Bulletin of the Geological Society of Malaysia, Volume 10, Dec, 1978, pp. 93 – 95
Department of Geology University of Malaya Kuala Lumpur
T.E. Yancey and Syaroel A. Alif record some significant new observations from the Indarung area, Padang District, West Sumatra in their recent paper (1977). In particular they record Upper Mesozoic fossils from five localities, presumeably all from limestone.
In the same area, unconformably beneath Tertiary volcanic rocks, the authors record chert and shale with limestone and suggest that together these can be classified as a new formation, the Indarung Formation, over 1000 m thick, including two limestone members.
I very briefly examined parts of this area during a palaeomagnetic reconnaissance with Mr. Colin Holcombe of Riotinto Bethlehem Indonesia on 12 August 1975. A few observations which I made, and which add to and in some cases differ from the account under discussion, are recorded here; I suggest they indicate the desirability of more detailed mapping in this interesting and accessible area.