Sr. Hicock et Ob. Lian, THE SISTERS-CREEK FORMATION - PLEISTOCENE SEDIMENTS REPRESENTING A NONGLACIAL INTERVAL IN SOUTHWESTERN BRITISH-COLUMBIA AT ABOUT 18 KA, Canadian journal of earth sciences, 32(6), 1995, pp. 758-767
Sisters Creek Formation is formally defined, stratotypes are establish
ed for it, and the time-space chart is updated for the Fraser Lowland,
southwestern British Columbia. The Sisters Creek is a Pleistocene for
mation comprising in situ and reworked organic-rich sediments, and non
organic silt, sand, and gravel. The formation was deposited during the
Port Moody interstade (within the Late Wisconsinan Fraser Glaciation;
delta(18)O stage 2) between the Coquitlam stade (early Fraser Glaciat
ion) and the main Vashon stadial maximum that occurred about 14.5 ka.
The Sisters Creek Formation represents a glacial recession in southwes
tern British Columbia that generally coincided with the timing of the
last global glacial maximum. The new time-space chart implies that, in
Fraser Lowland, the Fraser Glaciation represents the rapid advances a
nd retreats of glacial lobes issuing from surrounding mountains, which
remained ice-covered during interstades.