2 lî. Eotô : 



Referring mainly to the western Pacific, WiCHMANN'Mong ago 

 made known a melilite-nepheline basalt from Oalui in the Hawaiian 

 Islands, and Ceoss^^ has acquainted us with the occurrences of a 

 trachyte (acid phonolite) and a nepheline-basalt from one of the 

 same island group. Alkaline rocks are said to occur in Tahiti, in 

 the Viti Archipelago, and also in Timor^-*; while leucite-basalts are 

 found in Java^\ in the southern Celebes^\ and also in Masbate, 

 one of the Philippine islands*'^ A limburgite is known in the 

 Samoa group, and a nepheline-basalt in the Caroline islands'^-*. 



As to the alkaline rocks of Japan, I noticed some fifteen years 

 ago^^ an allied rock from the Nemuro headland at the east end of 

 Hokkaido, where it is said to occur in the terrane of the Cretaceous. 

 In 1907, I found the same kind of rock occurring in the Shirétoko 

 promontory in Japanese Sakhalin, making a sheet or dyke in the 

 coal-bearing Tertiary. Lately I have received dioritic-looking 

 specimens, sent by Déguchi, from Tendai-san, in the islet of 

 Hattaku-to, in the Pescadores, and from Reisuiko near Taihoku, 

 Formosa. They all proved to be the same kind of rock as that 

 above mentioned. Tbese are doleritic both in mineralogical 



1) Neues Jaltrhich f. Min. etc., 1S75, \i. 172. 



2) Jour. Geol., vol. xii., 1901, p. 510. 



3) E. Daly, " Origin of the Alkaline Eocks." Bull. Geol. Soc. Amer., vol. xxi., 1910, p. 105. 



4) Verbeek et Fennema, " Description géologique de Java et Madoura," 1896. 



5) Harker, " Natural History of Igneous Eocks,'' p. 98. Details are given in W. Bucking, 



" Leucitbasalt aus der Gegend von Pangkadjene in Süd-Celebes." Berichte <1. Nuturforsch. Gessel- 

 z. Freiburg i. Br. Bd. XI. Heft 2, 1899. 



C) Iddings,. " The Petrography of Some Igneous Eocks of the Philippines." Philipinne Jour. 

 Set, section A. (1910) 5, p. 164. 



7) Harker, loc. cit., p. 98. M. Weber recently acquainted us with the occurrences in the 

 Samoa group, of an alkaJi-trachyte, phonolite, trachydolerite, nepheline-basalt and nephelino- 

 basanite besides the visual plagioclase-basalt and andésite. Ahh. h. Bayr. Akad. d. TF/ss. II. Kl. 

 24. II. Abt. 1909, S. 290-310. 



8) " Notes on the Geology of the Dependent Islands of Taiwan." Jour. Coll. Sei. Imp. Univ. 

 Tokyo, vol. xxii., p. 44. 



