Significance of radiolarian cherts from the Chert-Spilite Formation, Telupid, Sabah

702001-101048-850-B
Author : Basir Jasin
Publication : Bulletin of the Geological Society of Malaysia
Page : 67-83
Volume Number : 31
DOI : https://doi.org/10.7186/bgsm31199205

Bulletin of the Geological Society of Malaysia, Volume 31, July 1992, pp. 67 – 83

 

Significance of radiolarian cherts from the Chert-Spilite Formation, Telupid, Sabah

BASIR JASIN

Jabatan Geologi, Universiti Kebangsaan Malaysia

 

Abstract: Chert in Telupid area is found associated with basalt, serpentinite and peridotite. This rock association may represent a part of the ophiolite sequence. The chert occurs as thinly bedded chert interbeds with siliceous shale. The chert is red to reddish brown in colour. The chert contains abundant skeletons of radiolaria. The radiolaria were retrieved, from their siliceous matrix by leaching with hydrofluoric acid. Several species of radiolaria were identified and their age was determined. Geochemical analysis of bedded radiolarian chert exhibits very high percentage of silica (more than 75%). Most of the chert consists of biogenic silica. The low content of AI2O3 and CaO suggests that the chert was deposited very far away from sources of terigenous detritus and below the calcite compensation depth. 

 

Abstrak: Rijang di kawasan Telupid didapati berasosiasi dengan basalt, serpentinit dan peridotit. Asosiasi batuan ini mewakili sebahagian jujukan ofiolit. Rijang ini wujud sebagai lapisan nipis yang berselang ,lapis dengan syal bersilika. Rijang ini berwarna merah hingga merah-perang. Rijang mengandungi kelimpahan rangka radiolaria. Radiolaria dikeluarkan daripada matrik silika dengan melarutkan dalam asid hidrofluorik. Beberapa spesies radiolaria dikenalpasti dan usia telah ditentukan. Analisis geokimia lapisan rijang berradiolaria menunjukkan peratusan silika yang tinggi (lebih 75%), kebanyakannya terdiri daripada silika biogen. Kandungan AI2O3 dan CaO yang rendah mencadangkan rijang ini diendapkan jauh daripada punca gersik terigen dan diendapkan di bawah kedalaman pampasan kalsit. 

https://doi.org/10.7186/bgsm31199205