Red Hill I forms the northern end of the Northern Simpson Park Range, northwest of Eureka, Nevada. The Red Hill I locality (lowest part of Red Hill section II in Murphy et al. 1976, Red Hill I of Gregory et al. 1977) lies near the exposed bottom of a sequence of reddish, yellow and greenish gray silty lime mudstones, approximately 80 m thick, at the base of the southwest flank of Red Hill (NW ,...