GEOLOGY AND FIELD RELATIONS OF PORTLAND CEMENT RAW 

 MATERIALS AT NAGA, CEBU 



By Wallace E. Pratt 

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



One plate and 3 text figures 



INTRODUCTION 



In 1911 the Bureau of Science undertook to investigate the 

 possibihties of manufacturing Portland cement in the Phihppine 

 Islands somewhat more comprehensively than had been attempted 

 previously, and began the work with a study of the geology 

 and field relations of the raw materials. The possible manufac- 

 turing sites which had been discussed by previous investigators ^ 

 and all other districts where the requisite calcareous and siliceous 

 materials had been encountered under conditions at all favorable 

 as to the factors of transportation, fuel, and markets were 

 included in this study. Samples were collected for subsequent' 

 chemical examination and experimental burning tests. 



A general statement of the results of the geologic investiga- 

 tion was published in 1912,^ and the vicinity of Naga, Cebu, 

 was noted as one of the possible sites which were considered 

 most favorable. The central position of Naga in the Archipelago 

 throughout which the product could be marketed and the 

 proximity of the raw materials to railroad and harbor facilities 

 and to fuel in an adjacent coal field were found to be the principal 

 advantages of this site, apart from the unusual suitability of 

 the raw materials themselves. The raw materials from Naga 

 have been burned to a superior Portland cement both by testing 

 laboratories in the United States and in the Bureau of Science,* 

 and the geology and field relations at Naga are taken up in this 

 paper to supplement these data, 



SITUATION 



The proposed manufacturing site is on the southeastern coast 

 of Cebu, at the mouth of Pandan River, a small stream which 

 empties into the sea near Naga. The Philippine Railway crosses 



'Cox, Alvin J., This Journal, Sec. A (1909), 4, 211; ibid. (1908), 3, 391. 

 'Pratt, Wallace E., Min. Resources P. I. for 1911 (1912), 82. 

 'Reibling, W. C, and Reyes, F. D., Thin Journal, Sec. A (1914), 9, 127. 



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