TY  - JOUR
A1  - Yildirim, Cengiz
A1  - Schildgen, Taylor F.
A1  - Echtler, Helmut Peter
A1  - Melnick, Daniel
A1  - Bookhagen, Bodo
A1  - Ciner, T. Attila
A1  - Niedermann, Samuel
A1  - Merchel, Silke
A1  - Martschini, Martin
A1  - Steier, Peter
A1  - Strecker, Manfred
T1  - Tectonic implications of fluvial incision and pediment deformation at the northern margin of the Central Anatolian Plateau based on multiple cosmogenic nuclides
JF  - Tectonics
N2  - We document Quaternary fluvial incision driven by fault-controlled surface deformation in the inverted intermontane Gökirmak Basin in the Central Pontide mountains along the northern margin of the Central Anatolian Plateau. In-situ-produced Be-10, Ne-21, and Cl-36 concentrations from gravel-covered fluvial terraces and pediment surfaces along the trunk stream of the basin (the Gökirmak River) yield model exposure ages ranging from 71ka to 34645ka and average fluvial incision rates over the past similar to 350ka of 0.280.01mm a(-1). Similarities between river incision rates and coastal uplift rates at the Black Sea coast suggest that regional uplift is responsible for the river incision. Model exposure ages of deformed pediment surfaces along tributaries of the trunk stream range from 605ka to 110 +/- 10ka, demonstrating that the thrust faults responsible for pediment deformation were active after those times and were likely active earlier as well as explaining the topographic relief of the region. Together, our data demonstrate cumulative incision that is linked to active internal shortening and uplift of similar to 0.3mm a(-1) in the Central Pontide orogenic wedge, which may ultimately contribute to the lateral growth of the northern Anatolian Plateau.
KW  - Tectonic Geomorphology
KW  - Fluvial Incision
KW  - Surface Exposure Age
KW  - Uplift Rate
Y1  - 2013
U6  - https://doi.org/10.1002/tect.20066
SN  - 0278-7407
SN  - 1944-9194
VL  - 32
IS  - 5
SP  - 1107
EP  - 1120
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Schildgen, Taylor F.
A1  - Cosentino, D.
A1  - Bookhagen, Bodo
A1  - Niedermann, Samuel
A1  - Yildirim, C.
A1  - Echtler, Helmut Peter
A1  - Wittmann, Hella
A1  - Strecker, Manfred
T1  - Multi-phased uplift of the southern margin of the Central Anatolian plateau, Turkey a record of tectonic and upper mantle processes
JF  - Earth & planetary science letters
N2  - Uplifted Neogene marine sediments and Quaternary fluvial terraces in the Mut Basin, southern Turkey, reveal a detailed history of surface uplift along the southern margin of the Central Anatolian plateau from the Late Miocene to the present. New surface exposure ages (Be-10, Al-26, and Ne-21) of gravels capping fluvial strath terraces located between 28 and 135 m above the Goksu River in the Mut Basin yield ages ranging from ca. 25 to 130 ka, corresponding to an average incision rate of 0.52 to 0.67 mm/yr. Published biostratigraphic data combined with new interpretations of the fossil assemblages from uplifted marine sediments reveal average uplift rates of 0.25 to 0.37 mm/yr since Late Miocene time (starting between 8 and 5.45 Ma), and 0.72 to 0.74 mm/yr after 1.66 to 1.62 Ma. Together with the terrace abandonment ages, the data imply 0.6 to 0.7 mm/yr uplift rates from 1.6 Ma to the present. The different post-Late Miocene and post-1.6 Ma uplift rates can imply increasing uplift rates through time, or multi-phased uplift with slow uplift or subsidence in between. Longitudinal profiles of rivers in the upper catchment of the Mut and Ermenek basins show no apparent lithologic or fault control on some knickpoints that occur at 1.2 to 1.5 km elevation, implying a transient response to a change in uplift rates. Projections of graded upper relict channel segments to the modern outlet, together with constraints from uplifted marine sediments, show that a slower incision/uplift rate of 0.1 to 0.2 mm/yr preceded the 0.7 mm/yr uplift rate. The river morphology and profile projections therefore reflect multi-phased uplift of the plateau margin, rather than steadily increasing uplift rates. Multi-phased uplift can be explained by lithospheric slab break-off and possibly also the arrival of the Eratosthenes Seamount at the collision zone south of Cyprus.
KW  - Central Anatolian plateau
KW  - uplift
KW  - fluvial strath terraces
KW  - cosmogenic nuclides
KW  - biostratigraphy
KW  - channel projection
Y1  - 2012
U6  - https://doi.org/10.1016/j.epsl.2011.12.003
SN  - 0012-821X
VL  - 317
SP  - 85
EP  - 95
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Montero-Lopez, Carolina
A1  - Strecker, Manfred
A1  - Schildgen, Taylor F.
A1  - Hongn, Fernando D.
A1  - Guzman, Silvina
A1  - Bookhagen, Bodo
A1  - Sudo, Masafumi
T1  - Local high relief at the southern margin of the Andean plateau by 9 Ma: evidence from ignimbritic valley fills and river incision
JF  - Terra nova
N2  - A valley-filling ignimbrite re-exposed through subsequent river incision at the southern margin of the Andean (Puna) plateau preserves pristine geological evidence of pre-late Miocene palaeotopography in the north western Argentine Andes. Our new Ar-40/(39) Ar dating of the Las Papas Ignimbrites yields a plateau age of 9.24 +/- 0.03 Ma, indicating valley-relief and orographic-barrier conditions comparable to the present-day. A later infill of Plio-Pleistocene coarse conglomerates has been linked to wetter conditions, but resulted in no additional net incision of the Las Papas valley, considering that the base of the ignimbrite remains unexposed in the valley bottom. Our observations indicate that at least 550 m of local plateau margin relief (and likely > 2 km) existed by 9 Ma at the southern Puna margin, which likely aided the efficiency of the orographic barrier to rainfall along the eastern and south eastern flanks of the Puna and causes aridity in the plateau interior.
Y1  - 2014
U6  - https://doi.org/10.1111/ter.12120
SN  - 0954-4879
SN  - 1365-3121
VL  - 26
IS  - 6
SP  - 454
EP  - 460
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Schildgen, Taylor F.
A1  - Robinson, Ruth A. J.
A1  - Savi, Sara
A1  - Phillips, William M.
A1  - Spencer, Joel Q. G.
A1  - Bookhagen, Bodo
A1  - Scherler, Dirk
A1  - Tofelde, Stefanie
A1  - Alonso, Ricardo N.
A1  - Kubik, Peter W.
A1  - Binnie, Steven A.
A1  - Strecker, Manfred
T1  - Landscape response to late Pleistocene climate change in NW Argentina: Sediment flux modulated by basin geometry and connectivity
JF  - Journal of geophysical research : Earth surface
N2  - Fluvial fill terraces preserve sedimentary archives of landscape responses to climate change, typically over millennial timescales. In the Humahuaca Basin of NW Argentina (Eastern Cordillera, southern Central Andes), our 29 new optically stimulated luminescence ages of late Pleistocene fill terrace sediments demonstrate that the timing of past river aggradation occurred over different intervals on the western and eastern sides of the valley, despite their similar bedrock lithology, mean slopes, and precipitation. In the west, aggradation coincided with periods of increasing precipitation, while in the east, aggradation coincided with decreasing precipitation or more variable conditions. Erosion rates and grain size dependencies in our cosmogenic Be-10 analyses of modern and fill terrace sediments reveal an increased importance of landsliding compared to today on the west side during aggradation, but of similar importance during aggradation on the east side. Differences in the timing of aggradation and the Be-10 data likely result from differences in valley geometry, which causes sediment to be temporarily stored in perched basins on the east side. It appears as if periods of increasing precipitation triggered landslides throughout the region, which induced aggradation in the west, but blockage of the narrow bedrock gorges downstream from the perched basins in the east. As such, basin geometry and fluvial connectivity appear to strongly influence the timing of sediment movement through the system. For larger basins that integrate subbasins with differing geometries or degrees of connectivity (like Humahuaca), sedimentary responses to climate forcing are likely attenuated.
KW  - berylium-10
KW  - optically stimulated luminescence
KW  - Humahuaca Basin
KW  - South American Monsoon System
KW  - fluvial terraces
KW  - landscape connectivity
Y1  - 2016
U6  - https://doi.org/10.1002/2015JF003607
SN  - 2169-9003
SN  - 2169-9011
VL  - 121
SP  - 392
EP  - 414
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Dey, Saptarshi
A1  - Thiede, Rasmus Christoph
A1  - Schildgen, Taylor F.
A1  - Wittmann, Hella
A1  - Bookhagen, Bodo
A1  - Scherler, Dirk
A1  - Strecker, Manfred
T1  - Holocene internal shortening within the northwest Sub-Himalaya: Out-of-sequence faulting of the Jwalamukhi Thrust, India
JF  - Tectonics
N2  - The southernmost thrust of the Himalayan orogenic wedge that separates the foreland from the orogen, the Main Frontal Thrust, is thought to accommodate most of the ongoing crustal shortening in the Sub-Himalaya. Steepened longitudinal river profile segments, terrace offsets, and back-tilted fluvial terraces within the Kangra reentrant of the NW Sub-Himalaya suggest Holocene activity of the Jwalamukhi Thrust (JMT) and other thrust faults that may be associated with strain partitioning along the toe of the Himalayan wedge. To assess the shortening accommodated by the JMT, we combine morphometric terrain analyses with in situ Be-10-based surface-exposure dating of the deformed terraces. Incision into upper Pleistocene sediments within the Kangra Basin created two late Pleistocene terrace levels (T1 and T2). Subsequent early Holocene aggradation shortly before similar to 10ka was followed by episodic reincision, which created four cut-and-fill terrace levels, the oldest of which (T3) was formed at 10.10.9ka. A vertical offset of 445m of terrace T3 across the JMT indicates a shortening rate of 5.60.8 to 7.51.1mma(-1) over the last similar to 10ka. This result suggests that thrusting along the JMT accommodates 40-60% of the total Sub-Himalayan shortening in the Kangra reentrant over the Holocene. We speculate that this out-of-sequence shortening may have been triggered or at least enhanced by late Pleistocene and Holocene erosion of sediments from the Kangra Basin.
KW  - fluvial terrace
KW  - cosmogenic nuclides
KW  - steepness index
KW  - Jwalamukhi Thrust
KW  - shortening
KW  - orogenic wedge
Y1  - 2016
U6  - https://doi.org/10.1002/2015TC004002
SN  - 0278-7407
SN  - 1944-9194
VL  - 35
SP  - 2677
EP  - 2697
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Acosta, Veronica Torres
A1  - Schildgen, Taylor F.
A1  - Clarke, Brian A.
A1  - Scherler, Dirk
A1  - Bookhagen, Bodo
A1  - Wittmann, Hella
A1  - von Blanckenburg, Friedhelm
A1  - Strecker, Manfred
T1  - Effect of vegetation cover on millennial-scale landscape denudation rates in East Africa
JF  - Lithosphere
N2  - The mechanisms by which climate and vegetation affect erosion rates over various time scales lie at the heart of understanding landscape response to climate change. Plot-scale field experiments show that increased vegetation cover slows erosion, implying that faster erosion should occur under low to moderate vegetation cover. However, demonstrating this concept over long time scales and across landscapes has proven to be difficult, especially in settings complicated by tectonic forcing and variable slopes. We investigate this problem by measuring cosmogenic Be-10-derived catchment-mean denudation rates across a range of climate zones and hillslope gradients in the Kenya Rift, and by comparing our results with those published from the Rwenzori Mountains of Uganda. We find that denudation rates from sparsely vegetated parts of the Kenya Rift are up to 0.13 mm/yr, while those from humid and more densely vegetated parts of the Kenya Rift flanks and the Rwenzori Mountains reach a maximum of 0.08 mm/yr, despite higher median hillslope gradients. While differences in lithology and recent land-use changes likely affect the denudation rates and vegetation cover values in some of our studied catchments, hillslope gradient and vegetation cover appear to explain most of the variation in denudation rates across the study area. Our results support the idea that changing vegetation cover can contribute to complex erosional responses to climate or land-use change and that vegetation cover can play an important role in determining the steady-state slopes of mountain belts through its stabilizing effects on the land surface.
Y1  - 2015
U6  - https://doi.org/10.1130/L402.1
SN  - 1941-8264
SN  - 1947-4253
VL  - 7
IS  - 4
SP  - 408
EP  - 420
PB  - American Institute of Physics
CY  - Boulder
ER  - 
TY  - JOUR
A1  - Dey, Saptarshi
A1  - Thiede, Rasmus Christoph
A1  - Schildgen, Taylor F.
A1  - Wittmann, Hella
A1  - Bookhagen, Bodo
A1  - Scherler, Dirk
A1  - Jain, Vikrant
A1  - Strecker, Manfred
T1  - Climate-driven sediment aggradation and incision since the late Pleistocene in the NW Himalaya, India
JF  - Earth & planetary science letters
N2  - Deciphering the response of sediment routing systems to climatic forcing is fundamental for understanding the impacts of climate change on landscape evolution. In the Kangra Basin (northwest Sub-Himalaya, India), upper Pleistocene to Holocene alluvial fills and fluvial terraces record periodic fluctuations of sediment supply and transport capacity on timescales of 10(3) to 10(5) yr. To evaluate the potential influence of climate change on these fluctuations, we compare the timing of aggradation and incision phases recorded within remnant alluvial fans and terraces with climate archives. New surface-exposure dating of six terrace levels with in-situ cosmogenic Be-10 indicates the onset of incision phases. Two terrace surfaces from the highest level (T1) sculpted into the oldest preserved alluvial fan (AF1) date back to 53.4 +/- 3.2 ka and 43.0 +/- 2.7 ka (1 sigma). T2 surfaces sculpted into the remnants of AF1 have exposure ages of 18.6 +/- 1.2 ka and 15.3 +/- 0.9 ka, while terraces sculpted into the upper Pleistocene-Holocene fan (AF2) provide ages of 9.3 +/- 0.4 ka (T3), 7.1 +/- 0.4 ka (T4), 5.2 +/- 0.4 ka (T5) and 3.6 +/- 0.2 ka (T6). Together with previously published OSL ages yielding the timing of aggradation, we find a correlation between variations in sediment transport with oxygen-isotope records from regions affected by the Indian Summer Monsoon. During periods of increased monsoon intensity and post-Last Glacial Maximum glacial retreat, aggradation occurred in the Kangra Basin, likely due to high sediment flux, whereas periods of weakened monsoon intensity or lower sediment supply coincide with incision. (C) 2016 Elsevier B.V. All rights reserved.
KW  - alluvial-fan sedimentation
KW  - terrestrial cosmogenic nuclides
KW  - Indian Summer Monsoon
KW  - Last Glacial Maximum
KW  - paleo-erosion rate
Y1  - 2016
U6  - https://doi.org/10.1016/j.epsl.2016.05.050
SN  - 0012-821X
SN  - 1385-013X
VL  - 449
SP  - 321
EP  - 331
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Rohrmann, Alexander
A1  - Strecker, Manfred
A1  - Bookhagen, Bodo
A1  - Mulch, Andreas
A1  - Sachse, Dirk
A1  - Pingel, Heiko
A1  - Alonso, Ricardo N.
A1  - Schildgen, Taylor F.
A1  - Montero, Carolina
T1  - Can stable isotopes ride out the storms? The role of convection for water isotopes in models, records, and paleoaltimetry studies in the central Andes
JF  - Earth & planetary science letters
KW  - stable isotopes
KW  - Andes
KW  - precipitation
KW  - convection
KW  - paleoaltimetry
KW  - TRMM satellite data
Y1  - 2014
U6  - https://doi.org/10.1016/j.epsl.2014.09.021
SN  - 0012-821X
SN  - 1385-013X
VL  - 407
SP  - 187
EP  - 195
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Tofelde, Stefanie
A1  - Schildgen, Taylor F.
A1  - Savi, Sara
A1  - Pingel, Heiko
A1  - Wickert, Andrew D.
A1  - Bookhagen, Bodo
A1  - Wittmann, Hella
A1  - Alonso, Ricardo N.
A1  - Cottle, John
A1  - Strecker, Manfred
T1  - 100 kyr fluvial cut-and-fill terrace cycles since the Middle Pleistocene in the southern Central Andes, NW Argentina
JF  - Earth & planetary science letters
N2  - Fluvial fill terraces in intermontane basins are valuable geomorphic archives that can record tectonically and/or climatically driven changes of the Earth-surface process system. However, often the preservation of fill terrace sequences is incomplete and/or they may form far away from their source areas, complicating the identification of causal links between forcing mechanisms and landscape response, especially over multi-millennial timescales. The intermontane Toro Basin in the southern Central Andes exhibits at least five generations of fluvial terraces that have been sculpted into several-hundred-meter-thick Quaternary valley-fill conglomerates. New surface-exposure dating using nine cosmogenic Be-10 depth profiles reveals the successive abandonment of these terraces with a 100 kyr cyclicity between 75 +/- 7 and 487 +/- 34 ka. Depositional ages of the conglomerates, determined by four Al-26/Be-10 burial samples and U-Pb zircon ages of three intercalated volcanic ash beds, range from 18 +/- 141 to 936 +/- 170 ka, indicating that there were multiple cut-and-fill episodes. Although the initial onset of aggradation at similar to 1 Ma and the overall net incision since ca. 500 ka can be linked to tectonic processes at the narrow basin outlet, the superimposed 100 kyr cycles of aggradation and incision are best explained by eccentricity-driven climate change. Within these cycles, the onset of river incision can be correlated with global cold periods and enhanced humid phases recorded in paleoclimate archives on the adjacent Bolivian Altiplano, whereas deposition occurred mainly during more arid phases on the Altiplano and global interglacial periods. We suggest that enhanced runoff during global cold phases - due to increased regional precipitation rates, reduced evapotranspiration, or both - resulted in an increased sediment-transport capacity in the Toro Basin, which outweighed any possible increases in upstream sediment supply and thus triggered incision. Compared with two nearby basins that record precessional (21-kyr) and long-eccentricity (400-kyr) forcing within sedimentary and geomorphic archives, the recorded cyclicity scales with the square of the drainage basin length. (C) 2017 Elsevier B.V. All rights reserved.
KW  - Be-10 depth-profiles
KW  - surface inflation
KW  - aggradation-incision cycles
KW  - glacial-interglacial cycles
KW  - landscape response to climate change
KW  - Eastern Cordillera
Y1  - 2017
U6  - https://doi.org/10.1016/j.epsl.2017.06.001
SN  - 0012-821X
SN  - 1385-013X
VL  - 473
SP  - 141
EP  - 153
PB  - Elsevier
CY  - Amsterdam
ER  -