LXQIEILINCIA THQUNS. 235 
Kemp’ describes the gabbros of the western shore of Lake Cham- 
plain. The rocks occurring in this area comprise: (1) gneisses, (2) 
crystalline limestones, including black hornblendic and pyroxenic 
schists and gneisses, and (3) anorthosites, including gabbro proper, 
olivine-gabbros and uorites. The anorthosites over large areas have 
been profoundly affected by dynamic action, and in many places now 
have a gneissic structure. In the anorthosites at various places and 
particularly at Split Rock Mountains, forming the more basic crystal- 
lization from the original magma, are lean, titaniferous magnetites which 
have been mined as iron ores. At the contacts of the gabbro and 
limestone the latter rock has been bent by dynamic movements; vari- 
ous silicates have developed within it, among which are scapolite, horn- 
blende, pyroxene and titanite. The limestone is also coarsely crystal- 
line. Since the intrusion of the gabbro the limestone has been sub- 
jected to dynamic movements, and exhibits strongly the characteristic 
plasticity of this rock under stress. 
Kemp and Hollick’ find the granite at Mounts Adam and Eve, 
N. Y., to be intrusive within the limestone. Adjacent to the granites 
the limestone is white and crystalline and is charged with peculiar 
contact minerals. This white limestone graduates into blue limestone 
with transitional graphitic forms. The continuation of this limestone 
in New Jersey contains Cambrian fossils. 
Nason? finds as a result of analyses that the white and blue lime- 
stone of Sussex county, N. J., are essentially the same in composition, 
both being magnesian limestones or true dolomites. The coarsely 
crystalline white limestone near its contact with granite is generally 
non-magnesian. 
Nason‘ gives a summary of facts showing that the white limestone 
of Sussex county is of Cambrian age, as follows; 
*Gabbros on the Western Shore of Lake Champlain, by J. F. Kemp, Bull. Geol. 
Soc. of Am., Vol. V., pp. 213-224. 
?Granite at Mounts Adam and Eve, Warwick, Orange County, N. Y., and its Con- 
tact Phenomena, by J. F. Kemp and ARTHUR HOLLICK, Annals of the New York Acad. 
Sci., Vol. VII., pp. 638-654. 
3The Chemical Composition of some of the White Limestones of Sussex County, 
N. J., by FRANK L. Nason, Am. Geol., Vol. XIII., No. 3, pp. 154-164, March, 1894. 
4Summary of Facts Proving the Cambrian Age of the White Limestones of Sus- 
sex County, New Jersey, by F. L. Nason. Am. Geol., Vol., XIV, No. 3, pp. 161-168, 
September, 1894. 
