THE EVOLUTION OF THE ESTONIAN PRECAMBRIAN BASEMENT: GEOLOGICAL, GEOPHYSICAL AND GEOCHRONOLOGICAL CONSTRAINTS

Abstract

The Estonian Precambrian crystalline basement that consists of Paleo- to Meso-Proterozoic metamorphic and igneous rocks is covered by a 100-780 m thick deposit of Paleozoic sedimentary rocks. Thus, the basement is unavailable for direct surficial observations and our present knowledge is based on information from cores of deep drillings and interpretation of potential - gravity and magnetic - fields. Accordingly, the basement of Estonia is subdivided into two major geological units – North Estonian amphibolite and South Estonian granulite complexes. Further division includes six structural - petrological zones such as Tallinn, Alutaguse, Jõhvi, West-Estonian, Tapa and South-Estonian zones. The present article provides an updated overview of the Estonian Precambrian basement, its rock types, geophysical fields, geochronology, metamorphism and metallogenesis.

Keywords

• протерозой
• магматические и метаморфические породы
• геохронология
• геофизика
• металлогенез
• кристаллический фундамент эстонии