332 



University of California Publications in Geology [Vol. ll 



DUTCH EAST INDIAN AECHIPELAGO 

 Radiolarian cherts are known from many of the islands of the 

 Dutch East Indian Archipelago, occurring on the islands of Timor, 

 Rote (Rotti), Savu, Ceram, Celebes, Buru and Mangoli. 85 In this 

 region there are also serpentines and gabbros, diabases and diabase 

 tuffs. Some of these are Paleozoic in age, but a large part may be 

 Mesozoic. 



On Rote and Savu, the radiolarian cherts are found in place. In 

 the other islands they are found as detached blocks or as rolled peb- 

 bles in later deposits. 



Most of the cherts are free from calcium carbonate, but some con- 

 tain admixtures of calcareous material. Also there are radiolarian 

 limestones associated with the cherts and in these limestones the 

 radiolaria are largely replaced by calcite. 



The limestones of Rote and Savu contain numerous Halobia and 

 Daonella, and from their close association with the cherts, these rocks 

 also are seen to be Upper Triassic. In Savu the limestones in one 

 locality contain a Belemnite, Asteroconites, which is said to be charac- 

 teristic of the Upper Alpine Triassic. The cherts on the other islands 

 are believed to be Upper Triassic also, but there is a possibility that 

 the cherts from Buru and Mangoli may be Jurassic or Lower Cre- 

 taceous. 



THE PHILIPPINES 

 Radiolarian cherts occur in the Philippine Islands, there being 

 numerous occurrences in Bulacan, Palawan, Mindoro and Mindanao, 

 in association with rocks much like those associated with the cherts 

 in California. 80 



The outcrops of chert are isolated and of limited extent and 

 appear to represent lenslike bodies of chert ; they are revealed by 

 boulders and fissile slabs of chert from five millimeters to several 

 centimeters thick, scattered over the surface of the ground. 



The cherts are red, brown, and gray in color, frequently being 

 laminated. 



85 Hinde, G. J., Radiolaria from Triassic and other Rocks of the Dutch East 

 Indian Archipelago vin, Verbeek, Rapport sur les Moluques, pp. 709-51, Batavia, 

 1908. 



se Fanning, P. R., Geologic Reconnaissance of Northwestern Pangasinan, 

 Philippines Jour. Sci., vol. 7a, p. 268, 1912. 



Smith, W. D., The Asbestos and Manganese Deposits of Ilcos North with 

 Notes on the Geology of the Region, ibid., vol. 2a, p. 145, 1907. 



Ibid., vol. oa, p. 327, 1910. 



