186 ~=—s .:zD. Dana— Geology of Vermont and Berkshire. 
informed by Mr. R. Van Buskirk, who is in charge of the mine, 
that this ‘‘ white ore” has been taken also from the west side of 
the pit. There is also an outcrop of limestone in the ore-pit in 
which some of the layers are changed to limonite, while others 
above or below are unyielding—the presence of iron in any 
layers of the limestone (as an iron-calcium carbonate) determin- 
ing their destruction. 
t the Cone ore-pit, one and a half miles north of West 
Stockbridge, mining is done mostly through shafts; only at 
the north end is open mining going on so that the structure of 
the walls can be studied. At this end of the pit, limestone 1s 
in view having an eastward dip of 40° to 50°; and while some 
of the layers are not much altered, others are wholly changed 
to limonite. At my last visit (in 1875) the work was going on 
in this stratified material, the limonite portion being selected 
out for further separation by washing. Soveial layers had be- 
18 come wholly replaced by pure limonite, 
ye and one of those so changed was a yard 
were intersected by cracks, making areas 
\. three to six inches across, as represented . 
7g in fig. 18; each crack having a border 
 ~ of limonite either side, an inch or so 
= wide. 
The schist near by—hydromica slate—was in part firm, and 
in other places turned to soft grayish or yellow clay—an 1m- 
pure kaolin—which was silvery in surface from traces of the 
original mica of the slate. The quartz veins in the hydro- 
mica slate remain of course unchanged, in the ores. 
Tie Cheever ore-bed, in Richmond, has also afforded some 
massive carbonate of iron, but less abundantly than the Leet 
ore-bed ; and here, as already stated (p. 135), there is a limestone 
ledge near the pit. : 
Professor EK. Hitchcock mentions the occurrence of massive 
carbonate of iron in Richmond, in his Report on the Geology 
of Massachusetts (1841), page 190, and gives an analysis show- 
ing that it contains 87°19 per cent of carbonate of iron, 5°21 
carbonate of magnesium, 2:46 carbonate of manganese, 141 
carbonate of calcium, and 2°81 of silica, alumina, ete. =99°09- 
The particular ore-bed in Richmond affording it is not stated, 
but it was probably the Leet ore-bed. In the Vermont Geo- 
logical Report (1868), p. 286, Prof. E. Hitchcock gives an analy- 
sis of a dolomite from the vicinity of the Brandon ore-b 
- which afforded 3°61 per cent-of carbonate of iron; and states 
that east of the bed another limestone was quarried for a flux 
which contained ‘10 per cent of iron” [carbonate ?]. 
The limestone has occasionally a little pyrite disseminated 
