THE GEOLOGY AND MINERAL RESOURCES OF THE 

 AROROY DISTRICT, MASBATE. 



By Heney G. Ferguson. 

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



CONTENTS. 



Introduction. 

 Field work. 

 Bibliography. 

 The Island of Masbate. 

 Climate. 

 •Population. 

 Topography. 

 Geology. 

 Earthquakes. 

 The Aeoroy District. 



Location and topography. 

 Geology. 



The Kaal formation. 



The iiroroy quartz diorite. 



The Panique volcanic series. 



The andesite. 



The pyi'oclastic rocks. 



The sediments. 



The basic rocks. 



The Mountain Maid limestone. 



The Lanang formation. 



The Port Barrera formation. 



Later alluvial deposits. 



Summary of geologic history. 

 Economic Geology. 



History of mining. 

 The veins. 

 The ore. 



Individual properties. 

 Other metals. 

 Mining Conditions. 

 Location. 

 Transportation. 

 Timber. 

 Power. 

 Labor. 



INTHODUCTION. 



Field work. — During the winter of 1907-1908 1 was engaged in geo- 

 logic and topographic field work in the Aroroy mining district on the 

 Island of Masbate. Although the greater part of this time was spent 

 in topogTaphic mapping (See Plate I), a portion was devoted to a 

 preliminary study of the geology, and a short reconnaissance made over 

 a portion of western Masbate. In the spring of 1909 I made a two 

 weeks' visit to the island for the purpose of collecting mining statistics. 

 However, the major portion of the geologic work was done in the autumn 

 of 1909. During the greatest part of the topographic work the writer 

 was assisted by Mr. E. jST. Clark, field assistant of the division of mines. 

 Thanks are due to all the mining men of the region, especially Messrs. 

 Berkenkotter, Herbert, Kimball, and Edelmaier, for their unfailing 

 hospitality and courtesy, and for much valuable assistance. 



Bibliographij. — It was not until after the rediscovery of gold at Aroroy 



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