Gaological Society and A. A. A. S. Meetiii'js. — UphtDii. 241 
Heated water and steam would appear to be the principal agents of 
metamorphisin, rather than heat alone, since the great distance to 
which recrystallization has reached seems dependent on the porous 
character of the rock before alteration. Garnet, vesuvianite, woUaston- 
ite and pyroxene are among the minerals develofjed, and large crystals 
have been found at a distance of several hundred feet from the contact. 
Prof. Emerson, in discussion, complimented the author on his having 
modestly refrained from proposing new names for these eruptive rocks. 
Syenite-gneiss {leopard rock) frotu, the Apatite Region of Ottawa 
county, Canada. C. H. Gordon, BeJoit, Wis. (Read by title.) The 
rock here described appeared in the exhibit of the Canadian Geological 
Survey, at the World's Fair, under the title of "Concretionary Vein- 
stone," from the apatite region. It consists of irregular ellipsoidal or 
ovoid masses of feldspar, with some quartz, separated by narrow, an- 
astomosing bands of interstitial material consisting chiefly of green pyr- 
oxene. The ellipsoidal masses are of all sizes up to two or three inches 
in cross section and several inches long. The field study at High Rock 
mine, Ottawa county, shows the rock to occur in dikes intersecting the 
pyroxenites and quartzites. In some places the rock is very coarse, 
with no indications of the ellipsoidal structure, while in others it is a 
distinctly banded gneiss whose identity with the ellipsoidal rock is evi- 
dent from the anastomosing of the augite bands on a cross fracture face. 
Ordinarily the rock has very little quartz and corresponds to a pyrox- 
ene-syenite, but in some places the quartz is much more abundant, thus 
allying it to the pyroxene-granites. In view of its gneissic structure and 
usually sparing amount of quartz, the rock is here referred to generally 
as syenite-gneiss, though grading locally into forms which may more 
fittingly be regarded as granite-gneiss. 
The presence of a distinct gneissic microstructure, taken in connec- 
tion with other facts, appears to establish the conclusion that the pecu- 
liar ellipsoidal structure is due to orographic forces acting upon a 
coarsely crystallized rock in which the ijrincipal constituents (feldspar 
and pyroxene) are more or less irregularly distributed. The breaking 
of the rock under pressure has been attended by the recrystallization of 
the augite and other constituents along the original fracture planes, 
which were probably, in part, determined by the arrangement of the 
two chief constituents. 
The points of interest Virought out in the study are: (1) that this pe- 
culiar distribution of the pyroxene is due to dynamic processes, (2) the 
importance to be attached to the process of solution and recrystalliza- 
tion in the formation of gneisses, (3) the significance of the original 
character of the rock with reference to the product derived from it by 
dynamic processes, and the differences resulting from variations in the 
extent to which it has been affected Vjy orographic agencies, and (4) the 
evidence showing the derivation of a gneiss out of a syenite, and estab- 
lishing the term syenite-gneiss as the name of a distinct rock type. 
The Titaniferous Iron Ores of the Adirondaclcs. J. F. Kemp, New 
York City. The paper opened with a brief statement of the characters 
