Pdf ree distribution and behaviour during hydrothermal alteration in three deposits is presented. Pdf documents opened from your browser may not display or print as intended. Mapping argillic and advanced argillic alteration in volcanic rocks. Over 30 occurrences of aaa are known in bulgaria velinov et al, 2003, some of them associated with porphyry copper and epithermal deposits. The deeper part of the ore body, where potassic alteration dominates, is nearly arsenicfree, whereas the upper part of the copper ore body is arsenicbearing. Argillic alteration is hydrothermal alteration of wall rock which introduces clay minerals. The simplest means of producing these lower ph, lower temperature fluids is to interact. Gsa 2000b unusual advanced argillic alteration of the sw.
Pat, 2012, hydrothermal alteration in volcanogenic massive sulfide occurrence model. In advanced argillic alteration mree and hree are strongly depleted while lree are immobile. Hydrothermal alteration institute for mining geology. Highly weathered soil orders such as ultisols and oxisols cover nearly 16%. Mapping argillic and advanced argillic alteration in volcanic. Role of potassic alteration for porphyry cu mineralization. Zunyite, along with various amounts of quartz, alunite, aluminum phosphatesulfate minerals aps, diaspore, kaolinite, and minor pyrophyllite, are the main minerals in the advanced argillic alteration.
These show up as the pink spots on the image on the right. The earliest signs of argillic alteration include the bleaching out of feldspars. Argillic and advanced argillic alteration are shallow types of alteration encountrered in a variety of different types of hydrothermal systems. The grasberg cuau porphyry deposit in irian jaya, indonesia, is one of the largest cuau deposits in the world, and manifests a range of alteration types that extend from potassic to advanced argillic. Pdf environments of advanced argillic alteration i. May 24, 2015 argillic is often used for texturally destructive alteration that has a similar clayrich mineralogy, and which occurs in and around structures in the upper parts of porphyry systems. Pla 1997, modeling a slope characteristic of the western andes of venezuela, found that simple reforestation of a degraded pasture was not sufficient to prevent landslideshydraulic conductivity was so low in the argillic horizon of ultisols that drainage ditches were required to prevent saturationinduced translational failure.
The spectral angle mapper algorithm was used in this study to map three advanced argillic alteration minerals alunite, kaolinite, and dickite in a known alteration zone in the peruvian andes. Advanced argillic alteration forms in five various 15, mainly shallow acidic environments, producing a variety of minerals that can include kaolinite, alunite and pyrophyllite. Mineralization and alteration of a modern seafloor massive. The geological setting is jurassic greywacke basement overlain by late miocene andesiticdacitic. Argillic definition of argillic by the free dictionary. Mapping argillic and advanced argillic alteration in volcanic rocks, quartzites, and quartz. This genetic framework of environments of formation of advanced argillic alteration helps to interpret alteration mineralogy plus its morphology and zonation during exploration and assessment of. These images from my earlier talk on porphyry exploration, with exploration for high sulfidation systems were looking for the same sort of alteration as with porphyries, in other words silicic, argillic and advanced argillic silicification. Advanced argillic alteration mineral assemblages precipitate from so2 and. Phyllic alteration is often closely associated with argillic alteration, which occurs at lower temperatures and dominantly affects plagioclase.
Element mobility during zeolitic and argillic alteration of. The process generally occurs at low temperatures and may occur in atmospheric conditions. Argillic alteration is representative of supergene environments where low temperature groundwater becomes acidic. Argillicadvanced argillic alteration open energy information. Argillic horizons and claysized particles an alternative interpretation of their dynamics in sola development and across catenas mostafa abdelssamie abdelkhalik ibrahim iowa state university follow this and additional works at. A quantitative approach to genetic issues of argillic and propylitic alteration zones of epithermal cupbfe deposits related to andesitic magmatism khan kandi district, nw iran. Distributions of febearing minerals, clays, micas, sulfates, and carbonates were mapped using the tetracorder spectralshape matching system.
Sericitic and advanced argillic mineral assemblages and. Alteration assemblages vary with depth and with degree of fluid interaction. Hydrothermal alteration mapping from landsat8 data, sar. Case study olduvai gorge, tanzania, chemical geology on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
Major styles of mineralization and hydrothermal alteration. More distal and downwards, advanced argillic alteration gradually evolves into phyllic assemblages dominated by quartz and sericite. Mapping argillic and advanced argillic alteration in volcanic rocks, quartzites, and quartz arenites in the western richfield 1 x 2 quadrangle, southwestern utah, using aster satellite data. Nor is there a zonation of oxygen isotopic compositions that would be predicted for intrusiondriven waterrock interactionmagmatic fluids near the intrusive centres followed progressively outwards by sup. Sericitic and advanced argillic mineral assemblages. Similar lithocaps are also recognized in the shallowly eroded southern part of the bolivian tinsilver belt, where mineralization typically is centred on felsic volcanic domes. Zones of advanced argillic alteration constituting lithocaps are commonplace in the shallow parts of porphyry copper systems. Hydrothermal alteration associated with the gic includes potassic, phyllic, and advanced argillic. Advanced argillic is a special type of alteration that. The values of the aaai at basin lake are similar to those of several highsulfidation epithermal deposits.
Dec 29, 2016 hydrothermal alteration zones can be recognized upon the spectral characteristics of main mineral assemblages. Argillic alteration is recognized in association with uranium deposits on the colorado. However, hyperion with its fine spectral bands has potential for good separability of features. Silicic and argillic alterations are confined in the immediate wall rocks of the quartz veins. Advanced argillic alteration in the deeply buried magma porphyry cumo prospect, superior, alabama. Phyllic alteration and argillic advanced argillic assemblages are derived from increasing acidic hydrothermal fluids generally of lower temperature than common for potassic and propylitic assemblages. Jul 30, 2009 read element mobility during zeolitic and argillic alteration of volcanic ash in a closedbasin lacustrine environment. Argillic alteration is representative of supergene environments where low temperature groundwater becomes. Pdf the konos hill prospect in ne greece represents a telescoped mocure au porphyry occurrence. Argillic horizons and claysized particles an alternative. Phyllic alteration typically forms in the basemetal zone of a porphyry system. The dating of alunite from an area of advanced argillic alteration at nankivel hill provides new data on the timing of hydrothermal fluid activity that links with the c. Oct 07, 2017 argillic alteration is hydrothermal alteration of wall rock which introduces clay minerals including kaolinite, smectite and illite. Mapping advanced argillic alteration at cuprite, nevada.
Argillic alteration is hydrothermal alteration citation needed of wall rock which introduces clay minerals including kaolinite, smectite and illite. Journal of taibah university for science 9 2015 155166 available online at. A wellpreserved lithocap at potosi is dominated by vuggy residual quartz and contained the. Spectral characteristics of propylitic alteration minerals as a. Download the latest version of adobe reader, free of charge. Sciencedirect hydrothermal alteration mapping from landsat8 data, sar. An understanding of hydrothermal alteration is of value because.
The occurrence of advanced argillic alteration assemblages along the ns, nnwsse, and ew. Advanced argillic alteration in the deeply buried magma. Geology and hydrothermal alteration of the low sulfidation payot. Hydrothermal alteration is a ch emical replacement of the original minerals in a rock by new minerals where a hydrothermal fluid delivers the chemical reactants and removes the aqueous reaction products. Mineral maps based on airborne visibleinfrared imaging spectrometer aviris data were used to study late miocene advanced argillic alteration at cuprite, nevada. Mineralogy and geochemistry of advanced argillic alteration zones lithocaps in greece advanced argillic alteration assemblages consisting of various amounts of quartz, diaspore, pyrophyllite. Hydrothermal alteration varies widely from district to district and among individual deposits, and the literature on this topic is voluminous. In argillic and phyllic alterations minerals mostly display aloh absorption feature in 1. Argillic alteration article about argillic alteration by. Porphyry cuau mineralisation, advanced argillic alteration.
The process generally occurs at low temperatures and may occur. These areas were differentiated in order to characterize and contrast the geochemical signatures of solids and waters in a variety of mineralized areas. Argillic horizons an overview sciencedirect topics. Advanced argillic lithocaps in the bolivian tinsilver belt. Soil orders typically formed in forested regions such as alfisols or spodosols, having distinct argillic or spodic subsoil horizons, cover 12%. Pdf ree mobility during advanced argillic alteration in some. They are located in the srednogorie tectonic zone, where host rocks are upper cretaceous intermediate. Pdf timing of advanced argillic alteration at nankivel hill. Mineralogy and geochemistry of advanced argillic alteration zones lithocaps in greece advanced argillic alteration assemblages consisting. Introduction advanced argillic alteration aaa systems have a good potential for exploration because of the close relationships with the ore deposits. Geochemistry of hydrothermal alteration in volcanic rocks. Pdf mineralogical study of the advanced argillic alteration zone. For best results viewing and printing pdf documents, it is recommended that you download the documents to your computer and open them with adobe reader.
Argillic alteration is hydrothermal alteration of wall rock which introduces clay minerals including kaolinite, smectite and illite. Sericitic and advanced argillic mineral assemblages and their. Although enargite has been observed petrographically. Argillic alteration is generally a low temperature event, and some may occur in atmospheric conditions. Endmember illite and rectorite is present in all samples from site d, reflecting high temperatures 220c and a progression from argillic to phyllic alteration at depth e. Diamond drilling at ohio creek in 19781981 by amoco minerals intersected low grade cuau 0. Mineralogical study of the advanced argillic alteration. Poorly or weakly developed soil orders such as entisols, aridisols, and inceptisols cover 38% of the ice free land surface. Argillic alteration grades to a propylitic zone farther. Hydrothermal alteration usgs publications repository. Argillic horizon synonyms, argillic horizon pronunciation, argillic horizon translation, english dictionary definition of argillic horizon.
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