Journal article
Crustally derived granites in Dali, SW China: new constraints on silicic magmatism of the Central Emeishan Large Igneous Province
International Journal of Earth Sciences, Vol.106(7), pp.2503-2525
10/2017
DOI: 10.1007/s00531-016-1444-7
Abstract
We have identified a new crustally derived granite pluton that is related to the Emeishan Large Igneous Province (ELIP). This pluton (the Wase pluton, near Dali) shows two distinct SHRIMP zircon U–Pb age groups (~768 and ~253 Ma). As it has an intrusive relationship with Devonian limestone, the younger age is interpreted as its formation, which is related to the ELIP event, whereas the ~768 Ma Neoproterozoic-aged zircons were inherited from Precambrian crustal component of the Yangtze Block, implying the pluton has a crustally derived origin. This is consistent with its peraluminous nature, negative Nb–Ta anomaly, enrichment in light rare earth elements, high 87Sr/86Sr(i) ratio (0.7159–0.7183) and extremely negative ε(Nd)(i) values (−12.15 to −13.70), indicative of melts derived from upper crust materials. The Wase pluton-intruded Devonian strata lie stratigraphically below the Shangcang ELIP sequence, which is the thickest volcanic sequence (~5400 m) in the whole ELIP. The uppermost level of the Shangcang sequence contains laterally restricted rhyolite. Although the rhyolite has the same age as the Wase pluton, its geochemical features demonstrate a different magma origin. The rhyolite displays moderate 87Sr/86Sr(i) (0.7053), slightly negative ε(Nd)(i) (−0.18) and depletions in Ba, Cs, Eu and Sr, implying derivation from differentiation of a mantle-derived mafic magma source. The coexistence of crustally and mantle-derived felsic systems, along with the robust development of dike swarms, vent proximal volcanics and thickest flood basalts piles in Dali, shows that the Dali area was probably where the most active Emeishan magmatism had once existed.
Details
- Title: Subtitle
- Crustally derived granites in Dali, SW China: new constraints on silicic magmatism of the Central Emeishan Large Igneous Province
- Creators
- Bei Zhu - School of Geoscience and Technology Southwest Petroleum University Chengdu 610500 Sichuan ChinaDavid Peate - Department of Earth and Environmental Sciences University of Iowa Iowa City IA 52242 USAZhaojie Guo - Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education, School of Earth and Space Sciences Peking University Beijing 100871 ChinaRunchao Liu - Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education, School of Earth and Space Sciences Peking University Beijing 100871 ChinaWei Du - Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education, School of Earth and Space Sciences Peking University Beijing 100871 China
- Resource Type
- Journal article
- Publication Details
- International Journal of Earth Sciences, Vol.106(7), pp.2503-2525
- Publisher
- Springer Berlin Heidelberg; Berlin/Heidelberg
- DOI
- 10.1007/s00531-016-1444-7
- ISSN
- 1437-3254
- eISSN
- 1437-3262
- Grant note
- No. 201699010090 / Young Scholars Development Fund of Southwest Petroleum University 41572199 / Natural Science Foundation of China
- Language
- English
- Date published
- 10/2017
- Academic Unit
- Earth and Environmental Sciences; Honors Program
- Record Identifier
- 9983983652602771
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