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A Precambrian trondhjemite boulder in Palaeozoic mudstones of NW Malaya

Published online by Cambridge University Press:  01 May 2009

P. H. Stauffer  and
N. J. Snelling
P. H. Stauffer
Affiliation:
Department of Geology, University of Malaya, Kuala Lumpur, Malaysia
N. J. Snelling
Affiliation:
Institute of Geological Sciences, London
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Summary

A boulder of plutonic igneous rock, petrologically perhaps best termed a trondhjemite, which occurs as an isolated megaclast in slumped mudstones of the Singa Formation (mainly Carboniferous) at Pulau Tepor off NW Malaya, has been dated by the potassium–argon method. Two feldspar fractions, thought to represent alkali feldspar and plagioclase (though both are highly sodic) yield ages of 1029±15 Ma and 575±10 Ma, respectively, while a whole-rock sample yields an age of 264±4 Ma. The highest age is taken to give a minimum age for the rock, and the lower ages to indicate differential argon loss. This is the first radiometrically proved Precambrian rock from the Malay Peninsula, and tends to reinforce earlier inferences of a Precambrian continent as a source area for Palaeozoic sediments in the region.

Type
Articles
Information
Geological Magazine , Volume 114 , Issue 6 , November 1977 , pp. 479 - 482
Copyright
Copyright © Cambridge University Press 1977

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References

Jantan, Ahmad bin. 1973. Stratigraphy of the Singa Formation (Upper Paleozoic) in the southwestern part of the Langkawi Island Group, West Malaysia. M. Sc. Thesis. Apply to University of Malaya, Kuala Lumpur.Google Scholar
Baum, F. et al. 1970. On the geology of Northern Thailand. Beih. geol. Jb. (Hannover) 102.Google Scholar
Garson, M. S. et al. 1975. The geology of the tin belt in Peninsular Thailand around Phuket, Phangnga and Takua Pa. Overseas Mem. Inst. geol. Sci. 1.Google Scholar
Gobbett, D. J. 1973. Upper Paleozoic. In Geology of the Malay Peninsula (West Malaysia and Singapore) (ed. Gobbett, D. J. and Hutchison, C. S.), pp. 61–95. New York: Wiley-Interscience.Google Scholar
Jones, C. R. 1966. Geological Map of Pulau Langkawi (New Series Sheet 150), 1:63,360. Geol. Surv. Malaysia.Google Scholar
Jones, C. R. 1966MS. Geology and mineral resources of Perlis, north Kedah and the Langkawi Islands, Malaya. To be published as Mem. geol. Surv. Dep. Malaysia.Google Scholar
Jones, C. R. 1968. Lower Paleozoic rocks of Malay Peninsula. Bull. Am. Ass. Petrol. Geol. 52, 1259–78.Google Scholar
Stauffer, P. H. 1974 a. Malaya and Southeast Asia in the pattern of continental drift. Bull. geol. Soc. Malaysia 7, 89–138.CrossRefGoogle Scholar
Stauffer, P. H. 1974 b. (Abstr.) Petrology of some Malayan conglomerates and their implications. Newsletter geol. Soc. Malaysia 47, 7–8.Google Scholar
Stewart, D. B. 1975. Lattice parameters, composition and Al/Si order in alkali feldspars. In Feldspar Mineralogy (ed. Ribbe, P. H.). Mineralogical Society of America Short Course Notes, vol. 2, St. 1–St. 22.Google Scholar
Yancey, T. E. 1975. Evidence against Devonian unconformity and middle Paleozoic age of Langkawi folding phase in northwest Malaya. Bull. Am. Ass. Petrol. Geol. 59, 1015–1019.Google Scholar