DETAILED GEOLOGIC MAPS OF THE LANE MOUNTAIN AREA NORTH CENTRAL MOJAVE DESERT, CALOFORNIA PART 1: THE NEED FOR NEW MAPPING

Enigmatic rocks in the Lane Mountain area north of Barstow California have long intrigued geologists. The Lane Mountain 15' quad was mapped by McCulloh in the 1950es and published in 1960. McCulloh recognized several sequences of metasedimentary rocks of assumed Paleozoic and Mesozoic age, Mesozoic plutonic rocks and Tertiary volcanic rocks. McCulloh's mapping was small scale and does not display detailed stratigraphic or structural data. More recent synthesis presentations all refer to McCulloh's mapping, but there are no new maps of the Lane Mountain area. The geology of the area is referenced many times, but no new mapping of the Lane Mountain area has been done for 60 years.

Regional synthesis during the 1980es recognized that Paleozoic metasedimentary rocks north of Lane Mountain differ from shallow water cratonal-miogeoclinal Paleozoic sedimentary sequences present in the Mojave region. Cambrian thru Ordovician deep water Paleozoic rocks correlated with rocks of the Antler orogenic belt in central Nevada were recognized. An overlap sequence of Mississippian synorogenic rocks deposited on top of the older deep water rocks was recognized, as were off shore deposits of Pennsylvanian and Permian age deposited on the older overlap and deepwater sediments (Carr and others 1981, Carr and others 1992, Carr and others 1997) in the El Paso Mountains and several other ranges and have been called the "Northwest Mojave Terrane". Post orogenic sediments of Mesozoic age are postulated to have been deposited on the exposed and eroded older rocks.

New detailed geologic mapping in the Lane Mountain area within the context of modern regional framework, allows more accurate correlation of strata, and a more clear and complete geologic picture. Old 15' maps have been replaced with 7.5' quads, and Google Earth air photos allow good resolution. GPS allows more accurate locations. Mapping at 1:6,000 scale allowed complex structures to be depicted and resolved. The mapped area covers portions of the Lane Mountain, Williams Well and Coyote Lake 7.5' quads. The large scale detailed mapping clarifies and resolves complex Paleozoic and Mesozoic stratigraphic and structural relationships within the various tectono-stratigraphic sequences exposed in the Lane Mountain area within the context of prevailing regional framework.