STRATIGRAPHIC INTERPRETATION OF THE TRANSITION FROM THE PRECAMBRIAN STERLING QUARTZITE TO LOWER WOOD CANYON FORMATION, EMIGRANT PASS, CALIFORNIA

Ediacaran fossils record the development of complex biota preceding the Cambrian explosion. Remnants of these organisms are documented in the Ediacaran strata exposed in Newfoundland, Namibia, China, and California and represent some of the first forms of multicellular life on Earth. Ediacaran fossils have been found in several localities around the Death Valley region of California, specifically within the White, Nopah, and Grapevine mountain ranges. In the southern localities, the Sterling Quartzite (SQ) - Lower Wood Canyon Formation (LWC) transition often coincides with occurrences of Ediacaran fauna.The focus of this study is to document detailed sedimentary features and stratigraphic relationships found within a new section located in the Emigrant Pass area of Inyo County, California. The Emigrant Pass section contains a variety of trace fossils including tubular, intersecting, cylindrical traces and a continuous microbial algal mat bed (Kinneyia) exposed within the lower part of the LWC. Possible resting traces, impressions, toolmarks, gas escape structures, scratch circles, and flat pebble conglomerates are also present within this transitional sequence. Thin sections of these features were made to interpret their structure and composition. Initial description and measurement of the section show three parasequences marked by distinct carbonate ledges within the LWC, facilitating correlation to other Sterling-Lower Wood Canyon sections in the Death Valley area. Interpretation of this stratigraphic sequence is significant in understanding environmental changes related to this important time interval in Earth’s history.