Jurassic history and stratigraphy of Colorado

Page 80

46 The thin limestone lenses occasionally found mittent lakes of limited size and dur atd.on, in desert The country. of occurrence probably· represent inter­ such with the eolian theory of Cross-bedding - Gypsum Valley, Uravan, direction required to obtain narrow Wild Bill all Canyon, "Navajo in Colorado Canyon, Maverick Canyon, yield of the unit with reliable resultant dip. a a high consistency only 50 readings Figure 23 78 E. to S. 18 E. and indicates range from S. The Navajo appears to northwest quadrant. forming natural contour around the a stUdies of the The very consistent northwest wind rapid study a -- and Summit direction. permits by Baker (1946, p.6S) key localities These localities source as deposition. sandstone have been made at five factor for such The evidence in Colorado is also in agreement Cross-stratification (see Fig. 23). encountered are wind-polished pebbls noted in the Vernal section and those described substantiates this. as a shows the source in the feather out to the east periphery of the then topograph­ ically prominent Uncompahgre Range. Physiographic expression country" generally weatQers in cross-bedding is ings rising above is chara.cterized water to the during Nugget the by as The Navajo sandstone rounded domes long benches of numerous pot holes occasional rain storms. the deposits which the usually form underlying formations. a It of 'Itanks" which fill with The same sandstone in the northwestern thick correlative on "Navajo domes and massives build­ great man-made of of the turrets or Its outcrops by erosion. etched out picturesque landscape - characteristics part of northeastern Utah. apply of Colorado and the