GEOLOGICAL RECONNAISSANCE OF LEYTE. 351 



About 1 kilometer to the west of Tanauan the United States Army 

 opened a quarry in an isolated hill, in order to obtain stone for repairing 

 the road from Tanauan to Dagmi. There is exposed in this quarry a 

 squeezed, slickensided and very much altered rock which under the 

 microscope showed only serpentine. 



In the falls of the Milarong Elver to the west of Palo, and also in 

 the hill near by, there is exposed an augite andesite with gabbroic texture. 

 It is similar to the rock which is found cutting the schist south of Ta- 

 nauan. The road nearer Palo cuts into a hill of altered shales. At Palo, 

 at the north end of the bridge, a quarrj' has been opened for road material 

 in a high hill of hard and slickensided and somewhat altered shale. The 

 abutments of the bridge rest on exposures of this rock which produces a 

 small fall in the river. The main area of the northeastern district was 

 not visited, but such gravels as were seen from its streams indicate that 

 the rocks which constitute it are similar to those found in the hills which 

 form its southern continuation. The geologic history' of the district, as 

 may be interpretated from the data now available, indicates that the 

 mountainous structure was due to the intrusion of igneous rocks into a 

 series of sediments producing an uplift along an axis trending ap- 

 proximately north 30° west. 



A peninsular part of Samar and the very irregular shaped Darara 

 Island, as well as other lesser islands, lie to the northward, in strike with 

 the northeastern district of Leyte, a fact which indicates that the structure 

 continues to the northward. In traveling by steamer from Catbalogan, 

 Samar, to Carigara, Leyte, and returning from Tacloban through the 

 straits and interisland passages to Catbalogan, an opportunity was given 

 to see the islands at close range, but no landing was made. The islands 

 consist of sedimentary rocks with some igneous rocks which appear to form 

 the axis of the trend, and, if they are not a continuation of the igneous 

 rocks of northeastern Leyte, they at least follow parallel structural lines. 

 Witliout landing and making a close examination it can not be determined 

 whether they are intrusive or not, but the sedimentary beds do not appear 

 to be altered and probably represent a younger formation than those which 

 are cut and metamorphosed by the intrusives of the northeastern district 

 of Leyte. In fact, at Tacloban, in the point of the peninsula on which 

 the town is built, there are some low hills around which the Army post 

 is located and exposures made by cutting roads show that the formation 

 of which these hills are composed is a series of variable sandstones, shales 

 and conglomerates, dipping at a low angle to the eastward. In the con- 

 glomerates there are pebUes and small boulders of igneous rocks which 

 apparently had their origin in the northeastern district. Especially sig- 

 nificant are the pebbles of schist. The hills in Tacloban were once islands, 

 and they have l^een united to the mainland by a recent formation con- 

 sisting of marine deposits and coral reefs whicli form the neck of the 



