@misc{SippelMeessenCacaceetal.2017, author = {Sippel, Judith and Meeßen, Christian and Cacace, Mauro and Mechie, James and Fishwick, Stewart and Heine, Christian and Scheck-Wenderoth, Magdalena and Strecker, Manfred}, title = {The Kenya rift revisited}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe}, number = {644}, issn = {1866-8372}, doi = {10.25932/publishup-41822}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-418221}, pages = {45 -- 81}, year = {2017}, abstract = {We present three-dimensional (3-D) models that describe the present-day thermal and rheological state of the lithosphere of the greater Kenya rift region aiming at a better understanding of the rift evolution, with a particular focus on plume-lithosphere interactions. The key methodology applied is the 3-D integration of diverse geological and geophysical observations using gravity modelling. Accordingly, the resulting lithospheric-scale 3-D density model is consistent with (i) reviewed descriptions of lithological variations in the sedimentary and volcanic cover, (ii) known trends in crust and mantle seismic velocities as revealed by seismic and seismological data and (iii) the observed gravity field. This data-based model is the first to image a 3-D density configuration of the crystalline crust for the entire region of Kenya and northern Tanzania. An upper and a basal crustal layer are differentiated, each composed of several domains of different average densities. We interpret these domains to trace back to the Precambrian terrane amalgamation associated with the East African Orogeny and to magmatic processes during Mesozoic and Cenozoic rifting phases. In combination with seismic velocities, the densities of these crustal domains indicate compositional differences. The derived lithological trends have been used to parameterise steady-state thermal and rheological models. These models indicate that crustal and mantle temperatures decrease from the Kenya rift in the west to eastern Kenya, while the integrated strength of the lithosphere increases. Thereby, the detailed strength configuration appears strongly controlled by the complex inherited crustal structure, which may have been decisive for the onset, localisation and propagation of rifting.}, language = {en} } @article{SippelMeessenCacaceetal.2017, author = {Sippel, Judith and Meessen, Christian and Cacace, Mauro and Mechie, James and Fishwick, Stewart and Heine, Christian and Scheck-Wenderoth, Magdalena and Strecker, Manfred}, title = {The Kenya rift revisited}, series = {Solid earth}, volume = {8}, journal = {Solid earth}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1869-9510}, doi = {10.5194/se-8-45-2017}, pages = {45 -- 81}, year = {2017}, abstract = {We present three-dimensional (3-D) models that describe the present-day thermal and rheological state of the lithosphere of the greater Kenya rift region aiming at a better understanding of the rift evolution, with a particular focus on plume-lithosphere interactions. The key methodology applied is the 3-D integration of diverse geological and geophysical observations using gravity modelling. Accordingly, the resulting lithospheric-scale 3-D density model is consistent with (i) reviewed descriptions of lithological variations in the sedimentary and volcanic cover, (ii) known trends in crust and mantle seismic velocities as revealed by seismic and seismological data and (iii) the observed gravity field. This data-based model is the first to image a 3-D density configuration of the crystalline crust for the entire region of Kenya and northern Tanzania. An upper and a basal crustal layer are differentiated, each composed of several domains of different average densities. We interpret these domains to trace back to the Precambrian terrane amalgamation associated with the East African Orogeny and to magmatic processes during Mesozoic and Cenozoic rifting phases. In combination with seismic velocities, the densities of these crustal domains indicate compositional differences. The derived lithological trends have been used to parameterise steady-state thermal and rheological models. These models indicate that crustal and mantle temperatures decrease from the Kenya rift in the west to eastern Kenya, while the integrated strength of the lithosphere increases. Thereby, the detailed strength configuration appears strongly controlled by the complex inherited crustal structure, which may have been decisive for the onset, localisation and propagation of rifting.}, language = {en} } @article{MeessenSippelScheckWenderothetal.2018, author = {Meessen, Christian and Sippel, Judith and Scheck-Wenderoth, Magdalena and Heine, C. and Strecker, Manfred}, title = {Crustal structure of the andean foreland in Northern Argentina}, series = {Journal of geophysical research : Solid earth}, volume = {123}, journal = {Journal of geophysical research : Solid earth}, number = {2}, publisher = {American Geophysical Union}, address = {Washington}, issn = {2169-9313}, doi = {10.1002/2017JB014296}, pages = {1875 -- 1903}, year = {2018}, abstract = {Previous thermomechanical modeling studies indicated that variations in the temperature and strength of the crystalline crust might be responsible for the juxtaposition of domains with thin-skinned and thick-skinned crustal deformation along strike the foreland of the central Andes. However, there is no evidence supporting this hypothesis from data-integrative models. We aim to derive the density structure of the lithosphere by means of integrated 3-D density modeling, in order to provide a new basis for discussions of compositional variations within the crust and for future thermal and rheological modeling studies. Therefore, we utilize available geological and geophysical data to obtain a structural and density model of the uppermost 200km of the Earth. The derived model is consistent with the observed Bouguer gravity field. Our results indicate that the crystalline crust in northern Argentina can be represented by a lighter upper crust (2,800kg/m(3)) and a denser lower crust (3,100kg/m(3)). We find new evidence for high bulk crustal densities >3,000kg/m(3) in the northern Pampia terrane. These could originate from subducted Puncoviscana wackes or pelites that ponded to the base of the crystalline crust in the late Proterozoic or indicate increasing bulk content of mafic material. The precise composition of the northern foreland crust, whether mafic or felsic, has significant implications for further thermomechanical models and the rheological behavior of the lithosphere. A detailed sensitivity analysis of the input parameters indicates that the model results are robust with respect to the given uncertainties of the input data.}, language = {en} } @misc{GholamrezaieScheckWenderothSippeletal.2018, author = {Gholamrezaie, Ershad and Scheck-Wenderoth, Magdalena and Sippel, Judith and Strecker, Manfred}, title = {Variability of the geothermal gradient across two differently aged magma-rich continental rifted margins of the Atlantic Ocean}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-409493}, pages = {19}, year = {2018}, abstract = {Abstract. The aim of this study is to investigate the shallow thermal field differences for two differently aged passive continental margins by analyzing regional variations in geothermal gradient and exploring the controlling factors for these variations. Hence, we analyzed two previously published 3-D conductive and lithospheric-scale thermal models of the Southwest African and the Norwegian passive margins. These 3-D models differentiate various sedimentary, crustal, and mantle units and integrate different geophysical data such as seismic observations and the gravity field. We extracted the temperature-depth distributions in 1 km intervals down to 6 km below the upper thermal boundary condition. The geothermal gradient was then calculated for these intervals between the upper thermal boundary condition and the respective depth levels (1, 2, 3, 4, 5, and 6 km below the upper thermal boundary condition). According to our results, the geothermal gradient decreases with increasing depth and shows varying lateral trends and values for these two different margins. We compare the 3-D geological structural models and the geothermal gradient variations for both thermal models and show how radiogenic heat production, sediment insulating effect, and thermal lithosphere-asthenosphere boundary (LAB) depth influence the shallow thermal field pattern. The results indicate an ongoing process of oceanic mantle cooling at the young Norwegian margin compared with the old SW African passive margin that seems to be thermally equilibrated in the present day.}, language = {en} } @article{ScheckWenderothCacaceMaystrenkoetal.2014, author = {Scheck-Wenderoth, Magdalena and Cacace, Mauro and Maystrenko, Yuriy Petrovich and Cherubini, Yvonne and Noack, Vera and Kaiser, Bjoern Onno and Sippel, Judith and Bjoern, Lewerenz}, title = {Models of heat transport in the Central European Basin System: Effective mechanisms at different scales}, series = {Marine and petroleum geology}, volume = {55}, journal = {Marine and petroleum geology}, publisher = {Elsevier}, address = {Oxford}, issn = {0264-8172}, doi = {10.1016/j.marpetgeo.2014.03.009}, pages = {315 -- 331}, year = {2014}, abstract = {Understanding heat transport in sedimentary basins requires an assessment of the regional 3D heat distribution and of the main physical mechanisms responsible for the transport of heat. We review results from different 3D numerical simulations of heat transport based on 3D basin models of the Central European Basin System (CEBS). Therefore we compare differently detailed 3D structural models of the area, previously published individually, to assess the influence of (1) different configurations of the deeper lithosphere, (2) the mechanism of heat transport considered and (3) large faults dissecting the sedimentary succession on the resulting thermal field and groundwater flow. Based on this comparison we propose a modelling strategy linking the regional and lithosphere-scale to the sub-basin and basin-fill scale and appropriately considering the effective heat transport processes. We find that conduction as the dominant mechanism of heat transport in sedimentary basins is controlled by the distribution of thermal conductivities, compositional and thickness variations of both the conductive and radiogenic crystalline crust as well as the insulating sediments and by variations in the depth to the thermal lithosphere-asthenosphere boundary. Variations of these factors cause thermal anomalies of specific wavelength and must be accounted for in regional thermal studies. In addition advective heat transport also exerts control on the thermal field on the regional scale. In contrast, convective heat transport and heat transport along faults is only locally important and needs to be considered for exploration on the reservoir scale. The general applicability of the proposed workflow makes it of interest for a broad range of application in geosciences including oil and gas exploration, geothermal utilization or carbon capture and sequestration issues. (C) 2014 Elsevier Ltd. All rights reserved.}, language = {en} } @article{GholamrezaieScheckWenderothSippeletal.2018, author = {Gholamrezaie, Ershad and Scheck-Wenderoth, Magdalena and Sippel, Judith and Strecker, Manfred}, title = {Variability of the geothermal gradient across two differently aged magma-rich continental rifted margins of the Atlantic Ocean}, series = {Solid Earth}, volume = {9}, journal = {Solid Earth}, number = {1}, publisher = {Copernicus}, address = {G{\"o}ttingen}, issn = {1869-9529}, doi = {10.5194/se-9-139-2018}, pages = {139 -- 158}, year = {2018}, abstract = {Abstract. The aim of this study is to investigate the shallow thermal field differences for two differently aged passive continental margins by analyzing regional variations in geothermal gradient and exploring the controlling factors for these variations. Hence, we analyzed two previously published 3-D conductive and lithospheric-scale thermal models of the Southwest African and the Norwegian passive margins. These 3-D models differentiate various sedimentary, crustal, and mantle units and integrate different geophysical data such as seismic observations and the gravity field. We extracted the temperature-depth distributions in 1 km intervals down to 6 km below the upper thermal boundary condition. The geothermal gradient was then calculated for these intervals between the upper thermal boundary condition and the respective depth levels (1, 2, 3, 4, 5, and 6 km below the upper thermal boundary condition). According to our results, the geothermal gradient decreases with increasing depth and shows varying lateral trends and values for these two different margins. We compare the 3-D geological structural models and the geothermal gradient variations for both thermal models and show how radiogenic heat production, sediment insulating effect, and thermal lithosphere-asthenosphere boundary (LAB) depth influence the shallow thermal field pattern. The results indicate an ongoing process of oceanic mantle cooling at the young Norwegian margin compared with the old SW African passive margin that seems to be thermally equilibrated in the present day.}, language = {en} } @misc{GholamrezaieScheckWenderothSippeletal.2018, author = {Gholamrezaie, Ershad and Scheck-Wenderoth, Magdalena and Sippel, Judith and Strecker, Manfred}, title = {Variability of the geothermal gradient across two differently aged magma-rich continental rifted margins of the Atlantic Ocean}, series = {Postprints der Universit{\"a}t Potsadm : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsadm : Mathematisch-Naturwissenschaftliche Reihe}, number = {621}, issn = {1866-8372}, doi = {10.25932/publishup-41821}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-418210}, pages = {20}, year = {2018}, abstract = {The aim of this study is to investigate the shal- low thermal field differences for two differently aged pas- sive continental margins by analyzing regional variations in geothermal gradient and exploring the controlling factors for these variations. Hence, we analyzed two previously pub- lished 3-D conductive and lithospheric-scale thermal models of the Southwest African and the Norwegian passive mar- gins. These 3-D models differentiate various sedimentary, crustal, and mantle units and integrate different geophysi- cal data such as seismic observations and the gravity field. We extracted the temperature-depth distributions in 1 km intervals down to 6 km below the upper thermal boundary condition. The geothermal gradient was then calculated for these intervals between the upper thermal boundary condi- tion and the respective depth levels (1, 2, 3, 4, 5, and 6 km below the upper thermal boundary condition). According to our results, the geothermal gradient decreases with increas- ing depth and shows varying lateral trends and values for these two different margins. We compare the 3-D geologi- cal structural models and the geothermal gradient variations for both thermal models and show how radiogenic heat pro- duction, sediment insulating effect, and thermal lithosphere- asthenosphere boundary (LAB) depth influence the shallow thermal field pattern. The results indicate an ongoing process of oceanic mantle cooling at the young Norwegian margin compared with the old SW African passive margin that seems to be thermally equilibrated in the present day.}, language = {en} }