Shock structures in Peninsular Malaysia: evidence from Kedah and Pahang

702001-100736-534-B
Author : H.D. Tjla & Mazlan Mohamad Zain
Publication : Bulletin of the Geological Society of Malaysia
Page : 103-110
Volume Number : 45
DOI : https://doi.org/10.7186/bgsm45200215

Bulletin of the Geological Society of Malaysia, Volume 45, May 2002, pp. 103 – 110

 

Shock structures in Peninsular Malaysia: evidence from Kedah and Pahang

H.D. Tjia1 and Mazlan Mohamad Zain2

1PETRONAS Research & Scientific Services, Lots 3288 & 3289 Off Jalan Ayer Itam, Bangi Institutional Estate, 43000 Kajang, Selangor

2Jabatan Mineral & Geosains Pahang, Aras 4 Wisma Persekutuan, Jalan Gambut, 25000 Kuantan, Pahang

 

Abstract: Evidence of geology, morphology and gravity anomalies demonstrate that the double Mahsuri Rings in Langkawi are impact structures. Each of the partially superimposed rings is 2.4 km across, with centres at 0.6 km distance apart and depths of 107 m (eastern ring) and 45 m. From these rings in the southwest direction are two more circular structures of progressively smaller size Temoyong and Tepor structures. Together the four structures probably represent the product of serial impacts of extraterrestrial projectiles arriving from the southwest. The impact event was post-granite of Gunung Raya (whose age is Triassic-Jurassic) if the topography was exhumed, but could be of Neogene age if the present landscape was never buried. The Paloh craters at the Pahang-Terengganu border are associated with vein quartz containing planar deformations features and display mosaicism. At Beserah near Kuantan, 35 km southeast from Bukit Paloh, quartz megacrysts of partially weathered granite show naturally etched cleavage. It is not yet clear if the PaIoh impact craters are in any way related to the shocked-metamorphose granitoids in the Kuantan area.

 

Abstrak: Ciri geologi, morfologi dan anomali graviti menandakan gelang kembar sekitar Makam Mahsuri ujud akibat hentaman benda langit. Setiap gelang bergaris-tengah 2.4 km dan pusatnya terletak 0.6 km pada arah 280°-110°. Gelang sebelah timur berkedalaman 107 meter manakala yang di sebelah baratnya mencapai kedalaman 45 meter. Dari Gegelang Mahsuri ke arah barat daya didapati dua gelang lain yang bersaiz semakin kecil, iaitu Temoyong dan Tepor. Keempat struktur dicadangkan mewakili suatu siri hentaman oleh sekumpulan bendalangit yang datang dari arah barat daya. Hentaman terjadi selepas terobosan granitoid Gunung Raya, iaitu lepas Trias-Jura jika landskap gegelang pernah tertimbus dan tersingkap semula. Jika topografi tidak pernah dilindungi oleh sedimen muda, kejadian hentaman boleh lebih muda daripada Neogen. Kawah-kawah Paloh di sempadan negeri Pahang-Terengganu bersekutu dengan kuarza telerang yang memiliki ira halus (PDF) serta pemadaman mosaik. Di Beserah berhampiran Kuantan, 35 km ke sebelah tenggara Bukit PaIoh, didapati megakris kuarza daripada granit separa terluluhawa memiliki ira terukir semulajadi. Setakat ini masih kurang jelas sama ada kawah-kawah hentaman Paloh mempunyai kaitan dengan fitur hentaman yang dipamerkan oleh kuarza dalam granit di kawasan Kuantan.

https://doi.org/10.7186/bgsm45200215