GEOLOGIC RECONNAISSANCE OF SOUTHEASTERN LUZON. 



By George I. Adams and Wallace E. Pratt. 

 (From I lie Division of Mines. Bureau of l^cience, Manila, P. I.) 



CONTENTS. 



INTBODUCTIOiN . 

 PHTSIOGEAI'HY. 



Geology. 



Southeastern Cordilleni. 

 Caraiuuan Peninsula. 

 Batan Island C'liain. 

 Ragay Coast Hills. 

 Bicol Valley. 



Geoloo V ( continued ) . 



Eastern Cordillera. 



Viuas lowland. 



Gatbo upland. 



Sorsogon lowland. 



Bulan coastal plain. 

 Mineral resources. 



INTRODUCTION'. 



This rc'0OJiiiai.sijance continues geographically the study of the geology 

 of the Island of Luzon from the southwestern portion, concerning which 

 a rejjort has been published.^ to the southeastern extremity. These two 

 areas are indicated on the index map as shown in text figure 1. The 

 physiographic and geologic divisions are distinct, with the exception of 

 portions of the Eastern Cordillera which occupy a part of each area arbi- 

 trarily limited for convenience in mapping. Both divisions of the Island 

 contain volcanic features which are of especial interest. In southwestern 

 Luzon there are some isolated volcanic peaks, crater lakes, cinder cones, 

 and the Volcano Taal. Southeastern Luzon contains a notable range of 

 volcanic peaks, iiic-lnding the exceptionally symmetrical and perfect cone 

 of Mayon. 



These two parts of Luzon with their minor features form an epitome 

 of the geology of the Islands. Von Drasche made a partial reconnaissance 

 of these areas. It was hoped that the present report would complete a 

 systematic reconnaissance, but the time for field work, which was limited 

 to the months of April. May, and June, precluded such a result, although 

 it permitted the study of the greater part of the area. Previously, a recon- 

 naissance of the Tavabas oil field had been made and the results which 



This Journal. Sec. A (1910), 5, 57. 



449 



