Pre-Paleozoic weathering crust on the southeastern coast of the Kanin Peninsula

Abstract

Introduction: the Kanin Peninsula, which is a continuation of the Timan structures, has a similar geological structure and history of development. The weathering crusts, with which numerous deposits of ore and non-metallic minerals are associated in Timan, remain practically unexplored on the Kanin Peninsula. Geochemical study of weathering crusts – promising objects for searching for clay raw materials and placer deposits – is the basis for correlating paleontologically uncharacterized deposits, conducting paleogeographic and paleogeodynamic reconstructions, and clarifying the history of development and sedimentation patterns of a poorly studied region.

Methodology: in order to establish the compositional features and genetic affiliation of the developed at the contact rocks of the Riphean basement and Paleozoic deposits, clay formations of the weathering crust, described and tested in the bedrock outcrop on the sea coast of the Kanin Peninsula, a study was conducted of the composition of petrogenic oxides, rare earth elements and clay minerals.

Results and discussion: interpretation of the results of chemical analyses and the features of the distribution of REE and the phase composition of the clay fraction allowed us to conclude that the studied formations differ from the original rocks in the ratio of rock-forming elements, the content and composition of micaceous minerals and represent unmetamorphosed eluvium on the substrate of ancient highly hydrolyzed metaterrigenous rocks.

Conclusion: the studied clay formations of the pre-Paleozoic weathering crust are diagnosed as rocks of the zone of lightening and mechanical disintegration, and the weathering crust belongs to the hydromica-kaolinite type of the siallitic stage.