Late Paleozoic to Mesozoic extension in southwestern Fujian Province, South China: Geochemical, geochronological and Hf isotopic constraints from basic-intermediate dykes
| Autor: | Haibin Feng, Absai Vatuva, Shuai Ma, Da Zhang, Yongjun Di, Ganguo Wu, Sen Wang, Pengcheng Yan |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Paleozoic
020209 energy lcsh:QE1-996.5 Earth and Planetary Sciences(all) 02 engineering and technology Southwestern Fujian 010502 geochemistry & geophysics Extensional tectonics 01 natural sciences Cretaceous Diabase lcsh:Geology Carboniferous 0202 electrical engineering electronic engineering information engineering Intraplate earthquake General Earth and Planetary Sciences Late Paleozoic Late Devonian extinction Mesozoic Petrology Geology 0105 earth and related environmental sciences Zircon |
| Zdroj: | Geoscience Frontiers, Vol 8, Iss 3, Pp 529-540 (2017) |
| ISSN: | 1674-9871 |
| Popis: | The tectonic evolution of SE China block since late Paleozoic remains debated. Here we present a new set of zircon U-Pb geochronological, Lu-Hf isotopic data and whole-rock geochemistry for two stages of basic-intermediate dykes from the southwestern Fujian. The samples were collected from the NE-trending (mainly diabases) and NW-trending (mainly diabasic diorites) dykes and yielded zircon U-Pb ages of 315 and 141 Ma, with e Hf ( t ) values of −8.90 to 7.49 and −23.39 to −7.15 (corresponding to T DM2 values of 850 to 1890 Ma and 737 to 2670 Ma), respectively. Geochemically these rocks are characterized by low TiO 2 (0.91–1.73 wt.%) and MgO (3.04–7.96 wt.%), and high Al 2 O 3 (12.5–16.60 wt.%) and K 2 O (0.60–3.63 wt.%). Further they are enriched in LREEs and LILEs (Rb, Ba, Th and K), but depleted in HFSEs (Nb, Ta and Zr). The tectonic discrimination analysis revealed that the dykes were formed in an intraplate extensional environment. However, the NW trending dykes show crust-mantle mixed composition, which indicate an extensional tectonic setting with evidence for crustal contamination. The SE China block experienced two main stages of extensional tectonics from late Carboniferous to early Cretaceous. The tectonic evolution of the SE China block from late Devonian to Cretaceous is also evaluated. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|