Abstract
The Qiangtang metamorphic belt (QMB) in central Tibet is one of the largest and most recently documented high-pressure (HP) to near-ultrahigh-pressure (near-UHP) belts on Earth. Lu-Hf ages of eclogite- and blueschist-facies rocks within the QNB an 244-223 Ma, indistinguishable from the age of UHP metamorphism in the Qinling-Dabie orogen. Results of a U-Pb detrital zircon study suggest that protoliths of the QMB include upper Paleozoic Qiangtang continental margin strata and sandstones that were derived from a Paleozoic arc terrane that developed within the Paleo-Tethys Ocean to the north. We attribute QMB HP metamorphism to continental collision between the Qiangtang terrane and a Paleo-Tethys arc terrane. This collision, and the coeval South China-North China collision, may have slowed convergence between Laurasia and Gondwana-derived terranes and initiated Mediterranean-style rollback and backarc basin development within much of the remnant Paleo-Tethys Ocean realm.
Original language | English (US) |
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Pages (from-to) | 351-354 |
Number of pages | 4 |
Journal | Geology |
Volume | 36 |
Issue number | 5 |
DOIs | |
State | Published - May 2008 |
Keywords
- Continental subduction
- Eclogite
- Paleo-tethys
- Qiangtang
- Rollback
- Tibet
ASJC Scopus subject areas
- Geology