Seminar

Magnesium is the third most abundant lithophile element in earth and the second most abundant cation element in the ocean. High precision Mg isotopes analytical method was established in the last decade and Mg isotope has been brought into a spot on geochemical studies. Previous studies have proven large equilibrium Mg isotopes fractionation can occur even at high temperature systems such as in coexisting minerals of igneous rocks. Much larger Mg isotopic fractionation should be recorded in low temperature samples and thus Mg isotope should be a promising geochemical tracer in various low temperature geological processes.

In this study, to our knowledge, we first report the Mg isotope composition of a sequence of natural evaporite samples. We measure the δ26MgDSM3 of three langbeinite samples of Salado Formation, southeastern New Mexico, USA, and discuss the variation in δ26Mg values and their implications for prediction on the depositional environment for these evaporites. We also want to monitor the δ26Mg of pore fluids of marine sediments and nearby estuary river sediments in order to monitor the possible Mg sinks in the marine sediments columns and the seawater Mg contents over time.