The Avalon Zone hosts well-preserved examples of high- and low-sulfidation epithermal Au-Ag mineralization and associated phyllosilicate alteration. Using examples from the Hope Brook and Hickey's Pond high-sulfidation systems (HSS) and the Heritage low-sulfidation system (LSS), this study presents new data on the mineralogical and chemical characterization of phyllosilicates associated with epithermal Au-Ag deposits. Electron probe microanalysis and X-ray diffraction studies revealed that the HSS examples contain Fe muscovite ((K_0.62–0.79Na_0.10–0.37Ca_0.00–0.01)Al_1.31–1.72(Mg_0.01–0.08Fe_0.05–0.19)(Al_1.00–1.24Si_2.76–3.00O₁₀)(OH)₂), paragonite ((K_0.05–0.30Na_0.78–1.02Ca_0.00–0.01)Al_1.66–1.84(Mg_0.00–0.01Fe_0.02–0.04)(Al_1.01–1.11Si_2.89–2.99O₁₀)(OH)₂), Al clinochlore ((Mg_2.42–2.65Fe_1.62–1.78)(Si_2.57–2.69Al_1.31–1.43O₁₀)(OH)₈), pyrophyllite, kaolin minerals, illite-smectite (I-Sme) and chlorite-smectite (C-Sme). Conversely, the LSS examples contain Fe-Mg muscovite ((K_0.44–0.76Na_0.00–0.02Ca_0.00–0.01)Al_1.55–1.82(Mg_0.17–0.31Fe_0.05–0.12)(Al_0.55–0.71Si_3.29–3.45O₁₀)(OH)₂), Al clinochlore ((Mg_2.17–2.56Fe_1.59–2.01)(Si_2.71–2.92Al_1.08–1.29O₁₀)(OH)₈), and I-Sme and C-Sme intermediates. Chlorite geothermometry indicated that HSS and LSS assemblages crystallized at average temperatures of 261 °C and 145 °C, respectively. Mica and chlorite from HSS and LSS are defined by Tschermak substitution and high-temperature polytypism (2M₁ and IIb, respectively). In the HSS examples, one or more pulses of hot, acidic fluid reacted with host rocks generating an envelope of advanced argillic alteration (Fe-Ms, Kln, Pg, Prl) around a vuggy silica core. This is bounded by a zone of argillic alteration (Fe-Ms, Kln), with sericitic/chloritic alterations (Fe-Ms, Al-Clc) developed in distal parts of the systems. In the LSS, near-neutral hydrothermal fluids led to the formation of broad phyllic/chloritic zones (Fe-Mg Ms and Al-Clc). A low temperature overprint with 1M mica, Ib clinochlore ((Mg_2.48–2.74Fe_1.58–1.73)(Si_3.05–3.15Al_0.85–0.95O₁₀)(OH)₈), kaolinite and Sme-poor I-Sme and C-Sme is attributed to late waning stage hydrothermal activity and/or weathering. A close paragenetic link was established between Fe-Mg muscovite and Ag mineralization at Heritage, as well as between Fe-Mg muscovite and bladed calcite, suggesting boiling as the precipitation mechanism. The present study provides guidance on how phyllosilicate assemblages have the potential to discern HSS versus LSS mineralization during early prospection in terranes with limited exposure, and to contribute to the reconstruction of their hydrothermal record.

阿瓦隆地区保存着保存完好的高硫和低硫超热金-银矿化以及相关的页硅酸盐蚀变的例子。利用Hope Brook和Hickey的Pond高硫化系统（HSS）和Heritage低硫化系统（LSS）的示例，本研究提供了与超热Au-Ag沉积有关的层状硅酸盐的矿物学和化学特征的新数据。电子探针显微分析和X射线衍射研究显示，HSS实施例含有的Fe白云母（（K _{0.62 - 0.79}钠_{0.10 - 0.37}的Ca _{0.00 - 0.01}）的Al _{1.31 - 1.72}（镁_{0.01 - 0.08}Fe _{0.05 – 0.19}）（Al _{1.00 – 1.24} Si _{2.76 – 3.00} O ₁₀（OH）₂），方钠石（（K _{0.05 – 0.30} Na _{0.78 – 1.02} Ca _{0.00 – 0.01}）Al _{1.66 – 1.84}（Mg _{0.00 – 0.01} Fe _{0.02 – 0.04}）（Al _{1.01 – 1.11} Si _{2.89 – 2.99} O ₁₀）（OH）₂），氯化铝（（Mg _{2.42 – 2.65} Fe _{1.62 – 1.78}）（Si _{2.57 – 2.69} Al _{1.31 – 1.43} O ₁₀）（OH）₈），叶蜡石，高岭土矿物，伊利石-蒙脱石（I-Sme）和绿泥石-蒙脱石（C-Sme）。相反地，LSS示例包含铁-镁白云母（（K _{0.44 - 0.76}钠_{0.00 - 0.02}的Ca _{0.00 - 0.01}）的Al _{1.55 - 1.82}（镁_{0.17 - 0.31}铁_{0.05 - 0.12}）（Al _{0.55 – 0.71} Si _{3.29 – 3.45} O ₁₀）（OH）₂），氯化铝（（Mg _{2.17 – 2.56} Fe _{1.59 – 2.01}）（Si _{2.71 – 2.92} Al _{1.08 – 1.29} O ₁₀）（OH）₈），以及I-Sme和C-Sme中间体。亚氯酸盐地热测定表明，HSS和LSS组合分别在平均温度261°C和145°C时结晶。来自HSS和LSS的云母和亚氯酸盐通过Tschermak取代和高温多型性（2M ₁和IIb）。在HSS实例中，一个或多个热的酸性流体脉冲与基质岩石反应，在蓬松的二氧化硅岩心周围产生了先进的阿尔吉尔蚀变（Fe-Ms，Kln，Pg，Prl）包膜。这是由一个在系统的远侧部分形成的浆液蚀变区（Fe-Ms，Kln）界定的，其中有浆液性/氯性蚀变区（Fe-Ms，Al-Clc）。在LSS中，接近中性的热液导致形成广阔的叶绿体区域（Fe-Mg Ms和Al-Clc）。带有1M云母，氯丁酸Ib（（Mg _{2.48 – 2.74} Fe _{1.58 – 1.73}）（Si _{3.05 – 3.15} Al _{0.85– 0.95} O ₁₀）（OH）₈），高岭石和贫Sme-Ime和C-Sme归因于后期减弱的热液活动和/或风化作用。铁-镁白云母与遗产遗址的银矿化之间以及铁-镁白云母与片状方解石之间建立了密切的共生联系，表明沸腾是沉淀的机制。本研究提供了关于层状硅酸盐组合物如何在潜在的有限暴露地层的早期勘探期间识别HSS与LSS矿化的潜力以及为重建其水热记录做出贡献的指导。