382 SMITH. 



{maciiio) and an impure sandstone formation vrhich he termed molasa. 

 The limestone of this coimtry is quite cavernous and has ahundant stalag- 

 mites and stalactites. Abella found he was tmable to determine specifi- 

 cally one fossil which he found, but he believed it to belong to the genus 

 TurbinoUa. On the basis of this and lithologic evidence, he classified 

 the limestone marls, conglomerates, etc. of this region as Miocene, which 

 I think is quite reasonable. TTpon the hills near the larrios of Munique, 

 Quiliut, and Tagiptip, he found some boulders which axe white and of 

 cellular structure. At first he thought these were limestone, but on closer 

 examination they appeared to be of a feldspathic material with secondary 

 crystallization in the pore spaces, probably zeolites, and with all the other 

 characteristics of modern volcanic rocks. To explain the presence of 

 these rocks, Abella thought that in the moimtain chain to the south and 

 southwest there existed a crater which at a former period threw these 

 volcanic bombs out over the eountr}\ He also noted a very important 

 feature, namely, that there is a lineal regularity in the volcanic mani- 

 festations, as the line connecting the recent volcano of Camiguin and of 

 Apo and Batulong passes through this region, and he thought this con- 

 firmed his supposition. 



Abella's general conclusions regarding this region were as follows : 



GEXEBAL DEDUCTIONS. 



As a restilt of the observations wliicli I have just given, there appear to be only 

 three perfectly distinct formations considered petrographically and stratigra- 

 phieally,. shales more or less metamorphosed, marls, and alluvial deposits. Among 

 the last mentioned, one distinguishes between the auriferous and the barren or 

 poor, not only by its different composition and richness, but especially by the 

 relative age of the two deposits, confirmed by the examination of the beds of 

 the streams which cut across the placers. 



In reality, however closely the ancient streams which produced the placers 

 followed, with slight variations, the present river valleys, tracing out, so to speak, 

 the modem hydrography, it is certain that this alluvial action has become much 

 weaker, and I have no doubt but that the surface streams have been greatly 

 reduced in voltune and that the earlier deposits in part have been destroyed by 

 the erosion of the water carried in the present channels, the sands of which also 

 contain gold, but from a source and in occurrence very different from the ancient 

 placers. The gold which one finds in these comes from deposits in rock which 

 must be situated in the interior, and upon which the alluvial action worked with 

 energy, loosening, transporting, and depositing its materials to a greater or less 

 distance. The gold contained in the beds of the present rivers has come from the 

 destruction which they produced and still produce in the auriferous alluvions 

 deposited previously, and only, perchance, in the highest parts of the present 

 streams of greater importance is there to-day even a small amovmt of erosive 

 action on the rock deposits cited. 



Therefore. I believe there are sufficient reasons for making this distinction 

 between those which can be called ancient, the primitive placers, and those which 

 I should designate as recent, which have formed and continue to form the beds, 

 valleys, and beaches of the present topography of the country. 



As the greater part of the auriferous alluvions lie above the deposits overlying 



