Tracing extreme events off Taiwan using microfossils

The assemblage of calcite shell-bearing benthic foraminifera in marine sediments is influenced by environmental parameters such as food and oxygen availability. Therefore, there is no surprise that you tend to find different species of benthic foraminifera at shallow vs deep water environment. Species that live in coral reef for example cannot survive in deep water environment at thousands of meters water depth. The presence of the calcite shells of shallow water species in deep sea sediment cores means that these shells must have been transported laterally to the deeper environment. Similarly, planktic foraminiferal abundance in marine sediments also tells us something about the depositional environment, as its abundance is typically lower in shallow water environment. These two pieces of evidence can thus be used to trace lateral transport of sediments off Taiwan, which may occur during extreme events like earthquakes or typhoons.