CaCl[sub 2]-NaCl-H[sub 2]O fluid inclusions in the Box Vein of Lyonsdale,NY a fossil shield brine in northern, New York

Conference · Mon Mar 01 04:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5768939

Garside, A R; Darling, R S ^[1]

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1. State Univ. College, Cortland, NY (United States). Dept. of Geology

The Box Vein of Lyonsdale, NY is characterized by calcite-hosted, box-like cavities (equidimensional to tabular in shape) lined with comb-structured quartz. Quartz deposition was followed by late calcite, rare chalcopyrite, and solid organic matter (similar to anthraxolite associated with Herkimer quartz). The geologic setting of the vein is similar to Rossie-type veins in that it is hosted by Precambrian gneisses, but postdates Grenville metamorphism. Primary fluid inclusions in quartz (defined by growth zones) contain H[sub 2]O (vapor) + H[sub 2]O (brine) at room temperature. Upon warming from liquid nitrogen temperatures ([minus]196C), the ice and salt-hydrates gradually darkened and became granular between [minus]65C and [minus]52C, temperatures and phase behavior consistent with first melting in the CaCl[sub 2]-NaCl-H[sub 2]O system. Final ice melting temperatures average [minus]25.2C [plus minus] 1.4C (1 [sigma], N = 9). Final hydrohalite melting temperatures average [minus]13.2C [plus minus] 2.9C (1 [sigma], N = 6). Hydrohalite was distinguished from ice by its higher birefringence and lower relief. Inclusions homogenized to liquid at temperatures averaging 151C [plus minus] 7C (1 [sigma], N = 17). The microthermometric measurements were recorded by temperature cycling. Final melting temperatures of ice and hydrohalite indicate NaCl and CaCl[sub 2] contents of 17 [plus minus] 0.5 and 9 [plus minus] 1 wt. %, respectively (as modeled in the ternary CaCl[sub 2]-NaCl-H[sub 2]O system). The geologic setting, saline fluid chemistry, and relatively low temperature ([approximately]150C) of the Box Vein are similar to characteristics of shield brines described by Frape and Fritz in Canadian basement rocks.

• OSTI ID: 5768939
• Report Number(s): CONF-9303211--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 25:2
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
BRINES
CALCITE
CARBONATE MINERALS
CHEMICAL COMPOSITION
CHEMISTRY
DEVELOPED COUNTRIES
GEOLOGIC AGES
GEOLOGIC FORMATIONS
GEOLOGIC HISTORY
GNEISSES
INCLUSIONS
METAMORPHIC ROCKS
MINERALS
NEW YORK
NORTH AMERICA
OXIDE MINERALS
PHASE STUDIES
PRECAMBRIAN ERA
QUARTZ
ROCKS
USA
WATER CHEMISTRY