TY  - JOUR
A1  - Haghipour, Negar
A1  - Burg, Jean-Pierre
A1  - Kober, Florian
A1  - Zeilinger, Gerold
A1  - Ivy-Ochs, Susan
A1  - Kubik, Peter W.
A1  - Faridi, Mohammad
T1  - Rate of crustal shortening and non-Coulomb behaviour of an active accretionary wedge - the folded fluvial terraces in Makran (SE, Iran)
JF  - Earth & planetary science letters
N2  - We surveyed fluvial terraces to decipher the Quaternary increment of crustal shortening and shortening rate in the on-shore Makran Accretionary Wedge. We focused on three major catchment basins and associated fold systems. Terrace profiles reconstructed from differential GPS measurements combined with DEM revealed two regional dominant wavelengths, about 5 km in the northern part of the study area and about 15 km to the south. These two wavelengths suggest the existence of two active decollement layers at two rooting depths. The average shortening rate due to folding is estimated at 0.8-1.2 mm/a over the last 130 ka. This accounts for 10-15% of the shortening rate (similar to 8 mm/a) given by kinematic GPS measurements between Chabahar and Bazman and 3% of the convergence between Arabia and Eurasia, across the Makran subduction zone. Despite active deformation and a relatively high shortening rate, the geophysical record shows nearly absent seismic activity in Makran. We propose that strain accumulated in folds over intermediate decollement levels within a thick, incompletely lithified sedimentary cover explains the essentially aseismic, recent tectonics in this region. The importance of folds points to imperfect Coulomb behaviour of the wedge. (C) 2012 Elsevier B.V. All rights reserved.
KW  - fluvial terraces
KW  - Be-10 dating
KW  - accretionary wedge
KW  - shortening rate
Y1  - 2012
U6  - https://doi.org/10.1016/j.epsl.2012.09.001
SN  - 0012-821X
VL  - 355
SP  - 187
EP  - 198
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Hemingway, Jordon Dennis
A1  - Hilton, Robert G.
A1  - Hovius, Niels
A1  - Eglinton, Timothy I.
A1  - Haghipour, Negar
A1  - Wacker, Lukas
A1  - Chen, Meng-Chiang
A1  - Galy, Valier V.
T1  - Microbial oxidation of lithospheric organic carbon in rapidly eroding tropical mountain soils
JF  - Science
N2  - Lithospheric organic carbon ("petrogenic"; OCpetro) is oxidized during exhumation and subsequent erosion of mountain ranges. This process is a considerable source of carbon dioxide (CO2) to the atmosphere over geologic time scales, but the mechanisms that govern oxidation rates in mountain landscapes are poorly constrained. We demonstrate that, on average, 67 +/- 11% of the OCpetro initially present in bedrock exhumed from the tropical, rapidly eroding Central Range of Taiwan is oxidized in soils, leading to CO2 emissions of 6.1 to 18.6 metric tons of carbon per square kilometer per year. The molecular and isotopic evolution of bulk OC and lipid biomarkers during soil formation reveals that OCpetro remineralization is microbially mediated. Rapid oxidation in mountain soils drives CO2 emission fluxes that increase with erosion rate, thereby counteracting CO2 drawdown by silicate weathering and biospheric OC burial.
Y1  - 2018
U6  - https://doi.org/10.1126/science.aao6463
SN  - 0036-8075
SN  - 1095-9203
VL  - 360
IS  - 6385
SP  - 209
EP  - +
PB  - American Assoc. for the Advancement of Science
CY  - Washington
ER  - 
TY  - JOUR
A1  - Menges, Johanna
A1  - Hovius, Niels
A1  - Andermann, Christoff
A1  - Lupker, Maarten
A1  - Haghipour, Negar
A1  - Märki, Lena
A1  - Sachse, Dirk
T1  - Variations in organic carbon sourcing along a trans-Himalayan river determined by a Bayesian mixing approach
JF  - Geochimica et cosmochimica acta : journal of the Geochemical Society and the Meteoritical Society
N2  - Rivers transfer particulate organic carbon (POC) from eroding mountains into geological sinks. Organic carbon source composition and selective mobilization have been shown to affect the type and quantity of POC export, but their combined effects across complex mountain ranges remain underexplored. Here, we examine the variation in organic carbon sourcing and transport in the trans-Himalayan Kali Gandaki River catchment, along strong gradients in precipitation, rock type and vegetation. Combining bulk stable nitrogen, and stable and radioactive organic carbon isotopic composition of bedrock, litter, soil and river sediment samples with a Bayesian end-member mixing approach, we differentiate POC sources along the river and quantify their export. Our analysis shows that POC export from the Tibetan segment of the catchment, where carbon bearing shales are partially covered by aged and modern soils, is dominated by petrogenic POC. Based on our data we re-assess the presence of aged biospheric OC in this part of the catchment, and its contribution to the river load. In the High Himalayan segment, we observed low inputs of petrogenic and biospheric POC, likely due to very low organic carbon concentrations in the metamorphic bedrock, combined with erosion dominated by deep-seated landslides. Our findings show that along the Kali Gandaki River, the sourcing of sediment and organic carbon are decoupled, due to differences in rock organic carbon content, soil and above ground carbon stocks, and geomorphic process activity. While the fast eroding High Himalayas are the principal source of river sediment, the Tibetan headwaters, where erosion rates are lower, are the principal source of organic carbon. To robustly estimate organic carbon export from the Himalayas, the mountain range should be divided into tectono-physiographic zones with distinct organic carbon yields due to differences in substrate and erosion processes and rates.
KW  - particulate organic carbon
KW  - Himalaya
KW  - rivers
KW  - carbon cycle
KW  - stable
KW  - isotopes
KW  - erosion
KW  - end-member mixing
Y1  - 2020
U6  - https://doi.org/10.1016/j.gca.2020.07.003
SN  - 0016-7037
VL  - 286
SP  - 159
EP  - 176
PB  - Elsevier
CY  - New York [u.a.]
ER  -