The chemistry and mineralogy of a CO sub 2 -rich travertine depositing spring in the California Coast Range

Journal Article · Sun Nov 01 00:00:00 EST 1987 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(87)90364-4· OSTI ID:5180277

Amundson, R; Kelly, E ^[1]

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1. Univ. of California, Berkeley (USA)

A CO{sub 2}-rich (> 1 atm PCO{sub 2}) travertine-depositing spring was studied to determine how it equilibrated, both chemically and isotopically, with conditions at the earth's surface. The water degassed rapidly along a 47 m section of its channel. Small quantities of siderite- and aragonite-rich precipitates were present along the first few meters and larger quantities of aragonite-rich precipitates were present in the later sections of the channel. CO{sub 2} degassing increased the {delta}{sup 13}C of dissolved C from {minus}9.7 {per thousand} near the spring orifice to +0.7 {per thousand} 47 m downstream. Along the first portion of the stream, the isotopic effect of degassing could be explained by a Rayleigh distillation process. Along the latter portion of the stream, photosynthesis may have enriched the dissolved C in {sup 13}C. The carbonate minerals appear to have formed in approximate isotopic equilibrium with the dissolved C. Older travertine samples from the terrace differ chemically, mineralogically, and isotopically from the more recently deposited minerals suggesting a possible alteration of the originally deposited material.

• OSTI ID: 5180277
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Vol. 51:11; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
54 ENVIRONMENTAL SCIENCES
TRAVERTINE
CHEMICAL COMPOSITION
ISOTOPE RATIO
MINERALOGY
PRECIPITATION
WATER SPRINGS
WATER CHEMISTRY
CALCITE
CALIFORNIA
CARBON DIOXIDE
CARBON ISOTOPES
DEGASSING
EQUILIBRIUM
GEOCHEMISTRY
GROUND WATER
SIDERITE
ALKALINE EARTH METAL COMPOUNDS
CALCIUM CARBONATES
CALCIUM COMPOUNDS
CARBON COMPOUNDS
CARBON OXIDES
CARBONATE MINERALS
CARBONATE ROCKS
CARBONATES
CHALCOGENIDES
CHEMISTRY
FEDERAL REGION IX
HYDROGEN COMPOUNDS
IRON CARBONATES
IRON COMPOUNDS
IRON ORES
ISOTOPES
LIMESTONE
MINERALS
NORTH AMERICA
ORES
OXIDES
OXYGEN COMPOUNDS
ROCKS
SEDIMENTARY ROCKS
SEPARATION PROCESSES
TRANSITION ELEMENT COMPOUNDS
USA
WATER
580000* - Geosciences
540320 - Environment
Aquatic- Chemicals Monitoring & Transport- (1990-)