Regional development and sequence stratigraphy of the Middle to Late Triassic Snadd Formation, Norwegian Barents Sea

The Middle to Late Triassic Snadd Formation represents one of the later stages of Early Mesozoic infilling of the Barents Sea Basin, expressed by a silicilastic wedge prograding from the southeast, where sediments were shed from the Uralide Orogeny. The formation was deposited in a shallow (100-500 m) basin facing the Boreal part of the Panthalassa Ocean, and the progradation reached its peak at the Svalbard Archipelago which has since been uplifted and where outcrops are exposed as the time-equivalent Botneheia and De Geerdalen formations. The Snadd Formation includes depositional environments ranging from offshore shale through shallow marine to fluvial, arranged in discrete stratigraphic sequences. Here we present a refined sequence stratigraphic framework for the Snadd Formation. Two second order sequences have been interpreted within the limits of the study area, divided into six third order sequences. The two second order sequences are split along an Intra Carnian maximum flooding surface. Depositional elements inherent to the sequence stratigraphic framework are also interpreted and extrapolated so as to describe the regional distribution of potential reservoir sandstones and the control exerted on the development of third order sequences. Different depositional environments from various datasets and scales of observation show the progressive development of a prograding delta across more than 700 km from a proximal position on the Finnmark Platform to a distal position on Edgeoya. Regional correlation of well logs and 2D seismic coupled with detailed depositional environment interpretation from 3D seismic and core has resulted in basin-wide palaeogeographic reconstruction of the formation throughout the Norwegian part of the Barents Sea, with implications for understanding the distribution and evolution of depositional systems during this large-scale basin infill. (C) 2015 Elsevier Ltd. All rights reserved.