Pacific Stoneware Company, Multnomah Co., Oregon, USA

Age: Pleistocene (0 - 2.588 Ma)

Description: Catastrophic flood deposits, fine grained facies; 30m thick; fine grained sediments

Lithology: Major:: {mixed catastrophic flood sand, Columbia River Basalt clasts clasts; weathering: brown clay and iron oxide 1-6cm thick; quartz, feldspar, white mica grains}; Major:: {mixed catastrophic flood silt, Columbia River Basalt clasts clasts; weathering: brown clay and iron oxide 1-6cm thick; quartz, feldspar, white mica grains}

Reference: R.L. Smith, W.P. Roe (compilers). Oregon Geologic Data Compilation, release 6. State of Oregon Department of Geology and Mineral Industries. [20]

Age: Pleistocene (0.0117 - 2.588 Ma)

Stratigraphic Name: Willamette Silt; Gresham Formation; Estacada Formation

Description: Unconsolidated to semiconsolidated lacustrine clay, silt, sand, and gravel; in places includes mudflow and fluvial deposits and discontinuous layers of peat. Includes older alluvium and related deposits of Piper (1942), Willamette Silt (Allison, 1953; Wells and Peck, 1961), alluvial silt, sand, and gravel that form terrace deposits of Wells and others (1983), and Gresham and Estacada Formations of Trimble (1963). Includes deltaic gravel and sand and gravel bars, in pluvial lake basins in southeastern part of map area. In Rome Basin, includes discontinuous layers of poorly consolidated conglomerate characterized by well-rounded, commonly polished pebbles of chert and pebbles and cobbles of quartzite. In places contains mollusks or vertebrate fossils indicating Pleistocene age; mostly deposits of late Pleistocene age, but locally includes some deposits of early Holocene age. Includes Touchet Beds of Flint (1938), deposits of valley terraces of Newcomb (1965), and, in southeast Oregon, basin-filling deposits that incorporate Mazama ash deposits (Qma, Qmp) in the youngest layers

Lithology: Major:{clay,silt,sand}, Minor:{gravel}, Incidental:{peat}

Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052. [133]