|
|
|
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
,11 Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA
Five isotope-enhanced geologic transects in the southern Annapurna Range of central Nepal elucidate structural geometries near the Main Central thrust. Whole-rock Nd isotopes and U-Pb ages of detrital zircons unambiguously distinguish Greater Himalayan (hanging wall) and Lesser Himalayan (footwall) metasedimentary rocks.
Nd(0) values for lower Lesser Himalayan rocks typically range from 20 to 26, whereas Greater Himalayan rocks usually have
Nd(0) values of 19 to 12. Lower Lesser Himalayan rocks yield detrital zircons with an age peak at ca. 1880 Ma and no detrital zircons younger than ca. 1550 Ma. In contrast, Greater Himalayan rocks yield detrital zircons with a prominent broad peak of ages at ca. 1050 Ma and no detrital zircons younger than ca. 600 Ma. The protolith boundary between Greater and Lesser Himalayan rocks is up to 1 km farther south than usually mapped on the basis of lithology. Field and microstructural observations indicate the presence of a top-to-the-south ductile shear zone superimposed on this boundary, confirming this shear zone as the Main Central thrust. No evidence exists for large-scale structural mixing of Greater and Lesser Himalayan rocks along the Main Central thrust in the Annapurna Range.
Key Words: Himalaya Nepal tectonics Nd-143/Nd-144 U/Pb microstructure
This article has been cited by other articles:
![]() |
J. Celerier, T. M. Harrison, A. A. G. Webb, and A. Yin The Kumaun and Garwhal Lesser Himalaya, India: Part 1. Structure and stratigraphy Geological Society of America Bulletin, September 1, 2009; 121(9-10): 1262 - 1280. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. J. Martin Sub-millimeter Heterogeneity of Yttrium and Chromium during Growth of Semi-pelitic Garnet J. Petrology, September 1, 2009; 50(9): 1713 - 1727. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Groppo, F. Rolfo, and B. Lombardo P-T Evolution across the Main Central Thrust Zone (Eastern Nepal): Hidden Discontinuities Revealed by Petrology J. Petrology, June 1, 2009; 50(6): 1149 - 1180. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. A. Kellett and L. Godin Pre-Miocene deformation of the Himalayan superstructure, Hidden valley, central Nepal Journal of the Geological Society, March 1, 2009; 166(2): 261 - 275. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. P. Larson and L. Godin Kinematics of the Greater Himalayan sequence, Dhaulagiri Himal: implications for the structural framework of central Nepal Journal of the Geological Society, January 1, 2009; 166(1): 25 - 43. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. M. Robinson Forward modeling the kinematic sequence of the central Himalayan thrust belt, western Nepal Geosphere, October 1, 2008; 4(5): 785 - 801. [Abstract] [Full Text] [PDF] |
||||
![]() |
J.A. CHAMBERS, T.W. ARGLES, M.S.A. HORSTWOOD, N.B.W. HARRIS, R.R. PARRISH, and T. AHMAD Tectonic implications of Palaeoproterozoic anatexis and Late Miocene metamorphism in the Lesser Himalayan Sequence, Sutlej Valley, NW India Journal of the Geological Society, May 1, 2008; 165(3): 725 - 737. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. P. SEARLE, R. D. LAW, L. GODIN, K. P. LARSON, M. J. STREULE, J. M. COTTLE, and M. J. JESSUP Defining the Himalayan Main Central Thrust in Nepal Journal of the Geological Society, March 1, 2008; 165(2): 523 - 534. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. J. Kohn P-T-t data from central Nepal support critical taper and repudiate large-scale channel flow of the Greater Himalayan Sequence Geological Society of America Bulletin, March 1, 2008; 120(3-4): 259 - 273. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. A. Murphy Isotopic characteristics of the Gurla Mandhata metamorphic core complex: Implications for the architecture of the Himalayan orogen Geology, November 1, 2007; 35(11): 983 - 986. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. J. Catlos, C. Shekhar Dubey, R. A. Marston, and T. M. Harrison Geochronologic constraints across the Main Central Thrust shear zone, Bhagirathi River (NW India): Implications for Himalayan tectonics Geological Society of America Special Papers, January 1, 2007; 419(0): 135 - 151. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. M. Robinson, P. G. DeCelles, and P. Copeland Tectonic evolution of the Himalayan thrust belt in western Nepal: Implications for channel flow models Geological Society of America Bulletin, July 1, 2006; 118(7-8): 865 - 885. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Richards, R. Parrish, N. Harris, T. Argles, and L. Zhang Correlation of lithotectonic units across the eastern Himalaya, Bhutan Geology, May 1, 2006; 34(5): 341 - 344. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. Godin, D. Grujic, R. D. Law, and M. P. Searle Channel flow, ductile extrusion and exhumation in continental collision zones: an introduction Geological Society, London, Special Publications, January 1, 2006; 268(1): 1 - 23. [Abstract] [PDF] |
||||
![]() |
R. A. Jamieson, C. Beaumont, M. H. Nguyen, and D. Grujic Provenance of the Greater Himalayan Sequence and associated rocks: predictions of channel flow models Geological Society, London, Special Publications, January 1, 2006; 268(1): 165 - 182. [Abstract] [PDF] |
||||
![]() |
D. M. Robinson and O. N. Pearson Exhumation of Greater Himalayan rock along the Main Central Thrust in Nepal: implications for channel flow Geological Society, London, Special Publications, January 1, 2006; 268(1): 255 - 267. [Abstract] [PDF] |
||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |