K:Ar ages and geochemistry of the Sabah Cenozoic volcanic rocks

Author : Steven C. Bergman, Charles S. Hutchison, David A. Swauger and John E. Graves
Publication : Bulletin of the Geological Society of Malaysia
Page : 165-171
Volume Number : 44
Year : 2000
DOI : https://doi.org/10.7186/bgsm44200021

Bulletin of the Geological Society of Malaysia, Volume 44, July 2000, pp. 165 – 171

K:Ar ages and geochemistry of the Sabah Cenozoic volcanic rocks

1Steven C. Bergman, 2Charles S. Hutchison, 1David A. Swauger and 1John E. Graves

1Arco International Oil and Gas Company and Arco Exploration & Production Technology, 2300 W. Plano Pkwy., Plano, Texas 75075-8499, U.S.A.

210 Lorong 5/19A, 46000 Petaling Jaya, Selangor, Malaysia


Abstract: K-Ar dates for volcanic rocks of the southern Dent Peninsula confirm a Middle Miocene age, and K-Ar dates on the Semporna Peninsula also indicate a similar Middle Miocene age, older than previously held.

The Pliocene rift-related subaerial basalts of the Mostyn Estate of the Kunak area are of the low-K tholeiite series and also display MORB characteristics, indicating a rift-related magma genesis resulting in partial melting of an identical source to the Mesozoic ophiolite of the Segama area.

The Miocene volcanic rocks of the Semporna and southern Dent Peninsulas, by contrast, have calc-alkaline affinities and their trace element geochemistry indicates a subduction related genesis with typical enrichment in the light rare earth elements.