Mineral Industries and Geology of Certain Areas - Vermont Agency ...

--__ -
PLATE IXA.
The Terranes of Orange County, Vermont.
DR. C. H. RICHARDSON, DARTMOUTH COLLEGE.
Geological Map of Orange county, with Part, of Washington and Windsor Counties, Vt.
Scale, 10 mIles .=1 inch.
N0TE.—The black area along the Connecticut sliver is Modified Drift.
INTRODUCTION.
The treatment of the terranes of Orange county, Vermont,
records a most searching and ultimate analysis of the Washington
marble, which singularly carries more than one-fourth of
all known elements. It shows the percentage of solubility in
several surface samples of widely different localities. It discusses
the olivine of Corinth, the source of the famous Thetford
limburgite of Dr. Oliver Payson Hubbard. It embodies an
analysis of the arsenopyrite of Braintree and the scales of phyllite
set transverse to the planes of foliation in the shaly terranes.
It presents a geological map of Orange county and protracted
sections across the same, with legends. It gives chapters upon
bibliography, topography, chemistry, geology and paleontology,
accompanied by two maps and thirteen half-tone cuts. It
divides the "Calciferous Mica Schist" of Professor C. H.
Hitchcock into a calcareous and a non-calcareous member; and
carefully designates the former as Washington limestone and
the latter as Bradford schist. It locates these terranes from
1 : paleontological evidence as Lower Trenton, which formerly
have been recognized by American geologists as Upper Silurian.
3 MAPS.
The geological map (Plate IX*) represents the distribution of
heterogeneous terranes lying between the Connecticut River on
the east and the Huronian rocks of central Vermont on the
west. It extends from latitude 430 30' northward to latitude
By an unfortunate error the Granite areas are shown in the same manner as are the
modified drift, but the only drift area is that which borders the Connecticut river, all
the remaining black spaces are granite.