Extreme enrichment of Arsenic and Antimony during alteration of serpentinised peridotites to form listvenite-like dolomite-quartz rocks and Ni-Cr-rich jasper and quartzites in the Highland Border Complex of Scotland
{"title":"Extreme enrichment of Arsenic and Antimony during alteration of serpentinised peridotites to form listvenite-like dolomite-quartz rocks and Ni-Cr-rich jasper and quartzites in the Highland Border Complex of Scotland","authors":"H. Austrheim, Torgeir B. Andresen","doi":"10.1144/jgs2023-054","DOIUrl":null,"url":null,"abstract":"\n Alteration of serpentinised peridotites of Highland Border Complex in Scotland took place in two steps. Listvenite-like dolomite-quartz rocks formed by addition of CaO, Sr and CO\n 2\n at constant MgO and SiO\n 2\n involving a mass increase of ca. 140 %. Stage-two involved the dissolution of dolomite evinced by the abundant pores and rhombohedral-shaped grains of quartz to form Cr- and Ni-rich jasper and quartzites. Formation of the jasper-quartzites involve a mass reduction of ca. 80%. The listvenite-like and jasper-quartzite rocks have enrichment in the fluid mobile elements Ba, Sr, Cs, As and Sb. The As is present in the Aluminium-Phosphate-Sulphate group of minerals formed during alteration of Cr-spinel. Cr-spinel also alters to porous hematite and ferrihydrite with patches containing up to 5.5 wt% As\n 2\n O\n 3\n . Enrichment of As, related to alteration of chromite, is previously unknown from natural rocks, but strongly resembles efficient methods used for remediation of this toxic element. Formation of quartzite and jasper from peridotite and their common presence as pebbles both in the Devonian Old Red conglomerates, in the Highland Border Complex and in Devonian Basins in the Scandinavian Caledonides, highlights their importance and potential for provenance- and tectono-stratigraphic correlations.\n \n \n Thematic collection:\n This article is part of the Ophiolites, melanges and blueschists collection available at:\n https://www.lyellcollection.org/topic/collections/ophiolites-melanges-and-blueschists\n \n \n Supplementary material:\n https://doi.org/10.6084/m9.figshare.c.6764598\n","PeriodicalId":17320,"journal":{"name":"Journal of the Geological Society","volume":" ","pages":""},"PeriodicalIF":2.6000,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the Geological Society","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1144/jgs2023-054","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Alteration of serpentinised peridotites of Highland Border Complex in Scotland took place in two steps. Listvenite-like dolomite-quartz rocks formed by addition of CaO, Sr and CO
2
at constant MgO and SiO
2
involving a mass increase of ca. 140 %. Stage-two involved the dissolution of dolomite evinced by the abundant pores and rhombohedral-shaped grains of quartz to form Cr- and Ni-rich jasper and quartzites. Formation of the jasper-quartzites involve a mass reduction of ca. 80%. The listvenite-like and jasper-quartzite rocks have enrichment in the fluid mobile elements Ba, Sr, Cs, As and Sb. The As is present in the Aluminium-Phosphate-Sulphate group of minerals formed during alteration of Cr-spinel. Cr-spinel also alters to porous hematite and ferrihydrite with patches containing up to 5.5 wt% As
2
O
3
. Enrichment of As, related to alteration of chromite, is previously unknown from natural rocks, but strongly resembles efficient methods used for remediation of this toxic element. Formation of quartzite and jasper from peridotite and their common presence as pebbles both in the Devonian Old Red conglomerates, in the Highland Border Complex and in Devonian Basins in the Scandinavian Caledonides, highlights their importance and potential for provenance- and tectono-stratigraphic correlations.
Thematic collection:
This article is part of the Ophiolites, melanges and blueschists collection available at:
https://www.lyellcollection.org/topic/collections/ophiolites-melanges-and-blueschists
Supplementary material:
https://doi.org/10.6084/m9.figshare.c.6764598
期刊介绍:
Journal of the Geological Society (JGS) is owned and published by the Geological Society of London.
JGS publishes topical, high-quality recent research across the full range of Earth Sciences. Papers are interdisciplinary in nature and emphasize the development of an understanding of fundamental geological processes. Broad interest articles that refer to regional studies, but which extend beyond their geographical context are also welcomed.
Each year JGS presents the ‘JGS Early Career Award'' for papers published in the journal, which rewards the writing of well-written, exciting papers from early career geologists.
The journal publishes research and invited review articles, discussion papers and thematic sets.