ofm me 2005-111, geological map for part of nts 11e/07,

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HORTON GROUP WEST RIVER ST. MARYS FORMATION CROSS BROOK FORMATION* GRAHAM HILL, LOCHIEL*, BARRENS HILLS and LITTLE STEWIACKE RIVER FORMATIONS ( ( ( ( ( ( ( ( ( ( C h e d a b u c to F a u l t L@-E#Hwr L@-E#Hgh L@-E#Hbh/ls Picto u County Colchester Coun ty Pi c t o u Co u n t y G u y s b o r o u g h C o u n t y C ol c hes t er C ount y H al i f a x C ount y Gu ysbo u r gh C o un ty Halifax Co un ty 45 64 45 76 57 70 29 65 61 58 56 67 75 69 66 64 66 75 67 67 71 68 74 69 64 48 78 64 77 86 80 79 77 72 79 69 71 76 87 74 60 71 83 61 58 49 54 78 87 62 73 39 61 82 82 66 53 78 71 80 86 75 86 75 62 79 71 82 75 84 48 39 78 87 79 85 78 74 76 80 80 75 76 86 85 57 74 58 79 75 85 57 60 72 44 55 70 72 66 34 49 56 70 76 25 54 44 44 52 29 42 27 64 36 52 50 68 50 70 80 86 71 78 55 83 74 78 54 84 71 85 73 70 54 88 78 54 63 74 64 83 73 67 73 63 78 61 54 64 68 60 58 82 52 88 68 55 88 40 51 65 78 28 80 14 78 78 47 32 50 80 79 75 87 86 77 80 80 85 66 72 88 83 64 65 85 87 66 43 50 81 70 72 37 18 59 88 58 70 86 86 85 84 84 80 58 60 75 52 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200 1 5 0 200 200 150 200 200 100 200 1 150 5 0 20 0 0 200 200 1 5 0 20 0 1 5 0 2 00 20 0 0 200 200 2 0 0 150 200 150 150 200 200 1 0 0 200 100 2 00 150 T i m L a k e B e n L a k e M u d L a k e L o n g L a k e H o o d L a k e F i s h L a k e D r u g L a k e D e a n L a k e D u n n L a k e D u c k L a k e Per ch L ak e R o u n d L a k e E l b o w L a k e G r a n t L a k e P i p e r L a k e B l a c k L a k e M o o s e L a k e P e r c h L a k e R o o p s L a k e J e n n y L a k e L i t t l e L a k e C a l d e r L a k e F o r b e s L a k e S u c k e r L a k e L i t t l e L a k e B a r r e n L a k e D u n b a r L a k e N e l s o n L a k e H a t t i e L a k e P i c t o u L a k e G o r d o n L a k e D r y d e n L a k e D i c k e y L a k e S u c k e r L a k e S a m m y s L a k e M e a d o w L a k e I s l a n d L a k e A r c h i e s L a k e C a r i b o u L a k e M a c L e a n L a k e T h e M i l l p o n d R u s s e l l L a k e J o h n s o n L a k e M c I n t o s h L a k e M c K i n n o n L a k e G a i r l o c h L a k e L o n g J o h n L a k e S p e i c h t s L a k e s P o r c u p i n e L a k e C r a n b e r r y L a k e E a s t L o o n L a k e W e s t L o o n L a k e M a c D o n a l d L a k e C r a n b e r r y L a k e S o u t h L o o n L a k e B o t a n y B a y L a k e M a c P h e r s o n s L a k e W e s t B r a n c h L a k e E l l e n B r o w n L a k e N o r t h R i v e r L a k e Ott e r B r o o k L ak e B l a c k B r o o k L a k e B o t t l e B r o o k L a k e G r a n d f a t h e r s L a k e L i t t l e E l l e n B r o w n L a k e C a s t l e y P o o l s B e z a n s o n S t i l l w a t e r s B i l l W e i r S t i l l w a t e r s R h y n o s L a n d i n g S t i l l w a t e r Lime Brook Drug Brook Fall Brook Jack Brook B l ack Br ook B l a c k B r o o k Bla ck R iv er Otte r Bro ok Grants Brook G o rman Brook Holm e s B r ook Fu l t o n B ro o k Johnny Brook Glencoe Brook Crooked Brook Dog gett Brook Tanner y Bro o k Cameron Brook Gairloch Brook Maha i l as Br o ok W a te rval e B r oo k Millstream Brook East Bryden Brook Sam Cameron Br ook S crub G r ass Brook Bog Island Lake Bk Little Bra nch Co x Brook S o u t h B r o o k Ne ls o n River Meadow B rook Castley Brook Bentley Brook Ca l v a r y R i v er Blan chard Brook Archib ald Brook U pper B ryden Brook West River of Pictou BIG BROOK NORTH NELS ON RIV ER EAST RIVER OF P I CTOU WEST BRANCH EAST R IVER MIDDLE RIV E R OF PICTOU Moiche Hill Drug Brook Hill Kincaid Mountain Mount Thom Elgin Lorne Eureka Glencoe Rocklin Concord St Pauls Pembroke Burnside Sunnybrae Iron Rock Coromonie Trafalgar Marshdale New Lairg Lansdowne Eastville Watervale Brookville Millstream Centredale White Hill Springside Springville Graham Hill New Gairloch Gordon Summit Upper Burnside Websters Corner Lansberg Siding Campbells Siding Island East River Glengarry Station Lansdowne Station West River Station Hopewell Bridgeville 85 70 D u c k L a k e M a p l e L a k e C r a n e P o n d R o u n d L a k e B e a v e r L a k e S e m p l e L a k e M c Q u a r r i e L a k e B i g B r o o k L a k e L a n s d o w n e L a k e L i t t l e J o h n s o n L a k e Bea ver B k Su cke r Br o ok McDonald Brook M c Lellan s B rook Middle Bryden Br ook L i t t l e Bra nch Stewiac k e R i v er C o x B r o o k Maple Brook Bryden Brook Pembro ke River Sutherland Br oo k Big Branch Stewiacke River STEWIACKE RIVER W ES T R I V ER S T M AR Y S 5 00 000m E 5 00 000m E 01 01 02 02 03 03 04 04 05 05 06 06 07 07 08 08 09 09 5 10 5 10 11 11 12 12 13 13 14 14 15 15 16 16 17 17 18 18 19 19 5 20 5 20 21 21 22 22 23 23 24 24 25 25 26 26 27 27 28 28 29 29 5 30 5 30 31 31 32 32 33 33 34 34 35 35 36 36 37 37 38 38 5 39 000m E 5 39 000m E 50 11 000m N 50 11 000m N 12 12 13 13 14 14 15 15 16 16 17 17 18 18 19 19 50 20 50 20 21 21 22 22 23 23 24 24 25 25 26 26 27 27 28 28 29 29 50 30 50 30 31 31 32 32 33 33 34 34 35 35 36 36 37 37 50 38 000m N 50 38 000m N Jun 07, 2005 Descriptive Text 63°00' 45°15' 62°30' 45°15' 45°30' 63°00' 62°30' 45°30' B a y o f Fu n dy A t la nt i c O cea n Gulf of St. Lawrence New Brunswick P . E . I. Sable Island Nov a Sc otia 11F/05 11E/08 11E/07 11E/06 Regional Key Map Scale 1:50 000 1 0 1 2 3 km © Her Majesty the Queen in Right of the Province of Nova Scotia 2005 Halifax, Nova Scotia 62°45' 62°45' 45°22.5' 45°22.5' 100 0 100 km The St. Marys Basin, central mainland Nova Scotia, is dominated by a Late Devonian(?) - Early Carboniferous intracontinental alluvial fan-fluviatile-lacustrine basin-fill sequence that occupies the current boundary between the Meguma and Avalon terranes of the Canadian Appalachians. The Basin rocks belong to the Horton Group which is divided into six, partially laterally equivalent, formations. The stratigraphically lowest rocks are predominantly exposed in the central part of the Basin in a series of en echelon anticlinal closures (11E/06-08). These clastic rocks were deposited in a longitudinal drainage system represented by a lacustrine (Little Stewiacke River Formation) and an overlying braided fluvial (Barrens Hills, Lochiel and Graham Hill formations) environment, which are in turn overlain by the Cross Brook and West River St. Marys formations. These rocks unconformably overly the Meguma Group, reflecting a decrease in accommodation space and implying that the St. Marys Basin is underlain, at least in part, by Meguma basement. This map is predominantly underlain by the Little Stewiacke River and Barrens Hills formations. The contact between these formations is exposed on this map on the Stewiacke River about 100 m south of its intersection with highway 289. Facing directions in the vicinity of this contact clearly show that the Barrens Hills Formation overlies the Little Stewiacke River Formation. However, contact relationships between these formations are still being mapped out, so they are presented as an undivided unit on this map. The Little Stewiacke River Formation, which consists of interstratified, thinly bedded, bioturbated mudstone, fissile, light to dark grey and black shale and slate, and light to dark grey sandstone, frequently contains abundant comminuted plant debris. Coarsening- and thickening-upward cycles, 2-25 m thick, occur with individual beds ranging in thickness from 2 mm to 15 cm. In some localities the sandstones display soft sediment deformation. In many sections, the finer grained lithologies display a slaty cleavage. Siltstone/shale-sandstone contacts are either sharp or transitional, or, less commonly, erosional. Sandstones are typically grey or dark grey weathering, very fine- to fine-grained and micaceous, and in some locations, moderately feldspathic. Primary and penecontemporaneous sedimentary features include normal grading, parallel lamination, ripple crosslamination, loading features and bioturbation. Sandstone strata generally vary from millimetres to decimetres in thickness. As the contact with the overlying Barrens Hills Formation is approached, the upper member lithologies are coarser, erosionally amalgamated with channel scours and possible swaley cross-stratification, and display large scale (10-20 cm) trough cross-stratification. Fine, organic debris is often abundant in these sandstones and their weathering colour darkens accordingly. The Barrens Hills Formation is characterized by resistant intervals of light grey to grey-white weathering, fine- to very coarse-grained sandstone, monomict or polymict granulestone and conglomerate interstratified with recessive intervals of micaceous, grey to dark grey weathering shale and/or siltstone. Interbeds of minor red siltstone and sandstone also occur. The sandstones are dominated by quartz and feldspar, although grey sedimentary lithic clasts are common near the base of the Formation. Feldspars are generally intensely weathered to clay minerals. Locally, the sandstones may be slightly micaceous, moderately feldspathic, and contain varying, but significant amounts of dark grey sedimentary lithic clasts of schist and sandstone, some with a fabric, that are probably derived from the Meguma Terrane south of the St. Marys Basin. The Barrens Hills Formation underlies large areas of both the central and eastern Basin where it outcrops along a broad, regional, northeastward-trending anticlinal axis. To the west of the Stewiacke River region the Formation thins dramatically and passes into the laterally equivalent Graham Hill Formation. To the east of this map sheet, it passes into the laterally equivalent Lochiel Formation. The basal contact of the Barrens Hills Formation is positioned where sand- to granule-sized quartz-rich clastic sediment starts to predominate over the darker and more thinly bedded lithologies of the Little Stewiacke River Formation. This contact is exposed in the Stewiacke River region (11E/07) where it is transitional over 1 m. It is recognized by the abrupt occurrence of thin (10-20 cm) lenses of small pebble conglomerate at the base of the Barrens Hills Formation. In the western portion of the map, the Graham Hill Formation consists of 1220 m of red and maroon weathering, finer grained litharenite to feldspathic litharenite and siltstone with thick intervals of grey weathering, interstratified, coarser grained sandstone, pebbly sandstone and granule to pebble conglomerate. Clasts include quartz, mica, intraformational siltstone (0.5-1 cm), and flow-banded rhyolite. Regional relationships indicate that the Graham Hill Formation is also a lateral facies equivalent of the Barrens Hills Formation. In separate stratigraphic sections, both formations conformably overlie the Little Stewiacke River Formation. In the eastern portion of 11E/06, the Graham Hill Formation is complexly interstratified with both the Barrens Hills and Little Stewiacke River formations. This indicates that the three formations are, at least in part, time equivalents. This style of interfingering is thought to characterize the stratigraphic relationships between formations throughout the Basin. The Cross Brook Formation consists of grey-green weathering sandstone interstratified with less abundant grey-green weathering siltstone, shale and conglomerate and rare limestone. The Cross Brook Formation is not exposed in this map area, but further east it occurs along the southern flank of the Basin. The sandstones are typically fine- to coarse-grained, micaceous, variably feldspathic, and locally contain varying amounts of granule-sized quartz and sedimentary/metasedimentary lithic fragments. They generally are thinly bedded and commonly display ripple crosslamination, and trough cross-stratification in sets up to 1 m thick. Pebble conglomerates are polymict, poorly sorted and framework supported. Dominant clast types in the sandstones and conglomerates include psammite, pelite, micaceous granite, vein quartz and muscovite. Less abundant, sedimentary clasts include laminated carbonaceous mudstone (possibly of algal origin), siltstone, sandstone, carbonate and organic debris, all of which are interpreted as intrabasinal detritus. Most clasts are subangular to subrounded. Siltstone and shale beds are grey weathering, micaceous and display parallel lamination and ripple crosslamination. The West River St. Marys Formation consists of reddish-brown to grey-brown weathering conglomerate interstratified with grey-brown weathering sandstone. The Formation outcrops along the southern flank of the central and eastern portions of the Basin. The red-brown to grey-brown weathering conglomerate contains clasts ranging from pebbles to boulders. The rock is dominantly framework- to locally matrix- supported with a roughly 80:20 framework to matrix ratio. It is very poorly to poorly sorted, may contain imbricated pockets, or display crude inverse- to normal-grading. The conglomerate contains numerous, major scour surfaces and fines upward to large pebble-size in the top of the measured section. Basal contacts with sandstone lenses are erosional. Clast shape and size vary with composition. Sedimentary clasts are largest (sandstone to 90 cm, shale/siltstone to 6 cm) and are subrounded to subangular. Metasedimentary clasts are similar in shape, but generally smaller in size. Granite and quartz clasts are rounded to well-rounded, the latter reaching 30 cm in diameter. Sandstone clasts are dominantly grey-green weathering, fine- to medium-grained, micaceous and feldspathic. In some instances they exhibit postdepositional en echelon tension fractures. Clast counts also indicate that metasedimentary clasts are marginally more dominant in the west and sedimentary clasts are more dominant in the east. Metasedimentary clasts are dominantly dark grey weathering pelite, commonly with an inherited tectonic fabric. The matrix is grey-brown weathering, medium- to very coarse-grained, feldspathic, lithic sandstone. Conglomerates further upsection are finer grained and better organized, displaying imbrication and trough cross-stratification. In the eastern portion of the Basin, these conglomerates contain a significant amount of plant debris including fragments up to 30 cm long. Sandstone occurs as trough-shaped lenses up to approximately 2 m thick, characteristically 30-80 cm thick, with a minimum lateral extent of 15 m. The lenses are grey-green weathering, medium- to very coarse-grained, feldspathic and micaceous. Occasional interstratified pebbly or granulestone horizons occur. Scours, trough cross-stratification (sets to 30 cm), ripple cross-stratification and normal grading all occur in the sandstone. The number of sandstone lenses increases upsection. The deposition of coarse conglomerates occurs along the southern flank of the Basin suggesting a strong tectonic influence on sedimentation where subsidence along this Basin margin occurs along northerly dipping listric normal faults. In contrast, the character of the sediments does not vary with proximity to the northern margin (Chedabucto Fault) suggesting that the Fault does not constitute the J. B. Murphy and R. J. Rice Recommended Citation Map Notes Universal Transverse Mercator Projection (UTM), Zone 20, Central Meridian 63°00' West. Base and digital data derived from the Nova Scotia Topographic Database (NSTDB). The NSTDB is available from Service Nova Scotia and Municipal Relations (SNSMR), Land Information Services Division (LIS), Nova Scotia Geomatics Centre (NSGC), Amherst, Nova Scotia. We acknowledge the support of the Geological Survey of Canada, Natural Sciences and Engineering Research Council, Caledonia Mining Corporation and the Nova Scotia Department of Natural Resources. We are grateful to David Dowe, Samantha Evans, Lorne Jennex, Fraser Keppie, Jon Malone, Sarah Jane Mosher, Cashel Meagher, Alex Nazck, Jacquie Stevens, Tim Stokes and Tim Webster for assistance in the field. Map production funded by Natural Resources Canada and Nova Scotia Department of Natural Resources under the Targeted Geoscience Initiative (Phase 2) Project: Geological Mapping and Resource Evaluation in Central Nova Scotia, 2004-2005. Cartography and reproduction by Nova Scotia Department of Natural Resources, Geoscience Information Services Section, 2004-2005. North American Datum (NAD) 1927. Disclaimer The information on this map may have come from a variety of government and nongovernment sources. The Nova Scotia Department of Natural Resources does not assume any liability for errors that may occur. ± LEGEND CARBONIFEROUS LATE DEVONIAN - EARLY CARBONIFEROUS undivided reddish-brown to grey-brown weathering, pebble to boulder conglomerate interstratified with grey-brown weathering sandstone. Abundant clasts derived from the Meguma Terrane. grey-green weathering sandstone, interbedded grey-green weathering siltstone, shale, conglomerate and rare limestone. Abundant clasts derived from the Meguma Terrane. Map Area.................. NTS Map Sheets...... Study Area................ GRAHAM HILL FORMATION (L@-E#Hgh): red and maroon weathering, finer grained litharenite to feldspathic litharenite and siltstone with thick intervals of grey weathering, interstratified, coarser grained sandstone, pebbly sandstone and granule to pebble conglomerate. Clasts include quartz, mica, intraformational siltstone (0.5-1 cm), and flow-banded rhyolite. LOCHIEL FORMATION* (L@-E#Hl): grey or green, fine- to very coarse-grained, micaceous and feldspathic sandstones, interbedded minor granulestone, dark grey siltstone. E#W L@-E#Hcb L@-E#Hwr Nova Scotia Department of Natural Resources Mineral Resources Branch Murphy, J.B. and Rice, R.J. 2005: Geological map for part of NTS 11E/07, Hopewell area, Nova Scotia; Nova Scotia Department of Natural Resources, Mineral Resources Branch, Open File Map ME 2005-111, scale 1:50 000. original Basin margin, and that an unknown portion of the Basin and its Meguma basement have been tectonically removed and may be found north of the Fault. The St. Marys Basin is an example of basin development and evolution adjacent to an intracontinental fault zone associated with oblique convergence during orogenesis. Its evolution provides constraints on the potential relationship between the termination of the mid-Paleozoic Acadian Orogeny, subsequent basin development and the ongoing interactions between the Avalon and Meguma terranes, and between Laurentia and Gondwana during the assembly of Pangea. More generally, because the relationship between fabric development and motion along intracontinental strike-slip faults in continental zones is difficult to interpret, the sedimentology and structural geology in basins developed along these fault zones may preserve a less ambiguous record of the main tectonic events. The evolution of the St. Marys Basin preserves evidence of protracted dextral shear along an intracontinental fault zone during collisional orogenesis and the assembly of Pangea. The origin and evolution of the Basin are attributed to either discrete or progressive dextral strike-slip tectonics along the Minas Fault Zone (MFZ) between the Late Devonian and Late Carboniferous. Evidence for the Late Devonian origin of the Basin is recorded along its southern flank by the fabrics of the deformed ca. 370 Ma granites, the overall sedimentary facies distribution and some syndepositional features within the clastic rocks. The most intense deformation within the Basin is concentrated in a narrow east-northeastward-trending zone, in which predominantly fine grained clastic rocks are deformed into periclinal folds and related reverse faults. The orientation of this zone, relative to the MFZ, is consistent with dextral shear. At least some of this deformation occurred after the deposition of the overlying Viséan Windsor Group (11E/06). The style of deformation along the present northern margin of the Basin (the Chedabucto Fault) is also consistent with regional dextral shear. Benson, D.G. 1967: Geology of the Hopewell map area, Nova Scotia; Geological Survey of Canada, Memoir 343, 58 p. and Map 1215A, scale 1:63 360 Benson, D.G. 1974: Geology of the Antigonish Highlands, Nova Scotia; Geological Survey of Canada, Memoir 376, 92 p. Fletcher, H. and Faribault, E.R. 1887: Geological surveys and explorations in the counties of Guysborough, Antigonish, Pictou, Colchester and Halifax, Nova Scotia from 1882-1886; Geological Survey of Canada, Annual Report, v. II, 1886, pt. P, p. 5-128. Jennex, L.C. 1998: Geological and geophysical investigation of the western St. Mary's Basin, central mainland Nova Scotia: implications for paleoplacer gold potential; unpublished M.Sc. thesis, St. Francis Xavier University, Nova Scotia, 286 p. Jennex, L.C., Murphy, J.B. and Anderson, A.J. 2000: Post-orogenic exhumation of an auriferous terrane: the paleoplacer potential of the Early Carboniferous St. Marys Basin, Canadian Appalachians; Mineralium Deposita, v. 35, p. 776-790. Murphy, J.B. and Rice, R.J. 1998: Stratigraphy and depositional environment of Horton Group rocks in the St. Mary’s Basin, central mainland Nova Scotia; Atlantic Geology, v. 34, p. 1-26. Murphy, J.B., Rice, R.J., Stokes, T.R. and Keppie, D.F. 1995: The St. Mary's Basin, central mainland Nova Scotia: Late Paleozoic basin formation and deformation along the Avalon-Meguma terrane boundary, Canadian Appalachians; in New Perspectives in the Caledonian-Appalachian Orogen, eds. J. Hibbard, C. Van Staal and P. Cawood; Geological Association of Canada, Special Paper, p. 409-420. Murphy, J.B., Stokes, T.R., Meagher, C. and Mosher, S.J. 1994: The geology of the eastern St. Mary's Basin; in Eastern Canada and National and General Programs; Geological Survey of Canada, Current Research 1994-D, p. 95-102. Webster, T. 1996: Digital imagery and geology of the St. Mary's Basin, Nova Scotia; Acadia University, Nova Scotia. Webster, T., Murphy, J.B. and Barr, S.M. 1998: Anatomy of a terrane boundary: an integrated structural, GIS, and remote sensing study of the Avalon-Meguma terrane boundary, mainland Nova Scotia, Canada; Canadian Journal of Earth Sciences, v. 35, p. 787-801. BARRENS HILLS AND LITTLE STEWIACKE RIVER FORMATIONS (L@-E#Hbh/ls): undivided BARRENS HILLS FORMATION : resistant grey to grey-white weathering, fine- to very coarse-grained sandstone, monomict or polymict granulestone and conglomerate interstratified with recessive micaceous, grey to dark grey weathering shale and/or siltstone, minor red siltstone and sandstone. LITTLE STEWIACKE RIVER FORMATION : interstratified, thinly bedded, bioturbated mudstone, fissile, light to dark grey and black shale and slate, and light to dark grey sandstone containing comminuted plant debris. Selected References Open File Map ME 2005-111 Geological Map for Part of NTS 11E/07, Hopewell Area, Nova Scotia WINDSOR GROUP Outcrop data from Benson (1967), although not illustrated, were used locally to help support map interpretation. Map users should refer to Benson (1967) for additional outcrop locations and structural measurements. L@-E#Hbh/ls L@-E#Hgh L@-E#Hl Acknowledgments Bedrock units are not mapped in this map area * Geological Symbols Interfingering contact, approximate (units of approximately similar age, units of differing age) . . . . . . . . . . . . . . . . . . . . . ! ( ! ( !( ! ( !( ! ( ( ( ( ( ( Geological boundary (defined, approximate, assumed) . . . . . . . . Major fault (defined) . . . . . . . . . . . . . . . . . . Minor fault . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Anticline and syncline (approximate) . . . ® ® ® ® Minor fold axis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cleavage or foliation, 1st generation (inclined, vertical) . . . Intersection lineation, 1st generation . . . . . . . . . . . . . . . . . . . . . Bedding, tops unknown (inclined, vertical, horizontal) . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bedding, tops known (inclined, overturned, vertical, horizontal) . . . . . . . . . . . . . . . . Outcrop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Legend County Boundary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Railway Inactive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Railway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Trail/Footpath . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VehicleTrack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Loose Surface/Resource Access Road . . . . . . . . . . . . . . . . . Road Under Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hard Surface Road . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Collector Highway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Trunk Highway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Trans-Canada Highway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Series Highway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lakes, Single-line Rivers, Streams . . . . . . . . . . . . . . . . . . . . . 333 4 104 102 Coastline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Index Depression Contour . . . . . . . . . . . . . . . . . . . . . . . . . . . Depression Contour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Index Contour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Contour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . *

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HORTON GROUP

WEST RIVER ST. MARYS FORMATION

CROSS BROOK FORMATION*

GRAHAM HILL, LOCHIEL*, BARRENS HILLS and LITTLE STEWIACKE RIVER FORMATIONS

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((

((

((

((

Chedabucto Fault

L@-E#Hwr

L@-E#Hgh

L@-E#Hbh/ls

Pictou County

Colchester County

Pictou County

Guysborough County

Colchester County

Halifax County

Guysbourgh County

Halifax County

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Tim Lake

Ben Lake

Mud Lake

Long Lake

Hood Lake

Fish Lake

Drug Lake

Dean Lake

Dunn LakeDuck Lake

Perch Lake

Round Lake

Elbow Lake

Grant Lake

Piper Lake

Black Lake

Moose Lake

Perch Lake

Roops Lake

Jenny Lake

Little Lake

Calder Lake

Forbes Lake

Sucker Lake

Little Lake

Barren LakeDunbar Lake

Nelson Lake

Hattie Lake

Pictou Lake

Gordon Lake

Dryden Lake

Dickey Lake

Sucker Lake

Sammys Lake

Meadow Lake

Island Lake

Archies Lake

Caribou Lake

MacLean Lake

The Millpond

Russell Lake

Johnson Lake

McIntosh Lake

McKinnon Lake

Gairloch Lake

Long John Lake

Speichts Lakes

Porcupine Lake

Cranberry Lake

East Loon Lake

West Loon Lake

MacDonald Lake

Cranberry Lake

South Loon Lake

Botany Bay Lake

MacPhersons Lake

West Branch Lake

Ellen Brown Lake

North River Lake

Otter Brook Lake

Black Brook Lake

Bottle Brook Lake

Grandfathers Lake

Little Ellen Brown Lake

Castley Pools

Bezanson Stillwaters

Bill Weir Stillwaters

Rhynos Landing Stillwater

Lime Brook

Drug B

rook

Fall Brook

Jack Brook

Black Brook

Black Brook

Black River

Otter B

rook

Grants Brook

Gor

man

Bro

ok

Holmes Brook

Fulton Brook

Johnny Brook

Glencoe B

rook

Cro

oked

Bro

ok

Doggett Brook

Tannery Brook

Cameron Brook

Gairloch

Brook

Mahailas Brook

Watervale Brook

Mill

stre

am B

rook

East Bryden B

rook

Sam C

ameron Brook

Scrub Grass

Brook

Bog

I sl a

n d L

a ke

Bk

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Bra

nch

Cox Bro

ok

South Brook

Nelson River

Mea

dow

Bro

ok

Castley B

rook

Ben

tley

Bro

ok

Calvary River

Bla

ncha

rd B

rook

Archibald Brook

Upper Bryden Brook

West R

iver of Pictou

BIG

BR

OO

K

NORTH NELSON RIVER

EAST RIVER OF PICTOU

WES

T BR

ANC

H EA

ST R

IVER

MID

DLE R

IVER O

F PIC

TOU

Moiche Hill

Drug Brook Hill

Kincaid Mountain

Mount Thom

Elgin

Lorne

Eureka

Glencoe

Rocklin

Concord

St Pauls

Pembroke

Burnside

SunnybraeIron Rock

Coromonie

Trafalgar

Marshdale

New Lairg

Lansdowne

Eastville

Watervale

Brookville

Millstream

Centredale

White Hill

Springside

Springville

Graham Hill

New Gairloch

Gordon Summit

Upper Burnside

Websters Corner

Lansberg Siding

Campbells Siding

Island East River

Glengarry Station

Lansdowne Station

West River Station

Hopewell

Bridgeville

8570

Duck Lake

Maple Lake

Crane Pond

Round Lake

Beaver Lake

Semple Lake

McQuarrie Lake

Big Brook Lake

Lansdowne Lake

Little Johnson Lake

Beaver Bk

Sucker B

rook

McDonald Brook

McLellans Brook

Middle Bryden Brook

Little Branch Stewiacke Rive

r

Cox Brook

Map

le B

rook

Bryden Brook

Pembroke River

Sutherland Brook

Big B

ranch Stew

iacke River

STEWIAC

KE R

IVER

WEST RIVER ST MARYS

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Jun 07, 2005

Descriptive Text

63°00'

45°15'

62°30'

45°15'

45°30'

63°00' 62°30'

45°30'

Bay of F

undy

Atlantic Ocean

Gulf ofSt. Lawrence

NewBrunswick

P.E.I.

SableIsland

Nova Scotia

11F/0511E/0811E/0711E/06

Regional Key Map

Scale 1:50 0001 0 1 2 3 km

© Her Majesty the Queen in Right of the Province of Nova Scotia 2005

Halifax, Nova Scotia

62°45'

62°45'

45°22.5' 45°22.5'

100 0 100 km

The St. Marys Basin, central mainland Nova Scotia, is dominated by a Late Devonian(?) - Early

Carboniferous intracontinental alluvial fan-fluviatile-lacustrine basin-fill sequence that occupies the current

boundary between the Meguma and Avalon terranes of the Canadian Appalachians. The Basin rocks

belong to the Horton Group which is divided into six, partially laterally equivalent, formations. The

stratigraphically lowest rocks are predominantly exposed in the central part of the Basin in a series of en

echelon anticlinal closures (11E/06-08). These clastic rocks were deposited in a longitudinal drainage

system represented by a lacustrine (Little Stewiacke River Formation) and an overlying braided fluvial

(Barrens Hills, Lochiel and Graham Hill formations) environment, which are in turn overlain by the Cross

Brook and West River St. Marys formations. These rocks unconformably overly the Meguma Group,

reflecting a decrease in accommodation space and implying that the St. Marys Basin is underlain, at

least in part, by Meguma basement.

This map is predominantly underlain by the Little Stewiacke River and Barrens Hills formations. The

contact between these formations is exposed on this map on the Stewiacke River about 100 m south of

its intersection with highway 289. Facing directions in the vicinity of this contact clearly show that the

Barrens Hills Formation overlies the Little Stewiacke River Formation. However, contact relationships

between these formations are still being mapped out, so they are presented as an undivided unit on this

map. The Little Stewiacke River Formation, which consists of interstratified, thinly bedded, bioturbated

mudstone, fissile, light to dark grey and black shale and slate, and light to dark grey sandstone,

frequently contains abundant comminuted plant debris. Coarsening- and thickening-upward cycles,

2-25 m thick, occur with individual beds ranging in thickness from 2 mm to 15 cm. In some localities the

sandstones display soft sediment deformation. In many sections, the finer grained lithologies display a

slaty cleavage. Siltstone/shale-sandstone contacts are either sharp or transitional, or, less commonly,

erosional. Sandstones are typically grey or dark grey weathering, very fine- to fine-grained and micaceous,

and in some locations, moderately feldspathic. Primary and penecontemporaneous sedimentary features

include normal grading, parallel lamination, ripple crosslamination, loading features and bioturbation.

Sandstone strata generally vary from millimetres to decimetres in thickness. As the contact with the

overlying Barrens Hills Formation is approached, the upper member lithologies are coarser, erosionally

amalgamated with channel scours and possible swaley cross-stratification, and display large scale

(10-20 cm) trough cross-stratification. Fine, organic debris is often abundant in these sandstones and

their weathering colour darkens accordingly.

The Barrens Hills Formation is characterized by resistant intervals of light grey to grey-white

weathering, fine- to very coarse-grained sandstone, monomict or polymict granulestone and conglomerate

interstratified with recessive intervals of micaceous, grey to dark grey weathering shale and/or siltstone.

Interbeds of minor red siltstone and sandstone also occur. The sandstones are dominated by quartz and

feldspar, although grey sedimentary lithic clasts are common near the base of the Formation. Feldspars

are generally intensely weathered to clay minerals. Locally, the sandstones may be slightly micaceous,

moderately feldspathic, and contain varying, but significant amounts of dark grey sedimentary lithic

clasts of schist and sandstone, some with a fabric, that are probably derived from the Meguma Terrane

south of the St. Marys Basin. The Barrens Hills Formation underlies large areas of both the central and

eastern Basin where it outcrops along a broad, regional, northeastward-trending anticlinal axis. To the

west of the Stewiacke River region the Formation thins dramatically and passes into the laterally

equivalent Graham Hill Formation. To the east of this map sheet, it passes into the laterally equivalent

Lochiel Formation.

The basal contact of the Barrens Hills Formation is positioned where sand- to granule-sized quartz-rich

clastic sediment starts to predominate over the darker and more thinly bedded lithologies of the Little

Stewiacke River Formation. This contact is exposed in the Stewiacke River region (11E/07) where it is

transitional over 1 m. It is recognized by the abrupt occurrence of thin (10-20 cm) lenses of small pebble

conglomerate at the base of the Barrens Hills Formation.

In the western portion of the map, the Graham Hill Formation consists of 1220 m of red and

maroon weathering, finer grained litharenite to feldspathic litharenite and siltstone with thick intervals of

grey weathering, interstratified, coarser grained sandstone, pebbly sandstone and granule to pebble

conglomerate. Clasts include quartz, mica, intraformational siltstone (0.5-1 cm), and flow-banded rhyolite.

Regional relationships indicate that the Graham Hill Formation is also a lateral facies equivalent of the

Barrens Hills Formation. In separate stratigraphic sections, both formations conformably overlie the Little

Stewiacke River Formation. In the eastern portion of 11E/06, the Graham Hill Formation is complexly

interstratified with both the Barrens Hills and Little Stewiacke River formations. This indicates that the three

formations are, at least in part, time equivalents. This style of interfingering is thought to characterize the

stratigraphic relationships between formations throughout the Basin.

The Cross Brook Formation consists of grey-green weathering sandstone interstratified with less

abundant grey-green weathering siltstone, shale and conglomerate and rare limestone. The Cross Brook

Formation is not exposed in this map area, but further east it occurs along the southern flank of the Basin.

The sandstones are typically fine- to coarse-grained, micaceous, variably feldspathic, and locally contain

varying amounts of granule-sized quartz and sedimentary/metasedimentary lithic fragments. They generally

are thinly bedded and commonly display ripple crosslamination, and trough cross-stratification in sets up

to 1 m thick. Pebble conglomerates are polymict, poorly sorted and framework supported. Dominant clast

types in the sandstones and conglomerates include psammite, pelite, micaceous granite, vein quartz and

muscovite. Less abundant, sedimentary clasts include laminated carbonaceous mudstone (possibly of

algal origin), siltstone, sandstone, carbonate and organic debris, all of which are interpreted as intrabasinal

detritus. Most clasts are subangular to subrounded. Siltstone and shale beds are grey weathering,

micaceous and display parallel lamination and ripple crosslamination.

The West River St. Marys Formation consists of reddish-brown to grey-brown weathering conglomerate

interstratified with grey-brown weathering sandstone. The Formation outcrops along the southern flank of

the central and eastern portions of the Basin. The red-brown to grey-brown weathering conglomerate

contains clasts ranging from pebbles to boulders. The rock is dominantly framework- to locally matrix-

supported with a roughly 80:20 framework to matrix ratio. It is very poorly to poorly sorted, may contain

imbricated pockets, or display crude inverse- to normal-grading. The conglomerate contains numerous,

major scour surfaces and fines upward to large pebble-size in the top of the measured section. Basal

contacts with sandstone lenses are erosional. Clast shape and size vary with composition. Sedimentary

clasts are largest (sandstone to 90 cm, shale/siltstone to 6 cm) and are subrounded to subangular.

Metasedimentary clasts are similar in shape, but generally smaller in size. Granite and quartz clasts are

rounded to well-rounded, the latter reaching 30 cm in diameter. Sandstone clasts are dominantly

grey-green weathering, fine- to medium-grained, micaceous and feldspathic. In some instances they exhibit

postdepositional en echelon tension fractures. Clast counts also indicate that metasedimentary clasts are

marginally more dominant in the west and sedimentary clasts are more dominant in the east.

Metasedimentary clasts are dominantly dark grey weathering pelite, commonly with an inherited tectonic

fabric. The matrix is grey-brown weathering, medium- to very coarse-grained, feldspathic, lithic sandstone.

Conglomerates further upsection are finer grained and better organized, displaying imbrication and

trough cross-stratification. In the eastern portion of the Basin, these conglomerates contain a significant

amount of plant debris including fragments up to 30 cm long. Sandstone occurs as trough-shaped lenses

up to approximately 2 m thick, characteristically 30-80 cm thick, with a minimum lateral extent of 15 m.

The lenses are grey-green weathering, medium- to very coarse-grained, feldspathic and micaceous.

Occasional interstratified pebbly or granulestone horizons occur. Scours, trough cross-stratification

(sets to 30 cm), ripple cross-stratification and normal grading all occur in the sandstone. The number of

sandstone lenses increases upsection.

The deposition of coarse conglomerates occurs along the southern flank of the Basin suggesting a

strong tectonic influence on sedimentation where subsidence along this Basin margin occurs along

northerly dipping listric normal faults. In contrast, the character of the sediments does not vary with

proximity to the northern margin (Chedabucto Fault) suggesting that the Fault does not constitute the

J. B. Murphy and R. J. Rice

Recommended Citation

Map Notes

Universal Transverse Mercator Projection (UTM), Zone 20, Central Meridian 63°00' West.

Base and digital data derived from the Nova Scotia Topographic Database (NSTDB). The NSTDB is

available from Service Nova Scotia and Municipal Relations (SNSMR), Land Information Services

Division (LIS), Nova Scotia Geomatics Centre (NSGC), Amherst, Nova Scotia.

We acknowledge the support of the Geological Survey of Canada, Natural Sciences and Engineering

Research Council, Caledonia Mining Corporation and the Nova Scotia Department of Natural Resources.

We are grateful to David Dowe, Samantha Evans, Lorne Jennex, Fraser Keppie, Jon Malone, Sarah

Jane Mosher, Cashel Meagher, Alex Nazck, Jacquie Stevens, Tim Stokes and Tim Webster for

assistance in the field.

Map production funded by Natural Resources Canada and Nova Scotia Department of Natural

Resources under the Targeted Geoscience Initiative (Phase 2) Project: Geological Mapping and

Resource Evaluation in Central Nova Scotia, 2004-2005.

Cartography and reproduction by Nova Scotia Department of Natural Resources, Geoscience

Information Services Section, 2004-2005.

North American Datum (NAD) 1927.

Disclaimer

The information on this map may have come from a variety of government and nongovernment

sources. The Nova Scotia Department of Natural Resources does not assume any liability for

errors that may occur.

±

LEGEND

CARBONIFEROUS

LATE DEVONIAN - EARLY CARBONIFEROUS

undivided

reddish-brown to grey-brown weathering, pebble to boulder conglomerate interstratified with grey-brown weathering sandstone. Abundant clasts derived from the Meguma Terrane.

grey-green weathering sandstone, interbedded grey-green weatheringsiltstone, shale, conglomerate and rare limestone. Abundant clasts derived from the Meguma Terrane.

Map Area..................

NTS Map Sheets......

Study Area................

GRAHAM HILL FORMATION (L@-E#Hgh): red and maroonweathering, finer grained litharenite to feldspathic litharenite and siltstone with thick intervals of grey weathering, interstratified, coarsergrained sandstone, pebbly sandstone and granule to pebble conglomerate. Clasts include quartz, mica, intraformational siltstone (0.5-1 cm), and flow-banded rhyolite. LOCHIEL FORMATION* (L@-E#Hl): grey or green, fine- to very coarse-grained, micaceous and feldspathic sandstones, interbedded minor granulestone, dark grey siltstone.

E#W

L@-E#Hcb

L@-E#Hwr

Nova Scotia Department of Natural ResourcesMineral Resources Branch

Murphy, J.B. and Rice, R.J. 2005: Geological map for part of NTS 11E/07, Hopewell

area, Nova Scotia; Nova Scotia Department of Natural Resources, Mineral Resources Branch,

Open File Map ME 2005-111, scale 1:50 000.

original Basin margin, and that an unknown portion of the Basin and its Meguma basement have been

tectonically removed and may be found north of the Fault.

The St. Marys Basin is an example of basin development and evolution adjacent to an intracontinental

fault zone associated with oblique convergence during orogenesis. Its evolution provides constraints on

the potential relationship between the termination of the mid-Paleozoic Acadian Orogeny, subsequent

basin development and the ongoing interactions between the Avalon and Meguma terranes, and between

Laurentia and Gondwana during the assembly of Pangea. More generally, because the relationship

between fabric development and motion along intracontinental strike-slip faults in continental zones is

difficult to interpret, the sedimentology and structural geology in basins developed along these fault

zones may preserve a less ambiguous record of the main tectonic events.

The evolution of the St. Marys Basin preserves evidence of protracted dextral shear along an

intracontinental fault zone during collisional orogenesis and the assembly of Pangea. The origin and

evolution of the Basin are attributed to either discrete or progressive dextral strike-slip tectonics along the

Minas Fault Zone (MFZ) between the Late Devonian and Late Carboniferous. Evidence for the Late

Devonian origin of the Basin is recorded along its southern flank by the fabrics of the deformed

ca. 370 Ma granites, the overall sedimentary facies distribution and some syndepositional features

within the clastic rocks. The most intense deformation within the Basin is concentrated in a narrow

east-northeastward-trending zone, in which predominantly fine grained clastic rocks are deformed into

periclinal folds and related reverse faults. The orientation of this zone, relative to the MFZ, is consistent

with dextral shear. At least some of this deformation occurred after the deposition of the overlying

Viséan Windsor Group (11E/06). The style of deformation along the present northern margin of the

Basin (the Chedabucto Fault) is also consistent with regional dextral shear.

Benson, D.G. 1967: Geology of the Hopewell map area, Nova Scotia; Geological Survey of Canada,

Memoir 343, 58 p. and Map 1215A, scale 1:63 360

Benson, D.G. 1974: Geology of the Antigonish Highlands, Nova Scotia; Geological Survey of Canada,

Memoir 376, 92 p.

Fletcher, H. and Faribault, E.R. 1887: Geological surveys and explorations in the counties of

Guysborough, Antigonish, Pictou, Colchester and Halifax, Nova Scotia from 1882-1886; Geological

Survey of Canada, Annual Report, v. II, 1886, pt. P, p. 5-128.

Jennex, L.C. 1998: Geological and geophysical investigation of the western St. Mary's Basin,

central mainland Nova Scotia: implications for paleoplacer gold potential; unpublished M.Sc.

thesis, St. Francis Xavier University, Nova Scotia, 286 p.

Jennex, L.C., Murphy, J.B. and Anderson, A.J. 2000: Post-orogenic exhumation of an auriferous

terrane: the paleoplacer potential of the Early Carboniferous St. Marys Basin, Canadian Appalachians;

Mineralium Deposita, v. 35, p. 776-790.

Murphy, J.B. and Rice, R.J. 1998: Stratigraphy and depositional environment of Horton Group rocks in

the St. Mary’s Basin, central mainland Nova Scotia; Atlantic Geology, v. 34, p. 1-26.

Murphy, J.B., Rice, R.J., Stokes, T.R. and Keppie, D.F. 1995: The St. Mary's Basin, central mainland

Nova Scotia: Late Paleozoic basin formation and deformation along the Avalon-Meguma terrane

boundary, Canadian Appalachians; in New Perspectives in the Caledonian-Appalachian

Orogen, eds. J. Hibbard, C. Van Staal and P. Cawood; Geological Association of Canada, Special Paper,

p. 409-420.

Murphy, J.B., Stokes, T.R., Meagher, C. and Mosher, S.J. 1994: The geology of the eastern St. Mary's

Basin; in Eastern Canada and National and General Programs; Geological Survey of Canada,

Current Research 1994-D, p. 95-102.

Webster, T. 1996: Digital imagery and geology of the St. Mary's Basin, Nova Scotia; Acadia University,

Nova Scotia.

Webster, T., Murphy, J.B. and Barr, S.M. 1998: Anatomy of a terrane boundary: an integrated structural,

GIS, and remote sensing study of the Avalon-Meguma terrane boundary, mainland Nova Scotia, Canada;

Canadian Journal of Earth Sciences, v. 35, p. 787-801.

BARRENS HILLS AND LITTLE STEWIACKE RIVER FORMATIONS (L@-E#Hbh/ls): undivided BARRENS HILLS FORMATION: resistant grey to grey-whiteweathering, fine- to very coarse-grained sandstone, monomict or polymict granulestone and conglomerate interstratified with recessive micaceous, grey to dark grey weathering shale and/or siltstone, minor red siltstone and sandstone. LITTLE STEWIACKE RIVER FORMATION: interstratified, thinly bedded, bioturbated mudstone, fissile, light to dark grey and black shale and slate, and light to dark grey sandstone containing comminuted plant debris.

Selected References

Open File Map ME 2005-111

Geological Mapfor Part of NTS 11E/07,

Hopewell Area, Nova Scotia

WINDSOR GROUP

Outcrop data from Benson (1967), although not illustrated, were used locally tohelp support map interpretation. Map users should refer to Benson (1967) foradditional outcrop locations and structural measurements.

L@-E#Hbh/lsL@-E#Hgh L@-E#Hl

Acknowledgments

Bedrock units are not mapped in this map area*

Geological Symbols

Interfingering contact, approximate (units of approximately similar age, units of differing age) . . . . . . . . . . . . . . . . . . . . .

!(

!(

!( !(

!(

!( (( (

(

(

Geological boundary (defined, approximate, assumed) . . . . . . . .

Major fault (defined) . . . . . . . . . . . . . . . . . .

Minor fault . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Anticline and syncline (approximate) . . . ®®

®

®

Minor fold axis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Cleavage or foliation, 1st generation (inclined, vertical) . . .

Intersection lineation, 1st generation . . . . . . . . . . . . . . . . . . . . .

Bedding, tops unknown (inclined, vertical, horizontal) . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Bedding, tops known (inclined,overturned, vertical, horizontal) . . . . . . . . . . . . . . . .

Outcrop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Legend

County Boundary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Railway Inactive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Railway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Trail/Footpath . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

VehicleTrack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Loose Surface/Resource Access Road . . . . . . . . . . . . . . . . .

Road Under Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Hard Surface Road . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Collector Highway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Trunk Highway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Trans-Canada Highway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

100 Series Highway . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Lakes, Single-line Rivers, Streams . . . . . . . . . . . . . . . . . . . . .

333

4

104

102

Coastline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Index Depression Contour . . . . . . . . . . . . . . . . . . . . . . . . . . .

Depression Contour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Index Contour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Contour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

*