GEOLOGIC RECONNAISSANCE IN CARAMOAN PENINSULA, 

 CAMARINES PROVINCE ^ 



By Wallace E. Pratt 

 (From the Division of Mines, Bureau of Science, Manila, P. I.) 



ONE PLATE AND 2 TEXT FIGURES 



CONTENTS 



Introduction. General Geology — Continued. 

 Geography. Geologic history. 



General Geology. Economic Geology. 



Alluvial and littoral deposits. General, 



Isarog tuffs and agglomerates. Gold. 



Pliocene tuffs, flows, and ag- Copper, 



glomerates. Mercury. 



Tertiary sedimentaries. Coal. 



Metamorphic sedimentary rocks. Clay. 



Basal igneous complex. Stone and gravel. 



Correlation. • Artesian water. 



INTRODUCTION 



At the time the field work was performed for a geologic 

 reconnaissance of southeastern Luzon,- it proved to be almost 

 impossible to study the inaccessible region of Caramoan Penin- 

 sula except from a distance. In March, 1914, I had an oppor- 

 tunity to accompany a party from the Bureau of Forestry into 

 this little-known area and to obtain general data as to its 

 geologic constitution, thus extending proportionately the geologic 

 reconnaissance map of Luzon Island. The accompanying topo- 

 graphic map (fig. 1) of Caramoan Peninsula was made by 

 Arthur F. Fischer and Raphael Medina, foresters, Bureau of 

 Forestry, in company with whom I worked, and is based upon 

 Coast and Geodetic Survey charts. 



GEOGRAPHY 



Caramoan Peninsula, jutting toward the northeast from the 

 southeastern peninsular portion of Luzon, forms a distinct phys- 

 iographic province. The region is mountainous and of extreme 

 relief. Roth ^ and von Drasche * quote Hochstetter's opinion 



^ Received for publication June 21, 1915. 



' Adams, G. I., and Pratt, W. E., This Journal, Sec. A (1911) , 6, 449 et seq. 



° Roth, Justus, Ueber die geologische Beschaffenheit der Philippinen 

 (1873), 333-354. 



'Drasche, R. von, Fragmente zu einer Geologie der Insel Luzon (Philip- 

 pinen). Wien (1878), 39. 



303 



