PR ee ee RBG era eee 
PRELIMINARY GEOLOGICAL RECONNAISSANCE OF THE 
LOBOO MOUNTAINS, BATANGAS PROVINCE. 
By W. D. Situ. 
(From the Division of Mines, Bureau of Science, Manila, P. I.) 
CONTENTS. 
INTRODUCTION. 
Field work. Previous investigations, literature, ete. 
DISCUSSION. 
Physiography. Topography and drainage, climate, vegetation, ete. 
General and local geology. 
Basement complex. 
Sedimentaries (marine). 
Tuff deposits. 
Economie geology. 
Ore deposits; assays. 
Prospecting and development work. 
Transportation and harborage. 
Paleontology. 
Stratigraphy. 
Description of species. 
CONCLUSIONS. 
PLATES. 
INTRODUCTION. 
The writer, during portions of the months of August and September, 
1905, was detailed from the Mining Bureau to make a preliminary geo- 
logical inspection of the Loboo region where some prospecting was being 
carried on. Unfortunately, this reconnaissance was of necessity limited, 
but it is thought even the incomplete data already at hand should be made 
available. Furthermore, as very little literature and that not easily 
accessible to the public, can be found treating of this portion of Batan- 
gas Province, these notes may possess some utility at home, as well as 
scientific interest abroad. 
The able Spanish engineer, Centeno,t has written of the Taal tuff 
deposits, which extend partly into the district discussed in this paper, 
but he extended his observations to a region no farther east than the 
pueblo of Batangas. Von Drasche* published some notes on the region 
of southeastern Luzon, but he likewise did not touch upon the Loboo 
country. 
The field work done by the writer consisted primarily of an inspection 
1 J. Centeno: Estudio geologico del Volean Taal, Madrid, Tello (1885). 
*R. v. Drasche: Fragmente zu einer Geologie der Insel Luzon, ete., Vienna, 
rerold’s Sohn (1878). 
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