RECONNAISSANCE OF MINDANAO AND SULU : III. 39 J 



can be found and conditions of demand and transportation were favorable, 

 a quarry might be opened here for the production of roofing slates. 



The west slopes of the ridge consist largely of calc-schists, while on 

 the east flank chlorite schists predominate. In places the latter are 

 altered to talc-schists. Large masses of red jasper are also to be found, 

 particularly in Sagay Creek. None of the numerous pans of river gravel 

 which I washed during the traverse across the peninsula showed any 

 colors. 



I left the town of Jabonga in a small boat and, because of exigencies 

 of the weather, had to put ashore two or three times, and was thereby 

 enabled to determine the geologic formation of the west coast of Lake 

 Mainit to be very similar to that of the ridge between the lake and the 

 sea, that is, calcareous shale and chloritic schist. 



The town of Mainit is situated on the north shore of Lake Mainit 

 about 3.8 kilometers southwest of the mountain of the same name. 

 I left the town in a small hanca, going eastward along the shore 

 of the lake as far as the mouth of the Magpayang Eiver. About 3.5 

 kilometers northeast of here is a flat terrain enclosed between two 

 creeks called Duyangan which are branches of the Tinagan Eiver. 

 About a generation ago this place had quite a reputation as a placer 

 district, and several shallow pits about one-half to one meter deep are 

 yet to be seen in the gravel, from which a Frenchman named Maximi- 

 Jiano and others are supposed to have taken a considerable quantity of 

 gold. A pan of this gravel taken from the surface showed about a half 

 dozen plainly visible colors and a small tail of flour gold. Whatever 

 wealth this gravel might once have possessed, to-day it is not rich enough 

 to attract even the native women with their hateas. K number of pans 

 taken between the surface and hard pan, which lies about 1 meter below 

 surface, yielded only at the rate of from 9 to 31 centavos per cubic meter. 

 There were no signs of the hard pan having been penetrated, and what 

 might be found below it remains problematical. Both the surface gravel 

 and the underlying hard pan contain a considerable amount of chalcedonic 

 quartz and concretions of brown clay-ironstone, as well as some black 

 sand, pyrite, and gold. 



A wide, open stretch of flat cultivated land is passed in going north 

 from Tinagan. The geologic formation here was difficult to determine 

 for lack of outcrops, but near the town of Timamana about 3.3 kilometers 

 northeast of Mount Mainit are three or four hills, 20 to 30 meters high, 

 and composed of crystalline limestone. These hills are plainly the un- 

 covered portions of the underlying formation, standing out above the 

 tuffaceous material derived probably from the ejecta of Mount Mainit 

 in its active state and which at present cover the rest of the underlying 

 formation. 



The trail northward from Timamana passes almost on the contact 



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