502 GOODMAN. 



feldspar aud ferroraagnesian minerals, a considerable proportion of sec- 

 ondary quartz and microscopic crystals of ajDatite. 



A fractured, but hard and siliceous noncrystalline rock, which under 

 the microscope plainly exhibits a flow structure, is also encountered. 

 This is undoubtedly the surface phase of the igneous flow. Another 

 phase of the basal rock is a chloritie schist, reddish-browTi in megascopic 

 specimens, and containing a large amount of secondary quartz. This 

 rock is probably an alteration product of the original diabase. 



Both coasts of the peninsula are composed of sedimentary strata. A 

 pink limestone intersected by numerous veinlets of ealcite rests on the 

 west flank of the igneous intrusion, while the east coast is mainly 

 conglomerate and brown shale. At Mount Badas these beds attain a 

 thickness of ever 180 meters and dip about 45° toward the southwest. 



East of Mati and between the Bays of Pujada and Mayo is a stretch 

 of agricultural land about 13 kilometers in width. The greater portion 

 of this consists of a table-land elevated about 30 meters above the general 

 level of the present coastal plain. The plateau is terminated to the 

 oast and west by steep slopes; on the south, a narrow spit of land, which 

 at high tide is but very little elevated above the sea, connects this table- 

 land with what originally was undoubtedly an island off the main coast, 

 but is now the southern point of the peninsula which separates Pujada 

 Bay from Mayo Bay. 



The country becomes more rugged and mountainous east of Mayo. 

 The geologic formation is entirely sedimentary. The ridge extending 

 from Mount Mayo to the bay of the same name, terminates in a bluff of 

 conglomerate, dipping at an angle of approximately 30° to the east. At 

 the coast line, the conglomerate presents a section of about 150 to 200 

 meters in thickness, and is composed of small, igneous bowlders. The 

 wave action on this coast is extremely powerful, particularly during the 

 period of the southwest monsoons, and the resulting erosion of the softer 

 beds is plainly marked. 



At a place called Lucatan, about midway between Mayo Bay and the 

 town of Tarragona, the formation changes from conglomerate to lime- 

 stone, the latter apparently overlying the fonner. The limestone is 

 coralline in structure and is plainly an old reef rock that has been elevated 

 to its present height by the general uplift of the coast. The dip and 

 strike of this formation could not be ascertained, but as it is succeeded 

 on the east by another outcrop of conglomerate, dipping about 14° 

 in the direction S. 77° E., it must be inferred that the limestone lies im- 

 conformably on the underlying conglomerate, or else that the uplift was 

 succeeded by a later stage of subsidence. For lack of supporting evidence 

 of this latter theory, I am inclined to believe the existence of an un- 

 conformity the more probable. 



An outcrop of a seam of coal about 85 centimeters thick exist= on the 



