|
|
|
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
1 Department of Geology, University of Leicester, and Natural Environment Research Council Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottinghamshire NG12 5GG, UK
2 Department of Earth Sciences, University of Oxford, Parks Road, Oxford OX1 3PR, UK
U-Pb ages of zircon and allanite from the coesite-bearing ultrahigh-pressure (UHP) units in the Kaghan Valley, northern Pakistan, demonstrate that peak UHP metamorphism along the northern margin of the Indian plate occurred at 46.4 ± 0.1 Ma at peak pressure-temperature conditions of >27.5 kbar (>100 km) and 720770 °C. Much lower pressure retrogressive growth of titanite took place between 46.4 and ca. 44 Ma, indicating that the eclogites were exhumed to 35 km depth at or before 44 Ma, implying very rapid exhumation rates within the mantle of
3080 mm/yr or more, comparable to rapid plate velocities. Once entrained in the base of the crust, the eclogites followed a slower cooling history from 45 Ma, similar to the amphibolite facies gneisses of the Pakistan Himalaya.
Key Words: ultrahigh-pressure metamorphism exhumation Pakistan Himalaya allanite UTh-Pb dating zircon coesite continental collision
This article has been cited by other articles:
![]() |
J. A. DiPietro, I. Ahmad, and A. Hussain Cenozoic kinematic history of the Kohistan fault in the Pakistan Himalaya Geological Society of America Bulletin, November 1, 2008; 120(11-12): 1428 - 1440. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Johnston, B. R. Hacker, and M. N. Ducea Exhumation of ultrahigh-pressure rocks beneath the Hornelen segment of the Nordfjord-Sogn Detachment Zone, western Norway Geological Society of America Bulletin, September 1, 2007; 119(9-10): 1232 - 1248. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. P. Searle Diagnostic features and processes in the construction and evolution of Oman-, Zagros-, Himalayan-, Karakoram-, and Tibetan-type orogenic belts Geological Society of America Memoirs, January 1, 2007; 200(0): 41 - 61. [Abstract] [Full Text] [PDF] |
||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |