Genetic and chemical relationships between berthierine, chlorite and cordierite in nodules associated to granitic pegmatites of Sierra Albarrana (Iberian Massif, Spain)
Article Abstract:
Berthierine is a somewhat stable intermediate in the transformation of cordierite to cordite. The evolution of cordierite to chlorite was examined by electron microprobe analysis of chlorite and berthierine phyllosilicates in granitic pegmatites from the Sierra Albarrana, Spain. There is a metastable phase in the pegmatites when both the minerals are present in the same samples. When cooling of the pegmatites is slow, all the cordierite is converted to chlorite and berthierine is not formed. But when cooling is fast, the conversion of cordierite to chlorite is incomplete and berthierine is formed.
Publication Name: Contributions to Mineralogy and Petrology
Subject: Earth sciences
ISSN: 0010-7999
Year: 1995
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Interstratification and other reaction microstructures in the chlorite-berthierine series
Article Abstract:
Transmission electron microscopic studies reveal interstratification and other reaction microstructures in the chlorite-berthierine series from the metamorphosed ironstones of the Beartooth Mountains, Montana. The antiphase domain structure suggests that the interstratification is the intermediate result of the cell-preserved phase transformation from berthierine to chlorite. Reaction mechanisms and the associated microstructures for the chlorite-serpentine series are analyzed. Berthierine is considered to be a polymorph of the Fe-rich chlorite mineral chamosite.
Publication Name: Contributions to Mineralogy and Petrology
Subject: Earth sciences
ISSN: 0010-7999
Year: 1996
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Low melt fraction connectivity of granitic and tonalitic melts in a mafic crustal rock at 800 degrees celsius and 1 GPa
Article Abstract:
The consistency of the dihedral angle measurements, which yield median apparent theta values of 53 to 58 degrees for an amphibole-rich rock/granitic melt system and 46 to 48 degrees for an amphibole-rich rock/tonalitic melt system, played a vital role in attaining the melt connectivity at 800 degrees celsius and 1 GPa. The dihedral angle measurements derived also showed consistent parallelism with the outcome of diffusion-couple experiments. Such results illustrate melt connectivity at melt fraction less than 4 wt% (<5 vol%).
Publication Name: Contributions to Mineralogy and Petrology
Subject: Earth sciences
ISSN: 0010-7999
Year: 1999
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