34 The Philippine Journal of Science 1922 
must be applied in evaluating the Miocene, Pliocene, and Pleistocene of the 
Torrid zone. | 
Above this formation stratigraphically, but not always topo- 
graphically, are two formations which are probably contempo- 
raneous. One, which comprises the terrace materials along 
Malitabug River, the writer called the Malitabug formation; to 
the other, comprising the elevated coral reefs so well developed 
in that locality, he gives the name of Pikit, These two, he con- 
siders, date from the late Pleistocene. The Banisilan forma- 
tion he assigns to the early Pleistocene or late Pliocene. 
In this region are several types of igneous formations. The 
Babuy Mountains are a great mass of andesite and basalt, and 
on the fianks of these mountains there is considerable andesitic 
agglomerate. These materials, the writer believes, are intrusive 
in the Vigo formation, but not in the Malumbang; that is, they 
are post-Vigo and pre-Malumbang. At the seep on the flanks 
of the Babuy Mountains the oil appears to be issuing along a 
fault plane on one side of a dike which runs out from the main 
mass in an east-west direction. The rock is so badly weathered 
and decomposed (it is also somewhat metamorphosed) that it 
has been difficult to make an accurate petrographic description 
of it. There seems to be no question that it is igneous. On the 
hanging wall there is a very much-broken mass of material which 
may be either agglomerate, locally brecciated igneous rock, or 
merely talus. Thin sections of this igneous rock showed consid- 
erable decomposition and crushing, giving to the section the 
appearance of a volcanic tuff. There are some large crystal 
fragments in the section, principally of feldspar. There is a 
_ Suggestion of clastic texture, but the writer is of the opinion 
that this is secondary. Therefore, it is difficult to state posi- 
tively just what this material is. I¢ appears, however, to be 
a badly crushed andesite or basalt. In an unpublished report 
on this region the opinion is expressed that this seep is located 
along a fault plane in sandstone. Neither the field nor the 
laboratory examination of this rock, in the opinion of the writer, 
justifies this classification. 
Owing to the lack of detailed work in the region, we can give 
only an approximation to the thickness of the various formations 
in this region, and such estimates as we can make are shown 
in Table 1. 
The general distribution of some of these formations is shown 
on the sketch map, fig. 2. From the nature of the topography 
