328 The Philippine Journal of Science 1913 



beek 12 assigns to the middle stage of the upper Tertiary for Java, 

 and describes as follows: 



Middle and upper Miocene 

 highest beds in part Plio- 

 cene. 



IX. Middle stage of the upper Tertiary. 

 Formations called the marl stage. 

 Abundant marl and marly sandstones. 

 Less abundant sandstone and shale with 

 some calcareous beds. 



* * * IX The second stage or the middle Neo-Tertiary stage m 2 , 

 probably contains at a slightly lesser depth than the lower division, some 

 beds of Middle and Neo-Miocene and even Pliocene age, which cannot 

 always be distinguished in the field and are called by us the "marl stage" 

 on account of the principal rock. One finds here, besides some calcareous 

 sandstones with numerous marine shells, beds of conglomerates and breccias 

 (much less than in the stage M), then some shales, noncalcareous sand- 

 stones and calcareous beds, the last named having occasionally orbitoides 

 with spatula shaped chambers (lepidocyclines) * * *. 



The Cudiapi sandstone, the principal rock in the Malumbang 

 series, might be called a marly sandstone, and the limestones 

 are likewise often sandy or clayey. Shale is not present, but 

 some exposures of the Cudiapi sandstone are argillaceous. 



No indications of petroleum have been observed in the Malum- 

 bang series. It is above the horizon at which oil seeps occur, 

 and bears on the possible petroleum industry only in the fact 

 that it must be drilled through before the petroliferous zones 

 can be explored in parts of the promising territory. 



Canguinsa -sandstone. — The Canguinsa sandstone is a close- 

 grained, gray or blue rock to which the term sandstone applies 

 in a general way. It is distinguished from the Cudiapi sandstone 

 by its massive or less perfectly bedded appearance and by the 

 considerable proportion of clay which characterizes it. The 

 upper portion is usually a soft, clayey sandstone, imperfectly 

 bedded and occasionally close jointed. This sandstone is calca- 

 reous, and several exposures on the upper part of the Canguinsa 

 River are concretionary. The concretions are aligned so as to 

 lend a bedded appearance to the exposure. The concretionary 

 sandstone was not observed to be of general distribution. 



Toward the base of the formation either a typical sandstone 

 or an indurated massive or jointed clay is encountered. Both 

 sandstone and clay occur in heavy banks from 3 to 6 meters thick, 

 and both are slightly calcareous. The sandstone facies in the 

 basal portion is deep blue on fresh exposure, but weathered sur- 

 faces are gray or brown. Ordinarily, it is of medium-grain 

 size, and shows little evidence of bedding. The clay is also blue 



" Verbeek and Fennema, Description Geologique de Java et Madoura. 

 Amsterdam (1896), 1, 38, 41. 



