THE SOLID BITUMENS OF LEYTE 



By B. Nelson 



Chemist, Bureau of Science, Manila 



TWO PLATES AND TWO TEXT FIGURES 



Natural solid bitumens occur in Leyte Province in two forms : 

 pure bitumens and bitumen-impregnated rocks. The outcrops 

 of pure bitumen occur in thin veins, while bitumen-impregnated 

 rocks are found disposed in strata and in faults. Maps drawn 

 by Pratt, who does not distinguish between the two varieties 01 

 bitumens, show the location of bitumen throughout the island. 1 

 One of these maps is reproduced here as text figure 1. 



The pure bitumens of Leyte possess but little interest from the 

 point of view of industrial development. Their applications 

 might be numerous if large quantities of the material existed, 

 but it has been found in very limited amounts. However, the 

 rock presents a certain scientific interest, as it differs from all 

 known mineralogical species of pure bitumen, and the study of 

 its composition is also interesting in view of its relationship to 

 the second variety of bitumens. The latter presents considerable 

 economic importance as it occurs in large quantities and has 

 been found practicable for road building. 



In view of this, I will give only a cursory description of the 

 pure bitumen and will consider the bituminous rocks in some- 

 what greater detail. 



PURE BITUMEN 



The samples of this material which I studied have been taken 

 from outcrops that were disposed horizontally at the foot of a 

 hill, within a layer of shale, covered by a layer of clay, about 

 2 to 3 kilometers southeast of Campocpoc, west of Bagubao River, 

 in the northwestern part of the island. They had the appearance 

 of dark brown stones of considerable hardness and brittleness 

 and conchoidal fracture, yet they were not sufficiently brittle to 

 be pulverizable. Their surface, lustrous when fresh, presented 

 greasy spots when aged, betraying the lack of perfect homoge- 

 neity. Rubbed against unglazed porcelain the rock leaves a 

 brownish yellow streak. 



1 Philip. Journ. Sci. § A 10 (1915) 241. 



