. | . |
When did India collide with Asia to form the Himalayan mountains by Staff Writers Beijing, China (SPX) Apr 04, 2017
The collision between the Indian subcontinent and the Asian landmass resulted in the formation of the Himalayan Mountains and the rise of the Tibetan Plateau, with consequent major climatic and environmental changes around our planet. Placing precise constraints on the timing of the India-Asia continental collision is essential to understand the subsequent geological and topographic evolution of the orogenic belt as well as the tectonic uplift of the Tibetan Plateau and their effects on climate, environment, and life. A recent study has constrained precisely the timing of the initial India-Asia continental collision by the accurate analysis of the sedimentary record preserved along the collision zone. The related research, entitled "Constraining the timing of the India-Asia continental collision by the sedimentary record", has just been published as a cover article in Issue 4, Volume 60 of SCIENCE CHINA Earth Sciences 2017, in both Chinese and English, with Professor Xiumian Hu from Nanjing University as first and corresponding author. Based on the detailed study of fossils and detrital minerals contained in strata exposed along both sides of the Yarlung-Zangbo suture zone in Tibet, a team of Chinese and Italian researchers has determined with unprecedented accuracy the time when India and Asia first came into contact by pin-pointing major changes of sedimentary style and in provenance of detritus. A variety of approaches have been followed to date such a major tectonic event, including paleomagnetism and biostratigraphic or radiometric dating of sedimentary, magmatic and metamorphic rocks coupled with structural, stratigraphic and sedimentological observations. A fierce debate ensued often because different research teams used different indicators and criteria to define continental collision and tentatively assess the chronological sequence of progressing orogeny. This new research starts from a clear definition of collision onset as the timing of first contact between the opposite edges of the Indian and Asian continental crusts following complete consumption of intervening Neo-Tethyan oceanic lithosphere at a point. By accurately dating with multiple methods the turbiditic deep-sea sediments derived from both India and Asia and deposited in the trench just south of the zone of initial collision, the researchers have constrained precisely the India-Asia collision onset as middle Palaeocene (59+/-1 million years ago). Initial continent-continent collision preceded by 20 million years the final disappearance of marine seaways from the Himalayas, and by 30 million years the accumulation of massive fluvial gravel and sand deposits in the Indo-Gangetic plain of northern India. Researchers also show that there was no major diachroneity of collision onset from the central to the western Himalaya. This study represents a major contribution to understand plate tectonics and continental dynamics, and is of great significance not only as far as the India-Asia collision, Himalayan orogeny, Tibetan-Plateau uplift and consequent Cenozoic climatic change are concerned, but also because it provides a reference standard useful to investigate the process of continental collision and to reconstruct its progress in time resulting in the full growth of huge mountain belts. Hu XM, Wang JG, An W, Garzanti E, Li J, 2017. Constraining the timing of the India-Asia continental collision by the sedimentary record. Science China Earth Sciences, 60: 603-625, doi: 10.1007/s11430-016-9003-6
Seattle WA (SPX) Mar 30, 2017 Stock traders have long used specialized trackers to decide when to buy or sell a stock, or when the market is beginning to make a sudden swing. A new University of Washington study finds that the same technique can be used to detect gradual movement of tectonic plates, what are called "slow slip" earthquakes. These movements do not unleash damaging amounts of seismic energy, but scientists are ... read more Related Links Science China Press Tectonic Science and News
|
|
The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us. |