TY  - JOUR
A1  - Stübner, Konstanze
A1  - Grujic, Djordje
A1  - Dunkl, Istvan
A1  - Thiede, Rasmus  Christoph
A1  - Eugster, Patricia
T1  - Pliocene episodic exhumation and the significance of the Munsiari thrust in the northwestern Himalaya
JF  - Earth & planetary science letters
N2  - The Himalayan thrust belt comprises three in-sequence foreland-propagating orogen-scale faults, the Main Central thrust, the Main Boundary thrust, and the Main Frontal thrust. Recently, the Munsiari–Ramgarh–Shumar thrust system has been recognized as an additional, potentially orogen-scale shear zone in the proximal footwall of the Main Central thrust. The timing of the Munsiari, Ramgarh, and Shumar thrusts and their role in Himalayan tectonics are disputed. We present 31 new zircon (U–Th)/He ages from a profile across the central Himachal Himalaya in the Beas River area. Within a ∼40 km wide belt northeast of the Kullu–Larji–Rampur window, ages ranging from to constrain a distinct episode of rapid Pliocene to Present exhumation; north and south of this belt, zircon (U–Th)/He ages are older ( to ). We attribute the Pliocene rapid exhumation episode to basal accretion to the Himalayan thrust belt and duplex formation in the Lesser Himalayan sequence including initiation of the Munsiari thrust. Pecube thermokinematic modelling suggests exhumation rates of ∼2–3 mm/yr from 4–7 to 0 Ma above the duplex contrasting with lower (<0.3 mm/yr) middle-late Miocene exhumation rates. The Munsiari thrust terminates laterally in central Himachal Pradesh. In the NW Indian Himalaya, the Main Central thrust zone comprises the sheared basal sections of the Greater Himalayan sequence and the mylonitic ‘Bajaura nappe’ of Lesser Himalayan affinity. We correlate the Bajaura unit with the Ramgarh thrust sheet in Nepal based on similar lithologies and the middle Miocene age of deformation. The Munsiari thrust in the central Himachal Himalaya is several Myr younger than deformation in the Bajaura and Ramgarh thrust sheets. Our results illustrate the complex and segmented nature of the Munsiari–Ramgarh–Shumar thrust system.
KW  - Himalaya
KW  - Himachal Pradesh
KW  - Munsiari thrust
KW  - thermochronology
KW  - thermokinematic modelling
KW  - Pliocene
Y1  - 2017
U6  - https://doi.org/10.1016/j.epsl.2017.10.036
SN  - 0012-821X
SN  - 1385-013X
VL  - 481
SP  - 273
EP  - 283
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Loebens, Stefan
A1  - Sobel, Edward
A1  - Bense, Frithjof A.
A1  - Wemmer, Klaus
A1  - Dunkl, Istvan
A1  - Siegesmund, Siegfried
T1  - Refined exhumation history of the northern Sierras Pampeanas, Argentina
JF  - Tectonics
N2  - The Sierra de Aconquija and Cumbres Calchaquies in the thick-skinned northern Sierras Pampeanas, NW Argentina present an ideal setting to investigate the tectonically and erosionally controlled exhumation and uplift history of mountain ranges using thermochronological methods. Although these ranges are located along strike of one another, their spatiotemporal evolution varies significantly. Integrating modeled cooling histories constrained by K-Ar ages of muscovite and biotite, apatite fission track data as well as (U-Th)/He measurement of zircon and apatite reveal the structural evolution of these ranges beginning in the late stage of the Paleozoic Famatinian Orogeny. Following localized rift-related exhumation in the central part of the study area and slow erosion elsewhere, growth of the modern topography commenced in the Cenozoic during Andean deformation. The main activity occurred during the late Miocene, with varying magnitudes of rock uplift, surface uplift, and exhumation in the two mountain ranges. The Cumbres Calchaquies is characterized by a total of 5-7km of vertical rock uplift, around 3km of crestal surface uplift, and a maximum exhumation of 2-4km since that time. The Sierra de Aconquija experienced 10-13km of vertical rock uplift, similar to 4-5km of peak surface uplift, and 6-8km of exhumation since around 9Ma. Much of this exhumation occurred along a previously poorly recognized fault. Miocene reactivation of Cretaceous rift structures may explain along-strike variations within these ranges. Dating of sedimentary samples from adjacent basins supports the evolutionary model developed for the mountain ranges.
KW  - Thermochronology
KW  - Sierras Pampeanas
KW  - thermal modeling
KW  - exhumation and uplift
Y1  - 2013
U6  - https://doi.org/10.1002/tect.20038
SN  - 0278-7407
VL  - 32
IS  - 3
SP  - 453
EP  - 472
PB  - American Geophysical Union
CY  - Washington
ER  -