Bulletin of the Geological Society of Malaysia, Volume 39, July 1996, pp. 65 – 80

Petrology and geochemistry of the volcanic rocks associated with the Darvel Bay Ophiolite, Lahad Datu, eastern Sabah, Malaysia

SHARIFF A.K. OMANG

Jabatan Sains Bumi, FSSA, Universiti Kebangsaan Malaysia Kampus Sabah, Beg Berkunci No. 62, 88996 Kota Kinabalu, Sabah, Malaysia

Abstract: Field observation, petrographic description and bulk rock geochemistry investigation suggest the presence of at least three, genetically unrelated, volcanic rock groups in the ophiolitic terrain of the Darvel Bay area. Group I Darvel Bay volcanic rocks are of the ocean island alkali basalt (OIB_A) origin, characterised by LREE enrichment and abundance in HFSE (Zr, Ti). Group II Darvel Bay volcanic rocks have a chemistry similar to those of N-MORB on the basis of depleted LREE and abundance of compatible elements (Ni, Cr, Sc). Group III Darvel Bay volcanic rocks are characterised by LlLE and LREE enrichment, and have a depletion in compatible elements (Ni, Cr) and HFSE (Nb, Ti), indicating that they may have originally been erupted in an island arc setting.

Group I and II Darvel Bay volcanic rocks may be related to the volcanic activity during formation of the oceanic crust. Group III Darvel Bay volcanic rocks may be related to the Middle Miocene volcanic arc activity of the Dent Peninsula, SE Sabah.

https://doi.org/10.7186/bgsm39199607