斯里兰卡Seruwila铜磁铁矿磷灰石矿床中的金矿

Nishika Samarakoon , Sanjeewa P.K. Malaviarachchi , Atula Senaratne , Athula Wijayasinghe
{"title":"斯里兰卡Seruwila铜磁铁矿磷灰石矿床中的金矿","authors":"Nishika Samarakoon ,&nbsp;Sanjeewa P.K. Malaviarachchi ,&nbsp;Atula Senaratne ,&nbsp;Athula Wijayasinghe","doi":"10.1016/j.oreoa.2021.100014","DOIUrl":null,"url":null,"abstract":"<div><p>This study presents petrology and evidence for possible gold occurrences in Seruwila copper–iron oxide–apatite (IOA) deposit, hosted in an ultramafic intrusion which is located at the boundary between the Highland and Vijayan complexes, within the intermediate-granitic basement in north-eastern Sri Lanka. The study is complemented with petrological observations and XRD and SEM analysis, respectively, to investigate the petrology/subsurface geology of the deposit and identify possible gold occurrences in the deposit. The ore-bearing rocks are mainly composed of magnetite and apatite in various proportions, hosted in an ultramafic intrusion with cumulate features within the granitic-intermediate basement. The secondary veins contain magnetite, chalcopyrite, pyrrhotite, and pyrite together with apatite and scapolite, tremolite, diopside, and minor actinolite and calcite, serpentinite, anhydrite, or gypsum. The clinopyroxene euhedral crystals show cumulus textures including grain triple junctions and large dihedral angles (∼120°), showing magmatic origin. Texturally two types of amphiboles are identified as coarse-grained (0.5–1 mm), pale green euhedral amphibole that is free of inclusions, and fine-grained (&lt;0.1 mm) and brownish, occurring as anhedral inclusions in clinopyroxene. The deposit contains varying amounts of sulfides in which pyrite is the potential gold carrier in magmatic–hydrothermal processes. By the results of XRD analysis, it is evident that the presence of Au (111), Au (200), Au (220) and Au (311), although with low count values (50–500), probably due to the low concentration of gold. Therefore, particularly in the samples with veins or veinlets, gold was inferred to be present in pyrite/chalcopyrite as invisible structurally-bonded gold and/or gold nanoparticles. Hence, the results of this study, although at non-ore grade, veinlets of gold-bearing pyrite/chalcopyrite may serve as a promising target for gold occurrence, being a potential site of gold-mineralization in the context of the East-Gondwana.</p></div>","PeriodicalId":100993,"journal":{"name":"Ore and Energy Resource Geology","volume":"8 ","pages":"Article 100014"},"PeriodicalIF":0.0000,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.oreoa.2021.100014","citationCount":"0","resultStr":"{\"title\":\"Gold occurrences in copper-magnetite-apatite deposit at Seruwila, Sri Lanka\",\"authors\":\"Nishika Samarakoon ,&nbsp;Sanjeewa P.K. Malaviarachchi ,&nbsp;Atula Senaratne ,&nbsp;Athula Wijayasinghe\",\"doi\":\"10.1016/j.oreoa.2021.100014\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>This study presents petrology and evidence for possible gold occurrences in Seruwila copper–iron oxide–apatite (IOA) deposit, hosted in an ultramafic intrusion which is located at the boundary between the Highland and Vijayan complexes, within the intermediate-granitic basement in north-eastern Sri Lanka. The study is complemented with petrological observations and XRD and SEM analysis, respectively, to investigate the petrology/subsurface geology of the deposit and identify possible gold occurrences in the deposit. The ore-bearing rocks are mainly composed of magnetite and apatite in various proportions, hosted in an ultramafic intrusion with cumulate features within the granitic-intermediate basement. The secondary veins contain magnetite, chalcopyrite, pyrrhotite, and pyrite together with apatite and scapolite, tremolite, diopside, and minor actinolite and calcite, serpentinite, anhydrite, or gypsum. The clinopyroxene euhedral crystals show cumulus textures including grain triple junctions and large dihedral angles (∼120°), showing magmatic origin. Texturally two types of amphiboles are identified as coarse-grained (0.5–1 mm), pale green euhedral amphibole that is free of inclusions, and fine-grained (&lt;0.1 mm) and brownish, occurring as anhedral inclusions in clinopyroxene. The deposit contains varying amounts of sulfides in which pyrite is the potential gold carrier in magmatic–hydrothermal processes. By the results of XRD analysis, it is evident that the presence of Au (111), Au (200), Au (220) and Au (311), although with low count values (50–500), probably due to the low concentration of gold. Therefore, particularly in the samples with veins or veinlets, gold was inferred to be present in pyrite/chalcopyrite as invisible structurally-bonded gold and/or gold nanoparticles. Hence, the results of this study, although at non-ore grade, veinlets of gold-bearing pyrite/chalcopyrite may serve as a promising target for gold occurrence, being a potential site of gold-mineralization in the context of the East-Gondwana.</p></div>\",\"PeriodicalId\":100993,\"journal\":{\"name\":\"Ore and Energy Resource Geology\",\"volume\":\"8 \",\"pages\":\"Article 100014\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2021-09-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1016/j.oreoa.2021.100014\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Ore and Energy Resource Geology\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2666261221000031\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Ore and Energy Resource Geology","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2666261221000031","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0

摘要

本文研究了斯里兰卡东北部中花岗岩基底内的Seruwila氧化铁铜磷灰石(IOA)矿床的岩石学和可能的金矿床证据,该矿床位于高地和Vijayan杂岩之间的超镁铁质侵入体中。结合岩石学观测、x射线衍射(XRD)和扫描电镜(SEM)分析,对矿床的岩石学/地下地质进行了研究,并确定了矿床可能的金赋存点。含矿岩主要由不同比例的磁铁矿和磷灰石组成,赋存于花岗岩-中间基底内具有堆积特征的超镁铁质侵入体中。次生矿脉含磁铁矿、黄铜矿、磁黄铁矿、黄铁矿、磷灰石、橄榄石、透辉石、少量放光石、方解石、蛇纹石、硬石膏或石膏。斜辉石自面体晶体呈积云结构,包括颗粒三重结和大二面角(~ 120°),显示岩浆成因。两种类型的角闪石在结构上被识别为粗粒角闪石(0.5-1 mm),淡绿色的自形角闪石,不含包裹体;细粒角闪石(<0.1 mm),呈褐色,在斜辉石中出现为斜面体包裹体。矿床含不同数量的硫化物,其中黄铁矿是岩浆-热液作用中潜在的金载体。XRD分析结果表明,虽然Au(111)、Au(200)、Au(220)和Au(311)的计数值较低(50-500),但可能是由于金的浓度较低所致。因此,特别是在有脉或细脉的样品中,推断金以不可见的结构键合金和/或金纳米颗粒的形式存在于黄铁矿/黄铜矿中。因此,本研究结果表明,虽然在非矿石品位,含金黄铁矿/黄铜矿细脉可能是一个有希望的金赋存目标,是东冈瓦纳地区金矿化的潜在场所。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Gold occurrences in copper-magnetite-apatite deposit at Seruwila, Sri Lanka

This study presents petrology and evidence for possible gold occurrences in Seruwila copper–iron oxide–apatite (IOA) deposit, hosted in an ultramafic intrusion which is located at the boundary between the Highland and Vijayan complexes, within the intermediate-granitic basement in north-eastern Sri Lanka. The study is complemented with petrological observations and XRD and SEM analysis, respectively, to investigate the petrology/subsurface geology of the deposit and identify possible gold occurrences in the deposit. The ore-bearing rocks are mainly composed of magnetite and apatite in various proportions, hosted in an ultramafic intrusion with cumulate features within the granitic-intermediate basement. The secondary veins contain magnetite, chalcopyrite, pyrrhotite, and pyrite together with apatite and scapolite, tremolite, diopside, and minor actinolite and calcite, serpentinite, anhydrite, or gypsum. The clinopyroxene euhedral crystals show cumulus textures including grain triple junctions and large dihedral angles (∼120°), showing magmatic origin. Texturally two types of amphiboles are identified as coarse-grained (0.5–1 mm), pale green euhedral amphibole that is free of inclusions, and fine-grained (<0.1 mm) and brownish, occurring as anhedral inclusions in clinopyroxene. The deposit contains varying amounts of sulfides in which pyrite is the potential gold carrier in magmatic–hydrothermal processes. By the results of XRD analysis, it is evident that the presence of Au (111), Au (200), Au (220) and Au (311), although with low count values (50–500), probably due to the low concentration of gold. Therefore, particularly in the samples with veins or veinlets, gold was inferred to be present in pyrite/chalcopyrite as invisible structurally-bonded gold and/or gold nanoparticles. Hence, the results of this study, although at non-ore grade, veinlets of gold-bearing pyrite/chalcopyrite may serve as a promising target for gold occurrence, being a potential site of gold-mineralization in the context of the East-Gondwana.

求助全文
通过发布文献求助,成功后即可免费获取论文全文。 去求助
来源期刊
自引率
0.00%
发文量
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信