6 FERGUSON. 



The Guinobatan River presents several peculiarities in its course, 

 inexplicable except by the supposition of superimposed drainage. Ris- 

 ing to the east of Mount Vil-lon it flows alternately west-northwest and 

 west. North of Mount Vil-lon it flows to the west with long, graded 

 stretches and small rapids. At the junction with the Kaal there is a 

 small fall and the course changes to nearly north with one sharp ox-bow, 

 until it reaches the junction Avith Balagting Creek, where it turns 

 sharply to the west and enters a deep canyon between Mounts Bagadilla 

 and Kalakbao. This canyon, 2 kilometers long, cuts diagonally across 

 almost the whole of the vein series. After a sharp turn to the south- 

 west at the Gold Bug mine, the river flows north for 3 kilometers to 

 its junction with Bangong Creek, where it turns to the west again and 

 enters the mangrove swamps that surround the bay. On this northerly 

 stretch the river again cuts diagonally across the trend of the veins, 

 but here it is noteworthy that, while outcrops and bowlders show the 

 presence of veins extending down to the river on the eastern bank, the 

 hills to the west are entirely barren. This northern stretch is parallel 

 to the bay and only a kilometer from it. Evidently there is a northerly 

 element in the lineaments of this district, which, while less distinct 

 than the northwestern and southwestern trends, shows in Port Barrera, 

 the line of low hills on its eastern shore and the lower part of the 

 Guinobatan. 



The Lanang River also has a very peculiar course. Rising in the 

 mountainous upland in the central part of the island, it enters the 

 Aroroy district with a northwesterly course, then suddenly turns to the 

 southwest and for 2 kilometers flows through a deep, narrow gorge, when 

 it turns again at right angles and flows irregularly to the northwest for 

 the same distance until it once more makes a sudden turn and takes a 

 northeast course through a smaller, but similar gorge. From here on 

 it flows to the north through a small flood plain until it enters the great 

 mangrove swamp of the upper part of Port Barrera. Northwestward 

 from the angle made by the river, on entering the upper gorge, a 

 broad and rather flat valley is found between two ranges of hills. This 

 valley would seem to be the natural course of the Lanang, and the sharp 

 angle of the river and the small stream entering at this point suggest 

 capture. However, there seems to be no reason why a stream having 

 such a direct and regular course should be captured by one so unfavorably 

 situated as is the present Lanang River. A possible explanation is that 

 Assuring in a northeasterly direction has produced lines of weakness, 

 allowing a stream leading in this direction an advantage over the more 

 regular stream flowing northwest. The course of the river in the upper 

 gorge, prolonged to the northeast, would be continued in the valley to 

 the southwest of the hill forming the divide between the headwaters on 



