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

68 REPORT OF THE VERMONT STATE GEOLOGIST. REPORT OF THE VERMONT STATE GEOLOGIST. 69
Totals.
Rutile is present in the eastern part of the formation in
(a.) (b.) minute hairs or threads penetrating the crystalline limestone.
Silicon dioxide, S10 2 ............... 35 .748 35 .748 Perhaps they occur most frequently in Sharon, Vt. The mm-
Titanium dioxide, Ti02 .............. . 190 . 189 eral is the dioxide of titanium, and silicon is often replaced by
Carbon dioxide, CO 2 ............... 22.86o 22 .870 this element of the same quantivalence.
Ferric oxide, Fe 20 3 ................ .010 .010 The unexpected glucinum manifested itself in traces of the
Aluminum oxide, A1 20 3 ............. 6.113 6. 112 mineral beryl, a silicate of glucinum and aluminium which is
Ferrous oxide, FeO ................ .940 .941 abundant in the adjoining heterogeneous terranes of New
Glucinum oxide, GlO ............... .313 .315 Hampshire.
Manganous oxide, MnO ............ .076 .075 Lithium occurs in the lithium aluminium silicate, spodumene,
Barium oxide, BaO ................ .210 .210
f
in the homogeneous terranes in Massachusetts.
Here the mm-
Calcium oxide, CaO ................ 27.305 27.304 eral is so highly developed that commercial lithia may be
Magnesium oxide, MgO ............ 3 .248 3. 244 extracted with profit. Perhaps traces of this element are scat-
Sodium oxide, Na 20 ............... . 186 .187 tered throughout the entire Lower Trenton terranes, for it
Potassium oxide, K 20 .............. .063 .064 occurs in the complex orthosilicate, muscovite.
Lithium oxide, Li 20 ................ .823 .824 Chlorine is probably present in combination with one of the
Water, H 20 ....................... . 108 . 107 alkali metals; and the fluorine with the complex orthosilicate,
Phosphorus pentoxide. P20 3 ......... 1.359 1.359 biotite. Surface samples of biotite yield fluorine in analysis
Chlorine, Cl ....................... . 307 .307 and minute crystals of biotite more or less associated with mus-
Fluorine, F ....................... .026 .026 covite grace the entire formation.
Carbon, C ........................ Microscopical trace As the prevailing constituent is the carbonate of calcium with
enough magnesium present to make it dolmitic, the rock may
99.885 99.892 be known as a silicious marble. It carries a large percentage
Less Oxygen=F & Cl ............... .079 .079 of silicic anhydride and many minute traces of complex silicates.
99.806
Its complexity is so great that a single formula cannot well rep-
99.813
resent its chemical composition. The presence of the rare ele-
100— 9. 8o6 = . 194 difference.
100— 99.813 = . 187 difference. ments has been confirmed by most searching spectroscopic
The presence of so many unexpected elements and compounds,
as well as the large percentage of Si0 2 , may seem difficult
to explain. In fact its complexity of structure is unparalleled
by any analyzed marble. The excessive amount of Si0 2 arises
from two sources: First, the intercallation of granules of sand
analyses.
The carbon is found in microscopic thin sections.
(b.)
Table Showing the Percentage of Solubility and Insoluble Residue
in Washington Limestone.
when the vast calcareous beds were deposited in oceanic waters; NAME AND LOCALITY. SOL. INSOL.RES. SOL. INSOL.RES.
second, the interjection of silicic anhydride in gaseous form Washington in a r b 1 e,
prior to the metamorphosing of the marble. Clough quarry ....... 56.47 43 . 53 56.475 43 . 525