An Update on the Investigation into the Stratigraphy of the Hudson Bay Area and Sedimentology of Local Coal Deposits

Jason Berenyi

Berenyi, J. (2010): An update on the investigation into the stratigraphy of the Hudson Bay area and sedimentology of local coal deposits; in Summary of Investigations 2010, Volume 2, Geological Survey, Sask. Ministry of Energy and Resources, Misc. Rep. 2010-4.2, Paper A-11, 9p.

Abstract In 2009 and 2010, Goldsource Mines Inc. (Goldsource) continued to utilize its proprietary geophysical interpretation methods to discover and delineate deposits on its Border coal project in the Hudson Bay area. The company has drilled over 140 holes on the property and has discovered 17 coal deposits, some with cumulative coal intersections up to 126.5 m in true thickness. In the summer of 2010, Ministry of Energy and Resources’ staff continued to study the depositional history of the strata hosting these coal discoveries. Over the past two summers, Ministry staff have logged a total of 103 drill holes, focussing attention around the largest discoveries and to areas with the greatest well control. The goal of the 2010 study was to acquire sufficient data to build a preliminary 3-D geological model of one or more of the coal deposits. Detailed core descriptions and geophysical well-log correlations provided the basis for the interpretations.

Keywords: Hudson Bay, Chemong, Pasquia, coal, sub-basin, karsting, subsidence, , Mannville, Cantuar, Success, , Dawson Bay, Red Beds, Ashern, Interlake.

1. Introduction This paper is an update of the work conducted in the Hudson Bay area in 2009 and 2010. For a more complete overview of the project please refer to Berenyi et al. (2009).

Between June and August 2010, Saskatchewan Ministry of Energy and Resources’ staff continued with the detailed core logging program initiated in the summer of 2009. Figure 1 illustrates drill-hole locations on the Border project and locations of coal discoveries as of September 2010.

The original focus of the program was to identify and correlate the regional stratigraphic units bounding the coal- bearing formation. In 2010, attention was focussed on areas that were delineated by the highest concentration of drill holes, in order to facilitate the development of a 3-D model. Lithologic core logging was conducted with the assistance of down-hole gamma and neutron geophysical logs.

The vast majority of coal intersected in the drill holes was sampled by the company for analytical testing prior to logging by Ministry staff. When minor amounts of centimetre-scale coal fragments were present, they were not logged in detail, as they were not known to be representative of the unit as a whole.

2. Update on Local Stratigraphy Each of the stratigraphic formations described by Berenyi et al. (2009) was encountered again in 2010, with much the same frequency. In addition to these units, a few deeper holes drilled in the winter of 2009/2010 intersected lower stratigraphic units of Devonian and strata (Figure 2). Descriptions of the Ashern Formation and Interlake Group are provided below. a) Interlake Group The Silurian Interlake Group is present in four holes with thicknesses in excess of 90 m. The relatively few occurrences of these units made formational correlations difficult. Based on regional correlations, the uppermost strata of the Interlake Group are interpreted as being part of the Cedar Lake Formation. The units are dominated by pale yellow-grey dolomitic framestones, primarily composed of Favosites corals and stromatoporoids, with lesser rugose corals and crinoids, all being infilled with a microcrystalline dolomite matrix. These rock types correspond

Saskatchewan Geological Survey 1 Summary of Investigations 2010, Volume 2

m E m E m E m E

m N m Niska 107

Niska 108

m N m

Pasquia 96

m N m Pasquia 97 Pasquia 98

Pasquia 05

Pasquia 02 m N m N m Chemong 03

Chemong 100 Chemong 06

Chemong 107 Chemong 20

m N m m N m

Split Leaf 39 m N m m N m Drill-hole Locations and Carbonaceous Interval Thickness

>0 to 5

m N m

m N m >5 to 10 Split Leaf 114 >10 to 25

Road km

m N m N m Leaf Lake

m E m E m E m E m E

Figure 1 - Base map showing the location of Goldsource drill holes. Red box on inset map outlines the study area. Sub-basins modelled in 2010 are circled in red.

Saskatchewan Geological Survey 2 Summary of Investigations 2010, Volume 2 very well with descriptions of the Cedar Lake WESTGATE Formation provided by Steam (1956), Jamieson (1979), VIKING / NEWCASTLE JOLI FOU and Jin et al. (1999). Below these units are very fine- SPINNEY HILL COLONY grained dolomitic strata that are finely laminated and PENSE McCLAREN WASECA SPARKY locally interbedded with argillaceous laminae and algal GENERAL PETROLEUMS

LOWER CANTUAR REX mats. These units may be correlative to the East Arm LLOYDMINSTER

MANNVILLE CUMMINGS 111 DINA Formation in (Steam, 1956), but too few

MESOZOIC APTIAN 122 BARREMIAN intersections were available for a definitive correlation. HAUTERIVIAN VALANGINIAN The Ashern Formation unconformably overlies the BERRIASIAN 142 SUCCESS S2 (INSINGER) TITHONIAN 150 Interlake Group. KIMMERIDGIAN 155

OXFORDIAN UPPER 157 b) Ashern Formation () CALLOVIAN 161 The lower Middle Devonian Ashern Formation is the BATHONIAN basal unit of the Elk Point Group (Baillie, 1951), and is

166

JURASSIC MIDDLE unconformably overlain by the Winnipegosis

BAJOCIAN JURASSIC 174 Formation. In the project area, the Ashern Formation AALENIAN 178 TOARCIAN was observed in the Niska 108, Pasquia 02, Pasquia 05 LOWER PLIENSBACHIAN SINEMURIAN JURASSIC HETTANGIAN 200 southwest, and the Chemong 06 areas, but was UPPER RHAETIAN NORIAN TRIASSIC CARNIAN 237 recognized in only five of the 103 holes logged, MIDDLE LADINIAN TRIASSIC ANISIAN 244 averaging approximately 9 m in thickness (Figure 1). It LOWER TRIASSIC SCYTHIAN 253 consists mainly of finely crystalline, non-fossiliferous, dolomitic mudstone with a minor and variable amount 300 of silt. The unit has a distinctive, dominantly pervasive, PENNSYLVANIAN pale orange-brown to deep orange-red colour. No 313 original depositional structures are visible, but the base of the Ashern Formation is commonly brecciated with CHESTERIAN abundant millimetre- to centimetre-scale angular 329 lithoclasts of dolomitic mudstone.

MERAMECIAN

334 3. Preliminary Modelling OSAGIAN

MISSISSIPPIAN 351

CARBONIFEROUS All images of sub-basins in this report were captured from 3-D models constructed in Paradigm™ GOCAD® KINDERHOOKIAN

360 2009.2. Four deposit areas (sub-basins) were modelled by extending surfaces through well markers at drill-hole

FAMENNIAN locations, which were derived from stratigraphic

373 correlations made by the author. All surfaces shown UPPER DEVONIAN represent the modelled base of the designated FRASNIAN formation (with the exception of the surface named

PALEOZOIC ‘carbonaceous top’). Poor recovery of the overlying 383 MANITOBA SOURISSOURIS RIVER RIVER GROUP 1ST RED BED formations, and extensive sampling of the coal by DAWSON BAY ND GIVETIAN 2 RED BED Goldsource, meant most carbonaceous contacts were DEVONIAN PRAIRIE MIDDLE ELK DEVONIAN EVAPORITE not present at the time of logging. As a result, 387 POINT GROUP WINNIPEGOSIS EIFELIAN carbonaceous intervals were modelled from data 394 ASHERN DALEJAN provided by Goldsource. ‘Carb top’ and ‘carb bottom’ LOWER EMSIAN 409 DEVONIAN PRAGIAN represent the start and end of any carbonaceous-bearing LOCHKOVIAN 418 UPPER SILURIAN LUDFORDIAN unit including all mineral partings. Since most holes GORSTIAN 424 SILURIAN HOMERIAN LOWER SHEINWOODIAN within these sub-basins were not drilled deep enough to TELYCHIAN INTERLAKE SILURIAN AERONIAN RHUDDANIAN 443 GAMACHIAN STONEWALL intersect underlying Devonian carbonates, the surfaces

RICHMONDIAN STONY MOUNTAIN for the Winnipegosis and Dawson Bay formations were 447 UPPER MAYSVILLIAN commonly projected directly below the deepest drill

ORDOVICIAN BIG HORN GROUP RED RIVER EDENIAN holes, and as such should be considered as minimum TRENTONIAN WINNIPEG

BLACKRIVERIAN 458 depths. The Ashern Formation and Interlake Group MIDDLE CHAZYAN were not included in preliminary modelling due to their

ORDOVICIAN LOWER ORDOVICIAN 489 limited occurrences. Orientation and horizontal scale of TREMPEALEAUAN UPPER FRANCONIAN DRESBACHIAN 501 DEADWOOD CAMBRIAN the deposits are indicated on each figure. Images of MIDDLE CAMBRIAN sub-basins are tilted toward the reader approximately PRECAMBRIAN + + + + + PRECAMBRIAN 45° from horizontal, and a three-times vertical Figure 2 - Stratigraphic correlation chart listing the units exaggeration has been applied, to better illustrate relief. encountered and their respective ages. Note: Prairie The black mesh lines show locations of control points Evaporite Formation is not present in project area. within the basins and serve to indicate changes in relief. Relief is also illustrated by shading produced by a eastward sun angle at 45° to the horizon.

Saskatchewan Geological Survey 3 Summary of Investigations 2010, Volume 2 The Pasquia 02 (PQ2) sub-basin model has the highest concentration of control points, incorporating 17 vertical holes and one deviated hole on the east side of the sub-basin, angled at -55°, and drilled due west underneath the deposit (Figure 3). The tight borehole spacing allows for several inferences to be drawn from the preliminary model. A minimum basin depth can be inferred from a hole, located in the center of the deposit, which was drilled to 200 m below surface and did not intersect the Devonian carbonate contact. For holes that did reach the Devonian carbonate, the Dawson Bay Formation was the first unit encountered, commonly followed by the Winnipegosis Formation. The Souris River Formation was not present in the project area. The PQ2 was the only area where the Success Formation was present in sufficient frequency to correlate throughout most parts of the deposit. The Cantuar Formation projection suggests a small ridge may be running from the northwest to the southeast across the centre of the PQ2 (Figure 3d). Thin, trace amounts of carbonaceous material were found on the peripheries of the PQ2, but were not included in the modelling. The thick carbonaceous intervals, shown in the model as infilling on the sub-Cantuar (SCU) surface, were confined within the perimeter of the PQ2. The Pense and Joli Fou formations are present across the entire region, but are thickest and deepest over the centre of the PQ2. The Viking and Westgate formations are less frequently encountered regionally, but also show a definite thickening and deepening over the centre of the deposit. These formations only occurred with enough frequency to be modelled in the PQ2 area. The Ashern Formation and Interlake Group were only encountered in the two holes on the far east side of the PQ2 and were not useful for correlation. The Pasquia 05 sub-basin (PQ5) covered a larger area than the PQ2, and its model utilizes stratigraphic formation markers from 18 holes (Figure 4). Initially identified as a single sub-basin, Goldsource has subsequently sub- divided the area into Pasquia 05 and Pasquia 05 southeast. The distinction between these two zones can be clearly seen in each of the modelled formations in Figure 4, but is most pronounced in the Cantuar Formation projection. Similar to PQ2, drill holes in the northwest and southeast portions of PQ5 haves minimum depths to the SCU of 200 m and 153 m respectively. Also similar to PQ2, the first carbonate unit below the SCU is the Dawson Bay Formation, typically followed by the Winnipegosis Formation. Preliminary modelling indicates that a potential ridge trending northeast to southwest separates the two sections of PQ5. Along the ridge, the Devonian carbonate surface is intersected at higher elevations, the Cantuar Formation is thinner, and the carbonaceous interval becomes negligible. Similar to PQ2, the overlying Pense and Joli Fou formations attain a maximum thickness and a maximum depth directly above the center of PQ5 and PQ5 southeast, respectively.

The Niska1 07 (NK7) and Niska1 08 (NK8) sub-basins are located approximately 13 km north-northeast of the Pasquia deposits and were delineated by 15 and 12 drill holes, respectively. The models for these deposits show a more dramatic relief profile than the PQ2 or PQ5 (Figures 5 and 6). Unlike the Pasquia area deposits, the SCU in the Niska sub-basins is best defined by the Winnipegosis Formation, as the Dawson Bay Formation is commonly absent. The NK7 and NK8 both have a minimum modelled depth of 200 m to the top of the SCU, and the thickest accumulations of carbonaceous materials are concentrated in the centre of each deposit. Unlike the southern areas where it is widespread, occurrence of the Cantuar Formation in the Niska area appears to be mainly restricted to the perimeter of the deposits. The overlying Pense and Joli Fou formations are more widespread than the Cantuar Formation, but less prevalent than in the more southerly regions. The Pense and Joli Fou formations continue to be thickest and deepest over the centre of the deposits.

4. Discussion The development of preliminary 3-D models for four of the largest discovered coal sub-basins in the Hudson Bay area has provided new perspectives on these unique deposits. The models clearly illustrate that the negative relief of the SCU provided the accommodation space for these coal deposits. Areas with the greatest accumulation of coal thicknesses can be directly correlated to the deepest parts of the sub-basins (distance from average surface elevation to deepest projected part of strata). The Pense, Joli Fou, Viking, and Westgate formations all appear to attain a maximum thickness and depth directly above the deepest portion of the sub-basin. This localized thickening of the formations is more pronounced in the Pense and Joli Fou formations and becomes successively less prominent in the Viking and Westgate formations. This may imply that syn- to post-depositional subsidence occurred for the formations overlying the coal; potentially related to coal compaction and maturation. The sheer depth, irregular morphology, and inconsistent orientation of these paleo-topographic lows indicate that they were unlikely to have formed by regional paleo-erosion alone. Intense fracturing and extensive brecciation are common within and proximal to most of these deposits. The next stage of the investigation will focus on whether these breccias were created by karst collapse, tectonic-induced fracturing or a combination of the two.

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a) Winnipegosis b) Dawson Bay c) Success d) Cantuar

e) carb bottom f) carb top g) Pense h) Joli Fou

Drill-hole location

Horizontal scale i) VikingI j) Westgate 0 0.5 1 2 km

Figure 3 - Stratigraphic model of the Pasquia 02 sub-basin (PQ2): a) Winnipegosis Formation; b) Dawson Bay Formation; c) Success Formation; d) Cantuar Formation; e) carb bottom; f) carb top; g) Pense Formation; h) Joli Fou Formation; i) ; and j) Westgate Formation.

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a) Winnipegosis b) Dawson Bay

c) Cantuar d) carb bottom

e) carb top f) Pense

Horizontal scale 0 0.5 1 2 km

g) Joli Fou Drill-hole location

Figure 4 - Stratigraphic model of the Pasquia 05 (PQ5) sub-basin: a) Winnipegosis Formation; b) Dawson Bay Formation; c) Cantuar Formation; d) carb bottom; e) carb top; f) Pense Formation; and g) Joli Fou Formation.

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a) Winnipegosis b) Cantuar

c) carb bottom d) carb top

e) Pense f) Joli Fou

Drill-hole location

Horizontal scale 0 0.5 1 2 km

Figure 5 - Stratigraphic model of the Niska 107 (NK7) sub-basin: a) Winnipegosis Formation; b) Cantuar Formation; c) carb bottom; d) carb top; e) Pense Formation; and f) Joli Fou Formation.

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a) Winnipegosis b) Cantuar

c) carb bottom d) carb top

e) Pense f) Joli Fou

Drill-hole location

Horizontal scale

0 0.5 1 2 km

Figure 6 - Stratigraphic model of the Niska 108 (NK8) sub-basin: a) Winnipegosis Formation; b) Cantuar Formation; c) carb bottom; d) carb top; e) Pense Formation; and f) Joli Fou Formation.

Saskatchewan Geological Survey 8 Summary of Investigations 2010, Volume 2 5. Acknowledgments The author would like to thank Goldsource Mines Inc. for its cooperation and collaboration with Ministry staff, and for providing unrestricted access to company drill cores and data. In addition, summer students Ron Leray and Luc Chabanole must be commended for their assistance, and Ministry geologists Arden Marsh and Sean Bosman for their assistance with well-log interpretation and GOCAD® modelling, respectively. Thanks as well to Arden Marsh and Ken Ashton for technical reviews and edits.

6. References Baillie, A.D. (1951): Silurian Geology of the Interlake Area, Manitoba; Manitoba Dept. Mines and Nat. Resour., Mines Branch, Pub. 50-1, 82p. Berenyi, J., Marsh, A., and Leray, R. (2009): Preliminary investigations of the Hudson Bay area coal deposits; in Summary of Investigations 2009, Volume 2, Saskatchewan Geological Survey, Sask. Ministry of Energy and Resources, Misc. Rep. 2009-4.2, Paper A-12, 14p, URL . Jamieson, E.R. (1979): Well Data and Lithologic Descriptions of the Interlake Group (Silurian) in Southern Saskatchewan; Sask. Dep t. Miner. Resour., Rep. 139, 67p.

Jin, J., Haidl, F.M., Bezys, R.K., and Gerla, G. (1999): The Early Silurian Virgiana brachiopod beds in the northeastern Williston Basin, Manitoba and Saskatchewan; in Summary of Investigations 1999, Volume 1, Saskatchewan Geological Survey, Sask. Energy and Mines, Misc. Rep. 99-4.1, p3-11.

Steam, C.W. (1956): Stratigraphy and Palaeontology of the Interlake Group and Stonewall Formation of Southern Manitoba; Geol. Surv. Can., Mem. 281, 162p.

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