Zonation patterns of skarn garnets: Records of hydrothermal system evolution

Research Article| February 01, 1993 Zonation patterns of skarn garnets: Records of hydrothermal system evolution Bjørn Jamtveit; Bjørn Jamtveit 1Department of Geology, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ, England Search for other works by this author on: GSW Google Scholar Roy A. Wogelius; Roy A. Wogelius 2Department of Earth Sciences, University of Oxford, Parks Road, Oxford OX1 3PR, England Search for other works by this author on: GSW Google Scholar Donald G. Fraser Donald G. Fraser 2Department of Earth Sciences, University of Oxford, Parks Road, Oxford OX1 3PR, England Search for other works by this author on: GSW Google Scholar Author and Article Information Bjørn Jamtveit 1Department of Geology, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ, England Roy A. Wogelius 2Department of Earth Sciences, University of Oxford, Parks Road, Oxford OX1 3PR, England Donald G. Fraser 2Department of Earth Sciences, University of Oxford, Parks Road, Oxford OX1 3PR, England Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1993) 21 (2): 113–116. https://doi.org/10.1130/0091-7613(1993)0212.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Bjørn Jamtveit, Roy A. Wogelius, Donald G. Fraser; Zonation patterns of skarn garnets: Records of hydrothermal system evolution. Geology 1993;; 21 (2): 113–116. doi: https://doi.org/10.1130/0091-7613(1993)0212.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Chemically zoned skarn garnets provide a continuous record of hydrothermal processes in lower Paleozoic sedimentary rocks within the contact aureole around the Drammen granite in the Oslo rift, southern Norway. Major and trace element zonation profiles, the latter obtained using a scanning high-resolution proton microprobe, reveal early infiltration-controlled growth of relatively grossular rich garnets, the major and trace elements compositions being buffered by local mineral dissolution. Subsequent rapid, epitaxial growth of andradite-rich garnet on grossular-rich cores marks the onset of vigorous and focused fluid flow along high-permeability zones. During this later stage, the hydrothermal fluid composition was to a large extent externally controlled, and the andradite precipitating from these fluids was characterized by high As and W contents. The zonation patterns of the andradite-rich garnets record at least five intermittent growth periods, with rapid andradite precipitation from fluid batches with high fO2, and progressively decreasing As and W contents. Thin layers, poor in Fe, As, and W, but relatively high in Al and Mn, represent periods of slow growth rates between the major pulses of hydrothermal fluids. The marked rimward decrease in the As and W contents of the garnets may reflect influx of meteoric waters or exhaustion of these elements in the hydrothermal fluid reservoir caused by boiling-controlled distillation processes at depth. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.