THE MIDDLE TO LATE PERMIAN TRANSITION IN THE CACHE CREEK TERRANE OF BRITISH COLUMBIA, CANADA

The Cache Creek Terrane of British Columbia offers a unique opportunity to study deep-sea sediments from the Late Permian, something rarely seen elsewhere in the world as subduction has consumed most of the deep-sea floor. The Middle Permian through Triassic Porcupine Creek section offers a chance to supplement our knowledge of shelf conditions with data from the open ocean, which has not been studied to the same extent as other Permian sediments elsewhere in the world. Middle Permian strata are represented in this section by by recrystallized mudstones contain fusilinids, transitioning into argillaceous cherts. This transition is likely to represent the Middle-Late Permian (Guadalupian-Lopingian) boundary in this setting. This transition from the Guadalupian to the Lopingian epochs represents a time of high environmental stress, and can be viewed as a precursor to the end-Permian mass extinction. In this study, we use geochemical indicators to reconstruct environmental fluctuations prior to and during the Guadalupian-Lopingian boundary (GLB). Understanding the conditions at the time of deposition will help us to better understand how latest Guadalupian environmental disruptions affected environments in the Panthalassic Ocean. To accomplish this study, we spent one week collecting samples and logging lithostratigraphic sections in the Marble Range of central British Columbia. A total of 22 samples were collected from two sections below the Permian - Triassic boundary in a portion of the Porcupine Creek section. This transition from carbonate to chert around the G-L boundary may indicate a shift away from the deposition of carbonate as marine invertebrates suffered from the end-Guadalupian extinction. Thus, through this research, we hope to deepen our understanding of this volatile period in Earth history.