THE STRUCTURAL GEOLOGY OF BRITISH MALAYA 



J. B. SCRIVENOR 



Geologist to the Federated Malay States Government, 

 Batu Gajah, Federated Malay States 



In the Geographical Review for July, 1921/ I published a short 

 paper on the physical geography of the southern part of the Malay 

 Peninsula, which is almost the same as ''British Malaya": it has 

 been suggested that a paper on the structural geology of the same 

 country would be of interest. This paper therefore is an attempt 

 to give a brief outline of the geological structure of British Malaya, 

 an attempt which is now possible, though the detailed geological 

 survey of every state has not been completed. 



The table on page 557 is a statement of the geological sequence in 

 so far as it is known at present, beginning with the youngest rocks : 



Most of these rocks, if not all, have their counterpart in the 

 Dutch East Indies. The granite and associated igneous rocks 

 extend to them where a similar view is now held of the date of intru- 

 sion, i.e., the late Mesozioc. The three small patches of Tertiary 

 rocks are but outliers of a great development of similar rocks in 

 Sumatra. Both the younger volcanic rocks (Group 4) and the 

 Pahang Volcanic Series are represented also in Sumatra, as also are 

 the quartzites and shales and the calcareous group. 



The Malay Peninsula belongs to a region of strongly marked 

 coulisses^ that sweep boldly round through the Malay Archipelago 

 in a north easterly direction, on to the Philippines. They are arcs 

 formed at the close of the Mesozoic Era.^ This wrinkling of the 

 earth's crust permitted the intrusion of large masses of plutonic 



' Geographical Review (New York), Vol. XI (1921), pp. 351-71. 



2 This word "coulisse," used by Suess in his Face of the Earth and now by some 

 Dutch geologists in the Malay Archipelago, is applicable to the Malay Peninsula because 

 there the structural features are distinctly "en echelon" like the wings of a theatrical 

 stage. But for this arrangement, the term "arc" is preferable as being more familiar. 

 "Coulisse" figures in French and English dictionaries, but is not in common use, even 

 among geologists. 



3 See Professor W. H. Hobbs, Earth Evolution and Its Facial Expression, p. 147. 



556 



