Impact of Timanian faults on Arctic Tectonics

Description du projet

Comment les failles de Timanian influencent la tectonique de l’Arctique

Le projet ArcTec, financé par l’UE, se concentrera sur les failles WNW-ESE récemment identifiées dans le Svalbard et le nord de la mer de Barents en combinant des ensembles de données géophysiques, des travaux de terrain structuraux et sédimentologiques, ainsi que des analyses pétrologiques et géochronologiques. Des chercheurs canadiens, allemands et norvégiens étudieront l’étendue vers l’ouest, la cinématique et le moment de la formation, ainsi que la réactivation et la surimpression des failles de Timanian (vieilles d’environ 600 millions d’années) au cours des événements tectoniques ultérieurs dans l’Arctique. Ces failles seront ajoutées à un modèle d’évolution tectonique détaillé pour le Svalbard, le nord‑ouest de la mer de Barents et le détroit de Fram.

Objectif

ArcTec proposes to study (1) the westward extent, kinematics and timing of formation, and (2) reactivation–overprint of Timanian (i.e. ca. 600 million years old) faults during subsequent tectonic events in the Arctic, and to (3) insert these faults into a detailed tectonic evolution model for Svalbard, the northwestern Barents Sea and the Fram Strait. The project involves a collaboration between four researchers at UiO (Dr. Koehl and Dr. Anell), McGill University (Canada; Prof. Halverson), and BGR (Germany; Dr. Klitzke).
Thus far, remnants of Timanian metamorphism and basement were identified in southwestern (Majka et al., 2008) and northwestern Spitsbergen (Dallmeyer et al., 1990), and a regional (Torrelian) unconformity between Proterozoic and (latest Neoproterozoic–) lower Paleozoic metasedimentary rocks in southwestern and northeastern Spitsbergen, Bjørnøya and Nordaustlandet coeval with Timanian metamorphism suggests major tectonic reorganization occurred in the late Neoproterozoic (Horn and Orvin, 1928; Harland et al., 1992).
ArcTec will focus on newly identified WNW–ESE faults and basement heterogeneities in Svalbard and the northern Barents Sea, and combine geophysical (magnetic, gravimetric, bathymetric, seismic) datasets, structural and sedimentological fieldwork, and petrological and geochronological analyses to address the targeted objectives. ArcTec will investigate the impact of WNW–ESE faults on the exhumation–burial history of Svalbard and the northwestern Barents Sea margin, and their relationship with amphibolite facies metamorphism of Timanian age, with the Torrelian unconformity in southwestern and northeastern Spitsbergen and western Nordaustlandet, and with older (e.g. Grenvillian) and younger (e.g. Caledonian and Eurekan) structures and fabrics, such as crosscutting and controlling–controlled relationships (inheritance).