Pliocene-Quaternary crustal melting in central and northern Tibet and insights into crustal flow.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 27307135.
- Also identified by DOI 10.1038/ncomms11888 and PMC identifier 4912662.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
There is considerable controversy over the nature of geophysically recognized low-velocity-high-conductivity zones (LV-HCZs) within the Tibetan crust, and their role in models for the development of the Tibetan Plateau. Here we report petrological and geochemical data on magmas erupted 4.7-0.3 Myr ago in central and northern Tibet, demonstrating that they were generated by partial melting of crustal rocks at temperatures of 700-1,050 °C and pressures of 0.5-1.5 GPa. Thus Pliocene-Quaternary melting of crustal rocks occurred at depths of 15-50 km in areas where the LV-HCZs have been recognized. This provides new petrological evidence that the LV-HCZs are sources of partial melt. It is inferred that crustal melting played a key role in triggering crustal weakening and outward crustal flow in the expansion of the Tibetan Plateau.