Earthquake triggered soft sediment deformational structures (seismites) in the Karewa formations of Kashmir valley–An indicator for palaeo-seismicity
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- 作者：Gulam Rasool Bhat ; Bikram S. Bali ; S. Balaji…
- 刊名：Journal of the Geological Society of India
- 出版年：2016
- 出版时间：April 2016
- 年：2016
- 卷：87
- 期：4
- 页码：439-452
- 全文大小：2,000 KB
- 刊物类别：Earth and Environmental Science
- 刊物主题：Geology
Geosciences
Geography
Mineralogy - 出版者：Springer India, co-published with Geological Society of India
- ISSN：0974-6889
- 卷排序：87
文摘
The intermontane Karewa basin contains a wide variety of seismically induced soft sediment deformation structures, interpreted as seismites and occurs in 1300 m thick succession of upper and lower Karewas. The Karewa Formation of Kashmir valley are glacio- fluvial-lacustrine and aeolian loess of Plio-Pleistocene age. The soft sediment deformational structures occurs in various formations and members of Karewas and vary greatly in terms of morphology and pattern. The Karewa Formations were frequently confronted with recurrent seismic activities during differential upliftment of Pir Panjal and Zanaskar ranges which resulted in various deformation structures during their evolution and development. In the present study, an attempt has been made to relate the palaeo-seismicity events in Karewa formations with the deformed structures of various formations. The origin of these deformational structures have been interpreted and analyzed from the field evidences by applying paleo-seismological approach. During and after the deposition of Karewas different soft sediment deformation structures (seismites) like load cast, convolute lamination, pseudonodules, recumbent folds, sand dykes etc. were formed during liquefaction and triggered by tectonic impulsive events. The deformational structures are evidenced by their unique nature, distribution, association, behaviour and deformation, and can be used as vital indicators for palaeo-seismicity.KeywordsPalaeo-seismicityKarewa formationsLiquefactionSeismitesEarthquake IndicatorsSoft sediment deformation structuresKashmir valley