The lone granodiorite-hosted gold deposit at Dona sector of Jonnagiri, eastern Dharwar craton, India, contains typical shear-hosted and vein-hosted alteration zones. Pyrite is the dominant sulfide mineral in these alteration zones. Texturally three varieties of pyrites were identified in these alteration zones: (1) early pyrite-I is coarse to medium grained and subhedral shaped and contains near margin-parallel silicate inclusions, (2) main (ore)-stage pyrite-II overgrows early pyrite-I and also occurs as discrete grains invariably associated with visible gold, and (3) late-stage pyrite-III is anhedral and coarse grained and contains randomly oriented inclusions of silicates, sulfides, and native gold grains.Electron microprobe analysis, coupled with X-ray element mapping and laser ablation-inductively coupled plasma-mass spectrometry, reveals that most early pyrites (pyrite-I) have higher concentrations of As and Au in both the zones. The shear-hosted main-stage pyrite-II can be divided into Ni-rich (median 211 ppm) pyrite-IIa and Co-rich (median 274 ppm) pyrite-IIb, respectively. While invisible gold content is higher in vein-hosted late-stage pyrite (pyrite-IIIa; ≤287 ppm) when compared to shear-hosted pyrites, native visible gold is associated with only vein-hosted main- and late-stage pyrites (pyrite-II and IIIa). Arsenic, Ni, Au, Se, Mo, and Te concentrations decrease from pyrite-I to pyrite-III, reflecting remobilization of trace elements during subsequent dissolution-reprecipitation of early formed pyrites. The oscillatory zoning of As, Co, and Ni and slight increase in Bi, Te, Se, Au, and Ag in pyrite-II and pyrite-IIIa represent pressure fluctuations and repeated local fluid phase separation in the ore-forming environment. A positive correlation of Au with Pb, Sb, Bi, and Te confirms the presence of nanoinclusions of mineral phases such as nagyagite, Pb-Sb-Bi tellurides, Au-Ag tellurides, tellurosulfides, and sulfosalts within pyrites, particularly in the vein-hosted zone.Based on several lines of evidence, the following paragenetic sequence is proposed for pyrite formation at Dona, Jonnagiri. Rapid crystallization of early (porous) pyrite-I was followed by its dissolution during ~E-W–trending Sh₁ shearing. Crystallization of main-stage pyrite-II and the late-stage pyrite-IIIa is the product of dissolution-reprecipitation of early pyrite during ~N-S–trending Sh₂ shearing. Changing fluid compositions caused by episodic fault-valve actions and associated boiling resulted in dissolution-reprecipitation of early formed pyrites and remobilization of trace elements. This further resulted in precipitation of the bulk of gold within the inner vein-hosted zone during the later Sh₂ shearing event. At the culmination of shearing, late-stage pyrite-IIIb precipitation occurs with very low concentrations of all trace elements, including gold.

中文翻译：

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印度东部达瓦尔克拉顿Jonnagiri的花岗闪长岩型金矿床的硫铁矿质地和微量元素组成：对金矿化过程的影响

印度东部Dharwar克拉通Jonnagiri的Dona区段中唯一的由花岗闪长岩类为主的金矿床，包含典型的剪切带和脉动带蚀变带。黄铁矿是这些蚀变带中主要的硫化物矿物。从结构上看，在这些蚀变带中发现了三个黄铁矿变种：（1）早期的黄铁矿-I为粗粒至中粒状和近半角形，并包含近乎边缘平行的硅酸盐夹杂物；（2）早期的主要（矿石）阶段黄铁矿-II过度生长黄铁矿-I，也以离散的晶粒形式存在，总是与可见的金相关联;（3）后期的黄铁矿-III是无规和粗大晶粒，并且包含随机排列的硅酸盐，硫化物和天然金晶粒的夹杂物。借助X射线元素映射和激光烧蚀-电感耦合等离子体质谱法，揭示大多数早期黄铁矿（黄铁矿-I）在两个区域中的砷和金的浓度都较高。剪切承载的主要阶段黄铁矿-II可以分别分为富镍（中值211 ppm）黄铁矿-IIa和富钴（中值274 ppm）黄铁矿-IIb。尽管与剪切型黄铁矿相比，脉状黄铁矿（硫铁矿-IIIa；≤287ppm）中的可见金含量更高，但天然可见金仅与脉状的主黄铁矿和后期黄铁矿（黄铁矿）相关。 -II和IIIa）。砷，镍，金，硒，钼和碲的浓度从黄铁矿I降低到黄铁矿III，这反映了早期形成的黄铁矿在随后的溶解-再沉淀过程中微量元素的迁移。As，Co和Ni的振荡区带以及Bi，Te，Se，Au，黄铁矿II和黄铁矿IIIa中的Ag代表压力波动和成矿环境中反复的局部液相分离。Au与Pb，Sb，Bi和Te呈正相关，这证实了黄铁矿（特别是在脉管中）存在矿物相的纳米夹杂物，例如菱镁矿，Pb-Sb-Bi碲化物，Au-Ag碲化物，碲硫化物和亚硫酸盐。根据几条证据，提出以下在Jonnagiri的Dona的黄铁矿形成的共生序列。早期（多孔）黄铁矿-I的快速结晶，随后在〜EW趋势中溶解。Sh 硫铁矿中的硫铝铁矿和硫盐，特别是在脉藏区。根据几条证据，提出以下在金纳吉里（Donna）的黄铁矿形成黄铁矿的共生序列。早期（多孔）黄铁矿-I的快速结晶，随后在〜EW趋势中溶解（Sh）硫铁矿中的硫铝铁矿和硫盐，特别是在脉藏区。根据几条证据，提出以下在金纳吉里多纳形成黄铁矿的亚同生代序列。早期（多孔）黄铁矿-I的快速结晶，随后在〜EW趋势中溶解。Sh₁剪。主要阶段的黄铁矿II和后期的黄铁矿IIIa的结晶是〜NS趋势Sh ₂剪切过程中早期黄铁矿的溶解-再沉淀产物。由偶发断层阀作用和相关沸腾引起的流体成分变化导致早期形成的黄铁矿的溶解-再沉淀和微量元素的迁移。在随后的Sh ₂剪切事件中，这进一步导致大量的金沉淀在内脉主控区内。在剪切作用达到高潮时，发生后期的黄铁矿-IIIb沉淀，所有微量元素（包括金）的浓度都非常低。