University of Cincinnati

U UNIVERSITY OF CINCINNATI

Date: 5-25-09

I, Justin Sirico Stroup , hereby submit this original work as part of the requirements for the degree of:

Masters of Science in Geology

It is entitled: Glacial Lake Ojibway, lacustrine stratigraphy and implications for drainage

Justin S. Stroup Student Signature:

This work and its defense approved by:

Committee Chair: Dr. Thomas Lowell Dr. Andy Breckenridge Dr. Warren Huff Dr. Madeleine Briskin

Approval of the electronic document:

I have reviewed the Thesis/Dissertation in its final electronic format and certify that it is an accurate copy of the document reviewed and approved by the committee.

Committee Chair signature: Dr. Thomas Lowell Glacial Lake Ojibway, lacustrine stratigraphy and implications for drainage

Justin Sirico Stroup

B.S., Lehigh University 2007

A thesis

Presented to the University of Cincinnati

In partial fulfillment of the degree of

Master of Science

In the Department of Geology

College of Arts and Sciences

2009

Committee Chair: Dr. Thomas V. Lowell ABSTRACT

Some short term climate reversals on the order of centuries are perceived to be generated by coupled feed backs in individual systems. It has been hypothesized that a significant pulse of fresh deglaciated water could be responsible for the capping of the upwelling and gyre circulation in the North Atlantic Ocean consequently forcing a cooling in global temperature and a climate reversal. The catastrophic drainage of Lake Ojibway into the North Atlantic is a proposed trigger for the 8200 Cal. BP year cooling event. The objective of this study is to identify the stratigraphic signature of lake drainage and to assign some chronology to the stratigraphy. A stratigraphic record was developed based on cores from eleven lakes in transect from northeast Ontario 240 km southeast into the province of Quebec. The interpreted stratigraphy consists of a post Cochrane re-advance, ice proximal and distal sedimentation before final drainage and post drainage landscape stabilization. This stratigraphic record of Lake Ojibway provides a unique record which may be incorporated into a larger data set. Refined chronostratigraphic results may be integrated into larger studies with the objective of demonstrating a causal relationship between lake drainage, the capping of the North Atlantic circulation and a reversal in climate regime within the warmer Holocene.

I II ACKNOWLEDGEMENTS

I would like to thank the members of my committee, Thomas Lowell, Warren Huff, Andy Breckenridge and Madeleine Briskin for their mentorship and help in revising this manuscript. Special thanks to Joanne Ballard for discussion and help in the laboratory and to Tammy Gerke for help with XRF geochemistry. I would like to thank all those who have supported me both directly in this work and indirectly as friends. Thanks to Limnological Research Center at the University of Minnesota for help in initial core processing and to Erik Brown at the University of Minnesota, Duluth for XRF core scans. I would like to express gratitude to NSF for their support through grant number EAR0643144 and to Sigma XI and GSA for their grants for graduate research.

III TABLE OF CONTENTS Acknowledgments ...... III List of figures ...... VI List of tables ...... VII Appendix ...... IX Introduction ...... 1 Proposed climate change triggering mechanism ...... 1 Scope...... 3 Background and previous Work ...... 3 The formation of Lake Ojibway and Early works ...... 3 Cochrane Re-advance ...... 4 Methods ...... 6 Site Selection and core recovery ...... 6 Analysis ...... 8 Initial core processing ...... 8 Core imaging ...... 8 High-resolution Magnetic Susceptibility ...... 8 Density and Low Resolution Magnetic Susceptibility ...... 8 Gamma density ...... 8 Rhythmites Varves ...... 8 Chronology 14C dating ...... 9 X-ray Diffraction (XRD) ...... 9 Loss on Ignition ...... 9 Grain size ...... 9 Sediment Chemistry X-ray Florescence ...... 12 Results ...... 12 Stratigraphy: Reference sections ...... 12 Physical Core descriptions ...... 15 Higher elevation - Reid Lake ...... 15 Lower elevation - Lillabelle Lake ...... 17 Stratigraphic summary and basin correlation ...... 19

IV Other cores ...... 19 Core analyses ...... 22 Magnetic susceptibility (K) and Density ...... 22 Loss on ignition ...... 22 XRF Chemistry ...... 24 Chronology 14C ...... 27 Investigation of the pellet unit ...... 30 Pellet unit summary and discussion ...... 33 Investigation of the laminated unit ...... 36 Laminated unit summary and discussion ...... 39 Discussion ...... 40 Stratigraphy leading up to the Cochrane re-advance ...... 40 Stratigraphy above the Cochrane up to drainage ...... 40 Identification of drainage ...... 44 Drainage hypotheses ...... 45 Conclusions ...... 46 References Cited ...... 48 Appendix ...... 50

V List of figures

Fig 1. Study area location and background ...... 2 Fig 2. Idealized stratigraphy ...... 5 Fig 3. Reconstructed digital elevation model (DEM) for isostatic rebound ...... 7 Fig 4. Reconstructed paleo water depth model ...... 11 Fig 5. Image of varve, pellet, and laminated units ...... 13 Fig 6. Simplified stratigraphy ...... 14 Fig 7. Reid lake detailed section...... 16 Fig 8. Lillabelle lake detailed section ...... 18 Fig 9. Stratigraphic correlation ...... 20 Fig 10. Gardiner Lake stratigraphy ...... 23 Fig 11. XRF chemistry along core plots ...... 25 Fig 12. XRF chemistry bivariate plots of units ...... 26 Fig 13. Time distance diagram ...... 29 Fig 14. Thin sections of pellets ...... 31 Fig 15. IRD and sedimentation rate ...... 32 Fig 16. Along core XRD, Lillabelle Lake ...... 34 Fig 17. Laminated Unit ...... 37 Fig 18. Grain size plot ...... 38 Fig 19. Conceptual model ...... 41

VI List of tables

Table 1. Coring locations, modern water depth and reconstructed water depth ...... 10 Table 2. Chronology, 14 C ages ...... 28

VII Appendix

Stratigraphic Lake Core Summary Sheets

Appendix Information...... 50 South Fraserdale Lake ...... 60 Kettle Lake...... 67 Gardiner Lake ...... 74 Lillabelle Lake ...... 87 Withington Lake ...... 100 Joseph Lake ...... 104 Rilling Lake ...... 108 Frederick House Lake ...... 111 Barber’s Bay ...... 115 Reid Lake ...... 121 Petit lac Dufresnoy ...... 128 Petit lac Dufresnoy Varve Counts ...... 132 Images of material dated ...... 142

VIII Introduction

Short term changes in past global climate have been widely recognized, but the mechanisms that cause rapid changes are not well understood (Rahmstorf, 2002). The 8200 cal. BP year climate event is an abrupt cooling thought to be a result of gyre circulation and thermohaline circulation slowdown of in the North Atlantic Ocean (Clark et al., 2001; Ganopolski and Rahmstorf, 2001;

Clark et al., 2002; Alley and Agustsdottir, 2005; Ellison et al., 2006; Hill et al., 2006). One proposed triggering mechanism of this event is a pulse of fresh water attributed to the rapid drainage of glacial Lake Ojibway (Fig. 1) (Barber et al., 1999; Bauer et al., 2004). Studies in and around Hudson Strait, the proposed drainage pathway of Lake Ojibway, have helped to understand the stratigraphy and chronology of the region in order to track the drainage history

(Andrews et al., 1996; Barber, 1999); however, there has been much less focus on the lake basin itself.

A variety of studies have used mapping and modeling exercises to examine ice position (Dyke,

2004) and retreat rates (Antevs, 1925; Teller et al., 2002) within glacial lake Ojibway, as well as the basins’ geometry, isostatic rebound (Veillette, 1994), lake volumes (Leverington et al.,

2002). Descriptions of the region geology and stratigraphic work pertating to the lake ojibway basin have also been conducted (Coleman, 1909; Antevs, 1925; Antevs, 1928; Hughes, 1959;

Skinner, 1973; Hardy, 1976; Hardy, 1977; Paulen, 2001). Additionally marine records have been compiled to reconstruct the Lake Ojibway history and evolution through time (Teller et al.,

2002).

Despite these works there are discrepancies with regards to the timing and characterization of drainage (Alley and Agustsdottir, 2005). It is unclear whether the drainage of Lake Ojibway

1 y a

a o

P Ice Margin

Lake Agassiz e

g 14 r

a 8 k C BP

P ain

12 Dr

Study Lake Ojibway Area

Fig. 1 Map after Barber et al. (1999) showing the hypothesized drainage route of Lake Ojibway through Hudson Strait and into the North Atlantic Ocean. Laurentide Ice Sheet position and locations of Lakes Agassiz and Ojibway are reconstructed from Dyke, 2004. The box south-southeast of James Bay outlines the study area shown in ﬁgure 3.

2 occurred a one event(Barber, 1999) or as a series multiple of smaller incidents (Antevs, 1925;

Antevs, 1928; Skinner, 1973; Hardy, 1977). This study develops a stratigraphic record in the

Ojibway basin —the source of the water— to clarify the final drainage stratigraphy, develop a

history of drainage and to work towards unifying the previous works in the basin (Coleman,

1909; Antevs, 1925; Antevs, 1928; Hughes, 1959; Skinner, 1973; Hardy, 1976; Hardy, 1977;

Paulen, 2001). This is the first study to use lacustrine sediment cores record to capture the

stratigraphy in the basin. It was thought that the stratigraphic record could be directly correlated

with other work in the basin and chronology could be employed to test the relationship between

drainage and the 8200 cal. BP year event; however, correlation with other records is limited and

one additional stratigraphic unit was found in the lacustrine record. This study employs

stratigraphy, sedimentology, magnetic susceptibility, density and X-ray florescence chemistry to

characterize lacustrine sediment cores from eleven lakes in a transect across the Lake Ojibway

basin.

This work expands our knowledge of the post-Cochrane re-advance stratigraphy with a sequence

of units from the terminal Lake Ojibway phase through final drainage and develops a

stratigraphic sequence for late lake phases up through final drainage. Finally, possible models for

drainage based on the new stratigraphy will be discussed. This work may provide a foundation

that can be used in the identification of drainages of other large or pro-glacial lakes.

Background

As the Laurentide ice sheet retreated over Canada a series of ice dammed lakes formed. One

occurred south-southeast of James Bay and is called Lake Ojibway (Coleman, 1909; Antevs,

1925; Veillette, 1994) (Fig. 1).

3 It is thought that there were at least two stages of glacial lakes during the early phases of retreat.

The first, Lake Barlow, was described by Wilson (1918); as the ice sheet retreated further north crossing a topographic divide it was ultimately renamed Lake Ojibway (Coleman, 1909). This was later confirmed by examining the change in outlets (Veillette, 1994) however, there is no good stratigraphic record of this lake expansion (Antevs, 1925).

Early works provided initial sediment descriptions (Bell, 1879; 1883; 1885; 1892; Coleman,

1909; Antevs, 1925; 1928). These studies recognized the presence of a large lake, developed a varve stratigraphy, and provided insight into ice retreat rates from outcrops. The reader is referred to Antevs 1925, 1928 for the established varve record and the detailed criteria for the identification of varves and rhythmites. This record chronicles the stratigraphy after lake formation through the Cochrane re-advance but does not contain the uppermost stratigraphy because the record was assembled from outcrops which do not record the events subsequent to the drainage event. The upper parts of these terrestrial sections were presumably eroded in the post drainage basin.

There is evidence that during overall ice sheet retreat there were periods of re-advance into Lake

Ojibway. The Cochrane re-advance on such resurgence that is widely recognized (Skinner, 1973;

Hardy, 1976; 1977; Paulen, 2001) (Fig 2). Lesser re-advances have been suggested: the Rupert and Cochrane II defined by varve and lamination thickness patterns (Skinner, 1973; Hardy,

1976; Hardy, 1977). It has also been observed that varve units associated with Lake Ojibway are stratigraphically above the Cochrane advance (Paulen, 2001). These studies establish a record within the lake basin and provide an opportunity and context for this study to extend the stratigraphic record through the final drainage of Lake Ojibway.

4 (North) PD (south) Coring Loactions Deeper water RI shallower water WI RD LB JH SF GA

Drainage? Tyrrell Sea Rupert ? Cochrane II ? Cochrane I

Matheson Till Varves Pellet unit Organic Lacustrine Earlier IRD

5 Diamicton Glacial - Interglacial Laminated unit Tyrrell Sea Sequence continue silt and clay Sand Diamicton

Fig. 2 Idealized stratigraphy of the lake Ojibway basin compiled from (Antevs, 1925; Antevs, 1928; Skinner, 1973; Hardy, 1976; Hardy, 1977; Paulen, 2001). As a result of the size of the Ojibway basin different patterns in sedimentation occur as the ice sheet retreats. Underlying the Ojibway sequences there are previous glacial, interglacial cycles which outcrop to the north (Skinner, 1973). Above these earlier sequences, till underlies the Lake Ojibway clays and local bedrock highs sometimes protrude. In the ice sheet retreat phase, Lake Ojibway clays were deposited in front of the ice margin. The ﬁngers of till in the Ojibway clays to the north depict the proposed re-advances of the ice sheet into the basin (Hughes, 1959; Hardy, 1976; Paulen, 2001). Stratigraphically above, towards the north, there is a marine incursion (Tyrrell sea) at lower elevations and to the south, at higher elevations, Lake Ojibway sediments. The units above are the pellet unit and laminated unit which are characterized in this research. The coring locations are located on this diagram showing their interpreted position for contextual reference. All of the cores penetrated into the Ojibway clays. SF, GA, LB, and JH fall within the Cochrane re-advance limit where as WI, RD, RI, and PD are outside of the limit. Currently, there is not enough dating to determine if the sedimentary units are time transgressive or contemporaneous. No section has been recovered that allows correlation of the varves strtigraphicaly below the Cochrane re-advance to the stratigraphy above the Cochrane re-advance. This missing link in the stratigraphy, results in an assumption about the time relationship of the varve stratigraphy represented in this diagram shown to span the Cochrane re- advance. Methods

Site selection and core recovery

The coring locations were chosen on the basis of: 1) proximity of Antevs’ sections, 2) a reconstructed paleo lake bathymetry corrected for isostatic rebound (Fig 3); 3) consideration of modern surrounding topography and bathymetry to avoid slumping or post-depositional disturbance; 4) lakes with greater water depths were preferred to increase the likelihood of glacial varve recovery and avoid depositional hiatus; 5) proximity to paleo-shoreline or topographic highs, possible islands, to increase the potential for recovery of terrestrial organic material for 14C dating (Fig. 3).

Another factor influencing the selection of coring sites was the recognition of the Cochrane re- advance which could truncate the lower lake record and generate a different stratigraphy than sites further to the south outside its influence (Hughes, 1959; Hardy, 1976; Paulen, 2001). To detect its influence additional lake cores were taken on both sides of the proposed limit. The hope was to increase the chance of getting a record that allows the stratigraphy from below the

Cochrane to be correlated with that above (Fig. 3). The coring locations inside the Cochrane limit contain stratigraphy above the Cochrane till (Paulen, 2001). This “upper stratigraphy” may contain Lake Ojibway sequences that extend the stratigraphic record from pre to post drainage.

Eleven lakes were cored in Ontario and Quebec along a transect over a distance of approximately

240 km from northwest to southeast (Fig. 3). Data on core location, modern water depth and reconstructed water depths are presented in Table 1. Generally, the paleo-water depths of the

6 Modern Elevation (m asl) HIgh: 680 James Bay Low: -133

Terminal Lake Ojibway (maroon)

A Cochrane I limit

South Fraserdale Kettle Withington Gardiner Lillabelle Joseph Early Kinojévis (blue)

Reid Rilling A’ Lake Petit du Fresnoy 0 100 200 Ojibway outlets Kilometers

Fig. 3 Paleolake reconstruction of Ojibway shore lines accounting for isostatic rebound, shore line mapping and Tyrell sea level by Andy Breckenridge (Breckenridge et al., 2008) after (Dredge and Cowan, 1989; Dyke and Dredge, 1989; Vincent, 1989; Veillette, 1994). The assumption is that the Ojibway topography immediately after drainage should be identical to the earliest Tyrrell Sea topography and that the marine limit features formed immediately after Ojibway drained every- where in the basin. Note: that all published shoreline reconstructions of Lake Ojibway have steeper slopes than those at the Tyrrell Sea limit. This makes the reconstruction a minimum for Lake Ojibway water levels if the basin was always an open basin.This reconstruction is approximation used to help in understanding the context of the coring locations within the greater Ojibway Basin. The coring sites are labeled; their distribution spans the Cochrane limit indicated by the black line (Breckenridge et al., 2008). It may be also be important to note that the southern sites are in high topography and with little bays and channels which inﬂuence there sedimentation regimes. The transect from A to A` is the orientation of the stratigraphic columns in ﬁgures 4 and 10.

7 coring sites followed the regional slope but there were some differences (Fig.4). Cores were collected until refusal with the Livingston and Bolivia piston coring systems and stored under refrigeration until core processing.

Analysis

Initial core processing

The cores were processed at the University of Minnesota Lac Core laboratory, Minneapolis in accordance with their procedures (Smol, 2001; Schnurrenberger et al., 2003; Breckenridge,

2007). A Geotek multi-sensor core logger (MSCL) was used to measure: density, and magnetic susceptibility. The MSCL was used on the whole core at 0.5 cm resolution although the magnetic susceptibility loop averages over ~6cm. Cores were then split into working and archival halves after which high-resolution images of the cores were taken (see data repository) and the initial core description was conducted. The GEOTEK XYZ Multi Sensor Core Logger (XYZ MSCL) was used to collect high-resolution magnetic susceptibility data on split core halves. Magnetic susceptibility of the core sediment was measured in SI units with a resolution of 1.26x10-6 and a spatial resolution of 1 cm. One half of the core was archived in refrigeration at the, National

Lacustrine Core Repository, Lac Core facility.

Rhythmites and Varves

Rhythmites and varves were found in the recovered cores. They were distinguished using the criteria from (Antevs, 1925; Lamoureux, 2001). Varves were counted and measured with Image

J., image analyses software, using the high-resolution core scans calibrated for scale and color.

8 Chronology

Radiocarbon dating of plant macrofossils helped date the stratigraphy. When no visible macroossils samples were present, core sediment was sieved at 1 cm intervals. Sediment samples were disaggregated and sieved with a 350 µm mesh. Deionized water was used to rinse the samples before drying, weighing and storing in glass vials. Samples were sent to the National

Ocean Science Accelerator Mass Spectrometry Facility (NOSAMS) for dating.

X-ray Diffraction (XRD)

Sediment samples were characterized using a Siemens D-500. Oriented powder diffraction scans of the clay fraction were ran from 2-32 degrees two theta at 0.5 degrees step size and 1 second count using copper K-alpha radiation.

Loss on Ignition (LOI)

Crucibles were dried and massed. Sediment plugs (~1cc) were collected at 2 cm intervals down core. Samples and crucibles were massed and dried at 110o C for a minimum of 6 hours. The samples were re-massed before firing at 550o C for 1 hour, this step removes the organic material. After cooling samples were massed again and then re-fired at 1000o C to remove the

Carbonate. The samples are massed a final time. The LOI (550o C and 1000o C ) at is expressed in percent of the original dry mass.

Grain size

Grain size and distribution was measured using with a Coulter LS230 Variable Speed Fluid Module Plus grain size machine. The sample was collected, put in to a test tube, 5-10 ml of water was added and the sample was stirred to aid in disaggregation. Samples were then solicited for 15 minutes, then stirred/ dis-

9 CoringsitelocationandLakeinformation ReconstructedLakeOjibwaywater depths(m)relativetothemodern Modern Modern LRC elevation Water lakesurface Lakename Name Latitude Longitude (m) depth(m) EarlyKinojevis TyrrellLimit SouthFraserdaleLake SF07 49.772813 81.523539 227 1.4 99 69 KettleLake KET07 49.457418 80.438582 278 9.9 32 17 GardinerLake GA07 49.300833 81.031419 239 4.6736 70 54 LillabelleLake LB07 49.102125 81.026267 244 2.36 59 45 WithingtonLake WO08 48.93762 80.64532 293 3.35 16 5 JosephLake JO08 48.91899 80.84835 270 6.71 30 22 RillingLake RI08 48.65384 80.59765 264 15.24 26 19 FrederickHouseLake FH07 48.650389 80.883663 272 1.27 18 13 Barber'sBay BB08 48.61496 80.90916 279 14.63 18 13 ReidLake RD08 48.54212 80.79506 271 10.05 14 7 PetitdulacDufresnoy PD08 48.4342 78.97348 278 1.15 24 21 Table 1. Core locations are arranged by latitude from north to south. LRC name is the Lake abbreviation for 10 the individual lakes used by the LRC. The reconstruct water depths were generated from the DEM (Fig. 3). pellet unit. age. As waterleveldroppedshallower basinswillexperiencethedrainageﬁrst. The underlinedsitescontainthe between theearlyandlaterphases. The paleoreconstructionshouldbeaccountedforwhenconsideringdrain- be notedthattheoutletcontrolslakelevels,soasisapproached,therenochangeinwater depths nal phaseofLakeOjibwayshouldhaveareboundsurfaceidenticaltothe Tyrrell Seamarinelimit.Itshould of thisreconstructedshorelineislesssteepthanthePontonreconstruction. The principalassumptiontermi- tion interpolatedfrommarinelimitelevationdataDredgeandCowan,1989 Vincent, 1989. The slope and Hardy, 1979fortheEarlyKinojevisphaseofLakeOjibway. Tyrrell Limitlevelsarebasedonareconstruc- 3. PontonLevelsarebasedonareconstructioninterpolatedfromLakeOjibwayshorelinedata Vincent Fig. 4ReconstructedLakeOjibwaywaterdepths(inmeters,relativetothemodernlakesurface) from Figure

Water depth (m) -160 -140 -120 -100 -80 -60 -40 -20 0 804. 904. 50.0 49.5 49.0 48.5 48.0 Tyrrell Limit Early Kinojevis PD RD BB FH RI Latitude 11 JH WI LB GA KET SF agitated and sonicated for 5 minutes. The samples were then run on the Coulter Counter, three runs at 60 seconds were averaged.

Sediment Chemistry

Energy dispersive X-ray florescence (XRF) geochemical data was collected using an ITRAX core scanner at the University of Minnesota Duluth. This instrument is capable of 0.2 mm resolution and incrementally scans split cores recording optical, radiographic and elemental changes (Croudace et al., 2006). It is somewhat less accurate than traditional wavelength dispersive methods of XRF because changes in core characteristics such as grain size and density can effect measurements, however this instrument provides a rapid, high-resolution nondestructive characterization of elemental concentrations of the sediment (Jenkins, 1999;

Croudace et al., 2006; Rothwell and Rack, 2006; Carlson et al., 2007). A sampling interval of 4 mm was chosen so centimeter scale changes could be resolved. The XRF chemistry was used as another line of evidence for establishing the stratigraphic linkages between different units.

Results:

Stratigraphy: Reference sections

In the lake cores recovered, there were differences in stratigraphy across the basin. It was expected that varves would be recovered based on the existing records in the central part of the basin however what might be above the varves was an unknown because the terrestrial outcrop record was truncated. In addition to the varves, two additional units, a ‘pellet’ unit, and a laminated unit were recovered (Fig 5). These will be discussed below but first the general stratigraphy recovered will be described.

12 South Fraserdale Lake SF07-1A-3L-1 laminated unitmayappearmottled(Fig.16) the appearanceofunitsfromlaketoforexample from SouthFraserdaleLake. There aresomedifferences in Fig. 5Examplesofthevarve,pellet,andlaminatedunits Varve Unit 13 Pellet Unit Laminated Unit Idealized Stratigraphy A A’ Unit Unit 5 5 Organic Lacustrine

4 4 Laminated silt, clay & sand Pellets laminated 3 matrix 2 Rhythmites Thining 2 Rhythmites

LB RD

Changes in water depth and bathometry Cohrane re-advance limit

Fig. 6 Simpliﬁed general stratigraphy showing the differences in stratigraphy between the coring sites from A to A` across the basin. The columns are also labeled by lake: LB – Lillabelle Lake and RD – Reid Lake. The sites to the north “A” are interior to the Cochran re-advance and lower in elevation, deeper water depths. Whereas the locations to the south are shallower and outside the Cochrane re-advance. It is unclear if the stratigraphic differences are a function of water depth, and or batho- metric geometry differences illustrated by the DEM in Fig. 3.

14 There are two different stratigraphic sequences captured in the lakes cored in the Ojibway basin

(Fig. 6). The first is represented by Lillabelle Lake, is within the proposed Cochrane re-advance limit and lower in elevation, which is equated with greater paleo-water depth. The second, Reid

Lake, is outside the Cochrane and higher in elevation (shallower Lake Ojibway water depths)

(Fig 3). The units are primarily defined by changes in visual stratigraphy and further characterized with magnetic susceptibility, gamma density and XRF chemistry. The stratigraphic sequences are similar across the Ojibway basin; however, there is an additional unit, the pellet unit, within the Cochrane limit,

Physical core descriptions (Higher elevation) Reid Lake

The stratigraphy of Reid Lake is detailed in figure 7. The general stratigraphy from the bottom beginning with: centimeter-scale rhythmites couplets alternating between dark brownish gray clay to tan gray silt and sand (unit 2.1). The sandy laminations exhibit poor internal sorting but are distinct from the silty clay laminae. These rhythmites have a regular pattern with distinctive couplets. As a result, these are interpreted to be varves based on their appearance (Antevs, 1925).

The varves then thin over 20 cm (see appendix). Above this, unit 2.3, silty sandy coarser (cm scale) contorted laminations are present and then (cm scale) rhythmites develop. In some cases, there are sections of rhythmites at high angle relative to horizontal rhythmites below and above.

Smear slides show a mineral composition dominated by quartz, then calcite, and some hornblende, biotite and feldspar. Above, in unit 2.4, the rhythmites become contorted with additional dark gray-brown clay in the matrix. This unit has wavy high angle contorted silty sands with a clay matrix in two coring thrusts and is homogeneous in the other one. The thicknesses vary in the different thrusts (25 cm, 20 cm and 15 cm) and the stratigraphic depths

15 Reid Lake Composite Section 10

11 Unit Description Interpretation 12 5.1: Dark brown sapropel 5.1: Similar to modern conditions 6,950 14C age 5.2 : Dark gryish brown 13 silty peat 5.2: Landscape stabilization 5.1: Light brown gray mas 14 sive to faintly lami 5.1: Introduction of nated sapropel organics, set of biotur bation 15 4.1: Dark gray to light gray rhythmically 4.1: Laminated unit post laminated clayey silt drainage or lake level 16 lowering 4.1: Dark gray calcareous quartzose clay, with 4.1: Disturbed rhythmites

Depth (m) contorted laminations Cochrane influence ? 17 2.4: Convoluted, lami 2.4: Turbidite nated gray silt and 18 sandy silt 2.3: Higher sedimentation 2.3: Convoluted coarser, strat of Cochrane 19 sandy silt re-advance?

2.2: Thinning varves 6.2: Ice sheet retreat

20 2.1: Gray clayey silt and 2.1: Ice proximal Varves silt rhythmites.

21 2.1: Laminated graysilt 2.1: Ice proximal Varves and sandy silt

22 2.1: Darker fine grained 2.1: Ice proximal Varves beds than unit 8 lami nated dark gray silty 23 clay and gray sandy 0 50 100 150 200 1.0 1.4 1.8 2.2 silt Volume Magnetic Density Susceptibility (gm/cc) (SI Units) Fig. 7 Generalized stratigraphic section for Reid Lake. Detailed core log with images can be found in the appendix.

16 are not the same in each thrust changing by ~1 m. The resulting interpretation from these observations is that unit 2.4 could be a debris flow. Unit 4.1 is light brown laminated clayey silt that becomes massive before grading into unit 5.1 a brownish gray sapropel. The stratigraphy from Reid Lake has glacial lacustrine thinning varves, then rhythmites before the laminated unit.

This stratigraphy may be recording Laurentide Ice Sheet retreat manifest in the stratigraphy by the thinning varves. Then the Cochrane re-advance would be one explanation for the increased sedimentation and thickening rhythmites. Finally, a drainage or lake lowering even may have occurred represented in the stratigraphy by the laminated unit.

(lower elevation) Lillabelle Lake

The northern stratigraphies are represented by Lillabelle Lake (Fig. 8). The stratigraphy for the bottom up ward is a dark grey diamict (unit 1). Above this, in unit 2.1, dark to light gray clays and silts dominate, but sand to pebble size particles are present. There are rhythmites with coarse

( < 1 cm) and fine (1 mm) scale contorted laminations with little to no regularity in thickness.

Throughout the sediment, pea sized inclusions of sand and clay are also incorporated in the laminations of unit 2.1. In unit 2.2, light gray silts and sands to dark brownish gray silts and clay form repeating rhythmites. The rhythmites in unit 2.2 grade upward from coarser to finer with sharp contacts between the upper fine dark clay and the coarser lighter gray sandy silts. They are interpreted as varves. Visually, the varves decrease in thickness from < 8 cm to less than 0.5 cm.

There are a total of 26 varves in the thinning sequence.

In unit 2.2, the varves thin up section and contain sub-rounded (mm scale) pellets of silt, sand, and clay which continue into unit 3 (the pellet unit), examined in detail below. Unit 3 has a very finely laminated matrix of gray brown clay with pellets of sand, silt and clay, that makes a sharp

17 Lillabelle Lake Composite Section 3 9,810 14C age Unit Description

5.1: Dark black brown sapropel

5.3: Light tan gray layers of sand 4 5.3: Laminated, light gray silty sand

4.1: Massive, grayish brown silty faint laminations (mostly silt) 9,740 are apparent towards 14 5 C age the base of unit

3: Pellets of silt to sand faintly 5 laminated matrix

2.2: Gray silt and dark gray 6 brown clay, thinning varves

2.1:Convoluted, laminated gray silt

Depth (m) and sandy silt

1: Dark gray diamic 7

10 -50 0 50 100 150 200 0.5 1.0 1.5 2.0 2.5 3.0 0 10 20 30 40 50 Volume Magnetic Density LOI Susceptibility (gm/cc) % Organic (SI Units) % Carbonate Fig. 8 Generalized stratigraphic section for Lillabelle Lake. Detailed core log with images can be found in the appendix. Magnetic susceptibility decreases as organic content increases. The Green line represents the percent composition of the organic component of the sediment using loss on ignition (LOI) at 550o C and the red line is the percent carbonate (LOI) at 1000o C.

18 contact with unit 4.1. In unit 4.1, silt concentration increases and fine laminations (mm scale) are visible. The laminations are difficult to distinguish up core because they become massive to mottled and finally homogenized. A sharp contact marks the transition to unit 5.3, a gray sand and silt containing visible aquatic material. This unit grades upward into unit 5.1 a laminated dark brown diatomaceous sapropel over a few centimeters before becoming a massive sapropel which is lighter brown in color.

Stratigraphic summary and basin correlation

A lithostratigraphic correlation can be made with nine cores based on the generalized sedimentologic patterns (Fig. 9). The laminated unit is present in all of the cores and was used to tie the records together for comparison. In some locations the recovered varves were not well preserved and they are at high angles, with unconformities interspersed. We interpret the former to be reworked by slumping.

There two stratigraphic records that do not match: Barbers Bay and Frederick House Lake. The

Barbers Bay record did not yield glacial lacustrine sediment after 22m of organic material was recovered and Frederich House Lake was highly disturbed with many unconformities which are interpreted as slumping. Frederick House Lake was chosen because it was located near Antevs’ sections and might have provided stratigraphy that could be correlated to the established varve record.

Other cores

There are 2 locations that may be used to add greater detail to the lake history and to stratigraphic patterns pertaining to the Cochrane advance, Rilling Lake and Petit Lac Dufresnoy.

19 Petit du lac Dufresnoy

Kettle Reid Lake Rilling Gardiner South Fraserdale Lillabelle Joseph A Withington A’

North South

Vertical scale

012Meters

Organic Lacustrine Sand 6 meters Laminated unit Pellet unit Varves Diamict Cochrane Ice proximal lake sediment Proposed drainage Limit Transect

Fig. 9 Generalized correlation by stratigraphic pattern of lake core stratigraphy recovered. Transect line corresponds to Figure 3. The Blue line resents the contact of the Ice distal pellet unit. Note the purple tie-line is the proposed drainage contact and the laminated unit above is present in all of the lakes. The ice proximal unit refers to diamict, or Lake Ojibway sediments that are irregular and / or disturbed.

20 The most southern site is Petit Lac Dufresnoy (Appendix). Toward the bottom of the section there are at least 3 unconformities in the varves which are at opposing angles. Up core a blocky texture is sometimes visible in the varves. The top of the varves thin and become wavy over 5 cm. Above this there is a 10 cm section devoid of visible stratigraphy followed by thin varves (1

> 0.5 cm scale) that thicken to 1 cm scale followed by another unconformity. The upper varves recovered in this section correlate with the Antevs section ending at varve (~1529) this indicates the section is from older Ojibway stratigraphy (Appendix). Above the varves, the laminated unit is thick (3.8 m) with very sparse organics, and then the sediment becomes darker, a likely indication of an increase in the organic content. This core has the longest recovery of the laminated to mottled sediment and qualitatively has less silt and sand than the other cores. These characteristics are a result of the higher surrounding topography and larger catchment. This record is important because the Ojibway varve record is truncated by an unconformity with the laminated unit present above.

Rilling Lake does not have a stratigraphy that is similar to the other lakes (Appendix). The paleo water depth is ~62 m. This is about the mean of all sample sites. There are rhythmites throughout the core. they thin up core form < 7 cm to > 2 mm internal to these there are fine laminations of varying thickness from ~1 cm to ~1 mm. If the larger scale rhythmites are varves they have a different appearance than any others recovered. They have a very large coarse component (~5 cm) and a thin clayey cap (~0.5 cm). It is unclear what would cause such low clay content and high clastics other then proximity to the sediment source. Above the rhythmites, there is a grading contact upward with inter-fingering organics over 30-40 cm suggesting a continuous and possibly gradual change from classic to organic sedimentation.

21 Core analyses

Volume Magnetic susceptibility and Density

The general patterns of magnetic susceptibility and gamma density are the same for all the cores recovered. Magnetic susceptibility tracks changes in magnetic grain concentration, mineral grain size, and density. From the base of the stratigraphy, the magnetic susceptibility is variable in the clastic units (~50 SI). The magnetic susceptibility reflects changes in sedimentation associated with the rhythmites. Higher susceptibility is measured in the coarser grained part of the couplets

(~60 SI) and lower values in the fine portion (~20 SI). The magnetic susceptibility then decreases over 20-40 cm into the organic rich units (~4 SI). The transition from clastic to organic sedimentation usually occurs over several centimeters indicative of a gradual change (Fig. 7 from

14.1 m to 14.5 m).

The wet bulk density has a similar pattern to the magnetic susceptibility. The density follows changes in grain size in the couplets with higher density (2.1 gm/cc) in the fine grained sediment.

Density decreases up core from (~2 to ~1.4 gm/cc) corresponding to the increase in organic material and diminishing clastic sedimentation.

Loss on ignition (LOI)

Loss on ignition is a proxy for the percentage of organic and carbonate material relative to the total sample mass(Dean, 1974). The changes in loss on ignition is for the stratigraphy is exemplified in Gardiner Lake (Fig 10). At the base of the section, the ice proximal varves fluctuate from ~ 10% to ~20% LOI 1000o C (carbonate). There are changes in the carbonate concentration which are dependent on whether clay (~10%) or silt (~24%) was sampled. There is a rapid decrease over 4cm in the pellet unit to ~4% before, increasing to ~11% in the laminated

22 Gardiner Lake Composite Section Unit 4 Description Interpretation

5.1:Massive dark 5.1:Similar to brown sapropel modern 5 conditions

5.1:Laminated 5.1: Introduc- dark gryish brown tion of sapropel organics, onset 6 of biotur 5.1: Light brown bation gray massive banded sapropel

7 4.1:mottled 4.1: Laminated grayish brown unit post silty clay some drainage or green to black lake level material lamina- lowering 8 tions develpole at Depth (m) te base of the unit

3: Silt and clay 3: Pellets are pellets laminated IRD clay matrix. the 9 pellets are throughout but there are zone of higher abundance 10 2.3: Contorted 2.3: Disturbed coarse, rhythmites sandy silt Cochrane influence ? 11 1: Gray diamic

2.1:poorly sorted 2.1:Drop dark gray silt clay stones and sand with 12 some pebbles 0 50 100 150 200 1.2 1.6 2.0 2.4 2.8 0 5 10 15 20 25 30 Volume Magnetic Density LOI Susceptibility (gm/cc) % Organic (SI units) % Carbonate Fig 10 Generalized stratigraphic section for Gardiner Lake shows a drop in carbonate through the interval de- ﬁned by the pellet unit using (LOI) at 1000o C. The change in organic content was obtained from LOI at 550o C.

23 unit. The drop in carbonate concentration could reflect either decrease in carbonate deposition or carbonate dissolution. Within the varves and clastic units the organic content is very similar

~1.5% with small variations that coincide with changing clay content. In the laminated unit, the organic content increases over 60cm from ~2 % to ~14% and the carbonate content is relatively constant ~12%. Above, in the organic unit, the carbonate tapers down over 55 cm to ~1.9% and the LOI 550o C (organic) concentration remains ~12%. The patterns of organic and carbonate content through the transition from clastic to organic sedimentation are opposite (Fig 10). This reflects a combination of diminishing sedimentation rates and increasing organic productivity attributable to reduced clastic sedimentation in a post drainage environment.

XRF Chemistry

Variations in chemistry are associated with changes in stratigraphy (Fig. 11). The visual changes in varves are mimicked by variations in geochemistry. The chemistry corresponds to the changes in sedimentation of the varve couplets, with increased concentrations of K, Ti, Fe, Rb, and Sr corresponding with the light summer layers and elevated concentrations of Si, Ca, and Zr corresponding with the darker winter layers. In the pellet unit, there are increases in concentrations of Ti, Rb, Sr and a marked decrease in Ca as compared with the units above and below (Fig. 12). The laminated unit above has a homogeneous chemical signature which reflects the sorted grain size. The chemical composition of the laminated unit plots within the composition of the varve unit. This could represent mixing of the varves with less clay content

(winter layers) and more silt (summer layers).

24 M si Pb Sr Rb Fe Ti Ca K Si 3.8

4.0

4.2

4.4 Laminated unit

4.6 LB07-1A-2L

4.8 Pellet unit

Depth ( m ) Depth ( 5.0

5.2

5.4 Varve unit

5.6

5.8 LB07-1A-3L -4 -2 0 2 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 SD 25 7.0 M si Pb Sr Rb Fe Ti Ca K Si 7.2

7.4

7.6

7.8 Laminated unit

8.0

Depth ( m ) Depth ( 8.2

GA07-1A-3B Pellet unit 8.4

8.6 Varve unit 8.8

9.0 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4

Fig. 11 Varve unit couplets have increased concentrations in K, Ti, Fe, Rb, and Sr in summer, and Si, Ca, and Zr in winter. The pellet unit has increases in Ti, Rb, Sr, and a decrease in Ca. Chemical variability in the laminated unit is minimal. Cross Plots: Lillabelle

Winter 5000 120000 Summer 300000 Varve Winter Varve layer layer 100000 250000 Pellet unit 4000 Varve layer 200000 80000 3000 Pellet unit Laminated Laminated Winter

150000 Laminated Ca 60000 Fe Mn Varve Transition 2000 Transition layer 100000 From pellet unit to 40000 Summer From pellet unit to Summer laminated 1000 Pellet unit 50000 Varve layer laminated 20000 Transition Varve layer From pellet unit to laminated 0 0 0 0 2000 4000 6000 0 2000 4000 6000 0 2000 4000 6000 Ti Ti Ti

300000 5000 120000 Laminated Unit Laminated Unit Laminated Unit 250000 4000 100000 200000 80000 3000 150000

Ca 60000 Mn

Fe 2000 100000 40000 1000 50000 20000 0 0 0 300000 Transition 5000 Transition 120000 Transition 250000 from pellet unit 4000 from pellet unit 100000 from pellet unit 200000 to laminated unit to laminated unit 80000 to laminated unit 3000 150000 Ca 60000 Fe Mn 2000 100000 40000 Counts 50000 1000 20000 0 0 0 300000 5000 120000 Pellet Unit Pellet Unit Pellet Unit 250000 4000 100000 200000 80000 3000

150000 Ca 60000 Mn Fe 2000 100000 40000 1000 50000 20000 0 0 0 300000 5000 120000 Varve Unit Varve Unit Varve Unit 250000 4000 100000 200000 80000 3000

150000 Ca 60000 Fe Mn 2000 100000 40000 50000 1000 20000 0 0 0 0 2000 4000 6000 0 2000 4000 6000 0 2000 4000 6000 Ti Ti Ti Counts Counts Fig. 12 Bivariate plots of Fe vs. Ti, Mn vs. Ti, Ca vs, Ti display the chemical signatures of the different units, color coded in stratigraphic order. The compositions of the different stratigraphic units are distinctive. From the bottom up, the varve section at the bottom (green) shows the variation in chemical composition in the couplets, winter and summer layers correspond to the highest and lowest values. The pellet unit above (light blue) is an end member composition with higher counts than the other units. The “transition unit” is the sediment between the pellet unit and the laminated unit. This was separated because the contact grades over several centimeters. The values are in between the pellet unit and laminated unit consistent with the grading contact. Above, the laminated to mottled unit’s data clusters together. The top most graphs are a summary of the different units chemistry. The laminated unit has a chemical composition that appears to represents a mixing of the varve and the pellet unit. This could be achieved by grain size sorting through removal of certain fractions. The Ca concentrations are lower in the pellet unit suggesting removal by dissolution. The patterns hold true for a variety of other elements (Ti: Si ) and are also true for the Gardiner lake core through the same units.

26 Chronology 14C

Developing a reliable chronology in the Ojibway basin has proven difficult because of the scarcity of terrestrial macrofossil material normally used in radiocarbon dating. Aquatic material was used for dating but it was only present in the cores on a limited basis.

The chronology data show a wide span of ages. The results are tabulated (table 2). There are two dates from South Fraserdale on abraded wood fragments of 42,240 ± 370 Cal. BP (OS-67637) and 45,702 ±942 Cal. BP (OS-67639) that are interpreted as re-worked material from the last interglacial. The bulk of the calibrated ages straddle the 8200 Cal. BP year event (Fig. 13). The older ages are more enigmatic, from Lillabelle samples OS-67634 and OS-67638 (11,167 ± 49 and 11,231 ± 28 Cal. BP respectively) and Kettle sample OS-71419 (13,442 ± 110 Cal. BP). The material dated from Lillabelle is a collection of small aquatic plant fragments compiled from a

1cm thick slice of core. Their stratigraphic context is two sandy units just atop the laminated unit. The Kettle Lake sample is a collection of aquatic plant stalks with small leaves attached.

The sample is just above the contact in laminated unit with small bands of carbonate (Apendix).

The other younger dates ranged from 7,743 ± 37 Cal. BP. (OS-71534 ) at Rilling lake to 8,590 ±

21 cal. BP. (OS-71353) at Joseph lake. These dates are all from about the same stratigraphic position at the top of the laminated unit (Fig. 9). The range of ages is much smaller and closer to the proposed climate change event at 8200 Cal. BP yrs. In all, the dates provide a first step in assigning chronology to the stratigraphy recovered, however they should be considered carefully because a hard water correction has not been developed. This may make the ages have an older apparent age. There are not enough dates and the resolution is not high enough to tell whether the laminated unit is contemporaneous at all the sites or if it is time transgressive.

27 Cronology14C

Sample Depth in 95.4 % (2) Relativearea Thrust Lab cal age under Median LakeName Core Thrust (cm) Type Number d13C A Agege Error D14C ranges distribution probability calibration data

SouthFraserdaleLake SF071D1L1 42.544.5 Wood OS67639 24.31 37700 380 990.9 42240±370 ~ ~ Calpal2007_HULU SouthFraserdaleLake SF071D1L1 44.546.5 Wood OS67637 26.09 42300 510 994.8 45702±942 ~ ~ Calpal2007_HULU SouthFraserdaleLake SF07_1D1L1 4041.5 Aquatic OS71350 14.18 7320 25 601 80398181 1 8110 Reimeretal,2004 KettleLake KET071B1L1 4445 Aquatic OS71419 37.65 11550 45 764 1327113506 1 13380 Reimeretal,2005 LillabelleLake LB071B1L1 5859 Aquatic OS67634 36.09 9740 55 704.8 83478481 0.949815 8409 Reimeretal,2006 LillabelleLake LB071B1L1 1618 Aquatic OS67638 36.69 9810 55 707.2 1113811328 1 11226 Reimeretal,2007 JosephLake JH08_1B1L1 78 Aquatic OS71353 33.31 7810 25 624.6 85458631 1 8587 Reimeretal,2008 RillingLake RI08_1C2L1 4142.5 Aquatic OS71534 32.24 7610 45 615.2 1107411251 0.91727 11178 Reimeretal,2009 RillingLake RI08_1C2L1 4041.6 Aquatic OS71351 28.39 6910 30 579.9 76747796 0.977297 7735 Reimeretal,2010 ReidLake RD08_1C2L1 56 Aquatic OS71352 26.85 6950 30 582.1 76897849 0.997373 7776 Reimeretal,2011 PetitdulacDufresnoy PD081A7L1 15 Aquatic OS70563 27.13 7240 40 ~ 79778162 1 8060 Reimeretal,2012 28

Table 2 Ages were calibrated using Calib 5.1 for years BP with two-sigma. The calibration curve used was Intcal04, CALIB RADIOCARBON CALIBRATION PROGRAM* Copyright 1986-2006 M Stuiver and PJ Reimer. wood fragmentsseetable2. from Aquatic plantmaterial. The twooldestarenotincludedinthis plot andareonabraded The rawandcalibratedagesarereportedintable 2. All oftheagesresentedonthisplotcame around the8200Cal.Bpyeareventbutagedistributions aredistinctfromoneanother. plots depictthepossibleagedistributionfromcalibration. Note:themajorityofagesare Fig 13. The calibrated Calendar Age (ka BP) Data 14 13 12 11 10 9 8 7 84 50 49 48 Time-Distance Diagram,OjibwayBasin 14 C agesareplottedbylakelatitudeandage. The 2δdistribution

PD RD RI Latitude

29 JH

KET

SF Investigation of the pellet unit

The pellet unit has a much different appearance than the varves below. The most prominent characteristic are the pellets, which have a variety of different visual characteristics. In thin- section the boundaries are easily seen and are often sharp. Inside, some of the pellets are clasts of sediment with different colors and sizes than that of the pellet itself. Others had internal structures. Fine laminations are common in the fine grained pellet matrix. Often these laminations are rotated in relation to the core matrix laminae (Fig. 14).

The matrix material surrounding the pellets has faint light and dark laminations (mm scale) which are more prominent toward the base of the unit. The laminated matrix material is deflected under many of the pellets, in some cases the laminations to converge. This observation maybe an indication that the pellets are impacting the matrix material. Additionally, the top and sides of the pellets are draped by the matrix material (Fig. 14). This would indicate that the pellets are being progressively covered by the matrix as new pellets are introduced.

The pellet abundance in relation to the matrix also seemed to change up core. To quantify the amount of pellets per volume, density, of pellets in the core, an X-radiograph was used. The number of pellets increases per unit volume (Fig. 15).

The sediment was sieved and some ostracodes, Candona subtriangulata, were found. Their percents in the finely laminated matrix material and delicate nature may suggest in situ burial because transport of this species would likely break its delicate shell.

Geochemically this unit has a distinct signature from the other units in the core. There is a decrease in calcium compared to the sediment in the other units above and below. There is a general increase in the elemental concentration through the pellet unit. The change in calcium is

30 Lillabelle Lake LB07-1A-3L-1

A A`

0.5cm 0.5cm Core depth (7.5-11.5 cm)

B C

0.25cm Core depth (7.5-11.5 cm) Core depth (79 - 82.5 cm) 0.25cm Fig. 14. Thin sections show pellets of D silt, clay and sand. A variety of different internal patterns can be seen including laminations and mixed grain size (image A). In some instances, the laminated matrix drapes over the pellets (images A, B) and others the laminations are deformed below. Some of the pellets have internal laminations (image C). The pellets are also present in the varves just below the pellet

0.25cm unit (image D) and lower in the thicker Core depth (16-20 cm) proximal varves.

31 Lillabelle 07 2 Core 1A, Section 3 IRD Size (mm ) IRD Rate (ct/yr) 0.1 1 10 100 048 0 Unit Pellet

40 Unit Varved 60 32 Section Depth (cm)

024 2610 800 1200 IRD density (#/cm) Radiograph Grayscale Sed. Rate (cm/yr)

Fig 15.Continuous up-section sedimentation through the varve unit into the ‘pellet’ unit is indicated by the presence of IRD throughout. Thinning laminations continue up section suggesting decreasing sedimentation. This is illustrated in the X-raydiograph grayscale plot showing decreasing rhythmites thickness up-section. Continuous up-section sedimentation through the varve unit into the ‘bleb’ unit is indicated by thing varves that transition to laminations and by the presence of IRD. There is apparent increase in IRD density up section. When the tinning varves are extrapolated through the pellet unit a maximum sedimentation rate of 2mm/yr is generated. The overall sedimentation rate is decreasing up-section. Figure courtesy of Andy Breckenridge. evident in both the LOI and XRF data. Further evidence from XRD shows a change in from calcite to dolomite (Fig.16). This could signify a change in deposition. Slow sedimentation rates could account of the disappearance of calcite through dissolution and continued presents of dolomite which is less soluble.

Pellet unit summary and discussion

The varves, immediately below the pellet unit, thin up section and fine laminations continue into the pellet unit. This is inferred to represent decreasing sedimentation rates. The pellets are interpreted to be ice rafted debris (IRD) (Cofaigh and Dowdeswell, 2001). The draping matrix above, depressed laminations below, and internal clasts or laminations all support the IRD interpretation. The laminated transition along with IRD deposition throughout suggests continuous lacustrine deposition. As a result, drainage must not have occurred, Lake Ojibway must still exist and be in ice contact to allow IRD to be transported in the basin. As the ice retreats further north it is predicted that sedimentation rate should decrease. The sedimentation rate is inferred by extrapolation of the thinnest measurable varves through the pellet unit and

IRD density can be measured using X-raydiography (Fig. 15). The apparent density of IRD increases as a result of a decreasing sedimentation rates. However, in actuality, both sedimentation rate and IRD flux decrease. If a minimum sedimentation rate of 2mm/yr is used, deposition of this unit would have lasted ~ 200 years (Fig. 15). The visual description, chemistry data and sedimentation rate suggest that the pellet unit is a slow sedimentation unit, with IRD deposition.

The change in chemistry, namely the reduction in calcium, is consistent with the idea of slow sedimentation rates (Fig. 12). In a slow sedimentation environment calcite would be exposed to

33 XRD

900 LB07-1A3L-1 Quartz/Illite Chlorite

Amphaboles Illite

Chlorite Feldspars Chlorite Chlorite Quartz Illite Amphaboles Dolomite

5A 1000 Quartz/Illite 7A Chlorite Amphaboles SEM Illite Feldspars Chlorite Chlorite images Dolomite Chlorite Illite Quartz Amphaboles

11A 0

1200 Quartz/Illite

Amphaboles 21A Feldspars Chlorite 23A

Illite Dolomite 21A Chlorite Chlorite Amphaboles Quartz Chlorite Illite 0 600

Quartz/Illite Chlorite Amphaboles 23A Chlorite

Illite Feldspars 36A Calcite Chlorite Dolomite Amphaboles

900 CalciteDolomite

Quartz/Illite

Amphaboles

Feldspars Chlorite Chlorite Illite Chlorite Amphaboles

0 1200 Quartz/Illite

Calcite Chlorite

Chlorite Feldspars Illite Dolomite Chlorite

66.5A Quartz Amphaboles Amphaboles Chlorite Illite 0 66.5A 68.5A

71.5A

71.5A 450

Chlorite Quartz/Illite

Chlorite FeldsparsCalcite Illite

Chlorite Dolomite

800 Dolomite

Calcite Illite Chlorite

Feldspars Amphaboles Chlorite

Amphaboles Illite Quartz Chlorite Chlorite Illite

0 1400 Quartz/Illite Fig. 16 Lillabelle core 1A-3L-1 with XRD Amphaboles Feldspars CalciteDolomite samples. Calcite is present in the varves but Quartz Illite diminishes at the transition into the pellet unit. 0 Calcite is absent in the pellet unit. Dolomite is 0 2 4 6 8 10121416182022242628303234 present throughout both units. º2θCuK a 34 the lake water longer before burial where pore waters become saturated with respect to calcite partially protected from further dissolution(Breckenridge, 2007). Dolomite is less soluble so it is still present in the pellet unit where the calcite is absent (Fig 16). The low calcium affects the apparent concentration of the other elements making them higher in the pellet unit. The net effect is an increase in the concentration of the other elements measured.

Geographically the pellet unit is present in only four locations, South Fraserdale Lake, Gardiner

Lake, Lillabelle Lake, and Joseph Lake. These all lay at lower elevations, in an area of the basin that has low laying subdued topography within the Cochrane re-advance (Fig. 3). It is likely that the pellet unit is associated with the rapid retreat of the Cochrane re-advance. The low sedimentation of the pellet unit is representative of ice distal sedimentation. It must be noted that there is not an abundance of IRD in the southern sites. This may be due to changes in the bathymetry where higher or confined parts of the lake are shielded from IRD, where the high topography causes a constriction in the lake, south of which, there are many small bays (Fig. 3).

The pellet unit looks identical to a ‘drainage breccia’ associated with the invasion of the Tyrell

Sea described by Skinner (1973) and Hardy (1976). When considering the IRD, laminated matrix, lack of calcite and presence of dolomite, elevation above the Tyrell Sea limit, and ostracodes this unit is interpreted as a lacustrine member and not a drainage breccia. If it were a

‘drainage breccia’ some indication of flow might be expected such as tails on the pellets, evidence of broken pellet fragments and flow features in the laminations were not observed.

This interpretation is made with the assumption that the units are the same given the distance and elevation.

35 Investigation of the laminated unit

The laminated unit is present in all the cores collected in the Ojibway basin, either above the pellet unit or above varves depending on which part of the basin is being examined. It is likely that this unit was associated with lake level draw down or drainage because of its widespread distribution across the basin. It has a grain size that is better sorted than the other units below and is visually distinctive because of its fine laminations.

The laminated unit is composed primarily of finely laminated (5 mm to >1mm) silts but some clay and sand are also present. The laminae are often bent, some exhibit waviness and others are detached from each other with horizontal gaps (Fig. 17).

The average grain size of the pellet unit is ~8.2 um, which differs from the varve unit at ~11.6 um and the pellet unit at ~5 um. The laminated unit’s grain size distributions encompass all of the sizes, sand size or smaller, found in the other units. This unit is distinguished in grain size because the size distribution has more silt (Fig. 18). This is likely a result of sorting. The changes in grain size from unit to unit is likely driving the changes in chemistry, as certain size fractions are associated with different mineralogy.

The chemistry of the laminated unit is different from the varve and pellet units below. The chemical signature of these units can be seen in figure 12. The composition has no internal trend up core and consistently plots between the chemistries of the summer and winter varves. This is suggestive of mixing of the varve material. The composition of the laminated unit falls within the summer and winter varve layer chemistry. It plots below the average of the two towards the summer layer chemistry because there is more tilt and less clay which affects the chemistry in the laminated unit.

36 Laminated Unit LRC code:

RD08-1C-2L-1 RI08-1B4L-1SF07-1B2L-1 PD08-1A-7L-1

ABCD

2 cm

Fig 17. Images of the laminated unit from different cores. Image A is repetitive of the laminations in many of the lakes. Image B shows the ﬁner laminations in Rilling that become increasingly organic up section with laminations throughout. In Image C laminations are interrupted and discontinuous with some organic material (dark wispy sediment). Image D shows the mottled sediment look just before it becomes homogenized.

37 Grain size contour Plot South Fraserdale 1B2L 0

40 Laminated unit 50 Depth (cm) 60

80 Images overlaid 1A3L 900 Pellet unit

100

120

1 %

130 10 %

Varve unit d10 d50 140 d90

0.1 1 10 100 1000 150 Grain size (um)

Fig. 18 The grain size is resented by contouring the size distributions plots. The darker colors have greater abundance in percent of the whole sample. The major size fractions are: closed circle (d10), open circle (d50) and the triangle (d90). The differences in grain size correspond to the stratigraphic units. In south Fraserdale Lake the average grain sizes are: varves ~11.6 um, pellets ~5 um and laminated ~8.2 um. In the laminated unit also has a coarse fraction related to trace organics which can be seen macroscopically as the dark spots in on the images. The sand unit at the top of the core may represent a drying event.

38 The laminated unit is interpreted to be a reworking of sediment in the Lake Ojibway basin.

Some possible mechanisms are loess, wave action, surface erosion processes and or density flows. The thickness of the unit is variable (30-80 cm) but are all similar with the exception of

Petit Lac Dufresnoy (3.8 m) (Apendix). The difference in thickness at Petit Lac Dufresnoy maybe a result of larger basin size and higher surrounding topography, providing a higher sedimentation rate. The transition from the laminated unit to the unit to the organic unit above has two different appearances. At Rilling Lake, the transition is laminated. In all of the other cores, the top of the laminated unit becomes mottled in texture as organic material becomes increasingly abundant finally the sediment becomes dark in color. The prevalence of the laminated unit and suggestion of mixing in all the coring sites needs to be considered carefully when interpreting lacustrine stratigraphy.

Laminated unit summary and discussion

There are several possibilities for the interpretation of the laminated unit. Some hypotheses for the laminated unit are: 1) the laminated unit could have been deposited during the drainage event, or 2) the contact at the base of the laminated unit is the onset of the drainage event and the laminated unit itself is the redistribution of sediment during drainage through post-drainage. The first hypothesis seems less likely because there is bioturbation in the top laminated unit. This is suggestive of slower sedimentation with less turbid water which would enable the biota to take hold. The second hypothesis fits the current data better. Perhaps the laminated unit is a more gradual re-working. As water level fell, the sediments could be re-worked by the wave base in addition to shore processes. Loess deposition might also play a role in sedimentation. This is consistent with the increase in the silt size fraction seen in the grain size data. Eventually, water depths and turbidity would decrease as the landscape stabilized and bioturbation would begin,

39 resulting in the observed mottling seen towards the top of the laminated unit. Again, this evidence is supportive of a reworking and distribution of sediment that more closely resembles the second hypothesis.

Discussion

The purpose of this study is to evaluate the sedimentary record of Lake Ojibway in an attempt to reconstruct its drainage history. Toward that end, this paper presents the first examination of the lacustrine record using lake cores. The changes in stratigraphy show two distinct patterns (Fig. 5) which at first seem to coincide only with the Cochrane re-advance. However, there are two other factors that should be considered. Spatially, there is a change in the paleo water depth and in the bathymetric pattern of the basin in about same place as the Cochrane re-advance limit. All three likely influenced the sedimentation but we would still expect traceable stratigraphic patterns cross the lake basin as long as lake Ojibway was still a continuous connected body water.

Stratigraphy leading up to the Cochrane re-advance

Reid Lake’s varve record thins and thickens, and then the varves are disturbed above (Appendix

Reid lake core RD08-1C-7L-1). This stratigraphic signature may correspond to the Cochrane re- advance. One interpretation is the thin varves are the ice distal record and then thicken as the

Cochrane re-advances to an ice proximal position where sediment supply is higher. This site is outside the re-advance limit and was not over run but the ice proximal record is disturbed.

Stratigraphy above the Cochrane up to drainage

40 Stage 3 Stage 2 Stage 1 James Bay James Bay James Bay A A North lower elevation North A Margin position

Ice margin re-advanve Margin position Ice proximal Margin position supply sediment Ice proximal Diamict 41 Ice margin

Ice margin Ice proximal IRD Conceptual model Ice proximal Varves Ice proximal varves Ice proximal Ice proximal Varves A’ A’ A’ South higherelevation South Water level Margin position

Ice distal slow reworking sedimentation

Laminated re-worked Ice proximal varves Varves Ice proximal Ice margin Ice Stage 4 Pellet unit slow sedimentatioin ice distal Varves James Bay Ice proximal varves Diamict Ice proximal A A’

Margin position

local drainage landscape stabilization

Organic Lacustrine Laminated re-worked Ice proximal varves Reworking Varves

Ice margin Ice Ice proximal

Stage 5 Laminated re-worked Pellet unit slow sedimentatioin ice distal Varves Diamict James Bay Ice proximal A A’

Final drainage Organic Lacustrine Laminated re-worked Ice proximal varves Varves Ice proximal Organic Lacustrine Laminated re-worked Pellet unit slow sedimentatioin ice distal Stage 6 James Bay Varves Ice proximal varves Diamict A Ice proximal varves A’

42 Fig. 19 A conceptual model for lake drainage: Stage 1. Ice is proximal to a basin resulting in sedimentation that is coarse and poorly sorted. There is calving at the glacial margin resulting in IRD. Stage 2, the Ice margin retreats the sedimentation becomes better sorted and varves develop in the distal basin. In the newly exposed basin, there is ice proximal sedimentation like stage 2. In stage 3, the ice sheet re-advances over the basin deposition a diamict (perhaps the Cochrane till). The distal basin is experiencing thicker ice proximal varve deposition because the ice margin, the sediment source, is closer. There is still IRD from the calving ice margin. In stage 4, the ice has retreated, at some point lake drainage has initiated causing lake level to fall. The distal basin that is at higher elevation experiences the water level drop ﬁrst. The varve sediments may be reworked by the wave base and from shore processes as newly exposed sediment is eroded into the basin. The sedimentation rates decrease and organisms begin to take hold (bioturbating the upper section of the laminated unit). The IRD is curtailed in the higher elevations because the ice bergs can no longer be transported. In the deeper, proximal part of the basin there is low sedimentation and IRD (the pellet unit). In stage 5, the lake level continues to drop exposing the higher elevation basin, it experiences a local drainage. The lower elevation basin experiences lake level lowering and reworking takes place (similar to the upper basin in stage 4). The IRD deposition is halted, the lower lake level prevents transport of ice bergs. Finally, in stage 6, the lake has completely drained and landscape stabilization takes place. Sedimentation is reduced and organic deposition begins.

43 The stratigraphy above the Cochrane re-advance sediment is best exemplified at Lillabelle Lake.

Here there is a basal diamict that is likely the top of the Cochrane till. Above this, the contorted rhythmites are interpreted as an ice proximal signature post-Cochrane re-advance. After this, sedimentation is organized with more sorting between the silts and clays and varves develop.

The 26 varves decrease in thickness with constant deposition into the pellet unit (Fig. 15). When time is extrapolated from the sedimentation rate (2mm/yr) there are at least 200 years of deposition throughout the pellet unit. In total, at Lillabelle, there are 26 varve years and 200 years of deposition in the pellet unit. This is a minimum time frame of ~230 yrs between the

Cochrane retreat and the laminated unit above. The other lakes are farther north, more ice proximal, having shorter records with only a few varves before the pellet unit. As a result, the other records cannot be quantified in this way but likely represent shorter intervals of time. This sharp contact may represent higher ice retreat rates than seen at Lillabelle Lake. This could be due to a change in water level, possibly an increase, causing a rapid retreat.

Identification of drainage

The Ojibway lacustrine sedimentation regime is characterized by varves, rhythmites and IRD.

The units considered thus far in the discussion, varve and pellet units, have been consistent with

Lake Ojibway sedimentation. In all the lakes, atop either the slow sedimentation unit or the varves there is a laminated unit. When the sedimentation changes there is no longer IRD, and the clay content drops. There are no couplets only fine laminations dominated by silt. The stratigraphic changes in the laminated unit are a departure from the Ojibway lacustrine stratigraphy lower in the record. Above, the laminated unit, organic sedimentation is present indicating increased organic productivity and/or reduced clastic sedimentation. The stratigraphic evidence points to the base of the laminated as the start of drainage. The laminated unit above is

also associated with landscape re-stabilization either during drainage or afterwards. The question remains whether the stratigraphy is contemporaneous in time–one continuous drainage–or the stratigraphy is time transgressive–Ojibway lake level fell in steps, causing local depressions

(today’s modern lake basins) to experience local drainage at different times based on their elevation.

Drainage hypotheses

There are two tenable hypotheses for the drainage of Lake Ojibway. The first hypothesis is a continuous “rapid” drainage. If this were the case, we would expect a continuous drainage signature across the basin much like the laminated unit however, the sites to the north preserve an ice distal signature while the southern records are truncated. This in and of its self is not of great significance but there is also chronology. The chronology provides minimum ages near the top of the laminated unit. The ages are spread over several hundred years. This does not definitively exclude the first hypothesis but encourages the development of a second.

The second hypothesis is a slower step down drainage of Lake Ojibway. We would expect an unconformity in part of the basin as the water level fell and continued deposition in the deeper parts of the basin until final drainage. The stratigraphic patterns observed reflect this but there is not enough chronology at this time to determine the definitive age of the laminated unit.

The second hypothesis is favored because it fits the current stratigraphic record (Fig. 19). At the deeper sites interior to the Cochrane there is an ice distal signature followed by the drainage; whereas at the southern sites, the stratigraphy is truncated at the contact that represents the drainage and no ice distal record was recovered (Fig. 9). This is a function of the elevation in the

45 lake basin which controls when the local basins would experience drainage as the Ojibway water level fell. In this model the laminated unit I time transgressive and representative of landscape stabilization. There is some supporting evidence of the step down drainage. Shore lines have been mapped that are below the southern outlet of lake Ojibway indicating a lower lake level with in the basin (Veillette, 1994; Roy et al., 2008)

In both hypotheses a landscape stabilization unit would be expected after drainage. The nature of drainage could be better resolved with more stratigraphic and chronological control. Coring in the outlet channel may show a stratigraphic change that confirms or rejects one of the hypotheses, for example two drainage signatures would support the step down model. An additional coring transect in Quebec, across the Cochrane limit, would help to check the stratigraphic comparison and the possibility of finding a varve section that ties the pre and post

Cochrane re-advance varve records together.

The chronological control is coarse at this time but is could be improved with additional dates from more cores. This would make it possible to tell how long it took for the laminated unit to develop and if it is a transgression associated with drainage. Chronology in the varves, possibly with paleomag studies, may help in the chronological effort in establishing a maximum age before the drainage event.

Conclusions

The stratigraphy in the Ojibway basin is complicated. The transect approach employed in this study made it possible to see through the local effects and build a comparison from inside the

Cochrane limit southeast toward the distal basin. The finding of this study are:

1) The pellet unit is an Ojibway lacustrine slow sedimentation unit.

46 2) There is a minimum relative chronology, at Lillabelle Lake, of at least ~230 years between the

Cochrane re-advance and the final drainage event.

3) Lake drainage occurred at the base of the laminated unit. This is seen through the Ojibway basin on both sides of the Cochrane re-advance limit.

4) Further studies should continue to focus on chronology with emphasis on paleomag and 14C dating techniques to further constrain the time of the Lake Ojibway drainage. This will lend insight into deglacial history, and climate feed backs and triggering mechanisms.

47 Cited References

Alley, R. B. and A. M. Agustsdottir (2005). "The 8k event: Cause and consequences of a major Holocene abrupt climate change." Quaternary Science Reviews 24(10-11): 1123-1149. Andrews, J. T., B. Maclean, et al. (1996). "Final stages in the collapse of the Laurentide Ice Sheet, Hudson Strait, Canada, NWT: 14C AMS dates, seismic stratigraphy, and magnetic susceptibility logs." Quaternary Science Reviews 14(10): 983- 1004. Antevs, E. (1925). "Retreat of the last ice sheet in eastern Canada " Geological Survey of Canada, Memoir 146: 142 Antevs, E. (1928). "The last glaciation, with special reference to the ice retreat in northeastern North America." American Geological Society Research 17: 292. Barber, D. C. (1999). "Forcing of the cold event of 8,200 years ago by catastrophic drainage of Laurentide lakes." Nature 400: 344-348. Barber, D. C., A. Dyke, et al. (1999). "Forcing of the cold event of 8,200 years ago by catastrophic drainage of Laurentide lakes." Nature 400(6742): 344-348. Bauer, E., A. Ganopolski, et al. (2004). "Simulation of the cold climate event 8200 years ago by meltwater outburst from Lake Agassiz." Paleoceanography 19(3). Bell, R. (1879). Report on an exploration of the east coast of Hudson's Bay 1877. Montreal, Dawson. Bell, R. (1883). Reports on the geology of the basin of Moose River and of the Lake of the Woods and adjacent country, 1881. Montreal, Dawson. Bell, R. (1885). Observations on the geology, zoology and botany of Hudson's Strait and Bay made in 1885. Montreal, Dawson. Bell, R. (1892). The Laurentian and Huronian systems in the region north of Lake Huron. Toronto?, s.n.]. Breckenridge, A. (2007). "The Lake Superior varve stratigraphy and implications for eastern Lake Agassiz outflow from 10,700 to 8900 cal ybp (9.5-8.0 14C ka)." Palaeogeography, Palaeoclimatology, Palaeoecology 246(1): 45-61. Carlson, A. E., P. U. Clark, et al. (2007). "Geochemical proxies of North American freshwater routing during the Younger Dryas cold event." Proceedings of the National Academy of Sciences of the United States of America 104(16): 6556- 6561. Clark, P. U., S. J. Marshall, et al. (2001). "Freshwater forcing of abrupt climate change during the last glaciation." Science 293(5528): 283-287. Clark, P. U., N. G. Pisias, et al. (2002). "The role of the thermohaline circulation in abrupt climate change." Nature 415(6874): 863-869. Cofaigh, C. and J. A. Dowdeswell (2001). "Laminated sediments in glacimarine environments: Diagnostic criteria for their interpretation." Quaternary Science Reviews 20(13): 1411-1436. Coleman, A. P. (1909). Lake Ojibway: Last of the great glacial lakes. Ontario Bureau of Mines, Annual Report. 18: 284-293. Croudace, I. W., A. Rindby, et al. (2006). "ITRAX: description and evaluation of a new multi-function X-ray core scanner." Geological Society, London, Special Publications 267(1): 51-63. Dredge, L. A. and W. R. Cowan (1989). Quaternary Geology of Canada and Greenland, Nature Publishing Group: 214-235. Dredge, L. A. and W. R. Cowan (1989). Quaternary geology of the nortwestern canadian shield. quaternary geology of canada and greenland. R. J. Fulton, GSC. no. 1: 214-248.

48 Dyke, A. S. (2004). "An outline of North American deglaciation with emphasis on central and northern Canada." Quaternary Glaciations-Extent and Chronology, Part II(PART II): 373-424. Dyke, A. S. and L. A. Dredge (1989). Quaternary geology of the nortwestern canadian shield. quaternary geology of canada and greenland. R. J. Fulton, GSC. no. 1: 189-214. Ellison, C. R. W., M. R. Chapman, et al. (2006). "Surface and deep ocean interactions during the cold climate event 8200 years ago." Science 312(5782): 1929-1932. Ganopolski, A. and S. Rahmstorf (2001). "Rapid changes of glacial climate simulated in a coupled climate model." Nature 409(6817): 153-158. Hardy, L. (1976). Contribution à l'étude géomorphologique de la portion québécoise des basses terres de la baie de James. Montréal Université McGill. Thèse de doctorat. Hardy, L. (1977). "La déglaciation et les épisodes lacustre et marin sur le versan québécois des basses terres de la Baie de James." Geogr. Phys. Quat. 31: 261- 273. Hill, H. W., B. P. Flower, et al. (2006). "Laurentide ice sheet meltwater and abrupt climate change during the last glaciation." Paleoceanography 21(1). Hughes, O. L. (1959). Surficial geology of smooth rock and Iroquois Falls map areas, Cochrane district, Ontario. Jenkins, R. (1999). X-ray fluorescence spectrometry. 2nd Ed., Wiley: 232 pp. Lamoureux, S. (2001). Varve Chronology Techniques. Tracking Environmental Change Using Lake Sediments: 247-260. Leverington, D. W., J. D. Mann, et al. (2002). "Changes in the bathymetry and volume of glacial Lake Agassiz between 9200 and 7700 14C yr B.P." Quaternary Research 57(2): 244-252. Paulen, R. P. (2001). Quaternary Geology of the Timmins Area, Northeastern Ontario, University of Waterloo. Rahmstorf, S. (2002). "Ocean circulation and climate during the past 120,000 years." Nature 419(6903): 207-214. Rothwell, R. G. and F. R. Rack (2006). "New techniques in sediment core analysis: an introduction." Geological Society, London, Special Publications 267(1): 1-29. Roy, M., J. J. Veillette, et al. (2008). Deglaciation of the James Bay Lowlands and Northern Abitibi: Insights on Late-Glacial Ice Readvances and Drainage of Glacial Lake Ojibway. Eos Trans. AGU. San Francisco. 89(53): PP51A-1475. Schnurrenberger, D., J. Russell, et al. (2003). "Classification of lacustrine sediments based on sedimentary components." Journal of Paleolimnology 29(2): 141-154. Skinner, R. G. (1973). Quaternary stratigraphy of the Moose River Basin, Ontario. [Ottawa, Dept. of Energy, Mines, and Resources. Smol, J. P., Birks, H. John B., Last, William M., et.al. (2001). Tracking Environmental Change Using Lake Sediments, Springer Teller, J. T., D. W. Leverington, et al. (2002). "Freshwater outbursts to the oceans from glacial Lake Agassiz and their role in climate change during the last deglaciation." Quaternary Science Reviews 21(8-9): 879-887. Veillette, J. J. (1994). "Evolution and paleohydrology of glacial Lakes Barlow and Ojibway." Quaternary Science Reviews 13(9-10): 945-971. Veillette, J. J. (1994). "Evolution and paleohydrology of Glacial Lakes Barlow and Ojibway." Quat. Sci. Rev. 13: 945-971. Vincent, J. S. (1989). Quaternary geology of the nortwestern canadian shield. quaternary geology of canada and greenland. R. J. Fulton, GSC. no. 1: 249-275.

49 Appendix

The additional information in the Appendix is arranged by Lake. The general format for data were available are: 1) The lake name 2) Data table (lake name, LRC name, location in latitude longitude, modern elevation and water depth 3) A short description of the lake with colloquial description where needed 4) Google earth image of the lake with coring sites marked 6) Compiled core log with LRC data 7) Other data collected a) Grain size b) Chemistry c)X-ray radiograph d) Seismic

High resolution Images, raw instrumental data and initial core descriptions are available by request from:

Limnological Research Center University of Minnesota 500 Pillsbury Drive SE Room 672 Minneapolis, MN 55455 Phone: (612) 626 7889 Fax: (612) 626 7750

50 LRC: Naming convention

OJB2-SF07-1A-1L-1 Coring Site Hole at Site Tool used for drive Year Drive in Hole Expedition Section of Drive Section Lake

51 Core Thrust Inventory

52 Core Thrust Inventory Expedition Lake(fullname) LakeAbbr. Year SiteHole Core Type Section SectionID FieldID OJB FrederickHouseLake FH 2007 1A 1 L 1 OJBFH071A1L1 FH0711 OJB FrederickHouseLake FH 2007 1A 2 L 1 OJBFH071A2L1 FH0712 OJB FrederickHouseLake FH 2007 1A 3 L 1 OJBFH071A3L1 FH0713 OJB FrederickHouseLake FH 2007 1A 4 L 1 OJBFH071A4L1 FH0714 OJB FrederickHouseLake FH 2007 1A 5 L 1 OJBFH071A5L1 FH0715 OJB FrederickHouseLake FH 2007 1A 6 L 1 OJBFH071A6L1 FH0716 OJB FrederickHouseLake FH 2007 1A 7 L 1 OJBFH071A7L1 FH0717 OJB FrederickHouseLake FH 2007 1A 8 L 1 OJBFH071A8L1 FH0718 OJB FrederickHouseLake FH 2007 1A 9 L 1 OJBFH071A9L1 FH0719 OJB LillabelleLake LB 2007 1A 1 L 1 OJBLB071A1L1 LB0711 OJB LillabelleLake LB 2007 1A 2 L 1 OJBLB071A2L1 LB0712 OJB LillabelleLake LB 2007 1A 3 L 1 OJBLB071A3L1 LB0713 OJB LillabelleLake LB 2007 1A 4 L 1 OJBLB071A4L1 LB0714 OJB LillabelleLake LB 2007 1A 5 L 1 OJBLB071A5L1 LB0715 53 OJB LillabelleLake LB 2007 1A 6 L 1 OJBLB071A6L1 LB0716 OJB LillabelleLake LB 2007 1A 7 L 1 OJBLB071A7L1 LB0717 OJB LillabelleLake LB 2007 1A 8 L 1 OJBLB071A8L1 LB0718 OJB LillabelleLake LB 2007 1B 1 L 1 OJBLB071B1L1 LB0721 OJB LillabelleLake LB 2007 1B 2 L 1 OJBLB071B2L1 LB0721 OJB LillabelleLake LB 2007 1B 3 L 1 OJBLB071B3L1 LB0721 OJB LillabelleLake LB 2007 1B 4 L 1 OJBLB071B4L1 LB0721 OJB LillabelleLake LB 2007 1B 5 L 1 OJBLB071B5L1 LB0721 OJB LillabelleLake LB 2007 1B 6 L 1 OJBLB071B6L1 LB0721 OJB GardinerLake GA 2007 1A 1 B 1 OJBGA071A1B1 GA0711 OJB GardinerLake GA 2007 1A 2 B 1 OJBGA071A2B1 GA0712 OJB GardinerLake GA 2007 1A 3 B 1 OJBGA071A3B1 GA0713 OJB GardinerLake GA 2007 1A 4 B 1 OJBGA071A4B1 GA0714 OJB GardinerLake GA 2007 1A 5 B 1 OJBGA071A5B1 GA0715 OJB GardinerLake GA 2007 1B 1 B 1 OJBGA071B1B1 GA07021 OJB GardinerLake GA 2007 1B 2 B 1 OJBGA071B2B1 GA07022 OJB GardinerLake GA 2007 1B 3 B 1 OJBGA071B3B1 GA07023 OJB GardinerLake GA 2007 1B 4 B 1 OJBGA071B4B1 GA07024 OJB SouthFraserdale SF 2007 1A 1 L 1 OJBSF071A1L1 SF0711 Core Thrust Inventory Expedition Lake(fullname) LakeAbbr. Year SiteHole Core Type Section SectionID FieldID OJB FrederickHouseLake FH 2007 1A 1 L 1 OJBFH071A1L1 FH0711 OJB FrederickHouseLake FH 2007 1A 2 L 1 OJBFH071A2L1 FH0712 OJB FrederickHouseLake FH 2007 1A 3 L 1 OJBFH071A3L1 FH0713 OJB FrederickHouseLake FH 2007 1A 4 L 1 OJBFH071A4L1 FH0714 OJB FrederickHouseLake FH 2007 1A 5 L 1 OJBFH071A5L1 FH0715 OJB FrederickHouseLake FH 2007 1A 6 L 1 OJBFH071A6L1 FH0716 OJB FrederickHouseLake FH 2007 1A 7 L 1 OJBFH071A7L1 FH0717 OJB FrederickHouseLake FH 2007 1A 8 L 1 OJBFH071A8L1 FH0718 OJB FrederickHouseLake FH 2007 1A 9 L 1 OJBFH071A9L1 FH0719 OJB LillabelleLake LB 2007 1A 1 L 1 OJBLB071A1L1 LB0711 OJB LillabelleLake LB 2007 1A 2 L 1 OJBLB071A2L1 LB0712 OJB LillabelleLake LB 2007 1A 3 L 1 OJBLB071A3L1 LB0713 OJB LillabelleLake LB 2007 1A 4 L 1 OJBLB071A4L1 LB0714 OJB LillabelleLake LB 2007 1A 5 L 1 OJBLB071A5L1 LB0715 54 OJB LillabelleLake LB 2007 1A 6 L 1 OJBLB071A6L1 LB0716 OJB LillabelleLake LB 2007 1A 7 L 1 OJBLB071A7L1 LB0717 OJB LillabelleLake LB 2007 1A 8 L 1 OJBLB071A8L1 LB0718 OJB LillabelleLake LB 2007 1B 1 L 1 OJBLB071B1L1 LB0721 OJB LillabelleLake LB 2007 1B 2 L 1 OJBLB071B2L1 LB0721 OJB LillabelleLake LB 2007 1B 3 L 1 OJBLB071B3L1 LB0721 OJB LillabelleLake LB 2007 1B 4 L 1 OJBLB071B4L1 LB0721 OJB LillabelleLake LB 2007 1B 5 L 1 OJBLB071B5L1 LB0721 OJB LillabelleLake LB 2007 1B 6 L 1 OJBLB071B6L1 LB0721 OJB GardinerLake GA 2007 1A 1 B 1 OJBGA071A1B1 GA0711 OJB GardinerLake GA 2007 1A 2 B 1 OJBGA071A2B1 GA0712 OJB GardinerLake GA 2007 1A 3 B 1 OJBGA071A3B1 GA0713 OJB GardinerLake GA 2007 1A 4 B 1 OJBGA071A4B1 GA0714 OJB GardinerLake GA 2007 1A 5 B 1 OJBGA071A5B1 GA0715 OJB GardinerLake GA 2007 1B 1 B 1 OJBGA071B1B1 GA07021 OJB GardinerLake GA 2007 1B 2 B 1 OJBGA071B2B1 GA07022 OJB GardinerLake GA 2007 1B 3 B 1 OJBGA071B3B1 GA07023 OJB GardinerLake GA 2007 1B 4 B 1 OJBGA071B4B1 GA07024 OJB SouthFraserdale SF 2007 1A 1 L 1 OJBSF071A1L1 SF0711 Core Thrust Inventory Expedition Lake(fullname) LakeAbbr. Year SiteHole Core Type Section SectionID FieldID OJB SouthFraserdale SF 2007 1A 2 L 1 OJBSF071A2L1 SF0712 OJB SouthFraserdale SF 2007 1A 3 L 1 OJBSF071A3L1 SF0713 OJB SouthFraserdale SF 2007 1A 4 L 1 OJBSF071A4L1 SF0714 OJB SouthFraserdale SF 2007 1B 1 L 1 OJBSF071B1L1 SF0721 OJB SouthFraserdale SF 2007 1B 2 L 1 OJBSF071B2L1 SF0722 OJB SouthFraserdale SF 2007 1B 3 L 1 OJBSF071B3L1 SF0723 OJB SouthFraserdale SF 2007 1C 1 L 1 OJBSF071C1L1 SF0731 OJB SouthFraserdale SF 2007 1D 1 L 1 OJBSF071D1L1 SF0741 OJB SouthFraserdale SF 2007 1E 1 L 1 OJBSF071E1L1 SF0751 OJB SouthFraserdale SF 2007 1F 1 L 1 OJBSF071F1L1 SF0761 OJB SouthFraserdale SF 2007 1G 1 L 1 OJBSF071G1L1 SF0771 OJB SouthFraserdale SF 2007 1H 1 L 1 OJBSF071H1L1 SF0781 OJB 652KettleLake KET 2007 1A 1 L 1 OJBKET071A1L1 K0711 OJB 652KettleLake KET 2007 1A 2 L 1 OJBKET071A2L1 K0712 55 OJB 652KettleLake KET 2007 1A 3 L 1 OJBKET071A3L1 K0713 OJB 652KettleLake KET 2007 1A 4 L 1 OJBKET071A4L1 K0714 OJB 652KettleLake KET 2007 1A 5 L 1 OJBKET071A5L1 K0715 OJB 652KettleLake KET 2007 1A 6 L 1 OJBKET071A6L1 K0716 OJB 652KettleLake KET 2007 1B 1 L 1 OJBKET071B1L1 K0721 OJB2 ReidLake RD 2008 1A 1 L 1 OJB2RD081A1L1 RD081A1L OJB2 ReidLake RD 2008 1A 2 L 1 OJB2RD081A2L1 RD081A2L OJB2 ReidLake RD 2008 1A 3 L 1 OJB2RD081A3L1 RD081A3L OJB2 ReidLake RD 2008 1B 1 B 1 OJB2RD081B1B1 RD081B1B OJB2 ReidLake RD 2008 1B 2 B 1 OJB2RD081B2B1 RD081B2B OJB2 ReidLake RD 2008 1B 3 B 1 OJB2RD081B3B1 RD081B3B OJB2 ReidLake RD 2008 1C 1 L 1 OJB2RD081C1L1 RD081C1L OJB2 ReidLake RD 2008 1C 2 L 1 OJB2RD081C2L1 RD081C2L OJB2 ReidLake RD 2008 1C 3 L 1 OJB2RD081C3L1 RD081C3L OJB2 ReidLake RD 2008 1C 4 L 1 OJB2RD081C4L1 RD081C4L OJB2 ReidLake RD 2008 1C 5 L 1 OJB2RD081C5L1 RD081C5L OJB2 ReidLake RD 2008 1C 6 L 1 OJB2RD081C6L1 RD081C6L OJB2 ReidLake RD 2008 1C 7 L 1 OJB2RD081C7L1 RD081C7L OJB2 ReidLake RD 2008 1C 8 L 1 OJB2RD081C8L1 RD081C8L Core Thrust Inventory Expedition Lake(fullname) LakeAbbr. Year SiteHole Core Type Section SectionID FieldID OJB2 ReidLake RD 2008 1C 9 L 1 OJB2RD081C9L1 RD081C9L OJB2 ReidLake RD 2008 1D 1 L 1 OJB2RD081D1L1 RD081D1L OJB2 ReidLake RD 2008 1D 2 L 1 OJB2RD081D2L1 RD081D2L OJB2 ReidLake RD 2008 1D 3 L 1 OJB2RD081D3L1 RD081D3L OJB2 ReidLake RD 2008 1D 4 L 1 OJB2RD081D4L1 RD081D4L OJB2 ReidLake RD 2008 1D 5 L 1 OJB2RD081D5L1 RD081D5L OJB2 ReidLake RD 2008 1D 6 L 1 OJB2RD081D6L1 RD081D6L OJB2 ReidLake RD 2008 1D 7 L 1 OJB2RD081D7L1 RD081D7L OJB2 PetitdulacDufresnoy PD 2008 1A 1 L 1 OJB2PD081A1L1 PD081A1L OJB2 PetitdulacDufresnoy PD 2008 1A 2 L 1 OJB2PD081A2L1 PD081A2L OJB2 PetitdulacDufresnoy PD 2008 1A 3 L 1 OJB2PD081A3L1 PD081A3L OJB2 PetitdulacDufresnoy PD 2008 1A 4 L 1 OJB2PD081A4L1 PD081A4L OJB2 PetitdulacDufresnoy PD 2008 1A 5 L 1 OJB2PD081A5L1 PD081A5L OJB2 PetitdulacDufresnoy PD 2008 1A 6 L 1 OJB2PD081A6L1 PD081A6L 56 OJB2 PetitdulacDufresnoy PD 2008 1A 7 L 1 OJB2PD081A7L1 PD081A7L OJB2 PetitdulacDufresnoy PD 2008 1A 8 L 1 OJB2PD081A8L1 PD081A8L OJB2 PetitdulacDufresnoy PD 2008 1A 9 L 1 OJB2PD081A9L1 PD081A9L OJB2 PetitdulacDufresnoy PD 2008 1A 10 L 1 OJB2PD081A10L1 PD081A10L OJB2 PetitdulacDufresnoy PD 2008 1A 11 L 1 OJB2PD081A11L1 PD081A11L OJB2 PetitdulacDufresnoy PD 2008 1A 12 L 1 OJB2PD081A12L1 PD081A12L OJB2 PetitdulacDufresnoy PD 2008 1A 13 L 1 OJB2PD081A13L1 PD081A13L OJB2 PetitdulacDufresnoy PD 2008 1A 14 L 1 OJB2PD081A14L1 PD081A14L OJB2 PetitdulacDufresnoy PD 2008 1A 15 L 1 OJB2PD081A15L1 PD081A15L OJB2 PetitdulacDufresnoy PD 2008 1A 16 L 1 OJB2PD081A16L1 PD081A16L OJB2 PetitdulacDufresnoy PD 2008 1A 17 L 1 OJB2PD081A17L1 PD081A17L OJB2 PetitdulacDufresnoy PD 2008 1A 18 L 1 OJB2PD081A18L1 PD081A18L OJB2 PetitdulacDufresnoy PD 2008 1A 19 L 1 OJB2PD081A19L1 PD081A19L OJB2 PetitdulacDufresnoy PD 2008 1A 20 L 1 OJB2PD081A20L1 PD081A20L OJB2 PetitdulacDufresnoy PD 2008 1B 1 B 1 OJB2PD081B1B1 PD081B1B OJB2 PetitdulacDufresnoy PD 2008 1B 2 B 1 OJB2PD081B2B1 PD081B2B OJB2 PetitdulacDufresnoy PD 2008 1B 3 B 1 OJB2PD081B3B1 PD081B3B OJB2 PetitdulacDufresnoy PD 2008 1B 4 B 1 OJB2PD081B4B1 PD081B4B OJB2 PetitdulacDufresnoy PD 2008 1B 5 L 1 OJB2PD081B5L1 PD081B5L Core Thrust Inventory Expedition Lake(fullname) LakeAbbr. Year SiteHole Core Type Section SectionID FieldID OJB2 PetitdulacDufresnoy PD 2008 1B 6 L 1 OJB2PD081B6L1 PD081B6L OJB2 PetitdulacDufresnoy PD 2008 1B 7 L 1 OJB2PD081B7L1 PD081B7L OJB2 PetitdulacDufresnoy PD 2008 1B 8 L 1 OJB2PD081B8L1 PD081B8L OJB2 PetitdulacDufresnoy PD 2008 1B 9 L 1 OJB2PD081B9L1 PD081B9L OJB2 PetitdulacDufresnoy PD 2008 1B 10 L 1 OJB2PD081B10L1 PD081B10L OJB2 PetitdulacDufresnoy PD 2008 1B 11 L 1 OJB2PD081B11L1 PD081B11L OJB2 PetitdulacDufresnoy PD 2008 1B 12 L 1 OJB2PD081B12L1 PD081B12L OJB2 PetitdulacDufresnoy PD 2008 1B 13 L 1 OJB2PD081B13L1 PD081B13L OJB2 PetitdulacDufresnoy PD 2008 1B 14 L 1 OJB2PD081B14L1 PD081B14L OJB2 PetitdulacDufresnoy PD 2008 1B 15 L 1 OJB2PD081B15L1 PD081B15L OJB2 PetitdulacDufresnoy PD 2008 1B 16 L 1 OJB2PD081B16L1 PD081B16L OJB2 PetitdulacDufresnoy PD 2008 1C 1 B 1 OJB2PD081C1B1 PD081C1B OJB2 PetitdulacDufresnoy PD 2008 1C 2 L 1 OJB2PD081C2L1 PD081C2L OJB2 Rillinglake RI 2008 1A 1 L 1 OJB2RI081A1L1 RI081A1L OJB2 Rillinglake RI 2008 1A 2 L 1 OJB2RI081A2L1 RI081A2L OJB2 Rillinglake RI 2008 1A 3 L 1 OJB2RI081A3L1 RI081A3L OJB2 Rillinglake RI 2008 1A 4 L 1 OJB2RI081A4L1 RI081A4L 57 OJB2 Rillinglake RI 2008 1A 5 L 1 OJB2RI081A5L1 RI081A5L OJB2 Rillinglake RI 2008 1B 1 B 1 OJB2RI081B1B1 RI081B1B OJB2 Rillinglake RI 2008 1B 2 B 1 OJB2RI081B2B1 RI081B2B OJB2 Rillinglake RI 2008 1B 3 L 1 OJB2RI081B3L1 RI081B3L OJB2 Rillinglake RI 2008 1B 4 L 1 OJB2RI081B4L1 RI081B4L OJB2 Rillinglake RI 2008 1B 5 L 1 OJB2RI081B5L1 RI081B5L OJB2 Rillinglake RI 2008 1B 6 L 1 OJB2RI081B6L1 RI081B6L OJB2 Rillinglake RI 2008 1B 7 L 1 OJB2RI081B7L1 RI081B7L OJB2 Rillinglake RI 2008 1C 1 L 1 OJB2RI081C1L1 RI081C1L OJB2 Rillinglake RI 2008 1C 2 L 1 OJB2RI081C2L1 RI081C2L OJB2 Withington WI 2008 1A 1 L 1 OJB2WI081A1L1 WO081A1L OJB2 Withington WI 2008 1A 2 L 1 OJB2WI081A2L1 WO081A2L OJB2 Withington WI 2008 1A 3 L 1 OJB2WI081A3L1 WO081A3L OJB2 Withington WI 2008 1A 4 L 1 OJB2WI081A4L1 WO081A4L OJB2 Withington WI 2008 1A 5 L 1 OJB2WI081A5L1 WO081A5L OJB2 Withington WI 2008 1B 1 L 1 OJB2WI081B1L1 WO081B1L Core Thrust Inventory Expedition Lake(fullname) LakeAbbr. Year SiteHole Core Type Section SectionID FieldID OJB2 Withington WI 2008 1B 2 L 1 OJB2WI081B2L1 WO081B2L OJB2 Withington WI 2008 1B 3 L 1 OJB2WI081B3L1 WO081B3L OJB2 Withington WI 2008 1B 4 L 1 OJB2WI081B4L1 WO081B4L OJB2 Withington WI 2008 1B 5 L 1 OJB2WI081B5L1 WO081B5L OJB2 Withington WI 2008 1B 6 L 1 OJB2WI081B6L1 WO081B6L OJB2 Withington WI 2008 2A 1 L 1 OJB2WI082A1L1 WO082A1L OJB2 Barber'sBay BA 2008 1A 1 L 1 OJB2BA081A1L1 BB081A1L OJB2 Barber'sBay BA 2008 1A 2 L 1 OJB2BA081A2L1 BB081A2L OJB2 Barber'sBay BA 2008 1A 3 L 1 OJB2BA081A3L1 BB081A3L OJB2 Barber'sBay BA 2008 1A 4 L 1 OJB2BA081A4L1 BB081A4L OJB2 Barber'sBay BA 2008 1A 5 L 1 OJB2BA081A5L1 BB081A5L OJB2 Barber'sBay BA 2008 1A 6 L 1 OJB2BA081A6L1 BB081A6L 58 OJB2 Barber'sBay BA 2008 1A 7 L 1 OJB2BA081A7L1 BB081A7L OJB2 Barber'sBay BA 2008 1A 8 L 1 OJB2BA081A8L1 BB081A8L OJB2 Barber'sBay BA 2008 1A 9 L 1 OJB2BA081A9L1 BB081A9L OJB2 Barber'sBay BA 2008 1A 10 L 1 OJB2BA081A10L1 BB081A10L OJB2 Barber'sBay BA 2008 1A 11 L 1 OJB2BA081A11L1 BB081A11L OJB2 Barber'sBay BA 2008 1A 12 L 1 OJB2BA081A12L1 BB081A12L OJB2 Barber'sBay BA 2008 1A 13 L 1 OJB2BA081A13L1 BB081A13L OJB2 Barber'sBay BA 2008 1A 14 L 1 OJB2BA081A14L1 BB081A14L OJB2 JosephLake JH 2008 1A 1 L 1 OJB2JH081A1L1 JO081A1L OJB2 JosephLake JH 2008 1A 2 L 1 OJB2JH081A2L1 JO081A2L OJB2 JosephLake JH 2008 1A 3 L 1 OJB2JH081A3L1 JO081A3L OJB2 JosephLake JH 2008 1B 1 L 1 OJB2JH081B1L1 JO081B1L OJB2 JosephLake JH 2008 1B 2 L 1 OJB2JH081B2L1 JO081B2L OJB2 JosephLake JH 2008 1B 3 L 1 OJB2JH081B3L1 JO081B3L OJB2 JosephLake JH 2008 1B 4 L 1 OJB2JH081B4L1 JO081B4L OJB2 JosephLake JH 2008 1C 1 L 1 OJB2JH081C1L1 JO081C1L Stratigraphic Column Key

Modern organic Lacustrine

Laminated organics

Sand

Mottled silt and clays

Laminated silt and clay

Pellets Clasts

Varves

Homogenous silts and clays

Ice proximal Varvesl

Glacial Ice proximal

Diamicton

59 South Fraserdale Lake

60 SouthFraserdaleLake

Modern Modern LRC elevation Water Lakename Name Latitude Longitude (m) depth(m) SouthFraserdale Lake SF07 49.77279 81.52352 227 1.4

SouthFraserdaleLakeinelongatedlake~0.66kmlongand~0.15Kmwide.Itisontheflankofanesker. Thislake’sprimarycorerecordcomesfromsiteAandBbutadditionalcoresweretakenintransect downthelongaxisofthelake.

61 62

Depth (m) 6 5 4 3 2 South FraserdaleSouth

1A-1L-1 A Core 1A-2L-1 1A-3L-1 1A-4L-1

1B-1L-1 B Core 1B-2L-1 1B-3L-1 C Core Susceptibility 4 08 2 160 120 80 40 0 -40 1D-1L-1 Magnetic (si) . . . . 2.5 2.0 1.5 1.0 0.5 (gm/cc) Density 42,300 37,700 10203040500 7,320 14 14 14 LOI C age C age C age % Organic % Organic size are present boundaries some pebblesmmto cm atlamina with somedistortion 2.1: Laminated darkgray siltandclay well sorted in regularly siltis repeating packages 2.1: Laminated gray siltandsandy matrix. with anincreasingly laminated matrix. belowThe grades contact gray clay withalaminated clay 3: siltandclay pelletswithadark few cm. laminations loosedefinition over a isgradationalThe contact asthe clay 4: laminated gray to gray-brown silty material. matrix there isdark greenish-black mottled appearance withinthe 4.1 :gray to gray-brown clay with silty the sandissharp silt below. aboveThe uppercontact fingering ofthesandabove andthe isjaggedwithinterbottom contact possibly organic fragments the sandwithdark 5.3: Gray tansilty sapropel. Laminationsare mm-scale 5.1: darkbrown blacklaminated change basedontextural boundary saprope5.1: Massive unit blocky Unit Description stones 2.1: Pebbles are drop beacuse there islittleclay possibably fastdepostion 2.1: Ice proximal Varves 3: Ice proximal Varves 4.1: Bioturbation 5.3: erosional contact maybe doto freezing? exture conditions blocky 5.1: Similarto modern Interpretation SF07-1A-2L -1

X-ray radiograph

63 SF07-1A-2L-1 Al Si P S Cl 0

40 Depth (cm) 60

100 300 500 2000 0 400 800 200 800 0 10000 2500 Counts Counts Counts Counts Counts Ar K Ca Ti V

40 Depth (cm) 60

400 800 1000 5000 0 30000 500 2000 0 50 150 Counts Counts Counts Counts Counts

64 SF07-1A-2L-1 Cr Mn Fe Co Ni 0

40 Depth (cm) 60

0 100 250 0 1000 50000 200000 0 1000 −1.0 0.0 1.0 Counts Counts Counts Counts Counts Cu Zn Se Br Rb 0

40 Depth (cm) 60

−1.0 0.0 1.0 0 2000 0 400 1000 0 400 1000 500 2000 Counts Counts Counts Counts Counts

65 SF07-1A-2L-1 Sr Zr Pb inc coh 0

40 Depth (cm) 60

2000 8000 0 2000 200 600 1000 40000 120000 10000 25000 Counts Counts Counts Counts Counts

66 Kettle Lake

KettleLake

Modern Modern LRC elevation Water Lakename Name Latitude Longitude (m) depth(m) KettleLake KET07 49.45742 80.43858 278 9.9

Kettlelakehassteepbanksandthecoringlocationisofinanarrowarmofthelake.Thelakesonthe imagearepartofaeskersmallcomplexthatrunsthroughthemiddletrendingformthenortheastthe southwest.

68 Kettle Lake

A Core 12 Unit Description Interpretation

5.1: Dark brown sapropel 5.1: Similar to

1A-1L-1 color difference alongmodern cracks from black-gray to conditions with rusty orange some oxidation 13 5.1: Dark brown laminated sapropel laminations are contorted more verticle than horozintal 1A-2L-1

5.1yellowish brown 14 sapropel less laminated than above

4..1: Laminated 1A-3L-1 14 4.1: Dark gray to light gray

) 11,550 C age rhythmically laminated unit changing m B Core (

clayey laminations depositional environment from th 15 towards the top alternate between organic and silt clastic to organic Depth (m) ep rich layers dominate D 1B-1L-1 1A-4L-1 2.1 Massive graybrown 2.1: Disturbed sandy clay rich silt with slumping? Turbid- some pebbles lamina- ite tions are Contorted 16

1: Grayish brown diamic 1: Ice proximal 1A-5L-1 containing with clasts up to 5cm. Pebbles have different lithologies 17 including limestone and granite.

1A-6L-1 1: Tan white finer grained sandy diamic

18 0 100 200 300 0.5 1.0 1.5 2.0 2.5 3.0 01020304050

Magnetic Density LOI % Organic Susceptibility (gm/cc) (si) % Organic

69 Ket07-1A-4L-1 Al Si P S Cl 0

Depth (cm) 60

80 0 200 0 600 1400 0 200 400 0 4000 0 200 400 Counts Counts Counts Counts Counts Ar K Ca Ti V

Depth (cm) 60

80 300 600 900 0 4000 0 100000 0 1500 3500 0 200 500 Counts Counts Counts Counts Counts

70 Ket07-1A-4L-1 Cr Mn Fe Ni Cu

Depth (cm) 60

80 0 200 500 0 10000 0e+00 4e+05 0 300 600 0 50 150 Counts Counts Counts Counts Counts Zn Se Br Rb Sr

Depth (cm) 60

80 0 400 800 0 200 500 04080 0 1000 0 6000 Counts Counts Counts Counts Counts

71 Ket07-1A-4L-1 Zr Pb inc coh 0

Depth (cm) 60

80 0 1500 500 1500 20000 50000 5000 15000 Counts Counts Counts Counts

72 KET07-1A-4L -1

X-ray radiograph

73 Gardiner Lake

74 GardinerLake

Modern Modern LRC elevation Water Lakename Name Latitude Longitude (m) depth(m) GardinerLake GA07 49.30083 81.03142 239 4.6736

GardinerLakehasanelevationof239m.Thereisanoutlettothenorthinletfromanotherlaketothe south.

75 GardinerLakeBathometry

76 Gardiner Lake 4

A Core

Unit Description Interpretation 5 B Core 5.1: Massive dark brown 5.1:Similar to modern sapropel conditions 1A-1B-1

5.1:Laminated dark gryish brown sapropel 6

1B-1B-1 5.1: Introduction of 5.1: Light brown gray organics, onset of massive banded sapropel biotur bation 1A-2B-1

4.1: mottled grayish 4.1: Laminated unit brown silty clay some post drainage or

1B-2B-1 green to black material lake level lowering

Depth (m) laminations develpole at

8 1A-3B-1 te base of the unit

3: Silt and clay pellets 3: Pellets are IRD laminated clay matrix. the pellets are throughout but there are zone of higher abundance 9 1B-3B-1 2.3: Contorted coarse, 2.3: Disturbed rhyth- sandy silt mites Cochrane influence ? 1A-4B-1 1: Gray diamic 10

2.1:poorly sorted dark 2.1: Drop stones gray silt clay and sand 1B -4B-1 with some pebbles

11 1A-5B-1

12 1.2 1.6 2.0 2.4 2.8 0 50 100 150 200 0 5 10 15 20 25 30

Magnetic Density LOI Susceptibility (gm/cc) % Organic (si) % Organic

77 GA07-1A-3B-1

X-ray radiograph

78 GA07-1A-3B-1 Al Si P S Cl 0 ) Depth (cm

150 50 200 350 600 1200 0 200 500 0 300 600 0 300 600 Counts Counts Counts Counts Counts

Ar K Ca Ti V 0 Depth (cm)

150

200 800 1400 2000 6000 2e+04 1e+05 1000 4000 0 150 300 Counts Counts Counts Counts Counts

79 GA07-1A-3B-1 Cr Mn Fe Ni Cu 0 Depth (cm)

150 0 200 500 0 2000 50000 250000 0 400 1000 0 300 600 Counts Counts Counts Counts Counts

Zn As Se Br Rb 0 Depth (cm)

150 0 500 1500 0 150 300 0 400 1000 04080 1000 3000 Counts Counts Counts Counts Counts

80 GA07-1A-3B-1 Sr Zr Pb inc coh 0 Depth (cm)

150 0 4000 0 2000 400 1000 50000 80000 12000 20000 Counts Counts Counts Counts Counts

81 GA07-1A-3B-1

X-ray radiograph

82 AGA07-1A-4B-1 Al Si P S Cl 0

80 Depth (cm)

140

0 150 300 200 800 1400 0 200 500 0 400 0 300 600 Counts Counts Counts Counts Counts

Ar K Ca Ti V 0

80 Depth (cm)

140

0 600 1200 0 4000 8000 0e+00 8e+04 0 2000 0 50 150 Counts Counts Counts Counts Counts

83 AGA07-1A-4B-1 Cr Mn Fe Ni Cu

80 Depth (cm)

140

0 200 500 0 1500 0 150000 02040 04080 Counts Counts Counts Counts Counts

Zn As Se Br Rb 0

80 Depth (cm)

140

0 300 600 0 200 400 0 300 600 0 40 100 500 2000 Counts Counts Counts Counts Counts

84 AGA07-1A-4B-1 Sr Zr Pb inc coh

) 40

80 Depth (cm

140

0 4000 8000 500 2000 200 800 1400 10000 60000 5000 20000 Counts Counts Counts Counts Counts

85 7.0 M si Pb Sr Rb Fe Ti Ca K Si 7.2

7.4

7.6

7.8 Laminated unit

86 8.0

Depth ( m ) Depth ( 8.2

GA07-1A-3B Pellet unit 8.4

8.6 Varve unit 8.8

9.0 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 SD Lillabelle Lake

87 LillabelleLake

Modern Modern LRC elevation Water Lakename Name Latitude Longitude (m) depth(m) LillabelleLake LB07 49.10213 81.02627 244 2.36

LillabelleLakeseveralinletsandpossiblytwooutlets.Thelakeelevationis244mandthereiseskerto thewest.Thereisalsosomebankerosionalongtheshorestothesouthwest.

88 LillabelleLakeBathometry

89 Lillabelle Lake 3 A Core 9,810 14C age Unit Description

B Core 5.1: Dark black brown sapropel

5.3: Light tan gray layers of sand 1A-1L-1 4 5.3: Laminated, light gray silty sand 1B-1L-1

4.1: Massive, grayish brown silty faint laminations (mostly silt)

1A-2L-1 9,740 are apparent towards 14 5 C age the base of unit 1B-2L-1 3: Pellets of silt to sand faintly 5 laminated matrix 1A-3L-1 2.2: Gray silt and dark gray 1B-3L-1 6 brown clay, thinning varves

1A-4L-1 2.1: Convoluted, laminated gray silt

Depth (m) and sandy silt

1B-4L-1 1: Dark gray diamic 7 1A-5L-1 1B-5L-1 8 1A-6L-1 1B-6L-1 9 1A-7L-1

10 1A-8L-1 -50 0 50 100 150 200 0.51.0 1.5 2.0 2.5 3.0 0 10 20 30 40 50 Magnetic Density LOI Susceptibility (gm/cc) % Organic (si) % Organic

90 LB07-1A-2L -1

X-ray radiograph

91 LB07-1A-2L-1 Al Si P S Cl

40 Depth (cm) 60

0 50 150 200 800 0 100 200 0 200 0 150 300 Counts Counts Counts Counts Counts Ar K Ca Ti V 0

40 Depth (cm) 60

200 800 0 4000 0 100000 0 2000 5000 0 40 100 Counts Counts Counts Counts Counts

92 LB07-1A-2L-1 Cr Mn Fe Co Ni

40 Depth (cm) Depth 60

0 1000 0 1000 2500 0 100000 0 1000 2500 −1.0 0.0 1.0 Counts Counts Counts Counts Counts Cu Zn Se Br Rb

40 Depth (cm) 60

−1.0 0.0 1.0 0 200 400 0 200 500 04080 500 2000 Counts Counts Counts Counts Counts

93 LB07-1A-2L-1 Sr Zr Pb inc coh 0

40 Depth (cm) 60

5000 20000 0 1500 200 500 800 30000 45000 10000 18000 Counts Counts Counts Counts Counts

94 LB07-1B-2L -1

X-ray radiograph

95 LB07-1A-3L-1 Al Si P S Cl 0

40 Depth (cm) 80

0 150 300 600 1200 0 200 400 0 300 600 0 400 Counts Counts Counts Counts Counts

Ar K Ca Ti V 0

40 Depth (cm) 80

0 600 4000 7000 2e+04 8e+04 2000 5000 0 200 400 Counts Counts Counts Counts Counts

96 LB07-1A-3L-1 Cr Mn Fe Co Ni

40 Depth (cm) 80

0 200 500 1000 2500 50000 200000 1000 3000 −1.0 0.0 1.0 Counts Counts Counts Counts Counts

Cu Zn Se Br Rb 0

40 Depth (cm) 80

−1.0 0.0 1.0 0 200 500 0 200 500 −1.0 0.0 1.0 1500 3000 Counts Counts Counts Counts Counts

97 LB07-1A-3L-1 Sr Zr Pb inc coh 0

40 Depth (cm) 80

4500 6000 1000 2500 200 500 800 38000 44000 17000 20000 Counts Counts Counts Counts Counts

98 M si Pb Sr Rb Fe Ti Ca K Si 3.8

4.0

4.2

4.4 Laminated unit

4.6 LB07-1A-2L

4.8 Pellet unit 99

Depth ( m ) Depth ( 5.0

5.2

5.4 Varve unit

5.6

5.8 LB07-1A-3L -4 -2 0 2 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 -4 -2 0 2 4 SD Withington Lake

100

WithingtonLake

Modern Modern LRC elevation Water Lakename Name Latitude Longitude (m) depth(m) WithingtonLake WO08 48.9376 80.64532 293 3.35

WithingtonLakeis1.6kmlongformnorthtosouthand1.3kmwideeasttowest.Thelakeisshallowfor it’swith~3.3matthecoringsite,broadandflatbottomed.Thelakesurfaceisatelevationof293m.It sitsinasmallsaddleonatopographichigh.Thetopographyishighertothesouthandnorthat300m. Thelandtotheeastandwestishigherthanlake,levelbyseveralmeters,formingthelakebanksand thendiminishesinelevationtothecatchment.

101 WithingtonLakeBathometry

102 3.0

2.5

2.0

1.5

1.0

0.5 4

2 103

-2

-4 B Core s A Core Withington Lake Withington

2.00 2.25 2.50 2.75 3.00 3.25 3.50 3.75 4.00 4.25 4.50 4.75 5.00 5.25 5.50 5.75 6.00 6.25 6.50 6.75 7.00 7.25 7.50 7.75 8.00 8.25 8.50 8.75 9.00 9.25 Joseph Lake

104

JosephLake

Modern Modern LRC elevation Water Lakename Name Latitude Longitude (m) depth(m) JosephLake JO08 48.91899 80.84835 270 6.71

JosephLakeispartofachainoflakesthattrendNorthwesttoSoutheast.Onthelongaxisitis310m long.Thesurroundingtopographyisgenerallyflatlayingatanelevationof270m.Tothewest, swamplandsarepresentwithanapproximateelevationof269m.ThislakeisinterpretedtobeaSmall kettleinflatlayingterrainmuchofthesurroundinglandismarshy.

105 Joseph Lake Unit Description A Core 12 5.1: Massive dark brown 7810 14C age sapropel 1A-1L-1 5.1:Laminated dark gryish

13 brown sapropel

B Core 4.1:Mottled grayish brown silty clay. laminations develop at the contact where silty clay and 1A-2L-1

1B-1L-1 organic material interlayer 14 2.4: Massive dark gray silt and clay

2.2 : Contorted clay and

1A-3L-1 silt laminations Depth (m) C Core 15 1B-2L-1

1C-1L-1 2.1:poorly organized disturbed sandy silty 16 rhythmites pellets of silt,

1B-3L-1 sand and Clay through out

17 1B-4L-1

18 -20 0.5 1.0 1.5 2.0 2.5 0 20 40 60 80

Magnetic Density Susceptibility (gm/cc) (si)

106 Grain size JH 1B1L 0

40 Depth (cm) Depth (cm) 50

10 70

80 0.1 1 10 100 1000 Grain size (um)

107 Rilling Lake

108

RillingPond

Modern Modern LRC elevation Water Lakename Name Latitude Longitude (m) depth(m) RillingLake RI08 48.65384 80.59765 264 15.24

RillingPondislong(~500m)andnarrow(~150m)withawaterdepthof~15metersatthecoringsite. Thislakeissteepsided,thelakehassteepsides.Thereare3differentdepressionsinthebasin.The lakessurfaceelevationis264m.Thelandsurfacesurroundingthelake,hasgraterrelieftothewest.The lakeisspringfedanddoesnothaveanydirecttributariesandthereisanoutlettothenorth.

109 Rilling Pond

15 B Core s Unit Description

5.1: discontinuously lami-

1B-1B-1 nates dark brown sapropel 16

A Core 1 1B-2B-1 17 C Core 1A-1L-1

7610 14C age

1C-1L-1 6910 14C age 18 1B-3L-1 5.1: Laminated dark gryish 2 brown sapropel laminations

1A-2L-1 are uniform Depth (m) 3 4: Uniform finely laminated

19 1C-2L-1 gray clay silty which alter-

1B-4L-1 nates with darker gray silty clay. laminations are convo- lutes twards the bottom 1A-3L-1

20 1B-5L-1 1A-4L-1 4 2.3: thickly laminated silt and clay packages are some what irregular 21 1B-6L-1 1A-5L-1

22 1B-7L-1

23 -10 0 10 20 30 40 50 60 0.0 0.5 1.0 1.5 2.0 2.5 Magnetic Density Susceptibility (gm/cc) (si)

110 Frederick House Lake

111 FredrickHouseLake

Modern Modern LRC elevation Water Lakename Name Latitude Longitude (m) depth(m) FrederickHouseLake FH07 48.65039 80.88366 272 1.27

FredrickHousewasdammedwhichcausedthelaketoexpand,raisinginlakelevel.Webelievethereis littletonoHoloceneinthisrecord.Thereishigherosionalongthebanksofthislakelikelyresulting fromthedamming.ThissitewasincludedbecausesomeoftheearlyAntevs’sectionsarealongthelake shore.

112 FredrickHouseLakeBathometry

113 3.0

2.5

2.0

1.5 Density (gm/cc) 1.0

0.5 140 120 100 114 80 60

40 (si) Magnetic

20 Susceptibility 0

-20

1A-9L-1

1A-8L-1

1A-7L-1

1A-6L-1

1A-5L-1

1A-4L-1

1A-3L-1

Fredrick House Lake House Fredrick 1A-2L-1

A Core 1A-1L-1 1 2 3 4 5 6 7 8 9 10 11 Barber’s Bay

115 Barber’sBay

Modern Modern LRC elevation Water Lakename Name Latitude Longitude (m) depth(m) Barber'sBay BB08 48.61496 80.90916 279 14.63

Barber’sBayisadjacenttoFrederickHouseLakethebasinwaspartiallysurroundedbybluffstothewest thathadexposedbedrock.Thebankswereactivelyeroding.Thisbasinwas14.6mdeepatthecoring location.ThenorthtipofthebayiscutofffromFrederickHouseLakebyroadandRailfill.

116 Barber’sBayBathometry

117 Barber’s Bay

16 Magnetic Density Susceptibility (gm/cc) (si)

118 Barber’s bay continued

119 1.6 1.5 1.4 1.3 1.2 1.1 (gm/cc) 1.0 Density 0.9 0.8 18 16 (si) 120

14 Magnetic Susceptibility 12 10 8 6 Barber’s bay continued bay Barber’s 31 30 29 28 27 26 25 Reid Lake

121 ReidLake,Ontario

Modern Modern LRC elevation Water Lakename Name Latitude Longitude (m) depth(m) ReidLake RD08 48.54214 80.79506 271 10.05

ReidLakeislocatedeastofTimmins,Ontario.ThelongaxisofthelakeNorthWesttosoutheastlakeis ~1.3km.Thewaterdepthis~10matthecoringlocationwithabathymetrythathas2subbasins.Ithas anoutletstreamthatdrainstotheeastatanelevationof~271mandlowlandsexistatthesame elevationtowardthesouthsouthwest.Itisassociatedwiththeedgeofanaskerandhasakettlelike bathymetrywithsmallbasinsatdifferentdepths.Thislakewasexpandedbydamningintheearlypart ofthe20thcentury.Theoriginallakesedimentswerepreservedinthedeeperpartofthebasin.This lakewaschosenbecauseitisclosetobutoutsideoftheCochranelimitandbecausewebelievedthe therewouldbesufficientwaterdeathstopreserveanuninterruptedrecordandincreasethechanceof varveformation.

122 ReidLake,Bathometry

123 10 Reid Lake

11 1B-1B-1

Unit Description Interpretation

12 5.1: Dark brown sapropel 5.1: Similar to modern conditions 1B-2B-1 5.2 : Dark gryish brown 5.2: Landscape

1A-1L-1 silty peat stabilization 13 6950 14C age 1C-1L-1

1B-3B-1 5.1: Light brown gray massive 5.1: Introduction of to faintly laminated organics, bioturbation 14 1A-2L-1 sapropel 1D-1L-1 1C-2L-1 4.1: Dark gray to light gray 4.1: Laminated unit post rhythmically drainage or lake level 15 laminated clayey silt lowering 1C-3L-1 1D-2L-1 16 4.1: Dark gray calcareous 4.1: Disturbed rhythmites 1A-3L-1 quartzose clay, with Cochrane influence ? contorted laminations 1C-4L-1 Depth (m)

17 1D-3L-1

2.4: Convoluted, 2.4: Turbidite lamiated gray silt and sandy silt 18 1C-5L-1 1D-4L-1

2.3: Convoluted coarser, 2.3: Higher sedimentation sandy silt strat of Cochrane

19 1C-6L-1 re-advance? 1D-5L-1 2.2: Thinning varves 6.2: Ice sheet retreat

20 2.1: Gray clayey silt and 2.1: Ice proximal Varves

1C-7L-1 silt rhythmites. 1D-6L-1

21 2.1: Laminated graysilt 2.1: Ice proximal Varves and sandy silt 1C-8L-1

2.1: Darker fine grained 2.1: Ice proximal Varves 22 1D-7L-1 beds than unit 8 lami nated dark gray silty

1C-9L-1 clay and gray sandy silt 23 0 50 100150200 1.0 1.4 1.8 2.2

Magnetic Density Susceptibility (gm/cc) (si)

124 Reid Lake seismic proﬁle

3 5

Reid Lake coring site White corresponds to seismic 4

Transect 3

~6.2 m Vertical ~270 m Horizontal

125 Approximate coring site

Instrument re-scale arrows show corresponding reflector

13 126

19 The seismic proﬁle did not yield any visible stratigraphy at the location the corresponds to the coring site. The idealized 20 stratigraphic column is shown overlaying the nearest viable stratigraphy ~30-40m “north up proﬁle 2) distant from the 21

coring site. 22

23 Grain size RD 1C2L 0

40 Depth (cm) Depth (cm) 50

1 70 10

d10 d50 d90

80 0.1 1 10 100 1000 Grain size (um)

127 Petit Lac Dufresnoy

128

PetitduLacDufresnoy

Modern Modern LRC elevation Water Lakename Name Latitude Longitude (m) depth(m) Petitdulac Dufresnoy PD08 48.4342 78.97348 278 1.15

PetitduLacDufresnoyhasanelevationof273mandisbedrockcontrolledwithsomelow exposedbluffstothesouth.ThereisasmallbedrockIslandcentrallylocatedinthelake.Thislakehasan inletsourcedfromLacDufresnoyandoutletwhichdrainstothesouthSoutheast.Thislakewaschosen becauseofitslocationonthePaleoLakeReconstructionwhichputsitneartheOjibwayshorelineanda potentialoutletchannel.

129 Lac petite Dufresnoy

Unit Description

1B-1B-1 5.1: somewhat laminated to 3 mottles gray brown sapropel 1C-1B-1

4 1A-1L-1 1B-2B-1

5 1A-2L-1

5.1: mottled grayish brown

6 1B-3B-1 silty sapropel 1A-3L-1 1C-2L-1

7 1A-4L-1 1B-4B-1

4.1: mottled gray clay silty somewhat irregular laminations are throughout 8 1A-5L-1 1B-5L-1

14 9 7240 C age

1A-6L-1 4.1: Sediment is slightly darker in color than above

1B-6L-1 and the laminations become prominent with silt and clay 10

1A-7L-1 The contact is sharp and the record may be truncated. 1B-7L-1 2.2 rhythmically laminated gray clay and light gray silt. 11 These are interpreted to be varves 1A-8L-1

Uncoformity 2.4: massive brown gray

1B-8L-1 clayey silt

12 1A-9L-1 1B-9L-1

13 2.2 rhythmically laminated

1A-10L-1 gray clay and light gray silt. These varves thin up ward- sCouplets are clearly defined summer being

1B-10L-1 Uncoformity sandy silt and winter being dark gray clay

14 1A-11L-1

130 Petit Lac Dufresnoy continued

1A-7 The contact is sharp and the record may be truncated. 1B-7L-1 2.2 rhythmically laminated gray clay and light gray silt. 11 These are interpreted to be varves 1A-8L-1

Uncoformity 2.4: massive brown gray

1B-8L-1 clayey silt

12 1A-9L-1 1B-9L-1

13 2.2 rhythmically laminated

1A-10L-1 gray clay and light gray silt. These varves thin up ward- sCouplets are clearly defined summer being

1B-10L-1 Uncoformity sandy silt and winter being dark gray clay

14 1A-11L-1 1B-11L-1

1A-12L-1 7 1B-12L-1

16 1A-13L-1 1B-13L-1

17 1A-14L-1 1A-16L-1 1B-14L-1

18 1A-17L-1 1A-15L-1 1B-15L-1

19 1A-18L-1

20 1A-19L-1

21 1A-20L-1

22 0 100 200 300 0.8 1.2 1.6 2.0

131 5 4.5 4

3.5 Timiskaming E8 3 (Antevs, 1928) Timiskaming D8 2.5 (Antevs, 1926) 2 PD08-1A-8L 1.5 (This study) PD08-1B-7L 1 (This study) 0.5 Shallow River (Hughes, 1965 0 1450 1460 1470 1480 1490 1500 1510 1520 1530 1540 1550

132 Correlation of existing varve records the varves found in Lac petite Dufresnoy (correlation courtesy of Andy Breckenridge) PD A Core Varve Counts

1.9

1.8

1.7

1.6

1A-7L-1 1.5

1.4 Varve thicness (cm) Varve 1.3

1.2 0 20406080 Number of Varves

18 16 14 12 10 8 1A-8L-1 6 4 Varve thicness (cm) Varve 2 0

0 20406080 Number of Varves

2.0

1.8

1.6

1.4

1A-9L-1 1.2

1.0 Varve thicness (cm) Varve 0.8

0.6 0 20406080 Number of Varves

133 PD A Core Varve Counts

3.0

2.5

2.0

1.5 1A-10L-1

1.0 Varve thicness (cm) Varve 0.5

0.0 020406080 Number of Varves

4.5 4.0 3.5 3.0

1A-12L-1 2.5 2.0

Varve thicness (cm) Varve 1.5 1.0 0.5 020406080 Number of Varves

2.4 2.2 2.0 1.8 1.6 1.4 1.2 1A-13L-1 1.0 0.8 Varve thicness (cm) Varve 0.6 0.4 0.2 020406080 Number of Varves

134 PD A Core Varve Counts

3.0

2.5

2.0

1.5 1A-14L-1

1.0 Varve thicness (cm) Varve 0.5

0.0 020406080 Number of Varves

4.5 4.0 3.5 3.0

1A-15L-1 2.5 2.0

Varve thicness (cm) Varve 1.5 1.0 0.5 020406080 Number of Varves

2.4 2.2 2.0 1.8 1.6 1.4

1A-16L-1 1.2 1.0 0.8 Varve thicness (cm) Varve 0.6 0.4 0.2 020406080 Number of Varves

135 PD A Core Varve Counts

3.0

2.5

2.0

1.5 1A-14L-1

1.0 Varve thicness (cm) Varve 0.5

0.0 020406080 Number of Varves

4.5 4.0 3.5 3.0

1A-15L-1 2.5 2.0

Varve thicness (cm) Varve 1.5 1.0 0.5 020406080 Number of Varves

2.4 2.2 2.0 1.8 1.6 1.4

1A-16L-1 1.2 1.0 0.8 Varve thicness (cm) Varve 0.6 0.4 0.2 020406080 Number of Varves

136 PD A Core Varve Counts

3 1A-17L-1 2 Varve thicness (cm) Varve 1

0 0 20406080 Number of Varves

5.5 5.0 4.5 4.0 3.5 1A-18L-1 3.0

Varve thicness (cm) Varve 2.5 2.0 1.5 0 20406080 Number of Varves

1A-19L-1 3 Varve thicness (cm) Varve 2

1 0 20406080 Number of Varves

137 PD A Core Varve Counts

6.0

5.8

5.6 1A-20L-1 5.4 Varve thicness (cm) Varve 5.2

5.0 020406080 Number of Varves

138 PD B Core Varve Counts

0 Varve thicness (cm) Varve

0 20406080 Number of Varves

1 Varve thicness (cm) Varve

0 0 20406080 Number of Varves

1B-10L-110 1B-9L-1 1B-7L-1

Varve thicness (cm) Varve 0

0 20406080 Number of Varves

139 PD B Core Varve Counts

2.4 2.2 2.0 1.8 1.6 1.4 1.2 1B-11L-1 1.0 0.8

Varve thicness (cm) Varve 0.6 0.4 020406080 Number of Varves

2.4 2.2 2.0 1.8 1.6 1.4 1B-12L-1 1.2

Varve thicness (cm) Varve 1.0 0.8 020406080 Number of Varves

3.5

3.0

2.5

2.0

1B-13L-1 1.5

1.0 Varve thicness (cm) Varve

0.5 020406080 Number of Varves

140 PD B Core Varve Counts

3.5

3.0

2.5

2.0

1.5 1B-14L-1 1.0

0.5 Varve thicness (cm) Varve

0.0 0 20406080 Number of Varves

3.5

3.0

2.5

2.0 1B-15L-1

1.5 Varve thicness (cm) Varve

1.0 0 20406080 Number of Varves

141 Material Dated

142 143