The vegetation is of the tundra type, with outliers of the boreal spruce forest; willow thickets line the course of the Old Crow River. Geologically the plain represents the floor of the intermontane Old Crow Basin, a structural depression of Tertiary age linking the Eastern and Interior Systems of the Cordillera. The basin is bordered on the east by the Richardson Mountains, on the north by the British Mountains and on the west and south by the Old Crow Range. The underlying sediments include a veneer of Holocene and Pleistocene clays, silts, sands and organics, overlying a thick sequence of Tertiary, Mesozoic and Palaeozoic sediments and sedimentary rocks, some of which are potentially oil bearing.
The basin was one of the few areas in Canada untouched by glaciation during the Pleistocene ICE AGES, and it served as a refuge for many ice-age animals. However, abandoned high-level shorelines indicate that the flats were inundated by proglacial lakes during the ice ages. The modern Old Crow River, which joins the Porcupine River at the native village of OLD CROW, is a meandering stream with numerous cutoffs and a well-defined terrace system. The river bluffs have yielded an enormous quantity of mammalian bones, together with artifacts of PREHISTORY.
Author ALAN V. JOPLING
Links to Other Sites
Environmental Change and Traditional Use of the Old Crow Flats in Northern Canada
See an article about a joint community–researcher investigation of environmental change and traditional use of the Old Crow Flats in the Yukon. A Government of Canada International Polar Year project. From the journal "Arctic," published by the Arctic Institute of North America at the University of Calgary.