﻿430 cox. 



these analyses may be of service in indicating the quality and the extent of 

 the distribution. 



McCaskey 21 in discussing the occurrence of clay in the Philippine 

 Islands says: 



White clays, or kaolin, have been found in the Provinces of Abra, Camarines, 

 Ilocos Norte, Antique, Benguet, Cagayan, Isabela, Laguna, Marinduque, Masbate, 

 Parapanga, Pangasinan, Albay, Romblon, and Zambales. 



Red clays, from which natives make large amounts of pottery for local use. 

 are found in almost every province in the Islands. 



Fire clay has been found in the coal beds and may afford a profitable industry 

 in the future. 



Red bricks are made in large quantities in Bulacan, C'apiz. Rizal. Ilocos Norte. 

 Isabela, Marinduque, Masbate, and Parapanga. 



Xot much information is available regarding the magnitude of these 

 deposits in Luzon; but the geologists report some of them to be large. 

 Ickis 22 sa3's : 



In the Pajo Arroyo about 3 miles west of Los Banos and li miles from the 

 lake occurs a deposit of white clay which at present is being mined, sacked, and 

 carried on the backs of natives to the Los Banos road ; thence it is carted to Los 

 Banos and shipped to Manila. All of the clay contains brown, iron-stained streaks, 

 but below the first 2 feet the percentage of iron-stained material is very small. 

 For a depth of 2 feet the clay contains some organic matter, besides a consid- 

 erable percentage of iron, and is very plastic. The firm, white clay below varies 

 greatly as regards plasticity. Most of the material exposed in the various holes 

 possesses this valuable quality to a limited extent only, but one pit on the west 

 side of the arroyo furnishes a pure, white clay highly prized by the workmen, 

 which is much more plastic. Sample number 10, taken from the largest pit on 

 the east side of the arroyo, represents the first class while number 7 is a sample 

 of the more plastic clay. 23 



It was impossible for me to determine the extent of this bed of clay, owing 

 partly to the limited time at my disposal and partly to want of exposures or 

 extensive development work, but from surface indications the deposit seems to be 

 large. 



A study of Table III plainly shows that if deposits of sufficient 

 magnititde warrant the establishment of porcelain factories, these kaolins 

 can be recomposed by judiciously selecting and combining the clays with 

 other materials to give the desired results. For example, if 70 per cent 

 of specimen number 2, 20 per cent of feldspar (K,0-Al,0 3 -6SiO,) 

 and 10 per cent of flint (Si0 2 ) were to be mixed together, and the result 

 calculated, which would be obtained after the expulsion of the water and 

 other material lost on ignition, we woidd obtain the following compo- 

 sition : 













Titanic 



Silica. 



Alumina. 



Iron. 



Lime. 



Magnesia. Alkalies. 



oxide. 



58.3 



34.8 



0.87 



0.13 



0.0 4.90 



1.07 



21 Fifth Annual Report of the Mining Bureau, Manila (1904), 35. 



22 Sixth Annval Report of the Mining Bureau, Manila (1905). 58. 



23 The analyses are given under the same numbers in Table I. 



