The West Escarpment diatomite occurrence is located on the west side of the Deadman Valley west of Snohoosh Lake, below the basalt escarpment. The area is accessible on a good-quality gravel road north from the Trans-Canada Highway, 7.4 kilometres west of Savona, 43 (air) kilometres to the south.
Basalts of the Miocene Chasm Formation (Chilcotin Group) mantle most of the area, however, beneath the basalts, massive rhyolite ash of the Miocene Deadman River Formation (Chilcotin Group) forms a section more than 200 metres in thickness on the east side of the valley. The rhyolite ash is the predominant lithology in a Miocene channel filling of fluviatile and lacustrine sediments occupying the northwest trending Mio-Snohoosh Channel (Open File 1989-21). A section measured by Campbell and Tipper contained a minimum aggregate thickness of 3.8 metres of diatomaceous earth in two beds lying within 50.9 metres of the base of the section (Geological Survey of Canada Memoir 363, pages 58 and 59).
Economic interest in the Miocene section in the Deadman Valley has been directed mainly towards the volcanic ash/pozzolan potential of the Miocene section immediately overlying the lacustrine diatomite (see Sherwood Creek Volcanic Ash, 092P 093).
One bedrock and two float occurrences of diatomite have been documented (Read, 1990) in the area: The "West Escarpment" showing (5661550mN, 647890mE) is a bedrock occurrence located at the base of the western basalt escarpment. A three metre thick flat lying rhyolite ash and a 0.7 metre thick diatomaceous earth bed occur immediately between basalt flows of the Chasm Formation. The Moose Creek North 1 occurrence (5662525mN, 646400mE) consists of float found on an old logging road in an area of no outcrop and appears to have come from an interflow unit between basalt flows. Abundant diatoms were identified in oil immersion mounts of samples of the material. The Moose Creek North 2 occurrence (5661570mN, 646570mE) is a "slumped outcrop" exposed in an old roadcut. It appears to have come from an interflow unit between basalt flows. Abundant diatoms were identified in oil immersion mounts of samples of the material.