Cal Poly Geology Club Death Valley Field Trip – 2004

Noble to the extent that he identified it as his Amargosa thrust (nowdiscredited).The pale gray to dark lavender, fault-bounded lenses at the base of theoverlying chaos consist of arkosic sandstone and siltstone of the dominantlyclastic lower portion of the Crystal Spring. The dark green lenses higher on theface are slices of the diabase sill that separates the clastic members from thered-brown carbonate member. The ridge-former at the crest of the hill is theyellowish gray dolomite of the Noonday Dolomite. Strata of the JohnnieFormation are exposed on the south side of the hill crest. Both the Noonday andJohnnie occur as fault-bounded lenses and thus also qualify as chaotic.177.5(17.7) Intersection with CA 127, turn right (south) to Shoshone.179.0 (1.5) Downtown Shoshone, END of Day 1.MileageDeath Valley Field Trip Road Log – Day 20.0 Day 2 begins at the junction of the Charlie Brown Highway (CA 178) and CA127 just south of Shoshone. Head west on CA 178.3.9 (3.9) Charlie Brown Highway road cut (STOP 1).This is one of the more famousroadcuts in California geology. Itexposes not only a spectacularexample of the interior of a weldedtuff, with a layer of remelted obsidian,but also a normal fault that has beenphotographed for many basic geologytexts. The fault cuts Miocene tuff andvolcaniclastic deposits. The darkbrown layer in the footwall rocks is aconglomerate. A prominent blackband just to the left of this photo is awelded tuff comprised of volcanicglass and flattened pumice fragments.Return to vehicles, turn around and head back west to CA 127.7.8 (3.9) Turn left (south) on CA 127.13.0 (5.2) Turn left on the Tecopa Hot Springs Road.