Review of Recent Geological Literature. ' 187 
The Composition of Kulaite. By Henry S. Washington. (Jour. 
Geol., 8, 610-620.) 
Kulayte is the name given by the author several years ago to a 
subgroup of the basalts in which hornblende occurs as an essential con- 
stituent and surpassing augite in quantity and importance. The orig- 
inal analysis by Rohri^ showed, for basalts, abnormally high soda, as 
well as very high alumina and low magnesia. There seemed to be no 
mineral present which would account for the high alkalis, and to de- 
termine this and other points two new analyses were undertaken, one 
of normal kulayte, and the other of a leucite kulayte. The first showed 
in comparison with Rohrig's analysis, about two per cent, more Fe^O^ 
and as much less K^O ; and the second differed rather widely except for 
the MgO, CaO and Al^O^. It is surprising to find that all these dif- 
ferences are regarded as probably due to the different anal3rtical 
methods used. The normal and leucite kulaytes are found to agree 
closely except in the minor constituents TiOg and PgO. ; and the author 
next considers the place in the classification indicated by this composi- 
tion. The alkalis and alumnia are shown to be high for a true basalt; 
and for these reasons and also becuse of the higher SiO, and the lower 
iron oxides, MgO and CaO, they cannot be referred to the subgroup of 
hornblende basalts. They are, in fact, properly leucocratic, while the 
hornblende basalts are melanocratic; and the closest analogues of the 
Kala rocks are to be found among the nepheline-tephrytes and the 
nepheline-basanytes, notwithstanding that many of these are markedly 
lower in SiO„, AI2O,, and Na,0. A resemblance to the monchiquytes 
is also noted, the main difference being the higher H,0 content of the 
latter. Except in the glassy varieties, the essential hornblende has been 
partially or entirely altered to hypersthene, diopside and magnetite, 
The component minerals are calculated from the analysis, and 
nepheline, the presence of which was indicated by the gelatinization 
and fuchsine tests, is fully confirmed. Certain anomalies of the miner- 
al composition, such as a large proportion of orthoclase in the more 
basic type, and of leucite in the type running highest in SiO„ and low- 
est in K^O, are explained by reference to difference in pressure and 
rate of cooling; and the author favors basing the classification of this 
and other rocks directly upon the chemical composition. w. 0. c. 
A Topographic Study of the Islands of Southern California. By W. 
S. Tangier Smith. (Bull, of the Department of Geology, Univer- 
sity of California, vol. 11, pp 179-230, 1900.) 
The islands described in this bulletin were studied principally from 
maps, and the conclusions reached are intended to be rather pre- 
liminary and suggestive than final in character. The topographic fea- 
ture of the islands are outlined and a general discussion given of the 
characteristics of the various kinds of shore terraces and of the con- 
ditions leading to their formation. 
There follows an interesting account of the oscillations of the Pa- 
cific coast in Miocene and Pliocene time. The information in this ac- 
count is not new. The principal point which the present paper aims to 
