Bedrock geology of the Lake Tapps quadrangle, Pierce County, Washington

Abstract

Page PLATE1. Map and sections showing bedrock geology and structure of part of the Lake Tapps quadrangle._____ _ _ _ In pocket 2. Geologic map and sections of a potential damsite at Fairfax Bridge.

Petrology and stratigraphy of Paleogene nonmarine sandstones, Cascade Range, Washington

“…(Mullineaux, 1970) and is, in part, correlative with others to the south (cf. Gard, 1968;Snavely, and others, 1958;and Buckovic, 1979).…”

Flood potential of South Prairie Creek, Pierce County, Washington

“…The subsurface geology consists primarily of sedimentary and volcanic rock from the Eocene (the Puget Group, which includes the Spiketon, Northcraft, and Carbonado Formations), the Oligocene (Ohanapecosh Formation) and the Miocene (volcanic mudflow deposits) (Card, 1968). The surface geology consists mostly of unconsolidated Pleistocene glacial-drift deposits known as the Vashon Drift (Crandell, 1963), with small areas of mudflow deposits.…”

Provenance study of late Eocene arkosic sandstones in southwest and central Washington

“…Previous workers have mapped a number of Eocene arkosic units in southwest and central Washington, including the Puget Group (Gard, 1968;Buckovic, 1979), Roslyn Formation (Bressler, 1951), Mcintosh Formation (Snavely and others, 1958), Carbonado Formation (Gard, 1968), Chumstick…”

“…Formation , Naches Formation (Frizzell, 1979;Hammond, 1980), Skookumchuck Formation (Snavely and others, 1958), Summit Creek sandstone (Clayton, 1983), Renton Formation (Vine, 1962), Tiger Mountain Formation (Vine, 1962), and the Spiketon Formation (Gard, 1968).…”

“…Formation, Naches Formation, and Carbonado Formation in central and southwestern Washington (Figure 1). These deposits are Eocene in age, light gray to pale brown in color, arkosic to lithic arkosic in composition, and all except the Carbonado Formation -which was deposited in a near shore marine environment -were deposited in nonmarine fluvial and braided stream environments (Snavely and others, 1951;Gard, 1968;Gresens and others, 1981;Clayton, 1983;Tabor and others, 1984). The purposes of this study are: 1) to compare these four formations in terms of their light and heavy mineral assemblages and trace element contents, in order to determine if these sediments were derived from the same provenance; and 2) to determine the composition of the source rocks based on the light and heavy mineral assemblages, in hopes of identifying the sauce areas.…”