Interim Geologic Map of the West Part of - Utah Geological Survey

quadrangle, 80 to 165 feet (24-50 m) thick in the Asay Bench quadrangle (Mooreand others, 1994), about 150 to 180 feet (45-55 m) thick in the Henrie Knollsquadrangle (Biek and others, 2007), but only 45 to 60 feet (14-18 m) thick atCedar Breaks (Schneider, 1967; Moore and others, 2004; Rowley and others, inpreparation) and about 30 feet (10 m) thick in the southern Red Hills (Threet,1952).Tcwml Lower limestone interval and middle mudstone, siltstone, and sandstoneinterval of white member, undivided (Eocene) – Locally undivided at CedarBreaks National Monument due to map scale, and in the northwest part of theHenrie Knolls quadrangle due to poor exposure; as mapped, less than about 250feet (75 m) thick.Tcwm Middle mudstone, siltstone, and sandstone interval of white member (Eocene)– Varicolored and commonly mottled, pale-reddish-orange, reddish-brown,moderate-orange-pink, yellowish-gray, dark-yellowish-orange, and grayish-pinkcalcareous mudstone and siltstone, and minor fine-grained calcareous sandstoneand chert-pebble conglomerate that weathers to a poorly exposed slope; upperconformable contact corresponds to a pronounced color change from brightlycolored reddish-orange mudstone and siltstone below to white to very pale orangemicritic limestone above; queried at the south end of the Red Hills, and nearWillow Creek northeast of Paragonah; about 120 feet (36 m) thick near CameronTroughs south of Panguitch Lake, but appears to thin abruptly to about 50 feet (15m) thick about one mile (1 km) to the north; at Cedar Breaks National Monument,Schneider (1967) measured 227 feet (69 m) of strata we assign to Tcwm, butRowley and others (in preparation) reported that this interval is 310 feet (94 m)thick in this same area; Moore and others (1994) reported that their middle sandyunit is 175 to at least 220 feet (54-67 m) thick in the Asay Bench quadrangle.Tcwl Lower limestone interval of white member (Eocene) – Micritic limestonesimilar to the upper white limestone interval (Tcwu); forms cliff or steep, ledgy,white slope above more colorful but typically subdued slopes of the red member(Tcr); contains sparse charophytes; upper conformable contact corresponds to apronounced color change from white to very pale orange micritic limestone belowto brightly colored reddish-orange mudstone and siltstone above; query indicatesuncertain identification on Navajo Ridge, at the south end of the Red Hills, andnear Willow Creek northeast of Paragonah; about 100 to 120 feet (30-35 m) thickin the upper reaches of Rock Canyon; Moore and others (1994) reported that theirlower white limestone is generally 85 to 120 feet (26-36 m) thick, but as much as180 feet (55 m) thick, in the Asay Bench quadrangle; only about 47 feet (14 m)thick at Cedar Breaks National Monument, where it is informally called the“lower white limestone” (Schneider, 1967; Rowley and others, in preparation),and about 30 feet (10 m) thick in the southern Red Hills (Threet, 1952).TcrRed member (Eocene and Paleocene) − Alternating beds of varicolored andcommonly mottled, pale-reddish-orange, reddish-brown, moderate-orange-pink,49