Development of framboidal pyrite in the Upper Permian marly limestone of the NE-Hungarian Darnó Hill

<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; The NE Hungarian Darn&oacute; Hill has a complex geology; it is built up by an accr&eacute;tionary m&eacute;lange complex, which contains Permian, Triassic and Jurassic...

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Main Authors: Gabriella Kiss, Federica Zaccarini
Format: Article
Language:English
Published: Croatian Geological Survey 2013-10-01
Series:Geologia Croatica
Subjects:
Online Access:http://www.geologia-croatica.hr/ojs/index.php/GC/article/view/617
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author Gabriella Kiss
Federica Zaccarini
author_facet Gabriella Kiss
Federica Zaccarini
author_sort Gabriella Kiss
collection DOAJ
description <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; The NE Hungarian Darn&oacute; Hill has a complex geology; it is built up by an accr&eacute;tionary m&eacute;lange complex, which contains Permian, Triassic and Jurassic sedimentary and magmatic blocks too. The succession can be well correlated with the NW Dinarides, and evidences of the different evolutionary stages of the Neotethyan Ocean (rifting, marginal basin opening, closure) were described too.</p><p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Several ore indications are known from this area, but their genesis was by far not well reconstructed, mostly because of the complexity of the geological background. The present study deals with one of these indications found in deep drillings. A framboidal pyrite bearing Permian-Triassic marly limestone series was investigated, which was described earlier as a possible analogy of the Polish-German copper shales (<em>Kupferschiefer</em>).</p><p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Based on detailed microscopic, EPMA and whole rock geochemical analyses, it was found, that besides the framboidal pyrite, euhedral pyrite overgrowths (both contain high amount of Au), disseminated euhedral and anhedral pyrite (which do not form framboids or overgrowths), anhedral chalcopyrite, galena and sphalerite were also found, causing a slightly enriched total metal content of 100-200 ppm. The minerals were formed under reducing, anoxic marine conditions, in more steps; after the synsedimentary processes, sulphides formed during early diagenetic/hydrothermal processes too. The found characteristics are typical to the weakly mineralized type of the <em>Kupferschiefer</em>.</p>
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spelling doaj.art-d78c2fd643a5414c8bfbf51d6e54d41f2022-12-22T00:42:26ZengCroatian Geological SurveyGeologia Croatica1330-030X1333-48752013-10-0166323324410.4154/GC.2013.19459Development of framboidal pyrite in the Upper Permian marly limestone of the NE-Hungarian Darnó HillGabriella Kiss0Federica Zaccarini1Department of Mineralogy, Eötvös Loránd UniversityDepartment of Applied Geosciences and Geophysics, University of Leoben<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; The NE Hungarian Darn&oacute; Hill has a complex geology; it is built up by an accr&eacute;tionary m&eacute;lange complex, which contains Permian, Triassic and Jurassic sedimentary and magmatic blocks too. The succession can be well correlated with the NW Dinarides, and evidences of the different evolutionary stages of the Neotethyan Ocean (rifting, marginal basin opening, closure) were described too.</p><p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Several ore indications are known from this area, but their genesis was by far not well reconstructed, mostly because of the complexity of the geological background. The present study deals with one of these indications found in deep drillings. A framboidal pyrite bearing Permian-Triassic marly limestone series was investigated, which was described earlier as a possible analogy of the Polish-German copper shales (<em>Kupferschiefer</em>).</p><p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Based on detailed microscopic, EPMA and whole rock geochemical analyses, it was found, that besides the framboidal pyrite, euhedral pyrite overgrowths (both contain high amount of Au), disseminated euhedral and anhedral pyrite (which do not form framboids or overgrowths), anhedral chalcopyrite, galena and sphalerite were also found, causing a slightly enriched total metal content of 100-200 ppm. The minerals were formed under reducing, anoxic marine conditions, in more steps; after the synsedimentary processes, sulphides formed during early diagenetic/hydrothermal processes too. The found characteristics are typical to the weakly mineralized type of the <em>Kupferschiefer</em>.</p>http://www.geologia-croatica.hr/ojs/index.php/GC/article/view/617Weakly mineralized KupferschieferPermian-Triassic sedimentsframboidal pyrite
spellingShingle Gabriella Kiss
Federica Zaccarini
Development of framboidal pyrite in the Upper Permian marly limestone of the NE-Hungarian Darnó Hill
Geologia Croatica
Weakly mineralized Kupferschiefer
Permian-Triassic sediments
framboidal pyrite
title Development of framboidal pyrite in the Upper Permian marly limestone of the NE-Hungarian Darnó Hill
title_full Development of framboidal pyrite in the Upper Permian marly limestone of the NE-Hungarian Darnó Hill
title_fullStr Development of framboidal pyrite in the Upper Permian marly limestone of the NE-Hungarian Darnó Hill
title_full_unstemmed Development of framboidal pyrite in the Upper Permian marly limestone of the NE-Hungarian Darnó Hill
title_short Development of framboidal pyrite in the Upper Permian marly limestone of the NE-Hungarian Darnó Hill
title_sort development of framboidal pyrite in the upper permian marly limestone of the ne hungarian darno hill
topic Weakly mineralized Kupferschiefer
Permian-Triassic sediments
framboidal pyrite
url http://www.geologia-croatica.hr/ojs/index.php/GC/article/view/617
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