Lidites of the North Onegian Synclinorium of Karelia, Their Trace Element Composition and Possible Genesis

Abstract

We studied of Paleoproterozoic siliceous rocks (lidites) geochemistry from the North-Onegian synclinorium (Karelia). The objects of research are represented by 16 samples of lidites selected from one stratigraphic level in geological sections of two sites – Tetyugino and Shunga. Their structural characteristics and mineral composition features were studied using a scanning electron microscope with an energy-dispersion microanalyzer. The trace elements were determined by the inductively coupled plasma mass spectrometric method (ICP MS). Tetyugino lidites contain biophilic elements (P, Co, Cu, Mo, V, Ba) predominantly, while Shunga lidites ‒ lithophilic elements (Li, Rb, Cs). The trace element composition of lidites indicates that their formation took place on the periphery of the hydrothermal system, while the Tetyugino site was closer to the place of hydrothermal discharge than Shunga. The peculiarities of the lidites chemical composition allow us to consider them as raw materials for very pure quartz.