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Age and composition of dikes in Southern Tibet: New constraints on the timing of east-west extension and its relationship to postcollisional volcanism

2001; Geological Society of America; Volume: 29; Issue: 4 Linguagem: Inglês

10.1130/0091-7613(2001)029 2.0.co;2

1943-2682

Helen M. Williams, Simon Turner, S. P. Kelley, Nigel Harris,

Geological Studies and Exploration

Research Article| April 01, 2001 Age and composition of dikes in Southern Tibet: New constraints on the timing of east-west extension and its relationship to postcollisional volcanism Helen Williams; Helen Williams 1Department of Earth Sciences, The Open University, Milton Keynes MK7 6AA, UK Search for other works by this author on: GSW Google Scholar Simon Turner; Simon Turner 1Department of Earth Sciences, The Open University, Milton Keynes MK7 6AA, UK Search for other works by this author on: GSW Google Scholar Simon Kelley; Simon Kelley 1Department of Earth Sciences, The Open University, Milton Keynes MK7 6AA, UK Search for other works by this author on: GSW Google Scholar Nigel Harris Nigel Harris 1Department of Earth Sciences, The Open University, Milton Keynes MK7 6AA, UK Search for other works by this author on: GSW Google Scholar Author and Article Information Helen Williams 1Department of Earth Sciences, The Open University, Milton Keynes MK7 6AA, UK Simon Turner 1Department of Earth Sciences, The Open University, Milton Keynes MK7 6AA, UK Simon Kelley 1Department of Earth Sciences, The Open University, Milton Keynes MK7 6AA, UK Nigel Harris 1Department of Earth Sciences, The Open University, Milton Keynes MK7 6AA, UK Publisher: Geological Society of America Received: 24 Jul 2000 Revision Received: 20 Dec 2000 Accepted: 29 Dec 2000 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2001) 29 (4): 339–342. https://doi.org/10.1130/0091-7613(2001)029 2.0.CO;2 Article history Received: 24 Jul 2000 Revision Received: 20 Dec 2000 Accepted: 29 Dec 2000 First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Helen Williams, Simon Turner, Simon Kelley, Nigel Harris; Age and composition of dikes in Southern Tibet: New constraints on the timing of east-west extension and its relationship to postcollisional volcanism. Geology 2001;; 29 (4): 339–342. doi: https://doi.org/10.1130/0091-7613(2001)029 2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Controversy exists over whether east-west extension in southern Tibet is related to plateau uplift or to the accommodation of plate boundary forces. Relationships between the onset of extension, plateau uplift, and the thermal state of the lithosphere are critical to this debate. We present new data on postcollisional, north-south–trending dikes in southern Tibet. Their ages range from 18.3 ± 2.7 Ma to 13.3 ± 0.8 Ma, and define the onset of regional east-west extension in southern Tibet. Dikes are compositionally indistinguishable from postcollisional lavas in southern Tibet, being either ultrapotassic, having a source in the subcontinental lithospheric mantle, or calc-alkaline with a dominantly crustal origin. The ultrapotassic dikes demonstrate that east-west extension and subcontinental lithospheric mantle–derived magmatism were temporally and spatially linked, supporting models that relate the latest phase of plateau uplift to subcontinental lithospheric mantle thinning. Thus, the onset of extension by 18.3 ± 2.7 Ma represents the time at which the potential energy of the plateau exceeded convergent boundary forces. This places a new age limitation on the attainment of high elevation in southern Tibet, with implications for models that relate Cenozoic monsoon intensification to plateau uplift. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.