298 The Philippine Journal of Science 1915 



probably the same one which had been reached in the upper bed. 

 From the face of the drift on the lower bed an opening was 

 now driven up the dip, which gradually flattened, until the bed 

 became horizontal at a distance of 20 meters and then gradually 

 reversed its dip, thus defining an anticline. Along the crest of 

 this anticline another drift was started parallel to the original 

 strike-drifts. This drift progressed a distance of about 100 

 meters in regular coal and encountered no fault, although it 

 advanced far beyond the line of the fault which had displaced 

 the same bed on the limb of the fold. Moreover cross entries 

 were driven down the dip to the right and left, and the persistence 

 of the coal was proved to a point directly in the line of advance 

 of the faulted drift on the limb of the fold. 



At this stage of the work exploration was suspended and has 

 never been resumed. All the advancing faces were in coal 

 varying in thickness from about 2 meters on the crest of the 

 anticline to 1 meter at a distance of 30 meters down the dip 

 on either side. The coal is of superior quality, although some- 

 what crushed by the folding pressures. It appears that a fault 

 had been avoided in this case with no great difficulty, and the 

 exploration, although incomplete, is encouraging. However, the 

 quantity of coal actually proved by this work cannot be placed 

 at more than 10,000 metric tons. 



The mine of the East Batan Coal Mining Company, situated 

 on the eastern end of Batan Island, constitutes the most exten- 

 sive coal exploration performed by Americans in the Philippines. 

 This mine developed a 1.5-meter bed of coal over an area 1,100 

 meters long and 400 meters wide. The main entry was 500 

 meters in length, and one of the butt entries was 800 meters 

 in length. All faces were in coal, and the bed was absolutely 

 regular. A 7-centimeter parting, 45 centimeters from the roof, 

 was maintained everywhere without variation. The only change 

 in the character of the coal was noted in the workings farthest 

 advanced to the west. At this point balls or lenses of hardened 

 mud, containing pyrite, made their appearance in the coal. The 

 company suspended operations for financial reasons and not be- 

 cause of any lack of coal in the mine. The East Batan coal 

 is objectionable as a steaming fuel, because of its low calorific 

 value and its tendency to slack, or disintegrate, in storage. 



In summary, the exploration of Philippine coal beds may be 

 said to show that the continuity of the coal is frequently broken 

 by faulting; that by careful work the coal can usually be re- 

 located beyond the faults without much difl[iculty or expense; 



