106 ADAMS. 



the same locality. The samples designated as from the Lanatin River, town 

 of Bosoboso, Province of Morong, showed 66.08 per cent metallic iron; the other 

 from Santa Inez, town of Bosoboso, Province of Morong, showed 53.41 per cent 

 metallic iron. The reference to Bosoboso probably accounts for the subsequent 

 statement by McCaskey in his Fifth Annual Report that there are deposits of 

 iron in Bosoboso. 



In visiting the Lanatin deposits the writer journeyed by the way of 

 Bosoboso, past the deserted settlements of San Jose, San Isidro, and 

 Santa Inez. At Santa Inez there are small bowlders of iron ore in the 

 river, and the remains of the abutments of a suspension bridge are in 

 part constructed of bowlders of iron ore. Bowlders of iron ore, some of 

 which are from 2 to 3 meters in diameter are encountered about one 

 hours walk up the river in the bed of the stream. The mountain to the 

 west of the river was evidently the source of these masses. The lower 

 slope of the mountain was ascended along the bed of a stream which 

 empties into the river just above the bowlders. The • country rock 

 exposed by erosion is an andesite containing numerous small specks of 

 pyrite, and in some places bunches of pyrite were found in sheer zones. 

 The larger masses of pyrite were partially altered to hematite. In 

 places there is a small amount of chalcopyrite present and the altera- 

 tion has given rise to a coating of the blue and green copper carbonates. 

 The copper ores have been prospected lately, but have not been found in 

 encouraging quantities. On the wall of the ravine, a face of rock was 

 seen which showed a considerable amount of iron ore, coating and replac- 

 ing the country rock. This has somewhat the appearance of a dyke 

 running up the mountain, although there is no proof that it is, since 

 the dense vegetation obscures the formation excepting in the walls and 

 bed of the ravine. Near the top of the hill there is an outcrop of iron 

 ore. The summit of the hill is capped by a heavy bed of limestone such 

 as is frequently met with in the eastern cordillera. In descending, 

 exposures of a metamorphosed fine-grained clastic rock were seen in 

 the bed of the ravine to the south of the one which was followed in 

 ascending. This rock contains specks of pyrite, but no bowlders of 

 hematite were seen. A simple and sufficient explanation of the origin 

 of the iron ore is that it has been derived from the pyrite which is found 

 disseminated in the country rock and occurring as masses in the sheer 

 zones. It is probable that the mineralization is a result of contact 

 phenomena resulting from the intrusion of the andesite- in the sedi- 

 mentary formation. 



The amount of iron ore is sufficient to supply a small furnace operating 

 as a local industry, and utilizing charcoal in smelting, but there is at 

 present no exposure of an ore body which would warrant the establish- 

 ment of a large furnace. 



It should be remarked here that the prospectors who examined this 

 locality report another iron deposit somewhat more promising at a 



