Pleistocene sequence in southeastern part of the Puget Sound lowland, Washington

Abstract

Sound lowland has resulted in a refinement and expansion of the sequence originally described by Willis in 1898. Willis' t1equence of <two glaciations (Admiralty and Vashon) and a single interglacial interval (Puyallup) is replaced by four glaciations separated by nonglacial intervals during which the climate approached or attained conditions like those of the present. The stratigraphic section now recognized consists of the Orting drift (oldest), Alderton formation {nonglacial), Stuck drift, Puyallup formation {nonglacral) , SaJmon Springs drift and Vashon ckirt. An erosion interval bet ween the Salmon Springs and Vashon drifts is thought to represent the third nonglacial interval. The name Admiralty is not used in this paper because the stratigraphic position of the drift assigned to this glaciation by Willis appears to be equivocal in the sequence now recognized.

Geology of the Renton, Auburn, and Black Diamond quadrangles, King County, Washington

“…The valleys were then modified by the Vashon glacier and were drowned by submergence. Hansen and Mackin (1949), Sceva (1957), and Crandell, Mullineaux, and Waldron (1958) confirmed that the valleys were cut into an overall fill, but they showed that the fill consisted of deposits of several different glacial and nonglacial episodes. No evidence was found to negate Bretz' hypothesis of pre-Vashon origin by fluvial erosion caused by uplift, and of only modification of the valleys by the Vashon glacier.…”

Chronostratigraphy of glaciations and permafrost episodes in the Cordillera of western North America

“…The Sherwin till in California (Blackwelder, 1931) underlies the Bishop ash bed at its type locality (Sharp, 1968), so it must also be of this age, while the Dyer till in the White Mountains has also been dated at c. 1.0a (Elliot-Fish, 1987). The Salmon Springs drift of Washington State (Crandell et al, 1958) is interbedded with the Lake Tapps tepha dated at 0.8-0.9 Ma (VTlestgate et al, 1987), and is probably Nebraskan in age. The till buried by lava dated at 0.7 Ma in the Mt Garibaldi volcanic belt (Green et al, 1988) is probably of this age.…”

Advance and Retreat of Cordilleran Ice Sheets in Washington, U.S.A.

“…The chronology of the advance and retreat of the Late Wisconsinan Fraser Glaciation in the Puget Lowland has been worked out over the past several decades (Armstrong et al, 1965;Crandell et al, 1958;Blunt et al, 1987;Easterbrook, 1963Easterbrook, ,1969Easterbrook, ,1986Easterbrook ef a/., 1981Easterbrook ef a/., ,1988Mullineauxef al., 1965;Westgate et al, 1987), and now comprises one of the best-dated, long-record, Pleistocene sequences in the world. However, papers published during the same time period on interpretations of specific depositional environments of some of the sediments have not always been in accord with one another.…”