3-D thermal effect of late Cenozoic erosion and deposition within the Lofoten–Vesterålen segment of the Mid-Norwegian continental margin. Issue 2 (15th January 2018)

• Record Type: Journal Article
• Authors: Maystrenko, Yuriy Petrovich; Gernigon, Laurent; Olesen, Odleiv; Ottesen, Dag; Rise, Leif
• Is Part Of: Geophysical journal international. Volume 213:Issue 2(2018:May)
• Page Start: 885
• Page End: 918
• Publication Date: 2018-01-15
• Subjects: Heat flow -- Atlantic Ocean -- Europe -- Numerical modelling -- Continental margins: divergent -- Neotectonics -- Sedimentary basin processes; Geophysics -- Periodicals; 550
• DOI: 10.1093/gji/ggy013
• Languages: English
• ISSNs: 0956-540X

Abstract

Summary: A 3-D subsurface temperature distribution within the Lofoten–Vesterålen segment of the Mid-Norwegian continental margin and adjacent areas has been studied to understand the thermal effect of late Cenozoic erosion of old sedimentary and crystalline rocks and subsequent deposition of glacial sediments during the Pleistocene. A lithosphere-scale 3-D structural model of the Lofoten–Vesterålen area has been used as a realistic approximation of the geometries of the sedimentary infill, underlying crystalline crust and lithospheric mantle during the 3-D thermal modelling. The influence of late Cenozoic erosion and sedimentation has been included during the 3-D thermal calculations. In addition, the 3-D thermal modelling has been carried out by taking also into account the influence of early Cenozoic continental breakup. The results of the 3-D thermal modelling demonstrate that the mainland is generally colder than the basin areas within the upper part of the 3-D model. The thermal influence of the early Cenozoic breakup is still clearly recognizable within the western and deep parts of the Lofoten–Vesterålen margin segment in terms of the increased temperatures. The thermal effects of the erosion and deposition within the study area also indicate that a positive thermal anomaly exists within the specific subareas where sedimentary and crystalline rocks were eroded. A negative thermal effect occurs in the subareas affected by subsidence and sedimentation. The erosion-related positive thermal anomaly reaches its maximum of more than +27 °C at depths of 17–22 km beneath the eastern part of the Vestfjorden Basin. The most pronounced deposition-related negative anomaly shows a minimum of around −70 °C at 17–20 km depth beneath the Lofoten Basin. The second negative anomaly is located within the northeastern part of the Vøring Basin and has minimal values of around −48 °C at 12–14 km depth. These prominent thermal anomalies are associated with the subareas where relatively high erosional and depositional rates were observed for late Cenozoic time.