476 ADAMS AND PRATT. 



northeastward. On the western margin the beds are upturned. Coal 

 is found in this upturned portion. 



Coal. — The coal at Gatbo mentioned in Burritt's report as being at 

 Sugud, became the property of a Spanish stock company, "La Paz/' 

 in 1874. The Spanish Government donated to this company the services 

 of Jose Centeno, chief of the inspection of mines, and during the next 

 two years, according to Centeno's report, extensive development work 

 was carried out. Little evidence of this development work remains 

 to-day. The gi-ade for an old tramway may still be traced, leading from 

 a small wharf at Gatbo to a eaved-in shaft several kilometers to the 

 southwest, l^ear this shaft are the I'uins of an old camarin in which 

 stands a small masonry engine-base. A true outcrop of the coal seam 

 occurs in the bed of an adjacent creek, and, directly across this creek from 

 the old shaft, the seam has been reopened by a tunnel about 10 meters 

 long, probably the work of recent prospectors. The coal is shown to 

 dip vei-tically and strike north 28° west. Its apparent width is 3 

 meters. The coal in the tunnel contains •'Tiorses" of shale. Other 

 outcrops may be seen near Gatbo. They are all impure, with lenses 

 of shale and clay. 



These coal outcrops indicate thick coal beds. The dip, if constant 

 with depth, is not a serious disadvantage. If Centeno's report be 

 accepted, the property undoubtedly is susceptible of being mined. If 

 Centeno's report be ignored, the coal still merits thorough exploration. 

 It seems probahle that displacement through faulting would be met with 

 in extensive development. It may be pointed out that such a difficulty 

 would be less serious with a vertical bed than with one more nearly 

 horizontal. 



SORSOGON LOWLAND. 



The greater part of this area is covered with unconsolidated materials 

 which have been derived from the adjacent highlands, or with volcanic 

 tuff and pumice Avhich probably were deposited in the sea at a time 

 ■when the isthmus was submerged. 



The underlying formations were seen, poorly exposed on the road from 

 Sorsogon to Gubat where some cuts have been made. They are lime- 

 stones and decomposed igneous rocks which perhaps are andesites. It 

 is probable that the Tertiary formations of the Gatbo upland continue 

 for some distance under the surface deposits of this area. 



There are narrow littoral deposits on the borders of the area which are 

 not shown on the geologic map, and there is considerable alluvium 

 at the mouth of the river which passes Juban. 



BULAN COASTAL PLAIN. 



The formation of this plain consists of tuff and pumice which prob- 

 ably was deposited in the sea. The exposures seen in the low sea cliffs 



