Petrographic and geochemical characteristic of volcanic rocks from Tasik Kenyir and Kampung Awah, East Malaya block, Peninsular Malaysia

Abstract

Kampung Awah and Tasik Kenyir are geologically located in East Malaya Blocks. These block is also known as western margin of Indochina terrane. Apart from sedimentary formations, East Malaya Blocks is also dominated by plutonic and volcanic rocks of mafic to rhyolitic compositions. Petrography and geochemical data suggest that Kampung Awah and Tasik Kenyir are one of locations which consists of volcanic rocks of generally basaltic to basaltic andesite compositions. Volcanic rocks from both area consists of plagioclcase, clinopyroxene, orthpyroxene as main mineral constituents with minor occurrences of hornblende. Geochemical data also indicate that volcanic rocks from both area were formed during subduction of the Paleo-tethys oceanic underneath the East Malaya Block or Indochina terrane. Most of the samples are metaluminous which indicate the volcanics are derived from igneous origin. This paper will contribute new geochemical data of mafic volcanics from Kampung Awah and Tasik Kenyir with the support of petrographic and field evidence to deduce the magma evolution and the tectonic setting.

Kepelbagaian Jenis Batuan di dalam Kompleks Stong Berdasarkan Cerapan Lapangan dan Kajian Petrografi

“…Di Semenanjung Malaysia, jarang dijumpai singkapan yang mempunyai kepelbagaian jenis batuan di dalam satu jasad granit. Kebanyakan singkapan seperti di Banjaran Titiwangsa mempunyai satu unit batuan yang dominan sahaja, iaitu granit dengan variasi saiz butiran daripada berbutir sederhana hingga kasar (Askury 1992(Askury , 1986Ghani 2009Ghani , 2000Ghani et al 2014, 2013, Muhammad Hatta et al 2018, 2016. Hanya beberapa jasad granit yang kompleks seperti di Benta, Gunung Stong dan Gunung Benom menunjukkan kepelbagaian jenis batuan igneus felsik dan mafik (Ghani 2002;Harbury et al 1990;Hutchison 1971Hutchison , 1969Jaafar Ahmad 1979;Mohd Rozi 1990;Mohd Rozi & Syed Sheikh 2000a, 2000bMohd Rozi & Hamzah 2001;Mohd Rozi et al 2001;Syed Sheikh 1994).…”