Wang, Yuejun and Qian, Xin and Cawood, Peter A. and Abdul Ghani, Azman and Gan, Chengshi and Wu, Sainan and Zhang, Yuzhi and Wang, Yang and Zhang, Peizhen (2022) Cretaceous Tethyan subduction in SE Borneo: Geochronological and geochemical constraints from the igneous rocks in the Meratus Complex. Journal of Asian Earth Sciences, 226. ISSN 1367-9120, DOI https://doi.org/10.1016/j.jseaes.2022.105084.
Full text not available from this repository.Abstract
SE Borneo lies at the junction of the Pacific and Tethyan realms. The Mesozoic geological record of the region is dominated by convergent plate margin activity, although the geological details and its broader role in the SE Asia evolution are poorly documented. This paper presents geochronological, whole-rock elemental and Sr-Nd-Pb isotopic data on the igneous rocks from the Meratus Complex in SE Borneo. The Meratus ophiolite might form at the Late Jurassic-Early Cretaceous (similar to 150-115 Ma), and the spatially-associated Haruyan Volcanics, Bela-wayan granitoids and their equivalents generated in the Early Cretaceous (similar to 140-107 Ma). The Haruyan and Pitap formations and their equivalents are dominated by Early Cretaceous (similar to 140-115 Ma) volcanic rocks and late Early Cretaceous (similar to 115-100 Ma) siliciclastic rocks, respectively. The mafic-intermediate igneous rocks in the Meratus Complex are characterized by MgO = 2.04-13.20 wt%, TiO2 = 0.48-1.51 wt%, Nb/La = 0.09-0.42, epsilon(Nd)(t) = +4.6-+7.7, (Pb-206/Pb-204)(i) = 18.15-18.61, (Pb-207/Pb-204)(i) = 15.41-15.63 and (Pb-208/Pb-204)(i) = 38.03-38.63, and originated from the slab-related mantle wedge. The granitoids share similar elemental ratios and Sr-Nd-Pb isotopic compositions with the coeval mafic rocks, with Nb/La = 0.20-0.30, epsilon(Nd)(t) = +4.8-+6.0, Delta 8/4 = 26.2-38.8 and Delta 7/4 = 5.0-7.7, representing the products of the wedge-originated juvenile crust. Synthesis of all data reveals a NW-Australian affinity for SE Borneo. The Early Cretaceous fore-arc tectonic setting extends southerly into the Bantimala (SW Sulawesi) and Luk Ulo (Central Java), constituting a united Early Cretaceous Central Indonesian accretionary zone. The Meratus Ocean subducted beneath the Argo frag-ment since-140 Ma and likely assembled with the Sundaland margin at-100 Ma in response to the Neotethyan consumption.
| Item Type: | Article |
|---|---|
| Funders: | National Natural Science Foundation of China (NSFC) [Grant No: 41830211; U1701641; 42002236], Natural Science and R&D Foundation of Guangdong Province, China [Grant No: 2016ZT06N331; 2018B030312007; 2019B1515120019], Australian Research Council [Grant No: FL160100168] |
| Uncontrolled Keywords: | Zircon U-Pb dating; Elemental and isotopic compositions; Igneous rocks; Meratus complex; Neotethyan subduction; Australian affinity; SE Borneo |
| Subjects: | Q Science > QE Geology |
| Divisions: | Faculty of Science > Department of Geology |
| Depositing User: | Ms. Juhaida Abd Rahim |
| Date Deposited: | 05 Sep 2023 08:28 |
| Last Modified: | 05 Sep 2023 08:28 |
| URI: | http://eprints.um.edu.my/id/eprint/43072 |
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