Triassic Evolution of East Greenland

The Jameson Land Basin lies within the Greenland-Norway rift, to the south of Triassic basins on the Halten Bank and East Greenland shelf, and can therefore offer insights into the evolution of these less well documented offshore basins. Continental sedimentation, which persisted through the Mid Triassic into the Early Jurassic, was largely controlled by tectonic and climatic factors. These controls have important implications for hydrocarbon reservoir potential and source rock development and also for sediment delivery into the adjacent marine realm.

The Jameson Land Basin is orientated north-south, delineated by the Stauning Alper Fault to the west and the Liverpool Land high to the east. A total thickness of over 1.5 km of Mid to Late Triassic strata has been measured, predominantly comprising continental deposits laid down during arid to semi-arid climatic conditions. Initial Mid Triassic deposition comprises coarse clastic continental facies. These consist of alluvial sediments at their base (Pingo Dal Formation). They are overlain by a succession of fine grained gypsiferous lacustrine sediments (Gipsdalen Formation) which are in turn overlain by a succession of red mudstones with subordinate sandstones deposited in lacustrine and fluvial environments (Fleming Fjord Formation). The uppermost Triassic grades in to dark organic rich mudstones and buff coarse grained sandstones of lacustrine origin which belong to the Kap Stewart Group which straddles the Triassic – Jurassic boundary.

Lateral thickness variations have been identified within the basal coarse clastic portion of the Mid Triassic succession which provide evidence for syn-sedimentary faulting. Sites where syn-sedimentary faulting has been inferred have been examined more closely through geological mapping. More detailed sedimentological analysis has also been carried out through the upper, lacustrine portion of the succession to evaluate evidence for climatic trends. Macro palaeontological and palynological studies have allowed this work to be placed in the wider regional context of the North Atlantic rift system.

Within the framework documented here future work will include the first systematic study of hydrocarbon reservoir potential through the Triassic to Early Jurassic succession of East Greenland. This new study aims to assess reservoir potential and the controls thereon through this succession, which forms a key component of the Mesozoic basin fill.