Mafic microgranular enclaves (MMEs) in amphibole-bearing granites of the Bintang batholith, Main Range granite provinceEvidence for a meta-igneous basement in Western Peninsular Malaysia

Long Xiang Quek*, Azman A. Ghani, Sun Lin Chung, Shan Li, Yu Ming Lai, Mokhtar Saidin, Meor H. Amir Hassan, Muhammad Afiq Muhammad Ali, Muhammad Hafifi Badruldin, Ahmad Farid Abu Bakar

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)

Abstract

Mafic microgranular enclaves (MMEs) with varying sizes are a common occurrence in porphyritic amphibole-bearing granite of the Bintang batholith, which is part of the Main Range granite province. The MMEs of the amphibole-bearing granite are significant as they are related to the I-type granitoids within the Main Range granite province. Petrographic observations indicate the MMEs are mantled with coarse mafic crystals on the rim and contain similar minerals to the host (biotite + plagioclase + K-feldspar + pyroxene + amphibole), but in different proportions. Geochemical analyses indicate the MMEs are shoshonitic with mg# comparable to the granite host. Substantial similarities exist between the MMEs and granite with regards to the normalized rare earth element patterns and trace elements variation diagrams. The MMEs and granite are not completely coeval as the MME zircon U-Pb age (224.3 ± 1.2 Ma) is slightly older than its granite host zircon U-Pb age (216.2 ± 1.0 Ma). The age difference is also observed from the unusual 500 m-long Tiak MME and another amphibole-bearing granite sample from the south of the pluton, which yield 221.8 ± 1.1 Ma and 217.4 ± 1.0 Ma respectively. The oldest inherited zircons found in the MME and granite are 2.0 Ga and 1.3 Ga respectively, while the oldest xenocrystic zircons found in the MME and granite are 2.5 Ga and 1.5 Ga respectively. Identical negative εHf(t) values from zircon U-Pb and Lu-Hf analysis for a MME-granite pair indicates the rocks were generated from a similar, ancient source in the basement. Combining the results, we suggest that incongruent melting of an ancient protolith played an important part in the evolution of the MMEs and granite and the MMEs characteristics are best explained as restite. The zircon Hf model age (two-stage) and the I-type peritectic and restitic mineral assemblages in the MMEs further describe the protolith as Early Proterozoic-Late Archean (≈2.5 Ga) meta-igneous rock. This shows the Western Peninsular Malaysia basement does not consist entirely of meta-sedimentary rocks. As the amphibole-bearing granite and MMEs ages both falls within the suggested period of Late Triassic Sibumasu and Indochina-East Malaya collision and the calculated melt temperature for the amphibole-bearing granite is much higher than melt generated from a sedimentary source, the high heat flow required for protolith melting is best explained by episodes of lithosphere attenuation during the collision. The age of the MME and Tiak MME (∼221–224 Ma) can be taken to indicate the time of such an event.

Original languageEnglish
Pages (from-to)11-29
Number of pages19
JournalJournal of Asian Earth Sciences
Volume143
DOIs
Publication statusPublished - 2017 Aug 1

Keywords

  • I-type granitoid
  • Late Triassic Sibumasu Terrane and Indochina-East Malaya Block collision
  • Mafic microgranular enclaves
  • Peninsular Malaysia Main Range granite province
  • Peritectic mineral assemblages
  • Western Peninsular Malaysia basement

ASJC Scopus subject areas

  • Geology
  • Earth-Surface Processes

Fingerprint

Dive into the research topics of 'Mafic microgranular enclaves (MMEs) in amphibole-bearing granites of the Bintang batholith, Main Range granite provinceEvidence for a meta-igneous basement in Western Peninsular Malaysia'. Together they form a unique fingerprint.

Cite this