X, A, 3 Smith: Reconnaissance of Mountain Province 181 



hand, are cemented together by an earthy binding material. These pieces 

 protrude from the matrix in groups showing no regularity whatsoever. 

 The steep left banks of the Abra very soon disclose a complex of rocks 

 which clearly show stratification and which have a steep inclination toward 

 the north; they are the well-known plagioclase-hornblende-chlorite rocks, 

 which, alternating with white feldspathic strata full of pyrite, make up 

 the Agno beds. 



We finally left the bed of the Abra and went eastward over steep moun- 

 tains with numerous chasms and cliffs toward Pilipit, and from there to 

 Cayan. The entire region is composed of friable, yellow tuffs, that are 

 mostly stratified horizontally. Numerous creeks flow across these tuffs, 

 engorging themselves in the soft rock; the wearisome trail runs up and 

 down directly across their courses. 



Before reaching Pilipit, one has a splendid view of Abra Valley, which 

 spreads into a wide hilly plain a short distance beyond the point where 

 we had left it. Recently successful experiments have been conducted in 

 planting the coffee shrub on this plain. 



Cayan has an elevation of about 4,000 feet upon a small plateau. South 

 of the place is the mountain Data. At the foot of Mount Data there are 

 said to be numerous hot springs; copper ores are likewise found there; 

 perhaps this might indicate a great extension of the quartz lens of Man- 

 cayan toward the east. 



Mount Data plays a very important part in the orography of Luzon; 

 it is, so to say, the watershed of the three great rivers, the Agno, Abra, 

 and Bontoc. 



The sources of the first two rivers have already been described; both 

 flow into the ocean on the west coast. Bontoc River, which has its origin 

 in the eastern part of the Data mountain range, very likely flows into 

 Bangong River; therefore it pertains to the river system of the Rio Grande 

 de Cagayan. 



In the vicinity of Cagayan the true Central Cordillera is merely a much 

 dissected plateau; at a point much nearer the coast it continues its north- 

 northeasterly direction; consequently Cagayan really is situated on the 

 watershed between the west coast and the Rio Grande de Cagayan. Coello's 

 map does not take cognizance of this noteworthy fact. On Plate I this 

 Cordillera is correctly drawn. 



Sabangan, which lies a six-hour walk to the east of Cayan, is one of the 

 most remote toward the east of the rancherias paying Spanish tribute. I 

 made a trip to this place in order to enter from there into Bontoc district 

 that lies to the north. A short distance behind Cayan mighty breccias of 

 doleritic rocks are encountered, then breccias of hornblende-sanidine- 

 trachyte, and farther eastward there appears a breccialike rock bedded in 

 thick layers. The last-named consists of large and small, irregular frag- 

 ments of limestone and of a badly weathered trachytic rock; there are 

 also disseminated fragments of feldspar and quartzite. This conglomerate 

 alternates with strata of coralline limestone, very similar in every respect 

 to that found in Benguet Province. The strata show an inclination to the 

 southeast of 8°-12°. Farther toward the east there again appear soft, 

 yellowish tuffs, which continue as far as the cuartel at Sabangan. Sabangan 

 lies on an eminence, in the angle formed by Sabangan and Bontoc Rivers. 



The large rancheria, viewed from the cuartel, lies deep down on the left 



