کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5786073 | 1640333 | 2017 | 14 صفحه PDF | دانلود رایگان |
- The geochemistry and Nd isotope data of Bangka plutons show Main Range affinity.
- The plutons on Bangka were emplaced within the period of Main Range magmatism.
- They were emplaced at ca. 225Â Ma on the NE of Bangka and at ca. 220Â Ma on the SW.
- The unexposed Paleo-Tethyan suture is inferred therefore to lie to the east.
The South-East Asian Tin Belt is one of the most tin-productive regions in the world. It comprises three north-south oriented granite provinces, of which the arc-related Eastern granite province and the collision-related Main Range granite province run across Thailand, Singapore, and Indonesia. These tin-producing granite provinces with different mineral assemblages are separated by Paleo-Tethyan sutures exposed in Thailand and Malaysia. The Eastern Province is usually characterised by granites with biotite ± hornblende. Main Range granites are sometimes characterised by the presence of biotite ± muscovite. However, the physical boundary between the two types of granite is not well-defined on the Indonesian Tin Islands, because the Paleo-Tethyan suture is not exposed on land there. Both hornblende-bearing (previously interpreted as I-type) and hornblende-barren (previously interpreted as S-type) granites are apparently randomly distributed on the Indonesian Tin Islands. Granites exposed on Bangka, the largest and southernmost Tin Island, no matter whether they are hornblende-bearing or hornblende-barren, are geochemically similar to Malaysian Main Range granites. The average ÉNd(t) value obtained from the granites from Bangka (average ÉNd(t) = â8.2) falls within the range of the Main Range Province (â9.6 to â5.4). These granites have SIMS zircon U-Pb ages of ca. 225 Ma and ca. 220 Ma, respectively that are both within the period of Main Range magmatism (â¼226-201 Ma) in the Peninsular Malaysia. We suggest that the granites exposed on Bangka represent the continuation of the Main Range Province, and that the Paleo-Tethyan suture lies to the east of the island.
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Journal: Journal of Asian Earth Sciences - Volume 138, 1 May 2017, Pages 548-561