THE POWER OF OUR IDEAS GEOLOGICAL SURVEY OF CANADA l\1EMOIR 430 SUBSURFACE GEOLOGY OF PRE-MESOZOIC STRATA, GREAT BEAR RIVER MAP AREA, DISTRICT OF MACKENZIE D.C. Pugh 1993 'f' Minister of Supply and Services Canada 1993 Avai lable in Canada through authorized bookstore agcnts and other bookstores or by mail from Canada Communication Group - Publishing Ottawa. Canada KI A OS9 and from Geological Survey of Canada otTiccs: 60 I Booth Street Ottawa. Canada KI A OE8 3303-33rd Street N.W .. Calgary. Alberta T2L :lA7 A deposit copy of this publication is also <wailahk for n:J'crcnce in public libraries across Canada Cat. No. M46-430E ISBN 0-660-14271\-3 Price suhject to change without notice Critical readers J.D. Ailken D./I", Morro\!' D.G. Cook 8.S XOIford N.J. :\lcillillan Scientific editor l\',C OllerenshalV Editor Jo MacGillivray Typesetting and layout Institute o/SedimelJ/Gly and Petroleum Geology Cartography unit Instilute o/Sedimentary and Petroleum Geology Author's address ]()7. 92./ - 7th Ave. SW Calgary. Alberta T2P IA./ Original manuscript received: 85-(}6- 1./ Final version approved/or publication: 87-()8-U PREFACE Over the last forty years much has been published on the sedimentary geology of Great Bear River area. The discoveries of oil in the Devonian reef at Norman Wells and in Cambrian sands at Tedji Lake have attested to the area's hydrocarbon potential. Surface mapping and local studies have revealed rock sequences and crustal structures of great potential value to our understanding of global geology. The aim of this report is to assist evaluation of the economic potential and to improve the interpretation of the geological history. The format follows that of the earlier report (Memoir 401) on the adjacent Peel River area. Based on subsurface data, the stratigraphy and structure of the area are analyzed in detail and are illustrated on a series of maps and cross-sections, and nomenclature is reviewed and integrated regionally with that of adjacent areas. Elkanah A. Babcock Assistant Deputy Minister Geological Survey of Canada PREFACE Au cours des quarante dernieres annees, la geologie sedimentaire de la zone de Great Bear River a fait l'objet de nombreuses publications. Les decouvertes de petrole faites dans le recif devonien a Norman Wells et dans les sables cambriens a Tedji Lake ont confirme le potentiel en hydrocarbures de cette zone. Des sequences rocheuses et des structures crustales d'une grande valeur pour la comprehension de la geologie globale ont ete revelees par des travaux de cartographie des formations en surface et des etudes geologiques locales. Le present rapport a pour objectif de faciliter l'evaluation du potentiel economique de cette zone et d'en ameliorer l'interpretation de l'histoire geologique. La presentation suit celle d'un rapport anterieur (memoire 401) portant sur la zone adjacente de Peel River. A partir de donnees souterraines, la stratigraphie et la structure de la zone sont analysees en detail, et illustrees sur une serie de cartes et de coupes, et la nomenclature est presentee et integree a celle des zones adjacentes de la region. Elkanah A. Babcock Sous-minitre adjoint Commission geologique du Canada CONTENTS I Abstract/Resume 2 Summary/Sommaire 4 Introduction 4 Study area 4 Previous work 4 Present st udy 4 AckIlowledgments 4 Borehole reference system 4 Mel rie conversion 5 Stratigraphy 5 Gelleral 5 Nomenclature 5 Preeambrian stratigraphy 5 Proterozoic 5 Unit I (Cap Mountain) 5 Shale unit ID Dolomite unit I1 Lower Paleozoic stratigraphy I1 Mount Clark Formation 12 Mount Cap formation 13 Member a 13 Member b 13 Member c J3 Member d 14 Member c 14 Member f 14 Member g 14 ~kmbIT h 14 Type area 14 Shale facies 15 Mahony Arch 15 Contacts 16 Saline River Formation 16 Lower clastic member 16 Sali member 17 Upper clast ic member 17 Ronning Group 17 Franklin Mountain Formation 18 Cyclic member 19 Rhythmic member 19 Cherty mem ber 20 Upper dolomite member 20 Type lithology 21 Mount Kindle Formation 21 Basal member 21 Lower dark member 21 Upper pale member 22 Undivided 22 Peel Formation 23 Middle Paleozoic stratigraphy 23 Delorme Group 24 Tsetso Formation 25 Tatsieta Formation 25 Arnica plat form 26 Fort Norman I'ormation 26 Arnica and Landry formations 28 Hume Formation 28 Headless Member 29 Middle member 29 Upper member 29 Undivided Hume Formation 29 Horn River Group 29 Hare Indian Formation 30 Bluefish Member 30 Grey shale member 31 Black shale member 31 Ramparts Formation 32 Canol Formation 32 Revision 33 Imperial Formation 33 Canyon Creek sandstone lentil 34 Jnngle Ridge hmestone member 34 Structural geology 34 Fon Norman structure 34 Mackenzie Arch 34 Bulmer Lake Arch 34 Mahonv Arch 34 Keelc Trough 34 Good Hope Basin 34 vlackenlie Plat form 34 Keele Arch 35 Great Bear Basin 35 Anderson Basin 35 Historical Geology 35 Earliest record 35 Cambrian-hypersaline basin 36 Late Cambrian to Late Ordovician 36 Late Ordovician to Late Silurian 36 Late Silurian to Early Devonian 36 Early 10 Middle Devonian 36 Givetian interlude 36 Late Devonian 37 Economic geolog, 37 Hydrocarbon potential 37 Cambrian clastics 37 Cambrian to Devonian carbonates 37 Mineral deposits 37 References 41 Appendix I Paleontologv 49 Appendix 2 Logs of \\'ells A-12 to P-78 121 Appendix 3 I ist of \\'ells "ith geological data 137 Appendix 4 Revision of Peel River area geological data Illustrations Figures (in pockets ri, 3-7], 18-131, 114-18/. 119, 201, 121. 221, 123. 241. [251. 1261. 1271, 1281. 1291> I. Location and index map 2. Diagrammatic, generalized time-litllOstratigraphic cross-sections in the Great Bear River area 3. Scenario of the Proterozoic subcrop and overlying Mount Clark Formation 4. Isopach and lithofacics map of Mount Cap Formation 5. Isopach, lithofacie' and Structure ContOur map of Saline River Formation 6. Isopach and struClUre contour map or Ronning Group 7. Isopach and lithofacics map of Frankhl1 ~'Iountain Formation 8. Isopach and lithofacies map of Mount Kindle and Peel formations 9. Isopach and structure contour map of the Devonian succession Delormc Group to Horn River Group 10. Isopach and lithofacies map of the Delorme Group, the Tsetso and Tatsieta formatiC'ns. and possible equivalents 11. Isopach and lithofacies map of Fon Norman Formation 12. Isopaeh and lithofacies map of Arnica and Landry formations 13. Isopach and lithofacies map of the Hume Formation 14. Isopach and lithofacies map of the Horn River Group and Ramparts Formation 15. Isopach and lithofacies map of the Bluefish \1ember 16. Isopach and lithofacies map of the Canol Formation 17. Isopacn and structure contour map of the Imperial Formation J8. Subcrop-outcrop map of pre-Mesozoic rocks 19. Pre-Ronning Group stratigraphic cross-section D-02 to G-22 20. Pre-Ronning Group stratigraphic cross-section H-34 to E-II 21. Ronning Group stratigraphic cross-section G-02 to G-60 22. Ronning Group srratigraphic cross-section N-39 to G-60 23. Ronning Group srratigraphic cro>s-section 1-01 to f-62 24. Devonian stratigraphic cross-section G-02 to G-52 25. Devonian stratigraphic cross-section K-29 to F-62 26. Devonian srratigraphic cross-section F-57m to K-7! 2-. Devonian srraligraphic cross-section J-65 to G_cO 28. Devonian srratigraphic cross-section I-70d 10 G-52 29. Upper Devonian stratigraphic cross-section G-12 to A-12 Table 6 I. Table of formations SUBSURFACE GEOLOGY OF PRE-MESOZOIC STRATA, GREAT BEAR RIVER MAP AREA, DISTRICT OF MACKENZIE Abstract The geological sequence in the subsurface of Great Bear River map area begins with the Proterozoic Hornby Bay Group on the east, separated by the Fort Norman structure from the Mackenzie Mountains Supergroup on the west. Overlying these unconformably are the Cambrian rocks of Good Hope Basin and Keele Trough, which straddle Mahony Arch and include three formations: the Mount Clark; the Mount Cap (Members a to h); and the Saline River (Lower clastic, Salt, and Upper clastic members). The Upper clastic strata grade into the lower Paleozoic carbonates of the Ronning Group, comprising three formations: the Franklin Mountain (Cyclic, Rhythmic, Cherty and Upper dolomite members); the Mount Kindle (Basal, Lower dark and Upper pale members); and the Peel (undivided). Pre-Devonian erosion exposed Cambrian rocks over Keele Arch. Above this regional unconformity lie, in the south, the Delorme Group comprising the Tsetso and Camsell formations, overlain by the Fort Norman Formation, which was deposited penecontemporaneously with the Tatsieta Formation to the northwest. Overlying these are the laterally equivalent Arnica (dolomite) and Landry (limestone) formations, superseded in turn by the Middle Devonian Hume Formation (Headless Member, Middle and Upper members) and the Givetian Horn River Group consisting of the Hare Indian Formation (Bluefish Member, Grey shale and Black shale members), the Ramparts Formation (Siltstone lentil, Platform and Reef members), and the Canol Formation (Allochthonous limestone). The Upper Devonian Imperial Formation, including the youngest rock unit below the sub-Mesozoic unconformity, contains the localized Canyon Creek sandstone and Jungle Creek limestone member. The economic prospects of the Great Bear River map area include widespread hydrocarbon potential and the possibility of zinc, lead, and uranium oxide deposits. La sequence geologique souterraine de la region cartographique de Great Bear Ri ver commence avec le groupe proterozoique de Hornby Bay a l'est, separe par la structure de Fort Norman du supergroupe de Mackenzie Mountains a l'ouest. Au-dessus reposent en discordance les roches cambriennes du bassin de Good Hope et la depression de Keele qui chevauche l'arche de Mahony et qui comprend trois formations: Mount Clark; Mount Cap (membres de a a h); et Saline River (membres inferieur clastique, salifere et superieur clastique).