﻿COMPOSTELA-DANAO COAL FIELD. 397 



Lepidocyclina and Gycloclypeus. This series extends northward through the 

 Philippines to central Japan. 



Eocene; marine beds of small extent with Nummulites, Alveolina and Ortho- 

 phragmina. They contain coal. 



Cretaceous limestone with Obitolina from Banjoemaas. This rock is not known 

 to exist at other points in Java. 



By comparison with the table on page 390 it will be seen that my 

 column is fairly well in accord with Verbeek's divisions in Java, and 

 with Martin's Pliocene-Miocene or Java series. 



Recent formations. — The latest deposits to be laid down in this region 

 are those which are still forming in the river bottoms, on the coastal plains 

 where the streams issue from the mountains, and along the coast, but 

 in our limited field we need only refer to two of these, the river-bottom 

 deposits and the talus slopes, for these are in part alluvial, although grav- 

 ity is probably much the most potent agent in producing the latter, 

 whereas water is the cause of the former. 



All the waters in this region in addition to the mechanical detritus of 

 the streams, carry a large quantity of lime in solution. This is generally 

 deposited on the shales of the coal measures. I have- picked up fresh- 

 water snail shells which had a coating of half an inch in thickness of 

 calcium carbonate. 



STRUCTURE. 



The importance of geologic structure is nowhere exemplified as it 

 is in a coal field. Not only the condition of the coal is generally greatly 

 changed by an increase in the inclination of the strata, but the cost 

 of mining is enhanced almost in geometric ratio under certain condi- 

 tions; an instance of such conditions being those under which the 

 miner is forced to work down the dip, hauling the coal up an incline by 

 steam or electricity, and where it is necessary to pump. In , discussing 

 the structure of this district I shall merely make mention of the struc- 

 ture of the coal measures. The general strike of the formations on the 

 east coast of- Cebu is north and south, but in the Compostela-Danao 

 region the Cordillera swings somewhat to the east and likewise the 

 strike of the coal measures changes to about 1ST. 25° E. The dip, which 

 on this side is generally easterly, changes to southeast. It is not uni- 

 form, uninterrupted and always to the east, but in some places the forma- 

 tion is plicated to an extreme degree, with westerly dips. An instance 

 of the close folding is shown in the cut of the tramroad just below the 

 Camarin at Camansi, and again in Suqui Creek, where the igneous rock 

 is approached; besides this there seems to be abundant indication of a 

 minor north and south cross folding, but this is not a bad feature, as 

 it is not noticeable except over great distances. 



I am not able to assert that much indication of faulting appears on 

 the surface, although I suspect it to have been considerable, but of a 

 minor character, in this district and until more underground data are 



