Taphonomy and depositional circumstances of exceptionally preserved fossils from the Kinzers Formation (Cambrian), southeastern Pennsylvania

The Emigsville Member of the Kinzers Formation (Cambrian), southeastern Pennsylvania, is a deposit of exceptional preservation containing three main lithofacies that were part of a mixed siliciclastic-carbonate debris fan developed seaward of a carbonate shelf along the Appalachian Margin of Laurentia. Fossils were exceptionally preserved in a shelf environment subject to tempestite deposition. Most remains are fragmentary, which emphasizes the importance of predation as a taphonomic process where Emigsville sediments were deposited. Remains are preserved mostly as organic carbon films, pyrite crusts, and aluminosilicate films. These preservation styles apparently depended upon the development of microbial consortia in isolated microenvironments, and some of the microbes were autolithified. ntary and biological evidence suggests that anoxia, salinity fluctuations, and sedimentary obrution played relatively minor roles in the Emigsville Member of the Kinzers Formation. The abundance of exceptionally preserved remains suggests that exceptional sedimentary conditions were not necessary in the Cambrian in order for exceptional preservation to occur. The abundance of predation evidence in a deposit of exceptional preservation reinforces the concept that predation was the primary taphonomic filter during Cambrian time.