Map 417

Map 417

MAP 417

Drift Thickness of Bistcho Lake Area, Alberta (NTS 84M)

Author(s) Pawlowicz, J.G. Nicoll, T.J. Sciarra, J.N. Date 2007-05-28

The drift thickness map shows the variation in thickness of unconsolidated sediment lying between the bedrock surface and present-day land surface, and complements the 1995 Drift Thickness of Alberta map by Pawlowicz and Fenton. Throughout the entire map area, the bedrock is blanketed by drift, with the exception of a few outcrops and thin till veneers along the south flank of the uplands. The drift is also relatively thin (<25 metres)="" in="" the="" hay="" river="" plain="" adjacent="" to="" the="" uplands,="" where="" glacial="" erosion="" was="" more="" persistent="" than="" deposition.="" much="" thicker="" drift="" is="" found="" in="" the="" buried="" valleys="" and="" beneath="" portions="" of="" the="" hills="" in="" the="" uplands.="" the="" bedrock="" topography="" map="" of="" the="" bistcho="" lake="" area="" shows="" the="" location="" of="" the="" major="" buried="" valleys.="" thickest="" drift="" of="" 351="" metres="" was="" recognized="" in="" a="" well="" in="" township="" 123="" and="" range="" 1="" in="" the="" cameron="" hills.="" as="" well,="" over="" 300="" metres="" of="" drift="" was="" found="" in="" a="" number="" of="" wells="" along="" the="" major="" bistcho="" paleovalley.="" the="" shekilie="" valley="" is="" another="" major="" paleovalley="" in="" the="" cameron="" hills="" uplands="" and="" contains="" slightly="" less="" drift="" of="" between="" 200="" and="" 300="" metres.="" the="" amber,="" moody="" and="" adair="" valleys="" are="" other="" buried="" valleys="" in="" the="" south="" part="" of="" the="" map="" area;="" however,="" drift="" thickness="" in="" these="" is="" less="" than="" 150="" metres.="" the="" present-day="" land="" surface="" with="" great="" expanses="" of="" broad="" low-lying="" areas="" shows="" little="" evidence="" of="" these="" buried="">