476 .SMITH. 



and quartz porpliyiies. ilelaphyre lie found again at Pujada Bay near Cape 

 San Agustin. Quartz breccias also occur on the divide between Pujada and tlie 

 Gulf of Davao. Serpentine accompanies the melaphyre to the south of Bislig/' 



"Mr. Minard visited the gold-bearing region of Misamis, the northwestern prov- 

 ince (A Mindanao. The sandstones and conglomerates of the Iponan Valley, dipping 

 12°, are said to be broken through at many points by dlorite and serpentine. The 

 pebbles of the conglomerates include diorites, augite-porphyry, serpentine, jasper, 

 and marble." Some years later Jlr. Abella made a reconnaissance of this region, 

 examining the gold deposits along the courses of several rivers, all of which empty 

 into Macajalar Bay. They are the Iponan, the Cagayan, the Bigaan, and the 

 Cutman. In this region he found two consideiable areas of old slates. One of these 

 touches the Iponan River 10 or 12 miles from the sea. The other is intersected by 

 the Cutman and approaches the sea within 2 miles, near the town of Agusan, which 

 lies at tlie mouth of the Cutman River. Alluvial deposits fringe the shore of 

 the bay and follow the streams. Otherwise the country, as depicted by Mr. Abella. 

 is covered with strata provisionally referred to the Miocene. The slates are 

 described as metamorphic and in part steatitic. The pebbles of the Tertiary 

 conglomerates consist of such slates, serpentinoid rocks, and many varieties of 

 'trachytic rocks.' I think that at the date of his memoir, 1879, Mr. Abella used 

 this term for neo-volcanic rocks not basaltic in appearance. The description of the 

 fossiliferous rocks overlying the slate leaves no doubt but that they are Tertiary 

 or Recent, a fact which it is difficult to reconcile with Mr. Minard's statement 

 that they are cut by serpentine and diorite. In the placer at the Bigtog, tributary 

 to the Cagayan, Mr. Abella found slightly rounded, large pebbles of orthoclase.' 



"A few miles north\'s-est of Zamljoanga (in southwestern ilindanao), at Caldera. 

 Dana observed hornblendic and talcose schist in pebbles,' and on ilalanipa, about 

 1.3 miles E. by S. from Zamboanga, the Clmllenger expedition collected serpen- 

 tinized peridotite, studied by Mr. Renard." " 



III. GENEKAL GEOGRAPHIC DESCRIPTION AND ITIKERARY. 



The main body of the Philippine Archipelago is connected with Borneo 

 b}' two parallel chains of islands, one consists of Busuanga, Linapacan, 

 Palawan and Balabac, while the other extends southwest from the Zam- 

 boanga Peninsula, comprising Basilan, Sidu, Siasi, and Tawi-Tawi. The 

 inference is that there has been entire land connection at some time in 

 the past. This question will be referred to in a future chapter, at this 

 place it is sufficient to state that there are some objections of a very 

 reasonable nature to such a conclusion. 



The Sulu Group and Mindanao together possess a rough likeness to 

 a long-handled dip23er, the Sulu Islands and Zamboanga Peninsula con- 

 stituting the handle, the eastern part of Mindanao the bowl. Mindanao 

 is marked by its great number of liays and gulfs, its two great rivers, 



'Mission aux lies Phil. (1879-1881), 272-277. 



'Bull. Soo. geoh France (1874), V, 2, 403-406. 



'Mem. acerea de los criaderos auriferos . . . Misamis (1879). 4, 18, 32. 4.5. 



■ V. S. Expl. Exp. (1849). 10, 539. 



' Ibid. 



