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TitleQuaternary geology, Cape Breton Island, Nova Scotia
AuthorGrant, D R
SourceGeological Survey of Canada, Bulletin 482, 1994, 159 pages (2 sheets), (Open Access)
PublisherNatural Resources Canada
MapsPublication contains 1 map
Map Info.surficial geology, lithology, landforms, 1:125,000
ProjectionUniversal Transverse Mercator Projection
Mediapaper; on-line; digital
RelatedThis publication contains Grant, D R; (1988). Surficial geology, Cape Breton Island, Nova Scotia, Geological Survey of Canada, "A" Series Map no. 1631A
File formatpdf
ProvinceNova Scotia
NTS11J/04; 11J/05; 11K/01; 11K/02; 11K/03; 11K/04; 11K/05; 11K/06; 11K/07; 11K/08; 11K/09; 11K/10; 11K/11; 11K/14; 11K/15; 11F/09; 11F/10; 11F/11; 11F/14; 11F/15; 11F/16; 11G/13
AreaCape Breton Island
Lat/Long WENS -61.5000 -59.5000 47.0833 45.5000
Subjectssurficial geology/geomorphology; geochronology; organic deposits; colluvial deposits; tills; fluvial deposits; marine deposits; lacustrine deposits; glaciolacustrine deposits; glaciofluvial deposits; tills; glacial striations; moraines; drumlins; eskers; Wisconsinian Glacial Stage; glacial stages; Sangamonian Interglacial Stage; interglacial stages; glaciation; deglaciation; glacial deposits; stratigraphic analyses; uranium thorium dates; radiocarbon dates; radiometric dates; ice movement directions; glacial history; erosion; landforms; Quaternary
Illustrationssketch maps; photographs; cross-sections; aerial photographs
Released1994 12 01; 2013 11 07
AbstractTertiary planation and uplift exhumed two unconformities (paleoplains) and produced two peneplains into which Quaternary glaciation excavated submarine basins and channels. The last interglaciation deposited organic beds and cut an intertidal rock bench and littoral gravel, now emerged 2-7 m. The nonglacial period spanned 126-47 ka BP according to 30 Th/U and 14C wood ages at 16 sites. Two temperate cycles climaxed 125 and 86 ka BP and are correlated to oxygen isotope substages 5e and 5a; the first had hardwood forest reflecting a warmer than present climate; the second had boreal forest like today. Early-Middle Wisconsinan time is recorded by three tundra/boreal forest alternations, reflecting climatic deterioration until Wisconsinan glaciers arrived 62-47 ka BP. Several ice flow phases left crosscutting striations, superimposed drumlins and fluting, and three main till sheets of differing lithology, colour, texture, and provenance. An ice cap began on the highlands, then an ice sheet from mainland Nova Scotia advanced eastward and deposited a red foreign till on the lowlands. South-flowing regional ice (Laurentide?) crossed the island; it was cold-based on the highlands and preserved preglacial soil and landforms. Weathered striations beneath fresh till suggest an ice free interval. A northward flow from Scotian Shelf which introduced shell fragments may have signalled an ice rise, a flow reversal due to drawdown, or a new ice dome on the emergent shelf. The ice divide shifted onshore forming a Bras d'Or Lake centre. Gulf of St. Lawrence ice on the west coast dammed lakes that drained northward. Climatic cooling 11-10 ka caused glacial readvance and renewed solifluction. Highland ice lasted until 8-9 ka and Neoglacial cirque glaciers may have formed. Neotectonics tilted the bench southward and displaced it 15 m at Aspy Fault. Submerged features, geodetic relevelling, and tide gauging show a relative sea level rise of 20-70 cm/100 a due glacial forebulge collapse. Unstable slopes have landslides and sagging cliffs.