﻿BAGUIO MINERAL DISTRICT. 219 



Typical mountain topography prevails on both these eminences (Santo 

 Tomas being included, although abnormal). There is but little good 

 water, almost none in fact, at these elevations, standing as they do clear 

 of all the surrounding country; consequently all erosion is a direct 

 result of the very considerable rainfall of 100 to 120 inches per annum. 

 Denudation has been rapid, especially on Santo Tomas and deep scars 

 have been cut into its flanks by the erosion of the streams carrying the 

 run-off. All the streams are naturally far above base level, and deep, 

 Y-shaped gorges represent the type of stream beds. While frost is rare 

 here, the difference in temperature is sufficiently great, no doubt, some- 

 what to aid in the disintegration of the rocks. Steep slopes prevail, 

 and talus is carried away by the excessive erosion, so that sharpness of 

 outline continues to exist. 



THE ELEVATED PLATEAU. 



The Baguio Plateau is the most striking of the four physiographic 

 types of the region. It is a peneplain of limited extent, with an average 

 elevation of about 5,000 feet and with a drainage and topography so 

 characteristic of a lowland region, that, viewed from a central point 

 where the valleys of the Bued and Agno River drainage are not visible, 

 it is hard to realize the situation of the area. 



The drainage is not deeply marked and there is plain evidence of much 

 shifting of divides and valleys. Only small streams prevail over the 

 region and except for transitional border areas where gradients, are in- 

 creased very rapidly before the streams drop off into the deeper valleys, the 

 erosion has not been great in stream beds. Baguio proper drains to the 

 north into the Irisan and Trinidad Bivers. The Pakdal area divides its 

 drainage between the north, uniting with that from Baguio, and the south- 

 east, draining into the deeper valley of the Agno tributaries. There are 

 no streams of any size in this portion of the district and the large rainfall 

 seems to be partly added to the ground water and partly run off in 

 numerous small channels, rather than through any well defined system. 



South of Baguio and Pakdal the drainage is to the east and west of 

 the Baguio-Kias Bidge, into both the Bued and Agno waterways. The 

 topography is of a mature type over the entire region. Low, rounded 

 hills with gentle slopes, graded valleys with low gradients and in part 

 winding streams which show some small amount of rejuvenation in the 

 more deeply cut valleys exist, but they have not altered the serpentine 

 course they followed originally. The stream draining Baguio affords one 

 instance of this character. It is a barely noticeable brook from the divide 

 where it originates up to a ponding which occurs south of Bagnio; 

 the softer rock materials here have yielded to erosion and the stream, 

 although formerly large and flowing directly from the depression through 



