Struktur dan sejarah canggaan batuan di Pulau Kapas, Terengganu

702001-100682-490-B
Author : Ibrahim Abdullah
Publication : Bulletin of the Geological Society of Malaysia
Page : 345-350
Volume Number : 45
DOI : https://doi.org/10.7186/bgsm45200254

Bulletin of the Geological Society of Malaysia, Volume 45, May 2002, pp. 345 - 350

 

Struktur dan sejarah canggaan batuan di Pulau Kapas, Terengganu

(Structure and deformation history of rocks in Pulau Kapas, Terengganu)

Ibrahim Abdullah

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

 

Abstrak: Batuan metasedimen bergred rendah berusia Karbon di Pulau Kapas telah mengalami canggaan yang menghasilkan lipatan ketat menunjam ke arah selatan-tenggara (STG) atau utara-baratlaut (UBL). Pada zon tertentu terdapat lipatan ketat yang terbalik disempadani oleh sesar songsang atau sungkup. Sungkupan ke arah barat-baratdaya adalah yang dominan, manakala ke timur-timurlaut ditafsirkan sebagai sungkup-belakang. Canggaan seterusnya menghasilkan sesaran mendatar dekstral berarah hampir utara-selatan yang turut melibatkan konglomerat yang ditafsirkan berusia Perm. Sistem tegasan dengan mampatan arah timur-timurlaut sekali lagi dialami oleh kawasan ini, menerbitkan sesaran mendatar dekstral dan sinistral yang diakhiri dengan rejahan daik dolerit. Sistem tegasan dengan mampatan dari arah tenggara-baratlaut mengakhiri canggaan kawasan ini yang menerbitkan sesaran hampir utara-selatan dengan gerakan sinistral. Sistem tegasan ini juga telah mengaktifkan semula sesar utara-selatan yang sudah sedia wujud dengan gerakan sinistral.

 

Abstract: The Carboniferous low grade metasedimentary rocks in Pulau Kapas have suffered deformation that produced tight folds plunging towards north-northwest (NNW) or south-southeast (SSE). Within certain zones, the tight folds are overturned and bounded by reverse or thrust faults. The thrusting towards west-southwest (WSW) are dominant while towards east-northeast (ENE) are interpreted as a result of backthrust. The following deformation was responsible for the developments of the dextral north-south faults which also cut the supposed Permian conglomerate in the area. Subsequently, the area was affected by a compression from east-northeast, resulting in the formation of dextral and sinistral lateral faults followed by the intrusion of dolerite dyke trending about ENE. Lastly a stress system with a southeast-northwest compression produced almost north-south sinistral lateral fault displacing the ENE dyke. This stress system was also responsible for the reactivation of movement on the pre-existing north-south faults.

https://doi.org/10.7186/bgsm45200254