viii, a, 5 Pratt and Smith: Petroleum Resources 307 



bark, and in times of want the wood of the tree is ground into 

 buri flour which feeds his family. 



It may be anticipated that labor will be scarce should this field 

 become active and that the efficiency of the local supply will be 

 low. 



GEOLOGY 



GENERAL STATEMENT 



Bondoc Peninsula is made up almost entirely of sedimentary 

 rocks, and, if the regions of more recent sedimentary material, 

 such as the alluvium and raised shore deposits of the central 

 plain of Luzon and the volcanic tuff of southwestern Luzon, be 

 excepted, is one of the largest areas in the Philippines where the 

 rocks are essentially sedimentary and not seriously affected 

 by intrusion or vulcanism. 



The series is principally shale and sandstone, with subordinate 

 thicknesses of limestone in the higher portion. The youngest 

 beds, disregarding the recent unconformable deposits, are Plio- 

 cene limestones, while the oldest rocks encountered are lower 

 Miocene or Oligocene shales. The measured sections show an 

 aggregate thickness of from 1,700 to 1,800 meters, and the base 

 of the shale series is not exposed. Possible repetition of beds 

 through minor faulting may make the apparent thickness greater 

 than the actual. The strata have been forced into folds along 

 lines trending approximately parallel to the axis of the penin- 

 sula ; namely, north-northwest and south-southeast. The folding 

 has resulted in a principal anticline along the central portion of 

 the peninsula, separated by wide shallow synclines from subor- 

 dinate, more or less parallel, anticlines near the coasts on each 

 side. This simple structure is complicated by the presence of 

 minor folds approximately at right angles to the general trend. 

 The limestone at the top of the series has been folded in general 

 conformity with the lowest shale, so that the major lines of 

 structure are common to the entire stratigraphic column. The 

 anticlines of the folds are sharp, but the occurrence of extensive 

 faulting is not established. 



PHYSIOGRAPHY 



Excluding San Narciso Peninsula, the lower part of Bondoc 

 Peninsula may be considered as a single geographic and oro- 

 graphic province. The outline is regular, with the lateral coast 

 lines parallel, and the width maintained fairly constant to the 

 extreme end. The coasts swing to the west as the southern end 

 of the peninsula is approached, giving the southern portion of 

 the field an almost north and south axis, while farther north 



