DETAILED GEOLOGIC MAPS OF THE NORTHERN CALICO MOUNTAINS AND THE LANE MOUNTAIN AREA, CENTRAL MOJAVE DESERT CALIFORNIA: PART 2 STRATIGRAPHY AND STRUCTURE OF PALEOZOIC, MESOZOIC AND CENOZOIC ROCKS

Detailed geologic mapping of the North Calico Mountains and Lane Mountain area (1:6,000 scale) north of Barstow CA resolves complex stratigraphy and structure of enigmatic metasedimentary rocks. Paleozoic and Mesozoic (?) strata are exposed in three blocks. Most contacts are west verging thrust faults. The south block exposes >30,000 feet (tectonic thickness) of east dipping tectonically juxtaposed Paleozoic rocks. Structurally lowest meta-andesite is overlain by impure quartzite and argillite of slope and basin affinity, overlain by mixed siliciclastic and carbonate off shore and shallow water miogeoclinal carbonate strata of Permian age, tectonically overlain by meta-andesite, turbidites (impure quartzite), overlain by off shore and shallow water vitreous quartzite, mixed siliciclastic non carbonate and impure carbonate strata.

The same strata are exposed in the central and north blocks but are more metamorphosed, deformed, folded, attenuated or with thousands of feet of strata missing. Correlation with central and northern blocks shows up to 15,000 feet of strata are missing. Chert conglomerate/breccia in the southern block may be Mississippian overlap. or submarine slide onto older deep water sediments. Overlying allochthonous rocks in the central and southern blocks resemble miogeoclinal Paleozoic carbonates of the Cambrian Bonanza King Formation, Mississippian Monte Cristo Limestone and Pennsylvanian Bird Spring Formation and may have been emplaced as backslides onto the previously juxtaposed deeper water rocks. Calc hornfels and conglomerate in the central block strongly resembles Jurassic Fairview Valley Formation. McCulloh recovered a Mesozoic fossil from these rocks. Miocene volcanic, sedimentary and intrusive rocks (Lane Mtn. Volcanics, Jackhammer and Pickhandle Formations), were deposited in synextensional supradetachment basins related to the central Mojave core complex. Miocene rocks are complexly faulted, including reverse faults, strike slip and normal faults. Pickhandle rocks are locally intensely folded adjacent to intrusive dacite sills and dikes. The new mapping indicates Paleozoic, Mesozoic and Cenozoic rocks in the north Calico Mountains and Lane Mountain can be correlated in the context of prevailing regional tectono-stratigraphic framework.