^.-je The American Geologist. December, i904. 
The Philippine Islands: It is unfortunate that we should 
possess so Httle knowledge of the geology of the Philippine 
islands. After six years of occupation by the United States 
the only reports published are those by Becker* which review 
the scattered papers, mainly in foreign languages, which at 
different times have referred, however cursorily, to the geolog>' 
of the Philippine islands. 
Of great interest, however, and especially so because of our 
meagre knowledge, is the collection of ores, minerals, and rocks 
which have been gathered from many sources and placed upon 
exhibition in the Philippine Mines building at the St. Louis 
Purchase Exposition. With the knowledge that valuable de- 
posits of coal (including good steam coal), iron, and copper 
occur in the islands, and that some of these are soon to be 
vigorously exploited, it seems unlikely that the geological ex- 
amination of the islands can be much longer dela)'ed. The 
importance from a strategic as well as from an economic stand- 
point, of developing these deposits it would seem would be 
generally appreciated. For our knowledge of the structure of 
the islands, we are especially indebted to Austrian t and Japan- 
eset geologists. 
In the paper on the island world of southeastern Asia, Koto 
has included a brief section upon the Philippines, which, mea- 
gre as it is, contains important conclusions regarding the areal 
and geologic structure of the islands. In the larger archipel- 
ago of which the Philippines form a part, mountain ranges and 
chains of volcanoes radiate from the inner group, which con- 
sists of the islands of Borneo, Celebes, and Gilolo. These 
mountain ranges comprise parallel ridges, separated by tec- 
tonic valleys, one of which extends from the bay of Butuan to 
the bay of Davao in Mindanao, and another from the bay of 
Lingayen to Manila, so as to separate the main Luzon chain 
from the westerly Zambales. The volcanic zones and the prin- 
* Gborgb F. Bkcker: Brief memorandum on the geology of the Philip- 
pine Islands. U. S. Geol. Snrv., 20th Ann. Rep., pt. ii, pp. 3-7, 1900. 
Gborgb F. Beckbr: Report on the Geology of the Philippine Islands. V. 
S. Geol. Snrv., 21st Ann. Rept., pt. iii, pp. 493-614. This paper includes a list 
of sources and a translation of C. Martin's paper concerning Tertiary Fossils 
in the Philippines (pp. 615-625.) 
t SuKss: Antlitz der Erde, vol. i, 1885, pp. 685-588; vol. ii. 1888, pp. 206- 
217; vol. iii, 1901. pp. 308-332, plate II. 
t Koto: On the geologic structure of the Malayan archipelago. Jour. Coll. 
Sci. Imp. Univ. Tokyo, vol. ii, pt. ii, 1899, pp. 83-120, with plate I. 
