Alteration - Porphyries
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ALTERATION - PORPHYRIES Occurs with minor mineralization in the deeper Potassic parts of some porphyry systems, and is a host to mineralization in porphyry deposits associated with alkaline intrusions © Copyright Spectral International Inc. Sodic, sodic-calcic Propylitic Potassic alteration shows Actinolite, biotite, phlogopite, epidote, iron- chlorite, Mg-chlorite, muscovite, quartz, anhydrite, magnetite. Albite, actinolite, diopside, quartz, Fe-chlorite, Mg-chlorite, epidote, actinolite, magnetite, titanite, chlorite, epidote, calcite, illite, montmorillonite, albite, pyrite. scapolite Intermediate argillic alteration generally This is an intense alteration phase, often in the Copyright Spectral International Inc.© forms a structurally controlled to upper part of porphyry systems. It can also form envelopes around pyrite-rich veins that Phyllic alteration commonly forms a widespread overprint on other types of cross cut other alteration types. peripheral halo around the core of alteration in many porphyry systems porphyry deposits. It may overprint earlier potassic alteration and may host substantial mineralization ADVANCED ARGILLIC Phyllic INTERMEDIATE ARGILLIC The minerals associated with this type The detectable minerals include are higher temperature and include illite, muscovite, dickite, kaolinite, pyrophyllite, quartz, andalusite, Fe-chlorite, Mg-chlorite, epidote, diaspore, corundum, alunite, topaz, montmorillonite, calcite, and pyrite tourmaline, dumortierite, pyrite, and hematite EXOTIC COPPER www.e-sga.org/ CU PHOSPHATES Cu Cu CARBONATES CHLORIDES Azurite, malachite, aurichalcite, rosasite Atacamite, connellite, and cumengite © Copyright Spectral International Inc. Cu-ARSENATES EXOTIC COPPER Cu-SILICATES Cu-SULFATES bayldonite, antlerite, chenevixite chrysocolla dioptase brochantite, conichalcite chalcanthite clinoclase papagoite shattuckite cyanotrichite olivenite kroehnite, spangolite © Copyright Spectral International Inc. © Copyright Spectral International Inc. LEACH CAP MINERALS .