THE GEOLOGY OF LUZON, P.I. 57 
Much that passes as laterite in the East is undoubtedly merely a 
product of weathering of rocks, in place, though it is recognized 
that there is more than one mode of origin. 
ECONOMIC 
COAL 
No workable coal seams have been yet opened upon the Island 
of Luzon, though in Spanish days, some pretense was made to work 
some seams at Bacon in Sorsogon Province. At this place, the 
seams appear to be continuations of those on Batan Island. The 
Spanish engineers had opened up these seams with several hundred 
meters of galleries. 
Coal has been found at several other places on the mainland, in 
the sub-province of Bontoc Ilocos Sur, Rizal, Bulacan and Tayabas, 
but either in too small seams, or in unfavorable localities. 
However, on two islands, so near the Luzon coast as to be 
practically a part of that island, namely, Polillo and Batan, work- 
able coal seams have been prospected and partially developed for 
some time. 
Batan Island—The East Batan mine, which is located on the 
East end of Batan Island, consists of several hundred feet of 
underground workings on a seam of coal about five feet thick. 
The main entry to this mine is about 1,500 feet long, and runs in 
on the coal seam, at an angle of 42° from the direction of dip. The 
dip of this seam varies between 10° and 13°. The coal is a sub- 
bituminous coal with lignite qualities. 
The government has erected at this mine large coal pockets and 
the coal is being used in the island steamers. Some development 
work was carried on on the western end of this Island by the 
United States army in former years, but it has now been abandoned. 
Polillo Island.—On the eastern side of Polillo Island which lies 
in turn on the eastern coast of Luzon, there are four, probably five, 
seams of a very fair grade of coal. Two of these, possibly only one, 
will be found to be advantageously worked. These seams are 
dipping at a moderate angle toward the coast, but near the center 
of the Island where the coal measures abut sharply against the 
igneous rock, the seams are highly inclined, and in some Cases 
vertical. 
