264 The Philippine Journal of Science 1922 
some dark mica; also feldspar and white and dark scales of mica. On 
the Salta Sangley, farther south, occur blue-gray clay banks made up of 
sandy, greenish layers which contain the same minerals. In the river 
starting farther south and near Salta Sangley and flowing from the 
rectory at Tragbukan to Calbayog, are found soft, rounded bowlders of a | 
badly weathered rock, coming from the headwaters of the river. In it are | 
recognized white, and some dark, mica and it contains, after washing the 
clay away, a sediment of, in part, ferruginous quartz, feldspar, and some 
magnetite. Accordingly, these bowlders probably come from a gneiss or 
feldspar-rich mica-schist. 
Farther downstream below the Tragbukan chapel there appear again 
green and brown, ferruginous sandstones, slightly consolidated, and made 
up of coarse grains, and having the composition already mentioned. 
This relationship shows that these banks, as those above mentioned, came 
from a weathered gneiss or feldspar-rich mica-schist. In all these clay 
and sandstone strata there is no larger fragment of rock which would 
throw more light on the subject. 
Still farther downstream are brown, fine-earthy, compact, calcareous 
clay banks, with indistinct petrifactions. The residue after treating 
with hydrochloric acid, shows only some scales of mica and quartz grains. 
Farther southeast on the coast near Catbalogan and on the neighboring 
Mojava Island appear volcanic tuffs. These are rather compact, slightly 
clayey, coarse-grained, and greenish gray in color. They contain, besides 
numerous fragments of augite, some rounded crystals of this mineral, 
much magnetite, white feldspar, and some pieces of stone which are the same 
as some of the foregoing larger fragments of rock. The gray, thick, compact 
rock contains in a feldspathic groundmass much green augite and separate 
crystals of magnetite. After treating with boiling hydrochloric acid, the 
groundmass becomes white and is strongly attacked. This behavior and 
the very small number of small triclinic feldspar crystals "show that the 
rock has come from a porphyritic dolerite or pyroxene-andesite. A rounded 
bowlder taken from the same block of conglomerate carries green augite 
in the thick brown groundmass. The numerous round cavities are filled 
with stilbite and opal; the tuffs have a hardness of 2.5 and dip 80° north. 
At Catbalogan we find gray and brown banks, which are somewhat 
argillaceous, partly consisting of very fine sand. The powder yields mag- 
netic iron to a magnet. They (the banks) sparingly contain triclinic 
feldspar, augite, and fragments resembling pumice, sometimes also frag- 
ments of a very. dark, thick rock in which can be recognized single triclinic 
feldspar crystals. In connection with the origin of Mojava, these for- 
mations may be considered as derived from doleritie rocks. 
These banks were in part overlain by a layer of soft, yellowish gray, 
fine-grained limestone. The latter, on treatment with hydrochloric acid, 
leaves a residue consisting of numerous clayish particles, some feldspar, 
augite, and magnetic iron, and small, gray particles of stone; in part, 
calcareous sediments, which have a hardness of 5 to 5.5 and dip 35° north, 
and are thick, compact, and light gray in color. The lower layers are 
mixed with voleanic tuff and calcareous sediment. 
Close to the seacoast near Paranas [Wright] to the east of the bay, 
one notes a hard shell breccia; that is, shell fragments cemented with lime, 
in large, crushed bowlders lying on softer banks of the same material. Out 
