318 



The Philippine Journal of Science 



1913 



the relations in the opposite (western) limb of the anticline 

 observed in the western slope of South Cudiapi Mountain and 

 the western wall of Canguinsa River valley along Amuntay 

 Creek. Table VIII is a section in the eastern limb at Bacau. 



Table VI. — Geologic section from the summit of Balinsog Hill downward 

 to the bed of Canguinsa River. 



Formation. 



Description. 



Approx- 

 imate 

 thickness. 







Meters. 





Upper limestone. Coralline, massive, yellow to 



20 





white limestone; not present except in rem- 





. 



nants on Balinsog Hill, but found on neigh- 





Malumbang series 



boring hills. 







Cudiapi sandstone. Bedded, brown to yellow, cal- 



100 





careous sandstone; alternate beds of different 







thicknesses; dip 15° eastward. 







(Lower limestone? Concealed or lacking ... 





i 



Gray calcareous sandstone; bedded, dip slight 



100 



Canguinsa sandstone .. 



to eastward. 

 Gray medium-grained sandstone with abundant 

 sandstone concretions. 



10 







20 



Unconformity? - 







Vigo Bhale ... 



Bacau stage. Blue to black thin-bedded shale; 







occasional outcrops only. 





Table VII. — Geologic section down the east slope of South Cudiapi Mountain 

 along Amuntay Creek to upper Canguinsa River. 



Formation. 



Description. 



Approx- 

 imate 

 thickness. 



1 

 Malumbang series.. 



Canguinsa sandstone 



Upper limestone? Not present; removed by ero- 



Bion? 

 Cudiapi sandstone. Yellow to brown calcareous 



sandstone, bedded; medium-grain size; summit 



of South Cudiapi Mountain. 

 Lower limestone. Yellow to white coralline lime- 

 stone exposed at base of peak of South Cudiapi 



Mountain. 

 Imperfectly bedded, gray to yellow calcareous 



sandstone; dip to westward. 

 Gray to light blue sandy clay; compact and jointed; 



not bedded; fossiliferous. 



Meters. 



80 



20 



60 

 100 





Vigo shale.. J 



Bacau stage. Occasional outcrops only, along 

 Canguinsa River; blue to black, thin-bedded 

 shale; dips steep to east and west. 







