Alteration of basaltic glasses from north-central British Columbia, Canada

Journal Article · Mon Oct 01 04:00:00 EDT 1990 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(90)90004-5· OSTI ID:6162216

Jercinovic, M J ^[1]; Keil, K ^[2]; Smith, M R; Schmitt, R A ^[3]

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1. Univ. of New Mexico, Albuquerque (USA)
2. Univ. of Hawaii at Manoa, Honolulu (USA)
3. Oregon State Univ., Corvallis (USA)

Evidence of palagonitization is seen on all glasses studied from three Pleistocene subglacial volcanoes in north-central British Columbia, Canada. Samples from foreset breccias of Tuya Butte are more highly palagonitized than those from the tephra cones of Ash Mountain and Southern Tuya. Extensive palagonitization is generally associated with authigenic mineralization (clays, zeolites). Palagonite composition varies widely relative to glass composition, and palagonite can be broadly categorized as either high-Al or low-Al, depending on whether Al was retained or lost to aqueous solutions during palagonitization. Loss of Al during palagonitization is related to closed-system alteration, including precipitation of aluminosilicate authigenic cements. Microenvironment appears to be more influential than macroenvironment in determining the composition of palagonite. Palagonite rinds are compositionally zoned, generally becoming progressively higher in Al and Ca, and lower in Fe and Mg, towards the innermost (later-formed) portions of the rinds. Phillipsite is the first zeolite formed, followed by chabazite. Analcime and calcite occur in the most highly palagonitized samples. Mass balance considerations indicate higher mass loss where palagonitization has not proceeded to the point where zeolite solubility limits were attained in the local solution. Zeolites occur in closed-system conditions (low flow rates), where little net system mass loss or gain has occurred. The colloidal nature of palagonite allows the effective adsorption of Rb, Cs, Sr, Ba, and REEs.

• OSTI ID: 6162216
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Journal Name: Geochimica et Cosmochimica Acta; (USA) Vol. 54:10; ISSN GCACA; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
AMORPHOUS STATE
BASALT
BRITISH COLUMBIA
CANADA
CHEMICAL COMPOSITION
CHEMISTRY
CLAYS
DISSOLUTION
EARTH CRUST
GEOCHEMISTRY
GROUND WATER
HYDROGEN COMPOUNDS
HYDROTHERMAL ALTERATION
IGNEOUS ROCKS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MATERIALS
MINERALIZATION
MINERALS
NORTH AMERICA
OCEANIC CRUST
OXYGEN COMPOUNDS
PRECIPITATION
ROCK-FLUID INTERACTIONS
ROCKS
SEAWATER
SEPARATION PROCESSES
VOLCANIC ROCKS
WATER
WATER CHEMISTRY
WEATHERING
ZEOLITES