Advanced argillic minerals, as defined, include alunite and anhydrite, aluminosilicates (kaolinite, halloysite, dickite, pyrophyllite, andalusite, zunyite, and topaz), and diaspore. One or more of these minerals form in five distinctly different geologic environments of hydrolytic alteration, with pH 4–5 to <1, most at depths <500 m. (1) Where an intrusion-related hydrothermal system, typical of that associated with porphyry Cu ± Au deposits, evolves to white-mica stability, continued ascent and cooling of the white-mica–stable liquid results in pyrophyllite (± diaspore) becoming stable near the base of the lithocap. (2) A well-understood hypogene environment of formation is vapor condensation near volcanic vents, where magmatic SO₂ and HCl condense into local groundwater to produce H₂SO₄ and HCl-rich solutions with a pH of 1–1.5. Close to isochemical dissolution of the host rock occurs because of the high solubility of Al and Fe hydroxides at pH <2, except for the SiO₂ component, which remains as a siliceous residue because of the relatively low solubility of SiO₂. This residual quartz, commonly with a vuggy texture, is largely barren of metals because of the low metal content in high-temperature but low-pressure volcanic vapor. Rock dissolution causes the pH of the acidic solution to increase, such that alunite and kaolinite (or dickite or pyrophyllite at higher temperatures) become stable, forming a halo to the residual quartz. This initially barren residual quartz, which forms a lithocap horizon where permeable lithologic units are intersected by the feeder structure, may become mineralized if a subsequent white-mica–stable liquid ascends to this level and precipitates copper and gold. (3) Boiling of a hydrothermal liquid generates vapor with CO₂ and H₂S. Where the vapor condenses above the water table, atmospheric O₂ in the vadose (unsaturated) zone causes oxidation of H₂S to sulfuric acid, forming a steam-heated acid-sulfate solution with pH of 2–3. In this environment, kaolinite and alunite form in horizons above the water table at <100°C. Silica derived within the vadose zone will precipitate as amorphous silica at the water table, as the condensate follows the hydraulic gradient, causing opal replacement above and at the aquifer. (4) By contrast, where condensation of this vapor occurs below the water table, the CO₂ in solution forms carbonic acid (H₂CO₃), leading to a pH of 4–5. This marginal carapace of condensate, with temperatures up to 150°–170°C, commonly acts as a diluent of the ascending parental NaCl liquid. This steam-heated liquid forms intermediate argillic alteration of clays, kaolinite, and Fe-Mn carbonates; this kaolinite, which can be present at depths of several hundreds of meters, can potentially be mistaken as having been caused by a steam-heated acid-sulfate or supergene overprint. (5) The final setting is supergene, caused by posthydrothermal weathering and oxidation of mainly pyrite, locally creating pH <1 liquid because of high concentrations of H₂SO₄ within the vadose zone and forming kaolinite, alunite, and Fe oxyhydroxides.This genetic framework of formation environments of advanced (and intermediate) argillic alteration provides the basis to interpret alteration mineralogy, in combination with alteration textures and morphology plus zonation, including the overprint of one alteration style on another. This framework can be used to help focus exploration for and assessment of hydrothermal ore deposits, including epithermal, porphyry, and volcanic-hosted massive sulfide.

中文翻译：

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高级泥质矿物多种形成环境的勘探启示

根据定义，高级泥质矿物包括明矾石和硬石膏、硅铝酸盐（高岭石、埃洛石、地开石、叶蜡石、红柱石、zunyite 和黄玉）和水铝石。这些矿物中的一种或多种形成于五种截然不同的水解蚀变地质环境中，pH 值在 4-5 到 <1 之间，大部分在深度 <500 米处。(1) 与侵入相关的热液系统，典型的与斑岩铜金矿床相关的热液系统，演变为白云母稳定，白云母稳定液体的持续上升和冷却导致叶蜡石（±水铝石）变得稳定靠近岩石盖的底部。(2) 一个众所周知的低成因形成环境是火山口附近的蒸汽凝结，岩浆 SO ₂和 HCl 凝结成当地地下水产生 H ₂富含SO _{4和 HCl 的溶液，pH 值为 1–1.5。}由于 Al 和 Fe 氢氧化物在 pH <2 时的高溶解度，因此母岩接近等化学溶解发生，除了 SiO _{2组分，由于 SiO 2 的溶解度相对较低，SiO 2}组分保持为硅质残余物. 由于高温低压火山蒸汽中的金属含量低，这种残留的石英通常具有孔洞结构，基本上不含金属。岩石溶解导致酸性溶液的 pH 值增加，从而使明矾石和高岭石（或在较高温度下的地开石或叶蜡石）变得稳定，从而对残留的石英形成光晕。如果随后的白云母稳定液体上升到该水平并沉淀铜和金，这种最初贫瘠的残余石英会形成岩盖层，其中可渗透的岩性单元与馈线结构相交。(3) 热液沸腾产生含有 CO ₂和 H ₂ S 的蒸汽。当蒸汽在地下水位以上冷凝时，大气中的 O _{2在渗气（不饱和）区域中，H 2} S 被氧化为硫酸，形成一种蒸汽加热的酸性硫酸盐溶液，pH 值为 2-3。在这种环境中，高岭石和明矾石在低于 100°C 的地下水位上方形成。在渗流带中衍生的二氧化硅将在地下水位以无定形二氧化硅的形式沉淀，因为冷凝物遵循水力梯度，导致蛋白石在含水层上方和含水层处发生置换。(4) 相反，当这种蒸汽在地下水位以下发生冷凝时，溶液中的 CO ₂形成碳酸 (H ₂ CO ₃)，导致 pH 值为 4-5。这种冷凝液的边缘外壳，温度高达 150°–170°C，通常用作上升的亲代 NaCl 液体的稀释剂。这种蒸汽加热的液体形成粘土、高岭石和铁锰碳酸盐的中间泥质蚀变；这种高岭石可能存在于数百米深处，可能会被误认为是由蒸汽加热的酸性硫酸盐或表生叠印造成的。(5) 终凝为表生，由热液后风化和主要黄铁矿氧化造成，由于H ₂ SO _{4浓度高，局部形成pH <1液体}在包气带内形成高岭石、明矾石和氢氧化铁。这种高级（和中间）泥质蚀变形成环境的遗传框架为解释蚀变矿物学提供了基础，结合蚀变纹理和形态加分带，包括叠印一种改变风格的另一种风格。该框架可用于帮助集中勘探和评估热液矿床，包括浅成热液、斑岩和火山岩块状硫化物。