 rock samples were retained for physical property measurements including: • hydraulic conductivity (ASTM D5084) • gravimetric porosity, wet and dry bulk densities (ASTM D7263) • water content (ASTM D2216) • specific gravity (ASTM D854) • total organic carbon (TOC) (Walkley Black Method – solid-phase organic carbon) (Walkley, 1947)

A rock saw was used to prepare 6.35 cm diameter by 11-15 cm long samples that were submitted to Golder Associates Ltd. for the above physical property testing. These samples were then subsampled based on the ASTM guidelines referenced above. 2.3.6 Porewater Hydrochemistry The major ion hydrochemistry of porewater can provide insight into groundwater flow at the regional and local scales, and subsurface processes with depth (Parker et al., 2012). Pre-weighed 60 mL high-density polyethylene (HDPE) bottles were used for porewater hydrochemistry sample collection. Approximately 40 g of crushed rock was placed directly in the empty bottle and then weighed. The samples were left to dry in an oven at 40 °C until the weight equilibrated to a constant value. Once dry, samples were re-hydrated with ~20 mL of Millipore (nanopure) water and shaken for 24 hours on an orbital shaker. The samples were then centrifuged, extracted, and filtered before ion chromatography (IC) analysis. Samples were analyzed at the G360 Laboratory at the University + + + 2+ 2+ 2+ - - - - of Guelph for cations (Na , NH4 , K , MN , Ca and Mg ) and anions (F , Cl , Br , NO3 , PO4 and SO4). The laboratory methodology is described in Appendix C. 2.3.7 Surface Electrical Resistivity Surveys Electrical resistivity tomography (ERT) measurements were completed at five locations around the region of Fort Liard, NWT to assess variations in the depth and thickness of the Dunvegan Formation within the upper ~150 m. Each survey consisted of a 96-electrode multi-core cable laid out along a straight line using a 10 m electrode spacing resulting in a 950 m long array. Stainless- steel electrodes were attached to the cable using copper alligator clips. Each electrode was inserted into the upper 12-15 cm of soil. Data was recorded using a Syscal ProTM (Iris Instruments, Orleans, France) powered by a separate 12-volt (V) battery. A dipole-dipole array was collected at each location. All surveys were collected along the side of a gravel road. Electrical resistivity pseudosections were pre-processed using PROSYS II software (Iris Instruments) which included manual filtering to remove erroneous data points and apply topographic corrections. Elevation data was retrieved from GoogleEarth. Filtered datasets were exported to RES2DINV v.3.59 (Geotomo Software) for data inversion. Each dataset was inverted using a damped least-squares method (Loke et al., 2013) with the following main criteria: 4 nodes per unit electrode spacing to increase resolution; using the finest mesh to improve calculated apparent resistivity values; selecting robust inversion, which helped reduce the effect of noise within the data; using model cells with widths of half the unit spacing; and severely reducing the effect of side blocks on the inverse model. Various data inversions were performed using different model constraints to assess model reproducibility and overall data reliability. The inversion process was completed once the root mean squared error (RMSE) between the measured and calculated apparent resistivity data approached 3%, which is considered to be a reasonably low RMSE. However, some of the inverse models yielded RMSE values >3% due to noisier datasets but generally did not exceed 7.5% in this study. For these higher RMSE scenarios, the inversion process ceased when percent changes between iterations were less than 0.5%. Inverse models represent a smoothed 2D representation of the true subsurface electrical resistivity distribution (electrical properties of the geologic material). These models were used to delineate geologic boundaries, formation thickness and infer geometry, based on variations in porosity, lithology and mineralogy, and presence/absence of permafrost to support drilling and monitoring activities. 9

3.0 Results & Discussion 3.1 Stratigraphic Architecture of the Dunvegan Formation Continuous core was collected from NWT01-A and NWT01 to depths of 34.78 and 51.54 mbgs with total core recovery of 3.66 m (11.5%) and 13.76 m (26.7%), respectively. NWT01 will be the focus of subsequent discussion. Detailed lithologic and stratigraphic logging of NWT01 core and the NWT01 gamma log interpretation revealed two broad sections: an upper section composed of coarse-grained conglomerate interpreted to represent the upper Dunvegan Formation (6.8-40.2 mbgs), and a lower section composed of fine-grained sandstone interpreted to represent the lower Dunvegan Formation (40.2-50+ mbgs) (Figure 6) (See Appendix D for full-scale NWT01 stratigraphic log). The upper and lower Dunvegan Formations represent distinct depositional regimes within the broader Dunvegan Formation. The sedimentological features observed in the core (e.g., migrating barforms, climbing ripples, channel bank collapse features) with representative images of each provided in Figure 7 are consistent with sediment deposited within a fluvial depositional system, and will be discussed in greater detail in the following sections. Stott (1982) interpreted the Dunvegan Formation of the Liard Basin to be predominantly deposited by alluvial fan structures. Within this study, newly collected information supports the characterization of the upper Dunvegan Formation as coarse-grained, as noted by Stott (1982), but goes further by indicating that the upper Dunvegan Formation is likely represented by terrestrial tributary river channels, whereas the lower Dunvegan Formation is fine-grained and likely represents distributary channels and deltaic clinoforms. These interpretations were made in part based off sedimentological features observed in NWT01 core (Figure 7), while also relying on existing depositional knowledge of the Dunvegan Formation obtained from previously completed studies (e.g. Bhattacharya, 1989; 1994; Bhattacharya & Walker, 1991a, b; Plint, 1996; 2000; 2002). The upper Dunvegan Formation has bar features indicative of unidirectional flow and coarse-grain sizes representing high-energy. The location of these deposits near the headwaters of the paleo-Dunvegan drainage network provides a good case for these deposits being associated with terrestrial fluvial channels of a tributary nature. The lower Dunvegan Formation also exhibits fluvial-derived sedimentological structures, but of a finer-grained nature, being associated with a relatively lower-energy fluvial environment, though the presence of conglomerate stringers (Figure 6) indicates that these fluvial systems were still moving gravel-sized clasts at times. Their presence below the upper Dunvegan Formation deposits indicates they would have been deposited earlier. The depositional features noted (Figure 7) and associated depositional environment interpretations are consistent with outcrop and well logs from the Peace River Region, where detailed study has revealed the Dunvegan Formation of that locality to be associated with deltaic deposits and distributary channel systems (Bhattacharya, 1994; Plint, 2000). The upper Dunvegan Formation of the Liard Basin likely fed this deltaic system. Based on Walther’s Law, which states that any vertical progression of facies is the result of a succession of depositional environments that are laterally juxtaposed, it can be inferred that the lower Dunvegan Formation is an earlier representation of this deltaic system, when it was in its infancy and had not prograded as far to the southeast. This dynamic system evolved over time, funneling sediment from YT, NWT, and northeast BC to the southeast through fluvial bodies, which shifted progressively basinward over time, building on top of sediment previously deposited by this drainage system. 3.1.1 Upper Dunvegan Formation Within the upper Dunvegan Formation, 5 m of core was collected over a 33 m interval, representing only 15% recovery. The dominant lithology was conglomerate, with minor sandstone

(Figure 6). Poor core recovery is interpreted to relate to large clast size, poor matrix cementation and weathering from exposure at or near to surface during glaciation. The rock core that was recovered was comprised of medium to coarse grained sand matrix with clasts up to 3-5 cm in diameter, generally being subrounded-rounded. Clast fragments (seen as clasts with visible cut marks) of similar size were also observed, indicating the presence of clasts exceeding the core sample size. Recovered core was variably consolidated, with little recovery and several intervals composed of loose pebbles up to 5 cm in size with matrix material coated around some clasts. This matrix material was composed mainly of medium sand (250-500 microns). Clast lithology was generally intrusive and extrusive igneous rocks, sedimentary rocks, metasedimentary rocks, chert, quartz, and quartzite. Matrix material was generally composed of similar lithologies to the clasts, which is consistent with previous studies in the area (Stott, 1982). The dominant sedimentary structures included cross beds and planar beds. Cross set thicknesses were measured to be between 20 and 30 cm. Clastic bar-scale cross beds were also observed, along with imbricated clasts (Figure 7a, b). Generally, coarser-grained conglomerate was more poorly sorted when compared with finer-grained conglomerate. In unidirectional flows sorting decreases as shear stress increases, so the coarser conglomerates will be naturally more poorly sorted. The cross-sets, interpreted as migrating barforms and imbricated clasts, observed in the upper Dunvegan Formation (Figure 7a, b) indicate flow in terrestrial rivers with bars that migrated in space and time. This interpretation contrasts with Stott’s (1982) suggestion that the northern Dunvegan Formation was deposited mainly by alluvial fans, which generally contain angular clasts, coarsening upwards successions and are distinct based on the specific drainage they represent (Miall, 2010). This deposit exhibits more mature subrounded-rounded clasts, coarsening upward successions do not dominate and clast and matrix lithology is seen to be consistent across the outcrops and well logs where data is present. While alluvial fans are generally confined to within 1-10 kilometres from the mountain front, the upper Dunvegan Formation deposits span an area almost 100 km wide and several hundred km long, indicating they are more widespread than an alluvial fan model would allow (Miall, 2010). The presence of large clasts indicates a high energy environment where large grains were transported and deposited as bars. The upper Dunvegan Formation shows evidence of stacked higher-energy channel deposits based on a thick package of coarse-grained sediment (~33 m) with limited fining-upward deposits, which is consistent with stacked channel sequences that would have cannibalized and remobilized sediment from underlying channels. This matches the borehole natural gamma response, where average counts per second (cps) were quite low (15-60) for the upper Dunvegan Formation, representative of a clay-poor unit (Figure 6). The thick nature of this deposit could suggest deposition within an incised valley, where flow would have been funnelled into the valley allowing for thicker sediment accumulations, as seen in studies ~600-1000 km to the southeast (Plint, 2002; Plint & Wadsworth, 2003; Morgan et al., 2019). The thickness of this stacked channel sequence combined with the coarse-grained deposits suggests the presence of a high energy environment, a large sediment supply and ample accommodation space. It is not possible to estimate the paleochannel depth from the core alone due to the limited recovery; however, to deposit 30+ m of coarse-grained material an abundance of accommodation space would have been needed. Estimates from sequences observed in the natural gamma responses provide more detail and suggest potential paleodepths. The natural gamma log reveals four sequences within this 33.4 m portion of the profile measuring (from top to bottom) 8.2 m (6.8-15.0 mbgs), 8.0 m (15.0-23.0 mbgs), 5.0 m (23.0-28.0 mbgs) and 12.2 m (28.0-40.2 mbgs) (Figure 6, labelled 1-4). Channel deposits would have undergone

compaction during lithification. A 10% compaction correction factor can be applied to better reconstruct pre-compaction channel deposit thickness (Holbrook & Wanas, 2014). Applying this correction details that the upper portion of the Dunvegan Formation would exhibit paleo-river depths of 5.5-13.5 m, which is consistent with observations by Lin & Bhattacharya (2017) (Table 1 and references therein). The documentation of the geometries of these features allows for the accurate depiction of these channel structures and their lateral extent in the 3D CSM, directly informing the ability to predict flow pathways within the groundwater flow system. 3.1.2 Lower Dunvegan Formation Within the lower section of the borehole, 8.9 m of core was recovered over 9.8 m, representing 91% recovery. This marked increase in core recovery is interpreted to relate to fewer and smaller clasts, more competent rock and less weathering due to a lack of surface exposure. The core was dominated by sandstone with shale and mudstone (Figure 6). Shale and mudstone beds were generally soft and could be pulled apart or imprinted with a fingernail. Two fining upward successions were observed from 50.0-44.7 mbgs and 44.7-40.2 mbgs (Figure 6), with a basal conglomerate or clastic sandstone that fined upwards into a shale or mudstone, indicating deposition under a weakening energy or flow regime. Sandstones were predominantly medium sand (250-500 microns), fining upwards to fine sand (125-250 microns), and in a few instances very fine sand (62-125 microns). These two fining upward successions were also represented in the natural gamma log, where two upward increases in the cps corresponded to increases in clay content (Figure 6, labelled 1-2). Crossbedding was the predominant sedimentary structure, with ripples and planar beds also observed (Figure 7f, g). Within the finer sandstone and shale some soft sediment deformation structures were identified, including ball and pillow structures, slumping and bank collapse features (Figure 7c, e). Core slickensides, pyrite grains and coaly fragments were observed within the shale and mudstone intervals, indicating organic-rich, oxygen- poor environments that experienced periods of wetting and drying. Preserved intact root structures were also observed within the mudstone and fine-grained sandstone of the deeper fining upward sequence (Figure 7d), indicating these sediments were deposited along a vegetated channel bank, or in an area that supported vegetation growth at some point after deposition. These rooted claystone, or possibly immature paleosols, are poorly preserved, making it difficult to determine whether the sediments and associated flora were exposed aerially or were deposited/lived in shallow water. Additional features were observed in the core including potential crevasse splay or levee deposits, related to flow overtopping channel banks and sediment depositing into the adjacent floodplain. These features were interpreted based on observations of muddy and silty deposits with preserved root structures, consistent with channel bank deposits and channel fill deposits. Within and above these units were silt to very fine sand deposits that were graded and variably lenticular. Floodplain deposits were also present in the same area, also punctuated with these graded silt-very fine sand deposits, potentially indicating that as channel fill processes were occurring and the stream captured in the core was migrating, occasional high-flow events were leading to flow overtopping the channel bank and depositing sediment onto the channel levee or adjacent floodplain. Outcrop work would be helpful to better characterize these deposits on a larger scale. Each of these fining upward channel successions are approximately 4 to 5 m in thickness. After accounting for 10% compaction during lithification and diagenesis (Holbrook & Wanas, 2014) and noting modern-day analogues (Lin & Bhattacharya, 2017), these channels were likely 5 to 6 m deep. As outlined by LeClair & Bridge (2001) and Holbrook & Wanas (2014), measurements

of dune sets can be collected and through empirically derived relationships, converted to estimate paleo-channel depths. As a means of checking the above-measured channel depths based on fining upward channel successions, measurements of ten dune sets were collected within the two channel successions of the lower Dunvegan Formation, averaging 0.205 m in thickness, corresponding to a corrected story thickness of 4.6 m and a paleo-channel depth of 5.1 m (see Appendix E for tables and calculations) (LeClair & Bridge, 2001; Holbrook & Wanas, 2014). These finer-scale dune height measurements are consistent with paleo-channel depth estimates obtained from the lower Dunvegan Formation channels in NWT01 and from literature (Lin & Bhattacharya, 2017) (Table 1 and references therein). This understanding of channel geometries allows for their more accurate depiction within the 3D CSM, informing the geometry of hydrogeologic variability and flow system interpretations and comparisons between the upper and lower Dunvegan Formation. 3.1.3 Lithostratigraphic Model of the Dunvegan Formation Stott’s (1982) outcrop descriptions from the Liard Basin were converted from text to stratigraphic logs and combined with newly compiled information from the NWT OROGO database and Hayes (2013) (Figure 8) (Appendix F & G). These updated stratigraphic logs enabled a more visual interpretation of the variability within the Dunvegan Formation. Data tables were generated from these stratigraphic logs (Appendix H) to evaluate the dominant grain sizes and lithologies, as well as variation in lithology, unit thickness and sand/shale fraction, both spatially and with depth. These data were used to reconstruct the internal architecture of the Dunvegan Formation (discussed in more detail below). Some of the logs and datasets included information about the underlying, shale-dominated Sully Formation, which provided additional context surrounding the relationship and boundaries between these two units. Stott (1982) created a lithologic cross-section based on his early observations of the Dunvegan Formation provided here for easy reference in Figure 9a. His conceptual model illustrated the variability of the Dunvegan Formation at a regional scale, connecting similar lithologies across the Liard Basin based on outcrop scale lithologic logging. Although useful for depicting broad variability, this lithologic cross-section does not fit within a clear lithostratigraphic or sequence stratigraphic framework that would allow interpretation of depositional processes or local-scale geologic variability. The stratigraphic logs created in this study from Stott’s (1982) original text descriptions were positioned to generate a north-south cross-section of the Dunvegan Formation within the Liard Basin, with a focus on delineating the major lithostratigraphic units, detailing heterogeneity in the larger Dunvegan Formation and underlying Sully Formation (Figure 9b). This lithostratigraphic model is based on re-interpreted historical data, as well as lithostratigraphic data collected from NWT01. Upper Dunvegan Formation The upper Dunvegan Formation (33-177 m thick) is dominated by conglomeratic deposits, with abundant clastic sandstone and lesser amounts of siltstone and shale (Figure 9b). It is comprised of thick conglomeratic packages with clast sizes up to 6 inches (~15 cm). Although its coarse- grained nature persists across the Liard Basin, it shows significant variability, being massive, planar-bedded, cross-bedded, tabular, and laminated (Stott, 1982). Stott’s (1982) lithologic logs mention interbedded shale and siltstone, which are more pronounced within downhole well logs, illustrating the presence of individual channels, and amalgamated or stacked channel deposits (Stott, 1982; Hayes, 2013). Approximately 80% of the upper Dunvegan Formation is comprised of conglomerate and sandstone (83% and 17%, respectively) with the remaining 20% being siltstone or shale (Appendix H) (NWT01 core was 100% conglomerate (Figure 6)). Conglomerate 13

represents the dominant material within the upper Dunvegan, indicating a relatively high-energy environment that would have been able to transport clasts up to 6 inches in size. The stratigraphic model based on historical core records alone is not of sufficient resolution to support or refute the claim that the Dunvegan Formation within the Liard Basin was deposited mainly through alluvial fan processes. Lower Dunvegan Formation The lower Dunvegan Formation (10-83 m thick) is dominated by fine-grained sandstones and is interbedded with siltstone, shale and occasional conglomerate higher in the sequence (Figure 9b) (Stott, 1982). Stratigraphic logs and well logs (Appendix G) exhibit signatures of coarsening- upward parasequences, which are consistent with clinoform structures related to prograding deltaic deposits studied by Bhattacharya (1994) and Plint (2000; 2002). Specifically, these features were noted in the lithologic logs as interbedded sandstone and shale units, with the sandstones being laminated and indicative of delta-front or shoreline deposits in some localities (Hayes, 2013). Approximately 80% of the lower Dunvegan Formation is comprised of conglomerate and sandstone (15% and 85%, respectively) with the remaining 20% being siltstone or shale (Appendix H) (NWT01 core was 82% conglomerate and sandstone (15% and 85%, respectively) with the remaining 18% being siltstone or shale (Figure 6)). Middle Shale Layer A middle shale layer separates the upper and lower Dunvegan units and ranges from 9-38 m in thickness (Figure 9b). In some of Stott’s (1982) outcrop descriptions a thick shale layer is observed, while in others a middle shale band is inferred and described as “talus covered, looks like shale” or simply, “covered” - likely corresponding to this middle shale layer despite being poorly preserved in outcrop. As the exact upper and lower bounds may be obscured by talus, vegetation or erosion, the total thickness and variability in thickness of this shale layer remains an estimate. Work completed in this study indicates that from a lithostratigraphic perspective this shale band appears to represent a continuous layer separating the upper Dunvegan and lower Dunvegan Formation across the Liard Basin, though it was not seen or recovered at the NWT01 core location (Figure 6). 3.1.4 Sequence Stratigraphic Model of the Dunvegan Formation The observed sedimentological features within the lower Dunvegan Formation (i.e., cross-beds, ripples, soft sediment deformation structures and rooting structures) and the upper Dunvegan Formation (i.e., cross-beds, migrating barforms and imbrication) at NWT01, shown in the photographs in Figure 7, together with lithostratigraphic information from historical logs and outcrops (Stott, 1982; Hayes, 2013) (Figure 9a, b) was used to generate a sequence stratigraphic model of the Dunvegan Formation showing internal geometry of bedding structures within the Liard Basin (Figure 9c). The sequence stratigraphic model depicts a transitional deltaic to terrestrial-fluvial environment, where the deltaic environment is represented by the lower Dunvegan Formation and the terrestrial-fluvial environment is represented by the upper Dunvegan Formation. Within the upper Dunvegan Formation, as discussed above, the presence of cross-beds, interpreted as migrating barforms and imbrication features support a fluvial over alluvial fan depositional

environment. These features were not distinguishable from historical studies due to a lack of facies architecture work completed at the time. Based on Stott’s (1982) data, combined with newly collected core and gamma data from this study that show evidence of sedimentary features (imbricated clasts, migrating barforms, cross-beds) representative of unidirectional flow in a fluvial environment, the upper Dunvegan Formation is most likely associated with a fluvial, terrestrial, tributary river system, bounded on the west by the Rocky and Mackenzie Mountains, and on the east by the topographically elevated Bovie Structure. This setting would have constrained the southeastward flowing Dunvegan river system within an 80 km wide subsiding valley (Monahan, 2000; Walsh, 2004) (Figure 3). Moving deeper in the system and back in time, the lower Dunvegan Formation would have been dominated by delta front and delta plain deposits consistent with studies of the Dunvegan Delta in the southeast (e.g., Bhattacharya (1989; 1994), Walker & Bhattacharya (1991a, b), Bhattacharya et al. (2016), Lin & Bhattacharya (2017), Plint (1996; 2000; 2002), Plint & Wadsworth (2003), Hay & Plint (2009) and Plint et al. (2001, 2011)). However, the delta proximal to Fort Liard is older within the Liard Basin as it is proximal to its sediment source area. Borehole NWT01 sampled 10 m into the lower Dunvegan Formation, capturing two partial channel fill sequences that are consistent with a distributary channel environment. For instance, preserved rooted claystones inferred to be potential immature paleosols, crevasse splay and channel-bank collapse structures provide evidence of a fluvial environment with some channel stability (Figure 7d, e). The Dunvegan Delta, as studied in the Peace River Region and in Western AB deposited fine to medium grained sand clinoforms over previously deposited finer sediments (silt and clay size particles) associated with earlier deltaic progradation (Bhattacharya, 1994; Plint 1996; 2000), which corresponds to the Upper Sully Formation. This supports the hypothesis that the Upper Sully Formation shales are genetically linked to the Dunvegan Formation, and therefore, represent the early stages of the Dunvegan Delta’s progradation (Jowett, 2004). The contact between the Upper Sully Formation and lower Dunvegan Formation is expected to be variable and interfingered due to the transient nature of (paleo-)shorelines and deposits associated with this dynamic part of the depositional system, which the lower Dunvegan Formation and Upper Sully Formation would have straddled. The presence of a continuous shale unit separating the upper and lower Dunvegan across the Liard Basin (Figure 9b) is unlikely given the transitional deltaic to fluvial depositional environment identified herein. While the presence of this lithostratigraphic shale layer is theoretically plausible, it would require major changes, such as widespread marine flooding surfaces to have been preserved elsewhere in the WCSB, which are not seen. Additionally, there is no evidence of a continuous shale feature within the core or natural gamma logs from NWT01 (Figure 6). Based on a sequence stratigraphic framework, the shale unit separating the upper and lower Dunvegan is more likely representative of a series of gently dipping shale beds, associated with the lower Dunvegan Formation (Figure 9c). This sequence stratigraphic framework implies that these shale beds would be interbedded with sandstone-dominated clinoform deposits, which have not been observed in the historical data or this study, but are consistent with the depositional model studied in detail farther to the southeast (Bhattacharya, 1994; Plint, 1996; 2000). Multiple gently dipping shale beds could also provide an explanation for why the lithostratigraphic middle shale layer had

thicknesses from 9-38 m, with outcrop and well logs intersecting different shale layers of different thicknesses. This interpretation indicates a smooth upward transition from deltaic to terrestrial deposits (lower Dunvegan to upper Dunvegan) as described within Dalrymple & Noel (2010), and thus, would make these series of gently dipping shale beds genetically linked to the lower Dunvegan Formation. Combining the lithostratigraphic lower Dunvegan Formation and Middle Shale Layer results in a sequence stratigraphic lower Dunvegan Formation (Figure 9c) that is thicker and has different relative proportions of lithologies compared to that of the lithostratigraphic model (Figure 9b). Based on this sequence stratigraphic interpretation, the proportion of conglomerate and sandstone (80%) to siltstone and shale (20%) noted for the lower Dunvegan Formation would decrease to 53% conglomerate and sandstone (14% and 86%, respectively) to 47% siltstone and shale within the sequence stratigraphic framework, indicating a much finer grained unit overall (Appendix H). This transitional deltaic to terrestrial-fluvial depositional environment differs from that proposed by Stott (1982), Bhattacharya (1994), Riddell (2012) and others, which indicated the primary mode of deposition within northeast BC and NWT to be alluvial fans (Figure 9a vs. Figure 9c). While alluvial fans likely existed in the most northerly headwater regions of the Dunvegan river system within and near the Mackenzie and Rocky Mountains, re-examination of Stott’s work alongside NWT01 core marked by cross-beds, climbing ripples, migrating barforms and imbricated clasts, points to a fluvially dominated depositional environment within the majority of the Liard Basin. Renewed tectonism during the Mid-Cretaceous (Stott, 1982; Gov. of Yukon, 2001) led to a continuous sediment supply from the mountains to the west, which when combined with a regression of the CWIS could have resulted in a shift from lower Dunvegan Formation sandstone- dominated clinoforms and distributary channel deposits to upper Dunvegan Formation conglomerate-dominated channels. The sequence stratigraphic framework discussed herein focuses on the depositional environment and the role existing structural features could have played in facilitating and shaping the depositional system. This framework does not discuss in detail post-depositional deformation or alteration associated with continued structural evolution, locally or regionally, within the Liard Basin. Some initial discussion on the importance and potential impacts of post-depositional structural evolution is presented below, which will be advanced through an adjacent study focusing on the collection of high-resolution airborne electromagnetic data. This airborne data will help to improve data coverage around the Fort Liard region such that the impact of relevant structures, such as the Bovie Structure, Liard Thrust, Liard Line and broader Liard Fold and Thrust Belt can be studied and interpreted with a focus on their impact on the Dunvegan Formation and associated groundwater flow system. 3.1.5 The Dunvegan Formation within the Western Canada Sedimentary Basin Distal regions of the Dunvegan Formation are dominated by deltaic deposits (Figure 10a, b) (Bhattacharya, 1989; Bhattacharya & Walker, 1991 a, b). These deltaic deposits downlap onto the Fish Scales Upper (FSU) marker, which has been delineated as the base of the Dunvegan Alloformation (Figure 10b) (Plint, 2000). Within the Liard Basin the Upper Sully Formation rests on the FSU marker, though it is termed the Fish Scale Member (FSM) within the Liard Basin (Jowett, 2004). These more southeasterly deltaic deposits often have a composition of 50%

sandstone, a much higher proportion than the muddier deposits of the Mississippi Delta (Bhattacharya, 1989), but similar to the 53% conglomerate and sandstone observed within the lower Dunvegan Formation of the Liard Basin, which is consistent with the interpretation that the lower Dunvegan Formation within the Liard Basin has a potentially similar depositional environment and sedimentary makeup to that of the Dunvegan Formation deltaic deposits in the Peace River Region and western AB. These more southeasterly deltaic deposits have been traced from western AB into northeast BC, within the Peace River Region, where paleovalleys, trunk streams and distributary channels have been identified in addition to deltaic deposits (Figure 10a). These fluvial channels, which are dominated by fine to medium grained sandstones (125-500 microns) (Table 1) show that paleo- rivers would have been 5-15 m deep, with some paleovalleys reaching 40 m deep, with widths <100-230 m for individual channels or 0.5-10 km for channel belts (Table 1), possibly being up to 15 km in width (Bhattacharya personal comm., 2020). Paleovalley systems have been delineated with anastomosed and meander channels preserved (McCarthy et al., 1999). The meandering river channels are represented by fine to medium grained sand and laterally accreting point-bar deposits, with one example preserving multi-storey sand bodies up to 35 m in thickness and 1 km in width (McCarthy et al., 1999) (Table 1). The base of these sand bodies were scoured into the underlying sediments, with the overall sand body geometry showing two to five stories, separated by thin intraclast layers, similar to the stratigraphic and depositional architecture observed within the upper Dunvegan Formation at NWT01, despite the Liard Basin deposits having coarser grain sizes and being more conglomerate dominated. This implies consistency between the depositional models of the Dunvegan Formation within the Peace River Region and the Liard Basin, as outlined in this study. There is a gap in the rock record between the Peace River Region and the Liard Basin (Figure 2, Figure 10) (Bhattacharya, 1994), where high energy environments led to deposition of coarse- grained material. While coarse grained sediments persist throughout the Liard Basin, there is a marked reduction in grain size toward the Peace River Region (Stott, 1982). The lack of downstream fining within the Liard Basin indicates that the mountains likely provided a continuous supply of coarse-grained material to the Dunvegan river system, which was sufficiently steep and flowing at a sufficient velocity to transport this material along the length of the Liard Basin. This indicates that the transition from a gravel-dominated to sand-dominated depositional system is not present for the upper Dunvegan Formation within the Liard Basin, and occurs farther to the southeast, once the continued input of sediment from the adjacent mountains diminished, channel slope and velocity decreased and downstream fining processes became dominant. This increase in sediment availability, coupled with continued subsidence, allowed for large volumes of sediment accumulation within the Liard Basin, with some upper Dunvegan Formation conglomerate-dominated successions exceeding 100 m in thickness (Stott, 1982; Bristow & Best, 1993). Increased sediment accumulation results in higher avulsion frequency, as sediment rapidly fills topographic lows, causing a shift in channel-belt location towards a new topographic low (Bristow & Best, 1993). This pattern would have created clustered channel deposits, hosted within floodplains (Hajek, Heller & Sheets, 2005), which would have flowed southeastwards along the Mackenzie and Rocky Mountains, feeding the Dunvegan Delta.

By integrating NWT01 at the northern extent of the Dunvegan Formation with historical data, a clearer depiction of the Dunvegan Formation depositional system within the Liard Basin and WCSB was achieved, bridging knowledge gaps and allowing similarities between analogous deposits in different regions within the Dunvegan Formation to be acknowledged. 3.2 Hydrogeology of the Dunvegan Formation within the Liard Basin Geologic and sequence stratigraphic boundaries can aid delineation of hydrogeologic units (HGUs) (Parker et al., 2012; Meyer et al., 2014; 2016). The hydrogeologic characteristics of the Dunvegan Formation will be evaluated to delineate bedrock aquifer and aquitard units based on physical property analysis and surface geophysical measurements in the Fort Liard area. 3.2.1 Hydrogeologic Implications of the Sequence Stratigraphic Conceptual Model A 3D conceptualization of the subsurface has been created to illustrate the spatial relationship between the upper and lower Dunvegan Formation within the Fort Liard region (Figure 11). This local conceptual model illustrates the nature of channel deposits in cross section, along their length and in plan view within a channel belt. It also shows how channels can interact within a stratigraphic layer and between stratigraphic layers, potentially creating a well-connected 3D groundwater flow system. However, these fluvial depositional environments have a large degree of variability that could present localized barriers to flow and build natural protection into the system through segmentation of different aquifer units. Aquitard boundaries could be associated with floodplain deposits that encase preserved channels, as well as internal variations within channel deposits. Bristow & Best (1993) describe that the individual fluvial channel type or style is not the defining factor in channel preservation, but that channel morphology preservation is instead based largely on the rates of aggradation, avulsion and migration that existed during and post deposition. Fluvial systems commonly stack on top of one another and in the process amalgamate, cannibalize, and rework some of the sediment, creating thick vertically connected sequences (Bristow & Best, 1993). This style of deposit, dominated by interconnected fluvial channels, is consistent with the lithostratigraphic and sequence stratigraphic observations of the upper Dunvegan Formation to date. Increased subsidence in the Liard Basin during the Cretaceous created accommodation space and an abundance of sediment availability allowed for this space to be filled through aggradation of multiple generations of Dunvegan river system channels, which in turn exhibited processes of amalgamation and reworking (Figure 6, Figure 9c, Figure 11). While this provides a qualitative understanding of the depositional dynamics at play in the upper Dunvegan Formation and how these channels may present themselves in the rock record, it does not allow for more quantitative or precise interpretations of what the exact depositional patterns may be and how this could affect groundwater flow and contaminant migration. Due to the complexity of these systems, where internal channel-deposit and adjacent overbank and floodplain deposit heterogeneity can create variability in hydraulic conductivity that spans orders of magnitude over small spatial areas, high- resolution study of each individual system is important to understand potential aquifer and aquitard boundaries and properties. Despite this, the observed deposit style and structure thus far point to a productive aquifer unit. This is supported by several studies that have been completed examining the hydraulic

connectivity of channelized deposits. Larue & Hovadik (2006) completed a detailed modelling study looking at the connectivity of channelized reservoirs. They examined and built on older studies (Allen, 1978, 1979, King 1990, Allard & HERESIM Group, 1993) that focused on 2D connectivity as a function of sand fraction and found that the relationship between the sand fraction and connectivity percentage created an S-type curve. When sand fractions are >75%, channel connectivity reached 95%; at sand fractions from 50% to 75%, connectivity ranged from 0% to 100%; whereas for sand fractions <50%, connectivity was close to 0%, indicating channel bodies were isolated from one another. In 3D, Larue & Hovadik (2006) found that stratigraphic connectivity usually exceeded 90% when sand fraction was greater than 30%. Applying these findings to the 80% sand fraction for the upper Dunvegan Formation in this study, it can be inferred that in 2D and 3D space, connectivity should be close to 100%. Lower Dunvegan Formation deposits have the potential to be productive aquifers, as is the case in the Peace River Region, where deltaic and medium-grained fluvial deposits, similar to those seen within the lower Dunvegan Formation, are the most productive regional bedrock aquifers (Lowen, 2011; Riddell, 2012). While the deltaic clinoforms (i.e., sandstone) of the lower Dunvegan in the Fort Liard region may be laterally extensive, their relative vertical separation by flooding surfaces (i.e., mudstone), suggests there may be limited vertical connectivity between adjacent units. This is seen in the data collected (Appendix G) and supported by the literature (Bhattacharya, 2010). However, there are some instances within the outcrop and well logs that appear to show multiple clinoforms stacked on top of each other without a separating flooding surface, showing that there is spatial variability between the successions. Further, the presence of stacked distributary channels, which are preserved in NWT01 core, could represent potential aquifer material based on matrix hydraulic conductivity measurements from NWT01 within the lower Dunvegan Formation. Given the depositional complexity of the upper and lower Dunvegan Formation it is important to hydraulically inform the sequence stratigraphic model to properly delineate HGUs and aquitard boundaries (Parker et al., 2012). The local geologic variability was evaluated using electrical resistivity tomography (ERT) measurements at potential drilling locations around the Hamlet of Fort Liard. These geophysical data together with continuous core logs, provided insights into the thickness and lateral extent of the upper and lower Dunvegan Formation, and aided in the interpretation of HGUs (Parker et al. 2012). 3.2.2 Spatial Extent of the Dunvegan Formation near Fort Liard Electrical resistivity tomography (ERT) surveys were completed at five locations around Fort Liard to assess the spatial extent and geometry of the Dunvegan Formation (Table 2) (See Appendix I for full results). The ERT results at NWT01 with corresponding core and gamma log is shown in Figure 12 (R1); complete ERT results with geological interpretations (survey locations shown in Figure 5) are summarized in Figure 13. These ERT measurements reveal variability in bedrock electrical resistivity across the Fort Liard region. The ERT depth of investigation ranged from 150-180 mbgs. Based on the anticipated extent of the Dunvegan Formation (Figure 5), it appears to be much deeper west of the Liard River (R3, R4) compared to the east along the Liard Highway (R1, R2, R5). Surveys collected along the Liard Highway reveal a subcropping Dunvegan Formation beneath Quaternary sediments. This is consistent with the extent and

potential thickness of the overlying Kotaneelee Formation within the sedimentary basin as outlined by Douglas & Norris (1976). Site R1 was centered over NWT01, which enabled direct comparison between the electrical resistivity and the lithostratigraphy observed in the core (Figure 12). Sharp resistivity contrasts were observed within the upper 100 m. A thin surficial layer of low resistivity (20-50 ohm m) extends across the entire section that gradually thickens from <5 to 20 m from west to east. This upper layer is underlain by a high-resistivity zone (200-1000 ohm m) with a thickness ranging from 50-80 m. The upper boundary of this resistive layer is relatively sharp and gently dips from west to east, while the lower boundary is more gradual and undulates resulting in varying unit thickness. A relatively thick low resistivity zone (<50 ohm m) with minimal internal variability dominates the lower portion of the section (Figure 13a). The electrical boundaries within the upper 100 m were superimposed and aligned with the stratigraphic and natural gamma logs from NWT01, which enabled a geologic interpretation of electrical units across the region (Figure 12). A geological interpretation of the surface geophysics at Site R1 (Figure 11a) suggests the upper Dunvegan Formation (7-40 mbgs from NWT01) corresponds to the more resistive zone demarcated by the red colours. Conversely, the lower Dunvegan Formation (40-50 mbgs from NWT01) corresponds to the less resistive zone demarcated by orange to light blue colours. The reduction in resistivity within the lower Dunvegan Formation could indicate a gradual increase in shale or clay-rich rocks with depth relative to adjacent locations along the line where the boundary is much sharper (e.g., 225 – 435 m). The upper Dunvegan Formation exhibits a sharp contact with the overlying Quaternary sediments, indicating that these units have a strong electric contrast, inferred to represent a geologic contrast as well. The lower Dunvegan Formation appears to extend to a depth of 100 mbgs, gradually becoming less resistive. This observation would be consistent with a lower energy system consisting of fining-upward channel fill deposits with higher clay fractions, as noted in NWT01 core and gamma logs. The Sully Formation is expected to be present at the base of the Dunvegan which would lead to further reductions in electrical resistivity. Site R2 (Figure 13b) reveals a more complex system. Here, a thin surficial layer of low resistivity (20-50 ohm m on the eastern portion of the section and 50-200 ohm m on the western portion of the section) extends across the site and maintains a thickness of 8-12 m. This upper layer is underlain on the western side of the section (0-400 m) by a relatively thin high-resistivity layer (200-1000 ohm m) ranging from ~10 to 35 mbgs. A high-resistivity layer (200-500 ohm m) exists toward the east which dips and thickens from east to west (from 10-35 mbgs on the eastern edge to 50-180 mbgs on the western edge). The resistivity of this layer gradually decreases (~100-200 ohm m in the centre of the section to 50-150 ohm m on the western extent). Resistivities below this layer are relatively lower (20-50 ohm m), aside from some variability in the lowermost portion of the model. Based on these data a thin Quaternary layer extends across the transect to depths of 8-12 mbgs. This is underlain on the western portion of the section by a thin layer (10 - 35 mbgs) interpreted to represent the upper Dunvegan, and on the eastern section by a layer interpreted to represent the lower Dunvegan. This lower Dunvegan unit gradually thickens from east to west as it dips beneath the upper Dunvegan from 10-35 mbgs on the east to 50-180 mbgs on the west. These two units are separated by an electrically conductive zone interpreted to represent an internal

shale layer, potentially representative of a dipping mudstone associated with the lower Dunvegan clinoforms outlined in the sequence stratigraphic framework (Figure 11). The slight increase in resistivity in the lowermost portion of this section is interpreted to be a more sand-rich unit possibly associated with the Sully Formation or a deeper fluvial unit (i.e., Sikanni Formation), but further data collection is necessary to ascertain this geologic architecture. Site R3 across the Liard River (Figure 13c) reveals several electrically distinct layers. A thin surficial layer of lower resistivity is present across the site from surface to ~10 mbgs with moderate internal variability; the eastern portion of the section (600-950 m) exhibits resistivities from 100- 1000 ohm m, while the western potion (0-600 m) exhibits resistivities from 20-150 ohm m. Based on the available geologic information (Douglas & Norris, 1976; Stott, 1982; Walsh, 2004) and accounting for trends between Site R1 and NWT01, this thin surficial layer (~10 mbgs) likely represents glacial and fluvial deposits. Below this uppermost layer is a much higher resistivity zone that extends from 10 to 30 mbgs. Layer resistivity range from 500-1000 ohm m toward the east (between 560-950 m) to 150-500 ohm m toward the west (between 0-560 m). The Wapiti Formation, which is comprised of electrically resistive sandstone, is known to be discontinuous in the area (Douglas & Norris, 1976) and appears to extend from 10-30 mbgs. This zone is underlain by a low resistivity unit (20-50 ohm m), interpreted as the Kotaneelee Formation that extends from ~30-180 mbgs, which contains a slightly more resistive lens (50-150 ohm m) from 360-640 m along the section. Resistivities show a slight increase (100-200 ohm m) at depths >180 mbgs, interpreted to mark the top of the Dunvegan Formation. This interpretation, specifically the presence of the Wapiti Formation near surface, does warrant additional explanation. While the elevation of this section is lower than those on the east side of the Liard River (R1, R2 and R5), which depict lithostratigraphic formations that are below that of the Wapiti and Kotaneelee Formation, the lithologic interpretations are associated with Douglas & Norris’ 1976 map which details that the Wapiti and Kotaneelee Formation were observed in outcrop along the Liard River’s western bank. The position of these formations at a lower elevation than older formations east of the Liard River is likely associated with the shape and plunge of the Liard and Petitot synclines, which could have resulted in the western limb of this syncline being at a lower elevation than the eastern limb, allowing for the Wapiti Formation to be present near surface, whereas it is eroded east of the Liard River. Based on present knowledge, this is the interpretation that was chosen. Potential alternative interpretations do exist and are noted below. The surficial unit could actually be the Dunvegan Formation, with the underlying unit being the Sully Formation, though this contradicts existing mapping studies (Douglas & Norris, 1976). The surficial unit could represent fluvial deposits associated with the Liard River, though the resistivity observed is higher than would be expected for uncemented sandstones. Further, this surficial unit could represent permafrost conditions at the site. While the region is known to contain discontinuous permafrost (VanGulck, 2016), no permafrost has been observed or noted proximal to the Hamlet of Fort Liard or these study sites. Additional field work, either through borehole drilling or further geophysical surveys, such as a seismic survey, could help to better elucidate the nature of this surficial unit and its connection to the larger structural and depositional history of the area. Site R4, adjacent the Liard River and north of R3 (Figure 13d), shows relatively low resistivity with limited internal variability across the section. There are two thin surficial units within the

upper 20 m with elevated resistivities between 360-600 m (50-150 ohm m) and 660-950 m (150- 1000 ohm m). However, low resistivities dominate much of the deeper sections ranging from 20- 50 ohm m to a depth of ~150 mbgs. A slight increase in resistivity (50-100 ohm m) is observed at depths >150 m. The two thin surficial units likely represent glaciofluvial or fluvial deposits, with the easternmost deposits associated with the Liard River. The underlying Kotaneelee Formation apparently extends to depths of ~150 mbgs where it is underlain by the more resistive Dunvegan Formation. Site R5 (Figure 13e) shows a relatively homogeneous and low resistivity unit (20-50 ohm m) across the entire section. Slight variations are observed between 260 m and 460 m along the section with resistivities varying between 20 and 50 ohm m. Based on geologic maps of the area (Douglas & Norris, 1976), the dominant bedrock formation is most likely the shale-rich Sully Formation which underlies the Dunvegan Formation. The absence of a high resistivity layer indicates that the Dunvegan Formation is not present at this location. The ERT results demonstrate variability in Dunvegan Formation depth, thickness, and character across the Fort Liard region. Although the Dunvegan Formation was not identified at Site R5, the ERT revealed the Sully Formation, which as a whole, is considered a regional aquitard (Riddell, 2012). The Upper Sully Formation is inferred to be genetically related to the lower Dunvegan Formation, indicating a possible hydraulic connection between these units. However, this hydraulic connection is not expected to extend into the marine-shale dominated Fish Scale Member and Lower Sully Formation. Site R1 and R2 reveal the stratigraphic architecture of the upper and lower Dunvegan Formation identified in the core and natural gamma logs at NWT01. The differing character of the upper and lower Dunvegan Formation between Site R1 and R2 could be associated with depositional variability, or post-depositional features, namely subduction, folding or faulting, potentially associated with the Bovie Structure, which is proximal to Site R2. While the ERT survey did support delineation of different geologic units, it was not able to provide insight into the internal heterogeneity and depositional structures (channels, clinoforms) that define these units. This internal complexity is important to understand and characterize the deposits and their depositional environment, which also subsequently plays a defining role on the groundwater flow system. Seismic geophysical surveys could be completed in future studies to better ascertain this level of detail. Additionally, while none of the ERT lines crossed regional structural features, the general dip of the deposits observed did match well with the mapped regions of the Liard and Petitot synclines, which have the Liard Thrust and Bovie Structure running through them and bounding them. Future surveys could be focused to better understand the above features and depositional complexities to better refine the sequence stratigraphic and hydrogeologic framework. 3.2.3 Regional Structural Features Prior to, during and after the deposition of the Dunvegan Formation, active tectonics were building the Mackenzie and Rocky Mountains, shaping the Liard and Western Canada Sedimentary Basins, and creating several structural features within the study area around Fort Liard (Government of Yukon, 2001). These structures had the ability to affect deposition of the Dunvegan Formation during its deposition and have the ability to affect the hydrogeologic system today. Although none

of the structural features described below were intersected by NWT01, regional geologic maps show their approximate position in the study area (Figure 5). The Mackenzie Mountains are located to the west and northwest of the study site and act as a topographically elevated feature, with various fault systems running along and through the mountain range. The Mackenzie Mountains would be an area of regional recharge, diverting water towards the Liard River, focusing infiltration along overland flow paths and through faults and fracture conduits. The Liard Line is considered one of the most prominent structural features within the Canadian Cordillera and has affected sedimentation and tectonics within the region throughout its history (Grasby et al., 2016). The Liard Line is a northeast-trending transfer fault zone that exists to the northwest of the Hamlet of Fort Liard and marks the structural transition between the Rocky Mountains and Mackenzie Mountains, represented by the depositional pinch out of Ordovician to Devonian strata to the southeast of this structure, whereas these strata are preserved north of the Liard Line (Cecil et al., 1997). Along the Liard Line, nine different thermal springs have been identified and studied to determine meteoric water circulation depth and water chemistry (Grasby et al., 2016; Ferguson and Grasby, 2017; Grasby et al., 2017). It was found that meteoric water circulated to depths in the range of 3.8 km, indicating hydraulically active faults and fractures. These thermal springs are located southwest of Fort Liard, in a region with more deformed bedrock; however, the proximity of these structural features to the study site is an important consideration for groundwater flow dynamics and premise for groundwater monitoring to assess changes over time. The Liard Thrust runs roughly north-south along the west edge of Fort Liard under the Liard River (Douglas & Norris, 1976), between ERT Site R4 and R5 (Figure 5). The Liard Thrust extends north towards the Mackenzie Mountains and south towards the BC border. This structure separates the Liard Syncline from the Petitot Syncline and extends through the Dunvegan Formation (Figure 4). The Bovie Structure runs north-south and is located ~3 km east of Site R2. The Bovie Structure is a regional feature of importance that existed before the deposition of the Dunvegan Formation and was reactivated ~15 Ma after Dunvegan deposition (MacLean & Morrow, 2004). This structure could have represented an accommodation zone that aided in trapping gravel and retaining coarse sediment within the Liard Basin. The Bovie Structure is a west-side down feature with structural elevation drops of up to 1200 m (MacLean & Morrow, 2004). Gas pools have been found along its length and much of the conventional and unconventional O&G exploration and development to date has been completed just west of the Bovie Structure within northeast BC, showing it serves as a low permeability feature (Figure 2) (Walsh, 2004). However, gas migration from depth to ~600 m has been observed, proving that parts of the Bovie Structure are or were hydraulically active. While no commercially exploitable O&G reservoirs have been found shallower than this depth, there is the potential that fugitive gas migration is still occurring at rates that could impact surficial freshwater resources or conditions, or rates could be modified with further deep oil and gas development. The Bovie Structure remains topographically elevated ~100 m compared to the surrounding areas. These local and regional structural features add complexity to the site-specific fracture networks and structural systems within the Dunvegan Formation, as well as the overlying and underlying

formations, offsetting hydrostratigraphic units, potentially affecting connectivity. While site-scale feature mapping and physical property analysis can assist in creating an understanding of the localized groundwater flow system, it must be done with recognition of these larger scale structural features that commonly serve as either higher or lower hydraulic conductivity features influencing recharge rates and flow paths. Knowing their location will partly inform specific monitoring infrastructure placement. These features could have a significant influence on recharge dynamics, groundwater residence times and local, intermediate, and regional groundwater flow pathways. 3.2.4 Aquitard Boundaries and Integrity The Kotaneelee Formation is a marine-shale dominated unit interpreted to overlie the Dunvegan Formation at Site R3 and R4, which is known to be a regional aquitard where present (Riddell, 2012). However, at Sites R1, R2 and R5, it does not appear to be present in a continuous manner. Instead, the Dunvegan Formation frequently subcrops beneath Quaternary deposits, which are dominated by glacial till (Figure 13a, b and e) (Palmer, 2020). At Site R5 the Sully Formation is present at surface, while at Sites R1 and R2 it is present at depth below the Dunvegan Formation (Figure 13a, b and e). Based on current interpretations, the Sully Formation was too deep to be imaged at Site R3 and R4. The Sully Formation underlies the Dunvegan Formation and can be up to 300 m thick, but is generally 100-200 m thick (Stott, 1982; Jowett, 2004). The Sully Formation has been split into three units, the Upper Sully Formation, expected to be genetically linked to the Dunvegan Formation, the Fish Scale Member (FSM), related to an anoxic period within the CWIS that produced higher organic matter content and TOC, and the Lower Sully Formation, a concretionary marine shale (Jowett, 2004). While the Upper Sully Formation is expected to be hydraulically connected to the lower Dunvegan Formation (genetically related) to some degree, the FSM and Lower Sully Formation are marine shale-dominated units, which may provide protection from upward migration of deep contaminants. However, the Sully Formation has been found to be a fractured bedrock aquifer unit in portions of the Peace River Region (Lowen, 2011), making the study of the Sully Formations geologic and hydrogeologic characteristics at Site R5 of potential broader importance to better evaluate aquitard integrity. The presence of the Rocky and Mackenzie Mountains, Liard Line, Liard Thrust and Bovie Structure are all potential barriers or pathways affecting aquitard integrity in the region, making them important features when evaluating the integrity of aquitard units and groundwater flowpaths from recharge to discharge zones within this geometrically complex hydrogeologic system. 3.2.5 Fracture Network In bedrock aquifers, fracture networks generally control bulk groundwater flow (Parker et al., 2012). The limited core recovery from NWT01 suggests that the Dunvegan Formation contains poorly cemented and friable intervals (Figure 6). Seven intervals of core were recovered within the upper Dunvegan Formation, with recovery ranging in these intervals from 10-100%, averaging 46% on a 1.5 m core-run basis. Within the lower Dunvegan Formation core was recovered for all but the final run, with core recovery ranging from 46-104%, averaging 84%. Rock Quality Designation (RQD) measurements, which are associated with core recovery and indicate the competency of the bedrock, were collected for all core pieces greater than 10 cm in length (Figure 6). Only RQD measurements that were above 0% are the focus here, to aid in discerning the competency of bedrock where it was recovered. For the seven intervals of core recovered within

the upper Dunvegan Formation, RQD was 0% for four of the intervals and averaged 55% for the other three intervals, ranging from 49-64.6%. Within the lower Dunvegan Formation, the RQD was 0% for two intervals where core was recovered, with the remainder of RQD measurements between 32.8% and 86%, averaging 57.7%. This reaffirms that the upper Dunvegan Formation is more poorly consolidated than the lower Dunvegan Formation. It is important to consider the context of these core sections observed within the overall field program where there was considerable difficulty obtaining core and borehole stability throughout, hence the most competent sections of rock were likely retrieved, but perhaps with enhanced breakage. In the core that was recovered, a total of 26 fractures were documented in the upper Dunvegan Formation (Figure 6). Assuming the vertical borehole did not deviate significantly, eighteen fractures were horizontal with a dip of zero (69.2%), seven had shallow dips (<10 degrees) (26.9%), and one was a high-angle fracture at 70 degrees (3.9%), for a total of 5.3 fractures/m of recovered core. A total of 90 fractures were observed within the lower Dunvegan Formation, with fifty-seven (63.3%) of those fractures horizontal or dip of zero, eleven (12.2%) with shallow dip (5-30 degrees), and twenty-two (24.5%) were high angle fractures (50-90 degrees), for a total of 10.2 fractures/m of recovered core. Considering the poor recovery, RQD and fracture statistics, it is reasonable to assume that the upper and lower Dunvegan Formation would support groundwater storage and flow. The fracture frequency is relatively high for both the upper and lower Dunvegan Formation, indicating potential for significant effective (advective) fracture porosity and hydraulic conductivity. Bedding measurements from past mapping studies (Douglas & Norris, 1976) show that the Dunvegan Formation in this area is gently folded and dips shallowly (generally between 0-10 degrees on either limb of folds), suggesting that the majority of the fractures observed within NWT01 are likely bedding plane fractures, whereas high-angle fractures likely relate to joint sets. It is important to note that fracture frequency measurements from the core feature log are typically biased high due to the potential inclusion of mechanical breaks in the core created either through the drilling or core handling process. Additionally, there is bias in measuring fractures within vertical boreholes, where high-angle fractures or joints are systematically underrepresented (Terzaghi, 1965). While core recovery was not ideal, insights from the rock core suggest reasonable potential of the Dunvegan Formation to serve as a productive aquifer. This is supported by the relatively high fracture frequency and the apparent poor cementation of the matrix, which could allow productive groundwater flow. Groundwater movement in the upper and lower Dunvegan Formation are likely to be dominated by flow along bedding plane fractures, with the lower Dunvegan Formation having a higher probability of vertical flow along joints, based on a higher percentage of high-angle fractures in NWT01 core. 3.2.6 Physical and Hydraulic Properties of the Dunvegan Formation Physical property samples were collected from seven different sections of the recovered core (Table 3). Four samples were collected within the conglomerate-dominated upper Dunvegan Formation (7-40 mbgs) and three samples were collected within the sandstone-dominated lower Dunvegan Formation (40-50 mbgs). Matrix porosity values ranged from 18.6 to 22.9% in the upper Dunvegan Formation and 16.3 to 21.4% in the lower Dunvegan Formation. The Total Organic

Carbon (TOC) values ranged from <0.01 to 0.09% in the upper Dunvegan samples and <0.01 to 0.29% in the lower Dunvegan samples. Vertical hydraulic conductivity (K) of the rock matrix ranged from 1.11x10-6 m/s to 5.5510-8 m/s in the upper Dunvegan, and from 1.1710-10 m/s to 3.9610-11 m/s in the lower Dunvegan. These K values are within the expected range for sedimentary bedrock (Freeze & Cherry, 1979). These porosity and K measurements correspond to samples in which the rock matrix was well cemented, neglecting the contribution of fractures on storage and flow, and thus, the bulk parameters of the aquifer could be significantly higher than these lab-measured values, which will be explored in future studies (Parker et al., 2012). Extrapolation from the small-scale lab measurements to a larger scale was aided by the ERT survey data of the Dunvegan Formation at the five different sites. The ERT survey at Site R1 provided estimates of unit thickness, with the upper Dunvegan Formation being approximately 33 m thick and the lower Dunvegan Formation being approximately 60 m thick. These surveys provide a sense of the potential aquifer unit thicknesses, especially when average matrix porosity and average matrix vertical hydraulic conductivity values are considered for the upper Dunvegan Formation, 20% and 1.5910-6 m/s, and lower Dunvegan Formation, 18.8% and 1.1710-10 m/s, respectively. Hayes (2013) compiled porosity and K values for the Dunvegan Formation from three wells in northeast BC. The first well, B-071-K/094-O-06 included 43 samples between 111-126.8 mbgs with a maximum vertical K from laboratory measurements of 2.0010-5 m/s, an average K of 1.9810-6 m/s and an average porosity of 17.46%, representing unfractured “matrix” values. Based on a visual inspection of the core from C-066-L/094-O-09 & A-077-D/094-O-11 in this same study, K and porosity for each well were estimated to be between 1.00 10-8 m/s to 5.0010-7 m/s and 14% to 20%, respectively. These values are consistent with samples obtained from the upper Dunvegan Formation at NWT01, suggesting that similar K and porosity ranges are present throughout the basin, but do not represent the influence of fractures on flow variability and properties. 3.2.7 Porewater Hydrochemistry Porewater major ion samples collected from the 22 core samples at NWT01 reveal variable concentrations of two or more orders of magnitude for all the analytes but the major ion peaks include bromide, nitrate, phosphate, sodium, potassium and magnesium (Figure 14). The sparse nature of the samples collected does not allow for specific trend analysis with depth or by constituent but does allow for general variability to be discussed. Broadly, variation across several orders of magnitude was seen for all elements analysed, indicating a range of conditions exist in - - - - the subsurface. Anions (F , Cl , Br and NO3 ) are elevated within the shallower depths, whereas cations (Na+, K+, Ca2+ and Mg2+) are elevated within the deeper depths. Given the borehole’s proximity to a municipal waste facility, it is possible that some of these shallow major ion peaks, which lie just below the Quaternary sediments-bedrock interface, are associated with anthropogenic contamination. The deeper peaks in ion concentration could also relate to drilling additives. Drilling conditions (borehole stability and fluid circulation/return) deteriorated deeper in the hole, which necessitated the use of drilling additives (Bentonite, Sand Fix, EZ PAK, XANBORE) in order to stabilize the borehole. Future analysis of shallow groundwater quality at the waste site and the interaction of the drilling fluids with formation water is necessary to

determine if the presence of the municipal waste facility and the drilling fluids are associated with these major ion peaks. 3.3 Proposed Monitoring Well Network A 3D conceptualization of the Dunvegan Formation within the Fort Liard region was achieved using a combination of downhole stratigraphic, gamma logs and historical core and outcrop data, together with ERT measurements at strategic locations. These data will support the development of a future groundwater monitoring network for assessing current and future groundwater conditions. Future drilling activities, planned for Spring 2022 (See Appendix J for additional detail on this planned work), will focus on Sites R1, R2 and R5 (Figure 5; Figure 13), given the shallow presence of the Dunvegan Formation and underlying Sully Formation, which will allow detailed study across stratigraphic units, such as the Dunvegan as an aquifer unit and the Sully Formation as its underlying aquitard. The three sites aligned along a cross-section will show variability at increasing distances from the Bovie Structure and the depth and thickness of the Dunvegan away from this depositional and likely hydrogeologic boundary. Groundwater monitoring infrastructure at these sites will allow for monitoring of the Dunvegan Formation, and its underlying regional aquitard the Sully Formation, at its northern-most extent near the community of Fort Liard and will provide necessary data to establish baseline conditions for groundwater quality and flow system dynamics. Based on the results of this study, monitoring locations will consist of paired boreholes as illustrated in Figure 15. One borehole is to be instrumented with a high-resolution WestbayTM MLS equipped with 30-40 monitoring and/or sampling ports, permitting highest-resolution, depth- discrete hydraulic head and groundwater sampling at targeted sampling intervals using commercially available engineered multi-level systems well-suited for deep applications. The second borehole shall be equipped with a modified fibre-optic cable with heating cable to allow temperature monitoring with an Active, Distributed Temperature Sensor (A-DTS), co-deployed with a custom RSTTM transducer string comprised of 36 individual transducers with several thermistors to complement the A-DTS data (See Appendix K for DTS data from NWT01). These sensors will be permanently grouted in place. The fibre optic cable will allow continuous depth- discrete temperature monitoring along the full length of the borehole to identify natural variations in temperature through a Distributed Temperature Sensor (DTS), as well as periodic Active Distributed Temperature Sensing tests activated and monitored remotely using telemetry. The natural temperature variability can provide insight to seasonal changes and potentially groundwater recharge from precipitation events, and the A-DTS thermal testing can help identify and quantify the magnitude of hydraulically active flow pathways in the subsurface. Further information on DTS and A-DTS tools and techniques can be found in Coleman et al. (2015), Maldaner et al. (2019) and Munn et al. (2020). Both the DTS and transducer string will be connected to a telemetry system to allow remote access and backup of data. Paired boreholes allow instrumentation of compatible technologies in the same deployment configuration and complementary spatial and temporal resolutions. The three sites aim to show variability near and away from the large scale structures presumed to be of hydrogeologic significance. The three to five sites will enable collection of high-resolution, depth-discrete hydrochemical, isotopic, temperature and hydraulic data in space and time. This will provide continuous 3D monitoring of

shallow groundwater resources within a multi-depth, spatially variable hydrogeologic system with variable times of travel and responses to system changes from above and below. These datasets will establish a baseline to assess future impacts to water quantity and quality in the Fort Liard region. These few very high-resolution locations are required to characterize the system and identify HGU boundaries, with the idea that once the CSM has been informed by these high- resolution locations, systems with fewer ports can be designed to monitor specifically targeted zones at additional sites (R3, R4 and others), to better illustrate the character of the Dunvegan Formation at variable localities, at greater depths (>150 mbgs) and towards the intermediate zone and the freshwater-saline interface. Future field campaigns will adopt a revised drilling approach, using an LS600 sonic drill with the capability to complete rotosonic, air rotary and HQ3 diamond drilling to ensure more complete core recovery and borehole stability to a target depth of 149 mbgs, informed by the first field campaign at NWT01. Due to anticipated stability issues, permanent downhole monitoring systems are to be installed at the time of drilling and be designed on-site. 4.0 Conclusions A sequence stratigraphic framework of the Dunvegan Formation was extended to the north within the Liard Basin based on the integration of continuous core, borehole natural gamma and surface electrical resistivity tomography (ERT) measurements obtained near Fort Liard in combination with existing regional core and outcrop records. This study demonstrates the value of combining high-resolution multi-disciplinary datasets, from basin-scale (literature), to local-scale (ERT surveys), to site-specific-scale (continuous core and gamma logs) to develop a sequence stratigraphic framework for creating a future 3D groundwater monitoring network within the Fort Liard area. Updating the understanding of the Dunvegan Formation’s depositional conditions to its northern extent provides important insights regarding the source sediments and depositional conditions throughout its regional extent within the Western Canada Sedimentary Basin, and also provides an updated geologic framework for this regionally important aquifer located in a transboundary region of the Liard Basin and beyond in Alberta and British Columbia. The following key insights were made: 1. Borehole data, along with re-examined historical data allowed for the identification and delineation of an upper and lower Dunvegan Formation for the first time ever; with the upper Dunvegan Formation being coarse-grained and conglomerate dominated; and the lower Dunvegan Formation being fine-grained, and sandstone dominated. 2. Sedimentary features within upper Dunvegan Formation core (cross-beds, migrating barforms, imbrication) point to fluvial channel deposits, whereas sedimentary features within the lower Dunvegan Formation (climbing ripples, channel bank collapse features, crevasse splay, levee deposits) indicate distributary channels, contrasting with Stott’s (1982) postulation that alluvial fans dominated the northern Dunvegan Formation. 3. Paleochannel estimates suggest channel depths of 5.5-13.5 m for the upper Dunvegan Formation and 4.6-6.0 m for the lower Dunvegan Formation.

4. The upper Dunvegan Formation has a high percentage (80%) of conglomerate and sandstone (83% and 17%, respectively), while the lower Dunvegan Formation has a moderate percentage (53%) of conglomerate and sandstone (14% and 86%, respectively). 5. Based on re-interpretation of historical data, a lack of downstream fining or compositional sorting is seen in the Liard Basin’s upper Dunvegan Formation, indicating that the transition from a gravel-dominated to a sand-dominated depositional regime occurs outside of the Liard Basin, further to the southeast in BC and AB. 6. ERT data shows variability in the presence, depth, and character of the Dunvegan Formation at five study locations across the approximate 1200 km2 area referred to here as the Fort Liard region. Sites R1 and R2 depict the upper and lower Dunvegan Formation, further corroborating this delineation. ERT data was unable to delineate internal channel geometries within the upper or lower Dunvegan Formation. Sites R3 and R4 are believed to delineate the Dunvegan Formation being at depths greater than 150 m, illustrating spatial variability. Additionally, site R5 is interpreted to depict the underlying Sully Formation at surface, providing an opportunity to study this lithostratigraphically defined, regional aquitard unit in detail. 7. The upper Dunvegan Formation exhibited 5.3 fractures/m and is dominated by bedding plane fractures (69.2%) in the 5 metres of recovered core from 7 to 40 mbgs. The lower Dunvegan Formation exhibited 10.2 fractures/m and contained both bedding plane fractures (63.3%) and high-angle fractures (24.5%) in the 8.9 metres of recovered core from 40 to 50 mbgs. 8. The upper Dunvegan Formation exhibited an average matrix porosity of 20% and an average matrix vertical hydraulic conductivity of 1.59x10-6 m/s based on four samples collected between 26 and 35 mbgs. The lower Dunvegan Formation exhibited an average matrix porosity of 18.8% and an average matrix vertical hydraulic conductivity of 1.17x10- 10 m/s based on three samples collected between 41 and 49 mbgs. The above data allowed for the creation of a preliminary lithostratigraphic and sequence stratigraphic model for the Dunvegan Formation within the Liard Basin. The proposed lithostratigraphic model, constructed mainly through re-examination of historical data, delineated an upper and lower Dunvegan Formation separated by a middle shale layer. This middle shale layer extended across the Liard Basin, potentially acting as a continuous aquitard unit. Upon building on this lithostratigraphic model through incorporating newly collected data to create a sequence stratigraphic model, this continuous middle shale layer was found to be unlikely. Instead, the middle shale layer is interpreted to represent a series of dipping shale beds that are part of the lower Dunvegan Formation, allowing for hydraulic connection between the upper and lower Dunvegan Formation. This demonstrates the importance of applying sequence stratigraphy in hydrogeological conceptual model development rather than relying on existing lithostratigraphic frameworks, which would have resulted in a fundamentally different interpretation of the groundwater flow system, and will be enhanced with further investigations. The approach in this study, integrating multiple scales of data to create an updated geologic framework incorporating sequence stratigraphic principles to inform a future process-based hydrogeologic CSM, is proposed for the Dunvegan Formation showing facies-informed variability within a transboundary region of the Liard Basin. Hydrologic calibration of this geologic framework using hydrogeologic characterization and monitoring methods will provide essential data for the future hydrogeologic CSM. Enhanced understanding of the groundwater flow system

behaviour, both quantitatively and qualitatively, can be obtained through utilizing this approach. This should be followed with confirmation of hydrogeologic system boundaries and parameters essential to the prediction of flow system conditions and improved monitoring. This interdisciplinary approach for constructing a robust monitoring network allows for effective baseline groundwater monitoring and provides an improved basis for assessing impacts to groundwater from a variety of anthropogenic activities including past and future O&G operations, with these insights transferable globally to other O&G-rich sedimentary basins. State of the technology groundwater monitoring networks are an important element for sustainably managing freshwater resources vital to all, including remote northern communities in Canada.

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Table 1: Summary of channel geometry and variability within the Dunvegan Formation

Deposit Paleochannel Dunvegan depositional Sandstone/S Paleochannel Paleochannel Source Dataset Locality Avg. grain size thickness belt/valley width character hale ratio Depth (m) Width (m) (m) (km) Upper Dunvegan - This Study NWT01/ERT Fort Liard granule to pebble 33 100/0 5.5-13.5 - - fluvial Lower Dunvegan - This Study NWT01/ERT Fort Liard fine to medium sand 60 82/18 4.6-6 - - distributary channels Stott, 1982; Upper Dunvegan - This Study Liard Basin granule to pebble avg. 111.7 80/20 ~3-20 - - Hayes, 2013 fluvial Stott, 1982; Lower Dunvegan - This Study Liard Basin fine to medium sand avg. 54.1 53/47 - - - Hayes, 2013 deltaic Plint & Outcrop & Dunvegan - incised max 41, valleys: avg. 1-2, Wadsworth, Peace Region fine to medium sand - <3-10, max 28 ~100-150 well logs valleys mean 21 up to 8 2003 channels: 5- McCarthy et Outcrop & Dunvegan - incised Peace Region fine to medium sand 130 - 10, max 15, 10s-100 valleys: 0.5-4 al, 1999 well logs valleys valley: 35 Lin & Dunvegan - deltaic Bhattacharya, Well logs trunk streams Peace Region fine to medium sand - - 10-15 150-230 valleys: 0.5-2 2017 (allomember E) Dunvegan - deltaic tributary: up Bhattacharya Outcrop & tributary: 150, generally trunk streams Peace Region fine to medium sand - - to 16, trunk: et al., 2016 well logs trunk: 200

Table 2: ERT survey details.

Site Location Survey Line Length Latitude of Survey Longitude of Survey Line (m) Line Centre Centre R1 950 60°09’56.9362” N 123°15’56.6230” W R2 950 60°04’22.8630” N 123°02’52.9306” W R3 950 60°01’28.1568” N 123°15’56.6230” W R4 950 60°11’24.6592” N 123°39’48.6500” W R5 950 60°13’08.1552” N 123°22’23.6778” W

Table 3: Summary of physical property samples from the Dunvegan Formation at NWT01.

Physical Property Samples Bottom Top Depth Depth Length Wet density dry density Specific Vertical Hydraulic TOC Dominant Number (mbgs) (mbgs) (m) (g/cm3) (g/cm3) Gravity Conductivity (m/s) Porosity (%) Lithology Core Photo

NWT01- 26.08 26.21 0.13 2.225 2.14 2.64 1.26E-06 0.189 0.02 Conglomerate PP-001

NWT01- 26.965 27.1 0.135 2.2345 2.035 2.64 5.55E-08 0.229 0.02 Sandstone PP-002

NWT01- 33.92 34.05 0.13 2.316 2.149 2.64 1.11E-06 0.186 0.09 Conglomerate PP-003

NWT01- 34.4 34.52 0.12 2.239 2.119 2.64 3.92E-06 0.198 <0.01 Conglomerate PP-004

NWT01- 41.62 41.75 0.13 2.2885 2.1035 2.68 1.75E-10 0.214 0.29 Shale PP-005

NWT01- 43.34 43.475 0.135 2.384 2.2445 2.68 3.96E-11 0.163 <0.01 Shale PP-006

NWT01- 48.665 48.82 0.155 2.2435 2.1565 2.65 1.17E-10 0.1865 0.12 Sandstone PP-007

Figure 1: Basin scale schematic Schematic depicting the relevant basins of interest with respect to the Dunvegan Formation, which is present throughout parts of the Western Canada Sedimentary Basin, the Liard Basin and the Liard River Watershed. The extent of the Dunvegan Formation within the Liard Basin is shown, as is the Fort Liard Region, which is the study site. Approximate area, length along the longest axis and orthogonal width ranges are provided. The Liard River Watershed lies partially within the WCSB, but also includes headwater regions within the Mackenzie and Rocky Mountains that are northwest and west of the WCSB and lie outside its boundaries. The Liard River watershed funnels surface water into the Liard Basin and from there flows northwards (adapted from Bhattacharya & Walker, 1991a,b; Bhattacharya, 1994; Plint, 2000; Plint et al., 2001; Hay & Plint, 2009; Grasby et al., 2016; NEB et al., 2016; VanGulck, 2016).

Figure 2: Basins of relevance - Dunvegan Formation Maps detailing the different scales and basins of relevance to this study (adapted from Leckie et al., 1991; Bhattacharya & Walker, 1991a,b; Bhattacharya, 1994; Plint, 2000; Plint et al., 2001; Walsh, 2004; Hay & Plint, 2009; Grasby et al., 2016; NEB et al., 2016): a) The Dunvegan Formation was deposited within and is present within the WCSB and the Liard Basin. The Dunvegan Formation is presently located within parts of NWT, YT, BC and AB, either outcropping, subcropping or at depth. The area of previous study is delineated by the box, with the BC portion being part of the Peace River Region and the AB portion being part of western AB; b) Historical information on the Dunvegan Formation from within the Liard Basin was collected and re-interpreted to better depict the depositional environment and thus, the groundwater flow system. The Liard Line, the Liard Thrust and the Bovie Structure, are the major structural features present within the region.

Figure 3: Paleogeographic map of North America (Cenomanian Age) Paleogeographic depiction of North America during the Cenomanian, outlining the CWIS and the Dunvegan Formation, with deltaic deposits shown in yellow and terrestrial deposits (light pink) with their tributary streams (blue). Note that the most northern source area is within YT and NWT, proximal to the study area (from Bhattacharya et al., 2016).

Figure 4: Liard Basin lithostratigraphic cross section Cross-section of the Liard Basin, with the Exshaw marker indicating the location of the Exshaw- Patry shale, the major gas bearing unit within the Liard basin. To the east of the Bovie Fault Zone is the Horn River Basin, while the Liard Basin lies to the west with a large structural drop being present, which alters the formation thicknesses considerably. This figure cuts off the top portion of the Cretaceous, but it should be noted that the Dunvegan Formation does extend beyond the Liard Basin. The Dunvegan Formation is typically depicted as a shallow bedrock unit of similar thickness and lacking heterogeneity within the region. Previously discovered gas shows and pools are represented by a pink star. The Maxhamish Field, which is a producing field in northeast BC is also marked on the figure. (from Morrow & Shinduke, 2003).

Figure 5: Fort Liard region map

Map outlining the Fort Liard region (the study area), with relevant faults and geologic features shown, along with ERT survey locations and boreholes NWT0-A and NWT01 (adapted from Douglas & Norris, 1976).

Figure 6: NWT01 borehole datasets Data montage showing lithostratigraphy, sedimentology, natural gamma, recovery, Rock Quality Designation (RQD), fracture and sample location data collected from borehole NWT01. The stratigraphic log depicts a variety of depositional features outlined in Figure 6; “lp” indicates that the recovered core consisted of loose pebbles. The trends in the gamma log discussed in the text are marked 1-2 for the lower Dunvegan Formation and 1-4 for the upper Dunvegan Formation.

Figure 7: Stratigraphic features in NWT01 core Arrows point to the features described: A) represents a conglomeratic sequence with stacked bar- scale cross bed deposits with beds demarcated by varied clast size (6.35 cm x 28 cm photo from core interval 33.89-34.17 mbgs); B) represents a conglomeratic sample with a bedding plane visible (5 cm x 7 cm photo from core interval 36.03-36.18 mbgs); C) shows soft-sediment deformation features such as ball and pillow and slump features (5 cm x 7 cm photo from core interval 40.87-41.05 mbgs); D) depicts several preserved root structures (5 cm x 7 cm photo from core interval 45.93-46.06 mbgs); E) shows a preserved channel bank feature on the right hand- side, with the collapsed bank preserved on the left as a deformed feature (5 cm x 7 cm photo from core interval 47.15-47.27 mbgs); F) illustrates a series of climbing ripples (5 cm x 7 cm photo from core interval 47.41-47.84 mbgs); G) details tilted beds within sandstone (2.5 cm x 4 cm photo from core interval 49.89-49.97 mbgs).

Figure 8: Stratigraphic logs created from Stott’s outcrop descriptions After stratigraphic log creation, all logs were arranged from north to south and aligned with the Sully Formation used as a datum. This allowed for initial correlations between major lithologic units to be made and formed the basis for the delineation of an upper and lower Dunvegan Formation. Individual logs are detailed in Appendix G.

Figure 9: Conceptual models of the Dunvegan Formation within the Liard Basin The location of the cross-sections in map view are shown in Figure 2: A) Stratigraphic cross section (B – B’) of the Dunvegan Formation (updated from Stott, 1982) based on outcrop descriptions along river channel cliff faces. This model illustrates a chaotic alluvial fan-dominated deposit; B) Lithostratigraphic cross-section (C – C’) created based on stratigraphic logs from historical subsurface and outcrop datasets (Stott, 1982; Hayes, 2013). This model depicts an upper and lower Dunvegan Formation, separated by a middle shale layer; C) Sequence stratigraphic cross-section (D – D’) created for this study, based on a sequence stratigraphic framework informed by NWT01 core and gamma logs.

Figure 10: N-S Dunvegan Formation profile Both A and B are along the same transect outlined in Figure 2 and shown in the inset of B. The two cross sections are of the same scale and are both oriented NW-SE; A) Architectural schematic of the Dunvegan Formation during deposition in the Cenomanian (updated and modified from Bhattacharya, 1994; Plint, 1996; 2000; Hay & Plint, 2009) illustrating the variability in depositional mechanics and features with time (a vertical profile at any point) and geographical location (a horizontal profile at any point) across its length; B) North-south profile of the Dunvegan Formation (adapted from Bhattacharya, 1994; Hayes, 2013) in present time, illustrating the depth and thickness of the Dunvegan Formation within the WCSB. The northern extent of the Formation is conglomerate dominated but becomes more sandstone dominated to the southeast. The cross section in B of the Dunvegan Formation from NW to SE illustrates the fluvial and deltaic deposits known throughout the basin today, augmented by the depositional environment understanding presented in (A). Channel deposits in (A) are not to scale, but instead show channel fill material, abundance, and variability.

Figure 11: 3D conceptual model of the upper and lower Dunvegan Formation within the Fort Liard Region. Conceptual model of the upper and lower Dunvegan Formations within a paleo-channel belt in the Fort Liard Region. The model orientation is based on ERT section R1. The left face (NW-SE) shows prograding clinoforms associated with deltaic deposition, which are overlain by elongated preserved channel structures associated with the fluvial system. The front face (W-E) illustrates stacked layers of clinoform structures overlain by stacked channel deposits. The plan view (top face) illustrates the migrating and intertwined nature of the fluvial channels.

Figure 12: NWT01 stratigraphic log and gamma log overlaid on Site R1 ERT section. ERT line R1 with the stratigraphic and natural gamma log from NWT01. The upper section of the Dunvegan Formation, marked by a low gamma count and poor core recovery, corresponds to a high resistivity layer (red). The lower section of the Dunvegan Formation, marked by high gamma count and better core recovery, corresponds to a moderate to low resistivity zone (orange to light blue). The high resistivity zone is interpreted to be the upper Dunvegan Formation, whereas the gradual change in resistivity with depth within the lower section of the Dunvegan Formation could indicate an increase in shale or clay-rich minerals with increasing depth, likely representative of the lower Dunvegan Formation. 53

Figure 13: Processed ERT dipole-dipole survey sections ERT dipole-dipole surveys completed within the Fort Liard area and their interpreted results. A represents R1; B represents R2; C represents R3; D represents R4 and; E represents R5. Cross section lines are shown in Figure 4.

Figure 14: Major ion results Schoeller plot of major ion results, with major ions on the x-axis and concentration (mg/L) on the y-axis. The graph plots different constituents with depth, with shallower datapoints having a lighter colour and deeper datapoints having darker colours.

Figure 15: Schematic of paired boreholes Schematic detailing the paired boreholes which are planned to be installed at 3-5 sites within the Fort Laird region to aid in the creation of a 3D high-resolution baseline groundwater monitoring network.

Appendix A: Additional Background Literature Review

Table of Contents List of Tables ...... 58 List of Figures ...... 58 Background ...... 59 Scales of Relevance ...... 59 The Western Canada Sedimentary Basin ...... 59 The Liard Basin ...... 60 Depositional History of the Liard Basin ...... 62 The Dunvegan Formation ...... 63 The Sully Formation ...... 65 The Kotaneelee Formation ...... 66 Fluvial Morphology ...... 66 Hydrogeologic Knowledge of the Dunvegan Formation ...... 67 Local Groundwater...... 68 Community Wells ...... 68 Solid Waste and Sewage Lagoon Facilities...... 69 Oil and Gas Exploration in the Liard Basin ...... 71 Exploration History and Knowledge ...... 71 Dunvegan Formation and Oil and Gas ...... 72 Knowledge Gaps...... 72 References ...... 73

List of Tables Table A1: Liard and Petitot Rivers and Fort Liard Community Wells water quality...... 78 Table A2: Fort Liard raw water quality results...... 78

List of Figures Figure A1: Basins of relevance with respect to the Dunvegan Formation ...... 79 Figure A2: Map of the Dunvegan Formation and study sites around Fort Liard ...... 80 Figure A3: Liard Basin map with associated datasets collected...... 81 Figure A4: Late Albian paleogeographic map ...... 82 Figure A5: Middle Cenomanian paleogeographic map...... 83 Figure A6: Late Cenomanian paleogeographic map ...... 84 Figure A7: Early Turonian paleogeographic map ...... 85 Figure A8: Cross section showing the Pre-Devonian to Cretaceous units within the Liard Basin ...... 86 Figure A9: Development of the Bovie Structure through time ...... 87 Figure A10: Paleogeographic map detailing depositional environments of the Dunvegan Formation ..... 88 Figure A11: Paleogeographic map detailing the major lithologies of the Dunvegan Formation ...... 89 Figure A12: Cross section illustrating a typical lithostratigraphic depiction of the Dunvegan Formation . 90 Figure A13: Cross section detailing the heterogeneity within the Dunvegan Formation ...... 91 Figure A14: Dunvegan allomembers within the Peace River Region ...... 92 Figure A15: Schematic depicting main features of a Dunvegan Formation fluvial-dominated valley fill ... 93 Figure A16: Depositional morphology preservation as a function of aggradation, migration and avulsion ...... 94 Figure A17: Discontinuous Dunvegan Formation aquifers within the Peace River Region ...... 95 Figure A18: Mackenzie River Watersheds permafrost locations...... 96 Figure A19: Liard River to potential drill sites...... 97 Figure A20: Fort Liard community wells in relation to Liard and Petitot Rivers...... 98 Figure A21: Liard and Petitot Rivers confluence...... 99 Figure A22: Monitoring well locations within the municipal waste facility...... 100 Figure A23: Bedrock geology map with gas fields shown...... 101 Figure A24. Geology of eight selected gas fields in northeastern British Columbia ...... 102

Background Scales of Relevance This study focuses on the Dunvegan Formation, which is present at surface and within the subsurface across a large portion of the Western Canada Sedimentary Basin. The Western Canada Sedimentary Basin covers much of Western Canada and is host to some of the largest oil and gas deposits in Canada and the World (NEB et al., 2016). The Dunvegan Formation was deposited as part of a large deltaic complex during the Cenomanian age of the Cretaceous period (Bhattacharya, 1989). The Dunvegan Formation has been studied in detail within the Peace River Region, but little is known about the northernmost reaches of the formation, located within the Liard Basin, which is the focus of this study (Figure A1). As the Liard Basin crosses the borders of BC, YT and NWT, the aquifers within the basin are considered transboundary aquifers, increasing the complexity of potential contaminant mitigation and source water protection plans. This study looks at data of various scales, focusing on specific sites within the Northwest Territories portion of the Liard Basin, near to the Hamlet of Fort Liard (Figure A2), with the aim of understanding the geologic and hydrogeologic characteristics of the Dunvegan Formation within this region. With this in mind, data has been acquired from across the Liard Basin in the form of existing lithology and well logs (Figure A3). These various data points allowed a more basin-scale interpretation of the Dunvegan Formation geology and hydrogeology to be conceptualized, with the aim to add context and scale to the more localized sites in the NWT. Given that the majority of existing research was conducted within the larger Western Canada Sedimentary Basin, and more specifically within the Peace River Region, datasets from this area are used as comparative tools to better evaluate the Dunvegan Formation within the Liard Basin and determine how the Dunvegan Formation evolved from its northwesterly source area in the Liard Basin to its southeasterly sink area in the Peace River Region. All of these different levels of data are brought together to create a more robust model of the Dunvegan Formation across scales, from the localized sites in the NWT (Figure A2), to the larger Liard Basin (Figure A3) and even to the entire depositional system that lies within the Western Canada Sedimentary Basin (Figure A1). The Western Canada Sedimentary Basin The Western Canada Foreland Basin (WCFB), which is a part of the larger Western Canada Sedimentary Basin (WCSB) and within which the Liard Basin lies, was formed during the mid- Jurassic, due to the onset of oceanic lithosphere being subducted beneath the western edge of North America. This was a response to seafloor spreading in the Central Atlantic and caused exotic terranes to be accreted to the North American continental margin during the Jurassic and Cretaceous. This produced a major crustal shortening event, punctuated by compression and the development of a fold and thrust belt that trended northeastwards (McMechan & Thompson, 1993; Price, 1994). A retro-arc foreland basin, several hundred kilometres wide, was created along the western margin of North America due to loading by this fold and thrust belt, accompanied by regional dynamic subsidence. This foreland basin trended eastward into a broad, shallow epeiric seaway, known as the Western Interior Seaway, which was approximately 1000 km wide and experienced comparably little subsidence in relation to this foreland basin (Mitrovica et al., 1989;

Price, 1994). The combination of this foreland basin and shallow epeiric seaway are what is termed the Western Canada Sedimentary Basin. Through the creation of this basin, which corresponded with the Columbian Orogeny (mid-Jurassic to early Cretaceous), older Paleozoic and Mesozoic sedimentary rocks were eroded from present day northeast BC and southeast YT and this sediment was deposited in the adjacent foreland basin and internal seaway (Bhattacharya, 1989; Hay & Plint, 2009). Some of these sediments formed the Dunvegan Formation. During the Cretaceous, an internal seaway, known as the Cretaceous Western Interior Seaway (CWIS) was formed as North America was progressively flooded by the southern Gulf of Mexico- Tethys and by the northern Boreal Ocean. These marine embayment’s merged into the Cretaceous Western Interior Seaway just before the Albian-Cenomanian boundary (96 Ma) (Figure A4), shortly before the deposition of the Dunvegan Formation, and continued to widen into the mid-Turonian (90 Ma) (Figure A5; Figure A6; Figure A7) (Williams & Stelck, 1975; Hay et al., 1993; Kauffman & Caldwell, 1993). The interior seaway is largely attributed to static and dynamic loading that occurred from the mid-Jurassic onwards, creating the Western Canada Foreland Basin (Plint & Wadsworth, 2003). However, eustatic rise is likely to have played a significant role as well, as Turonian sea level is estimated to have peaked at 180 m (Sahagian & Jones, 1993) to 300 m (McDonough & Cross, 1991) above present levels, largely due to accelerated plate-spreading (Kauffman & Caldwell, 1993). A relative sea-level rise at the Albian-Cenomanian boundary resulted in the deposition of marine shales across the basin, marking the start of the Greenhorn Cycle (Kuaffman & Caldwell, 1993). This sea-level rise was accompanied by the abovementioned deformation, which resulted in rapid subsidence, leading to a westward-thickening wedge of marine shale being deposited as part of the Shaftesbury Formation, analogous to the Sully Formation in the NWT portion of the Liard Basin. The Shaftesbury Formation coarsened upwards as the Dunvegan Delta started to prograde in the early- to mid-Cenomanian. However, while the fluvio-deltaic formation that underlay the Shaftesbury Formation had prograded to the northwest, the Dunvegan Formation prograded to the southeast, marking a major shift in the regional sediment dispersal direction. This shift marked the migration of the maximum Cordilleran uplift to the northwest, as a result of the accreted terranes along the western margin of North America (Eisbacher, 1982; Poulton, 1994). The Liard Basin The Liard Basin is in the very northern reaches of the Western Canada Sedimentary Basin and Western Canada Foreland Basin, just west of the Horn River Basin, another basin that contains significant natural gas reserves (Walsh et al., 2005; National Energy Board, 2016). The Liard Sedimentary Basin is an asymmetric north-trending structural trough that is ~80 km wide and ~200 km long (Figure A3) (Monahan, 2000). The Liard Basin was periodically inundated by an internal seaway, leading to variations in marine and clastic deposits based on a series of transgressive- regressive cycles. The Liard Basin is located just east of the Cordilleran Orogenic belt, largely within a region known as the Interior Platform. The western edge of the basin is roughly bounded by the Cordilleran Orogen extent (Monahan, 2000; VanGulck, 2016). The Liard Basin has over 5 km of sedimentation within the basin ranging from Cambrian to Upper Cretaceous in age, with minor Cambrian- Silurian deposition and a lack of any major Jurassic deposition (Figure A8) (Monahan, 2000; Walsh

60 et al., 2005; National Energy Board, 2016). Unconsolidated sediments overlie these lithified deposits with varying depths between 0-100 m (from studies in the Toad River Region to the southwest of Fort Liard in BC) (McMechan et al., 2012). Water well drilling and shot hole logs have helped ascertain an average depth to bedrock of 18 to 24 m below ground surface within the NWT portion of the Liard Basin (Van Praet, 1988; Smith, 2015). It should be noted that this depth to bedrock could be highly variable within a small spatial area due to the variable nature of overlying fluvial and glaciofluvial deposits. On the eastern extent of the basin, the Bovie Structure separates the Liard Basin from the adjacent Horn River Basin, although many of the geologic units are continuous between the two basins, including the Dunvegan Formation (Walsh et al., 2005 & National Energy Board, 2016). The Bovie Structure is proximal to the study site and is an important feature as it may influence the groundwater flow system in the area. The Bovie Structure has been found to have two stages of compression, with the first being a Late Carboniferous to Permian age westward convergent steeply dipping thrust fault. The second stage of compression was the Laramide-age Bovie Lake Thrust, which cut the first generation of faulting at its base and merged with the larger Bovie Fault Zone at shallow depth (Morrow and Shinduke, 2003; MacLean and Morrow, 2004). The first generation of Bovie faulting was formed by Permo-Carboniferous crustal uplift and compressional tectonics, whereas the second generation resulted from detachment faulting (Jowett et al., 2007). No strike-slip movement is apparent along the Bovie Fault (Figure A9) (Morrow and Shinduke, 2003). The shallower units are more likely to be continuous across the Bovie Structure, whereas the deeper and older units, mainly the Mississippian Debolt Formation through upper part of the Lower Cretaceous Garbutt Formation, are often truncated against the Bovie Structure. Structural elevation drops exist in excess of 1200 m from east to west across the Bovie Structure, with the greatest drops occurring in the older Devonian strata. These differences in fault block displacement and faulting activity have also led to vastly different formation thicknesses along the Bovie Structure. At the crest, this feature is anticlinal, with several gas pools having been found along this structure in the past, within the BC portion of the Liard Basin (Monahan, 2000). The west and northwest edges of the Liard Basin are bounded by the Liard Fold and Thrust belt and the west to southwest portion of the Liard is bounded by the Rocky Mountain Foothills (Walsh et al., 2005; Jowett et al., 2007). The west and northwestern edge of the basin transitions from the Rocky Mountain Belt into the Liard Plateau, also referred to as the Liard Fold and Thrust Belt (Figure A3) (Walsh et al., 2005; Jowett et al., 2007). The Liard Plateau is situated within the Cordilleran Structural Province where there is a notable change in structural regime, as the Rocky Mountains lie to the south and the Mackenzie Mountains lie to the north (Government of Yukon, 2001). Deformation within the Rocky Mountains is thought to have occurred through basal detachment faulting, in which the overlying strata detached from the crystalline basement rock, leaving it relatively undeformed (Government of Yukon, 2001). The Mackenzie Mountains structural regime consists mainly of high angle faults, often reverse, which are the result of basement fault blocks shifting vertically, creating varying dips from east to west (Government of Yukon, 2001). At the northern extent of the Rocky Mountains, around the 60° parallel, the northwesterly trend of the mountain range is shifted to the northeast, creating en-echelon offsetting of mountain blocks in an east-west right-hand fashion (Government of Yukon, 2001). These differing regimes create the diverse structural features and trends that are seen within the Liard Plateau. The Liard Line marks the transition in these structural regimes with a major bend having

61 occurred between the northern terminus of the Rocky Mountains which trends northwesterly to the more northerly Mackenzie Mountains. The Liard Line is a northeast-trending transfer fault zone that results from the pinch out of Ordovician to Devonian strata and has largely affected sedimentation and tectonics in the region (Cecil et al., 1997; Grasby et al., 2016). The most notable feature of the Liard Line is that it acts as the first-order division of the Canadian Cordilleran Miogeocline, with vastly differing depositional regimes northwest and southeast of the Liard Line (Cecil et al., 1997). Depositional History of the Liard Basin Throughout the Cambrian to Late Silurian, much of the Liard Basin underwent continuous subsidence and deposition due to the western miogeocline, where generally shallow water allowed for clastic sedimentation, which thickened seaward forming a clastic wedge along the passive margin that marked the edge of the basin (Government of Yukon, 2001). The Atlantic coast of North and South America are current examples of this phenomena. During the Late Silurian, a brief withdrawal of the sea occurred, likely due to the Caledonian Orogeny (Government of Yukon, 2001). This withdrawal is indicated by the lithologic change in the geologic record of the time. By Early Devonian time, transgression marked the return of the sea, which pushed eastwards and deposited carbonates and shales through to the Late Devonian without disturbance (Government of Yukon, 2001). Towards the end of the Late Devonian, uplift in the Toad River area of British Columbia may have pushed northwards towards the Beaver River/Beavercrow High area (Government of Yukon, 2001). This uplift enhanced the effect of the miogeocline, resulting in a thickened succession of carbonates and shale deposits within what is now the Yukon Territory (Government of Yukon, 2001). During the Carboniferous, thick shale deposits occurred throughout much of the western region of the Liard Basin, which were associated with sandstone and siltstone of Banffian age and carbonate rocks of Late Carboniferous age (Government of Yukon, 2001). Fluvial, deltaic and near shore sand, which was sourced from the northeast reaches of the Liard Basin, were deposited in large quantities within the northern portion of the Liard Basin during this time (Government of Yukon, 2001). From the Permian through the Early Triassic a shallow sea transgressed again, resulting in thin deposits of clastic sediments. This shallow sea regressed during the Late Triassic and Jurassic, which is why there is no significant stratigraphic record from this period (Figure A8) (Government of Yukon, 2001). Transgression occurred in the Cretaceous, which led to thick clastic deposits being laid down (Government of Yukon, 2001). Towards the end of the Late Cretaceous, uplift due to orogenic activity resulted in a succession of dipping faults, which are evident at surface in certain areas throughout the basin (Government of Yukon, 2001). This faulting episode generally occurred along the hinges of Early Paleozoic folds, with the dominant structural regime varying from the west (having east dipping faults), to the central portions of the basin (having gently folded antiforms with minimum faulting), and to the east (with predominantly west dipping fault systems) (Government of Yukon, 2001).

The Dunvegan Formation The Dunvegan Formation is a fluvial-deltaic deposit of Cenomanian age that was located on the western edge of the CWIS, with its headwaters within northeast BC and southwest NWT (Figure A10). The Dunvegan river system carried sediment sourced mainly from northeast BC and southeast Yukon, associated with tectonic collision and uplift, towards the CWIS. The Dunvegan Formation’s original extent covered parts of NWT, BC and Alberta (AB) and the Dunvegan Formation is still found discontinuously throughout these regions outcropping and within the subsurface (Figure A11). The Dunvegan Formation’s distal deltaic deposits have been studied in great detail within the Peace River Region in northeast BC and in western AB (Bhattacharya, 1989; 1994; Plint 2000; 2002; Plint & Wadsworth, 2003; Plint et al., 2012; McMechan, Ferri & Macdonald, 2012; Riddell, 2012). In contrast, very little is known about the Dunvegan Formation within the Fort Liard region (Stott, 1982; Riddell, 2012). When referenced, it is generally within a simplified lithostratigraphic context where the Dunvegan Formation is shown as a uniform band of equal thickness and lacking internal heterogeneity (Figure A12), or as a more detailed schematic that is not up to today’s sequence stratigraphic standards (Figure A13). Therefore, drilling activities near Fort Liard are providing a unique opportunity to study the Dunvegan Formation proximal to the source of the Dunvegan Delta, likely originating within or near to the Rocky and Mackenzie Mountains. The Fort Liard region is most likely within the proximal tributary portion of the Dunvegan Delta instead of within the distal or distributary portions of the Dunvegan Delta, where most research has been completed (Bhattacharya, 1994). The Dunvegan Formation is coarser grained near to Fort Liard, indicating the deposited sediment likely travelled shorter distances. It also indicates the presence of some controlling feature that would have caused this sediment to come out of bedload or suspension and be deposited within the fluvial channel, such as a change in slope along the fluvial channel, a change in basin dynamics that resulted in sediment trapping, or tectonic activity that may have created a barrier to larger grain sizes travelling farther downstream (Paola, Hellert & Angevinet, 1992; Paola & Seal, 1995; Bhattacharya et al., 2016). The Dunvegan Formation was deposited over ~2 million years. Within Fort St. John and the Peace River Region, preserved deposits are representative of the delta plain, delta front and prodelta and have been split into ten different allomembers (labelled A-J), broadly related to transgressive- regressive sequences (Figure A14) (Bhattacharya, 1994; Plint, 2000). The total formation within this area ranges from 90-270 m thick, with individual allomembers varying in thickness, having maximum thicknesses up to 80 m. Individual allomembers are composed of multiple shingles, or parasequences, that are expected to have taken 50-100 thousand years (ka) to deposit (Bhattacharya, 1989). The deltaic deposits downlap onto the Fish Scales Upper (FSU) marker, which has been delineated as the base of the Dunvegan Alloformation. The updip sandy portions of the deposits (delta front) are assigned to the Dunvegan Formation, whereas the downdip muddy portions of the deposits (prodelta) are attributed to the Shaftesbury Formation (Plint, 2000), which is analogous to the Sully Formation within this study area. A marine flooding surface above allomember A marks the top of the Dunvegan Alloformation and the transition to the overlying Kaskapau Formation (Plint, 2000), which is termed the Kotaneelee Formation within this study area. These deltaic deposits often have a composition of 50% sand, a much higher proportion than the muddier deposits of the Mississippi Delta (Bhattacharya, 1989). Within the different Dunvegan Formation allomembers, variable processes dominated, with some shingles and allomembers being wave-dominated, while others were river-dominated (Bhattacharya, 1989; 1991a, b). From allomember J to C, an overall progradational stacking pattern and associated regression are seen,

63 with the paleo-shoreline advancing seaward ~60 km with the deposition of each new allomember. For allomembers B to A, there was a roughly 220 km backstep, with deposits shifting landward (Hay & Plint, 2009). The older allomembers have been found to be deposited under periods of high sedimentation, whereas the younger allomembers were deposited under lower sedimentation regimes (Bhattacharya, 1989). Moving landward, delta plain deposits have been studied in detail within the Fort St. John region (McCarthy et al., 1999; Plint, 2002; Plint & Wadsworth, 2003; McCarthy & Plint, 2003). These deposits are generally represented by channel bodies encased in floodplain deposits. Bhattacharya (1989) found that some channels could be up to 18 m deep, with channel belts generally less than 5 km wide. Further research within the Fort St. John region, specifically through outcrop mapping of Dunvegan strata within canyons of the Kiskatinaw River within northeast BC, ~120 km inland of marine strata, have shown that incised valley systems are prevalent (McCarthy et al., 1999). These valleys can be 15-41 m deep, averaging 21.3 m deep and are generally 1-2 km wide, but can be up to 10 km wide, locally (Figure A15) (Plint, 2002; Plint & Wadsworth, 2003). The widest portions of these incised valleys sometimes are located at valley confluences, but not always (McCarthy et al., 1999). These incised valleys are often separated by 10-30 km with the main driving factor of their incision and formation expected to relate to eustasy (McCarthy et al., 1999; Plint, 2002). Within these valleys, the valley fill is dominated largely by fine-medium grained sand (up to 97%), which represent multi-storey point bars (Plint, 2002). Two main types of channels have been preserved within these incised valleys. The first, interpreted as anastomosed channels, are small, single story, very fine-fine grained sandstone ribbons with width-to-thickness (W/T) ratios <30. These channels are hosted within fine-grained floodplain sediments. The second channel type, interpreted as meandering river channels, are represented by fine-medium grained sands, laterally accreting point-bar deposits, which form multi-storey sand bodies with individual bodies having W/T ratios >30 (McCarthy et al., 1999). One specific sand body found within McCarthy et al.’s (1999) study was a multi-storey sand body at least 35 m thick, 1 km wide, with a W/T ratio >30. The base of the sand body was scoured into the underlying sediments, with the overall sand body geometry showing 2 to 5 stories, separated by thin intraclast layers. Further to the west and north, the Dunvegan Formation is dominated by conglomeratic deposits interpreted by Stott (1982) to have been deposited in fluvial to piedmont alluvial environments, with the major mode of deposition being alluvial fans. This interpretation has not been updated since Stott’s original assessment. These conglomeratic deposits are confined to northeast BC and the NWT, with the majority of the sediment for these deposits being sourced from northeast BC and YT (Stott, 1982). Increased sedimentation likely relates to the Columbian Orogeny (mid- Jurassic to early Cretaceous), which would have allowed for increased weathering and erosion due to uplift throughout Dunvegan deposition (Bhattacharya, 1989). Further, subsidence in the Western Canada Foreland Basin continued throughout the Cenomanian, creating continued accommodation for the deposition of this sediment (Plint et al., 2012). This foreland basin would have had a hinge zone 50-100 km eastwards of the Cordilleran mountain front, which would have run roughly northwest-southeast along the mountain front (Bhattacharya, 1989). Research completed by Paola (1988) detailed an inverse relationship between the distance gravel travels and the subsidence rate, which was 0.19-0.26 m/1000 years (yrs) for the Western Canada Foreland Basin. The landward accumulation rate for the Dunvegan Formation, being between 0.15-0.3 m/1000 yrs, indicates that sedimentation rates were such that sediment accumulation could generally fill the accommodation created by subsidence (Bhattacharya, 1989). Paola (1988) showed that foreland basins with asymmetric subsidence tend to produce wedge-shaped units with

64 most of the gravel confined close to the source. Rapid downstream fining and deposition of thick tabular wedge-shaped conglomeratic bodies along the axis of greatest subsidence could be expected within these settings. Compositional sorting should also be seen with downstream distance. The Sully Formation The Sully Formation conformably underlies the Dunvegan Formation and is generally considered to be a regional aquitard (Riddell, 2012), although the Sully Formation is known to host some water wells within the Peace River region, where it is fractured and able to produce water (Lowen, 2011). The Sully Formation is marked as its own formation within northeast BC and NWT, however, further to the southeast in BC and AB, the Sully Formation is considered a part of the Shaftesbury Formation (Stott, 1982). The Sully Formation has been found to be up to 300 m thick towards the western edge of the Liard Basin, but is more commonly ~100-200 m thick throughout the rest of the Liard Basin and beyond (Stott, 1982; Jowett, 2004). The Sully Formation conformably overlies the Sikanni Formation, another fluvial-dominated deposit. The contact between the two formations is thought to be diachronous, becoming younger to the east (Stott, 1982). The main descriptions of the Sully Formation are from outcrop; where the Sully Formation is entirely exposed (Section 65-10 from Stott, 1982 – See Appendix F) it has been subdivided into three separate units. Stott (1982) deemed them the lower concretionary member (85 m thick), the middle flaky shale member (122 m thick) and the upper concretionary member (91 m thick); which were re-interpreted by Jowett (2004), as the lower concretionary member, the fish scales member (FSM) and the upper concretionary member. The lower concretionary member, or the Lower Sully Formation, directly overlies the Sikanni Formation. This transition is marked by a significant basal conglomerate facies, overlain by Lower Sully Formation shale, indicating a profound relative sea level fall followed by extensive flooding (Jowett, 2004). This basal conglomerate was present across all regional outcrops studied by Jowett (2004). The Lower Sully Formation exhibits relatively low total organic carbon (TOC) of ~1.0- 1.4 weight percent (wt.%) and a reduction in benthic foraminiferal faunas with respect to the Sikanni Formation, indicating environmental stresses such as brackish water and/or high turbidity (Jowett, 2004). The FSM is a laterally extensive marker, exhibited frequently by a bioclastic bed with an abundance of fish scales throughout much of the WCSB. Generally, it is relatively thin and condensed, being 1.5 m thick in the Peace River Region of AB, with increased TOC values (Jowett, 2004). Within the Liard Basin, Jowett (2004) stated that the FSM, instead of being a series of thin beds is rather a ~80-120 m thick fissile shale member, characterized by a reduction in benthic foraminifera, an increase in TOC (~1.4-2.8 wt.%), an increase in organic matter, an abundance of algal cysts and gypsum in outcrop, which is inferred to be related to pyrite weathering, linked to production of pyrite by sulphate-reducing bacteria under anoxic conditions. These conditions are similarly seen within the Shaftesbury Formation (Leckie et al., 1992) and help to indicate that at least in northeast BC and NWT anoxia persisted for a period of time. Deposits in the Cold Lake region overlying the Belle Fourche Formation above the FSM are also barren of foraminifera, suggesting this anoxia persisted in northeast AB as well (Jowett, 2004). The FSM is thought to downlap and pinch out to the southeast towards Fort St. John, indicating that the FSM in the Liard

Basin preserves a more continuous record of sedimentation than elsewhere, similar to the Shaftesbury of northwest Alberta as described by Bhattacharya & Walker (1991a, b). The upper concretionary member, or the Upper Sully Formation, gradually coarsens from shale to a more sandstone dominated deposit until it grades into the Dunvegan Formation. Sideritized beds are present within the Upper Sully and at outcrop scale appear impermeable to groundwater flow, creating seepage faces (Jowett, 2004). The Upper Sully has low TOC values and exhibits a gradual recovery of foraminifera, being fully recovered by the basal Dunvegan Formation. The Upper Sully Formation is considered to be genetically linked to the Dunvegan Formation and is expected to represent the advancing influence of the initial downlapping clinoforms of the Mid-Cenomanian Dunvegan Formation (Jowett, 2004). Based on this and foraminifera observed, it is expected that the Upper Sully and Basal Dunvegan Formation within the Liard Basin are older than their counterparts to the southeast. The Upper Sully represents the distal progradational deposits of the Dunvegan Formation, which eventually prograded ever-basinward, creating the deltaic deposits seen in the Peace River Region and studied in detail (Bhattacharya, 1994). The Kotaneelee Formation The Kotaneelee Formation overlies the Dunvegan Formation and is dominated by marine shale, being considered a regional aquitard (Riddell, 2012). The Kotaneelee Formation is 152-305 m thick and is the equivalent to the Puskwaskau Formation of the Deep Basin and eastern Fort St. John regions (Riddell, 2012). The Kotaneelee Formation is present at or near surface, underneath variable Quaternary deposits, within much of the Liard Basin (Figure A3) (Walsh, 2004). This formation potentially acts as a barrier to any downward migration of contaminants, although exposure at surface could have led to erosion and fracturing, allowing for downward migration of both groundwater and contaminants along fracture surfaces. Very little is known about the Kotaneelee Formation, as it has not been studied in detail through oil and gas or mapping studies to date. Fluvial Morphology When attempting to create a sound CSM, it is important to try and understand as much as possible about the basin, formation, or unit that you are focusing on, but it is also integral to consider the associated facies model and depositional environment that corresponds to this unit of interest, especially with respect to clastic sedimentary deposits. Without understanding the depositional system that created this deposit, creating a coherent CSM is almost impossible, as many different depositional processes can create similar lithologic features. Fluvial deposits, of which the Dunvegan Formation within the Liard Basin is, are especially difficult as no two rivers or river systems are alike, despite often being categorized as braided, meandering or anastomosing; so classic facies models or depositional model diagrams, while a helpful start, only go so far in helping to elucidate the presence of these features within the rock record (Figure A16) (Bristow & Best, 1993; Bridge & Tye, 2000). Furthermore, more recent research focusing on the empirical relationships that govern fluvial morphology has shown that it is generally more important to understand the aggradation, avulsion and migration rates of rivers, versus whether they are braided, meandering or anastomosed. This is due to the fact that these three features, the aggradation, avulsion and migration rate, dominate how a fluvial system will be preserved in the rock record

66 and what this system will look like (Bristow & Best, 1993). However, this is not an easy task. While aggradation rates may be obtained through other geologic studies, understanding the avulsion and migration rates of ancient fluvial systems is considerably more difficult, with current research ongoing to attempt to ascertain this information for present-day fluvial systems of varying form (Bhattacharya personal comm., 2020). With this in mind, and knowing that no CSM will accurately represent the complexity of a system, there are some empirical relationships associated with fluvial systems that can help to better construct a CSM that, while not representing the actual system accurately, can still provide a framework for conceptualizing the flow system and interpreting data that is grounded in empirical relationships derived from thousands of fluvial systems, both ancient and present. While these empirical studies frequently reference fluvial deposits as productive aquifers and state that these empirical studies are helpful to better understand and qualify groundwater systems (Bristow & Best, 1993; Bridge & Tye, 2000; Gibling, 2006), the level of detail provided by these studies that is utilized for petroleum reservoir characterization, geotechnical engineering and geomorphology is not frequently pursued in groundwater studies, where simplified lithostratigraphic concepts and static conceptual models still persist. Study of the fluvial portion of the Dunvegan Formation has shown that paleo-rivers generally were not deeper than 10-15 m, but have been seen to be as deep as 21 m, with widths generally not extending more than 100-150 m for individual channels or 10-15 km for channel belts (Lin & Bhattacharya, 2017; Bhattacharya personal comm., 2020). These empirical relationships based on outcrop and well log studies completed to date on the Dunvegan Formation are similar to those proposed by other researchers (Bristow & Best, 1993; Bridge & Tye, 2000; Gibling, 2006), helping to act as a helpful starting point for the creation of an empirically-informed CSM. Hydrogeologic Knowledge of the Dunvegan Formation Freshwater bedrock aquifers are found almost exclusively within Cretaceous strata in northeast BC and, of these Cretaceous bedrock units, the most important freshwater aquifers are the coarse clastic Cenomanian-aged Dunvegan Formation and the Campanian-aged Wapiti Formation (Riddell, 2012). The Upper Cretaceous Kotaneelee Formation, which conformably overlies the Dunvegan, is dominated by shale strata and generally behaves as a regional aquitard, separating these two aquifer-bearing formations (Riddell, 2012). Groundwater studies within the Dunvegan have been limited to general background research completed within the Peace River Region, near Fort St. John (Lowen, 2011), approximately 600 km south of Fort Liard. There it has been found that the highest capacity wells are within the Dunvegan Formation, with yields of up to 15.8 litres/second (L/s) (average of 0.6 L/s), with transmissivities ranging between 23-45 (metres squared/day (m2/d) and a storativity of 8.3x10-4 (Lowen, 2011). It is anticipated that the Dunvegan Formation will have high yields as it is a formation of non-marine origin that has both primary and secondary porosity (Lowen, 2011). Secondary porosity has been found in the form of fractures that, when present, dominate groundwater flow (Lowen, 2011; Riddell, 2012). However, it is stated that due to drainage systems and bedrock weathering and erosion, the aquifer has been segmented by channel features that make the aquifer discontinuous within the Peace River Region (Figure A17) (Cowen, 1998; Lowen, 2011; Riddell, 2012). It has also been found that the groundwater quality within the Dunvegan Formation is variable, being potable in only some regions and often described as hard (Lowen, 2011). The water quality within the Dunvegan Formation generally deteriorates

67 with depth below ground surface (Matthews, 1950; Riddell, 2012). It should be remembered that these studies were completed ~600 km south of the Liard study area and in a portion of the Dunvegan Formation that could differ largely in geologic character due to variable depositional environments. The surface water within the Liard Basin flows from YT and BC into the NWT. It is currently assumed that the regional groundwater flow systems will follow similar pathways, allowing upstream contamination from YT and BC to be carried into NWT through natural flow pathways (VanGulck, 2016). Surface water carrying contaminants from YT and BC could infiltrate into the subsurface within NWT and likewise contaminate the groundwater system. The flow system dynamics and the relation of surface water and groundwater within the Liard Basin needs to be further studied to ascertain this relationship and the associated risks. Local Groundwater The Hamlet of Fort Liard is one of the oldest continuously-occupied settlements within the NWT and sits on top of alluvial deposits that form a river terrace (Hoggan, 1985; Dillon Consulting Limited, 2003). Below the upper fluvial deposits, with thicknesses of one to several metres, there are underlying glaciofluvial deposits consisting of proglacial outwash, gravel and sand with minor diamicton. These deposits would have been laid down in front of the glacier margin and have thicknesses ranging between one and ten metres (Dillon Consulting Limited, 2003). Fort Liard lies within the sporadic discontinuous permafrost zone (Figure A18) (Hoggan, 1985; VanGulck, 2016), however, no permafrost has been encountered during water well drilling projects thus far (Hoggan, 1985; Van Praet, 1988). Within the NWT, no groundwater monitoring network exists currently and very few scientific studies concerning groundwater quality exist (VanGulck, 2016). This study will be the first of its kind in the region. Community Wells The population of Fort Liard was c. 408 in 1988 (Van Praet, 1988) and 500 in 2016 (Statistics Canada, 2017). Fort Liard’s drinking water is supplied by two wells on the bank of the Liard River proximal to the Petitot River junction. The wells are 200 mm in diameter and were installed with pumps capable of pumping 200 L/min (Van Praet, 1988). The first test well was drilled in 1989 at a distance of ~10 m from the Liard River bank to a depth of 18 mbgs, while the two production wells were drilled adjacent to the test well with depths of 15 and 18 mbgs (Figure A19; Figure A20) (Van Praet, 1988; Tam and Philip, 2002). Bedrock is generally assumed to be between 18 to 24 mbgs. During drilling, the upper 10 m was comprised of dry silt, sand and gravel with some large boulders. Saturated sand and gravel were encountered from 11 to 18 m, after which the sediments became significantly finer-grained with a large silt content. A stainless-steel well screen was installed from 16.7 mbgs to 18.2 mbgs which makes up the pumping interval. A slight smell of hydrogen sulphide (H2S) was noted during well development. Results of a 24-hour pumping test showed an average discharge rate of 279 L/min (4.65 L/s), with a total drawdown of 0.47 m. Recovery was 0.05 m within the first 16 minutes. From this, it was determined that this well could be pumped at a capacity in excess of 1,000 m3/day or 694 L/min (11.57 L/s) (Van Praet, 1988). It was determined that water levels within the well fluctuated with the river levels, based on water level measurements collected with time, indicating direct connection between the river and aquifer. The river provides recharge to the aquifer during periods of high river stage, while the aquifer discharges to the river, sustaining baseflow, during low stages (Figure A19) (Van Praet, 1988). Air photo analysis indicated that the Petitot River is likely the body of water that has the strongest

68 influence on water quality within the Liard wells (Figure A20; Figure A21) (Dillon Consulting Limited, 2003). This results from the wells being located at the confluence of the Petitot and Liard Rivers and the waters from the Liard and Petitot not having mixed completely prior to reaching the location of the community wells. It should be noted that the flow within the Liard River varies drastically throughout the year, with winter flow volumes ranging from 200-400 m3/s, while summer flow volumes range from 4000-8000 m3/s (Figure A19) (Barry et al., 1998). The winter flow is entirely contributed by groundwater (Barry et al., 1998). Given the wide variation in flow volume and the large suspended load carried by the river in spring and summer versus almost none in winter, there are wide variations in water chemistry and quality that vary cyclically (Barry et al., 1998). Overall, studies have shown that the Liard River is generally healthy and uncontaminated (Table A1) (Barry et al., 1998). A water treatment system is in place to remove iron, manganese, and hydrogen sulphide, and provide 0.5 to 0.75 mg/L residual chloride to water extracted from the groundwater wells (Van Praet, 1988). Water pumped from these wells is held in reservoir tanks and trucked to residents on a regular basis, as there are no underground or above ground pipes to carry water within the Hamlet of Fort Liard (Van Praet, 1988). Some shallow dug private wells do exist within the community. It was found that these shallower dug wells, which tap into the surface of the water table, have better water quality than the deeper test well that exhibited an H2S odour and had higher hardness and iron levels (Van Praet, 1988). Sewage disposal through pits and septic tank infiltration fields could present a risk to shallow groundwater quality. A water quality assessment of the two municipal pumping wells found that the supply water is very hard, very well buffered, slightly alkaline and high in dissolved solids (Table A1; Table A2) (Facey and Smith, 1991). An additional water quality review was conducted in 2002 and found the associated infrastructure was in excellent condition (Tam and Philip, 2002). However, water quality sampling indicated exceedance of the Guidelines for Canadian Drinking Water Quality (GCDWQ) for iron (0.3 mg/L) and manganese (0.12 mg/L). Additionally, the hardness concentration in the raw water exceeded 300 mg/L, whereas hardness values greater than 200 mg/L are considered poor under the GCDWQ (Tam and Philip, 2002). Water quality summaries from sampling campaigns conducted in 1983- 1984 and 1999-2003 are shown in Table A1 and Table A2, respectively, with the 1983-1984 water quality results also showing comparative results from the Liard and Petitot Rivers (Dillon Consulting Limited, 2003). It should be noted that because the community wells are hydrologically-connected to the Liard and Petitot Rivers, the wells’ water chemistry and quality might not be indicative of regional groundwater chemistry and quality as a whole (Figure A19) (Barry et al., 1998; Dillon Consulting Limited, 2003). Solid Waste and Sewage Lagoon Facilities The Fort Liard sewage lagoon, active solid waste site and closed waste site are located 17 km southeast of the Hamlet of Fort Liard (the location of ERT Site R1 and borehole NWT01 in this study) (Figure A22) (Dillon Consulting Ltd., 2016a). The active solid waste facility began operating in 2011 and the site is suitable for six waste cells. These cells will be filled one at a time and are believed to last for 3 to 4 years each (Dillon Consulting Ltd., 2016a). In 2010, a geotechnical investigation was undertaken and found that the subsurface soils were mainly composed of peat overlying clay till. The hydraulic conductivity of the clay was 8.17x10-8 cm/s, indicating limited groundwater flow. However, below a depth of 2.5 m, the clay till was described as blocky, with fractures potentially facilitating increased groundwater flow through preferential pathways (Dillon Consulting Ltd., 2016a). During the investigation, eight test pits were completed

69 to depths ranging from 3.2 to 3.5 m. Of these, three pits encountered groundwater between 2.7 and 3.0 mbgs, four pits were dry and one pit experienced surface water infiltration and, therefore, was unusable (Dillon Consulting Ltd., 2016a). It should be noted that groundwater elevations at the sewage lagoon and solid waste facility were ~405 metres above sea level (masl) (Dillon Consulting Ltd., 2016a), whereas the elevation of the community of Fort Liard is ~200-215 masl (Figure 19) (Dillon Consulting Limited, 2003), which could indicate vastly different groundwater conditions. It should also be noted that baseline groundwater chemistry would be expected to be different at this site as it is not as proximal to surface water bodies as the Fort Liard wells. The water levels within the sewage lagoons are similar to those in the monitoring wells that exist on site, potentially indicating hydrologic connection between the sewage lagoons and shallow groundwater (Dillon Consulting Ltd., 2016a). Discharge from these cells may have adverse effects on surface water quality and, thus, groundwater quality (Dillon Consulting Ltd., 2016a). A comprehensive groundwater monitoring plan was proposed, which would involve 42 monitoring wells between six- and ten-meters deep spread throughout Fort Liard, Fort Simpson, Jean Marie River and Wrigley (Dillon Consulting Ltd., 2016b). Of the 42 total wells, eight were to be installed at the Fort Liard waste site. Four of these wells were to be located downgradient of the sewage lagoons to monitor groundwater and possible leachate. Three monitoring wells were to be placed downgradient of the current waste facility. One monitoring well was to be used as an upgradient background well to inform natural groundwater quality and contaminant levels (Dillon Consulting Ltd., 2016b). The installation of seven monitoring wells was completed on January 25, 2017 (Figure A22) and a first round of sampling was planned for August/September 2017. The results of this sampling round have not been released to date. These seven wells varied in depth from 5.49 mbgs to 9.14 mbgs (Dillon Consulting Ltd., 2017). None of the wells reached bedrock and were all generally completed in fine sand, or silt with a large clay component. The sediment at the sites was termed as dense and hard (Dillon Consulting Ltd., 2017). The eighth well, which was intended to be installed between the inactive solid waste facility and sewage lagoon, was unable to be completed due to safety concerns related to site access. According to previous work, there is a well in the area, although its condition is unknown. This well was to be assessed during the August/September 2017 initial sampling (Dillon Consulting Ltd., 2017). Surface water samples from the Liard River and Petitot River were also to be collected at this time. The groundwater and surface water samples were to be analyzed for fecal coliforms, BOD, CBOD, total dissolved solids (TDS), general chemistry, nutrients (nitrogen, ammonia), PCBs, PHC (BTEX and fractions F1 and F2) and metal parameters including mercury (Dillon Consulting Ltd., 2016b & Dillon Consulting Ltd., 2017). The depth to water within the seven completed monitoring wells was not stated. There is the potential that contaminated groundwater from the sewage facility could, over time, discharge to the Petitot River. The contaminated groundwater would be diluted, such that it is unlikely that a risk would be posed to the downstream community wells, but warrants further study. The unconsolidated sediments at the municipal waste facility are described as glacial till (Dillon Consulting Ltd., 2017), whereas the unconsolidated sediments at the community wells are glaciofluvial or fluvial deposits (Van Praet, 1988; Tam and Philip, 2002) and are separated by an elevation of ~200m, suggesting these two areas are likely not hydrologically connected and groundwater flow between them would be minimal, if present at all.

Oil and Gas Exploration in the Liard Basin The Liard is considered a frontier basin that is relatively unexplored (Morrow and Shinduke, 2003; Fiess et al., 2013). Exploration and development have been done in recent years but will likely increase, if and when oil and gas prices rebound or the region becomes more developed, making basin development more feasible (National Energy Board, 2016). Development has occurred in BC, and small portions of Yukon and NWT, but in general there are only a handful of exploration wells and very few proven reserves. From maturation data that has been collected, the top of the oil window is currently at 700 m within the Permian Fantasque to Carboniferous Mattson formations in the northern portion of the Liard Basin, while the base of the oil window lies at roughly 1350 m, within the Middle to Lower Carboniferous strata (Government of Yukon, 2001). The Middle Devonian to Mississippian-aged Exshaw and Patry shales are expected to contain 219 trillion cubic feet (tcf) (6.2 trillion cubic metres (tcm)) of marketable, unconventional natural gas, of this, 44 tcf (1.25 tcm) are expected to lie within the NWT (Figure A8) (National Energy Board, 2016). The Exshaw and Patry shales are found at depths of less than 1000 m on the northern edge of the Liard Basin and at roughly 4 km below ground surface in the basin centre. The Exshaw shale directly overlies the Patry and, together, have an estimated pay zone of 20-300 m thickness. The Exshaw-Patry shales are located within the Liard Basin’s Besa River Formation, which is roughly 300 m thick on the basin’s western edge, but up to 2000 m thick towards the Bovie Structure on basin’s the eastern edge (National Energy Board, 2016). In some regions the Dunvegan has been found to be locally gas charged (specifically the Deep Basin Montney Trend – South, Noel Field), but this phenomenon has not yet been observed within the Liard Basin and is not expected due to the shallower depths at which the Dunvegan Formation is located within the Liard Basin (Figure A23; Figure A24) (Riddell, 2012). Rather, the Dunvegan is thought to be an important aquifer in the Liard Basin. Most oil and gas plays or targets within the basin are associated with traps formed from faulted antiformal features, related to chert, carbonate, dolomite, shale, and other clastic sedimentary rocks (Government of Yukon, 2001). Exploration History and Knowledge Exploration within the Liard Basin started in the 1950s with the first well being drilled in the Liard Fold Belt at the Toad River Anticline. Amoco Canada Petroleum Co. Ltd. made the first viable discovery at the Beaver River Field shortly after in 1958. With continued exploration and drilling, the Beaver River pool was properly delineated and additional discoveries were made in the 1960s at Pointed Mountain in the NWT and Kotaneelee, Yukon, which are both accessed via Fort Liard on the Liard River (Walsh et al., 2005). Additionally, production is ongoing at British Columbia’s Maxhamish Field since the late 1990s (Figure A23; Figure A24) (National Energy Board, 2016). It should be noted that the above discoveries are all conventional gas reserves (National Energy Board, 2016). More recent exploration has found new pools within the Devonian Nahanni Formation north of Fort Liard region (Walsh et al., 2005). Both Apache Corporation and Paramount Resources Ltd. announced major shale gas discoveries within the northeast BC region of the Liard Basin in recent years (Fiess et al., 2013; Hayes and Costanzo, 2014). The Liard Plateau and Liard Basin offer a setting of stratigraphic conditions suitable for the sourcing, migration and entrapment of hydrocarbons. For these reasons, a thorough understanding of the stratigraphy and depositional setting is important for the analysis of discovered hydrocarbon accumulations, and for predicting possible accumulations volumes (Government of Yukon, 2001). Our objectives are to understand the overlying freshwater zone and the intermediate zones

71 comprised of lower and higher transmissivity formations and their hydrogeologic unit boundary conditions, as well as the likely varying hydrochemistry that depends on the 3-D flow system dynamics and interactions. Dunvegan Formation and Oil and Gas Regarding the Dunvegan Formation and oil and gas, it is said that the Dunvegan is an excellent potential source for hydraulic fracturing water but would be unsuitable for wastewater disposal (Lowen, 2011; Hayes, 2013; Hayes and Costanzo, 2014). The thick, very coarse-grained nature of the Dunvegan signify the potential for a good reservoir, while the shallow depth of burial makes water sourcing attractive, but likely precludes disposal. These characterizations were completed with the help of well logs, sample cuttings and outcrop descriptions, but the available dataset is limited, and more work needs to be done (Hayes, 2013). Knowledge Gaps It is emphasized in many of the relevant papers that detailed baseline studies are needed at the sub- basin and basin scale to try and ascertain natural formation and flow system conditions before further development disrupts or overprints the natural basin conditions (Lowen, 2011; Hayes, 2013; Uwiera-Gartner, 2013; Jackson et al., 2013; Council of Canadian Academies, 2014; McIntosh et al., 2018). These studies are called for throughout the entirety of these natural gas basins to gain a greater overall understanding of the basin dynamics and formation fluid quality. However, generally these studies occur much deeper in the pay zone as this is the region that oil and gas companies are most interested in. Therefore, the Dunvegan is commonly not studied, as it is often behind casing due to its shallow depth (Hayes, 2013). This is due to the BC drilling and production regulations under the Oil and Gas Activities Act (2010), which prohibit hydraulic fracturing above 600 m and stipulate that surface casing must be set to a base of known fresh groundwater aquifers or to 600 m depth (Riddell, 2012). This is aimed at protecting non-saline groundwater, with freshwater wells rarely being drilled to depths greater than 150 m in the region and results in less research interest in the Dunvegan from an oil and gas perspective, where wells are generally only logged and sampled below 300 m depth (Riddell, 2012). However, several papers state that a greater overall understanding of the Liard Basin dynamics and Dunvegan Formation is important to better identify baseline groundwater conditions in the face of continued or increased O&G exploration and development (Lowen, 2011; Hayes, 2013; Uwiera-Gartner, 2013; Jackson et al., 2013; Council of Canadian Academies, 2014; McIntosh et al., 2018).

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Table A1: Liard and Petitot Rivers and Fort Liard Community Wells water quality.

Summary of water quality data from the Liard River, Petitot River and Community Groundwater Wells during periods in 1983 and 1984 (from Dillon Consulting Limited, 2003).

Sample Date Total hardness (mg/L) Total iron (mg/L) Dissolved iron (mg/L) Manganese (mg/L) Calcium (mg/L) Chloride (mg/L) Sodium (mg/L) Liard River Aug-83 129 0.38 0.1 NT 37 4 4* Mar-84 198 0.12 <0.05 0.015 55 3 4 Petitot River Aug-83 130 0.2 0.08 0.04 39 3 5 Mar-84 320 0.33 0.12 0.032 95 8 29 Groundwater Well Jan-84 160 0.08 NT NT 40 7 8 Note: NT - Not Tested *Sodium+Potassium

Table A2: Fort Liard raw water quality results.

Summary of raw well water quality results from the Fort Liard community wells from periodic sampling between 1999-2003 (from Dillon Consulting Limited, 2003).

Sample Date Total hardness (mg/L) Iron (mg/L) Sodium (mg/L) Manganese (mg/L) Fluoride (mg/L) Sulphate (mg/L) Total Dissolved Solids (mg/L) Raw Groundwater from Wells Oct-99 NT 0.38 NT 0.054 NT NT 633 Oct-99 328 0.74 15.4 0.081 NT NT 314 Aug-00 109 0.81 12.8 0.071 0.14 <0.030 NT Sep-00 NT 0.675 NT 0.078 <0.10 <0.020 306 Oct-00 NT 0.675 11 0.078 <0.10 <0.020 306 Aug-01 NT 0.645 14 0.079 0.12 0.027 320 Jan-03 NT 0.373 18 0.184 0.1 <0.020 370 Note: NT - Not Tested

Figure A1: Basins of relevance with respect to the Dunvegan Formation

Map detailing the different scales and basins of relevance to this study. The Dunvegan Formation was deposited within and is present within the WCSB and the Liard Basin (which is a part of the WCSB). The Liard Basin watershed funnels surface water into the Liard Basin and from there flows northwards. The Dunvegan Formation presently is located within parts of NWT, YT, BC and AB.

Figure A2: Map of the Dunvegan Formation and study sites around Fort Liard

Map detailing the ERT survey locations (labelled R1-R5) and NWT01, which are the data points relevant to the Dunvegan Formation within the NWT. Their proximity to the Hamlet of Fort Liard is shown, as well as their proximity to surface water bodies. A geologic map showing the Dunvegan and Kotaneelee Formations, along with relevant faults, are shown for reference.

Figure A3: Liard Basin map with associated datasets collected.

Map detailing the extent of the Dunvegan Formation within the larger Liard Basin, with Stott (1982) outcrop locations shown as white with a black rim, well log locations of various origin shown as white with a blue rim, with those that also contain hydraulic conductivity and porosity data shown with an orange rim. Dunvegan and Kotaneelee Formation geology is shown for reference.

Figure A4: Late Albian paleogeographic map

Paleogeographic reconstruction showing the initial stages of flooding that created the CWIS just prior to Dunvegan deposition during the Late Albian, at which time the Sully Formation (analogous to the Shaftesbury Formation) was deposited (from Blakey, 2014).

Figure A5: Middle Cenomanian paleogeographic map

Paleogeographic reconstruction showing the mid-Cenomanian, when the majority of the Dunvegan Formation was deposited, with the CWIS connecting to the Gulf of Mexico-Tethys Sea (from Blakey, 2014).

Figure A6: Late Cenomanian paleogeographic map

Paleogeographic reconstruction showing the late Cenomanian, as the CWIS continues to expand, starting to submerge Dunvegan Formation deposits (from Blakey, 2014).

Figure A7: Early Turonian paleogeographic map

Paleogeographic reconstruction showing the Early Turonian, at which point the CWIS had completely submerged Dunvegan Formation deposits. At this time the Kotaneelee Formation would have been deposited (from Blakey, 2014).

Figure A8: Cross section showing the Pre-Devonian to Cretaceous units within the Liard Basin

Cross-section of the Liard Basin, with the Exshaw marker indicating the location of the Exshaw-Patry shale, the major gas bearing unit within the Liard basin. To the east of the Bovie Fault Zone is the Horn River Basin, while the Liard Basin lies to the west with a large structural drop being present, which alters the formation thicknesses considerably. This figure cuts off the top portion of the Cretaceous, but it should be noted that the Dunvegan Formation does extend beyond the Liard Basin. Previously discovered gas shows and pools are represented by a pink star. The Maxhamish Field, which is a producing field in northeast BC is also marked on the figure. (from Morrow & Shinduke, 2003).

Figure A9: Development of the Bovie Structure through time

Series of time slices detailing the development of the Bovie Structure through time proximal to the study site. Note the affect on Cretaceous sediments proximal to the Bovie Structure (from McLean & Morrow, 2004).

Figure A10: Paleogeographic map detailing depositional environments of the Dunvegan Formation

Paleogeographic depiction of North America during the Cenomanian, outlining the CWIS and the Dunvegan Formation, with deltaic deposits shown in yellow and terrestrial deposits (light pink) with their tributary streams (blue). Note that the most northern source area is within YT and NWT, proximal to the study area (from Bhattacharya et al., 2016).

Figure A11: Paleogeographic map detailing the major lithologies of the Dunvegan Formation

Paleogeographic construction showing the transition in lithology within the Dunvegan Formation from source to sink, with arrows detailing regions of grain size increase potentially indicating sediment input and present outcrop locations for reference. The delta front, coastal shoreline and marine deposits have been identified through core as they are present within the subsurface (modified from Stott, 1982).

Figure A12: Cross section illustrating a typical lithostratigraphic depiction of the Dunvegan Formation

Two cross sections across the Liard Basin, depicting the Dunvegan Formation as a pink band of uniform thickness and lacking internal heterogeneity (shown in the top right corner of both sections). This is a typical depiction of the Dunvegan Formation in cross section due to the lack of background information that exists on the Dunvegan Formation’s northern extent, or the study objectives not focusing on the Dunvegan Formation (from McMechan et al., 2012).

Figure A13: Cross section detailing the heterogeneity within the Dunvegan Formation

Schematic diagram illustrating facies and approximate thicknesses of the Dunvegan Formation. This shows that the Dunvegan Formation has a large component of conglomerate and sandstone mix. It also shows that the Dunvegan Formation thickness is variable across the region. This cross section does not utilize more modern sequence stratigraphic methods, but instead more simply connects similar lithologies together (from Stott, 1982).

Figure A14: Dunvegan allomembers within the Peace River Region

Summary of the Dunvegan Formation allomembers (A-J), along with their lithostratigraphic relationships to the overlying and underlying formations. The base of the Dunvegan alloformation is diachronous and marked by the allomembers downlapping onto the FSU marker within the Shaftesbury Formation. This schematic shows a thick wedge in the NNW that thins to the SSE. The Peace River Area and Athabasca River Area are marked on Figure A1 for reference (from Plint, 1996).

Figure A15: Schematic depicting main features of a Dunvegan Formation fluvial-dominated valley fill

Schematic summarizing the main features of an updip, fluvial-dominated valley fill. This schematic was created based on outcrop within the Peace River Region (see Figure A1), helping to give a sense of the scale and complexity of these valley infills (from Plint & Wadsworth, 2003).

Figure A16: Depositional morphology preservation as a function of aggradation, migration and avulsion

Schematic diagram illustrating the preservation of depositional morphology as a function of the aggradation rate, lateral channel migration rate and channel-belt avulsion rate. The frequency or rate at which these three mechanisms operate can result in similar depositional systems or channel types having strikingly different appearances within the rock record. Therefore, it is important to consider aggradation, migration and avulsion and not rely solely on whether the system is dominated by braided or meandering rivers (from Bristow & Best, 1993).

Figure A17: Discontinuous Dunvegan Formation aquifers within the Peace River Region

Schematic showing the erosive features which have caused the Dunvegan Formation to be discontinuous in some portions of the Peace River Region, ~600 km south of Fort Liard. These erosional incised channels are variable across the region (from Lowen, 2011).

Figure A18: Mackenzie River Watersheds permafrost locations.

Permafrost in the Mackenzie River Basin. It should be noted that within the Liard sub-basin isolated patches and sporadic discontinuous permafrost regimes dominate. Within the Fort Liard region, sporadic discontinuous permafrost is present, with extensive discontinuous permafrost being located just to the northwest. Drilling projects that have occurred to date within the Fort Liard region have not encountered any permafrost (from VanGulck, 2016).

Figure A19: Liard River to potential drill sites.

Schematic detailing the locations of the potential G360 Institute for Groundwater Research monitoring wells in relation to the community of Fort Liard, the Fort Liard Community Wells and the Liard River. The elevation difference between the town of Fort Liard and the potential University of Guelph monitoring well sites is roughly 200 m. The Fort Liard Community Wells have been found to be hydrologically connected to the Liard and Petitot Rivers. In Spring and high flow conditions, the river recharges the aquifer. In Fall and low flow conditions, the aquifer provides baseflow to the river. It should be noted that the Fort Liard Community Wells are ~10 m from the Liard River. The three potential drilling sites are the weigh scale, sewage and solid waste site and Northwestel tower, which are 6.5 km, 14.5 km and 30.5 km from the Community of Fort Liard, respectively. The three drilling sites lie roughly 3 km northeast of the Petitot River if a line were to be drawn from Fort Liard southeast along the Petitot River (see Figure A2 for reference).

Figure A20: Fort Liard community wells in relation to Liard and Petitot Rivers.

Google Earth image showing the location of the Fort Liard Community Wells in relation to the Petitot and Liard Rivers. It should be noted that the Petitot and Liard Rivers have not yet mixed as they pass the Fort Liard Community Wells, which is where the determination that the Petitot River contributes more to the Fort Liard Community Wells was determined. Arrows detail river flow directions.

Figure A21: Liard and Petitot Rivers confluence.

Black and White aerial photograph showing the Petitot River and Liard River confluence, with the Petitot River being darker than the Liard River. The water treatment facility is located near the confluence of the two rivers and given that the municipal wells are hydrologically linked to surface water, they are likely most impacted by the Petitot River (from Dillon Consulting Limited, 2003).

Figure A22: Monitoring well locations within the municipal waste facility.

Schematic detailing the layout of the sewage and solid waste site, as well as the associated monitoring wells. The box in the upper left corner illustrates the sewage and solid waste sites location in relation to the Hamlet of Fort Liard (from Dillon Consulting, 2003).

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Figure A23: Bedrock geology map with gas fields shown.

Bedrock geology map compilation of northeast British Columbia. Cretaceous bedrock units are coloured according to their predicted aquifer characteristics. Coarse clastic formations that can be expected to host aquifers are brighter hues of yellow, orange or green. For contrast, dominantly shaley formations that are expected to form aquitards are coloured dull grey or brown. The same colour scheme is used for Figure A24. The Montney trend and the Horn River Basin are active regions for shale gas development. The Liard Basin and the Cordova Embayment have shale gas potential. These regions overlap many conventional oil and gas plays. It should be noted that only within the Deep Basin Montney Trend – South, Noel Field is the Dunvegan Formation found to be gas charged and an unconventional/shale gas target. The Noel Field is roughly 100 km South of Dawson’s Creek, or ~750 km south of Fort Liard (from Riddell, 2012). Inset: oil and gas geographic regions in northeast British Columbia.

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Figure A24. Geology of eight selected gas fields in northeastern British Columbia

The locations of gas fields are shown in Figure A23. Units occurring at surface or in the shallow subsurface are shown by a blue vertical bar. For reference, the gas, oil or water targets, producing and disposal formations at the various field are noted with coloured dots and the depth range of the shallowest producing formations are noted. Information on the target formations and their depths were determined using AccuMap and geoSCOUT. It should be noted that only within the Deep Basin Montney Trend – South, Noel Field is the Dunvegan Formation found to be gas charged and an unconventional/shale gas target. The Noel Field is roughly 100 km South of Dawson’s Creek, or ~750 km south of Fort Liard (from Riddell, 2012; Stott, 1982; British Columbia Ministry of Energy and Mines, 2012).

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Appendix B: Lab Method and Lab Results for Non-Reported Samples

Contents Methods ...... 104 Hydrocarbon Gas Composition and Isotope Methods ...... 105 Moisture Content and Major Ion Chemistry Methods ...... 106 Water Isotope Analysis Methods ...... 106 Direct Vapour Equilibration Method ...... 106 Vacuum Distillation Method ...... 107 Results ...... 107 Hydrocarbon Gas Composition and Stable Isotope Analysis ...... 107 Isotopes of Water Analysis ...... 107 Moisture Content ...... 108 References ...... 109

List of Tables

Table B1: Moisture content, ion, gas composition and isotope sample depths ...... 110 Table B2: Direct Vapour Equilibration sample depths ...... 111 Table B3: Vacuum Distillation sample depths ...... 112 Table B4: Summary of results for gas composition analysis ...... 113 Table B5: Summary of preliminary results for δ2H, δ18O and δ17O analysis ...... 114 Table B6: Calculated water content of water isotope samples ...... 115 Table B7: Moisture content sample results ...... 116

List of Figures

Figure B1: Cartoon depicting idealized whole core subsampling approach ...... 117 Figure B2: Cartoon depicting idealized core puck subsampling approach ...... 118 Figure B3: Hydraulic press used for rock crushing during sample processing ...... 119 Figure B4: 18O/2H results plotted against the GMWL, LMWL and LEL ...... 120

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In addition to sample methodology and analyses described in the main text, other samples were collected for additional analyses. These samples and associated analyses are discussed below, and additional research is ongoing to further these datasets through additional data collection and method refinement.

Methods Collected rock core samples were misplaced along their shipping route and thus arrived at the University of Guelph late and with the chest freezer having an internal temperature of ~7 °C. The chest freezer was plugged into the lab, the samples were refrozen and remained frozen at the University of Guelph until processed and subsampled for various laboratory analyses on February 18 and 19, 2020. The loss of the freezer during shipment and the subsequent sample thawing and re-freezing could have impacted lab results. As is discussed below, it is expected that the thawing and re-freezing of samples could have resulted in erroneously low moisture content values. Sample hydrochemistry is not expected to have been affected, however, there is the potential for some isotopic fractionation during the thawing and re-freezing process. It should further be noted that while the samples did thaw out, the freezer’s internal temperature being ~7 °C does still match with natural groundwater temperatures, indicating that the rock core porewater was not exposed to unnatural temperatures. Rock core samples were subsampled for hydrocarbon gas composition (C1 to C4) and compound specific isotope analysis (CSIA), major ion chemistry, moisture content, isotopes of water and physical properties. Each of the 22 samples were removed from the freezer and processed individually. First, the vacuum sealed double mylar bags were cut open and the sample unwrapped by removing the layers of Parafilm and aluminum foil. The freezing process resulted in the Parafilm becoming very brittle and the aluminum foil adhering to the samples. Once all remnants of parafilm and foil were removed from the sample, the sample was examined, and the subsampling locations marked and photographed (Figure B1). Second, a chisel and mallet were used to break the core into four smaller pucks and one large piece. To ensure minimal influence from evaporation and diffusion, the puck at the end of the core sample was discarded entirely and the three internal pucks were allocated for analysis. The first two pucks (3-5 cm in length along the core axis each) were kept for analyses of isotopes of water, while the third puck (4-7 cm in length along the core axis) was allocated for hydrocarbon gas composition, hydrocarbon gas isotopes, moisture content and major ion chemistry (major ion chemistry is discussed in the main text, so is not discussed here). This third puck sample was immediately crushed and bottled, such that exposure to air was minimal. The remaining larger piece of core, roughly 15 cm in length, was retained for physical property measurements by Golder Associates Ltd. (Mississauga, ON). Remaining samples not adequate for physical property analysis were re-wrapped in aluminum foil, Parafilm and double vacuum sealed in mylar bags for storage for potential thin section analysis. As described above, the third puck was used for light hydrocarbon gas composition (C1 to C4) and CSIA analyses, moisture content and major ion chemistry. Each of these required the rock be crushed and placed in a pre-prepared bottle. This puck, roughly 4-7 cm in length (along the core axis) and weighing ~ 90 grams was placed in an open-top stainless steel chamber and the chisel and mallet were used to break it into four smaller pieces, ideally into quadrants, with opposite quadrants being used for individual samples to reduce bias (Figure B2). The hydrocarbon porewater

104 concentrations and CSIA samples required approximately 25 grams (g) of crushed rock each, whereas the moisture content and major ion chemistry sample required approximately 40 g of crushed rock (Figure B3). The COREDFN rock core sampling methodology described in Sterling et al. (2005), Manna et al. (2017) and Pierce et al. (2018), includes trimming the rind of the intact puck prior to crushing. Trimming reduces the risk of drilling fluid contamination; however, these cores were not trimmed because experience has shown that when drilling with water that this step is not necessary if core is observed to be clean and wiped off when retrieved at surface in the field (Parker, personal communication, 2020). The methodology in the field ensured clean and well- preserved core at the time of collection, which was then frozen to preserve porewater conditions. Therefore, the entire cross-sectional area of core was used. The rock pieces were crushed using a hydraulic device and preserved in associated sample bottles (described below). After each sample was crushed, the rock crushing equipment was decontaminated utilizing baths of water, Alconox and methanol. Hydrocarbon Gas Composition and Isotope Methods Crushed rock samples for porewater gas composition and their compound specific (C, H) stable isotopic ratios were placed in 60 mL volatile organic analysis (VOA) vials (clear glass) equipped with open lids with chlorobutyl rubber septa, found to be the most effective at stopping gas diffusion from samples (Eby, Gibson & Yi, 2015). Two vials were prepared, one each for gas concentrations and isotope analysis, respectfully. Each VOA vial was weighed empty with cap, septa and label, prior to adding approximately 30 millilitre (mL) of de-gassed, helium-sparged, nanopure water and 0.2 mL of benzalkonium chloride solution. De-gassing and sparging the nanopure water with helium removes free oxygen, thus minimizing the oxidation of possible hydrocarbons present in the sample for preservation of field conditions. The benzalkonium chloride solution acts as a biocide, killing remaining microbes that may degrade methane. Each vial was re-weighed with the de-gassed, helium-sparged, nanopure water and benzalkonium chloride solution, then re-weighed once the crushed rock was added to the vial. To eliminate any remaining headspace within the vial after the rock was added, additional de-gassed, helium- sparged, nanopure water was added and the vial re-weighed one last time. The four weights were used to calculate the exact mass of the crushed rock in each vial and volume of water extract added to inform masses and concentrations. An important baseline groundwater quality parameter is the composition of gas present in the matrix porewater. Gas composition combined with the stable hydrogen and carbon isotope composition of those gases provides important information about the gases present and the origin of these gases. A total of 22 samples were submitted to the University of Calgary Isotope Science Laboratory for gas composition and an additional duplicate set of samples were sent for complimentary CSIA analyses, if applicable (Table B1). Once the samples arrived, headspace was created within the sample vials with syringes by withdrawing 12 mL of water while filling the vial simultaneously with 12 mL of ultra-high purity helium (UHP5.0) at 1 atmosphere (atm). Samples were then shaken for 5 minutes and allowed to equilibrate for four hours at 25 °C. Afterwards, 5 mL of head-space gas was removed and analyzed on a Bruker 450 gas chromatograph (GC). Reported concentrations of methane (C1), ethane (C2), propane (C3), and butane (C4) were not sufficiently high to conduct stable hydrogen or carbon isotope analysis.

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Moisture Content and Major Ion Chemistry Methods For rock matrix moisture content and major ion chemistry samples, only one pre-weighed 60 mL high-density polyethylene (HDPE) bottle is required. Approximately 40 g of crushed rock was placed directly in the empty bottle and then each bottle was weighed again. The samples were left to dry in an oven at 40 °C until the weight equilibrated to a constant value. Once dry, the pre- and post-drying weights were used to calculate moisture content and then re-hydrated with nanopure water for major ion chemistry analysis as described in the main text. These samples were dried at the University of Guelph. Moisture content for each rock sample is calculated based on the change in mass from the original wet sample to a dried sample and plotted with depth (Table B1). Crushed samples in the 60 mL HDPE bottles were placed in the oven at 40 °C on February 19, 2020. Samples were re-weighed one to two times per week to track the loss of mass and were considered dry once three consecutive weighing’s showed the same mass within roughly +/- 0.001 g. Water Isotope Analysis Methods The stable isotope composition of water provides insight into the origin of groundwater; important recharge processes, such as rapid infiltration through fractures or slow infiltration in the matrix (Manna et al., 2017); and the regional groundwater flow system from recharge to discharge. The important stable isotope ratios of oxygen and hydrogen in water include 18O/16O, reported as δ18O, the less commonly used 17O/16O, reported as δ17O, and 2H/H, reported as δ2H. The methods available for obtaining the stable isotope composition of rock core porewater are limited due to the need for sufficient water sample volume and efforts to properly extract without fractionation. Samples were prepared to be submitted to two laboratories to compare two of these methods: Direct Vapour Equilibration (DVE) and Vacuum Distillation (VD). DVE, is a faster and simpler method that allows for processing numerous samples to obtain depth-discrete profiles cost- effectively. However, it is less reliable for samples that have a lower water content (<8%) (Orlowski et al., 2016) or smaller porosity/permeability, where more time may be needed for samples to equilibrate, or where a higher resolution is needed for quantitative results to be obtained with confidence. The VD method takes more time with respect to both analysis and personnel time but can provide reliable results for very tight rocks with little permeability and porosity and lower water content (Clark, personal communication, 2019). The August 2019 drilling activities provided an excellent opportunity to evaluate these methods as a trial to determine the reliability of the DVE method and inform the number of samples suitable for these measurements at future drilling locations. Direct Vapour Equilibration Method As discussed previously, two sets of samples were prepared for water isotope analysis. The first set of 22 samples were submitted to the University of Saskatchewan Hillslope Hydrology Lab, part of the Global Institute for Water Security, for the DVE method (Table B2). Upon arrival at the lab, the samples were removed from the mylar bags, unwrapped and broken apart using a mallet and chisel. The rock pieces were placed into a ZiplockTM-type bag, fully evacuated of all ambient air and sealed. The ZiplockTM-type bags were then re-inflated with dry air, sealed and allowed to equilibrate at room temperature for 48 hours prior to air space sampling for water vapour isotope analysis using a Los Gatos Research Liquid and Vapor Water Off-Axis Integrated-Cavity Output Spectroscopy machine as described by Wassenaar et al. (2008) and Hendry et al. (2015).

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Vacuum Distillation Method The second set of samples, consisting of 21 samples, were allocated for the vacuum distillation method for obtaining a complimentary dataset for stable isotopes (Table B3). This method requires a competent puck of rock core, therefore, only 21 of the 22 core samples were deemed appropriate. These samples are currently being kept frozen at the University of Guelph and will be shipped to the University of Ottawa Advanced Research Complex (ARC) when analysis time is available, as the VD equipment is currently being reconfigured and re-tested. It should be noted that due to the COVID-19 Pandemic, University of Ottawa Staff are working from home where possible and the ARC lab where samples would be analyzed is closed for new sample submission until further notice. Dr. Ian Clark has communicated that dialogue surrounding the processing and analysis of these samples will continue once normal operations resume. Results Hydrocarbon Gas Composition and Stable Isotope Analysis Detected concentrations of hydrocarbons were generally low, indicating a lack of abundance of these gasses in the matrix porewater (Table B4). Such low concentrations indicate the natural occurrence of gasses is minimal in the shallow subsurface at the MWF Site with some uncertainty regarding negative bias imparted by the sample storage and preparation methods applied. Additional sampling of both rock core and groundwater from multi-level systems during future field events will help to assess these biases. Sampling of both the rock core and the groundwater at discrete intervals will provide insight into where hydrocarbon gases are present and distributed within the shallow groundwater system. Isotopes of Water Analysis The results from these analyses are provided and plotted with both the global meteoric water line (GMWL) and local meteoric water line (LMWL) (Table B5; Figure B4). The GMWL and LMWL describe the annual average relationship between hydrogen and oxygen isotopic ratios in precipitation, on a global and local scale, respectively (Craig, 1961). The stable isotopic ratios of hydrogen and oxygen in precipitation varies depending on climatic factors, such as temperature and humidity, as well as elevation. These factors vary across North America and are best represented by a LMWL. The stable isotopic ratio of oxygen and hydrogen within groundwater systems helps elucidate the origin of groundwater and understand groundwater recharge dynamics, based on comparison to both the GMWL and LMWL. The plot shows all but three samples plot above the GMWL, which is uncommon for soil/rock water. The laboratory conducted a detailed quality assurance and quality control (QA/QC) assessment and determined the results were correct. As an additional measure, the laboratory calculated the gravimetric water content for each sample by baking a subsample of rock from each sample in an oven. The calculated water content ranged from 0.42% to 8.61%, with an average of 4.77% (Table B6). Previous studies have shown that DVE is not reliable for water contents below 8% (Orlowski et al., 2016), which may be an explanation for the results plotting above the GMWL. It is also important to consider the effects of freezing samples on moisture loss and possible fractionation. Additionally, it is more relevant to compare samples to a LMWL and a local evaporation line (LEL) for soil, both available from study areas near Yellowknife, NWT (Gibson et al., 1993; Gibson et al., 2008; Gibson & Reid, 2010). The LMWL is similar to that of the GMWL, whereas the LEL matches the data much better, with all samples plotting just below yet parallel to the LEL, suggesting the results are potentially

107 reasonable within this framework. It is worth noting that LMWLs and LELs vary due to topography and climate, thus additional comparison data would be beneficial as Fort Liard is ~550 km away from Yellowknife and close to the Mackenzie Mountains making it geographically distinct from Yellowknife. It is proposed that an atmospheric deposition collector, placed near Fort Liard for collecting local data would be valuable for comparison to future datasets. A discussion with the laboratory scientist, Kim Janzen, has revealed options for further analysis of method bias, limitations and modifications relevant to the reliability of future analysis that is being advanced collaboratively. Moisture Content Similar to the calculated gravimetric water content values completed during the isotopes of water analysis, the moisture content values were also lower than expected, likely as a result of the sample storage freezer being lost during transit and the samples arriving at the lab defrosted. In future sample collection rounds, samples will be shipped in a cooler, instead of being frozen, to avoid the water loss that occurred during the freezing/defrosting process. The moisture content values obtained ranged between 5.23-10.79 wt.%, with an average value of 7.13 wt.% (Table B7). These values are similar but slightly higher than the water contents calculated during the water isotope analysis, likely due to more complete crushing and longer drying period utilized during the moisture content calculations.

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References Craig, H., 1961. Isotopic variations in meteoric waters. Science, 133(3465), pp.1702-1703. Eby, P., Gibson, J. J., & Yi, Y., 2015. Suitability of selected free‐gas and dissolved‐gas sampling containers for carbon isotopic analysis. Rapid Communications in Mass Spectrometry, 29(13), 1215-1226. Gibson, J. J., Edwards, T. W. D., Bursey, G. G., & Prowse, T. D., 1993. Estimating Evaporation Using Stable Isotopes: Quantitative Results and Sensitivity Analysis for Two Catchments in Northern Canada: Paper presented at the 9th Northern Res. Basin Symposium/Workshop (Whitehorse/Dawson/Inuvik, Canada-August 1992). Hydrology Research, 24(2-3), 79-94. Gibson, J. J., Birks, S. J., & Edwards, T. W. D., 2008. Global prediction of δA and δ2H‐δ18O evaporation slopes for lakes and soil water accounting for seasonality. Global biogeochemical cycles, 22(2). Gibson, J. J., & Reid, R., 2010. Stable isotope fingerprint of open-water evaporation losses and effective drainage area fluctuations in a subarctic shield watershed. Journal of Hydrology, 381(1- 2), 142-150 Hendry, M. J., Schmeling, E., Wassenaar, L. I., Barbour, S. L., & Pratt, D., 2015. Determining the stable isotope composition of pore water from saturated and unsaturated zone core: improvements to the direct vapour equilibration laser spectrometry method. Hydrology and Earth System Sciences, 19(11), 4427. Manna, F., Walton, K. M., Cherry, J. A., & Parker, B. L., 2017. Mechanisms of recharge in a fractured porous rock aquifer in a semi-arid region. Journal of Hydrology, 555, 869-880. Orlowski, N., Pratt, D. L., & McDonnell, J. J., 2016. Intercomparison of soil pore water extraction methods for stable isotope analysis. Hydrological Processes, 30(19), 3434-3449. Pierce, A. A., Chapman, S. W., Zimmerman, L. K., Hurley, J. C., Aravena, R., Cherry, J. A., & Parker, B. L., 2018. DFN-M field characterization of sandstone for a process-based site conceptual model and numerical simulations of TCE transport with degradation. Journal of contaminant hydrology, 212, 96-114. Sterling, S. N., Parker, B. L., Cherry, J. A., Williams, J. H., Lane Jr, J. W., & Haeni, F. P. (2005). Vertical cross contamination of trichloroethylene in a borehole in fractured sandstone. Groundwater, 43(4), 557-573. Wassenaar, L. I., Hendry, M. J., Chostner, V. L., & Lis, G. P., 2008. High resolution pore water δ2H and δ18O measurements by H2O (liquid)− H2O (vapor) equilibration laser spectroscopy. Environmental science & technology, 42(24), 9262-9267.

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Table B1: Moisture content, ion, gas composition and isotope sample depths

Moisture Content, Ion, Gas Composition and Isotope Samples MC/Ion Sample Gas Composition Gas Isotope Top Bottom Length # Sample # Sample # Depth (m) Depth (m) (m) NWT01-An-001 NWT01-GC-001 NWT01-GI-001 7.71 7.74 0.03 NWT01-An-002 NWT01-GC-002 NWT01-GI-002 8.15 8.20 0.05 NWT01-An-003 NWT01-GC-003 NWT01-GI-003 8.63 8.66 0.03 NWT01-An-004 NWT01-GC-004 NWT01-GI-004 26.05 26.09 0.04 NWT01-An-005 NWT01-GC-005 NWT01-GI-005 26.63 26.66 0.03 NWT01-An-006 NWT01-GC-006 NWT01-GI-006 26.91 26.94 0.03 NWT01-An-007 NWT01-GC-007 NWT01-GI-007 28.11 28.14 0.03 NWT01-An-008 NWT01-GC-008 NWT01-GI-008 28.41 28.44 0.03 NWT01-An-009 NWT01-GC-009 NWT01-GI-009 33.88 33.91 0.03 NWT01-An-010 NWT01-GC-010 NWT01-GI-010 34.32 34.35 0.03 NWT01-An-011 NWT01-GC-011 NWT01-GI-011 40.65 40.68 0.03 NWT01-An-012 NWT01-GC-012 NWT01-GI-012 41.21 41.25 0.04 NWT01-An-013 NWT01-GC-013 NWT01-GI-013 41.76 41.79 0.03 NWT01-An-014 NWT01-GC-014 NWT01-GI-014 42.65 42.68 0.03 NWT01-An-015 NWT01-GC-015 NWT01-GI-015 43.31 43.36 0.05 NWT01-An-016 NWT01-GC-016 NWT01-GI-016 44.16 44.20 0.04 NWT01-An-017 NWT01-GC-017 NWT01-GI-017 45.31 45.35 0.04 NWT01-An-018 NWT01-GC-018 NWT01-GI-018 45.78 45.81 0.03 NWT01-An-019 NWT01-GC-019 NWT01-GI-019 47.40 47.43 0.03 NWT01-An-020 NWT01-GC-020 NWT01-GI-020 48.19 48.22 0.03 NWT01-An-021 NWT01-GC-021 NWT01-GI-021 48.57 48.60 0.03 NWT01-An-022 NWT01-GC-022 NWT01-GI-022 49.85 49.88 0.03 - NWT01-GC-023D NWT01-GI-023D 41.25 41.27 0.02 - NWT01-GC-024D NWT01-GI-024D 43.31 43.36 0.05

Notes: This table details the depths and lengths of samples collected for moisture content, major ion, gas composition and gas isotope analysis. It can be noted that sample numbers are all from the same depths across the different analyses (i.e. An-001, GC- 001, GI-001).

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Table B2: Direct Vapour Equilibration sample depths

Direct Vapour Equilibration Samples DVE Sample # Top Depth (m) Bottom Depth (m) Length (m) NWT01-DVE-001 7.84 7.87 0.03 NWT01-DVE-002 8.10 8.13 0.03 NWT01-DVE-003 8.69 8.72 0.03 NWT01-DVE-004 25.98 26.02 0.04 NWT01-DVE-005 26.66 26.69 0.03 NWT01-DVE-006 26.86 26.89 0.03 NWT01-DVE-007 28.06 28.09 0.03 NWT01-DVE-008 28.36 28.39 0.03 NWT01-DVE-009 33.83 33.86 0.03 NWT01-DVE-010 34.27 34.30 0.03 NWT01-DVE-011 40.60 40.63 0.03 NWT01-DVE-012 41.27 41.30 0.03 NWT01-DVE-013 41.81 41.84 0.03 NWT01-DVE-014 42.68 42.70 0.02 NWT01-DVE-015 43.26 43.29 0.03 NWT01-DVE-016 44.10 44.14 0.04 NWT01-DVE-017 45.24 45.28 0.04 NWT01-DVE-018 45.75 45.78 0.03 NWT01-DVE-019 47.35 47.38 0.03 NWT01-DVE-020 48.13 48.16 0.03 NWT01-DVE-021 48.63 48.66 0.03 NWT01-DVE-022 49.80 49.83 0.03

Notes: This table details the depths and lengths of samples collected for DVE analysis.

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Table B3: Vacuum Distillation sample depths

Vacuum Distillation Samples VD Sample # Top Depth (m) Bottom Depth (m) Length (m) NWT01-VD-001 7.87 7.89 0.02 NWT01-VD-002 8.13 8.15 0.02 NWT01-VD-003 8.66 8.69 0.03 NWT01-VD-004 26.02 26.05 0.03 NWT01-VD-005 26.69 26.71 0.02 NWT01-VD-006 26.89 26.91 0.02 NWT01-VD-007 28.09 28.11 0.02 NWT01-VD-008 28.39 28.41 0.02 NWT01-VD-009 33.86 33.88 0.02 NWT01-VD-010 34.30 34.32 0.02 NWT01-VD-011 40.63 40.65 0.02 NWT01-VD-012 41.30 41.32 0.02 NWT01-VD-013 41.79 41.81 0.02 - - - - NWT01-VD-015 43.29 43.31 0.02 NWT01-VD-016 44.14 44.16 0.02 NWT01-VD-017 45.28 45.31 0.03 NWT01-VD-018 45.72 45.75 0.03 NWT01-VD-019 47.38 47.40 0.02 NWT01-VD-020 48.11 48.13 0.02 NWT01-VD-021 48.60 48.63 0.03 NWT01-VD-022 49.83 49.85 0.02

Notes: This table details the depths and lengths of samples collected for VD analysis.

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Table B4: Summary of results for gas composition analysis

Sample Peak Name (Vol %) Sample ID Depth He H2 Ar O2 N2 CO CO2 C1 C2 C3 iC4 nC4 neopentane iC5 nC5 nC6 (m) NWT01-BLK-001 N/A 94.8207 0.0000 0.0841 1.4179 4.5399 0.0000 0.0036 0.0002 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 NWT01-GC-001 7.81 93.3382 0.0000 0.0941 0.5684 5.6393 0.0000 0.3558 0.0013 0.0002 0.0002 0.0000 0.0001 0.0000 0.0000 0.0000 0.0001 NWT01-GC-002 8.18 93.3382 0.0000 0.0941 0.2434 5.5067 0.0000 0.2635 0.0020 0.0001 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 NWT01-GC-003 8.65 91.3815 0.0000 0.0797 0.7090 6.8754 0.0000 0.3425 0.0022 0.0001 0.0001 0.0001 0.0001 0.0000 0.0000 0.0000 0.0000 NWT01-GC-004 26.07 85.8501 0.0000 0.1815 2.3783 10.8446 0.0000 0.3194 0.0045 0.0005 0.0002 0.0001 0.0001 0.0000 0.0000 0.0000 0.0000 NWT01-GC-005 26.65 88.3230 0.0000 0.1239 1.7133 9.4057 0.0000 0.1168 0.0069 0.0006 0.0003 0.0001 0.0001 0.0000 0.0001 0.0000 0.0000 NWT01-GC-006 26.93 92.5252 0.0000 0.0786 1.1037 5.8436 0.0000 0.1113 0.0018 0.0001 0.0001 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 NWT01-GC-007 28.13 4.5430 0.0000 0.8189 17.5470 75.9390 0.0000 0.1763 0.0026 0.0001 0.0001 0.0002 0.0001 0.0000 0.0000 0.0000 0.0000 NWT01-GC-008 28.43 87.6072 0.0000 0.1307 2.2918 9.2602 0.0000 0.1583 0.0059 0.0005 0.0001 0.0001 0.0001 0.0000 0.0000 0.0001 0.0000 NWT01-GC-009 33.90 90.2498 0.0000 0.1158 1.6437 5.8052 0.0000 1.7371 0.0019 0.0002 0.0001 0.0001 0.0001 0.0000 0.0001 0.0000 0.0000 NWT01-GC-010 34.33 92.3882 0.0000 0.1018 1.2921 4.4927 0.0000 1.6449 0.0063 0.0003 0.0000 0.0001 0.0001 0.0000 0.0000 0.0000 0.0000 NWT01-GC-011 40.67 93.5248 0.0000 0.0675 0.6051 4.9094 0.0000 0.3753 0.0005 0.0002 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 NWT01-GC-012 41.23 93.3804 0.0000 0.0904 0.6381 4.9352 0.0000 0.4544 0.0005 0.0002 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 NWT01-GC-013 41.77 90.7831 0.0000 0.1289 0.5964 7.0927 0.0000 0.6530 0.0003 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 NWT01-GC-014 42.66 92.6252 0.0000 0.0905 0.6491 5.2210 0.0000 0.6138 0.0004 0.0000 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 NWT01-GC-015 43.34 87.4268 0.0000 0.1463 1.0268 10.3488 0.0000 0.3685 0.0005 0.0002 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 NWT01-GC-016 44.18 91.0519 0.0000 0.0916 0.8915 6.8838 0.0000 0.5966 0.0005 0.0002 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 NWT01-GC-017 45.33 92.2875 0.0000 0.0956 0.6111 5.7775 0.0000 0.4908 0.0003 0.0001 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 NWT01-GC-018 45.80 90.0783 0.0000 0.1373 1.0617 7.9273 0.0000 0.2552 0.0004 0.0000 0.0000 0.0000 0.0000 0.0000 0.0001 0.0000 0.0000 NWT01-GC-019 47.41 89.1004 0.0000 0.1317 0.8917 9.4752 0.0000 0.1611 0.0005 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 NWT01-GC-020 48.11 91.1008 0.0000 0.1141 0.9243 6.6715 0.0000 0.4804 0.0004 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 NWT01-GC-021 48.59 90.6176 0.0000 0.1148 0.9199 7.4665 0.0000 0.5687 0.0006 0.0001 0.0000 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 NWT01-GC-022 49.87 91.7901 0.0000 0.1013 0.5363 5.9979 0.0000 0.7872 0.0002 0.0000 0.0000 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 NWT01-GC-023D 41.26 88.7742 0.0000 0.0991 0.9389 8.7142 0.0000 0.4896 0.0005 0.0000 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0001 NWT01-GC-024D 43.34 88.7043 0.0000 0.1226 0.6325 9.3139 0.0000 0.3638 0.0004 0.0002 0.0001 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000

Notes: 1. Gas composition results provided by the University of Calgary Isotope Science Laboratory. The hydrocarbon concentrations were too low for isotope analysis. 2. The table shows all samples analyzed with the relevant volumetric percentages of the different constituents measured shown.

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Table B5: Summary of preliminary results for δ2H, δ18O and δ17O analysis

Sample δ2H δ18O δ17O NWT01-DVE-001 -196.98 -28.11 -15.81 NWT01-DVE-002 -199.75 -29.01 -16.49 NWT01-DVE-003 -199.84 -29.76 -16.46 NWT01-DVE-004 -187.11 -27.02 -15.97 NWT01-DVE-005 -186.35 -27.63 -15.22 NWT01-DVE-006 -196.37 -28.99 -15.91 NWT01-DVE-007 -199.64 -29.44 -16.24 NWT01-DVE-008 -182.49 -21.31 -15.24 NWT01-DVE-009 -174.72 -20.16 -13.91 NWT01-DVE-010 -173.41 -19.90 -13.56 NWT01-DVE-011 -185.97 -21.31 -14.05 NWT01-DVE-012 -203.54 -31.13 -16.73 NWT01-DVE-013 -203.70 -30.43 -16.91 NWT01-DVE-014 -203.75 -31.00 -16.83 NWT01-DVE-015 -205.14 -30.69 -15.78 NWT01-DVE-016 -205.08 -31.02 -16.13 NWT01-DVE-017 -204.48 -30.65 -16.03 NWT01-DVE-018 -205.52 -31.02 -15.87 NWT01-DVE-019 -203.08 -30.30 -17.10 NWT01-DVE-020 -199.58 -30.66 -16.53 NWT01-DVE-021 -205.13 -31.36 -17.01 NWT01-DVE-022 -207.43 -31.54 -16.27 Standards D2H d18O d17O SSRW4 -135.97 -16.65 -8.44 SSRW4 -137.83 -17.39 -9.34 SSRW4 -136.46 -16.93 -8.73

Notes: 1. Table provided by the University of Saskatchewan showing the relevant corrected results for δ2H, δ18O and δ17O for all samples measured and the standards used. 2. It should be noted that these results, as discussed in the text, are likely shifted with respect to the GMWL and LMWL and should not be viewed quantitatively.

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Table B6: Calculated water content of water isotope samples

Sample Wet Weight (g) Dry Weight (g) Water Content (%) NWT01-DVE-001 196.21 184.31 6.46 NWT01-DVE-002 180.18 167.76 7.40 NWT01-DVE-003 47.26 44.62 5.92 NWT01-DVE-004 39.41 38.55 2.23 NWT01-DVE-005 50.72 46.70 8.61 NWT01-DVE-006 34.90 33.02 5.69 NWT01-DVE-007 35.60 33.30 6.91 NWT01-DVE-008 34.05 33.35 2.10 NWT01-DVE-009 30.48 30.13 1.16 NWT01-DVE-010 26.02 25.91 0.42 NWT01-DVE-011 30.74 29.35 4.74 NWT01-DVE-012 41.83 40.07 4.39 NWT01-DVE-013 49.31 47.44 3.94 NWT01-DVE-014 35.60 33.89 5.05 NWT01-DVE-015 45.20 43.42 4.10 NWT01-DVE-016 46.76 44.80 4.38 NWT01-DVE-017 47.56 44.84 6.07 NWT01-DVE-018 35.76 33.71 6.08 NWT01-DVE-019 39.30 37.97 3.50 NWT01-DVE-020 32.63 31.09 4.95 NWT01-DVE-021 38.01 36.69 3.60 NWT01-DVE-022 43.66 40.74 7.17

Average WC 4.77

Notes: Table showing the water content (WC) calculated from the wet and dry weights of the samples, with the highest WC shown in green (8.61%) and the lowest shown in red (0.42%).

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Table B7: Moisture content sample results

Pre-Drying Post-Drying Moisture Content Details Measurements Measurements Total Empty Mass Vial w Start Vial Lost to Mass Sample ID Wet Mass Vial w Current Water Mass Date - Lost/Ini Rock of Rock Mass of Content (g) Mass tial Mass Rock Mass (g) Rock (g) (%) of Mass (g) (g) Water (g) NWT01-An-001 11.947 55.93 43.983 52.909 40.962 3.021 0.0686 6.868 NWT01-An-002 11.941 53.821 41.88 50.445 38.504 3.376 0.0806 8.061 NWT01-An-003 12.002 42.133 30.131 39.645 27.643 2.488 0.0825 8.257 NWT01-An-004 11.949 62.103 50.154 59.13 47.181 2.973 0.0592 5.927 NWT01-An-005 11.968 34.431 22.463 32.388 20.42 2.043 0.0909 9.094 NWT01-An-006 11.944 51.711 39.767 48.494 36.55 3.217 0.0808 8.089 NWT01-An-007 11.961 42.652 30.691 40.243 28.282 2.409 0.0784 7.849 NWT01-An-008 12.018 57.871 45.853 55.064 43.046 2.807 0.0612 6.121 NWT01-An-009 11.929 47.583 35.654 45.437 33.508 2.146 0.0601 6.018 NWT01-An-010 11.985 58.189 46.204 55.404 43.419 2.785 0.0602 6.027 NWT01-An-011 11.947 52.668 40.721 49.785 37.838 2.883 0.0707 7.079 NWT01-An-012 11.981 46.91 34.929 44.583 32.602 2.327 0.0666 6.662 NWT01-An-013 11.977 72.147 60.17 68.54 56.563 3.607 0.0599 5.994 NWT01-An-014 11.943 41.531 29.588 38.337 26.394 3.194 0.1079 10.794 NWT01-An-015 11.989 53.669 41.68 51.41 39.421 2.259 0.0541 5.419 NWT01-An-016 11.939 52.549 40.61 49.823 37.884 2.726 0.0671 6.712 NWT01-An-017 11.987 50.499 38.512 47.989 36.002 2.51 0.0651 6.517 NWT01-An-018 11.959 52.433 40.474 49.239 37.28 3.194 0.0789 7.891 NWT01-An-019 11.973 63.668 51.695 60.964 48.991 2.704 0.0523 5.230 NWT01-An-020 11.992 64.044 52.052 60.144 48.152 3.9 0.0749 7.492 NWT01-An-021 11.928 68.739 56.811 64.939 53.011 3.8 0.0668 6.688 NWT01-An-022 11.973 55.732 43.759 52.195 40.222 3.537 0.0808 8.082

Notes: 1. Samples were prepared on January 31st, 2020. 2. Samples were placed in the oven to start the drying process on February 18th, 2020. 3. Samples were removed from the oven and considered finished drying on July 6th, 2020.

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Figure B1: Cartoon depicting idealized whole core subsampling approach

Schematic showing an idealized core sample and the subsampling protocol that was attempted for each sample. Variations in sample quality and integrity required deviation from this initial plan.

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Figure B2: Cartoon depicting idealized core puck subsampling approach

Schematic showing an idealized subsampled core puck and how it would be broken up before crushing, taking opposite sides of the puck such that sampling bias is minimized.

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Figure B3: Hydraulic press used for rock crushing during sample processing

Image of the rock crushing machine which uses a hydraulic press to crush core samples. The stainless-steel chamber is shown below the piston, with one of the discs sitting in front.

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Figure B4: 18O/2H results plotted against the GMWL, LMWL and LEL

Graph provided by the University of Saskatchewan Hillslope Hydrology Lab showing the δ18O and δ2H results obtained through direct vapour equilibration method (Wassenaar et al., 2008; Hendry et al., 2015). Most samples fall above the GMWL and LMWL but lie along or just below the LEL. Reliability of the method is uncertain due to low sample water contents and is being investigated for method development.

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Appendix C: Inorganic Anion and Cation Analysis (SOP) (F-, Cl-, NO2-, Br-, NO3-, PO4-, SO4=) and (Na+, NH4+, K+, Mg2+, Ca2+)

1. Introduction: This method SOP is applicable for the preparation and determination of inorganic Anions and Cations in Groundwater. It is based on EPA Method 300.1: Determination of Inorganic Anion in Drinking Water by Ion Chromatography.

2. Method Summary: Water samples for analysis by the G360 laboratory are collected using 20 mL plastic vials. The samples for anions are left unpreserved, while cations are preserved with one or two drops of concentrated HCl. This is to drop the pH to less than 2, to keep the Mg and Ca in solution. Sample date and time should be recorded. Samples should be shipped to the lab and upon arrival in the lab the samples will be catalogued with arrival date and time. The samples will then be organized for analysis and stored inverted at 4°C. Samples should be analyzed no later than 14 days after collection. The samples are filtered thru 0.45um syringe filters to remove and particulate matter that may be in solution. The anion and cation samples are then analyzed on dedicated Metrohm Eco IC Plus Ion Chromatographs with dedicated Metrohm 863 IC Autosamplers. The instruments are controlled using Metrohm MagIC data collection software. 3. Reagents: IC standard and calibration checks are prepared from certified standards. IC standards for the calibration curve are prepared from certified 1000 mg/L stock solutions supplied from Sigma Aldrich Canada. The outside calibration standard is purchased from Dionex thru ThermoFisher Scientific. Reagents for mobile phase preparations are purchased from Sigma Aldrich.

4. Equipment/Apparatus: Anions - Metrohm Eco IC Plus and 863 IC autosampler with a 4mm metrosep A Supp4 250 IC column. Cations – Metrohm Eco IC Plus and 863 IC autosampler with a 4mm Metrosep C4 100 IC column.

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5. Health and Safety Precautions: There are no additional precautions required other than those in keeping with G360’s standard laboratory practices and training.

6. Procedure: Water samples should be collected in the field by filling a 20 mL vial in duplicate for analysis. Samples for cations should be preserved with 2 drops of concentrated HCl. The samples should be stored at 4°C and analyzed within 14 days of collection. Remove samples from the refrigerator and allow them to come to room temperature. 10 mL of sample is then filtered thru a 0.45um acetate filter to remove particulate matter. The sample vials are then placed on the sample tray of the 863 IC Autosampler. A 1 mL subsample of the sample is then drawn to flush and fill the Ion Chromatographs 25 uL sample loop. This sample is then injected onto the Ion Chromatograph.

Ion Chromatograph: Analysis of anions and Cations are performed on dedicated Metrohm Eco IC ion chromatographs with an 863 IC autosampler. 20 uL of sample is injected onto a 4 mm Metrohm metrosep A Supp4 IC column for Anions and a 4 mm metrosep C4 100 IC column for Cations. The flow for each IC is 1.0 mL/min. For anions the eluent is 1.8 mM Na2CO3 and 1.7 mM NaHCO3. For Cations unsuppressed IC is done using an eluent consisting of 1.7 mM HNO3 and 0.7 mM Dipicolinic acid. The instrument is controlled, and the resultant data is collected using Metrohm’s MagIC Net software v3.2. QA/QC: Prior to starting analysis, the calibration standards should be run at least once to check to see if the instrument should be recalibrated. The analyzed values should be within 15% of the expected value. Water blanks are analyzed every 10 samples to determine if there are any background levels of the analytes. The blanks should contain no analytes of interest at or above the method detection limit. If this condition is met, then analysis may proceed. After every 10 samples and at the end of the run a continuing calibrations check shall be run. The Data Quality Objective (DQO) for the continuing calibration check standard is 85-115%. At the end of the sample run a second source QC check will be run, to check the calibration curve against an outside source. The DQO for the second source QC standard is 85-115%.

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For Anion and Cation analysis, a laboratory reagent blank comprised of Millipore water (18MΩ) water is prepared in the same way as samples and is analyzed before starting the analysis of any samples. The blank is used to determine if background analytes or interferences are present in the analytical system. Table1: QC operations, frequency, control limits and description of corrective actions. Operation Check Frequency Control Limits Corrective Action Method Blank Before any series of at or below Repeat blank analysis until standards MDL objective met or obtain adequate quality blank water Continuing First, last and every 10 85-115% of Check calibration curve, Calibration Check samples true value prepare new standard. Reanalyse affected samples Duplicate Sample After every 10 samples ≤ 20 RPD Reanalyze samples. Flag data if objective remains unmet. Second Source QC At end of sample set 85-115% Check calibrations. Standard recovery Reanalyze QC standards. If the objective remains unmet determine cause. Recalibrate, reanalyze affected samples if possible.

Field or trip blanks, when provided, are prepared in the same way as the samples. The presence of target analytes in the field or trip blanks should be noted in the analytical report. If the water blanks have met their DQO, no corrective action for the field or trip blanks is required. The Laboratory duplicate samples should be analyzed every ten samples. The acceptance criteria for the lab duplicates is that the two values should be less than 20 relative percent difference (RPD).

[푆푎푚푝푙푒퐶표푛푐(푚푔/퐿) – 퐷푢푝푙푖푐푎푡푒퐶표푛푐(푚푔/퐿)] 푅푃퐷 = × 100 [푆푎푚푝푙푒퐶표푛푐(푚푔/퐿)−퐷푢푝푙푖푐푎푡푒퐶표푛푐(푚푔/퐿)]/2 Field Duplicates from the same set will be analyzed under identical conditions. RPD will be reported for the field duplicates, but no corrective actions will result from the reported RPD values. A quality control anions and cations standard from a source different from the calibration standards should be analyzed within the same sample run. The data quality objective (DQO) for the measured concentrations must be between 85-115% of the expected value.

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Appendix D: NWT01 Strat Log

This figure is initially presented as part of a data montage in Figure 5 of the main text. However, it has been presented here alone to allow for more detailed examination of the NWT01 stratigraphic log.

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Appendix E: Data Tables for Paleodepth Calculations Based on equations outlined in Lin & Bhattacharya (2017) and references therein, several paleohydraulic calculations were undertaken based on bedset thickness measurements completed on several intervals of core (detailed on the next page) from the two fining upward channel fill sequences of the Lower Dunvegan Formation. It is important to note that these formulas are generally derived for application to exposed outcrops instead of core, which results in the values calculated being valuable as a reference only. Additionally, bedset thickness measurements would ideally have been measured on more core intervals, but this was not possible given the core recovery. These calculations state that corrected channel paleodepths would have been on the order of 5.1 m for the Lower Dunvegan Formation in this area. Channel belt widths would have been between 1126.33 m and 1791.18 m, with a channel sinuosity of 1.36 (low-moderate) and a channel slope of 6.69x10-4.

Avg. Run Details Bedset Thickness Channel Bedset Sequence Run Bottom Top thickn # Depth Depth 1 2 3 4 ess 28 40.87 42.09 0.24 Lower Section 29 42.09 43.62 0.18 0.15 0.17 0.27 0.22 - Channel Fill 2 30 43.62 43.92 0.21 31 43.92 44.53 0.32 Lower Section 34 46.97 48.49 0.21 0.17 - Channel Fill 1 35 48.49 50.02 0.18 0.12 Overall Avg. Bedset Thickness 0.205

Unit of Measure Variable Units Notes Bedset thickness from core Sm m Average dune height D m Mean channel depth dm m Channel width wc m For meander streams Channel belt width wcb m Two forms provided Channel sinuosity P - Channel slope S - * Calculated in feet and miles and converted

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Equations References D = Sm*(2.9 +/- 0.7) LeClair & Bridge, 2001 D = dm/8 LeClair & Bridge, 2001 dm = D * 8 LeClair & Bridge, 2001 wc = 8.8*dm^1.82 Bridge & Mackey, 1993 wcb = 59.9*dm^1.8 Bridge & Mackey, 1993 wcb = 192*dm^1.37 Bridge & Mackey, 1993 Lin & Bhattacharya, 2017 and S = 30*(((wc/D)^0.95)/wc^0.98) references therein Lin & Bhattacharya, 2017 and P = 3.5*(wc/D)^-0.27 references therein

Mean Channel Depth Calculations D = 0.205*(2.9 +/- 0.7) D = 0.58 +/- 0.1435 dm = 0.58 (+/- 0.1435) * 8 dm = 4.64 +/- 1.15 m Correction of 10% for compaction dm * 110% = 5.1 +/- 1.3 m

Channel Width Calculations wc = 8.8*(5.104)^1.82 wc = 170.95 m wc = 171 m

Channel Belt Width Calculations wcb = 59.9*(5.104)^1.8 wcb = 192*(5.104)^1.37 wcb = 1126.33 m wcb = 1791.18 m wcb = 1126 m wcb = 1791 m

Channel Sinuosity Calculations P = 3.5*(170.95/5.104)^-0.27 deemed low-moderate P = 1.356 sinuosity

Channel Slope Calculations S = 30*(((170.95/5.104)^0.95)/170.95^0.98) S = 0.000669 S = 6.69E-04

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Appendix F: Text Descriptions of Dunvegan Formation from Historic Data Data collected from Stott (1982), Hayes (2013), the NWT OROGO and the BCOGC database were compiled and their lithologic data was transcribed. These data were used to build stratigraphic logs of numerous well and outcrop sections. Header Details holeID represents the borehole or outcrop ID number. From_m and to_m denotes the top and bottom of the interval described, with all descriptions starting from surface or the shallowest depth and moving to deeper depths. Thickness_m denotes the thickness of the interval Rock_code_Fm denotes the general geologic unit that the interval belongs to. Rock_code_2Package represents whether the interval is part of the Upper Dunvegan (U_DVGN), Lower Dunvegan (L_DVGN), Upper Sully (U_Sully), Fish Scale Member (FSMB), Lower Sully (L_Sully) or Upper Sikanni (U_Sik). Rock_code_3Package represents the same formation details as above, but splits the Lower Dunvegan into the lithostratigraphic framework denoted in this study, with a Lower Dunvegan (L_DVGN) and Middle Shale Layer (M_DVGN). Rock_code_lith denotes the dominant lithology of the interval, with conglomerate (cgl), very coarse sandstone (VC_Ss), coarse sandstone (C_Ss), medium sandstone (M_Ss), fine sandstone (F_Ss), very fine sandstone (VF_Ss), siltstone (Sltst), mudstone (Mdst) and Shale (Shale). Intervals with no recovery are deemed NR. Ranges are also provided (e.g. C_Ss-cgl represents a coarse sandstone to a conglomerate dominated succession) Rock_Description provides a description of the interval noted.

127

holeID from_m to_m thickness_m rock_code_Fm rock_code_2Package rock_code_3Package rock_code_Lith rock_description Conglomerate, massive, brown to grey weathering; showing considerable planar crossbedding; pebbles range from Yi to 6 inches (12.7-152.4 mm); rounded, grey, blue, green, black, white, brown, pink, yellowish brown; quartz, chert, quartzite, quartzitic sands tone, argillite; some beds consist almost entirely of pebbles; some 64_2 0 63.4 63.4 Dunvegan U_Dvgn U_Dvgn Cgl contain a sandstone matrix; well indurated

64_2 63.4 70.7 7.3 Dunvegan U_Dvgn U_Dvgn Shale Mostly covered. Appears to be sandy shale and thin sandstones Partly covered and mostly inaccessible. Sandstone, coarse grained, conglomeratic; massive; layers of conglomerate; some 64_2 70.7 78.3 7.6 Dunvegan U_Dvgn U_Dvgn C_Ss-Cgl crossbedding Conglomerate, grey; massive; grey to brown weathering; some sandy lenses; sandy matrix; shows some crossbedding but mainly massive; slightly finer conglomerate and 64_2 78.3 98.7 20.4 Dunvegan U_Dvgn U_Dvgn Cgl more sandstone toward top Sandstone, coarse grained, conglomerati c; 64_2 98.7 99.6 0.9 Dunvegan U_Dvgn U_Dvgn C_Ss-Cgl crossbedding Conglomerate, grey; massive; grey to brown weathering; some sandy lenses; some large crossbedding; pebbles, K to 3 inches (6.3-76.2 mm); chert, argillite, quartzite; 64_2 99.6 111.8 12.2 Dunvegan U_Dvgn U_Dvgn Cgl black, white, green, blue, pink Covered. Talus indicates that this interval is predominantly sandy shale with some thin, 64_2 111.8 149.9 38.1 Dunvegan L_Dvgn M_Dvgn Shale platy sandstone Sandstone, fine grained, grey, laminated, non-calcareous; thick bedded to massive; brown to brownish grey weathering; some 64_2 149.9 171.5 21.6 Dunvegan L_Dvgn L_Dvgn F_Ss concretions, reddish brown weathering. 64_2 171.5 171.8 0.3 Sully U_Sully U_Sully Shale Shale, silty, brownish grey; platy Sandstone, fine grained, laminated, brownish 64_2 171.8 172.1 0.3 Sully U_Sully U_Sully F_Ss grey; platy 64_2 172.1 172.4 0.3 Sully U_Sully U_Sully Shale Shale, silty; rusty weathering 64_2 172.4 172.7 0.3 Sully U_Sully U_Sully F_Ss Sandstone as above 64_2 172.7 173.3 0.6 Sully U_Sully U_Sully Shale Shale, silty; platy Sandstone, fine grained, laminated, brownish 64_2 173.3 173.6 0.3 Sully U_Sully U_Sully F_Ss grey; platy Mostly covered. Shale, rubbly, rusty weathering 64_2 173.6 183 9.4 Sully U_Sully U_Sully Shale Sandstone, fine grained, laminated, grey; platy 64_2 183 183.9 0.9 Sully U_Sully U_Sully F_Ss to thick bedded 64_2 183.9 189.2 5.3 Sully U_Sully U_Sully Shale Mostly covered. Shale as above Sandstone, fine grained, laminated, grey; platy; 64_2 189.2 189.8 0.6 Sully U_Sully U_Sully F_Ss brownish grey weathering Mostly talus covered. Shale, rubbly, rusty weathering; some orange weathering 64_2 189.8 199.9 10.1 Sully U_Sully U_Sully Shale sideritic concretions Sandstone, argillaceous, fine grained, 64_2 199.9 200.3 0.4 Sully U_Sully U_Sully F_Ss laminated; platy; rusty grey weathering 64_2 200.3 205.5 5.2 Sully U_Sully U_Sully Shale Talus covered. Shale, silty, dark grey 64_2 205.5 214.6 9.1 Sully U_Sully U_Sully NR Covered Shale, rubbly, dark grey to black; mostly talus 64_2 214.6 220.7 6.1 Sully U_Sully U_Sully Shale covered Shale, rubbl y, dark grey to black, rusty weathering; thin beds of argillaceous siltstone and sandstone ; few small sideritic 64_2 220.7 226.8 6.1 Sully U_Sully U_Sully Shale concretions Shale, rubbly, dark grey to black; mostly talus 64_2 226.8 240.5 13.7 Sully U_Sully U_Sully Shale covered. Conglomerate; massive; grey weathering; crossbedded; pebbles, 1 /8 to 3 inches (3.1-76.2 mm), quartz, chert quartzite, argillite, conglomerate, grey, blue, black, 64_4 0 29 29 Dunvegan U_Dvgn U_Dvgn Cgl green, pink Sandstone, coarse grained, conglomeratic; 64_4 29 31.7 2.7 Dunvegan U_Dvgn U_Dvgn C_Ss-Cgl crossbedded; massive; brown weathering Conglomerate; massive; grey weathering; pebbles, 1/8 to 1 1/2 inches 3.1-38.l mm); 64_4 31.7 34.7 3 Dunvegan U_Dvgn U_Dvgn Cgl sandstone matrix Conglomerate; massive; grey weathering; pebbles, 1/8 to 3 inches 64_4 34.7 42.9 8.2 Dunvegan U_Dvgn U_Dvgn Cgl (3.1-76.2 mm); sandstone matrix 64_4 42.9 51.8 8.9 Dunvegan U_Dvgn U_Dvgn NR Covered Conglomerate; massive; grey weathering; pebbles, 1 /8 to 3 inches (3.1-76.2 mm); some 64_4 51.8 70.1 18.3 Dunvegan U_Dvgn U_Dvgn Cgl coarse grained sandstone matrix 64_4 70.1 74.4 4.3 Dunvegan U_Dvgn U_Dvgn F_Ss Covered. Some fine grained sandstone at top

128 Conglomerate and coarse grained sandstone as above; massive; grey weathering; pebbles, 64_4 74.4 84.4 10 Dunvegan U_Dvgn U_Dvgn Cgl 1 /8 to 1 inch (3.1-25.4 mm) Conglomerate and coarse grained sandstone, crosslaminated; crossbedded; massive; grey weatheri ng; pebbles, 1 /8 to 1 inch 64_4 84.4 100.8 16.4 Dunvegan U_Dvgn U_Dvgn Cgl (3.1-25.4 mm) Mostly talus covered. Mudstone and si ltstone, argj llaceous, dark grey; blocky to platy; 64_4 100.8 123.7 22.9 Dunvegan L_Dvgn M_Dvgn Mdst some platy, fine grained sandstone Sandstone, fine grained, grey to brown, laminated; thick bedded to massive; 64_4 123.7 134.1 10.4 Dunvegan L_Dvgn L_Dvgn F_Ss cross bedded. 64_4 134.1 147.8 13.7 Sully U_Sully U_Sully NR Covered Mostly covered. Mudstone, silty, black; rusty 64_4 147.8 160 12.2 Sully U_Sully U_Sully Mdst weathering Shale and sandstone, interbedded; sandstone, 64_4 160 161.5 1.5 Sully U_Sully U_Sully Shale fine gra ined, laminated; platy Mudstone, silty, black; si ltstone layers, 20%; orange weathering concretions. Poorly 64_4 161.5 167.6 6.1 Sully U_Sully U_Sully Mdst exposed 64_4 167.6 182.8 15.2 Sully U_Sully U_Sully Mdst Mostly covered. Mudstone, as below Mudstone, rubbly, dark grey to black; rusty 64_4 182.8 207.2 24.4 Sully U_Sully U_Sully Mdst weather ing; part ly talus covered 64_4 207.2 222.4 15.2 Sully U_Sully U_Sully NR Covered. Conglomerate, grey; massive; crossbedded; some beds with matrix of coarse grained sandstone; pebbles range from Y.i to 5 inches (12.7-127.0 mm) average Y.i to I inch 02.7-25.4 mm); rounded; chert, quartzite, argill ite, conglomerate; red, pink, green, 64_5 0 44.2 44.2 Dunvegan U_Dvgn U_Dvgn Cgl blue, white, black 64_5 44.2 68.6 24.4 Dunvegan U_Dvgn U_Dvgn NR Covered Sandstone, coarse grained to conglomeratiq massive to thick bedded; weathers brown and platy at top; lenses and streaks of 64_5 68.6 74.4 5.8 Dunvegan U_Dvgn U_Dvgn C_Ss-Cgl conglomerate Conglomerate, massive; grey to brown weathering; matrix of coarse grained sandstone; pebbles range from I /8 to 2 inches (3.J -50.8 mm) ave rage about one inch (25.4 mm); chert, quartz, quartzite, argillite; grey, green, pink, blue, black, white; rounded; some alignment of pebbles; 64_5 74.4 81.7 7.3 Dunvegan U_Dvgn U_Dvgn Cgl more sandstone at top 64_5 81.7 107.6 25.9 Dunvegan L_Dvgn M_Dvgn NR Covered Sandstone, fine grained, laminated, grey, crosslaminated; thick bedded to massive; some minor crossbedding; brownish grey 64_5 107.6 117 9.4 Dunvegan L_Dvgn L_Dvgn F_Ss weathering. Poorly exposed. Mudstone with thin beds of 64_5 117 126.1 9.1 Sully U_Sully U_Sully Mdst siltstone and few concretions toward top. Conglomerate, grey, massive; matrix of coarse grai ned sandstone; pebbles l /8 to 2 inches (3 . 1-50.8 mm), some boulders up to 4 inches (10 1.6 mm); pebbles of quartz, chert, quartzite; blue , white, grey, black; partly inaccessible. 65_4 0 24.4 24.4 Dunvegan U_Dvgn U_Dvgn Cgl Approximately Conglomerate, grey, massive; much coarse grained sandstone matrix; pebbles 65_4 24.4 35.1 10.7 Dunvegan U_Dvgn U_Dvgn Cgl 1/4 to 1/2 inch (6.3 -1 2.7 mm), as above Covered. Farther along slope , the lower part of this interval a ppears to be mudstone, siltstone, and few seams of coal or coaly shale. 65_4 35.1 59.5 24.4 Dunvegan U_Dvgn U_Dvgn Mdst The upper half may include conglomerate Conglomerate, grey, massive; much coarse grained sands tone matrix; pebbles, 1/4 to 1 inch (6.3-25.4 mm), average 1/4 to 1/2 inch (6.3-12.7 mm}. Top of t his unit may be somewhat higher as large blocks cover 65_4 59.5 67.1 7.6 Dunvegan U_Dvgn U_Dvgn Cgl slopes Sandstone, coarse grained, grey, conglomeratic , 65_4 67.1 73.2 6.1 Dunvegan U_Dvgn U_Dvgn C_Ss-Cgl massive; pebbles 1/4 to 1/2 inch (6.3-12.7 mm) Conglomerat e, grey, massive; much coarse grained sands tone matrix; pebbles, 1/4 to 4 inches (6.3- 101.6 mm), average 1/2 to 1 inch (12.7-25.4 mm), rounded; quartz, quartzite, chert , argillite; red, green, blue, grey, 65_4 73.2 82.3 9.1 Dunvegan U_Dvgn U_Dvgn Cgl white, black Conglomerate, grey, massive; much coarse 65_4 82.3 88.4 6.1 Dunvegan U_Dvgn U_Dvgn Cgl grained sandstone; pebbles as above 129 Sandstone, coarse grained, conglomeratic, brownish grey, massive; brownish grey weathering; crossbedded and crosslaminated; 65_4 88.4 91.4 3 Dunvegan U_Dvgn U_Dvgn C_Ss-Cgl streaks and lenses of pebbles Conglomerate, grey, massivei much coarse grained sandstone matrix; pebbles as above, 65_4 91.4 94.7 3.3 Dunvegan U_Dvgn U_Dvgn Cgl maximum of 2 inches (50.8 mm) 65_4 94.7 98.3 3.6 Dunvegan U_Dvgn U_Dvgn NR Covered 65_4 98.3 98.9 0.6 Dunvegan U_Dvgn U_Dvgn VF_Ss Sandstone, silty, argil laceous, greeni sh grey, soft 65_4 98.9 101 2.1 Dunvegan U_Dvgn U_Dvgn Mdst Mudstone, very s ilty, olive green, blocky 65_4 101 102.8 1.8 Dunvegan U_Dvgn U_Dvgn Mdst Mudstone, dark grey to black, rubbly to blocky 65_4 102.8 104.6 1.8 Dunvegan U_Dvgn U_Dvgn NR Covered Conglomerate, dark grey t o brown extremely massive; dark grey weathering; pebbles 1/4 to 2 inches (6.3 to 50.8 mm), averaging 1/2 to 1 inch (12.7 to 25.4 mm), rounded; quartz, quartzite, chert, a rgi llite; red, green, blue, grey , white, black; some beds consist entirely of well sorted pebbles, others have 65_4 104.6 120.4 15.8 Dunvegan U_Dvgn U_Dvgn Cgl matrix of coarse grained sandstone 65_4 120.4 129.5 9.1 Dunvegan L_Dvgn M_Dvgn Shale Covered, recessive. Some flaky shale in ta lus Siltstone, sandy argillaceous , lami nated, dark 65_4 129.5 130.7 1.2 Dunvegan L_Dvgn M_Dvgn Sltst olive grey; poorly bedded 65_4 130.7 132.2 1.5 Dunvegan L_Dvgn M_Dvgn NR Covered Mudstone, very sil t y; some beds of argillaceous 65_4 132.2 134.9 2.7 Dunvegan L_Dvgn M_Dvgn Mdst siltstone, olive brown 65_4 134.9 137.9 3 Dunvegan L_Dvgn M_Dvgn Mdst Covered, recessive. Talus of rubbly muds tone Mudstone, silty, dark grey to black, blocky; dark grey weathering; few thin soft concretionary laye rs; some argillaceous 65_4 137.9 142.5 4.6 Dunvegan L_Dvgn M_Dvgn Mdst silts tone at top Siltstone, argillaceous, blocky to flaggy; some interbedded silty mudstone; dark grey 65_4 142.5 147.7 5.2 Dunvegan L_Dvgn M_Dvgn Sltst weathering Sandstone, f ine grained, laminated, grey, sili ceous; some crosslamination; massive to thick bedded; brown weathering; few int ervals of platy sandstone; some 65_4 147.7 158.1 10.4 Dunvegan L_Dvgn L_Dvgn F_Ss co'ncre tionary masses 65_4 158.1 164.5 6.4 Dunvegan L_Dvgn L_Dvgn Shale Covered, recessive . Presumably muds tone Sandstone, fine grained, brownish grey, la minated , calcareous, cherty; massive, becoming thin bedded at top; some cross bedding; light yellow brown 65_4 164.5 169.7 5.2 Dunvegan L_Dvgn L_Dvgn F_Ss weathering; few small concretions. Muds tone, silty, brownish grey, blocky; very sandy at top; some reddish brown 65_4 169.7 170.9 1.2 Sully U_Sully U_Sully Mdst weathering concret ions. Conglomerate, grey, massive; grey weathering; pebbles 1/8 to 1 inch (3.2-25.4 mm), averaging 1/2 inch (12.7 mm), well rounded; 65_6 0 16.8 16.8 Dunvegan U_Dvgn U_Dvgn Cgl coarse grained sandstone matrix Sandstone, coarse grained, massive; grey weathering; some crossbedding and channelling; small pebbles disseminated throughout; 65_6 16.8 20.1 3.3 Dunvegan U_Dvgn U_Dvgn C_Ss-Cgl grades laterally into conglomerate as above 65_6 20.1 31.6 11.5 Dunvegan U_Dvgn U_Dvgn NR Covered Conglomerate, grey, massive; grey weathering; pebbles 1 /8 to 3 inches 3.2-76.2 mm), averaging 1/2 to 1 inch (12.7-25.4 mm); much 65_6 31.6 35.6 4 Dunvegan U_Dvgn U_Dvgn Cgl coarse grained sandstone matrix Sandstone, medium grained, grey, soft to friable, recessive; thick bedded to massive; 65_6 35.6 41.4 5.8 Dunvegan U_Dvgn U_Dvgn M_Ss brown weathering; crossbedded Conglomerate, grey, massive; grey weathering; pebbles 1/8 to 1 inch 3.2-25.4 mm), averaging 1/4 to 1/2 inch (6.3-12.7 mm); much coarse grained sandstone matrix; partly 65_6 41.4 53.6 12.2 Dunvegan U_Dvgn U_Dvgn Cgl inaccessible Conglomerate, grey, massive; grey weathering; pebbles 1/2 to 2 inches (12.7-50.,8 mm), averaging 1 to 1 1/2 inches (25.4-38.1 mm), much coarse 65_6 53.6 57.3 3.7 Dunvegan U_Dvgn U_Dvgn Cgl grained sandstone matrix Conglomerate, as below; pebbles average 1/2 inch (12 .7 mm), some are 2 inches (50.8 mm); 65_6 57.3 61 3.7 Dunvegan U_Dvgn U_Dvgn Cgl much sandstone matrix 65_6 61 63.4 2.4 Dunvegan U_Dvgn U_Dvgn NR Covered

130 Conglomerate, grey, massive; grey weathering; pebbles, well rounded; quartz, quartzite, chert, argillite; 1 /8 to 1 1/2 inch (3.2 to 38.1 mm); averaging 1.4 to 1/2 inch (6.3-12.7); grey, blue, white, green, pink, black; much 65_6 63.4 71.9 8.5 Dunvegan U_Dvgn U_Dvgn Cgl coarse grained sandstone matrix 65_6 71.9 72.8 0.9 Dunvegan U_Dvgn U_Dvgn NR Covered Conglomerate, grey, massive; grey weathering; pebbles 1/4 to 1/2 inch (6.3-12.7 mm); much 65_6 72.8 78.9 6.1 Dunvegan U_Dvgn U_Dvgn Cgl sandstone matrix 65_6 78.9 103.9 25 Dunvegan U_Dvgn U_Dvgn NR Covered Conglomerate, grey, massive; crossbedding; grey weathering; pebbles 1/8 to 1/2 inch (3.2-12.7 mm); averaging 1/4 to 1/2 inch (6.3-12.7 mm) but larger toward top; much 65_6 103.9 118.5 14.6 Dunvegan U_Dvgn U_Dvgn Cgl coarse grained sandstone matrix Covered. May include some conglomerate at 65_6 118.5 155.1 36.6 Dunvegan L_Dvgn M_Dvgn NR top Sandstone, fine grained, laminated, crosslaminated, grey, flaggy to massive; 65_6 155.1 163 7.9 Dunvegan L_Dvgn L_Dvgn F_Ss crossbedded; brown weathering Sandstone, coarse grained, and conglomerate (30%); massive; brown weathering; 65_6 163 170.3 7.3 Dunvegan L_Dvgn L_Dvgn C_Ss-Cgl disseminated pebbles in sandstone Conglomerate, grey, massive; pebbles 1/4 to 1/2 inch (6.3 to 12.7 mm), well sorted and 65_6 170.3 172.4 2.1 Dunvegan L_Dvgn L_Dvgn Cgl rounded; some sandstone matrix Sandstone, medium grained, grey, siliceous, laminated, massive; crossbedded; brown 65_6 172.4 173.6 1.2 Dunvegan L_Dvgn L_Dvgn M_Ss weathering. Conglomerate, massive. Mostly covered to 65_10A 0 91.4 91.4 Dunvegan U_Dvgn U_Dvgn Cgl inaccessible. Approximately Conglomerate, grey, massive; pebbles average 1 inch, (25.4 mm), some are 4 inches (101.6 mm); much sands tone matrix; pebbles consist of quartz , chert, quartzite, rounded to well rounded; blue, grey, white, black, 65_10A 91.4 109.7 18.3 Dunvegan U_Dvgn U_Dvgn Cgl green 65_10A 109.7 147.8 38.1 Dunvegan L_Dvgn M_Dvgn NR Covered sandstone, massive, brown weatheri ng, at top and about I 0 feet (3.O m) . 65_10A 147.8 180.5 32.7 Dunvegan L_Dvgn L_Dvgn F_Ss Inaccessible sands tone in 65_10A 180.5 182.9 2.4 Dunvegan L_Dvgn L_Dvgn F_Ss middle 65_10A 182.9 198.1 15.2 Dunvegan L_Dvgn L_Dvgn Mdst Mudstone; 5-8 feet (1.5-2.4 m), 65_10A 198.1 198.4 0.3 Dunvegan L_Dvgn L_Dvgn Coal Lignite Sandstone, argillaceous at base, becoming cleaner at top, fr iable; mostly not bedded; light grey weathering; some concretionary 65_10A 198.4 221.3 22.9 Dunvegan L_Dvgn L_Dvgn F_Ss zones. Mostly inaccessible. Approximately. Inaccess ible. This interval consists of very silty mudstone elsewhere along slope. 65_10A 221.3 251.7 30.4 Sully U_Sully U_Sully Mdst Approximately Sandstone, fine grained, laminated, grey; poorly bedded; some is thick bedded to massive; 65_10A 251.7 255.4 3.7 Sully U_Sully U_Sully F_Ss concretionary at top Mudstone, blocky; beds of flaggy sandstone, 65_10A 255.4 261.5 6.1 Sully U_Sully U_Sully Mdst (20%). Mostly talus covered Sandstone, fine grained, laminated, crosslaminated; 65_10A 261.5 262.4 0.9 Sully U_Sully U_Sully F_Ss grey weathering; flaggy Shale, black; rusty weat hering; some thin platy 65_10A 262.4 300.5 38.1 Sully U_Sully U_Sully Shale siltstone. Inaccessible or talus covered Shale, black; rusty weathering; thin platy siltstone; 65_10A 300.5 306.6 6.1 Sully U_Sully U_Sully Shale few concretions 65_10A 306.6 312.7 6.1 Sully U_Sully U_Sully NR Covered Sha le, black, flaky to fissile; much yellow 65_10A 312.7 352.3 39.6 Sully FSMB FSMB Shale efflorescence; light grey weathering Shale, black, flaky to fissile; interbedded platy silts tone (3O%). This unit forms seepage horizon, giving dark colour along cliffs. 65_10A 352.3 358.7 6.4 Sully FSMB FSMB Shale Mostly inaccessible Shale, black, flaky to fissile; some interbedded platy siltstone (10% - 15%); light grey 65_10A 358.7 375.5 16.8 Sully FSMB FSMB Shale weathering Shale, black, flaky to fissile; light grey weathering; much yellow efflorescence; 65_10A 375.5 392.3 16.8 Sully FSMB FSMB Shale hard silty bed at top. Mostly inaccessible Mudstone to shale, black, flaky to fissi le; light grey weathering; much yellow 65_10A 392.3 413.6 21.3 Sully FSMB FSMB Mdst efflorescence; hard bed at top

131 Mudstone to shale, black, flaky, soft; grey weathering; yellow efflorescence. Mostly 65_10A 413.6 436.5 22.9 Sully FSMB FSMB Mdst mud and talus covered Mudstone, black, rubbly to blocky; rusty weathering; rows of reddish brown 65_10A 436.5 444.1 7.6 Sully L_Sully L_Sully Mdst weathering concretions 65_10A 444.1 450.2 6.1 Sully L_Sully L_Sully Mdst Mudstone as below. Mostly covered Mudstone, black, rubbly; rusty weathering; few 65_10A 450.2 471.5 21.3 Sully L_Sully L_Sully Mdst reddish brown weathering concretions 65_10A 471.5 474.6 3.1 Sully L_Sully L_Sully Mdst Mudstone as below. Mostly covered Mudstone, black, rubblyj rusty weathering; few 65_10A 474.6 477.6 3 Sully L_Sully L_Sully Mdst thin reddish brown weathering concretions Mudstone, black, rubbly to blocky. Mostly mud 65_10A 477.6 497.4 19.8 Sully L_Sully L_Sully Mdst covered Mudstone, black, rubbly to blocky; grey to rusty weathering; some reddish brown weathering 65_10A 497.4 506.5 9.1 Sully L_Sully L_Sully Mdst concretions Mudstone, soft, black, rubbly. Mostly mud 65_10A 506.5 509.6 3.1 Sully L_Sully L_Sully Mdst covered Mudstone, soft, black, rubbly; grey weathering; 65_10A 509.6 518.7 9.1 Sully L_Sully L_Sully Mdst some concretions in upper part 65_10A 518.7 520.2 1.5 Sully L_Sully L_Sully Mdst Mudstone, black, rubbly. Mostly covered Mudstone, soft, dark brownish grey to black, rubbly; rusty weathering; rare reddish brown 65_10A 520.2 523.3 3.1 Sully L_Sully L_Sully Mdst weathering concretions Mudstone, s il ty, rubbly to blocky; 4 to 5 inches ( 101.6- 127 .0 m) conglomeratic sandstone, channel-fill at base; disseminated pebbles as much as 1 inch (25.4 mm) in diameter; 1 inch (25.4 mm) of fine conglomerate at 65_10A 523.3 523.6 0.3 Sully L_Sully L_Sully Mdst top. 65_10A 523.6 524.6 1 Sikanni U_Sik U_Sik Ss Ss Sandstone, white weathering; poorly bedded; 65_10B 0 4.5 4.5 Dunvegan L_Dvgn L_Dvgn F_Ss coal at top. Inaccessible 65_10B 4.5 9 4.5 Dunvegan L_Dvgn L_Dvgn Mdst Mudstone and interbedded sandstone. Inaccessible Sandstone, fine grained, soft and friable; crossbedded; some conglomerate with pebbles 65_10B 9 13.5 4.5 Dunvegan L_Dvgn L_Dvgn F_Ss-Cgl 1/8 to 1/4 inch (3.1-6.3 mm) 65_10B 13.5 13.8 0.3 Dunvegan L_Dvgn L_Dvgn Coal Coal, sub-bituminous, black Sandstone, fine grained, homogeneous, grey, soft, and friable; poorly bedded; grey 65_10B 13.8 21.1 7.3 Dunvegan L_Dvgn L_Dvgn F_Ss weathering Siltstone, very argillaceous, soft, dark grey; 65_10B 21.1 22.6 1.5 Dunvegan L_Dvgn L_Dvgn Sltst grades into overlying beds Sandstone, grey, very friable and soft, fine grained, laminated, argillaceous; grey 65_10B 22.6 25 2.4 Dunvegan L_Dvgn L_Dvgn F_Ss weathering 65_10B 25 32.6 7.6 Dunvegan L_Dvgn L_Dvgn Mdst Mudstone, very silty, and argillaceous sandstone Sandstone, fine grained, argillaceous, laminated, grey, soft to friable; poorly bedded, 65_10B 32.6 46.6 14 Dunvegan L_Dvgn L_Dvgn F_Ss some beds of mudstone Mudstone, silty; interbedded sandstone, fine 65_10B 46.6 53.6 7 Sully U_Sully U_Sully M grained, laminated, flaggy to thin bedded Sandstone, fine grained, laminated; flaggy to 65_10B 53.6 59.4 5.8 Sully U_Sully U_Sully F_Ss thin bedded Mudstone, very silty, blocky; some interbedded 65_10B 59.4 72.8 13.4 Sully U_Sully U_Sully Mdst sandstone; sandier at top Sandstone, fine grained, laminated, grey; flaggy to thin bedded; grey weathering; some slump 65_10B 72.8 75.2 2.4 Sully U_Sully U_Sully F_Ss structures; some mudstone Mudstone, silty, blocky; rusty to brown weathering; fine grained, laminated sandstone (20%), platy to flaggy; 65_10B 75.2 82.2 7 Sully U_Sully U_Sully Mdst concretions Sandstone, fine grained, laminated, friable, 65_10B 82.2 83.1 0.9 Sully U_Sully U_Sully F_Ss grey; thick bedded; grey weathering Mudstone, rubbly, soft, black to brownish grey; rusty to brown weathering; some thin layers 65_10B 83.1 138.6 55.5 Sully U_Sully U_Sully Mdst of sandstone; concretions Mudstone, black, rubbly to blocky; rusty weathering; sandy beds and 65_10B 138.6 143.4 4.8 Sully U_Sully U_Sully Mdst concretions. Conglomerate, grey, massive; crossbedded; brown to grey weathering; pebbles 1/2 to 65_14 0 4.6 4.6 Dunvegan U_Dvgn U_Dvgn Cgl 1 inch (12.7-25.4 mm) 65_14 4.6 7 2.4 Dunvegan U_Dvgn U_Dvgn NR Covered Sandstone, very coarse grained, to very fine grained conglomerate; massive; brown 65_14 7 14 7 Dunvegan U_Dvgn U_Dvgn VC_Ss-Cgl weathering 65_14 14 15.2 1.2 Dunvegan U_Dvgn U_Dvgn NR Covered 65_14 15.2 18.6 3.4 Dunvegan U_Dvgn U_Dvgn C_Ss-Cgl Sandstone, conglomeratic; massive; crossbedded 65_14 18.6 24.7 6.1 Dunvegan U_Dvgn U_Dvgn NR Covered. Approximately

132 Sandstone, coarse grained to conglomeratic, brown; massive; crossbedded; brown 65_14 24.7 27.7 3 Dunvegan U_Dvgn U_Dvgn C_Ss-Cgl weathering Sandstone, coarse grained; conglomeratic with pebbles as much as 3 inches (76.2 mm); some layers of gravel; becoming finer grained 65_14 27.7 35.3 7.6 Dunvegan U_Dvgn U_Dvgn C_Ss-Cgl toward top; massive; slightly friable Sandstone and conglomerate, partly covered; 65_14 35.3 39 3.7 Dunvegan U_Dvgn U_Dvgn C_Ss-Cgl recessive Conglomerate, grey; massive; crossbedded; pebbles average l inch (25.4 mm), some as 65_14 39 45.1 6.1 Dunvegan U_Dvgn U_Dvgn Cgl much as 4 inches (I01.6 mm) Conglomerate, grey; massive; pebbles average 65_14 45.1 48.1 3 Dunvegan U_Dvgn U_Dvgn Cgl 1/4 inch (6.3 mm); much sandstone matrix Conglomerate, grey; massive; grey weathering; pebbles average 1/2 to 1 inch (12.7-25.4 mm), some as much as 3 inches (76.2 mm); quartz, chert, quartzite; blue, 65_14 48.1 61.8 13.7 Dunvegan U_Dvgn U_Dvgn Cgl grey, black, white, green Siltstone, argillaceous, carbonaceous; platy; 65_14 61.8 63.3 1.5 Dunvegan L_Dvgn M_Dvgn Sltst brown weathering 65_14 63.3 64.5 1.2 Dunvegan L_Dvgn M_Dvgn F_Ss Sandstone, fine grained, brownish grey; massive 65_14 64.5 70.6 6.1 Dunvegan L_Dvgn M_Dvgn Mdst Mudstone. Mostly covered Sandstone, fine grained, laminated, brownish grey; thin to thick bedded; interbedded 65_14 70.6 77.3 6.7 Dunvegan L_Dvgn L_Dvgn F_Ss muds tone, silty, (50%) Sandstone, fine grained, brownish grey, laminated; massive; brown weathering; shaly 65_14 77.3 87.4 10.1 Dunvegan L_Dvgn L_Dvgn F_Ss interval in centre; partly covered at base 65_14 87.4 105.7 18.3 Dunvegan L_Dvgn L_Dvgn NR Covered Conglomerate, grey; massive; grey weathering; pebbles 1 /8 to 1 inch (3.2-25.4 mm); chert, quartz, quartzite; blue, grey, black, white; 65_14 105.7 113.3 7.6 Dunvegan L_Dvgn L_Dvgn Cgl coarse grained sandstone matrix Sandstone, coarse grained, conglomeratic, 65_14 113.3 114.8 1.5 Dunvegan L_Dvgn L_Dvgn C_Ss-Cgl crosslaminated; massive. 65_17 0 10.7 10.7 Dunvegan U_Dvgn U_Dvgn Nr Covered Conglomerate, grey; massive; crossbedded; pebbles average 1/2 inch (12.7 m) but some as much as 3 inches (76.2 mm), rounded; chert, quartzite, quartz, argillite; grey, green, red, blue, black, white; considerable sandstone 65_17 10.7 36.6 25.9 Dunvegan U_Dvgn U_Dvgn Cgl matrix in upper part Sandstone, soft, friab le; flaggy; grades into 65_17 36.6 44.2 7.6 Dunvegan U_Dvgn U_Dvgn C_Ss overlying unit Conglomerate, grey; massive; somewhat 65_17 44.2 64 19.8 Dunvegan U_Dvgn U_Dvgn Cgl recessive 65_17 64 82.3 18.3 Dunvegan U_Dvgn U_Dvgn Mdst Mudstone, not well exposed Conglomerate, grey; massive; brownish grey weathering; crossbedded; pebbles average 1/2 to 1 inch 12.7 to 25.4 mm), some as much as 3 inches (76 .2 mm), rounded; quartz, chert, quartzitei green, grey blue, black 65_17 82.3 102.1 19.8 Dunvegan U_Dvgn U_Dvgn Cgl white Mudstone, brownish grey; thin interbeds of 65_17 102.1 115.8 13.7 Dunvegan L_Dvgn M_Dvgn Mdst silty, concretionary sandstone Sandstone, coarse grained to conglomeratiq massive; dark brown weathering; 65_17 115.8 120.4 4.6 Dunvegan L_Dvgn L_Dvgn C_Ss-Cgl crossbedding Mudstone, dark grey at base, rusty olive weathering at top; interbedded sandstone in 65_17 120.4 126.5 6.1 Dunvegan L_Dvgn L_Dvgn Mdst upper part Sandstone, coarse grained to conglomeratic; massive; dark brown weathering; 65_17 126.5 131.1 4.6 Dunvegan L_Dvgn L_Dvgn C_Ss-Cgl crossbedded 65_17 131.1 135.7 4.6 Dunvegan L_Dvgn L_Dvgn Mdst Muds tone 65_17 135.7 136 0.3 Dunvegan L_Dvgn L_Dvgn Coal Coal, black Sandstone, fine- to medium-grained, friable; poorly bedded; light grey to white weathering; grades downward into 65_17 136 158.9 22.9 Dunvegan L_Dvgn L_Dvgn F-M_Ss underlying beds. 65_17 158.9 159 0.1 Sully U_Sully U_Sully Mdst mudstone, concretionary, mostly covered Conglomerate, grey; massive; pebbles as below, averaging Yi to I inch (12.7-25.4 mm), sandstone 65_18 0 12.8 12.8 Dunvegan U_Dvgn U_Dvgn Cgl matrix Mostly covered. Some mudstone with argillaceous and 65_18 12.8 23.5 10.7 Dunvegan U_Dvgn U_Dvgn Mdst conglomeratic sandstone at base

133 Conglomerate, grey; massive; grey to brown weathering; pebbles 1/8 to 1/2 inch (6.3- 12.7 mm), maximum 1 1/2 inches (38.1 mm); much sandstone matrix; becoming less conglomeratic and sandier at 65_18 23.5 35.7 12.2 Dunvegan U_Dvgn U_Dvgn Cgl top Covered, recessive. Appears to be friable conglomeratic 65_18 35.7 41.5 5.8 Dunvegan U_Dvgn U_Dvgn C_Ss-Cgl sandstone Conglomerate, massive; grey to brown weathering; pebbles average 1/4 to 1/2 inch (6.3-12.7 mm); quartz, quartzite, argillite, chert; white, grey, green, blue, black, red; 65_18 41.5 58.3 16.8 Dunvegan U_Dvgn U_Dvgn Cgl much sandstone matrix Covered. Appears to be mainly conglomerate 65_18 58.3 65.9 7.6 Dunvegan U_Dvgn U_Dvgn Cgl along cl iffs to west Conglomerate, massive; brown weathering; pebbles average 1 1/2 inches (38.1 mm), maximum 6 to 7 inches (152.4-177.8 mm), decreasing in average size toward top; chert, quart zite; quartz, argi llite; white, grey, green, blue, black, red; well washed 65_18 65.9 87.2 21.3 Dunvegan U_Dvgn U_Dvgn Cgl but sandstone matrix increasing toward top Sandstone, very coarse grained to conglomeratic; numerous laminae of pebbles; crossbedded; 65_18 87.2 99.7 12.5 Dunvegan U_Dvgn U_Dvgn VC_Ss-Cgl gravelly 65_18 99.7 105.5 5.8 Dunvegan L_Dvgn M_Dvgn Mdst Mostly covered. Mudstone Mostly covered, recessive. Mudstone with coal 65_18 105.5 110.7 5.2 Dunvegan L_Dvgn M_Dvgn Mdst at top Sandstone, fine grained, grey, lami nated, soft and fri able; crossbedded; massive; grey weathering; 65_18 110.7 115.9 5.2 Dunvegan L_Dvgn L_Dvgn F_Ss weathers recessive 65_18 115.9 141.8 25.9 Dunvegan L_Dvgn L_Dvgn NR Covered Sandstone, fine grained, laminated, grey; massive; crossbedded; grey to light brownish 65_18 141.8 150.9 9.1 Dunvegan L_Dvgn L_Dvgn F_Ss grey weathering 65_18 150.9 158.5 7.6 Dunvegan L_Dvgn L_Dvgn NR Covered Sandstone, fine grained1 grey, laminated; 65_18 158.5 159.7 1.2 Dunvegan L_Dvgn L_Dvgn F_Ss massive; brown weathering. B-055-E/094-O-13 109.7 131.1 21.4 Dunvegan U_Dvgn U_Dvgn cgl inferred from well log B-055-E/094-O-13 131.1 137.2 6.1 Dunvegan U_Dvgn U_Dvgn shale inferred from well log B-055-E/094-O-13 137.2 164.6 27.4 Dunvegan U_Dvgn U_Dvgn cgl inferred from well log B-055-E/094-O-13 164.6 176.8 12.2 Dunvegan U_Dvgn U_Dvgn shale inferred from well log B-055-E/094-O-13 176.8 201.2 24.4 Dunvegan U_Dvgn U_Dvgn cgl inferred from well log B-055-E/094-O-13 201.2 219.5 18.3 Dunvegan U_Dvgn U_Dvgn shale inferred from well log B-055-E/094-O-13 219.5 240.8 21.3 Dunvegan U_Dvgn U_Dvgn cgl inferred from well log B-055-E/094-O-13 240.8 262.1 21.3 Dunvegan L_Dvgn M_Dvgn shale inferred from well log B-055-E/094-O-13 262.1 310.9 48.8 Dunvegan L_Dvgn L_Dvgn cgl inferred from well log B-055-E/094-O-13 310.9 457.2 146.3 Sully U_Sully U_Sully shale inferred from well log B-055-E/094-O-13 457.2 458.1 0.9 Sully U_Sully M_Sully FSM inferred from well log SH, com SS: vf-u f gr, ang-sb ang clr qtzose, mod consol, com qtz overgths, fair to good grn relief, C-066-I/094-O-13 400 402 2 Dunvegan U_Dvgn U_Dvgn Shale TR-COM VIS POR, 4-9% por, 0.05-0.5 to pos 1 md. CONGL: abund chert pebbles and com conglomeratic SS matrix - predom DISSAGG IN SPL; f-predom med-c and vc gr clr & trnsl ang-sb ang qtz grs with com-abund dk CHERT grs/pebs, com attached kao clay - com partially consolidated matrix ctgs with abund OCCLUDING KAO CLAY, com dk PEBS WITH MICRODRUSE SFC - INDICATION OF VOIDS and TR VISIBLE POR, INFER 6-9 TO POS 10-12% POR, 0.05-0.5 mD to streaky 1-3 md to pos 5-10+ mD. PREDOM DISSAGGREGATED IN SPL CONGL: as abv, increase in com vis por, EX C-066-I/094-O-13 402 420 18 Dunvegan U_Dvgn U_Dvgn Cgl POR/PERM, 5-10 TO POS 50+ MD C-066-I/094-O-13 420 421 1 Dunvegan U_Dvgn U_Dvgn Shale SH, lot brn MUSTONE, com SLTST. C-066-I/094-O-13 421 421.5 0.5 Dunvegan U_Dvgn U_Dvgn Sltst C-066-I/094-O-13 421.5 422.5 1 Dunvegan U_Dvgn U_Dvgn Shale C-066-I/094-O-13 422.5 423.5 1 Dunvegan U_Dvgn U_Dvgn Sltst C-066-I/094-O-13 423.5 427 3.5 Dunvegan U_Dvgn U_Dvgn Shale

134 SS: conglomeratic, f-u c clr qtz gr with com dk gy & blk CHT grs/pebs, tr-com u c-l vc gr ang-sb ang & com sb rdd qtz & chert pebs, tr micro druse on qtz/cht, PREDOM DISSAGG in spl, ABUND KAO CLAY - ONLY RR VIS POR OBSERVED IN partially consolidated ctgs, INFER FAIR-POOR RESERVOIR QUALITY (? DUE TO DISSAGG NATURE OF SPL, 5-8% predom micro por, <0.5 md (?), 435 spl; ABUND VARICOL CHERT, PREDOM DK CHT pebbles, predom DISSAGG in spl, COM SS MATRIX: vf-c gr, ang clr qtz grs with com chert, comly loosely attached to pebble surface with EX POR/PERM 7-9 to pos 14% +, 1-5 to pos 10-100+ md., CONGL: abund varicoloured LOOSE CHERT PEBBLES with com SS matrix: f-l med gr to com l c gr, ang-sb ang clr qtz grs, predom DISSAGG in spl, LITTLE CONSOL material with tr KAO CLAY with COM VIS POR, infer9-12 or 14% por, 1-10 TO POS 10-100 mD +, ? DUE TO C-066-I/094-O-13 427 462 35 Dunvegan U_Dvgn U_Dvgn Cgl DISSAGG NATURE OF SAMPLES C-066-I/094-O-13 462 466.5 4.5 Dunvegan U_Dvgn U_Dvgn Shale SH, SLTY grading to argillaceous SLTST. C-066-I/094-O-13 466.5 468 1.5 Dunvegan U_Dvgn U_Dvgn Sltst C-066-I/094-O-13 468 469 1 Dunvegan U_Dvgn U_Dvgn Shale C-066-I/094-O-13 469 470 1 Dunvegan U_Dvgn U_Dvgn Sltst C-066-I/094-O-13 470 472.5 2.5 Dunvegan U_Dvgn U_Dvgn Shale SS: vf-u f gr, com l med gr, clr angular QTZ grs, almost wholly DISSAGG in spl, com partially consolidated ctgs with abund occluding KAO clay, INFER POOR C-066-I/094-O-13 472.5 475 2.5 Dunvegan U_Dvgn U_Dvgn VF-F_Ss POR/PERM, 3-6% predom micro clay por, <0.03 md. C-066-I/094-O-13 475 476 1 Dunvegan U_Dvgn U_Dvgn Shale SH, SLTY grading to argillaceous SLTST. CONGL: appears similar to abv, abund varicol CHERT PEBBLES, COM QTZ grs/pebs, com NON-SUPPORTING SS MATRIX; vf-med an c gr, ang clr qtz grs with com overths, TR-COM VIS POR in matrix cmt'd to peb sfc, C-066-I/094-O-13 476 487.5 11.5 Dunvegan U_Dvgn U_Dvgn Cgl INFER GOOD POR/PERM, 5-9% por, 1-5 md + 490 spl, INCR IN SHALE/SILTSTONE, abund chert C-066-I/094-O-13 487.5 488 0.5 Dunvegan U_Dvgn U_Dvgn Shale pebs/ss matrix C-066-I/094-O-13 488 489.5 1.5 Dunvegan U_Dvgn U_Dvgn Sltst C-066-I/094-O-13 489.5 490.5 1 Dunvegan U_Dvgn U_Dvgn Shale C-066-I/094-O-13 490.5 492 1.5 Dunvegan U_Dvgn U_Dvgn Sltst C-066-I/094-O-13 492 493.5 1.5 Dunvegan U_Dvgn U_Dvgn Shale C-066-I/094-O-13 493.5 494.5 1 Dunvegan U_Dvgn U_Dvgn VF_Ss SH, com SLTST, com sltst -vf gr ss, arg, rr-tr vis por. C-066-I/094-O-13 494.5 495 0.5 Dunvegan U_Dvgn U_Dvgn Sltst C-066-I/094-O-13 495 497 2 Dunvegan U_Dvgn U_Dvgn Shale SH, com SS: vf-l f gr, trnsl wh qtz grs with tr carb mat, C-066-I/094-O-13 497 498 1 Dunvegan U_Dvgn U_Dvgn VF-F_Ss mica, KAO clay plugged, NO VIS POR. C-066-I/094-O-13 498 498.5 0.5 Dunvegan U_Sully U_Dvgn sltst C-066-I/094-O-13 498.5 499 0.5 Dunvegan U_Dvgn U_Dvgn Shale C-066-I/094-O-13 499 499.5 0.5 Dunvegan U_Dvgn U_Dvgn VF-F_Ss C-066-I/094-O-13 499.5 500.5 1 Dunvegan U_Dvgn U_Dvgn Shal SH, com SLTST grading to vf gr SS: SIL, SLTY, SIL, C-066-I/094-O-13 500.5 501 0.5 Dunvegan U_Dvgn U_Dvgn Sltst CARB, no vis por. C-066-I/094-O-13 501 503 2 Dunvegan U_Dvgn U_Dvgn VF_Ss C-066-I/094-O-13 503 505.5 2.5 Dunvegan U_Dvgn U_Dvgn Shale CONGL: abund loose varicol chert pebbles with com attached & unattached SS matrix: vf-c & vc gr, com clr qtz overgths and cmt with TR-COM VIS POR, 4-8 or 9% por, 1-3 to pos 5+ md ? due to dissagg nature of spl, CONGL: predom dissagg in spl, COM consol ctg with COM VIS POR, com occluding and partially occluding C-066-I/094-O-13 505.5 530.5 25 Dunvegan U_Dvgn U_Dvgn Cgl KAO clay, 5-9 TO POS 12% POR, 1-3 TO POS 5-50 mD. SH, abund MUSTONE, SH, com SLTST, com SS: vf gr, sitly, kao, NO C-066-I/094-O-13 530.5 534 3.5 Dunvegan L_Dvgn M_Dvgn Shale VIS POR. C-066-I/094-O-13 534 535 1 Dunvegan L_Dvgn M_Dvgn Sltst C-066-I/094-O-13 535 535.5 0.5 Dunvegan L_Dvgn M_Dvgn Shale C-066-I/094-O-13 535.5 536 0.5 Dunvegan L_Dvgn M_Dvgn Sltst C-066-I/094-O-13 536 541.5 5.5 Dunvegan L_Dvgn M_Dvgn Shale C-066-I/094-O-13 541.5 542 0.5 Dunvegan L_Dvgn M_Dvgn Sltst C-066-I/094-O-13 542 543.5 1.5 Dunvegan L_Dvgn M_Dvgn VF_Ss C-066-I/094-O-13 543.5 545.5 2 Dunvegan L_Dvgn M_Dvgn Shale 550 CONGL: abund varicol CHT pebbles with com f-c gr SS matrix: vf-med gr ang weakly consol qtz grs with COM VIS POR in few consol ctgs, 6-9 TO POS >, 0.5-1 TO POS 1-5 MD + ? DUE TO DISSAGG NATRUE OF SPL, com SS: silt-vf gr, carb, kao, NO VIS POR, 1-3% micro C-066-I/094-O-13 545.5 548.5 3 Dunvegan L_Dvgn L_Dvgn Cgl clay por, <0.02 md C-066-I/094-O-13 548.5 549.5 1 Dunvegan L_Dvgn L_Dvgn F-C_Ss 555 SH, com lt gy CLAYST, com SS: silt-lf gr, tr carb mat, v kaolinitic, NO VIS POR., 560 SH, com SS: vf-l f gr, ang wh fros qtz grs, rr chert, C-066-I/094-O-13 549.5 553 3.5 Dunvegan L_Dvgn L_Dvgn Shale rr CARB mat, abund occluding KAO clay, NO VIS POR. C-066-I/094-O-13 553 554.5 1.5 Dunvegan L_Dvgn L_Dvgn VF-F_Ss C-066-I/094-O-13 554.5 556 1.5 Dunvegan L_Dvgn L_Dvgn Shale

135 565 SS: as abv, vf-l med gr, gr ang-sb ang clr & fros qtz grs with 2% carb grs, com qtz overgths, occluding KAO C-066-I/094-O-13 556 570 14 Dunvegan L_Dvgn L_Dvgn VF-M_Ss clay, NO VIS POR. C-066-I/094-O-13 570 570.5 0.5 Sully U_Sully U_Sully Shale SH, SILTST, com vf-f gr SS, sil, kao, NO VIS POR. C-066-I/094-O-13 570.5 571 0.5 Sully U_Sully U_Sully VF-F_Ss C-066-I/094-O-13 571 571.5 0.5 Sully U_Sully U_Sully Shale C-066-I/094-O-13 571.5 572 0.5 Sully U_Sully U_Sully VF-F_Ss C-066-I/094-O-13 572 573 1 Sully U_Sully U_Sully Shale C-066-I/094-O-13 573 575 2 Sully U_Sully U_Sully Sltst C-066-I/094-O-13 575 576 1 Sully U_Sully U_Sully Shale SH, com sltst/ss as abv. C-066-I/094-O-13 576 577 1 Sully U_Sully U_Sully VF-F_Ss C-066-I/094-O-13 577 578 1 Sully U_Sully U_Sully Shale C-066-I/094-O-13 578 579.5 1.5 Sully U_Sully U_Sully Sltst C-066-I/094-O-13 579.5 580.5 1 Sully U_Sully U_Sully Shale C-066-I/094-O-13 580.5 581.5 1 Sully U_Sully U_Sully Sltst SH,com argillaceous SLTST C-066-I/094-O-13 581.5 582.5 1 Sully U_Sully U_Sully Shale C-066-I/094-O-13 582.5 584.5 2 Sully U_Sully U_Sully Sltst C-066-I/094-O-13 584.5 586 1.5 Sully U_Sully U_Sully Shale C-066-I/094-O-13 586 588 2 Sully U_Sully U_Sully Sltst SH, com argillaceous SLTST. C-066-I/094-O-13 588 588.5 0.5 Sully U_Sully U_Sully Shale C-066-I/094-O-13 588.5 589 0.5 Sully U_Sully U_Sully Sltst C-066-I/094-O-13 589 590.5 1.5 Sully U_Sully U_Sully Shale SH, mnr-com argillaceous SLTST. C-066-I/094-O-13 590.5 591 0.5 Sully U_Sully U_Sully Sltst C-066-I/094-O-13 591 591.5 0.5 Sully U_Sully U_Sully Shale C-066-I/094-O-13 591.5 593.5 2 Sully U_Sully U_Sully Sltst C-066-I/094-O-13 593.5 596.5 3 Sully U_Sully U_Sully Shale SH, com argillaceous SLTST. C-066-I/094-O-13 596.5 597.5 1 Sully U_Sully U_Sully Sltst C-066-I/094-O-13 597.5 599 1.5 Sully U_Sully U_Sully Shale C-066-I/094-O-13 599 599.5 0.5 Sully U_Sully U_Sully Sltst SH, com argillaceous SLTST grading to l vf gr SS, sil, tr C-066-I/094-O-13 599.5 602.5 3 Sully U_Sully U_Sully Shale carb mat, no vis por. C-066-I/094-O-13 602.5 604.5 2 Sully U_Sully U_Sully Sltst C-066-I/094-O-13 604.5 607 2.5 Sully U_Sully U_Sully Shale D-075-E/094-N-08 6.1 7 0.9 Dunvegan U_Dvgn U_Dvgn cgl inferred from well log D-075-E/094-N-08 170.7 171.6 0.9 Sully U_Sully U_Sully shale inferred from well log D-075-E/094-N-08 390.1 391.1 1 Sully U_Sully M_Sully FSM inferred from well log D-075-E/094-N-08 411.5 412.4 0.9 Sikanni U_Sik U_Sik ss inferred from well log A-077-D/094-O-11 320 368.8 48.8 Dunvegan U_Dvgn U_Dvgn Cgl inferred from well log A-077-D/094-O-11 368.8 374.9 6.1 Dunvegan U_Dvgn U_Dvgn Shale inferred from well log A-077-D/094-O-11 374.9 394.7 19.8 Dunvegan U_Dvgn U_Dvgn Cgl inferred from well log A-077-D/094-O-11 394.7 399.3 4.6 Dunvegan U_Dvgn U_Dvgn Shale inferred from well log A-077-D/094-O-11 399.3 400.8 1.5 Dunvegan U_Dvgn U_Dvgn Ss inferred from well log A-077-D/094-O-11 400.8 406.9 6.1 Dunvegan U_Dvgn U_Dvgn Shale inferred from well log A-077-D/094-O-11 406.9 410 3.1 Dunvegan U_Dvgn U_Dvgn Ss inferred from well log A-077-D/094-O-11 410 420.6 10.6 Dunvegan U_Dvgn U_Dvgn Shale inferred from well log A-077-D/094-O-11 420.6 423.7 3.1 Dunvegan U_Dvgn U_Dvgn Ss inferred from well log A-077-D/094-O-11 423.7 429.8 6.1 Dunvegan U_Dvgn U_Dvgn Shale inferred from well log A-077-D/094-O-11 429.8 432.8 3 Dunvegan U_Dvgn U_Dvgn Ss inferred from well log A-077-D/094-O-11 432.8 437.4 4.6 Dunvegan U_Dvgn U_Dvgn Shale inferred from well log A-077-D/094-O-11 437.4 438.9 1.5 Dunvegan U_Dvgn U_Dvgn Ss inferred from well log A-077-D/094-O-11 438.9 445 6.1 Dunvegan U_Dvgn U_Dvgn Shale inferred from well log A-077-D/094-O-11 445 458.7 13.7 Dunvegan U_Dvgn U_Dvgn Cgl inferred from well log A-077-D/094-O-11 458.7 460.2 1.5 Dunvegan U_Dvgn U_Dvgn Shale inferred from well log A-077-D/094-O-11 460.2 484.6 24.4 Dunvegan U_Dvgn U_Dvgn Cgl inferred from well log A-077-D/094-O-11 484.6 496.8 12.2 Dunvegan L_Dvgn M_Dvgn Shale inferred from well log A-077-D/094-O-11 496.8 509 12.2 Dunvegan L_Dvgn L_Dvgn Cgl inferred from well log A-077-D/094-O-11 509 510.5 1.5 Dunvegan L_Dvgn L_Dvgn Shale inferred from well log A-077-D/094-O-11 510.5 524.3 13.8 Dunvegan L_Dvgn L_Dvgn Ss inferred from well log A-077-D/094-O-11 524.3 670.6 146.3 Sully U_Sully U_Sully Shale inferred from well log A-077-D/094-O-11 685.5 686.7 1.2 Sully U_Sully U_Sully FSM inferred from well log A-026-B/094-O-11 97.5 161.5 64 Dunvegan U_Dvgn U_Dvgn Cgl inferred from well log A-026-B/094-O-11 161.5 167.6 6.1 Dunvegan U_Dvgn U_Dvgn Shale inferred from well log A-026-B/094-O-11 167.6 189 21.4 Dunvegan U_Dvgn U_Dvgn Cgl inferred from well log A-026-B/094-O-11 189 198.1 9.1 Dunvegan U_Dvgn U_Dvgn Shale inferred from well log A-026-B/094-O-11 198.1 199.6 1.5 Dunvegan U_Dvgn U_Dvgn Ss inferred from well log A-026-B/094-O-11 199.6 204.2 4.6 Dunvegan U_Dvgn U_Dvgn Shale inferred from well log A-026-B/094-O-11 204.2 207.3 3.1 Dunvegan U_Dvgn U_Dvgn Ss inferred from well log A-026-B/094-O-11 207.3 216.4 9.1 Dunvegan U_Dvgn U_Dvgn Shale inferred from well log A-026-B/094-O-11 216.4 219.5 3.1 Dunvegan U_Dvgn U_Dvgn Ss inferred from well log A-026-B/094-O-11 219.5 221 1.5 Dunvegan U_Dvgn U_Dvgn Shale inferred from well log A-026-B/094-O-11 221 224 3 Dunvegan U_Dvgn U_Dvgn Ss inferred from well log A-026-B/094-O-11 224 228.6 4.6 Dunvegan U_Dvgn U_Dvgn Shale inferred from well log A-026-B/094-O-11 228.6 253 24.4 Dunvegan U_Dvgn U_Dvgn Cgl inferred from well log A-026-B/094-O-11 253 259.1 6.1 Dunvegan U_Dvgn U_Dvgn Shale inferred from well log A-026-B/094-O-11 259.1 274.3 15.2 Dunvegan U_Dvgn U_Dvgn Cgl inferred from well log A-026-B/094-O-11 274.3 277.4 3.1 Dunvegan L_Dvgn M_Dvgn Shale inferred from well log A-026-B/094-O-11 277.4 289.6 12.2 Dunvegan L_Dvgn M_Dvgn Ss inferred from well log A-026-B/094-O-11 289.6 292.6 3 Dunvegan L_Dvgn M_Dvgn Shale inferred from well log A-026-B/094-O-11 292.6 295.7 3.1 Dunvegan L_Dvgn L_Dvgn Cgl inferred from well log A-026-B/094-O-11 295.7 298.7 3 Dunvegan L_Dvgn L_Dvgn Shale inferred from well log A-026-B/094-O-11 298.7 313.9 15.2 Dunvegan L_Dvgn L_Dvgn Ss inferred from well log A-026-B/094-O-11 313.9 472.1 158.2 Sully U_Sully L_Dvgn Shale inferred from well log

136 A-026-B/094-O-11 472.1 473.4 1.3 Sully U_Sully U_Sully FSM inferred from well log SANDSTONE: salt and pepper, predominantly fine to coarse grained, minor very fine and very coarse grains, trace pebble fragments, sublitharenite with abundant frosted to clear to locally ferruginous stained quartz and common dark to light varicolored lithic grains, moderately sorted, angular to subrOlmded to minor rounded, minor consolidated cuttings with common patchy kaoliniti~ and spotty siliceous cement, minor to common quartz overgrowths, locally patchy ferruginous stain, infer good I-46 16 21 5 Dunvegan U_Dvgn U_Dvgn F-C_Ss to streaky fair porosity, no shows. CONGLOMERATE: disaggregated, predominantly fine pebble, clast supported, polymict with abundant light to dark varicolored very siliceous to silicified predominantly aphanitic volcanic and metasedimentary clasts, common white to clear to occasionally varicolored quartz clasts, trace schistose metamorphic and sandstone clasts, rounded to sub angular, poorly sorted, matrix: very fine to coarse grained sandstone as above, trace spotty kaolinitic and siliceous cement on clasts, trace patchy ferruginous stain, infer predominantly good to excellent porosity, no I-46 21 30 9 Dunvegan U_Dvgn U_Dvgn Cgl shows. SANDSTONE: orange to mottled orange white, fine to very coarse grained, pebbly, litharenite to sublitharenite with abundant quartz and common to abundant varicolored lithic grains to clasts as previously described, moderately poorly to moderately sorted, angular to rounded, commonly disaggregated in part, common poorly to moderately indurated consolidated cuttings with abundant limonitic cement &lor matrix, locally common to abundant patchy kaolin, minor hematitic stain and crusts on grains, infer tight in part with streaky to patchy fair to good porosity, no I-46 30 35 5 Dunvegan U_Dvgn U_Dvgn F-VC_Ss-Cgl shows.

SANDSTONE and CONGLOMERATE:: predominantly as described from 16-30m, infer thinly interbedded with variable streaky fair to good porosity, minor interbedded SANDSTONE: #2 light to medium grey, salt and pepper, very fine grained, quartzolithic; variably silty and argillaceous with slightly bentonite matrix, slightly tuffaceous with common scattered mica, tight, no shows, trace siltstone stringers; medium to dark grey, very argillaceous, slightly sandy, poorly to moderately I-46 35 40 5 Dunvegan U_Dvgn U_Dvgn VF-VC_Ss-Cgl indurated, tight, no shows, grades to silty bentonitic shale in part. SANDSTONE: predominantly as above, trace SANDSTONE: #2 as above, minor to common interbedded SILTSTONE: light grey to light brown, quartzose, predominantly variably argillaceous, minor scattered carbonaceous debris and mica, poorly to moderately indurated, grades to very silty shale in part, locally sandy occasionally grading to silty sandstone laminations, minor thin interbedded SHALE: light grey, finn, sub platy to sub blocky, sub fissile, commonly variably silty and micromicaceous, locally common carbonaceous specks, slightly bentonitic, sub waxy I-46 40 50 10 Dunvegan U_Dvgn U_Dvgn Shale-VC_Ss in part grading to claystone.

137 SANDSTONE with Interbedded SILTSTON1E and minor SHALE: SANDSTONE: unconsolidated to disaggregated, fine to coarse grained, minor very fine and very coarse grains, occasional pebble, litharenite grading to sublitharenite, abundant clear to frosted quartz with common varicolored lithic grains, minor rounded brown sideritic grains, moderately sorted, angular to subrounded, trace consolidated cuttings with spotty siliceous and kaolinitic cement, infer good porosity, no shows; SILTSTONE: light to medium grey, quartzose, common scattered mica and carbonaceous specks, commonly variably argillaceous to locally clean, poorly indurated, tight, no shows; SHALE: dark grey, firm, sub platy to sub blocky, predominantly variably silty, common scattered carbonaceous debris and occasional coaly partings and laminations, I-46 50 65 15 Dunvegan U_Dvgn U_Dvgn Shale-C_Ss-Cgl minor interbedded claystone. SANDSTONE: off white, salt and pepper, very fine to medium grained, trace coarse grains, sublitharenite, abundant clear to frosted quartz and common varicolored lithic grains, trace mic~ moderately to moderately well sorted, angular to sub angular, predominantly disaggregated, minor consolidated cuttings with common spotty to patchy kaolinitic cement, trace spotty siliceous cement and quartz overgrowths, infer I-46 65 70.5 5.5 Dunvegan U_Dvgn U_Dvgn VF-M_Ss streaky fair to good porosity, no shows. SILTSTONE with interbedded eLAYSTONE: SILTSTONE: light to medium grey, quartzose, common scattered mica, minor carbonaceous specks, poorly to moderately indurated with siliceous cement in part, commonly variably argillaceous, locally sandy grading to very fine sandstone stringers, tight, no shows; CLAYSTONE: predominantly light grey, finn to locally soft, brittle in part, sub waxy, variably silty in part occasionally grading to argilla.ceous siltstone laminations, I-46 70.5 75.5 5 Dunvegan L_Dvgn M_Dvgn Mdst-Sltst locally very carbonaceous to coaly, trace sideritic laminations. SILTSTONE with minor interbedded SHALE: SILTSTONE: medium brown to orange brown, quartzose, micaceous, minor carbonaceous specks, moderately to poorly indurated, predominantly variably argillaceous grading to silty shale in part, common to abundant ferruginous stain, tight, no shows; SHALE: as above becoming increasingly micromicaceous, trace maroon claystone I-46 75.5 80 4.5 Dunvegan L_Dvgn M_Dvgn Mdst-Sltst stringers. SANDSTONE with interbedded SHALE: SANDSTONE: very light grey to offwhite, salt and pepper, fine to medium grained, sublitharenite, abundant frosted to clear quartz with common varicolored lithic grains, rare glauconite, moderately to moderately well sorted, angular to subrounded, commonly disaggregated, minor consolidated cuttings with common to abundant patchy kaolin, minor locally common calcareous cement, infer predominantly poor porosity, no shows; SHALE: light to medium grey, firm, sub blocky, predominantly very silty grading to I-46 80 84 4 Dunvegan L_Dvgn L_Dvgn Shale-F-M_Ss argillaceous siltstone in part.

138 SANDSTONE with interbedded SILTSTONE and SHALE: SANDSTONE: unconsolidated to disaggregated, fine to medium grained, minor very fine and coarse grains, trace very coarse grains, litharenite with abundant clear to frosted to occasionally varicolored quartz and common to abundant varicolored lithic grains, moderately sorted, angular to subrounded, trace consolidated cuttings with spotty to patchy kaolinitic and siliceous cement, minor quartz overgrowths, infer streaky fair to good porosity, no shows; I-46 84 89.5 5.5 Dunvegan L_Dvgn L_Dvgn Shale-F-M_Ss SHALE and SILTSTONE: similar to above. SANDSTONE: offwhite to light grey, predominantly fine grained, minor very fine and med\um grains, sublitharenite grading to litharenite, abundant frosted to clear quartz anci,commol1 varicolored lithic grains, trace rounded brown sideritic grains, well sorted;'angular to subrounded, disaggregated in part, common consolidated cuttings abun\iant tight calcareous cement, trace to minor spotty kaolin, tight to I-46 89.5 95 5.5 Dunvegan L_Dvgn L_Dvgn F_Ss streaky poor llorosity, no shows. SANDSTONE: light to medium grey, very fme grained, quartzolithic, rare glauconite, commonly variably micaceous, well sorted, angular to sub angular, moderately to poorly indurated with locally common dolomitic cement, commonly variably silty grading to sandy siltstone in part, clean to locally argillaceous, tight to I-46 95 100 5 Dunvegan L_Dvgn L_Dvgn VF_Ss poor porosity, no shows. SHALE/CLAYSTONE with minor interbedded SILTSTONE: SHALE: dark grey, sub platy, firm, commonly variably silty and micromicaceous, common carbonaceous to coaly debris and partings, trace to minor coaly stringers, CLAYSTONE: light to medium grey, brown, sub blocky, smooth to locally silty, I-46 100 106 6 Dunvegan L_Dvgn L_Dvgn Shale-Sltst carbonaceous to coaly in part, SILTSTONE: as above.

SANDSTONE: offwhite, predominantly fine grained, minor very fine and medium grains, sublitharenite, abundant white to frosted to minor clear quartz with minor to common varicolored lithic grains, well sorted, angular to sub angular, disaggregated in minor part, moderately to moderately poorly indurated with abundant tight calcareous I-46 106 110 4 Dunvegan L_Dvgn L_Dvgn F_Ss cement, tight, no shows, minor thin interbedded shale as above. SANDSTONE with minor interbedded SHALE and SILTSTONE: SANDSTONE: as above becoming predominantly fine to medium grained, becomes commonly disaggregated with decreasing minor to common consolidated cuttings as previously described, moderately well sorted, infer common tight to poor porosity with minor fair streaks, no shows; I-46 110 119 9 Dunvegan L_Dvgn L_Dvgn Shale-F-M_Ss SHALE and SILTSTONE: as previously described. SHALE: medium grey, firm, brittle in part, sub blocky to blocky, predominantly silty and micromicaceous occasionally grading to argillaceous siltstone stringers to laminations, minor locally common carbonaceous debris and partings, trace hard I-46 119 122.5 3.5 Dunvegan L_Dvgn L_Dvgn Shale brown sideritic stringers. SANDSTONE: white, predominantly fine grained, minor lower medium and trace upper very fine grains, sublitharenite with abundant clear to frosted quartz and minor predominantly light varicolored lithic grains, tuffaceous texture with common biotite and spotty bentonitic clay matrix, well sorted, angular to subrounded, commonly disaggregated, minor to common consolidated cuttings with minor locally common calcareous cement, infer common poor porosity with minor fair to good streaks, no shows, minor pale blue white tuffaceous bentonite stringers, trace siltstone I-46 122.5 130 7.5 Dunvegan L_Dvgn L_Dvgn F_Ss stringers. 139 SANDSTONE: white, salt and pepper, very fine to medium grained, Iitharenite grading to sublitharenite, abundant frosted to clear quartz with common dark to light varicolored lithic grains, trace sideritic grains and mica, moderately well sorted, angular to subrounded, predominantly disaggregated, minor consolidated cuttings with spotty kaolinitic and siliceous cement, minor locally common calcareous cement, trace quartz overgrowths, infer fair to good poro~ity, no shows, trace to minor interbedded SILTSTONE: medium grey, quartzose, micaceous, commonly variably argillaceous, I-46 130 145 15 Dunvegan L_Dvgn L_Dvgn Sltst-VF-M_Ss trace scattered carbonaceous debris, minor shaly laminations. SANDSTONE: similar to above, unconsolidated to disaggregated, salt and pepper, very fine to medium grained, litharenite grading to sublitharenite, abundant frosted to clear quartz with common varicolored lithic grains, trace biotite, rare glauconite, moderately well sorted, angular to subrounded, trace consolidated cuttings with spotty kaolin, minor calcareous cement, infer good to streaky fair porosity, no shows, minor interbedded SILTSTONE: medium grey, quartzolithic, scattered mica and carbonaceous specks, predominantly variably argillaceous, moderately indurated trace I-46 145 155 10 Dunvegan L_Dvgn L_Dvgn Sltst-VF-M_Ss dolomitic cement, tight, no shows. SANDSTONE: as previously described becoming increasingly consolidated in minor part with locally abundant tight calcareous cement and minor spotty kaolin, infer porosity as above with minor tight to poor I-46 155 162.5 7.5 Dunvegan L_Dvgn L_Dvgn VF-M_Ss streaks, no shows. SILTSTONE: light grey, minor medium grey, quartzose, minor to locally common biotite, trace to minor carbonaceous specks, rare glauconite, commonly clean to locally variably argillaceous, moderately to poorly indurate~, siliceous cement in part, trace to minor carbonaceous parting, locally variably sandy grading to minor very fine sandstone laminations to stringers, tight to poor porosity, no shows, minor medium grey very silty shale stringers and laminations, trace to minor medium brown dense I-46 162.5 172 9.5 Sully U_Sully U_Sully Sltst hard siderite nodules &lor stringers. SILTSTONE: similar to above, light to medium grey, quartzose, minor to locally common biotite, trace to minor carbonaceous specks, rare glauconite, commonly variably argillaceous to locally clean, moderately to poorly indurated, siliceous cement in part, trace carbonaceous parting, locally variably sandy grading to minor very fine sandstone laminations to stringers, tight, no shows, minor medium grey very silty shale stringers and laminations, trace brown sandy sideritic I-46 172 182 10 Sully U_Sully U_Sully Sltst laminations to stringers. SHALE with interbedded SILTSTONE: SHALE: medium to dark grey, brown grey, finn, sub blocky to sub platy, micromicaceous, predominantly very silty grading to argillaceous siltstone in part, I-46 182 190 8 Sully U_Sully U_Sully Shale-Sltst trace carbonaceous specks, SILTSTONE: as above. SANDSTONE with interbedded SILTSTONE and SHALE: SANDSTONE: disaggregated, very fine to medium grained, minor coarse to very coarse grains and pebble fragments, litharenite grading to sublitharenite, abundant white to frosted quartz with common varicolored lithic grains, rare to trace glauconit~) moderately to moderately poorly sorted, angular to subrounded to occasionally rounded, trace consolidated cuttings with abundant tight calcareous cement, infer tight to poor porGs~ty in part, poor to fair porosity in part, no shows; I-46 190 197 7 Sully U_Sully U_Sully Shale-VF-M_Ss SILTSTONE and SHALE: as above.

140 SHALE: dark grey, finn to locally hard, brittle in part, sub platy, fissile, predominantly smooth, locally slightly silty in minor part, trace framboidal pyrite micro-nodules, rare dark brown slightly dolomitic claystone I-46 197 202.6 5.6 Sully U_Sully U_Sully Shale laminations to stringers.

SANDSTONE: salt and pepper, fine to very coarse grained, gritty to slightly pebbly Iitharenite, abundant clear to frosted quartz with abundant predominantly dark grey to black chert grains, poorly sorted, angular to rounded, minor consolidated cuttings with common spotty to patchy calcareous cement, minor quartz.

some interbeds (~0.5 avg - range from 0.1-2.5cm), possibly abandoned channel, some bank collapse structures present, NWT01 42.1 43.85 1.75 Dunvegan L_Dvgn L_Dvgn Sltst-F_Ss heterolithic, ripples, some casts, planar and cross stratified beds pebble cgl, ripups from below, some heterolithic layers (shale w NWT01 43.85 44.6 0.75 Dunvegan L_Dvgn L_Dvgn Cgl ripups interbedded) rooted claystone or immature paleosol, some coaly fragments, NWT01 44.7 45.4 0.7 Dunvegan L_Dvgn L_Dvgn Shale root casts, slickensides some pyrite grains and coaly fragments near top with root casts extending downwards, some ripple and cross stratification NWT01 45.4 47 1.6 Dunvegan L_Dvgn L_Dvgn F_Ss preserved, crevasse splay deposits sh-sltst, ball and pillow structures, soft sediment deformation NWT01 47 47.9 0.9 Dunvegan L_Dvgn L_Dvgn Shale-Sltst features, some preserved ripple and x-strat overall fining upward sequence w cross strat preserved, some clasts in basal layer of beds, some heterolithic shale and sltst NWT01 47.9 50 2.1 Dunvegan L_Dvgn L_Dvgn F-M_Ss interbeds A-060-B/094-O-11 181.1 182.1 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith A-060-B/094-O-11 391.2 392.2 1 Sully U_Sully U_Sully Mdst assumed lith C-100-B/094-O-11 237.9 238.9 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith C-100-B/094-O-11 445.2 446.2 1 Sully U_Sully U_Sully Mdst assumed lith C-001-C/094-O-11 154.7 155.7 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith C-001-C/094-O-11 375.5 376.5 1 Sully U_Sully U_Sully Mdst assumed lith B-006-C/094-O-11 157.8 158.8 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith B-006-C/094-O-11 374 375 1 Sully U_Sully U_Sully Mdst assumed lith B-088-C/094-O-11 296.4 297.4 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith B-088-C/094-O-11 505.3 506.3 1 Sully U_Sully U_Sully Mdst assumed lith C-020-F/094-O-11 383.6 384.6 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith C-020-F/094-O-11 592.1 593.1 1 Sully U_Sully U_Sully Mdst assumed lith A-018-G/094-O-11 233.8 234.8 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith A-018-G/094-O-11 437.9 438.9 1 Sully U_Sully U_Sully Mdst assumed lith A-030-G/094-O-11 278 279 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith A-030-G/094-O-11 487.3 488.3 1 Sully U_Sully U_Sully Mdst assumed lith B-073-G/094-O-11 218.2 219.2 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith B-073-G/094-O-11 416.6 417.6 1 Sully U_Sully U_Sully Mdst assumed lith

141 B-079-G/094-O-11 331.7 332.7 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith B-079-G/094-O-11 534.2 535.2 1 Sully U_Sully U_Sully Mdst assumed lith A-096-G/094-O-11 314.9 315.9 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith A-096-G/094-O-11 507.2 508.2 1 Sully U_Sully U_Sully Mdst assumed lith C-003-J/094-O-11 235.8 236.8 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith C-003-J/094-O-11 424.6 425.6 1 Sully U_Sully U_Sully Mdst assumed lith B-039-J/094-O-11 332.1 333.1 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith B-039-J/094-O-11 523.1 524.1 1 Sully U_Sully U_Sully Mdst assumed lith D-045-J/094-O-11 263.9 264.9 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith D-045-J/094-O-11 460.7 461.7 1 Sully U_Sully U_Sully Mdst assumed lith D-076-J/094-O-11 267.8 268.8 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith D-076-J/094-O-11 469.4 470.4 1 Sully U_Sully U_Sully Mdst assumed lith B-004-K/094-O-11 403.2 404.2 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith B-004-K/094-O-11 595.3 596.3 1 Sully U_Sully U_Sully Mdst assumed lith A-059-L/094-O-11 403.4 404.4 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith A-059-L/094-O-11 615.6 616.6 1 Sully U_Sully U_Sully Mdst assumed lith C-030-A/094-O-12 272 273 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith C-030-A/094-O-12 422.1 423.1 1 Sully U_Sully U_Sully Mdst assumed lith A-091-A/094-O-12 346.3 347.3 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith A-091-A/094-O-12 537.6 538.6 1 Sully U_Sully U_Sully Mdst assumed lith A-096-G/094-O-13 754.7 755.7 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith A-096-G/094-O-13 954.1 955.1 1 Sully U_Sully U_Sully Mdst assumed lith C-060-E/094-O-14 608.3 609.3 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith C-060-E/094-O-14 807.6 808.6 1 Sully U_Sully U_Sully Mdst assumed lith D-070-J/094-O-14 147.1 148.1 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith D-070-J/094-O-14 350 351 1 Sully U_Sully U_Sully Mdst assumed lith C-069-K/094-O-14 325.8 326.8 1 Dunvegan U_Dvgn U_Dvgn Cgl assumed lith C-069-K/094-O-14 525.2 526.2 1 Sully U_Sully U_Sully Mdst assumed lith

142 Appendix G: Stratigraphic Logs Created Based on text descriptions provided in Appendix F, numerous stratigraphic logs were created to visually depict the text descriptions and allow for more detailed analyses and comparison. The logs, along with two well logs utilized, are found below in a roughly North to South order. The legend for lithology and symbology is below. At the end of Appendix G, iterations of stratigraphic correlations completed are shown to illustrate the connection between these stratigraphic logs and the stratigraphic cross sections presented in the main document.

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After the stratigraphic log creation, all logs were arranged from north to south and aligned with the Sully Formation used as a datum. This allowed for initial correlations between major lithologic units to be made and formed the basis for the delineation of an upper and lower Dunvegan Formation.

162

Afterwards, the logs were arranged spatially to better approximate their real location within the basin. This aided in correlating the different lithologic units across the Liard Basin from North to South. This broad correlation became the basis for the lithostratigraphic model presented within this study and shown in Figure 8b of the main text.

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Once the lithostratigraphic model had been created and additional data (both historic and newly collected) had been analysed and interpreted, an interpretation that the upper and lower Dunvegan Formation were fluvial-deltaic in nature emerged, which led to the categorization of lithologies based on their depositional character, across the basin. The correlation shown here is over-correlated, illustrating large scale channel and floodplain features that are continuous and extend the length of the basin, which is unlikely to be the case in reality.

164

From the previous figure, these large scale features were broken down based on more localized correlations between well logs and interpolation within areas lacking well density. This correlation resulted in an abundance of channel belts tied to specific well logs and associated based on lithologic characteristics defined in outcrop and well logs. The lower Dunvegan Formation (shown dominantly in yellow), was initially broken into channel belts, but upon further consideration, was further refined to include deltaic structures with some distributary channels (seen in the next cross section). The blank area not covered by channels in this cross section would be represented by either floodplain deposits or marine deposits.

165

channels

Finally, the sequence stratigraphic cross section was created that outlined the depositional characteristics of the upper and lower Dunvegan Formation based on the summation of collected data and associated interpretations. Combining datasets allowed for the confirmation that the upper Dunvegan Formation was dominated by fluvial deposits and the lower Dunvegan Formation was largely deltaic in nature with distributary channels present. Floodplain deposits encase the upper Dunvegan Formation channels and marine shales confine the lower Dunvegan Formation clinoforms and distributary channels. These correlations are based on a series of outcrop descriptions, well logs and newly collected core. The aim is to continue to improve these correlations through additional field work and outcrop descriptions, with the goal of further identifying fluvial morphology, deltaic nature and calibrating these features to hydrogeologic parameters. This section is the precursor to Figure 8c in the main text and follows the same trend shown in Figure 2b of the main text.

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Appendix H: Data Tables from Stratigraphic logs Based on the stratigraphic logs created, several data tables could be created to better analyse the Dunvegan Formation across these different datasets. Tables have been created that detail the thickness of the Dunvegan Formation and its respective units, as well as the breakdown of Conglomerate and Sandstone vs. Siltstone and Shale.

List of Tables Table H1: Dunvegan Formation Thicknesses ...... 168 Table H2: Dunvegan Formation Sandstone to Shale Ratio ...... 169 Table H3: Dunvegan Formation Sandstone to Shale Ratio for Lithostratigraphic Framework . 170 Table H4: Dunvegan Formation Sandstone to Shale Ratio for Sequence Stratigraphic Framework ...... 171 Table H5: Dunvegan Formation Conglomerate to Sandstone Ratio for Lithostratigraphic Framework ...... 172 Table H6: Dunvegan Formation Conglomerate to Sandstone Ratio for Sequence Stratigraphic Framework ...... 173

167

Table H1: Dunvegan Formation Thicknesses

Full DVGN 3 Package DVGN 2 Package DVGN ID Total U_DVGN M_DVGN L_DVGN U_DVGN L_DVGN Thickness Thickness Thickness Thickness Thickness Thickness NWT01 92.8 32.9 59.9 32.9 59.9 I-46 146.5 54.5 9.5 82.5 54.5 92 A-026 216.4 176.8 18.3 21.3 176.8 39.6 A-077 204.3 164.6 12.2 27.5 164.6 39.7 C-066 170 130.5 15 24.5 130.5 39.5 B-055 201.2 131.1 21.3 48.8 131.1 70.1 65-18 159.7 99.7 11 49 99.7 60 65-17 158.9 102.1 13.7 43.1 102.1 56.8 65-14 114.8 61.8 8.8 44.2 61.8 53 65-10A 186.2 109.7 38.1 73.5 109.7 73.5 65-10B 46.6 46.6 65-6 173.6 118.5 36.6 18.5 118.5 55.1 65-4 169.7 120.4 27.3 22 120.4 49.3 64-5 117 81.7 25.9 9.4 81.7 35.3 64-4 134.1 100.8 22.9 10.4 100.8 33.3 64-2 171.5 111.8 38.1 21.6 111.8 59.7 AVG 154.0 106.5 21.3 37.7 111.7 54.1

Table delineating the total thickness of the Dunvegan Formation across all logs; the thickness of the upper, middle and lower Dunvegan Formation units from the lithostratigraphic framework developed in this study, and; the thickness of the upper and lower Dunvegan Formation units from the sequence stratigraphic framework developed in this study. The average values are shown along the bottom. NWT01 data is a combination of core and ERT data.

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Table H2: Dunvegan Formation Sandstone to Shale Ratio

Full DVGN ID Total Ss Total Sh Total Ss&Sh Total %Ss Total %Sh NWT01 82.02 10.78 92.80 0.88 0.12 I-46 127.50 19.00 146.50 0.87 0.13 A-026 166.20 50.20 216.40 0.77 0.23 A-077 144.90 59.40 204.30 0.71 0.29 C-066 117.50 52.50 170.00 0.69 0.31 B-055 143.30 57.90 201.20 0.71 0.29 65-18 104.50 55.20 159.70 0.65 0.35 65-17 105.20 53.70 158.90 0.66 0.34 65-14 79.20 35.60 114.80 0.69 0.31 65-10A 167.70 53.60 221.30 0.76 0.24 65-10B 32.70 13.90 46.60 0.70 0.30 65-6 97.20 76.40 173.60 0.56 0.44 65-4 102.30 67.40 169.70 0.60 0.40 64-5 66.70 50.30 117.00 0.57 0.43 64-4 102.30 31.80 134.10 0.76 0.24 64-2 126.10 45.40 171.50 0.74 0.26 AVG 110.33 45.82 156.15 0.71 0.29

Table delineating the ratio of conglomerate and sandstone (termed Total Ss) to siltstone and shale (Termed Total Sh). The first and second columns show the total thickness (in m) of each, with the third column showing the total of Ss and Sh. The fourth and fifth columns break out the respective percentages based on the relative thicknesses. Average values are shown along the bottom. NWT01 data is a combination of core and ERT data.

169

Table H3: Dunvegan Formation Sandstone to Shale Ratio for Lithostratigraphic Framework

3 Package DVGN ID U_DVGN U_DVGN U_DVGN U_DVGN M_DVGN M_DVGN M_DVGN L_DVGN L_DVGN L_DVGN L_DVGN Ss Sh U_DVGN Ss&Sh %Ss %Sh Ss Sh M_DVGN Ss&Sh M_DVGN % Ss %Sh Ss Sh L_DVGN Ss&Sh %Ss %Sh NWT01 32.90 32.90 1.00 0.00 49.12 10.78 59.90 0.82 0.18 I-46 54.50 54.50 1.00 0.00 9.50 9.50 0.00 1.00 73.00 9.50 82.50 0.88 0.12 A-026 135.70 41.10 176.80 0.77 0.23 12.20 6.10 18.30 0.67 0.33 18.30 3.00 21.30 0.86 0.14 A-077 118.90 45.70 164.60 0.72 0.28 12.20 12.20 0.00 1.00 26.00 1.50 27.50 0.95 0.05 C-066 96.50 34.00 130.50 0.74 0.26 1.50 13.50 15.00 0.10 0.90 19.50 5.00 24.50 0.80 0.20 B-055 94.50 36.60 131.10 0.72 0.28 21.30 21.30 0.00 1.00 48.80 48.80 1.00 0.00 65-18 89.00 10.70 99.70 0.89 0.11 11.00 11.00 0.00 1.00 15.50 33.50 49.00 0.32 0.68 65-17 73.10 29.00 102.10 0.72 0.28 13.70 13.70 0.00 1.00 32.10 11.00 43.10 0.74 0.26 65-14 52.10 9.70 61.80 0.84 0.16 1.20 7.60 8.80 0.14 0.86 25.90 18.30 44.20 0.59 0.41 65-10A 109.70 109.70 1.00 0.00 38.10 38.10 0.00 1.00 58.00 15.50 73.50 0.79 0.21 65-10B 32.70 13.90 46.60 0.70 0.30 65-6 78.70 39.80 118.50 0.66 0.34 36.60 36.60 0.00 1.00 18.50 18.50 1.00 0.00 65-4 86.70 33.70 120.40 0.72 0.28 27.30 27.30 0.00 1.00 15.60 6.40 22.00 0.71 0.29 64-5 57.30 24.40 81.70 0.70 0.30 25.90 25.90 0.00 1.00 9.40 9.40 1.00 0.00 64-4 91.90 8.90 100.80 0.91 0.09 22.90 22.90 0.00 1.00 10.40 10.40 1.00 0.00 64-2 104.50 7.30 111.80 0.93 0.07 38.10 38.10 0.00 1.00 21.60 21.60 1.00 0.00 AVG 85.07 26.74 106.46 0.82 0.18 4.97 20.27 21.34 0.06 0.94 29.65 11.67 37.68 0.82 0.18

Table delineating the conglomerate and sandstone to siltstone and shale ratio for the 3 package Dunvegan Formation (upper Dunvegan, middle Shale Layer and lower Dunvegan) as outlined in the lithostratigraphic framework presented in this study. Blue represents the upper Dunvegan, orange represents the middle Shale Layer and yellow represents the lower Dunvegan. Similar to the previous table, within each zone, the first and second columns represent the thickness of the Ss and Sh portion in m, the middle column shows the total thickness in m and the fourth and fifth columns denote the relative percentages based on this. Averages are shown along the bottom. NWT01 data is a combination of core and ERT data.

170

Table H4: Dunvegan Formation Sandstone to Shale Ratio for Sequence Stratigraphic Framework

2 Package DVGN ID U_DVGN U_DVGN U_DVGN U_DVGN U_DVGN Ss Sh Ss&Sh %Ss %Sh ML_DVGN_Ss ML_DVGN_Sh ML_DVGN_Ss&Sh ML_DVGN_%Ss ML_DVGN_%Sh NWT01 32.90 32.90 1.00 0.00 49.12 10.78 59.90 0.82 0.18 I-46 54.50 54.50 1.00 0.00 73.00 19.00 92.00 0.79 0.21 A-026 135.70 41.10 176.80 0.77 0.23 30.50 9.10 39.60 0.77 0.23 A-077 118.90 45.70 164.60 0.72 0.28 26.00 13.70 39.70 0.65 0.35 C-066 96.50 34.00 130.50 0.74 0.26 21.00 18.50 39.50 0.53 0.47 B-055 94.50 36.60 131.10 0.72 0.28 48.80 21.30 70.10 0.70 0.30 65-18 89.00 10.70 99.70 0.89 0.11 15.50 44.50 60.00 0.26 0.74 65-17 73.10 29.00 102.10 0.72 0.28 32.10 24.70 56.80 0.57 0.43 65-14 52.10 9.70 61.80 0.84 0.16 27.10 25.90 53.00 0.51 0.49 65-10A 109.70 109.70 1.00 0.00 58.00 53.60 111.60 0.52 0.48 65-10B 32.70 13.90 46.60 0.70 0.30 65-6 78.70 39.80 118.50 0.66 0.34 18.50 36.60 55.10 0.34 0.66 65-4 86.70 33.70 120.40 0.72 0.28 15.60 33.70 49.30 0.32 0.68 64-5 57.30 24.40 81.70 0.70 0.30 9.40 25.90 35.30 0.27 0.73 64-4 91.90 8.90 100.80 0.91 0.09 10.40 22.90 33.30 0.31 0.69 64-2 104.50 7.30 111.80 0.93 0.07 21.60 38.10 59.70 0.36 0.64 AVG 85.07 26.74 106.46 0.82 0.18 30.58 25.76 56.34 0.53 0.47

Table delineating the conglomerate and sandstone to siltstone and shale ratio for the 2 package Dunvegan Formation (upper Dunvegan and lower Dunvegan) as outlined in the sequence stratigraphic framework presented in this study. Blue represents the upper Dunvegan and yellow represents the lower Dunvegan (which combines the middle Shale Layer and lower Dunvegan from the table above). Similar to the previous table, within each zone, the first and second columns represent the thickness of the Ss and Sh portion in m, the middle column shows the total thickness in m and the fourth and fifth columns denote the relative percentages based on this. Averages are shown along the bottom. NWT01 data is a combination of core and ERT data.

171

Table H5: Dunvegan Formation Conglomerate to Sandstone Ratio for Lithostratigraphic Framework

3 Package DVGN ID U_DVGN U_DVGN U_DVGN U_DVGN U_DVGN M_DVGN M_DVGN M_DVGN M_DVGN % M_DVGN L_DVGN L_DVGN L_DVGN L_DVGN L_DVGN Ss Cgl Ss&Cgl %Ss %Cgl Ss Cgl Ss&Cgl Ss %Cgl Ss Cgl Ss&Cgl %Ss %Cgl NWT01 1.10 4.00 5.10 0.22 0.78 0.00 0.00 0.00 0.00 0.00 4.50 0.80 5.30 0.85 0.15 I-46 45.50 9.00 54.50 0.83 0.17 0.00 0.00 0.00 0.00 0.00 73.00 0.00 73.00 1.00 0.00 A-026 10.70 125.00 135.70 0.08 0.92 12.20 0.00 12.20 1.00 0.00 15.20 3.10 18.30 0.83 0.17 A-077 12.20 93.00 105.20 0.12 0.88 0.00 0.00 0.00 0.00 0.00 13.80 12.20 26.00 0.53 0.47 C-066 7.00 89.50 96.50 0.07 0.93 1.50 0.00 1.50 1.00 0.00 16.50 3.00 19.50 0.85 0.15 B-055 0.00 94.50 94.50 0.00 1.00 0.00 0.00 0.00 0.00 0.00 0.00 48.87 48.87 0.00 1.00 65-18 18.30 70.70 89.00 0.21 0.79 0.00 0.00 0.00 0.00 0.00 15.50 0.00 15.50 1.00 0.00 65-17 7.60 65.50 73.10 0.10 0.90 0.00 0.00 0.00 0.00 0.00 32.10 0.00 32.10 1.00 0.00 65-14 24.70 27.40 52.10 0.47 0.53 1.20 0.00 1.20 1.00 0.00 18.30 7.60 25.90 0.71 0.29 65-10A 0.00 109.70 109.70 0.00 1.00 0.00 0.00 0.00 0.00 0.00 58.00 0.00 58.00 1.00 0.00 65-10B 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 32.70 0.00 32.70 1.00 0.00 65-6 9.10 69.60 78.70 0.12 0.88 0.00 0.00 0.00 0.00 0.00 16.40 2.10 18.50 0.89 0.11 65-4 9.70 77.00 86.70 0.11 0.89 0.00 0.00 0.00 0.00 0.00 15.60 0.00 15.60 1.00 0.00 64-5 5.80 51.50 57.30 0.10 0.90 0.00 0.00 0.00 0.00 0.00 9.40 0.00 9.40 1.00 0.00 64-4 7.00 84.90 91.90 0.08 0.92 0.00 0.00 0.00 0.00 0.00 10.40 0.00 10.40 1.00 0.00 64-2 8.50 96.00 104.50 0.08 0.92 0.00 0.00 0.00 0.00 0.00 21.60 0.00 21.60 1.00 0.00 AVG 11.15 71.15 77.16 0.17 0.83 1.06 0.00 0.93 0.21 0.00 22.06 4.85 26.92 0.85 0.15

Table delineating the conglomerate and sandstone ratio for the 3 package Dunvegan Formation (upper Dunvegan, middle Shale Layer and lower Dunvegan) as outlined in the lithostratigraphic framework presented in this study. In the previous tables, the conglomerate and sandstone ratio have been combined to come up with a Total Ss or %Ss value. In this table, the conglomerate and sandstone portion are split out to represent the variability in conglomerate to sandstone abundance based on the individual log and between the various units. Blue represents the upper Dunvegan, orange represents the middle Shale Layer and yellow represents the lower Dunvegan. Similar to the previous table, within each zone, the first and second columns represent the thickness of the Ss and Cgl portion in m, the middle column shows the total thickness in m and the fourth and fifth columns denote the relative percentages based on this. Averages are shown along the bottom. Whereas previous tables represented NWT01 as a combination of core and ERT data, here only core data is used as the ERT data could not differentiate between conglomerate and sandstone deposits definitively. NWT01 data is a combination of core and ERT data.

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Table H6: Dunvegan Formation Conglomerate to Sandstone Ratio for Sequence Stratigraphic Framework

2 Package DVGN ID U_DVGN U_DVGN U_DVGN U_DVGN U_DVGN Ss Sh Ss&Sh %Ss %Sh ML_DVGN_Ss ML_DVGN_Cgl ML_DVGN_Ss&Cgl ML_DVGN_%Ss ML_DVGN_%Cgl NWT01 1.10 4.00 5.10 0.22 0.78 4.50 0.80 5.30 0.85 0.15 I-46 45.50 9.00 54.50 0.83 0.17 73.00 0.00 73.00 1.00 0.00 A-026 10.70 125.00 135.70 0.08 0.92 27.40 3.10 30.50 0.90 0.10 A-077 12.20 93.00 105.20 0.12 0.88 13.80 12.20 26.00 0.53 0.47 C-066 7.00 89.50 96.50 0.07 0.93 18.00 3.00 21.00 0.86 0.14 B-055 0.00 94.50 94.50 0.00 1.00 0.00 48.87 48.87 0.00 1.00 65-18 18.30 70.70 89.00 0.21 0.79 15.50 0.00 15.50 1.00 0.00 65-17 7.60 65.50 73.10 0.10 0.90 32.10 0.00 32.10 1.00 0.00 65-14 24.70 27.40 52.10 0.47 0.53 19.50 7.60 27.10 0.72 0.28 65-10A 0.00 109.70 109.70 0.00 1.00 58.00 0.00 58.00 1.00 0.00 65-10B 0.00 32.70 0.00 32.70 1.00 0.00 65-6 9.10 69.60 78.70 0.12 0.88 16.40 2.10 18.50 0.89 0.11 65-4 9.70 77.00 86.70 0.11 0.89 15.60 0.00 15.60 1.00 0.00 64-5 5.80 51.50 57.30 0.10 0.90 9.40 0.00 9.40 1.00 0.00 64-4 7.00 84.90 91.90 0.08 0.92 10.40 0.00 10.40 1.00 0.00 64-2 8.50 96.00 104.50 0.08 0.92 21.60 0.00 21.60 1.00 0.00 AVG 11.15 71.15 77.16 0.17 0.83 22.99 4.85 27.85 0.86 0.14

Table delineating the conglomerate and sandstone to siltstone and shale ratio for the 2 package Dunvegan Formation (upper Dunvegan and lower Dunvegan) as outlined in the sequence stratigraphic framework presented in this study. In the previous tables, the conglomerate and sandstone ratio have been combined to come up with a Total Ss or %Ss value. In this table, the conglomerate and sandstone portion are split out to represent the variability in conglomerate to sandstone abundance based on the individual log and between the various units. Blue represents the upper Dunvegan and yellow represents the lower Dunvegan (which combines the middle Shale Layer and lower Dunvegan from the table above). Similar to the previous table, within each zone, the first and second columns represent the thickness of the Ss and Cgl portion in m, the middle column shows the total thickness in m and the fourth and fifth columns denote the relative percentages based on this. Averages are shown along the bottom. Whereas previous tables represented NWT01 as a combination of core and ERT data, here only core data is used as the ERT data could not differentiate between conglomerate and sandstone deposits definitively.

173

Appendix I: Complete ERT Results

Table of Contents List of Tables ...... 174 List of Figures ...... 174 Interpretation of Resistivity Measurements ...... 177 Measured and Calculated Apparent Resistivity Pseudosections with Processed Data ...... 179

List of Tables Table I1: Resistivities of Common Geological Materials (modified from Reynolds, 2011)...... 177

List of Figures

Figure I1: 2D Electrical Resistivity Pseudo-Section (from Samouelian et al., 2005)...... 176 Figure I2: Waste Facility (R1) Wenner-Schlumberger section……………………………………………………….……..181 Figure I3: Waste Facility (R1) dipole-dipole section……………………………………………………….……………….……182 Figure I4: Northwestel Site (R2) Wenner-Schlumberger section…………………………………..……………….…….183 Figure I5: Northwestel Site (R2) dipole-dipole section ………………………………………………………………….…….184 Figure I6: Columbia Gas Plant (R3) dipole-dipole section…………………………………………….………………..….…185 Figure I7: Nine Mile (R4) Wenner-Schlumberger site………………………………………………….…………….…………186 Figure I8: Nine Mile (R4) dipole-dipole section………………………………………………………….………………….…….187 Figure I9: Weigh Scale (R5) Wenner-Schlumberger section……………………………………….………………….…….188 Figure I10: Weigh Scale (R5) dipole-dipole section …………………………………………………….………………….……189 Figure I11: Weigh Scale (R5) Wenner-Schlumber and dipole-dipole section with revised contours……..190 Figure I12: Weigh Scale (R5) Wenner-Schlumber section with revised contours……………………………….…191 Figure I13: Weigh Scale (R5) dipole-dipole section with revised contours……………………………………………192

174

Electrical resistivity tomography (ERT) refers to the collinear collection of resistivity data, which is presented as a two-dimensional resistivity pseudo-section, i.e., a two-dimensional vertical section of the medium along the survey line. To achieve this, the current and potential electrodes are maintained at a regular fixed distance from each other and are progressively moved along a line at the soil surface to construct a profile of resistivity values (Figure I1). The inter-electrode spacing is then increased by some factor (i.e., n = 2), and the measurements are repeated; the increase in electrode spacing (n factor) increases the volume of soil (i.e., depth of investigation) influencing the flow of injected current. This process is repeated until the maximum spacing between electrodes in reached. Measurements can be repeated at a single location to improve the signal-to-noise ratio. The efficient acquisition of such data is achieved using multi-channel resistivity systems, which automatically switches the electrode pairs over a series of interconnected electrodes.

Wenner-Schlumberger and dipole-dipole arrays were utilized in this study. These arrays utilize different electrode pairings and spacings to image the subsurface. The Wenner-

Schlumberger array is set up to provide more balanced sensitivity to vertical and horizontal structures and has a higher signal-to-noise ratio than the dipole-dipole array, which has less vertical resolution but provides good horizontal resolution, with the ability to detect small-scale structures such as cavities in the subsurface (Loke, 2004). Each survey method has benefits and in this study both were datasets were collected to gain an understanding of the vertical and horizontal variability in the subsurface such that model outputs could be compared.

175

Figure I1: 2D Electrical Resistivity Pseudo-Section (from Samouelian et al., 2005).

176

Interpretation of Resistivity Measurements The quality of a resistivity measurement is largely dependent on the electrode contact resistance with the soil. Because resistivity methods inject current directly into the ground, their electrodes need to be in good contact (i.e., low contact resistance) with the material they are implanted in. High contact resistances result in low applied currents, and hence, weak potential difference measurements. High contact resistances are particularly common when the surface material consists of dry sand, gravel, boulders, or frozen ground. This problem can be partially overcome by wetting the material around the inserted electrodes or increasing the surface area of the electrode in contact with the soil (i.e., using larger or multiple electrodes).

Table I1: Resistivities of Common Geological Materials (modified from Reynolds, 2011).

Material Nominal Resistivity Material Nominal Resistivity Rock ( m) Unconsolidated ( m)

Quartz 300 – 106 Clay 1 – 1000

6 Granite 300 – 1.3  10 Alluvium and sand 10 – 800 Granite (weathered) 30 – 500 Moraine 10 – 5  103

Basalt 10 – 1.3  107 Soil (40% clay) 8

Sandstone 1 – 7.4  108 Soil (20% clay) 33 Limestone 50 – 107 Topsoil 250 – 1700

Dolomite 350 – 5  103 Clay (dry) 50 – 150

Slate 600 – 4  107 Gravel (dry) 1400 Shale 20 – 2000 Gravel (saturated) 100 Quaternary Sand 50 – 100 Dry Sandy Soil 80 – 1050 Sand and Gravel 30 – 225

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The presence of localized geologic units within a relatively uniform halfspace, which are insignificant in relation to the main geologic target, can degrade the quality of field data and ultimately reduce the effectiveness of the interpretation. For example, a clay lens located at some orthogonal distance from a collinear array could distort the current flow lines and equipotentials toward the conductive anomaly. This would result in spatially variable potential measurements, which would not only vary with position but also the geometry of the electrode configuration. This is an inherent limitation in the interpretation of 2D measurements in a 3D environment. While a buried bedrock valley is not an isolated body, its linear anisotropic nature with respect to the surrounding media may also affect the uniformity of the current flow lines around the array, particularly if the array is not orthogonal to the valley strike. Therefore, the interpretation of collinear resistivity data collected non-orthogonally over a valley may be subject to higher uncertainty, particularly along the valley walls where the potential distortion would be greatest.

The interpretation of resistivity data is further complicated by the fact that a geologic section may show a series of lithologically defined interfaces with similar electrical properties, i.e. note the potential overlap in resistivities for different materials in Table I1. Therefore, geologic interfaces may not coincide with electrical boundaries. For instance, an unconfined sandstone aquifer would be defined by two electrically different units at the capillary fringe, even though the geologic unit has not changed. Because the resistivity  of a unit is dependent on the surface area and length, as well as the resistance of the material, it is not possible to know both the true layer resistivity and the layer thickness, which is a problem known as equivalence. In other words, there are many combinations of layer thickness and resistivity that would give the same geophysical response. If successive geologic layers exhibit similar electrical properties or one layer is

178 relatively thin, that unit may be indistinguishable from the adjacent units and become supressed in the apparent resistivity data.

Inverse methods are used to aid in the interpretation of apparent resistivity data. Typically, least-squares optimisation is used in which a starting model is adjusted successively until the difference between the observed and modeled pseudo-sections is reduced to a minimum (Barker,

1992). Finite-element forward modelling is used to assess the fit of each model pseudosection in an iterative manner, until the difference between successive RMS errors reaches an acceptable value. The best fit model to the observed apparent resistivity pseudo-section is considered the

‘true’ resistivity-depth model section underlying the array.

Measured and Calculated Apparent Resistivity Pseudosections with Processed Data

RES2DINV takes the measured apparent resistivity data collected in the field and attempts to match this data through calculating similar apparent resistivity values. The software does this process iteratively until it has reached a best approximation of the field data. From this, a processed section is created which is a 2D representation of the subsurface resistivities. The model output provides these files visually. These visual representations of the raw data are presented below. The top pseudosection represents the apparent resistivity data that was collected in the field. The middle pseudosection represents the calculated apparent resistivity data that is the best match to the measured data. From this calculated data, the bottom section which shows the inverse model resistivity section, is created. This output helps to show how closely the measured and calculated apparent resistivities match and helps to visually indicate potential errors in the dataset.

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Additionally, a second representation of the Weigh Scale resistivity sections (R5) have been presented. The sections presented within this appendix are shown with a log scale that was user defined. The Weigh Scale site had small resistivity variations, which caused a lack of variation to be seen within these sections. For this reason, computer defined linear contour sections were also created to illustrate some of the small-scale internal variations that exist. These sections are presented here to build on the sections plotted with log contour intervals that are presented within the thesis body (Figure 11 & Figure 12).

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Figure I2: Waste Facility (R1) Wenner-Schlumberger section

Cross sections created in RES2DINV from the Wenner-Schlumberger array data at the Municipal Waste Facility site, showing the measured apparent resistivity pseudosection (top) compared to the calculated apparent resistivity pseudosection (middle), with the produced inverse model resistivity section created from these calculated values shown at the bottom.

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Figure I3: Waste Facility (R1) dipole-dipole section

Cross sections created in RES2DINV from the Dipole-Dipole array data at the Municipal Waste Facility site, showing the measured apparent resistivity pseudosection (top) compared to the calculated apparent resistivity pseudosection (middle), with the produced inverse model resistivity section created from these calculated values shown at the bottom.

182

Figure I4: Northwestel Site (R2) Wenner-Schlumberger section

Cross sections created in RES2DINV from the Wenner-Schlumberger array data at the Northwestel Tower site, showing the measured apparent resistivity pseudosection (top) compared to the calculated apparent resistivity pseudosection (middle), with the produced inverse model resistivity section created from these calculated values shown at the bottom.

183

Figure I5: Northwestel Site (R2) dipole-dipole section

Cross sections created in RES2DINV from the Dipole-Dipole array data at the Northwestel Tower site, showing the measured apparent resistivity pseudosection (top) compared to the calculated apparent resistivity pseudosection (middle), with the produced inverse model resistivity section created from these calculated values shown at the bottom.

184

Figure I6: Columbia Gas Plant (R3) dipole-dipole section

Cross sections created in RES2DINV from the Dipole-Dipole array data at the Columbia Gas Plant site, showing the measured apparent resistivity pseudosection (top) compared to the calculated apparent resistivity pseudosection (middle), with the produced inverse model resistivity section created from these calculated values shown at the bottom.

185

Figure I7: Nine Mile (R4) Wenner-Schlumberger site

Cross sections created in RES2DINV from the Wenner-Schlumberger array data at the Nine Mile site, showing the measured apparent resistivity pseudosection (top) compared to the calculated apparent resistivity pseudosection (middle), with the produced inverse model resistivity section created from these calculated values shown at the bottom.

186

Figure I8: Nine Mile (R4) dipole-dipole section

Cross sections created in RES2DINV from the Dipole-Dipole array data at the Nine Mile site, showing the measured apparent resistivity pseudosection (top) compared to the calculated apparent resistivity pseudosection (middle), with the produced inverse model resistivity section created from these calculated values shown at the bottom.

187

Figure I9: Weigh Scale (R5) Wenner-Schlumberger section

Cross sections created in RES2DINV from the Wenner-Schlumberger array data at the Weigh Scale site, showing the measured apparent resistivity pseudosection (top) compared to the calculated apparent resistivity pseudosection (middle), with the produced inverse model resistivity section created from these calculated values shown at the bottom.

188

Figure I10: Weigh Scale (R5) dipole-dipole section

Cross sections created in RES2DINV from the Dipole-Dipole array data at the Weigh Scale site, showing the measured apparent resistivity pseudosection (top) compared to the calculated apparent resistivity pseudosection (middle), with the produced inverse model resistivity section created from these calculated values shown at the bottom.

189

Figure I11: Weigh Scale (R5) Wenner-Schlumber and dipole-dipole section with revised contours

Weigh Scale site sections showing A) the dipole-dipole array and B) the Wenner-Schlumberger array outputs, using a linear contour interval to better represent internal formation heterogeneity.

190

Figure I12: Weigh Scale (R5) Wenner-Schlumber section with revised contours

191

Figure I13: Weigh Scale (R5) dipole-dipole section with revised contours

192

Appendix J: 2022 Field Plan and Details

Table of Contents List of Figures ...... 193 Planned Future Field Work ...... 194 General Approach to 2020 Field Activities ...... 194 Drilling Methodology ...... 194 WestbayTM Multilevel System ...... 195 Fully Grouted Pressure Transducer Strings ...... 196 Distributed Temperature Sensing Fibre-Optic Cable ...... 196 Surface Completions ...... 197 Amendment to MVLWB Land Use Permit ...... 197 References ...... 198

List of Figures Figure J1: Schematic detailing paired borehole technique to be used during future field episodes ...... 199 Figure J2: Installation options for a Westbay MLS under different conditions ...... 200 Figure J3: Schematic (front view) showing transducer string and A-DTS cable installation ...... 201 Figure J4: Schematic (top view) showing transducer string and A-DTS cable installation ...... 202 Figure J5: Photo of Pedestal enclosure for storing transducer string telemetry equipment ...... 203 Figure J6: Photo collage of custom well boxes for future boreholes ...... 204

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Planned Future Field Work In preparation for the field episode planned for 2020, much work was completed. Though the field episode was postponed due to concerns related to the COVID-19 pandemic, this preparatory work will facilitate the field episode, once it is rescheduled, likely in March 2022. The below description and attached appendices outline the customized workplan that was created for this 2020 field work (Parker et al., 2020). General Approach to 2020 Field Activities The initial scope of work for the August 2019 field episode entailed drilling two boreholes and installing a Westbay multi-level system in one borehole, designed based off core and downhole geophysical and hydrophysical data collected. In the second borehole, a FLUTeTM liner with temporary sensor deployments was to be installed. The temporary deployments include an A-DTS fibre-optic cable and a custom string of pressure transducers (Figure J1). Information collected over time from these sensor deployments would help plan future permanent multi-level groundwater sampling systems in this and other boreholes. However, unstable conditions made this impossible for NWT01 in August 2019. Given the conditions encountered in 2019, an updated approach to field work in 2020, based on conversations with experienced drillers, included drilling two paired boreholes to depths of 100- 149 m at three locations; the Weigh Scale site (R5), the Municipal Waste Facility site (R1) and the Northwestel site (R2), using a combination of drilling techniques. Due to the high cost of drilling and unconfirmed funding, it was decided a stepped approach would occur, where drilling at one location would occur first while waiting to hear about additional funds. Planned drilling activities in March 2020 were to start at the Northwestel Tower Facility (R2) as it is located near to the Bovie Structure, where previous drilling activities have indicated the occurrence of hydrocarbon migration and pooling at depths as shallow as ~500 mbgs (Government of Yukon, 2001). It was proposed that drilling methods providing continuous rock core would be used for the first hole in which the WestbayTM multi-level system (MLS) would be installed. The second borehole at each site would be completed with a string of vibrating wire (VW) pressure transducers and a fibre-optic cable grouted in place. In order to limit the potential impact of grout on downgradient hydrochemistry the second hole was to be drilled downgradient of the first hole. Both the string of VW pressure transducers, consisting of approximately 30 transducers, and the WestbayTM system with approximately 30-40 ports, were ordered based on generic designs that covered the entire length of the hole with high-resolution sensors and sampling capabilities. The WestbayTM MLS could be adjusted in the field depending on encountered field conditions. An alternative drilling method, likely air rotary, was to be used at the second hole to improve drilling speed. Given the remote nature of the field site, it was determined a telemetry system would be required to collect continuous data from the VW pressure transducers and fibre-optic cable, such that real time data, including pressure and temperature data could be relayed to researchers at the University of Guelph to allow for continuous monitoring and analysis. Drilling Methodology In 2019, a standard approach to obtaining continuous core was implemented using a CCME 650 track-mounted drill rig equipped with a triple tube HQ3 wireline coring system. However, after difficulties using this approach, where unstable ground was encountered and resulted in the premature abandonment of two boreholes, it was determined an approach using multiple drilling methods was necessary. The experience from NWT01-A and NWT01 was summarized and shared

194 with several drilling companies while other approaches to the DFN-M approach (Parker et al., 2012) were being considered to retain the multiple lines of evidence useful for robust flow system interpretations. Based on discussions with three drilling companies, it was determined that the best method would include the use of a rotosonic drill rig equipped with the capability of using wireline coring and air rotary systems. Three companies based in Western Canada were contacted and based on these initial meetings a detailed Request for Proposal (RFP) was developed outlining the goals of the project and the drilling approach and requirements. In general, it was determined that the drilling company must have a rig with the capability of using rotosonic, HQ3 wireline coring and air rotary or air hammer systems. The HQ3 wireline coring system would be used to core the first hole if competent rock was encountered. The air rotary or air hammer drilling method was of interest for the second hole as it allows holes to be drilled quickly, without the collection of continuous core. The rotosonic drilling option was to act as backup for these two methods, to ensure that holes could be completed to depth regardless of encountered conditions. Omega Environmental and Geotechnical Drilling, a small drilling company with a focus on environmental and geotechnical work, was chosen as the drilling contractor. This decision was made because Omega had the most comprehensive rotosonic drill rig, capable of HQ3 wireline coring and air rotary drilling, with a rating down to depths of 175 m, with the potential to drill deeper under certain instances. Further, Omega had completed a similar baseline groundwater quality study in the Montney basin, with similar drilling and installations and, therefore, came highly recommended. WestbayTM Multilevel System A WestbayTM MLS is comprised of pieces of PVC with couplings. Some pieces have packers attached and some serve as ports where there are holes and/or screens in the casing to connect the system to groundwater in the formation. The WestbayTM system requires tools lowered down the inside of the casing to access the ports for measurement of water pressure and to collect groundwater samples (Cherry et al., 2015; Cherry et al., 2017). Generally, these systems are installed within boreholes that are 4 inches in diameter, and sampling intervals are sealed using inflatable packers. However, due to the unstable borehole conditions encountered in August 2019, designs for both back-filled and standard packer systems were considered for 2020. A WestbayTM system measuring 120 m in length, with 30 ports and 30 standard size packers was purchased for the August 2019 field episode and remains in storage in Fort Liard. Additional parts are currently on order with WestbayTM to augment this system so it can be installed regardless of encountered conditions. Discussions between WestbayTM personnel, the drilling team and G360 resulted in the need for additional parts, including a set of 10 extra monitoring ports, 10 extra normal sized packers, a set of 10 larger sized packers capable of sealing a 4.8-6.3-inch hole and backfill material. With these parts available three potential options under different scenarios are possible i) standard-sized packers, if encountered conditions include competent rock, ii) larger-size packers, if the larger-size drilling rods and casing are required to provide stability at shallower depths, and iii) backfill material consisting of sand and bentonite and basic WestbayTM pipe, if encountered conditions are unstable or if the hole diameter has to be increased to 7-8 inches near surface (Figure J2). Additional WestbayTM ports were also purchased so that the design could be updated in the field and the location of sampling ports shifted to cover the areas of interest. The current generic design for the WestbayTM system will monitor a hole to a depth of 149 m and include up to 40 sampling ports, which corresponds to a monitoring zone

195 every 3.725 m in the hole. Once installed, each port will be sampled for a complete suite of hydrochemistry, isotope and hydrocarbon analyses. Fully Grouted Pressure Transducer Strings The unstable nature of the rock encountered in 2019 would not allow for the installation of a string of transducers behind a blank FLUTeTM liner, used to provide continuous hydraulic head and temperature data. An alternative approach includes permanently grouting-in-place a set of vibrating wire pressure transducers, providing the same continuous hydraulic head measurements, but at a reduced spatial resolution and requiring a dedicated borehole. Three companies were contacted that all had experience with these systems but had slightly variable configurations and capabilities when it came to design and transmitting the data remotely. Each company provided comparable quotes after discussion. After careful review of each quote, it was determined that RST Instruments was the best option. Further discussion with Omega Drilling revealed that RST is the industry standard. RST themselves stated that the system they have designed with us for this project is likely the highest resolution system they have ever produced, and they are excited and interested to see the results. The system built by RST can accommodate up to 12 pressure transducers per string, with one of these pressure transducers being able to read temperature. This system allowed for 36 pressure transducers to be installed down hole, using three strings. The three strings would be attached to a PVC tube, to ensure they did not become tangled down hole and so that the depths could be ensured to be accurate (Figure J3; Figure J4). Grout would then be injected down the centre of this tube so that the hole was filled with grout from the bottom of the hole upwards, ensuring good seals between the individual pressure transducers. The three strings would run to surface, where they would be attached to a datalogger and then connected to a telemetry system with a cell modem. This cell modem would turn on several times per day to relay data back to Guelph. Power for this system would be provided by a battery that would be charged using a solar panel. The equipment will be housed in a Pedestal enclosure, which is custom designed to collect and transmit all associated data. This enclosure is insulated and protected, to ensure the safety of the equipment (Figure J5). Distributed Temperature Sensing Fibre-Optic Cable In conjunction with the VW pressure transducers, a dedicated fibre optic cable will be grouted into the second hole (Figure J3; Figure J4). Dr. Jonathan Munn of G360 is a DTS specialist and is taking the lead on using a telemetry system to collect and transmit real-time temperature data collected using the fibre optic cable. After completing some research and speaking with the equipment manufacturer, Silixa, it was determined that a similar setup to the RST system would be possible, whereby a cellular modem could be installed on site with a battery and solar panel backup to provide power. The DTS cable would be attached to the same PVC tube as the strings of pressure transducers, but instead of connecting to the RST datalogger, it would connect at surface to the DTS datalogger. This would allow for A-DTS profiles to be collected when G360 researchers are on site to facilitate heating the borehole, with an ambient DTS profile being collected at all other times. The DTS system would connect to a cellular modem that allows for remote access and data downloads. The equipment and design considerations have been advanced by G360 with Silixa as part of an on-going collaboration though Dr. Beth Parker’s NSERC Industrial Research Grant, led by G360 Researchers, Drs. Jonathan Mun and Carlos Maldaner.

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Surface Completions Appropriately sized well completions at ground surface are needed to accommodate the equipment needs at surface. Conventional surface completions for monitoring wells typically consist of 6-9- inch diameter metal cylinders, however, these do not provide adequate long-term storage for the telemetry equipment used for this project. Custom well boxes fabricated by WellMaster, 2 ft in length, 2 ft in width and 3 ft in height, will provide the secure storage capacity needed at the wellhead (Figure J6). The well boxes are constructed of aluminum, for both strength and light weight. The well boxes have a locking lid and will be bolted to a concrete apron surrounding the well, so that any water readily drains out of the bottom of the box. Insulation can be placed within the box to moderate the temperature. These well boxes will be used at all wells (both those with Westbay systems and permanent downhole installations). Amendment to MVLWB Land Use Permit The updated approach to the field work required adjustments to the current Mackenzie Valley Land and Water Board Land Use Permit. The permit was amended in consultation with the Government of the Northwest Territories, the First Nation’s in the region, and the Hamlet of Fort Liard. Changes were minor and included, altering the drilling methods, increasing the size and footprint of the drill rig, and increasing the amount of water to be used. The approved land use permit was received on March 13, 2020. This updated land use permit will still be active in March 2022 when the rescheduled field work is expected to commence.

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References Cherry, J. A., Parker, B. L., Einarson, M., Chapman, S. W., Meyer, J. R. 2015. Overview of depth- discrete multilevel groundwater monitoring technologies: Focus on groundwater monitoring in areas of oil and gas well stimulation in California, Appendix 11, in Esser et al., 2015, Recommendations on Model Criteria for Groundwater Sampling, Testing, and Monitoring of Oil and Gas Development in California, Lawrence Livermore National Laboratory, LLNL‐TR‐ 669645. Cherry, J. A., Parker, B. L., Chapman, S. W., Meyer, J. R., & Pierce, A. A. (2017). Depth Discrete Multilevel Monitoring in Fractured Rock : State of the Technology and Implications. GWD Conference 2017, 15th Biennial Ground Water Division Conference. Government of Yukon, Oil and Gas Resources Branch. 2001. Petroleum Resources Assessment of the Liard Plateau, Yukon Territory, Canada. National Energy Board for Energy Resources Branch, Whitehorse, Yukon, Open File: ISBN 1-55018-801-1. Parker, B. L., Cherry, J. A., & Chapman, S. W., 2012. Discrete fracture network approach for studying contamination in fractured rock. AQUA mundi, 3(2), 101-116. Parker, B. L., Steelman, C. M., Mayer, B., Darrah, T. & Mayer, K. U., 2020. Baseline Groundwater Monitoring in the Transboundary Liard Basin for Source Water Protection. NSERC Alliance Grant Proposal Submitted Jan. 31, 2020.

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Figure J1: Schematic detailing paired borehole technique to be used during future field episodes

Schematic showing proposed paired boreholes at each site. The borehole on the left shows the strings of pressure sensors (vibrating wire pressure transducers) and the fibre optic cable grouted in place and the right borehole shows a back-filled Westbay multi-level system, being one of the ways that the multi-level could be installed. The vertical profile to the right of each figure shows the datasets that can be collected.

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Figure J2: Installation options for a Westbay MLS under different conditions

Schematic showing three possible Westbay completion methods in one figure. These methods could entail utilizing smaller packers (lower portion of the sketch), larger packers (mid-portion of the sketch) and backfilling material (upper portion of the sketch). This figure shows versatility of completion with borehole diameters depending on drilling. All of these completion methods could not be used within the same borehole, but combinations based on specific well size and construction can be created.

200

Figure J3: Schematic (front view) showing transducer string and A-DTS cable installation

Schematic showing the front view of the installation procedure for the second of the paired boreholes, which would entail attaching pressure transducer strings and a DTS fibre optic cable to the outside of a PVC tube and grouting through the middle of the PVC tremie tube.

201

Figure J4: Schematic (top view) showing transducer string and A-DTS cable installation

Schematic showing the top view of the installation procedure for the second of the paired boreholes.

202

Figure J5: Photo of Pedestal enclosure for storing transducer string telemetry equipment

Image showing the RST pedestal enclosure with the insulated battery at the base and the datalogger stored above it.

203

Figure J6: Photo collage of custom well boxes for future boreholes

Photos of the G360 custom-made aluminum well boxes with dimensions of 2x2x3 feet (LxWxH) with locking lid and open bottom to allow for secure storage of equipment within.

204

Appendix K: A-DTS Results

Table of Contents List of Figures ...... 205 Active Distributed Temperature Sensing (A-DTS) ...... 206 A-DTS Results ...... 206 References ...... 208

List of Figures Figure K1: Photo collage detailing downhole A-DTS testing within NWT01 ...... 209 Figure K2: WellCAD montage detailing field data collected from NWT01 ...... 210

205

Active Distributed Temperature Sensing (A-DTS) An A-DTS test uses temperature to identify zones of active groundwater flow within a borehole. The fibre optic cable will allow continuous depth-discrete temperature monitoring along the full length of the borehole to identify natural variations in temperature, as well as periodic Active Distributed Temperature Sensing (A-DTS) tests. A-DTS tests are where the cable is heated at a constant rate along the full length of the cable. Temperature differences along the cable are measured and can be related to variations in groundwater flow (areas of preferential cooling indicate more active groundwater flow paths). The natural temperature variability can provide insight to seasonal changes and potentially groundwater recharge from precipitation events, and the A-DTS thermal testing can help identify and quantify the magnitude of hydraulically active flow pathways in the subsurface. Further information on DTS and A-DTS tools and techniques can be found in Coleman et al. (2015), Maldaner et al. (2019) and Munn et al. (2020). The Active Distributed Temperature Sensing (A-DTS) test was completed in borehole NWT01 on August 21-22, 2019 (Figure K1). A fibre-optic cable was lowered down the borehole, and the hole was subsequently filled with cement to surface, creating a permanent cable installation. The cable was weighted such that it hung straight and was placed along the edge of the borehole wall. The cement was left to cure overnight and upon returning the following morning it was found that the cement level had dropped to approximately 6 mbgs; additional cement was added to top off the hole to ground surface. The active, or heating, portion of the test started at 10:00 on August 21, 2019, and the temperature along the full length of the borehole was monitored continuously over a 24-hour heating period. The active portion of the test was shut off at 10:00 the following morning and the cooling response was measured for an additional 20-hours. A-DTS Results Temperature response data collected during the heating portion of the A-DTS test showed several cooling responses that may relate to intervals with active groundwater flow. From surface to approximately 2 to 3 mbgs a warmer (more yellow) section of the A-DTS profile was observed, which appears to correspond to the unsaturated or vadose zone above the water table. The vadose zone has a warm signature as the air in the pore spaces have a much lower thermal conductivity than the water filled pore spaces found in the saturated zone below the water table. Underlying the vadose zone to a depth of 14.8 mbgs, there is a slightly elevated temperature observed during heating, indicating a zone of relatively low groundwater flow. From approximately 14.8 to 16.6 mbgs there is a slightly cooler lens, likely indicating a zone of more active groundwater flow. Minimal variability in the heating profile was observed from 16.6 mbgs to approximately 37.2 mbgs, indicating no obvious groundwater flow zones. Below 37.2 mbgs a number of important temperature changes were observed. From 37.2 to 38.3 mbgs a much cooler section of the profile indicates an interval or feature with strong evidence of active flow. Five potential flow zones were marked by slightly cooler bands in the A-DTS profile at the following depths: 39.9, 41.15, 44.8, 48.2 and 49.3 mbgs. In some instances, it is possible to estimate thermal conductivity and volumetric flow rates from A-DTS tests (Maldaner et al., 2019). Comparing the in-situ apparent thermal conductivity from the A-DTS test to the measured or expected rock thermal conductivity provides a more quantitative

206 means of identifying zones of enhanced heat transfer, which would correspond to zones of active groundwater flow. Upon processing the A-DTS temperature data to calculate apparent thermal conductivity it was discovered that the heat generated from the curing cement significantly affected the thermal response test, particularly in the later portions of the test. The heat generated from the curing cement appeared to decrease approximately 8 hours into the A-DTS test, which resulted in the cable cooling slightly at all depths. This overprinting thermal signal made reliable calculation of apparent thermal conductivity not possible using the full 24 hours of heating data. As this overprinting thermal signal appeared to most strongly impact the later portion of the data, the apparent thermal conductivity for the first 8 hours is presented and provides some evidence of enhancement in the intervals described above (Figure K2). While the results demonstrate reasonable values of apparent thermal conductivity, the A-DTS test should be repeated at a later date when the heat from the curing cement has fully dissipated. In general, enhancements in the thermal conductivity (spikes) correspond to intervals with a cooler temperature during heating. Slight changes can also be caused by variations in mineralogy such as the decrease in thermal conductivity between 10.9-13.4 m that could correspond to a more clay-rich zone. The largest enhancements are located in the lower portion of the borehole and are located in the zones with strong cooling described previously. The largest enhancement is observed between 37.2-38.3 m where a portion shows a negative thermal conductivity. It is not possible to have a negative thermal conductivity and this interval suggests too much flow to allow enough heat to build up to estimate the thermal conductivity. A longer test, or a higher heat output would resolve this issue. Regardless, it is very strong evidence of a highly active flow feature or zone at this depth. Although the overprinting thermal signals confounded the quantitative results of the A-DTS test, it provides strong evidence of highly variable flow throughout the geological sequence. Subsequent testing at this location and in future boreholes will provide further evidence as to the lateral extent and variability of these active flow zones. A point of interest is that the most evident flow zone lies just above the contact between the upper and lower Dunvegan Formations, potentially indicating that there is an hydraulic barrier between these two units and that there is elevated groundwater flow just above this interval. Collecting hydraulic head profiles in time will help to better elucidate where these changes in hydraulic head are, helping to illuminate hydraulic barriers, or aquifer/aquitard boundaries. Overall, there is a lack of obvious enhancements, and thus groundwater flow zones, throughout the majority of the upper Dunvegan Formation, which is peculiar given the high hydraulic conductivity measured from core samples collected and the loss of circulation that was observed throughout much of the drilling process This could be due to the grouting process, which may have resulted in an abundance of grout penetrating into the formation (due to high hydraulic conductivity and destruction of the borehole wall during drilling), which could have reduced the effective hydraulic conductivity and muted any noticeable enhancements that exist. Completion of depth-discrete slug tests or hydraulic tests will be able to assist in better understanding the true formation hydraulic conductivity, although new boreholes will be needed for this.

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References Coleman, T. I., Parker, B. L., Maldaner, C. H., & Mondanos, M. J. (2015). Groundwater flow characterization in a fractured bedrock aquifer using active DTS tests in sealed boreholes. Journal of Hydrology, 528, 449-462. Maldaner, C. H., Munn, J. D., Coleman, T. I., Molson, J. W., & Parker, B. L. (2019). Groundwater flow quantification in fractured rock boreholes using active distributed temperature sensing under natural gradient conditions. Water Resources Research, 55(4), 3285-3306. Munn, J. D., Maldaner, C. H., Coleman, T. I., & Parker, B. L. (2020). Measuring Fracture Flow Changes in a Bedrock Aquifer Due to Open Hole and Pumped Conditions Using Active Distributed Temperature Sensing. Water Resources Research, 56(10), e2020WR027229.

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Figure K1: Photo collage detailing downhole A-DTS testing within NWT01

Photo collage showing: a) Dr. Jonathan Munn splicing cable to prepare the A-DTS cable for deployment; b) Dr. Jonathan Munn preparing to lower the cable into the hole with the weighted cable end in view; c) the set up with the cable running from the borehole to the trailer; d) the trailer setup with the junction box, logger and computer for recording temperature data throughout the test.

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Figure K2: WellCAD montage detailing field data collected from NWT01

WellCAD montage showing lithology, gamma, A-DTS, recovery, RQD, fracture and sample data collected from borehole NWT01 during the August 2019 field episode. This data presentation is similar to that of Figure 5 in the main text, but with additional information from the A-DTS test and slightly different visual representations of the data. The gamma log in this montage has been corrected to account for response muting caused by running the probe through the drill rods.

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