TY - JOUR A1 - Stright, Lisa A1 - Bernhardt, Anne A1 - Boucher, Alexandre T1 - DFTopoSim modeling topographically-controlled deposition of subseismic scale sandstone packages within a mass transport dominated deep-water channel belt JF - Mathematical geosciences : the official journal of the International Association for Mathematical Geosciences N2 - Facies bodies in geostatistical models of deep-water depositional environments generally represent channel-levee-overbank-lobe morphologies. Such models adequately capture one set of the erosional and depositional processes resulting from turbidity currents traveling downslope to the ocean basin floor. However, depositional morphologies diverge from the straight forward channel-levee-overbank-lobe paradigm when the topography of the slope or the shape of the basin impacts the timing and magnitude of turbidity current deposition. Subaqueous mass-transport-deposits (MTDs) present the need for an exception to the channel-levee-overbank-lobe archetype. Irregular surface topography of subaqueous MTDs can play a primary role in controlling sand deposition from turbidity currents. MTD topography creates mini-basins in which sand accumulates in irregularly-shaped deposits. These accumulations are difficult to laterally correlate using well-log data due to their variable and unpredictable shape and size. Prediction is further complicated because sandstone bodies typical of this setting are difficult to resolve in seismic-reflection data. An event-based model is presented, called DFTopoSim, which simulates debris flows and turbidity currents. The accommodation space on top of and between debris flow lobes is filled in by sand from turbidity currents. When applied to a subsurface case in the Molasse Basin of Upper Austria, DFTopoSim predicts sand packages consistent with observations from core, well, and seismic data and the interpretation of the sedimentologic processes. DFTopoSim expands the set of available geostatistical deep-water depositional models beyond the standard channel-levee-overbank-lobe model. KW - Geostatistics KW - Event-based modeling KW - Facies modeling KW - Deep-marine sedimentology KW - Submarine channel Y1 - 2013 U6 - https://doi.org/10.1007/s11004-013-9444-7 SN - 1874-8961 VL - 45 IS - 3 SP - 277 EP - 296 PB - Springer CY - Heidelberg 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 -