198 



The Philippine Journal of Science 



1915 



Tuffaceous sandstone. — Throughout this region, but partic- 

 ularly near the volcanic area, are beds which can with 

 difficulty be differentiated from tuff on the one hand and 

 true sandstones on the other. This material is found in its most 

 puzzling aspect at Lubuagan, the capital of Kalinga. The truth 

 of the matter is that the constituents of both the tuff and the 

 sandstone came from the disintegration of volcanic rocks. 

 Whether they were derived from material blown out by explosion 

 or by subsequent erosion can only be told by examination of the 

 shape and condition of the component grains. The point is that 

 the constituents in both cases may be much the same. As one 

 goes eastward it becomes easier to make these distinctions. 



Fig. 4. Sketch showine slide near Sagada. 



Sandstone. — A typical exposure of what might be termed the 

 Kalinga sandstone is found on the banks of Chico River near 

 the Nipon resthouse. At this place the sandstone and alternating 

 shale beds are exposed for almost a kilometer on the west bank 

 of the river. The dip of these beds is 65^ and a trifle to the north 

 of west. The sandstone is a coarse, grayish to buff material, 

 which shows plainly its derivation from andesitic rocks. Along 

 the bedding planes ripple and wave marks are very plain and 

 abundant. There also was seen an impression apparently made 

 by a long-stemmed reedlike plant. Unfortunately this specimen 

 is too imperfect for identification. It is possibly the remains 

 of a gigantic sea weed, or a reed which grew in brackish water 

 or in the swamps near the sea. No animal remains were found 

 in this exposure, but at a road camp along the trail between 



