Bulletin of the Geological Society of Malaysia, Volume 49, April 2004, pp. 61 – 65

Fasies karbonat dan diagenesis di dalam batu kapur Bukit Biwah dan Bukit Taat, Kenyir, Ulu Terengganu

CHE AZIZ ALI, MOHD. SHAFEEA LEMAN & KAMAL ROSLAN MOHAMED

Pusat Pengajian Sains Sekitaran dan Sumber Alam, Fakulti Sains dan Teknologi, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor

Abstrak: Batu kapur Bukit Biwah dan Taat yang terletak di Tasik Kenyir, Terengganu mewakili unit batu kapur yang terbentuk di zaman Perm. Komposisi batu kapur ini terdiri daripada batu lumpur, batu wak dan batu padat dengan sedikit batu butir. Butiran utama terdiri daripada kerangka organisma laut cetek (algae, foraminifera, bryozoa, fusulinid, brakiopod, bivalvia, gastropod dan karang). Sebahagian lagi daripada butiran dibentuk oleh bahan-bahan peloid. Batuan ini telah melalui beberapa tahap proses diagenesis yang melibatkan penyimenan semasa sedimen berada di dasar laut dan juga penyimenan yang telah berlaku selepas batuan tertimbus dalam. Di samping itu pendolomitan juga sangat lazim namun ianya tidak membentuk isipadu yang besar di dalam batuan. Kehadiran stilolit minor dan beramplitud rendah dan lipit perlarutan menunjukkan bahawa batuan tersebut tidak mengalami tekanan dan tegasan yang kuat.

Abstract: Limestones of Bukit Biwah and Bukit Taat, Kenyir Lake, Terengganu represent a limestone unit that was deposited during the Middle Permian. The limestone is made up of mudstone, wackestone and packstone with subordinate grainstone. The dominant grains comprise tests and shells of shallow marine organisms that dwelled on the sea bottom during the Permian (algae, foraminifera, bryozoa, fusulines, brachiopod, bivalve, gastropod and coral). Some other grains are made up of peloidal material. The rock has undergone several diagenetic processes including surface or near surface cementation when the sediment was at the sea bottom and also late burial cementation. Apart from that dolomitization seems to be very common though not pervasive. The presence of minor low amplitude stylolites and dissolution seams indicate that the rock unit has not experienced extreme pressure and deformation.

https://doi.org/10.7186/bgsm49200411