TY - CHAP A1 - Zeilinger, Gerold A1 - Mutti, Maria A1 - Strecker, Manfred A1 - Rehak, Katrin A1 - Bookhagen, Bodo A1 - Schwab, Marco T1 - Integration of digital elevation models and satellite images to investigate geological processes. N2 - In order to better understand the geological boundary conditions for ongoing or past surface processes geologists face two important questions: 1) How can we gain additional knowledge about geological processes by analyzing digital elevation models (DEM) and satellite images and 2) Do these efforts present a viable approach for more efficient research. Here, we will present case studies at a variety of scales and levels of resolution to illustrate how we can substantially complement and enhance classical geological approaches with remote sensing techniques. Commonly, satellite and DEM based studies are being used in a first step of assessing areas of geologic interest. While in the past the analysis of satellite imagery (e.g. Landsat TM) and aerial photographs was carried out to characterize the regional geologic characteristics, particularly structure and lithology, geologists have increasingly ventured into a process-oriented approach. This entails assessing structures and geomorphic features with a concept that includes active tectonics or tectonic activity on time scales relevant to humans. In addition, these efforts involve analyzing and quantifying the processes acting at the surface by integrating different remote sensing and topographic data (e.g. SRTM-DEM, SSM/I, GPS, Landsat 7 ETM, Aster, Ikonos…). A combined structural and geomorphic study in the hyperarid Atacama desert demonstrates the use of satellite and digital elevation data for assessing geological structures formed by long-term (millions of years) feedback mechanisms between erosion and crustal bending (Zeilinger et al., 2005). The medium-term change of landscapes during hundred thousands to millions years in a more humid setting is shown in an example from southern Chile. Based on an analysis of rivers/watersheds combined with landscapes parameterization by using digital elevation models, the geomorphic evolution and change in drainage pattern in the coastal Cordillera can be quantified and put into the context of seismotectonic segmentation of a tectonically active region. This has far-reaching implications for earthquake rupture scenarios and hazard mitigation (K. Rehak, see poster on IMAF Workshop). Two examples illustrate short-term processes on decadal, centennial and millennial time scales: One study uses orogen scale precipitation gradients derived from remotely sensed passive microwave data (Bookhagen et al., 2005a). They demonstrate how debris flows were triggered as a response of slopes to abnormally strong rainfall in the interior parts of the Himalaya during intensified monsoons. The area of the orogen that receives high amounts of precipitation during intensified monsoons also constitutes numerous landslide deposits of up to 1km3 volume that were generated during intensified monsoon phase at about 27 and 9 ka (Bookhagen et al., 2005b). Another project in the Swiss Alps compared sets of aerial photographs recorded in different years. By calculating high resolution surfaces the mass transport in a landslide could be reconstructed (M. Schwab, Universität Bern). All these examples, although representing only a short and limited selection of projects using remote sense data in geology, have as a common approach the goal to quantify geological processes. With increasing data resolution and new sensors future projects will even enable us to recognize more patterns and / or structures indicative of geological processes in tectonically active areas. This is crucial for the analysis of natural hazards like earthquakes, tsunamis and landslides, as well as those hazards that are related to climatic variability. The integration of remotely sensed data at different spatial and temporal scales with field observations becomes increasingly important. Many of presently highly populated places and increasingly utilized regions are subject to significant environmental pressure and often constitute areas of concentrated economic value. Combined remote sensing and ground-truthing in these regions is particularly important as geologic, seismicity and hydrologic data may be limited here due to the recency of infrastructural development. Monitoring ongoing processes and evaluating the remotely sensed data in terms of recurrence of events will greatly enhance our ability to assess and mitigate natural hazards.
Dokument 1: Foliensatz | Dokument 2: Abstract
Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung Workshop vom 9. - 10. Februar 2006 Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-7063 ER - TY - JOUR A1 - Ozsayin, Erman A1 - Ciner, T. Attila A1 - Rojay, F. Bora A1 - Dirik, R. Kadir A1 - Melnick, Daniel A1 - Fernandez-Blanco, David A1 - Bertotti, Giovanni A1 - Schildgen, Taylor F. A1 - Garcin, Yannick A1 - Strecker, Manfred A1 - Sudo, Masafumi T1 - Plio-Quaternary extensional tectonics of the Central Anatolian Plateau a case study from the Tuz Golu Basin, Turkey JF - Turkish journal of earth sciences = Türk yerbilimleri dergisi N2 - The Tuz Golu Basin is the largest sedimentary depression located at the center of the Central Anatolian Plateau, an extensive, low-relief region with elevations of ca. 1 km located between the Pontide and Tauride mountains. Presently, the basin morphology and sedimentation processes are mainly controlled by the extensional Tuz Golu Fault Zone in the east and the transtensional Inonu-Eskisehir Fault System in the west. The purpose of this study is to contribute to the understanding of the Plio-Quaternary deformation history and to refine the timing of the latest extensional phase of the Tuz Golu Basin. Field observations, kinematic analyses, interpretations of seismic reflection lines, and Ar-40/Ar-39 dating of a key ignimbrite layer suggest that a regional phase of NNW-SSE to NE-SW contraction ended by 6.81 +/- 0.24 Ma and was followed by N-S to NE-SW extension during the Pliocene-Quaternary periods. Based on sedimentological and chronostratigraphic markers, the average vertical displacement rates over the past 5 or 3 Ma with respect to the central part of Tuz Golu Lake are 0.03 to 0.05 mm/year for the fault system at the western flank of the basin and 0.08 to 0.13 mm/year at the eastern flank. Paleo-shorelines of the Tuz Golu Lake, vestiges of higher lake levels related to Quaternary climate change, are important strain markers and were formed during Last Glacial Maximum conditions as indicated by a radiocarbon age of 21.8 +/- 0.4 ka BP obtained from a stromatolitic crust. Geomorphic observations and deformed lacustrine shorelines suggest that the main strand of the Tuz Golu Fault Zone straddling the foothills of the Sereflikochisar-Aksaray range has not been active during the Holocene. Instead, deformation appears to have migrated towards the interior of the basin along an offshore fault that runs immediately west of Sereflikochisar Peninsula. This basinward migration of deformation is probably associated with various processes acting at the lithospheric scale, such as plateau uplift and/or microplate extrusion. KW - Central Anatolia KW - Tuz Golu Basin KW - orogenic plateau evolution KW - extensional tectonics KW - kinematic analysis KW - lake shoreline Y1 - 2013 U6 - https://doi.org/10.3906/yer-1210-5 SN - 1300-0985 VL - 22 IS - 5 SP - 691 EP - 714 PB - Tübitak CY - Ankara ER - TY - JOUR A1 - Ballato, Paolo A1 - Uba, Cornelius Eji A1 - Landgraf, Angela A1 - Strecker, Manfred A1 - Sudo, Masafumi A1 - Stockli, Daniel F. A1 - Friedrich, Anke M. A1 - Tabatabaei, Saeid H. T1 - Arabia-Eurasia continental collision insights from late Tertiary foreland-basin evolution in the Alborz Mountains, northern Iran JF - Geological Society of America bulletin N2 - A poorly understood lag time of 15-20 m.y. exists between the initial Arabia-Eurasia continental collision in late Eocene to early Oligocene time and the acceleration of tectonic and sedimentary processes across the collision zone in the early to late Miocene. The late Eocene to Miocene-Pliocene clastic and shallow-marine sedimentary rocks of the Kond, Eyvanekey, and Semnan Basins in the Alborz Mountains (northern Iran) offer the possibility to track the evolution of this orogen in the framework of collision processes. A transition from volcaniclastic submarine deposits to shallow-marine evaporites and terrestrial sediments occurred shortly after 36 Ma in association with reversals in sediment provenance, strata tilting, and erosional unroofing. These events followed the termination of subduction arc magmatism and marked a changeover from an extensional to a contractional regime in response to initiation of continental collision with the subduction of stretched Arabian lithosphere. This early stage of collision produced topographic relief associated with shallow foreland basins, suggesting that shortening and tectonic loading occurred at low rates. Starting from the early Miocene (17.5 Ma), flexural subsidence in response to foreland basin initiation occurred. Fast sediment accumulation rates and erosional unroofing trends point to acceleration of shortening by the early Miocene. We suggest that the lag time between the initiation of continental collision (36 Ma) and the acceleration of regional deformation (20-17.5 Ma) reflects a two-stage collision process, involving the "soft" collision of stretched lithosphere at first and "hard" collision following the arrival of unstretched Arabian continental litho sphere in the subduction zone. Y1 - 2011 U6 - https://doi.org/10.1130/B30091.1 SN - 0016-7606 VL - 123 IS - 1-2 SP - 106 EP - 131 PB - American Institute of Physics CY - Boulder ER - TY - JOUR A1 - Guzman, Silvina A1 - Strecker, Manfred A1 - Marti, Joan A1 - Petrinovic, Ivan A. A1 - Schildgen, Taylor F. A1 - Grosse, Pablo A1 - Montero-Lopez, Carolina A1 - Neri, Marco A1 - Carniel, Roberto A1 - D. Hongn, Fernando A1 - Muruaga, Claudia A1 - Sudo, Masafumi T1 - Construction and degradation of a broad volcanic massif: The Vicuna Pampa volcanic complex, southern Central Andes, NW Argentina JF - Geological Society of America bulletin N2 - The Vicuna Pampa volcanic complex, at the SE edge of the arid Puna Plateau of the Central Andes, records the interplay between volcanic construction and degra-dational processes. The low-sloping Vicuna Pampa volcanic complex, with a 1200-m-deep, southeastward-opening depression, was previously interpreted as a collapse caldera based on morphological considerations. However, characteristic features associated with collapse calderas do not exist, and close inspection instead suggests that the Vicuna Pampa volcanic complex is a strongly eroded, broad, massif-type composite volcano of mainly basaltic to trachyandesitic composition. Construction of the Vicuna Pampa volcanic complex occurred during two distinct cycles separated by the development of the depression. The first and main cycle took place at ca. 12 Ma and was dominated by lava flows and subordinate scoria cones and domes. The second cycle, possibly late Miocene in age, affected the SW portion of the depression with the emplacement of domes. We interpret the central depression as the result of a possible sector collapse and subsequent intense fluvial erosion during middle to late Miocene time, facilitated by faulting, steepened topography, and wetter climate conditions compared to today. We estimate that similar to 65% of the initial edifice of similar to 240 km(3) was degraded. The efficiency of degradation processes for removing mass from the Vicuna Pampa volcanic complex is surprising, considering that today the region is arid, and the stream channels within the complex are predominantly transport limited, forming a series of coalesced, aggraded alluvial fans and eolian infill. Hence, the Vicuna Pampa volcanic complex records the effects of past degradation efficiency that differs substantially from that of today. Y1 - 2017 U6 - https://doi.org/10.1130/B31631.1 SN - 0016-7606 SN - 1943-2674 VL - 129 SP - 750 EP - 766 PB - American Institute of Physics CY - Boulder ER - TY - JOUR A1 - Eugster, Patricia A1 - Thiede, Rasmus Christoph A1 - Scherler, Dirk A1 - Stübner, Konstanze A1 - Sobel, Edward A1 - Strecker, Manfred T1 - Segmentation of the Main Himalayan Thrust Revealed by Low-Temperature Thermochronometry in the Western Indian Himalaya JF - Tectonics N2 - Despite remarkable tectonostratigraphic similarities along the Himalayan arc, pronounced topographic and exhumational variability exists in different morphotectonic segments. The processes responsible for this segmentation are debated. Of particular interest is a 30- to 40-km-wide orogen-parallel belt of rapid exhumation that extends from central Nepal to the western Himalaya and its possible linkage to a midcrustal ramp in the basal decollement, and the related growth of Lesser Himalayan duplex structures. Here we present 26 new apatite fission track cooling ages from the Beas-Lahul region, at the transition from the Central to the Western Himalaya (77 degrees-78 degrees E) to investigate segmentation in the Himalayan arc from a thermochronologic perspective. Together with previously published data from this part of the orogen, we document significant lateral changes in exhumation between the Dhauladar Range to the west, the Beas-Lahul region, and the Sutlej area to the east of the study area. In contrast to the Himalayan front farther east, exhumation in the far western sectors is focused at the frontal parts of the mountain range and associated with the hanging wall of the Main Boundary Thrust fault ramp. Our results allow us to spatially correlate the termination of the rapid exhumation belt with a midcrustal ramp to the west. We suggest that a plunging anticline at the northwestern edge of the Larji-Kullu-Rampur window represents the termination of the Central Himalayan segment, which is related to the evolution of the Lesser Himalayan duplex. Key Points KW - exhumation KW - Himalaya KW - duplex KW - fission track thermochronology KW - MHT Y1 - 2018 U6 - https://doi.org/10.1029/2017TC004752 SN - 0278-7407 SN - 1944-9194 VL - 37 IS - 8 SP - 2710 EP - 2726 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Coutand, Isabelle A1 - Carrapa, Barbara A1 - Deeken, Anke A1 - Schmitt, Axel K. A1 - Sobel, Edward A1 - Strecker, Manfred T1 - Propagation of orographic barriers along an active range front : insights from sandstone petrography and detrital apatite fission-track thermochronology in the intramontane Angastaco basin, NW Argentina N2 - The arid Puna plateau of the southern Central Andes is characterized by Cenozoic distributed shortening forming intramontane basins that are disconnected from the humid foreland because of the defeat of orogen-traversing channels. Thick Tertiary and Quaternary sedimentary fills in Puna basins have reduced topographic contrasts between the compressional basins and ranges, leading to a typical low-relief plateau morphology. Structurally identical basins that are still externally drained straddle the eastern border of the Puna and document the eastward propagation of orographic barriers and ensuing aridification. One of them, the Angastaco basin, is transitional between the highly compartmentalized Puna highlands and the undeformed Andean foreland. Sandstone petrography, structural and stratigraphic analysis, combined with detrital apatite fission-track thermochronology from a similar to 6200-m-thick Miocene to Pliocene stratigraphic section in the Angastaco basin, document the late Eocene to late Pliocene exhumation history of source regions along the eastern border of the Puna (Eastern Cordillera (EC)) as well as the construction of orographic barriers along the southeastern flank of the Central Andes. Onset of exhumation of a source in the EC in late Eocene time as well as a rapid exhumation of the Sierra de Luracatao (in the EC) at about 20 Ma are recorded in the detrital sediments of the Angastaco basin. Sediment accumulation in the basin began similar to 15 Ma, a time at which the EC had already built sufficient topography to prevent Puna sourced detritus from reaching the basin. After similar to 13 Ma, shortening shifted eastward, exhuming ranges that preserve an apatite fission-track partial annealing zone recording cooling during the late Cretaceous rifting event. Facies changes and fossil content suggest that after 9 Ma, the EC constituted an effective orographic barrier that prevented moisture penetration into the plateau. Between 3.4 and 2.4 Ma, another orographic barrier was uplifted to the east, leading to further aridification and pronounced precipitation gradients along the mountain front. This study emphasizes the important role of tectonics in the evolution of climate in this part of the Andes Y1 - 2006 UR - http://www3.interscience.wiley.com/cgi-bin/issn?DESCRIPTOR=PRINTISSN&VALUE=0950-091X U6 - https://doi.org/10.1111/j.1365-2117.2006.00283.x SN - 0950-091X ER - TY - JOUR A1 - Parra, Mauricio A1 - Mora, Andrés A1 - Jaramillo, Carlos A1 - Strecker, Manfred A1 - Sobel, Edward A1 - Quiroz, Luis A1 - Rueda, Milton A1 - Torres, Vladimir T1 - Orogenic wedge advance in the northern Andes : evidence from the Oligocene-Miocene sedimentary record of the Medina Basin, Eastern Cordillera, Colombia N2 - Foreland basin development in the Andes of central Colombia has been suggested to have started in the Late Cretaceous through tectonic loading of the Central Cordillera. Eastward migration of the Cenozoic orogenic front has also been inferred from the foreland basin record west of the Eastern Cordillera. However, farther east, limited data provided by foreland basin strata and the adjacent Eastern Cordillera complicate any correlation among mountain building, exhumation, and foreland basin sedimentation. In this study, we present new data from the Medina Basin in the eastern foothills of the Eastern Cordillera of Colombia. We report sedimentological data and palynological ages that link an eastward-thinning early Oligocene to early Miocene syntectonic wedge containing rapid facies changes with an episode of fast tectonic subsidence starting at ca. 31 Ma. This record may represent the first evidence of topographic loading generated by slip along the principal basement-bounding thrusts in the Eastern Cordillera to the southwest of the basin. Zircon fission-track ages and paleo-current analysis reveal the location of these thrust loads and illustrate a time lag between the sedimentary signal of topographic loading and the timing of exhumation (ca. 18 Ma). This lag may reflect the period between the onset of range uplift and significant removal of overburden. Vitrinite reflectance data document northward along-strike propagation of the deformation front and folding of the Oligocene syntectonic wedge. This deformation was coupled with a nonuniform incorporation of the basin into the wedge-top depozone. Thus, our data set constitutes unique evidence for the early growth and propagation of the deformation front in the Eastern Cordillera, which may also improve our understanding of spatiotemporal patterns of foreland evolution in other mountain belts. Y1 - 2009 UR - http://gsabulletin.gsapubs.org/ U6 - https://doi.org/10.1130/B26257.1 SN - 0016-7606 ER - TY - JOUR A1 - Parra, Mauricio A1 - Mora, Andrés A1 - Sobel, Edward A1 - Strecker, Manfred A1 - González, Román T1 - Episodic orogenic front migration in the northern Andes : constraints from low-temperature thermochronology in the Eastern Cordillera, Colombia N2 - New thermochronometric data from the Eastern Cordillera of the Colombian Andes reveal diachronous exhumation associated with Cenozoic contractional deformation in this sector of the northern Andes. We present a comprehensive account of exhumation patterns along a 150-km-long, across-strike transect between similar to 4 degrees and 6 degrees N by integrating 29 new apatite fission track (AFT) ages and 17 new zircon fission track (ZFT) ages with sparse published thermochronological data from this area. Our data reveal episodic eastward migration of the orogenic front at an average rate of 2.5-2.7 mm/a during the Late Cretaceous-Cenozoic. We identify three major stages of orogen propagation: (1) slow propagation (0.5-3.1 mm/a) until early Eocene; (2) rapid orogenic advance (4.0-18.0 mm/a) during middle-late Eocene, which accounts for similar to 86% of the orogen's present width; and (3) slow orogen propagation (1.2-2.1 mm/a) from Oligocene to Holocene times. Our data demonstrate that in the course of changes in plate kinematics, the presence of inherited crustal anisotropies, such as the former rift-bounding faults of the Eastern Cordillera, favor a nonsystematic progression of foreland basin deformation through time by preferentially concentrating accommodation of slip and thrust loading along these zones of weakness. Y1 - 2009 UR - http://www.agu.org/journals/tc/ U6 - https://doi.org/10.1029/2008tc002423 SN - 0278-7407 ER - TY - JOUR A1 - Alonso, Ricardo N. A1 - Bookhagen, Bodo A1 - Carrapa, Barbara A1 - Coutand, Isabelle A1 - Haschke, Michael A1 - Hilley, George E. A1 - Schoenbohm, Lindsay M. A1 - Sobel, Edward A1 - Strecker, Manfred A1 - Trauth, Martin H. A1 - Villanueva, Arturo T1 - Tectonics, climate and landscape evolution of the Southern Central Andes : the Argentine Puna Plateau and adjacent regions between 22 and 30°S Y1 - 2006 SN - 978-3-540- 24329-8 ER - TY - JOUR A1 - Deeken, Anke A1 - Thiede, Rasmus Christoph A1 - Sobel, Edward A1 - Hourigan, J. K. A1 - Strecker, Manfred T1 - Exhumational variability within the Himalaya of northwest India JF - Earth & planetary science letters N2 - In the Himalaya of Chamba, NW India, a major orographic barrier in front of the Greater Himalayan Range extracts a high proportion of the monsoonal rainfall along its southern slopes and effectively shields the orogen interior from moisture-bearing winds. Along a similar to 100-km-long orogen perpendicular transect, 28 new apatite fission track (AFT) and 30 new zircon (U-Th)/He (ZHe) cooling ages reveal marked variations in age distributions and long-term exhumation rates between the humid frontal range and the semi-arid orogen interior. On the southern topographic front, very young, elevation-invariant AFT ages of <4 Ma have been obtained that are concentrated in a similar to 30-km-wide zone; 1-D-thermal modeling suggests a Plio-Pleistocene mean erosion rate of 0.8-1.9 mm yr(-1). In contrast, AFT and ZHe ages within the orogen interior are older (4-9 and 7-18 Ma, respectively), are positively correlated with sample elevation, and yield lower mean erosion rates (0.3-0.9 mm yr(-1)). Protracted low exhumation rates within the orogen interior over the last similar to 15 Myr prevailed contemporaneously with overall humid conditions and an effective erosional regime within the southern Himalaya. This suggests that the frontal Dhauladar Range was sufficiently high during this time to form an orographic barrier, focusing climatically enhanced erosional processes and tectonic deformation there. Thrusting along the two frontal range-bounding thrust, the Main Central Thrust and the Main Boundary Thrusts, was initiated at least similar to 15 Ma ago and has remained localized since then. The lack of evidence for localized uplift farther north indicates either a rather flat decollement with no ramp or the absence of active duplex systems beneath the interior of Chamba. Exhumational variability within Chamba is best explained as the result of continuous thrusting along a major basal decollement, with a flat beneath the slowly exhuming internal compartments and a steep frontal ramp at the rapidly exhuming frontal range. The pattern in Chamba contrasts with what is observed elsewhere along the Himalaya, where exhumation is focused in a zone similar to 150 km north of the orogenic front. In the NW Himalaya, preserved High Himalayan Crystalline nappes and Lesser Himalayan windows alternate on a relatively small scale of <100 km; these alternations are closely correlated with the pattern of exhumation. Although the spatial distribution of high-exhumation zones varies considerably between individual Himalayan sectors, all of these zones are closely correlated with locally higher rock-uplift rates, sharp topographic discontinuities, and focused orographic precipitation, suggesting strong feedbacks between tectonically driven rock uplift, orographically enhanced precipitation, and erosional processes. KW - apatite fission-track KW - zircon uranium-thorium-helium KW - thermochronology KW - exhumation KW - Himalaya KW - Haimantas Y1 - 2011 U6 - https://doi.org/10.1016/j.epsl.2011.02.045 SN - 0012-821X VL - 305 IS - 1-2 SP - 103 EP - 114 PB - Elsevier CY - Amsterdam ER -