TY  - JOUR
A1  - Bande, Alejandro
A1  - Horton, Brian K.
A1  - Ramirez, Juan C.
A1  - Mora, Andres
A1  - Parra, Mauricio
A1  - Stockli, Daniel F.
T1  - Clastic deposition, provenance, and sequence of Andean thrusting in the frontal Eastern Cordillera and Llanos foreland basin of Colombia
JF  - Geological Society of America bulletin
N2  - Sedimentological, provenance, and detrital thermochronological results for basin fill at the modern deformation front of the northern Andes (6 degrees N latitude) provide a long-term, Eocene to Pliocene record of foreland-basin sedimentation along the Eastern Cordillera !Janos basin boundary in Colombia. Lithofacies assemblages and paleocurrent orientations in the upward-coarsening, 5-km-thick succession of the Nunchia syncline reveal a systematic shift from craton-derived, shallow-marine distal foreland (back-bulge) accumulation in the Mirador Formation, to orogen-sourced, deltaic, and coastalinfluenced sedimentation of the distal to medial foreland (foredeep) in the Carbonera and Leon Formations, to anastomosing fluvial and distributive braided fluvial megafan systems of the proximal foreland (foredeep to wedge-top) basin in the lower and upper Guayabo Formation. These changes in depositional processes and sediment dispersal are supported by up-section variations in detrital zircon U-Pb and (U-Th)/He ages that record exhumation of evolving, compartmentalized sediment source areas in the Eastern Cordillera. The data are interpreted in terms of a progressive eastward advance in foldand-thrust deformation, with late Eocene Oligocene deformation in the axial zone of the Eastern Cordillera along the western edge of Floresta basin (Soapaga thrust), early Miocene reactivation (inversion) of the eastern margin of the Mesozoic rift system (Pajarito and Guaicaramo thrusts), and middle late Miocene propagation of a footwall shortcut fault (Vopal thrust) that created the Nunchia syncline in a wedge-top (piggyback) setting of the eastern foothills along the transition from the Eastern Cordillera to Harms foreland basin. Collectively, the data presented here for the frontal Eastern Cordillera define a general in-sequence pattern of eastwardadvancing fold-and-thrust deformation during Cenozoic east-west shortening in the Colombian Andes.
Y1  - 2012
U6  - https://doi.org/10.1130/B30412.1
SN  - 0016-7606
VL  - 124
IS  - 1-2
SP  - 59
EP  - 76
PB  - American Institute of Physics
CY  - Boulder
ER  - 
TY  - JOUR
A1  - Wilke, Franziska Daniela Helena
A1  - Sobel, Edward
A1  - O'Brien, Patrick J.
A1  - Stockli, Daniel F.
T1  - Apatite fission track and (U-Th)/He ages from the Higher Himalayan Crystallines, Kaghan Valley, Pakistan: Implications for an Eocene Plateau and Oligocene to Pliocene exhumation
JF  - Journal of Asian earth sciences
N2  - Apatite fission track and apatite and zircon (U-Th)/He ages were obtained from high- and ultra high-pressure rocks from the Kaghan Valley, Pakistan. Four samples from the high altitude northern parts of the valley yielded apatite fission track ages between 24.5 +/- 3.7 and 15.6 +/- 2.1 Ma and apatite (U-Th)/He ages between 21.0 +/- 0.6 and 5.3 +/- 0.2 Ma. These data record cooling of the formerly deeply-subducted high-grade metamorphic rocks induced by denudation and exhumation consistent with extension and back sliding along the reactivated, normal-acting Main Mantle Thrust. Overlap at around 10 Ma between fission track and (U-Th)/He ages is recognised at one location (Besal) showing that fast cooling occurred due to brittle reactivation of a former thrust fault. Widespread Miocene cooling is also evident in adjacent areas to the west (Deosai Plateau, Tso Moran), most likely related to uplift and unroofing linked to continued underplating of the Indian lower crust beneath Ladakh and Kohistan in the Late Eocene to Oligocene. In the southernmost part of the study area, near Naran, two significantly younger Late Miocene to Pliocene apatite fission track ages of 7.6 +/- 2.1 to 4.0 +/- 0.5 Ma suggest a spatial and temporal separation of exhumation processes. These younger ages are best explained by enhanced Late Miocene uplift and erosion driven by thrusting along the Main Boundary Thrust.
KW  - NW Himalaya
KW  - Kaghan Valley
KW  - Thermochronology
KW  - AFT
KW  - (U-Th)/He
KW  - Cooling rates
Y1  - 2012
U6  - https://doi.org/10.1016/j.jseaes.2012.06.014
SN  - 1367-9120
VL  - 59
IS  - 3
SP  - 14
EP  - 23
PB  - Elsevier
CY  - Oxford
ER  -