254 The Philippine Journal of Science 1922 
the north coast. In 1907, Lieut. Robert Thomas collected three 
rock specimens from northern Samar and submitted them to 
the Bureau of Science with a memorandum of localities. To-day 
only the memorandum can be found. Specimen 1 was a carbo- 
naceous shale which is common in Catubig River Valley. No. 2 
was a diorite (quartz?) found in the bed of Palapag River near 
the town of Palapag. The collector notes: “No stratum found 
anywhere in river bed.” Specimen 3 was a quartz pebble found 
near the mouth of Palapag River. The diorite, it is thought, 
points to a dioritic basement complex of Samar. 
North coast.—Outcrops, probably of post-Vigo formations, at 
Laoang strike approximately east-west and, according to Moody, 
dip north. Farther to the west, near the Catarman Agricultural 
School, strata of shale, sandstone, and conglomerate, with inter- 
gradations, were seen. A specimen of impure sandstone from 
this locality is medium-grained, buff, heavy-bedded, slightly cal- 
careous, somewhat feldspathic, discolored by iron, and composed 
of fairly well-rounded grains. The shale is bluish, weathering 
to buff, while the conglomerate is composed principally of dia- 
base, diorite, felsite, and quartz pebbles, subangular to rounded, 
averaging 1 to 2 centimeters in diameter, embedded in a gritty, 
calcareous matrix. 
On the north coast of Samar, 2 kilometers east of Carangian, 
is an outcrop of a badly weathered, coarse-grained, gray rock, 
which is discolored by iron and speckled with black crystals of 
pyroxene and many fragments of magnetite. The grains are 
not well rounded, and though some augite is present, the prin- 
cipal minerals appear to be quartz and feldspar, making the 
rock an arkosic sandstone or, perhaps more properly, a true 
arkose. I am led to speculate if this formation explains the 
statement made by Becker to the effect that—"' 
In Samar, Jagor found no ancient rocks in place, but sediments which 
he collected on the north coast appeared to Roth to be derived from gneiss 
or mica schist.” 
Moody also collected a specimen of this rock from the same 
locality, but on the beach; it is rich in feldspar and magnetite, 
with a little biotite, and appears to be a badly weathered, holo- 
crystalline, igneous rock; if it is, one could say with some cer- 
tainty that this represents the basement complex of the island, 
“Becker, G. F., Geology of the Philippine Islands, Annual Rep. U. S. 
Geol. Surv. 21° (1901) 493-644. 
“Cf. translation of Roth’s paper, Appendix 1, page 263. 
