Journal articles
Syn-collisional channel flow and exhumation of paleoproterozoic High Pressure rocks in the Trans-North China Orogen: the critical role of partial-melting and orogenic bending
Abstract : Within the paleoproterozoic Trans-North China Orogen, the High-Pressure Belt (HPB) is made of high-pressure (~ 15 kbar) mafic granulites hosted in migmatitic gneisses. In this contribution, we document a set of structural analyses acquired over the whole HPB. We also proposed a morphological subdivision of the partially molten rocks that compose the HPB according to changes in melt fraction. A compilation of the P-T and radiochronological data carried out over the last 15 years is presented. The results highlight the concurrent effect of oroclinal bending and partial-melting in controlling the exhumation of the deeply buried continental crust. During ongoing compression of the thickening orogenic root, onset of partial-melting at peak metamorphism is responsible for a first strength drop that enhanced an eastward lateral flow. Radiometric ages show that the deep crust was partially molten over a 50 Ma lasting period during which it evolved in a diatexite core mantled by metatexites. This was responsible for a second strength drop with strain concentrated along the diatexite/metatexite boundaries, as exemplified by the newly documented Datong-Chengde Shear Zone, a ~ 400 km-long normal shear zone with a sinistral strike-slip component that accommodated the final uprise of the high-pressure rocks.
Cited literature [87 references]
https://hal-insu.archives-ouvertes.fr/insu-00576322
Contributor : Nathalie Pothier Connect in order to contact the contributor
Submitted on : Friday, June 24, 2011 - 11:17:39 AM
Last modification on : Tuesday, October 19, 2021 - 7:01:25 PM
Long-term archiving on: : Sunday, September 25, 2011 - 2:20:08 AM
Contributor : Nathalie Pothier Connect in order to contact the contributor
Submitted on : Friday, June 24, 2011 - 11:17:39 AM
Last modification on : Tuesday, October 19, 2021 - 7:01:25 PM
Long-term archiving on: : Sunday, September 25, 2011 - 2:20:08 AM
File
TrapP-GR.pdf
Files produced by the author(s)