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<br />0938 <br /> <br />Points Member, and near the northwestern corner of the basin it grades into <br />". - ...- - .>- <br />the overlying Garden Gulch Member. <br />3.5.1.2.2 Garden Gulch Member <br />., <br /> <br />The Garden Gulch Member is composed mainly of gray to black shales, <br />usually paper-thin and fissile. Lesser amounts of marl stone, thin <br />sandstones, and limestones are also noted. Low-grade oil shales of the <br />Garden Gulch Member-yieli1-is"iiiuch-a"S15'galloils of 'oil 'per ton of rock <br />(Merriam, 1954). <br /> <br />The Garden Gulch Member is 700 feet thick in the valley of Parachute <br />Creek, near the town of Parachute (formerly Grand Valley). Outcrops of <br />this member range in thickness from 100 to 900 feet, extend from Parachute <br />Creek westward and around the edges of the basin to the center of the <br />northern rim. The Garden Gulch Member grades eastward into the Anvil <br />Points Member. On outcrop, it is generally slope forming, in contrast to <br />the overlying and underlying members which are generally cliff-forming. <br />The contact with the underlying Douglas Creek MemBer is gradational. In <br />the center of the basin, where the Douglas Creek Member is absent, the <br />Garden Gulch Member lies conformably on the Wasatch Formation. The contact <br />with the overlying Parachute Creek Member is also conformable (Merriam, <br />1954; McDonald, 1972; Tosco, 1979). <br /> <br />3.5.1.2.3 Anvil Points Member <br /> <br />The Anvil Points 'Member is a heterogeneous clastic unit, 1,500 to <br />1,900 feet thick. It crops out along the northeast, east, and southeast <br />sides of the basin and pinches out within 8 to 12 miles of its outcrop. <br />The Anvil Points Member is a shoreline facies which interfingers with and <br />, grades into the Douglas Creek, Garden Gulch, and lower Parachute Creek <br />Members. This member, named by Donnell (1953), has its type area at Anvil <br />Points, immediately south of NOSR 1. It interfingers with the underlying <br />W\satch Formation and the overlying Parachute Creek Member. A 40 to 50 <br />foot thick sandstone tongue of the Anvil Points Member, with a slightly <br />greater areal extent, has been referred to as the Piceance Creek Sandstone <br />IRitzma, 1965). <br /> <br />3-10 <br />