TY - JOUR A1 - Huelscher, Julian A1 - Sobel, Edward R. A1 - Verwater, Vincent A1 - Gross, Philip A1 - Chew, David A1 - Bernhardt, Anne T1 - Detrital apatite geochemistry and thermochronology from the Oligocene/Miocene Alpine foreland record the early exhumation of the Tauern Window JF - Basin research N2 - The early exhumation history of the Tauern Window in the European Eastern Alps and its surface expression is poorly dated and quantified, partly because thermochronological and provenance information are sparse from the Upper Austrian Northern Alpine Foreland Basin. For the first time, we combine a single-grain double-dating approach (Apatite Fission Track and U-Pb dating) with trace-element geochemistry analysis on the same apatites to reconstruct the provenance and exhumation history of the late Oligocene/early Miocene Eastern Alps. The results from 22 samples from the Chattian to Burdigalian sedimentary infill of the Upper Austrian Northern Alpine Foreland Basin were integrated with a 3D seismic-reflection data set and published stratigraphic reports. Our highly discriminative data set indicates an increasing proportion of apatites (from 6% to 23%) with Sr/Y values <0.1 up-section and an increasing amount of apatites (from 24% to 38%) containing >1,000 ppm light rare-earth elements from Chattian to Burdigalian time. The number of U-Pb ages with acceptable uncertainties increases from 40% to 59% up-section, with mostly late Variscan/Permian ages, while an increasing number of grains (10%-27%) have Eocene or younger apatite fission track cooling ages. The changes in the apatite trace-element geochemistry and U-Pb data mirror increased sediment input from an >= upper amphibolite-facies metamorphic source of late Variscan/Permian age - probably the otztal-Bundschuh nappe system - accompanied by increasing exhumation rates indicated by decreasing apatite fission track lag times. We attribute these changes to the surface response to upright folding and doming in the Penninic units of the future Tauern Window starting at 29-27 Ma. This early period of exhumation (0.3-0.6 mm/a) is triggered by early Adriatic indentation along the Giudicarie Fault System. KW - detrital apatite fission track analysis KW - detrital apatite trace-element KW - geochemistry KW - Molasse Basin KW - Northern Alpine Foreland Basin KW - Tauern KW - Window Y1 - 2021 U6 - https://doi.org/10.1111/bre.12593 SN - 0950-091X SN - 1365-2117 VL - 33 IS - 6 SP - 3021 EP - 3044 PB - Wiley-Blackwell CY - Oxford ER - TY - JOUR A1 - Bernhardt, Anne A1 - Stright, Lisa A1 - Lowe, Donald R. T1 - Channelized debris-flow deposits and their impact on turbidity currents: The Puchkirchen axial channel belt in the Austrian Molasse Basin JF - Sedimentology : the journal of the International Association of Sedimentologists N2 - Deposits of submarine debris flows can build up substantial topography on the sea floor. The resulting sea floor morphology can strongly influence the pathways of and deposition from subsequent turbidity currents. Map views of sea floor morphology are available for parts of the modern sea floor and from high-resolution seismic-reflection data. However, these data sets usually lack lithological information. In contrast, outcrops provide cross-sectional and lateral stratigraphic details of deep-water strata with superb lithological control but provide little information on sea floor morphology. Here, a methodology is presented that extracts fundamental lithological information from sediment core and well logs with a novel calibration between core, well-logs and seismic attributes within a large submarine axial channel belt in the Tertiary Molasse foreland basin, Austria. This channel belt was the course of multiple debris-flow and turbidity current events, and the fill consists of interbedded layers deposited by both of these processes. Using the core-well-seismic calibration, three-dimensional lithofacies proportion volumes were created. These volumes enable the interpretation of the three-dimensional distribution of the important lithofacies and thus the investigation of sea floor morphology produced by debris-flow events and its impact on succeeding turbidite deposition. These results show that the distribution of debris-flow deposits follows a relatively regular pattern of levees and lobes. When subsequent high-density turbidity currents encountered this mounded debris-flow topography, they slowed and deposited a portion of their sandy high-density loads just upstream of morphological highs. Understanding the depositional patterns of debris flows is key to understanding and predicting the location and character of associated sandstone accumulations. This detailed model of the filling style and the resulting stratigraphic architecture of a debris-flow dominated deep-marine depositional system can be used as an analogue for similar modern and ancient systems. KW - Basin axial submarine channel KW - debris-flow topography KW - deep-marine sedimentary processes KW - foreland basin KW - lithofacies proportion modeling KW - Molasse Basin KW - multi-attribute KW - multi-scale (MA-MS) proportion calibration KW - sea floor morphology KW - turbidites Y1 - 2012 U6 - https://doi.org/10.1111/j.1365-3091.2012.01334.x SN - 0037-0746 VL - 59 IS - 7 SP - 2042 EP - 2070 PB - Wiley-Blackwell CY - Hoboken ER -