Estimating Pre-Rift Bedrock Geology Under Shelf Sediments of the Circumpolar Arctic

Abstract

In the Arctic Ocean, almost 50% of the seafloor is underlain by continental shelf. However, the geology of the pre-rift continental crust that makes up the basement of the shelf is poorly constrained because it is overlain by thick Cenozoic sedimentary cover. This study explores the available data and methods for mapping the continental bedrock geology beneath the sediments. In a GIS framework, extrapolation of geological map units to the shelf edge was guided by onshore structure and offshore bathymetry. The compilation involved identification of data sources, development of a common legend for pre-rift basement geology, building attributes tables for analysis, and extrapolating geological contacts. As a first-order assessment of mineral resource potential of the continental shelf, permissive tracts for certain mineral deposit types were also identified. The analysis includes a case study of permissive geology for magmatic Ni-Cu deposits in the Taimyr Peninsula in northern Russia.