82 TRANSACTIONS OF THE [Nov. 20, 
justify speaking of two veins, a zincite vein and a franklinite 
vein. Both are irregular, and pinch from the coming in of the 
foot wall. The ore body is an impregnation of the limestone 
along this horizon with the ore bearing minerals in greater or 
less degree, and with a richer streak in zinc, next the hanging. 
As much as twenty feet in width have been taken out, the walls 
then being too lean to work. Along the back vein at the bend, 
the rock is very complicated and far from a simple limestone. 
The outline of the bend we are obliged to take from the Report 
of the N. J. Survey for 1868. At present only a great pit ap- 
pears, entirely mined out as an open cut, and about 50 ft. deep 
by 100 ft. or more east and west, and 75 ft. north and south. 
The walls show masses of silicates, often beautifully crystallized, 
including augite, jeffersonite, hornblende, garnet, apatite, ga- 
HIGHWay 
Wacker Riy 
SECTION DD & 
Fic. 2. Cross-SECTION CF THE ORE-BOoDY AT OGDENSBURGH. 
For Explanation of Signs, see Fig. 4. 
lena, enormous crystals of franklinite, etc. There are also 
bunches of dark syenitic rock, that are quite certainly intrusive 
in their nature and contain orthoclase, a little plagioclase, green 
hornblende, some augite and garnet. Somewhat northeast of 
this great open cut, and directly between the front and back 
veins, is another open cut. This formerly contained a deposit 
of calamine that was worked out in 1876, and that is described 
by Mr. Marshall, superintendent of the mine, as terminating ina 
bowl-shaped end. Much decomposed limestone thickly charged 
with franklinite is here, so that it would seem as if the interven- 
ing rock between the two veins was impregnated with frankli- 
nite, that it suffered surface alteration and that in a cavity 
secondary calamine formed. 
The report of 1868 states that the ore pitches downward at 
an angle of 65° to the north. Coupling this with the fold, the 
