Ca-Mn exchange between grossular and MnCl2 solutions at 2 kbar and 600 degrees celsius: reaction mechanism and evidence for non-ideal mixing in spessartine-grossular garnets
Article Abstract:
The products of the hydrothermal reaction between grossular and 1 molar manganese chloride at 2 kbar and 600 degrees celsius are garnets of the spessartine-grossular solid solution series. Spessartine is the first garnet to crystallize, followed progressively by more calcium-rich garnets. The final product exhibits a two directional Ca/(Ca + Mn) zoning pattern. Linear variations in the plots of the mole fraction of Ca in garnet versus ln K(sub D) suggest a process of non-ideal mixing for these garnets. Thermodynamics of the Ca-Mn exchange and its petrological implications are discussed.
Publication Name: Contributions to Mineralogy and Petrology
Subject: Earth sciences
ISSN: 0010-7999
Year: 1996
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Seawater-sediment-basalt interactions: stable isotope (H, O) and elementary fluxes within the Ordovician volcano-sedimentary sequence of Erquy (Brittany, France)
Article Abstract:
Ordovician volcano-sedimentary rocks at Urquy, France, were formed from marine hydrothermal metamorphosis of sediments by basic sill intrusions and pillow lavas from local volcanism. Metamorphic reactions took place at relatively low temperatures of 200-250 degrees C in seawater, as measured by differences in oxygen-18 isotope levels in sedimentary and volcanic layers. Characteristics of chlorite and albite metamorphosis further corroborate the low temperature of formation.
Publication Name: Contributions to Mineralogy and Petrology
Subject: Earth sciences
ISSN: 0010-7999
Year: 1995
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The stable isotopic evolution of a metamorphic complex, Naxos, Greece
Article Abstract:
A major metamorphic complex covers most of the island of Naxos, Greece. A stable isotope analysis of marble, amphibolites and pelites from an overprinted Miocene-period of metamorphism, designated M2, helps unravel the fluid-rock interactions of pre-metamorphic rocks affected by fluid intrusion. According to this analysis, the lower-grade rocks appear to be of metasedimentary origin and the higher-grade rocks came from igneous precursors.
Publication Name: Contributions to Mineralogy and Petrology
Subject: Earth sciences
ISSN: 0010-7999
Year: 1995
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