Skip navigation
Please use this identifier to cite or link to this item:
Title: Polyphase development of chocolate-tablet boudins in the SAT zone, Kumaun Lesser Himalaya, India
Authors: Ojha A.K.
Sharma R.
Srivastava D.C.
Lister G.S.
Published in: Journal of Structural Geology
Abstract: A combination of two groups of boudins, exposed in orthogonal sections, is observed as chocolate tablet structures in the South Almora Thrust (SAT) zone, Kumaun Lesser Himalaya. Evidence from boudin associated veins, fractures, folds and microstructures suggest that the chocolate-tablet boudins were developed as a consequence of layer-parallel stretching in two orthogonal directions during two successive phases of ductile shearing in the SAT zone. The early phase of top-to-NW shearing is speculated as a pre-Himalayan deformation during which the early boudins were developed. This deformation was superposed by a late phase of top-to-SW Himalayan shearing and development of the attendant late boudins. It is concluded that the interference of two phases of successively developed boudins has resulted into development of the chocolate tablet structures in the SAT. Fluid inclusion and microstructures indicate a low temperature, about 300 °C, growth of the chocolate-tablet boudins. The finite strain analysis reveals that a maximum strain ratio (Rs) of 1.7 was accumulated during the pre-Himalayan phase of deformation whereas Rs was of the order of 2.1 in the Himalayan phase of deformation. © 2019
Citation: Journal of Structural Geology (2019), 127(): -
Issue Date: 2019
Publisher: Elsevier Ltd
ISSN: 1918141
Author Scopus IDs: 56088557800
Author Affiliations: Ojha, A.K., Indian Institute of Technology Roorkee, Roorkee, 247 667, India
Sharma, R., Wadia Institute of Himalayan Geology, Dehradun, 247 667, India
Srivastava, D.C., Indian Institute of Technology Roorkee, Roorkee, 247 667, India
Lister, G.S., Australian National University, Canberra, Australia
Funding Details: The authors thank Prof. A.K. Jain for his erudite suggestions. We thank the director of Wadia Institute of Himalayan Geology, Dehradun for allowing to use their Fluid Inclusion laboratory. We also thanks Mr. Rabinarayan from the Department of Architecture, IIT Roorkee for his help to develop the 3D models. This paper was written in memory of Marco Beltrando. DCS acknowledges the financial support from J. C. Bose Fellowship given by Department of Science and Technology, Government of India . Appendix A
Corresponding Author: Ojha, A.K.; Indian Institute of Technology RoorkeeIndia; email:
Appears in Collections:Journal Publications [ES]

Files in This Item:
There are no files associated with this item.
Show full item record

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.