Down Lake Mead Staircase to the Permian Fit 3 of 3

Walk up Lovell Wash and getting older as I go... after the shakeup... along the Vegas Shear Zone 14-8 million years BC. The Las Vegas shear zone has offset the predominantly north-south trending mountain ranges of southern Nevada, bending them into large oroflexes. The shearing transported and upended this tectonic block containing layers of the Jurassic to the Permian 170 - 250 Ma made up of sand dunes, lakes, and ocean bottoms.

Free USGS Geologic Map of Callville Bay Quad:
https://pubs.nbmg.unr.edu/Geologic-Callville-Bay-quad-p/m139.htm

Trs Red sandstone unit (Miocene). Basin-fill clastic and evaporitic rocks, chiefly sandstone, siltstone, gravel, gypsiferous sandstone and mudstone, and gypsum. Air-fall ash from within 50 m of the base of the red sandstone unit yielded an age of 11.10+-0.08 Ma and interpreted the depositional setting as primarily basinal (mainly playa) with local fault-front alluvial fan lithofacies.

Thb Bitter Ridge Limestone Member Horse Spring Formation (Middle Miocene). Mostly pale yellowish-brown to pale yellowish-gray stromatolitic lacustrine limestone. Limestone is crystalline and porous with bedsets typically 15 to 80 cm thick containing wavy internal continuous to discontinuous laminations. Fission-track age of 13.0 +-0.8 Ma for overlying Lovell Wash Member.

Thtc Conglomerate lithofacies Thumb member (Middle Miocene). Mostly pinkish-gray to grayish-pink; where content of Mesozoic rock is high, pale red to pale reddish-brown. Polymictic with angular to rounded clasts ranging to boulders and blocks in some beds and consisting primarily of clasts of gray Paleozoic carbonate rocks. 13.2 or 17.2 Ma.

Ja Aztec Sandstone (Lower Jurassic). Sandunes of 170 Ma?

Jkm Kayenta and Moenave Formations undifferentiated (Lower Jurassic) 200 Ma. Consists mostly of brick red,
lenticular- to flat-bedded, fine-grained sandstone enclosed in minor flat-bedded red siltstone and shale.

Trc Chinle Formation (Upper Triassic) 230 Ma Sandstone, siltstone, claystone, conglomerate, arenaceous limestone and limestone of mixed fluvial, paludal, and fluviolacustrine deposition.

Trm Moenkopi Formation (Middle? and Lower Triassic) Continental clastic and evaporite strata and marine limestone divided into four members following Stewart and others (1972), from top down: upper red member, Shnabkaib Member, Virgin Limestone Member, and lower red member.

Pk Kaibab Formation (Lower Permian) 250 Ma Divided into Harrisburg and Fossil Mountain Members following subdivisions adapted by Cheevers and Rawson (1979) and Nielson (1981).

Las Vegas Shear Zone Info:
https://pubs.geoscienceworld.org/gsa/gsabulletin/article-abstract/85/6/985/201680/Measure-and-Date-of-Movement-on-Las-Vegas-Valley?redirectedFrom=PDF

Youtube Music:
Sam Cooke
https://www.youtube.com/watch?v=hFgdVUP46ik
Taking Heads
https://www.youtube.com/watch?v=WYFqdrOMqk4