276 The Phili'pvine Journal of Science 1915 



tors are effective in controlling the accumulation. To determine 

 these points, a detailed geologic study should be made both in 

 the vicinities of anticlinal structures and in the vicinities of 

 intrusions in Leyte. 



It appears from the preliminary study that anticlines across 

 the crest of which the rocks above the Vigo shale remain in 

 place — that is, have not been eroded — are more promising than 

 the anticlines upon the limbs of which the Vigo shale is ex- 

 posed. The anticline at outcrop D, for instance, has afforded 

 less chance for the escape of accumulated petroleum because of 

 the presence of a cover of Canguinsa clay-tuff across its crest 

 than the anticline at I and J, where the upturned edges of the 

 Vigo are exposed at the surface. The anticline between I and 

 J must be considered with still less promise, if the igneous ex- 

 posure at I proves to be a part of the base upon which the Vigo 

 lies. Nevertheless the large exposure of Vigo shale lying to 

 the east and south of Villaba should be gone over in detail, 

 particular search being made for seepages, intrusions, porous 

 beds, and faults. 



The region between outcrop N and the barrio of Baliti, where 

 both intrusions and anticlinal structure are indicated, should 

 be studied. The regions inland from the several coastal in- 

 dentations between Villaba and San Isidro should be prospected. 

 Seepages of petroleum and outcrops of solid bitumen other than 

 those already discovered probably exist, and fixing the position 

 of such occurrences will facilitate geologic interpretation. 



If petroleum has accumulated in anticlines independently of 

 intrusions, the northern part of the peninsula of northwestern 

 Leyte, where folds undoubtedly exist in which the petroleum- 

 bearing rocks are protected by a splendid cover of Canguinsa 

 and Malumbang strata, should include promising territory. 

 This area, therefore, should receive careful attention. 



If the petroleum accumulations prove to be related invariably 

 to intrusive rocks, the territory surrounding the intrusions will 

 be most valuable. The known intrusions should be examined 

 in the light of this suggestion, and search should be made for 

 other intrusions. 



In prospecting for other deposits of solid bitumens, the area 

 south of Campocpoc is most promising, including territory as 

 yet unexplored between Villaba and Tabubunga. No solid bitu- 

 mens have been found in the Vigo shale; accordingly search 

 for these materials should be directed especially to the upper 

 rocks, although with only the data in hand at present it would 

 be unwise to disregard the Vigo shale entirely. The solid bitu- 



