ANALYSIS OF BRITTLE PALEOGENE STRUCTURES IN THE SVEA REGION, EASTERN SPITSBERGEN, SVALBARD

The Svalbard Archipelago has been deformed by several tectonic events throughout its geologic history, most recently by rifting from Greenland during the Paleogene. Svalbard’s largest island, Spitsbergen, features two large-scale tectonic structures that formed during this Paleogene event: a fold-and-thrust belt along the west coast, and an associated foreland basin in the central part of the island. The largest coal mine on Spitsbergen, the Svea Nord mine, is located on the eastern edge of this foreland basin, in a region of subhorizontal sedimentary strata where small-scale brittle structures are observed. This study strives to determine whether these brittle structures are related to either 1) extension due to collapse of the over-thickened fold-and-thrust belt or 2) extensional forces resulting from the rifting of Svalbard and Greenland. Orientation data from faults, joints, and slickenlines were collected within the Svea Nord mine and the surrounding area in order to resolve the paleostress regime during deformation. Two groups of normal faults, S to SW dipping and NW dipping, were observed in the mine and the surrounding region. Joint orientation measurements show two dominant sub-vertical joint set orientations: ENE-WSW and NNW-SSE. Preliminary results from stress analysis of the joint sets show two distinct stress regimes with NW-SE and ENE-WSW σ₁ directions respectively. An analysis of lineaments from aerial imagery will help to solidify these initial findings.