Dicker son: Baguio Plateau 417 



coralline limestone cliffs are again encountered. 

 These may be traced south almost to Balugan and toward the north to 

 Tetanan. * * * These coral reefs likewise show stratification with 

 clearly discernible thick beds, usually with a southerly inclination of 

 15°-20°; between the strata I found a thin layer of greenish tuff. 



He also mentions coralline limestone and tuff as an extensive 

 mantling formation occurring in the vicinity of Lidlidda. Von 

 Drasche discusses the age of this limestone as follows : 



coralline limestones belong to the most 

 Luzon. They always form the upper- 

 of all formations, and with the exception of Benguet, 

 > they are covered with a thin layer of red earth, I failed to find these 

 i other rocks.* * * * Even though it was impossible 

 to give a reliable specific report on account of the poor state of preser- 

 vation of the fossils, it nevertheless was possible for us [von Drasche and 

 von Marenzeller] to declare with certainty that with the exception of 

 one single piece which we could not identify, all of the rest belonged to 

 genera which occur today in great abundance in the Indian Ocean, and 

 even the individual corals can be referred without any question to 

 living types. The corals examined do not show the least relationship to 

 the Tertiary corals from Java described by Reuss. 



Regarded from this point of view, the raised coral reefs of Luzon must 

 be considered as very recent in origin. The genera identified by us are 

 the following: Galaxaea, sp., Favia, sp., Maendrina, sp., Porites 2 sp. (?), 

 Astraeopora, sp. 



Von Drasche advances the view that Trinidad Valley rep- 

 resents a coral atoll. This hypothesis will be discussed later. 

 The sequence of rocks established by von Drasche was — 



(1) The coral reefs and breccias of coralline limestone with recent 

 volcanic rocks; (2) the tuffs and tuff sandstones associated at places 

 with coralline limestone beds and marls with plant remains; (3) recent 

 eruptive rocks (quartz trachyte, sanidine hornblende-trachyte, hornblende- 

 andesite, and dolerite) ; (4) the Agno beds, a mighty system of coarse 

 sandstones and conglomerates which have been derived from the under- 

 lying diabase and aphanitic rocks; and (5) diorite, protogine gneiss, and 

 chlorite schist. 



A part of von Drasche's second group, as will be shown 

 later, is the Vigo group unconformably beneath the coralline 

 limestone and contains a coral fauna like the one described by 

 Reuss from the Tertiary of Java. However, let this not be 

 regarded as a carping criticism of the work of this hardy 

 geological pioneer who first made known this interesting upland, 

 and who amid privations of numerous kinds could still see 



