Changes in the Δ17O Values of Nitrate Contained in Sedimentary Strata of the Confidence Hills Formation to Mark Shifts in Precipitation over Time during the Pliocene-Pleistocene Transition

During the Pliocene-Pleistocene transition, the Earth went through significant changes. The Earth transitioned from a warm, relatively wet climate to a cooler and drier climate with the formation of ice caps. The goal of this project was to create a tool to be able to evaluate the ability of a paleo-climate model to predict changes in mean annual precipitation or determine what caused these changes. The main hypothesis was changes in the Δ17O values of nitrate contained in the sediments of the Confidence Hills formation would mark shifts in precipitation during the Pliocene-Pleistocene transition. The collected samples were crushed using a ball mill to grind the samples to a fine powder. The samples were mixed with Millipore® water and then sonicated and centrifuged, until the material was precipitated near the bottom of the tube. The mixture above the rock sample was vacuum filtered and diluted for ion chromatography analysis. This analysis was to be used to postulate conclusions.