Tertiary structures in the platform cover strata of Nordenskiöld Land, Svalbard

Abstract

Air photo interpretation along with limited field work is the basis of a compilation map of Tertiary structures in the Upper Paleozoic through Mesozoic platform cover strata of Nordenskiold Land. Permian Kapp Starostin Formation strata form a continuous marker horizon delineating both a large NE-verging fold complex, which involves the basement (Hecla Hoek sequence) through basal Tertiary strata, and somewhat smaller scale folds, some of which may have formed in association with detachments and thrusts within the platform cover sequence. The map pattern is both a function of local structural plunge and changes in fold geometry along strike. Regional considerations suggest that subsurface basement-involved thrusts exist. In S Nordenskiold Land, to the E of folded Kapp Starostin Formation strata, a 3.5 km wide zone of folding and thrusting in Triassic and Jurassic strata above a subhorizontal decollement is inferred to occur. Further E is the W limb of the central Tertiary basin syncline.