GEOLOGIC EEOONNAISSANCE OF MINDANAO AND SULU. 495 



We halted for the night at 75 meters' elevation at Sinauilan 

 Creek, where soft, bro^vnish-gray sandstone and conglomerate 

 is exposed. 



December 19, 1907 : Left camp at 6 a. m. Not much change 

 either in topography or geology is apparent. Arrived at Digos, 

 a small barrio on the coast of Davao Gulf, about 12 m., after 

 a long walk over ground gently sloping to the beach. Here 

 we spent the rest of the day and the night. 



December 20, 1907 : We sent our cargadores and guard o:i to 

 Davao by trail while we took the launch Bolinao which stopped 

 off this point at noon. We arrived at Davao about 7 p. m. 

 after stopping at two or three plantations on the way and went 

 ashore the morning of the 21st. 



At Digos we obtained our first elear-eut view of Apo. 

 The mountain, stood out clearly and boldly, a shariD 

 cone set to the south and back of an older truncated 

 mass which had evidently blown off its head in some 

 firiniordial paroxysm. On the southeastern side is a 

 huge crevasse, from which puffs of a bluish-white vapor 

 issue. Below 2,100 meters there is a dense Jungle, a 

 mass of green, but above this line the surface is all 

 barren rock and apparently treeless, although when we 

 ascended the mountain we found small bushes of blue- 

 l^erries. 



The present high peak known as Apo did not pour 

 the great mass of lava and rock over this entire region. 

 The explosion crater was about 8 kilometers to the north- 

 east. Fig. 4 shows a profile sketch of this mountain.^-' 



A walk back over the plain behind Davao is interest- 

 ing. About 300 meters behind the town, or about 2 

 kilometers from the beach, unmistakable signs of old 

 beach lines are found, marked by one distinct terrace 

 at least 15 to 33 meters above the flat on which the 

 town is located. All this territory is made up of alluvial 

 wash from the hills. The bowlders are largely andesitic. 



Lieutenant Caffery left the party at Davao to return 

 to Zamboanga. Without his assistance the reconnais- 

 sance, up to the point where Davao was reached, would 

 have been impossible. 



Daron, on the west side of the Gulf of Davao, was 

 the starting point for the ascent of Mount Apo, the 

 party consisting of Mr. Ickis, Mr. Goodman, who had 

 just arrived from Manila, and Messrs. Carrigan and 



"" A good jjicture of Mount Apo will be found in the article 

 on Volcanoes and Seismic Centers, in the Census of the Phil- 

 ippine Islands. (1903), 1, 201. 



