354 ADAMS. 



older Tertiary, which luue lieeii iiietainor|)hosed intu t;ehi8ts and altered 

 shales by intrusive igneous rocks. Some stream gravels indicate that a 

 similar series of more or less metamorphosed sedimentaries and aeeoni- 

 panying intrusives ai'c present in the soutliweslera district. The erosion 

 of these formations has contributed sediments to the later Tertiary. 



The most widely distributed formation is a sei'ies which contains besides 

 conspicuous beds of limestone, some shales, sandstones, and conglomerates. 

 It is the predominating formation in the sqfUthwestern district and is 

 reported to contain coal near Port Calubian (Eulalia) and petroleum 

 north of Villaba. There is a small area of limestone of this series in 

 the hills at Patyacan point on the east side of the Cordillera in the 

 southeastern part of the island, and it is represented in the northeastern 

 part of the island near the strait of San .Juanico, and e.xtensively in 

 southwestern Samar. These sedimentaries are usually considered as later 

 Tertiary. They- have lieen lifted, faulted, and intruded by igneous rocks 

 which appear to be closely, related to the igneous rocks of the Cordillera. 



The Central Cordillera of Leyte is a volcanic belt which e.xtends in a 

 direction north 30° west, through the island and continues in Biliran and 

 Maripipi Islands. It contains the extinct volcano Cabalian, the solfataras 

 south of Burauen, Mount Amandiuing, which is probably an extinct 

 volcano, and the solftaras in Biliran Island. The rocks of this district 

 are largely hornblendic andesites. 



The northeastern plains, which are largely alluvial, represent the latest 

 extensive formation. In addition there are some marginal littoral 

 deposits formed in part of coralline limestone. 



The emergences and submergences of Leyte and the adjacent islands, 

 including especially Samar, form a complicated history. The coal in 

 Leyte (and it may be noted that coal is also reported in western Samar but 

 not yet known to be of economic importance) and the wide distribution 

 of coralline limestone, in what is called the later Tertiary series of sedi- 

 mentaries, indicates an extensive area of low-lying lands, coral reefs and 

 shallow seas in late Tertiary time. The emergence of this series, which 

 formed the Island of Leyte, seems to have been l)rought about by the 

 igneous intrusions and volcanic eruptions which took place in the zone 

 of the Cordillera. During the first stages of this process a strait probably 

 extended in what is now the northeastern plains district. By continued 

 elevation and the contriliution of sediments from the Cordillera this 

 strait has been transformed into an aggraded alluvial area. The develop- 

 ment of the San Juanico Strait apparently occurred later and may be 

 attributed to a submergence along an axis parallel to the Cordillera of 

 Levte, and perhaps resulting concomitantly with the growth in elevation 

 of the centra] portions of the Islands of Samar and Leyte. 



