216 CONTRIBUTIONS TO ECONOMIC GEOLOGY, 1902. [bull.213. 
At the Buckwheat mine the ore has been worked from the outcrop 
down nearly 300 feet with the dip, which is very steep to the east, and 
at the Parker shaft workings 1,000 feet from the surface 
The comparison of the structure and extent of the workings along 
the west vein and those of the Parker shaft shows an evident con- 
tinuity of the deposit, dipping steadily downward to the east from 
the outcrop for 1,300 feet, where it begins to rise again for 150 feet, 
when the ore terminates. In the basin thus formed, and also in the 
part forming the eastern edge, there is a great thickening of the ore. 
At the Buckwheat mine the same structure is found, a crosscut driven 
west to the west vein shows that the foot wall of the east vein curves 
around to form the hanging wall of the west vein, the width of the 
ore in the north slope of the Buckwheat mine is about double the nor- 
mal width of the two veins (70 feet in the first, 35 or less in the sec- 
ond), and the limestone forms an arch over the ore, the foliation of 
which, and the structure of the franklinite bands in the limestone 
roof, conforming to the arch of the ore, which pitches downward at 
an angle of 27° to 32°. Putting all these facts together, the inter- 
pretation on which all observers agree is that the east and west veins 
are one continuous plane body of ore folded in a synclinal trough, 
which narrows to the south and finally spoons out at the surface 
in the south chamber workings; less positive is the theory that there 
is a sharp subordinate anticline on the east side, with the two sides 
compressed together and the axis pitching 27° or more to the north- 
east. The fact is plain that there is a thickening of the ore and 
that this thickened shoot pitches northeast at about the same angle 
as the axis of the main synclinal trough or basin. The compass direc- 
tion of this axis gradually curves to take a more northerly direction 
in the Parker shaft workings so as to conform to the strike of the 
west vein. The pitcli also flattens in the north workings to as low as 
0°, and certain facts from the diamond-drill records show that the 
structure is more complicated there, but the data available are too 
fragmentary to permit a definite conclusion. It is noteworthy that 
the pitch of 27° in the Buckwheat mine is also to be seen in the 
gneisses lying just west, an argument for the contemporaneity in 
present form of the gneiss, white limestone and ore deposit. 
In several places in the underground workings at Mine Hill, granite 
or syenite masses cut the ore. In 1898 several of these were studied 
in the Parker shaft workings. They run, like the surface granite 
outcrops, nearly parallel to the general trend of the foliation of the 
vein and yet cut distinctly across it in places. The granite is line- 
grained for several inches from the contact, the ore is hardened for 
some distance, and between granite and ore there is a band of yellow 
(Mn) garnet (polyadelphite) mixed with rhodonite, calcite, willemite, 
franklinite, and a Mn. Zn. pyroxene ( jeffersonite?) ; the granite itself 
also contains stringers and isolated masses of these minerals. Some- 
