TY - JOUR A1 - Cohen, Andrew A1 - Campisano, C. A1 - Arrowsmith, J. Ramón A1 - Asrat, Asfawossen A1 - Behrensmeyer, A. K. A1 - Deino, A. A1 - Feibel, C. A1 - Hill, A. A1 - Johnson, R. A1 - Kingston, J. A1 - Lamb, Henry F. A1 - Lowenstein, T. A1 - Noren, A. A1 - Olago, D. A1 - Owen, R. B. A1 - Potts, R. A1 - Reed, Kate A1 - Renaut, R. A1 - Schäbitz, Frank A1 - Tiercelin, J. -J. A1 - Trauth, Martin H. A1 - Wynn, J. A1 - Ivory, S. A1 - Brady, K. A1 - Rodysill, J. A1 - Githiri, J. A1 - Russell, J. A1 - Förster, Verena A1 - Dommain, René A1 - Rucina, S. A1 - Deocampo, D. A1 - Russell, J. A1 - Billingsley, A. A1 - Beck, C. A1 - Dorenbeck, G. A1 - Dullo, L. A1 - Feary, D. A1 - Garello, D. A1 - Gromig, R. A1 - Johnson, T. A1 - Junginger, A. A1 - Karanja, M. A1 - Kimburi, E. A1 - Mbuthia, A. A1 - McCartney, T. A1 - McNulty, E. A1 - Muiruri, V. A1 - Nambiro, E. A1 - Negash, E. W. A1 - Njagi, D. A1 - Wilson, J. N. A1 - Rabideaux, N. A1 - Raub, T. A1 - Sier, M. J. A1 - Smith, P. A1 - Urban, J. A1 - Warren, M. A1 - Yadeta, M. A1 - Yost, C. A1 - Zinaye, B. T1 - The Hominin Sites and Paleolakes Drilling Project: inferring the environmental context of human evolution from eastern African rift lake deposits JF - Scientific Drilling N2 - The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to where fossil hominins (ancestors or close relatives of modern humans) are found, or from the study of deep sea drill cores. However, outcrop sediments are often highly weathered and thus are unsuitable for some types of paleoclimatic records, and deep sea core records come from long distances away from the actual fossil and stone tool remains. The Hominin Sites and Paleolakes Drilling Project (HSPDP) was developed to address these issues. The project has focused its efforts on the eastern African Rift Valley, where much of the evidence for early hominins has been recovered. We have collected about 2 km of sediment drill core from six basins in Kenya and Ethiopia, in lake deposits immediately adjacent to important fossil hominin and archaeological sites. Collectively these cores cover in time many of the key transitions and critical intervals in human evolutionary history over the last 4 Ma, such as the earliest stone tools, the origin of our own genus Homo, and the earliest anatomically modern Homo sapiens. Here we document the initial field, physical property, and core description results of the 2012-2014 HSPDP coring campaign. Y1 - 2016 U6 - https://doi.org/10.5194/sd-21-1-2016 SN - 1816-8957 SN - 1816-3459 VL - 21 SP - 1 EP - 16 PB - Copernicus CY - Göttingen ER - TY - GEN A1 - Cohen, Abby A1 - Campisano, Christopher A1 - Arrowsmith, J. Ramon A1 - Asrat, Asfawossen A1 - Behrensmeyer, A. K. A1 - Deino, A. A1 - Feibel, C. A1 - Hill, A. A1 - Johnson, R. A1 - Kingston, J. A1 - Lamb, Henry F. A1 - Lowenstein, T. A1 - Noren, A. A1 - Olago, D. A1 - Owen, Richard Bernhart A1 - Potts, R. A1 - Reed, Kate A1 - Renaut, R. A1 - Schäbitz, F. A1 - Tiercelin, J.-J. A1 - Trauth, Martin H. A1 - Wynn, J. A1 - Ivory, S. A1 - Brady, K. A1 - O’Grady, R. A1 - Rodysill, J. A1 - Githiri, J. A1 - Russell, Joellen A1 - Foerster, Verena A1 - Dommain, René A1 - Rucina, J. S. A1 - Deocampo, D. A1 - Russell, J. A1 - Billingsley, A. A1 - Beck, C. A1 - Dorenbeck, G. A1 - Dullo, L. A1 - Feary, D. A1 - Garello, D. A1 - Gromig, R. A1 - Johnson, T. A1 - Junginger, Annett A1 - Karanja, M. A1 - Kimburi, E. A1 - Mbuthia, A. A1 - McCartney, Tannis A1 - McNulty, E. A1 - Muiruri, V. A1 - Nambiro, E. A1 - Negash, E. W. A1 - Njagi, D. A1 - Wilson, J. N. A1 - Rabideaux, N. A1 - Raub, Timothy A1 - Sier, Mark Jan A1 - Smith, P. A1 - Urban, J. A1 - Warren, M. A1 - Yadeta, M. A1 - Yost, Chad A1 - Zinaye, B. T1 - The Hominin Sites and Paleolakes Drilling Project BT - inferring the environmental context of human evolution from eastern African rift lake deposits T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to where fossil hominins (ancestors or close relatives of modern humans) are found, or from the study of deep sea drill cores. However, outcrop sediments are often highly weathered and thus are unsuitable for some types of paleoclimatic records, and deep sea core records come from long distances away from the actual fossil and stone tool remains. The Hominin Sites and Paleolakes Drilling Project (HSPDP) was developed to address these issues. The project has focused its efforts on the eastern African Rift Valley, where much of the evidence for early hominins has been recovered. We have collected about 2 km of sediment drill core from six basins in Kenya and Ethiopia, in lake deposits immediately adjacent to important fossil hominin and archaeological sites. Collectively these cores cover in time many of the key transitions and critical intervals in human evolutionary history over the last 4 Ma, such as the earliest stone tools, the origin of our own genus Homo, and the earliest anatomically modern Homo sapiens. Here we document the initial field, physical property, and core description results of the 2012-2014 HSPDP coring campaign. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 611 KW - Turkana-Basin KW - Adar formation KW - climate-change KW - olorgesailie formation KW - Southern Ethiopia KW - global climate KW - Kenya Rift KW - Pleistocene KW - variability KW - patterns Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-412498 IS - 611 ER - TY - JOUR A1 - Arrowsmith, J. Ramon A1 - Crosby, Christopher J. A1 - Korzhenkov, Andrey M. A1 - Mamyrov, Ernest A1 - Povolotskaya, Irina A1 - Guralnik, Benny A1 - Landgraf, Angela T1 - Surface rupture of the 1911 Kebin (Chon-Kemin) earthquake, Northern Tien Shan, Kyrgyzstan JF - Seismicity, fault rupture and earthquake hazards in slowly deforming regions N2 - The 1911 Chon-Kemin (Kebin) earthquake culminated c. 30 years of remarkable earthquakes in the northern Tien Shan (Kyrgyzstan and Kazakhstan). Building on prior mapping of the event, we traced its rupture in the field and measured more than 50 offset landforms. Cumulative fault rupture length is >155-195 km along 13 fault patches comprising six sections. The patches are separated by changes of dip magnitude or dip direction, or by 4-10 km-wide stepovers. One <40 km section overlaps and is parallel to the main north-dipping rupture but is 7 km north and dips opposite (south). Both ends of the rupture are along mountain front thrust faults demonstrating late Quaternary activity. We computed the moment from each fault patch using the surface fault traces, dip inferred from the traces, 20 km seismogenic thickness, rigidity of 3.3 x 10(10) N m(-2) and dip slip converted from our observations of the largely reverse sense of motion vertical offsets. The discontinuous patches with c. 3-4 m average slip and peak slip of <14 m yield a seismic moment of 4.6 x 10(20) Nm (M-w 7.78) to 7.4 x 10(20) Nm (M-w 7.91). The majority of moment was released along the inner eastern rupture segments. This geological moment is lower by a factor of 1.5 from that determined from teleseismic data. Y1 - 2016 SN - 978-1-86239-745-3 SN - 978-1-86239-964-8 U6 - https://doi.org/10.1144/SP432.10 SN - 0305-8719 VL - 432 SP - 233 EP - 253 PB - The Geological Society CY - London ER - TY - JOUR A1 - Arrowsmith, J. Ramón A1 - Strecker, Manfred T1 - Seismotectonic range-front segmentation and mountain-belt growth in the Pamir-Alai region, Kyrgyzstan (India- Eurasia collision zone) Y1 - 1999 ER - TY - GEN A1 - Braun, David R. A1 - Aldeias, Vera A1 - Archer, Will A1 - Arrowsmith, J. Ramon A1 - Baraki, Niguss A1 - Campisano, Christopher J. A1 - Deino, Alan L. A1 - DiMaggio, Erin N. A1 - Dupont-Nivet, Guillaume A1 - Engda, Blade A1 - Feary, David A. A1 - Garello, Dominique I. A1 - Kerfelew, Zenash A1 - McPherron, Shannon P. A1 - Patterson, David B. A1 - Reeves, Jonathan S. A1 - Thompson, Jessica C. A1 - Reed, Kaye E. T1 - Reply to Sahle and Gossa: Technology and geochronology at the earliest known Oldowan site at Ledi-Geraru, Ethiopia T2 - Proceedings of the National Academy of Sciences of the United States of America Y1 - 2019 U6 - https://doi.org/10.1073/pnas.1911952116 SN - 0027-8424 N1 - Letter VL - 116 IS - 41 SP - 20261 EP - 20262 PB - National Acad. of Sciences CY - Washington ER - TY - JOUR A1 - Landgraf, Angela A1 - Dzhumabaeva, A. A1 - Abdrakhmatov, Kanatbek E. A1 - Strecker, Manfred A1 - Macaulay, E. A. A1 - Arrowsmith, J. Ramón A1 - Sudhaus, Henriette A1 - Preusser, F. A1 - Rugel, Georg A1 - Merchel, Silke T1 - Repeated large-magnitude earthquakes in a tectonically active, low-strain continental interior: The northern Tien Shan, Kyrgyzstan JF - Journal of geophysical research : Solid earth N2 - The northern Tien Shan of Kyrgyzstan and Kazakhstan has been affected by a series of major earthquakes in the late 19th and early 20th centuries. To assess the significance of such a pulse of strain release in a continental interior, it is important to analyze and quantify strain release over multiple time scales. We have undertaken paleoseismological investigations at two geomorphically distinct sites (Panfilovkoe and Rot Front) near the Kyrgyz capital Bishkek. Although located near the historic epicenters, both sites were not affected by these earthquakes. Trenching was accompanied by dating stratigraphy and offset surfaces using luminescence, radiocarbon, and Be-10 terrestrial cosmogenic nuclide methods. At Rot Front, trenching of a small scarp did not reveal evidence for surface rupture during the last 5000 years. The scarp rather resembles an extensive debris-flow lobe. At Panfilovkoe, we estimate a Late Pleistocene minimum slip rate of 0.2 +/- 0.1 mm/a, averaged over at least two, probably three earthquake cycles. Dip-slip reverse motion along segmented, moderately steep faults resulted in hanging wall collapse scarps during different events. The most recent earthquake occurred around 3.6 +/- 1.3 kyr ago (1 sigma), with dip-slip offsets between 1.2 and 1.4 m. We calculate a probabilistic paleomagnitude to be between 6.7 and 7.2, which is in agreement with regional data from the Kyrgyz range. The morphotectonic signals in the northern Tien Shan are a prime example of deformation in a tectonically active intracontinental mountain belt and as such can help understand the longer-term coevolution of topography and seismogenic processes in similar structural settings worldwide. Y1 - 2016 U6 - https://doi.org/10.1002/2015JB012714 SN - 2169-9313 SN - 2169-9356 VL - 121 SP - 3888 EP - 3910 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Patyniak, Magda A1 - Landgraf, Angela A1 - Dzhumabaeva, Atyrgul A1 - Abdrakhmatov, Kanatbek E. A1 - Rosenwinkel, Swenja A1 - Korup, Oliver A1 - Preusser, Frank A1 - Fohlmeister, Jens Bernd A1 - Arrowsmith, J. Ramon A1 - Strecker, Manfred T1 - Paleoseismic Record of Three Holocene Earthquakes Rupturing the Issyk-Ata Fault near Bishkek, North Kyrgyzstan JF - Bulletin of the Seismological Society of America N2 - The northern edge of the western central Tien Shan range is bounded by the Issyk-Ata fault situated south of Bishkek, the capital of Kyrgyzstan. Contraction in this thick-skinned orogen occurs with low-strain accumulation and long earthquake recurrence intervals. In the nineteenth to twentieth centuries, a sequence of large earthquakes with magnitudes between 6.9 and 8 affected the northern Tien Shan but left nearly the entire extent of the Issyk-Ata fault unruptured. Here, the only known historic earthquake ruptured in A.D. 1885 (M6.9) along the western end of the Issyk-Ata fault. Because earthquakes in low-strain regions often tend to cluster in time and may promote failure along nearby structures, the earthquake history of the northern Tien Shan represents an exceptional structural setting for studying fault behavior affected by an intraplate earthquake sequence. We present a paleoseismological study from one site (Belek) along the Issyk-Ata fault located east of the A.D. 1885 epicentral area. Our analysis combines a range of tools, including photogrammetry, differential Global Positioning System, 3D visualization, and age modeling with different dating methods (infrared stimulated luminescence, radiocarbon, U-series) to improve the reliability of an event chronology for the trench stratigraphy and fault geometry. We were able to distinguish three different surfacerupturing paleoearthquakes; these affected the area before 10.5 +/- 1.1 cal ka B.P., at similar to 5.6 +/- 1.0 cal ka B.P., and at similar to 630 +/- 100 cal B.P., respectively. Associated paleomagnitudes for the last two earthquakes range between M6.7 and 7.4, with a cumulative slip rate of 0.7 +/- 0.32 mm/yr. We did not find evidence for the A.D. 1885 event at Belek. Our study yielded two main overall results: first, it extends the regional historic and paleoseismic record; second, the documented rupture events along the Issyk-Ata fault suggest that this fault was not affected in its entirety; instead, these events indicate segmented rupture behavior. Y1 - 2017 U6 - https://doi.org/10.1785/0120170083 SN - 0037-1106 SN - 1943-3573 VL - 107 SP - 2721 EP - 2737 PB - Seismological Society of America CY - Albany ER - TY - JOUR A1 - Toke, Nathan A. A1 - Arrowsmith, J. Ramon A1 - Rymer, Michael J. A1 - Landgraf, Angela A1 - Haddad, David E. A1 - Busch, Melanie A1 - Coyan, Joshua A1 - Hannah, Alexander T1 - Late Holocene slip rate of the San Andreas fault and its accommodation by creep and moderate-magnitude earthquakes at Parkfield, California JF - Geology N2 - Investigation of a right-laterally offset channel at the Miller's Field paleoseismic site yields a late Holocene slip rate of 26.2 +6.4/-4.3 mm/yr (1 sigma) for the main trace of the San Andreas fault at Parkfield, California. This is the first well-documented geologic slip rate between the Carrizo and creeping sections of the San Andreas fault. This rate is lower than Holocene measurements along the Carrizo Plain and rates implied by far-field geodetic measurements (similar to 35 mm/yr). However, the rate is consistent with historical slip rates, measured to the northwest, along the creeping section of the San Andreas fault (<30 mm/yr). The paleoseismic exposures at the Miller's Field site reveal a pervasive fabric of clay shear bands, oriented clockwise oblique to the San Andreas fault strike and extending into the uppermost stratigraphy. This fabric is consistent with dextral aseismic creep and observations of surface slip from the 28 September 2004 M6 Parkfield earthquake. Together, this slip rate and deformation fabric suggest that the historically observed San Andreas fault slip behavior along the Parkfield section has persisted for at least a millennium, and that significant slip is accommodated by structures in a zone beyond the main San Andreas fault trace. Y1 - 2011 U6 - https://doi.org/10.1130/G31498.1 SN - 0091-7613 VL - 39 IS - 3 SP - 243 EP - 246 PB - American Institute of Physics CY - Boulder ER - TY - JOUR A1 - Thiede, Rasmus Christoph A1 - Arrowsmith, J. Ramón A1 - Bookhagen, Bodo A1 - McWilliams, Michael O. A1 - Sobel, Edward A1 - Strecker, Manfred T1 - From tectonically to erosionally controlled development of the Himalayan orogen N2 - Whether variations in the spatial distribution of erosion influence the location, style, and magnitude of deformation within the Himalayan orogen is a matter of debate. We report new Ar-40/Ar-39 white mica and apatite fission- track (AFT) ages that measure the vertical component of exhumation rates along an similar to 120-km-wide NE-SW transect spanning the greater Sutlej region of northwest India. The Ar-40/Ar-39 data indicate that first the High Himalayan Crystalline units cooled below their closing temperature during the early to middle Miocene. Subsequently, Lesser Himalayan Crystalline nappes cooled rapidly, indicating southward propagation of the orogen during late Miocene to Pliocene time. The AFT data, in contrast, imply synchronous exhumation of a NE-SW-oriented similar to 80 x 40 km region spanning both crystalline nappes during the Pliocene-Quaternary. The locus of pronounced exhumation defined by the AFT data correlates with a region of high precipitation, discharge, and sediment flux rates during the Holocene. This correlation suggests that although tectonic processes exerted the dominant control on the denudation pattern before and until the middle Miocene; erosion may have been the most important factor since the Pliocene Y1 - 2005 SN - 0091-7613 ER - TY - JOUR A1 - Haddad, David E. A1 - Zielke, Olaf A1 - Arrowsmith, J. Ramon A1 - Purvance, Matthew D. A1 - Haddad, Amanda G. A1 - Landgraf, Angela T1 - Estimating two-dimensional static stabilities and geomorphic settings of precariously balanced rocks from unconstrained digital photographs JF - Geosphere N2 - The need to accurately document the spatiotemporal distribution of earthquake-generated strong ground motions is essential for evaluating the seismic vulnerability of sites of critical infrastructure. Understanding the threshold for maximum earthquake-induced ground motions at such sites provides valuable information to seismologists, earthquake engineers, local agencies, and policymakers when determining ground motion hazards of seismically sensitive infrastructures. In this context, fragile geologic features such as precariously balanced rocks (PBRs) serve as negative evidence for earthquake-induced ground motions and provide important physical constraints on the upper limits of ground motions. The three-dimensional (3D) shape of a PBR is a critical factor in determining its static stability and thus susceptibility to toppling during strong ground shaking events. Furthermore, the geomorphic settings of PBRs provide important controls on PBR exhumation histories that are interpreted from surface exposure dating methods. In this paper, we present PBRslenderness, a MATLAB-based program that evaluates the two-dimensional (2D) static stabilities of PBRs from unconstrained digital photographs. The program's graphical user interface allows users to interactively digitize a PBR and calculates the 2D geometric parameters that define its static stability. A reproducibility study showed that our 2D calculations compare well against their counterparts that were computed in 3D (R-2 = 0.77-0.98 for 22 samples). A sensitivity study for single-user and multiuser digitization routines further confirmed the reproducibility of PBRslenderness estimates (coefficients of variation c(v) = 4.3%-6.5% for 100 runs; R-2 = 0.87-0.99 for 20 PBRs). We used PBRslenderness to analyze 261 PBRs in a low-seismicity setting to investigate the local geomorphic controls on PBR stability and preservation. PBRslenderness showed that a PBR's shape strongly controls its static stability and that there is no relationship between a PBR's stability and its geomorphic location in a drainage basin. However, the geomorphic settings of PBRs control their preservation potential by restricting their formation to hillslope gradients <40 degrees and the upper reaches of drainage basins. Such examples of our program's utility have led to its use in archival efforts of PBRs in southern California and Nevada, USA. Y1 - 2012 U6 - https://doi.org/10.1130/GES00788.1 SN - 1553-040X VL - 8 IS - 5 SP - 1042 EP - 1053 PB - American Institute of Physics CY - Boulder ER - TY - JOUR A1 - Thiede, Rasmus Christoph A1 - Arrowsmith, J. Ramón A1 - Bookhagen, Bodo A1 - McWilliams, Michael O. A1 - Sobel, Edward A1 - Strecker, Manfred T1 - Dome formation and extension in the Tethyan Himalaya, Leo Pargil, northwest India N2 - Metamorphic dome complexes occur within the internal structures of the northern Himalaya and southern Tibet. Their origin, deformation, and fault displacement patterns are poorly constrained. We report new field mapping, structural data, and cooling ages from the western flank of the Leo Pargil dome in the northwestern Himalaya in an attempt to characterize its post-middle Miocene structural development. The western flank of the dome is characterized by shallow, west-dipping pervasive foliation and WNW-ESE mineral lineation. Shear-sense indicators demonstrate that it is affected by east-west normal faulting that facilitated exhumation of high-grade metamorphic rocks in a contractional setting. Sustained top-to-northwest normal faulting during exhumation is observed in a progressive transition from ductile to brittle deformation. Garnet and kyanite indicate that the Leo Pargil dome was exhumed from the mid-crust. Ar- 40/Ar-39 mica and apatite fission track (AFT) ages constrain cooling and exhumation pathways front 350 to 60 degrees C and suggest that the dome cooled in three stages since the middle Miocene. Ar-40/Ar-39 white mica ages of 16-14 Ma suggest a first phase of rapid cooling and provide minimum estimates for the onset of dome exhumation. AFT ages between 10 and 8 Ma suggest that ductile fault displacement had ceased by then, and AFT track-length data from high-elevation samples indicate that the rate of cooling had decreased significantly. We interpret this to indicate decreased fault displacement along the Leo Pargil shear zone and possibly a transition to the Kaurik-Chango normal fault system between 10 and 6 Ma. AFT ages from lower elevations indicate accelerated cooling since the Pliocene that cannot be related to pure fault displacement, and therefore may reflect more pronounced regionally distributed and erosion-driven exhumation Y1 - 2006 U6 - https://doi.org/10.1130/B25872.1 ER - TY - JOUR A1 - Landgraf, Angela A1 - Zielke, Olaf A1 - Arrowsmith, J. Ramón A1 - Ballato, Paolo A1 - Strecker, Manfred A1 - Schildgen, Taylor F. A1 - Friedrich, Anke M. A1 - Tabatabaei, Sayyed-Hassan T1 - Differentiating simple and composite tectonic landscapes using numerical fault slip modeling with an example from the south central Alborz Mountains, Iran JF - Journal of geophysical research : Earth surface N2 - The tectonically driven growth of mountains reflects the characteristics of the underlying fault systems and the applied tectonic forces. Over time, fault networks might be relatively static, but stress conditions could change and result in variations in fault slip orientation. Such a tectonic landscape would transition from a simple to a composite state: the topography of simple landscapes is correlated with a single set of tectonic boundary conditions, while composite landscapes contain inherited topography due to earlier deformation under different boundary conditions. We use fault interaction modeling to compare vertical displacement fields with topographic metrics to differentiate the two types of landscapes. By successively rotating the axis of maximum horizontal stress, we produce a suite of vertical displacement fields for comparison with real landscapes. We apply this model to a transpressional duplex in the south central Alborz Mountains of Iran, where NW oriented compression was superseded by neotectonic NE compression. The consistency between the modeled displacement field and real landforms indicates that the duplex topography is mostly compatible with the modern boundary conditions, but might include a small remnant from the earlier deformation phase. Our approach is applicable for various tectonic settings and represents an approach to identify the changing boundary conditions that produce composite landscapes. It may be particularly useful for identifying changes that occurred in regions where river profiles may no longer record a signal of the change or where the spatial pattern of uplift is complex. KW - fault interaction KW - landscape evolution KW - numerical modeling KW - Alborz Mountains KW - Iran Y1 - 2013 U6 - https://doi.org/10.1002/jgrf.20109 SN - 2169-9003 SN - 2169-9011 VL - 118 IS - 3 SP - 1792 EP - 1805 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Thiede, Rasmus Christoph A1 - Bookhagen, Bodo A1 - Arrowsmith, J. Ramón A1 - Sobel, Edward A1 - Strecker, Manfred T1 - Climatic control on rapid exhumation along the Southern Himalayan Front N2 - Along the Southern Himalayan Front (SHF), areas with concentrated precipitation coincide with rapid exhumation, as indicated by young mineral cooling ages. Twenty new, young ( < 1-5 Ma) apatite fission track (AFT) ages have been obtained from the Himalayan Crystalline Core along the Sutlej Valley, NW India. The AFT ages correlate with elevation, but show no spatial relationship to tectonic structures, such as the Main Central Thrust or the Southern Tibetan Fault System. Monsoonal precipitation in this region exerts a strong influence on erosional surface processes. Fluvial erosional unloading along the SHF is focused on high mountainous areas, where the orographic barrier forces out > 80% of the annual precipitation. AFT cooling ages reveal a coincidence between rapid erosion and exhumation that is focused in a similar to 50-70-km-wide sector of the Himalaya, rather than encompassing the entire orogen. Assuming simplified constant exhumation rates, the rocks of two age vs. elevation transects were exhumed at similar to 1.4 +/- 0.2 and similar to 1.1 +/- 0.4 mm/a with an average cooling rate of similar to 40-50degreesC/Ma during Pliocene-Quarternary time. Following other recently published hypotheses regarding the relation between tectonics and climate in the Himalaya, we suggest that this concentrated loss of material was accommodated by motion along a back-stepping thrust to the south and a normal fault zone to the north as part of an extruding wedge. Climatically controlled erosional processes focus on this wedge and suggest that climatically controlled surface processes determine tectonic deformation in the internal part of the Himalaya. (C) 2004 Elsevier B.V. All rights reserved Y1 - 2004 SN - 0012-821X ER -