362 The American Naturalist. [April, 
PETROGRAPHY- 
Some Basalts of Asia Minor.—The rocks near Kula, Asia 
Minor, are basalts in sheets and lava streams, the latter emanating 
from a number of old volcanic centers whose cores may still be dis- 
tinguished. These basalts, according to Washington,’ are hornblende- 
plagioclase basalts, characterized especially by the abundance of their 
hornblendic component. This mineral, augite and olivine are present 
as phenocrysts in a groundmass made up of plagioclase, magnetite and 
glass, the latter being lighter in color as the magnetite in it increases 
in quantity, thus indicating that this mineral was one of the latest 
separations from the magma. Leucite was discovered in two of the 
streams. It presents no unusual features. The mineral is rare in 
hornblendic basalts elsewhere. None of the components of the rocks 
merit special mention but the hornblende. This is always porphyritic 
and is present in large quantity. Its color is yellow, brown or green- 
ish-yellow, and its extinction varies from 4° to 23°. The chemical 
alterations effected in the mineral by magmatic resorption are inter- 
esting. One effect is the replacement of the hornblende by a reddish- 
brown mineral associated with colorless augite and opacite, and another 
is its partial or complete alteration into augite and opacite. The 
brown mineral is referred to hypersthene, although the analysis of a 
portion of the rock containing a large quantity. of it was rather against 
this theory. The author thinks that the formation of the mineral was 
probably due to the reducing action of hydrogen (from dissociated 
water included in the lava) upon the ferric iron of the hornblende. 
In structure the basalts are normal, hyalopilitic, semi-vitreous and 
tachylitic. An analysis of a leucite variety gave: 
SiO, ALO, FeO, FeO CaO MgO Na,O K,O P,O, H,O Total 
47.74 20.95 329 632 7.56 5.16 7.12 121 18 .04—99.52 
Since the hornblende is of primary importance in the basalts of Kula, 
it is proposed to call them, and other basalts in which hornblende pre- 
dominates over augite and olivine, by the name of Kulaites. 
The Igneous Rocks of the Eureka District.—In an appendix 
to the Geology of the Eureka District, Iddings’ gives an account of 
1 Edited by Dr. W. S. Bayley, nape University, Waterville, Maine. 
2 Amer. Jour. Sci., Feb., 1894, p 
3 Monograph XX U. S. ‘Geol E p- 337. 
