Depositional environment and source rock potential of Miocene strata from the central Fram Strait: introduction of a new computing tool for simulating organic facies variations

Organic-rich sediments were recognized in early Miocene strata from the Norwegian-Greenland Sea during ODP Leg 151. Three organic-geochemical subunits were distinguished in Hole 909C using detailed organic-geochemical and microscopic analyses. TOC (up to 3 wt%), HI (up to 200 mg HC/g TOC), and delta C-13(org) values (similar to24-26parts per thousand) indicate the predominance of terrestrial type Ill organic matter in Subunit 3 (similar to18-16.2 Ma). Biomarker and vitrinite reflectance values (R(0)similar to0.5%) point to rather fresh immature terrestrial organic matter supplied by river discharge from adjacent vegetated coastal areas. Although the sediments of Subunit 3 have a fair (to good) source rock potential they are insufficiently mature to generate significant amounts of oil or gas. To test if the moderate generation potential and source rock quality of Subunit 3 are applicable to the entire area, the computer software OF-Mod was applied. Several modelling runs testing the most probable depositional scenarios result, even under conservative assumptions, in the formation of good to excellent source rocks towards the basin margins. (C) 2002 Elsevier Science Ltd. All rights reserved.