| Title | Eocene deep crust at Ama Drime, Tibet: early evolution of the Himalayan orogen |
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| Author | Kellett, D A ;
Cottle, J M; Smit, M |
| Source | Lithosphere vol. 6, no. 4, 2014 p. 220-229, https://doi.org/10.1130/L350.1  Open Access |
| Image |  |
| Year | 2014 |
| Alt Series | Earth Sciences Sector, Contribution Series 20120286 |
| Publisher | Geological Society of America |
| Document | serial |
| Lang. | English |
| Media | paper; digital; on-line |
| File format | pdf; html |
| Area | Ama Drime; Kharta; India |
| Lat/Long WENS | 87.1667 87.8333 28.5000 28.0000 |
| Subjects | tectonics; geochronology; Eocene; orogenesis; orogenic regions; tectonic interpretations; tectonic evolution; tectonic setting; metamorphism; zircon; zircon dates; radiometric dating; uranium lead
dating; Cenozoic |
| Illustrations | location maps; cross-sections; photomicrographs; plots; tables |
| Program | GEM: Geo-mapping for Energy and Minerals GSC Science Laboratory Network |
| Released | 2014 08 01 |
| Abstract | Timing of garnet growth in deep-crustal rocks exposed in the Ama Drime massif of southern Tibet was constrained by Lu-Hf dating. Garnet from three mafic granulitized eclogites, hosted by the Ama Drime
felsic orthogneiss, yielded 36.1 ± 1.9 Ma, 37.5 ± 0.9 Ma and 34.1 ± 0.8 Ma. These ages are the oldest reported from the central-eastern Himalaya for deep burial of the Indian lower crust beneath Tibet, and demonstrate that this process started as
early as the Eocene following the collision of India and Asia. Unlike the ultra-high pressure eclogites of the northwest Himalaya, the Ama Drime eclogites were not rapidly exhumed as a cold slab, but spent >20 million years in the lower and middle
crust before being exhumed to shallow crustal levels in the mid- to late-Miocene. |
| GEOSCAN ID | 291989 |
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