TERTIARY OR CRETACEOUS AGE FOR SPITSBERGENS FOLD-THRUST BELT ON THE BARENTS SHELF

Several publications propose that main-phase fold-thrust development o n Spitsbergen was Late Cretaceous and not Tertiary as previously thoug ht. The question of timing is crucial to models for crustal response t o transpressive plate motions. Involvement of Tertiary strata in fold- thrust structures, the sedimentology of the Tertiary basin strata, and studies of paleo-stress field evolution all indicate Paleocene to Eoc ene fold-thrust development during opening of the Norwegian-Greenland oceanic basin. A regional angular unconformity of < 1 degrees between Paleocene and Early Cretaceous strata is consistently disconformable t o the eye and precludes any significant older deformation in the immed iate area preunconformity deformation was likely strike slip in charac ter and concentrated in the west. The proposal for Late Cretaceous fol d-thrust belt formation is inconsistent with the geology.