EFFECTS OF BACKGROUND VOLCANISM ON AN EARLY JURASSIC CORAL REEF

The end-Triassic mass extinction nearly caused the demise of coral reef ecosystems. During this time period and into the Early Jurassic, coral-sponge reef building collapsed, and reefs were globally rare. However, reef-building corals survived into the Early Jurassic in a few locations. The Telkwa reef, located in the Telkwa range of British Columbia, Canada, is a notably well preserved example of an Early Jurassic reef. This reef was located in the low- to mid-latitude Panthalassic Ocean, and is now part of the Stikine Terrane. The reef’s proximity to the greater Stikine volcanic arc meant that its period of growth was punctuated by several periods of volcanism. The Telkwa reef is especially valuable because it can provide insight into coral recovery following the end-Triassic mass extinction.

In this study, we reconstruct the volcanic history of the Telkwa reef. By isolating background volcanism signals in sediment flanking the reef, the reef environment itself can be better understood. This will be achieved by using geochemical data derived from X-Ray Fluorescence spectroscopy (XRF), isotopic geochemistry, and petrographic analysis of thin section slides. Isolating the background volcanism and coming to understand the volcanic history of the reef is paramount to understanding what environmental conditions allowed to reef to be ecologically successful despite the global biotic crisis. The Telkwa reef’s survival story not only allows for a greater understanding of coral recovery and the evolution of modern-style reef building, but may also offer insight into how modern coral may respond to the present-day coral crisis.