Subsidence, rapid inversion, and slow erosion of the Central Tertiary Basin of Svalbard: Evidence from the thermal evolution and basin modeling
N. Dörr, F. Lisker, M. Jochmann, T. Rainer, A. Schlegel, K. Schubert, C. Spiegel, "Subsidence, rapid inversion, and slow erosion of the Central Tertiary Basin of Svalbard: Evidence from the thermal evolution and basin modeling", Circum-Arctic Structural Events: Tectonic Evolution of the Arctic Margins and Trans-Arctic Links with Adjacent Orogens, Karsten Piepjohn, Justin V. Strauss, Lutz Reinhardt, William C. McClelland
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The Central Tertiary Basin (CTB) of Svalbard provides a rare opportunity for studying the sedimentary response to the Cenozoic evolution of the Barents Sea area. Here we present a basin model based on low-temperature thermochronology data, vitrinite reflectance measurements, and clay mineralogy from two drill cores inside the CTB. Our model suggests a tight relationship between the basin history and the regional geodynamic evolution. Enhanced heat flow during the Paleocene implies an extensional or transtensional origin of the basin, prior to Eurekan deformation. The first, compressional stage of the Eurekan orogeny was associated with rapid basin subsidence and high deposition rates, causing the coalification of the CTB hard coals. The second, transpressional stage of the Eurekan triggered rapid basin erosion and was associated with a decreasing heat flow. Onset of erosion is placed at ~45 ± 5 Ma, suggesting cessation of CTB deposition already by the late Early Eocene. Rapid erosion stopped coevally or just prior to the change to an extensional setting at the end of Eurekan deformation. Between ~40 and 10 Ma, the CTB experienced continuous slow erosion. From the Late Miocene onwards, erosion again accelerated, maybe related to lithospheric processes associated with northward propagation of the Knipovich Ridge. Estimates from our best-fit model suggest that nearly ~4 km of overburden was removed from the CTB since the end of Early Eocene.