VENDIAN VOLCANISM, WEATHERING, AND PHOSPHORUS CYCLE VARIATION IN THE EAST EUROPEAN PLATFORM

Abstract

Two geochemical types of volcanic ash are recognized in the Redkino Horizon of the East European Platform based on the systematics of trace elements. The first type developed in the northeastern area of the platform is characterized by Ni/Cr and Ce/Yb ratios typical of the silicic tephra of recent volcanic eruptions in the Kuril–Kamchatka and Aleutian island-arc systems. The respective ratios in ash of the second type are typical of volcanics from the lower Vendian Berestovets Formation. Depletion of the upper Vendian pelites of the East European Platform in Ca, Sr and P (relative to the PAAS) indicates the continental chemical weathering of provenance.