Rankers and skeletal soils bedrock present at argillic alteration zones pirajno, 2008, and their widespread occurrence in the various studied sites, as well as in the local subsurface valentino and stanzione, 2003, 2004, is among the results that contrasts with this highsulfidation environment. The geology, structure and mineralisation of the oyu tolgoi. Brief description in hypogene parts of porphyry copper deposits, the copper occurs predominantly in chalcopyrite. 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. Identification of alteration zones with using aster data. Most silicification occurs in the intermediate and deep levels of the system and most argillized rock occurs high in the system. Carbonate replacement pbznag mineralization was discovered in bingham canyon in 1863, followed in 1864 by discovery of placer gold in bingham creek boutwell, 1905. Most metals were introduced during early potassic and sodicpotassic alteration, with significant enhancement of grade in areas overprinted by younger advanced argillic alteration. Approximately 8,000 tons of runofmine rom and crushed. The earliest signs of argillic alteration include the bleaching out of feldspars. Highgrade cuau mineralization is related to advanced argillic alteration, which comprises a core of pyrophyllite alteration associated with chalcopyrite, bounded to the west by an. Alteration zones albite, epidote, chlorite propylitic chloritic chlorite argillic clays, no mica sericitic mica potassic adularia silicic silica.
Hydrothermal alteration and mineralization at sar cheshmeh occur as stockworks, which were broadly synchronous with the granitoid intrusives in their emplacement. Advanced argillic lithocaps in the bolivian tinsilver belt. Darrehzar deposit is located in central iranian volcanic belt ranjbar et al. Argillic alteration is hydrothermal alteration of wall rock which introduces clay minerals including kaolinite, smectite and illite. Details on alteration and mineralisation mineralogy and distribution are provided and. Argillic alteration accompanies elevated gold grades and possibly ore. Geochemistry, mineralization and alteration zones of. However, argillic alteration is difficult to distinguish from supergene weathering of the primary alteration type. Geology and magmatichydrothermal evolution of the giant. Gsa 2000b unusual advanced argillic alteration of the sw. At depth all zones thought to merge into a single quartzksparsericitechlorite assemblage. The bingham canyon porphyry cumoau deposit is located in the central part of the oquirrh mountains, 30 km southwest of salt lake city, utah. Copper may also be introduced during overprinting phyllicargillic alteration. Rankers and skeletal soils bedrock present at targets.
Aslett william bill peppin oliver weatherbee spectir corporation. An assessment on the potential of mapping hydrothermal alteration. Locally, vein alteration envelopes, both edm and sericiticargillic main stage envelopes, overprint this pervasive biotitization of the host rock. On the southwestern margin of the gic two stages of anomalous advanced argillic alteration are localized within the dalam that appear to be associated with gold concentrations exceeding 9 gt. In other hydrothermal systems, it has been observed as in acoculco that advanced argillic alteration is depleted in hree and silicic alteration in lree fulignati et al.
Sericitic and advanced argillic mineral assemblages and their. Mixedlayer illitesmectite is the dominant product of argillic alteration at creede. Stratigraphy in the light of thedetailed work involved. Quartzadularia alteration is common in alkalichloride systems and alunite is common in acidsulfate systems. Geology of the bingham canyon porphyry cumoau deposit.
Pearl, and civit cat pits, which will eventually merge into a single pit. The gold king and davis lodes consist of two subparallel veins merging downward. Mineralization is largely controlled by the northwest striking. I prefer qpdf, the structural, contentpreserving pdf file transformer. Pdf mapping argillic and advanced argillic alteration in volcanic.
Silicification and argillization are the two dominant facies of hydrothermal alteration associated with the deposit. Pdf timing of advanced argillic alteration at nankivel hill. Mapping argillic and advanced argillic alteration in. Mineralization and alteration of a modern seafloor massive. Geochemical indicators for mapping of advanced argillic alteration and related alterations in lithocaps. A recent study mars and rowan, 2010, which compares aster image spectra to a spectral library for two alteration areas e. The supergene processes in the mineralized area due to the action of meteoric waters containing dissolved sulfate, oxygen and carbon dioxide of. Thereafter, with the extrusion of altering regions to be used for further investigations and the segregation and zone segmentation of the altering regions, use of data with high aster spectral resolution was made. 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.
However three strong chargeability anomalies are apparent from an elevation of 3,700m and tend to increase in strength and tend to merge at around 3,600m elevation. Geology of the pebble porphyry cuaumo deposit, southwest. Argillic alteration is generally a low temperature event, and some may occur in atmospheric conditions. Advanced argillic lithocaps form in higher topographic levels from the condensation of magmatic vapors into surface waters, and slightly postdate the potassic alteration in the porphyry environment and the advanced argillic alteration in the high sulphidation environment 8,63. The oyu tolgoi porphyry coppergoldmolybdenum deposits are located in the south gobi desert of mongolia 4301. Geology of the pebble porphyry cuaumo deposit, southwest alaska. Argillic alteration argillic alteration that surrounds some sulfide deposits may be. Construction of the red chris mine commenced in may 2012 and was completed in november 2014. A copy of this report is submitted as a computer readable file in adobe acrobat pdf format. Gray white argillic alteration is prominant over short intervals, less than 40 cm, usually surrounding fault zones. The introduction of promising mineral zones bidkhan area. Argillic grades into phyllic alteration at higher temperatures in an ore deposit hydrothermal system. Circulating ground waters are the principal agents responsible for the oxidation of minerals in the supergene zone. For the main stage features, alteration envelopes in the.
E, approximately 550 km due south of the capital, ulaanbaatar, and 80 km north of the chinese border. Advanced argillic alteration comprises a core of pyrophyllite alteration associated with chalcopyrite, bounded to the west by an upwardflaring zone of sericite alteration which contains hypogene bornite, digenite, covellite, and trace enargite and tennantite. The cuaumo deposit lies at the center of a large polymetallic district, which includes proximal pbznag replacement and distal sedimenthosted gold mineralization. Effective date december 22, 2017 issue date february 22, 2018. The general attributes of porphyry copper deposits are summarized below. The geology, structure and mineralisation of the oyu. Merge to andesites continuous feeding from depth into a.
Advanced argillic lithocaps in the bolivian tinsilver. Geology of the pebble porphyry cuaumo deposit, southwest alaska brian a. Locally, vein alteration envelopes, both edm and sericitic argillic main stage envelopes, overprint this pervasive biotitization of the host rock. Mapping hydrothermal alteration using remote sensing. Advanced argillic alteration occurs under lower ph and higher temperature conditions. Olson,4 and mark rebagliati2 1codes, arc centre for excellence in ore deposits, university of tasmania, hobart, tasmania 7001, australia 2hunter dickinson inc, vancouver, british columbia v6e 4h1, canada.
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. Preliminary model of porphyry copper deposits usgs. Oct 07, 2017 argillic alteration is hydrothermal alteration of wall rock which introduces clay minerals including kaolinite, smectite and illite. The process generally occurs at low temperatures and may occur. Kaolinite and dickite occur at lower temperatures whereas pyrophyllite and andalusite occur under high temperature conditions t 300c. Argillic alteration is hydrothermal alteration citation needed of wall rock which introduces clay minerals including kaolinite, smectite and illite. The distribution and behaviour of major and trace elements in the main zones of hydrothermal alteration propylite, sericite and advanced argillic in the area of breznik town have been studied, coupled with the chemical composition of alunite group minerals and their isotope geochemistry. Characteristics of supergene alteration in the binamar area.
A map of hydrothermal alteration assemblages covering. This zone which also is known as urumiehdokhtar magmatic assemblage shahabpour, 1991 is aligned parallel to the zagros thrust zone and also to the prevalent fold axes in the. Mapping argillic and advanced argillic alteration in volcanic. Resolution contains fairly high levels of fluorine. Possible submarine advanced argillic alteration at the. Alteration at the basin lake prospect occurs over a strike length of 1. Shield volcanoes basaltic volcanoes university at buffalo. Copper may also be introduced during overprinting phyllic argillic alteration events. Mining activities have focused on both the east and main zones, which will eventually merge to form one pit. Figures 24 show the chargeability anomalies at depth slices of 3,700m, 3,650m and 3,600m.
In order to uncompress all or most of the content streams and to get a nicer representation of the pdf file structure, we could use mutool clean d, podofouncompress or qpdf qdf. Advanced argillic alteration follows the naming convention of meyer and hemley 1967, although there are some differences noted in pebble alteration. Fc soil classification soil classes soils with well aerated subsoil soils with poorly aerated subsoil flushed peatlands unflushed peatlands manmade soils mining quarry spoil, brownfield sites etc. Argillicadvanced argillic alteration open energy information. Argillic alteration is hydrothermal alteration of wall rock which introduces clay minerals. Pdf geochemistry of advanced argillic altered rocks in. Geology of the bingham canyon porphyry cumoau deposit, utah. 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 by barnaby w. Early hydrothermal alteration was predominantlypotassicandpropyliticbutwasfollowedlater by phyllic, silicic and argillic alterations 33. Unusual advanced argillic alteration of the sw rim of the grasberg cuau porphyry deposit, irian jaya, indonesia.
Argillic alteration is representative of supergene environments where low temperature groundwater becomes acidic. They represent the largest highgrade group of palaeozoic porphyry deposits currently known in the world. Possible submarine advanced argillic alteration at the basin. The distribution of alterationmineralization features are illustrated along two, roughly perpendicular fences of drill holes that were logged with concurrent mineral identifications made with a pima. Pdf timing of advanced argillic alteration at nankivel. 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. Plant commissioning commenced in late 2014 and red chris produced its first copper concentrate on february 17, 2015. Reey, ti, and p remobilization in magmatic rocks by. Pdf rockwell and hofstra 2009a published preliminary results of a mineral mapping survey in southwestern utah derived from spectroscopic analysis of. This system appears to have the best economic potential on the property both with quartz veining and widespread argillic alteration. Hydrothermal alteration mapping from landsat8 data, sar.
This style silicification of the wallrock was limited in extent, extending less than 30 cm out from faults or shear zones. Argillic horizons and claysized particles an alternative. A wellpreserved lithocap at potosi is dominated by vuggy residual quartz and contained the. The bingham canyon cumoau deposit is located at the head of bingham canyon in the central part of the oquirrh mountains, 30 km southwest of salt lake city, utah fig.
Argillic alteration and ore mineralization at the contact between tuff and conglomerate. The main alteration minerals are hematite, magnetite, muscovite and quartz. 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. Modeling the formation of advanced argillic lithocaps. Generation of acid waters is the most important factor to form and develop supergene alteration. 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. Gold deposition at gold king, silverton caldera, colorado zobodat. Copper may also be introduced during overprinting phyllicargillic alteration events. Nev2009102 renewal 2018, fact sheet revision 00 page 4 of 12 p. These chemical signatures can be used to constrain. Fact sheet pursuant to nevada administrative code nac 445a. Comparison of main stage and premain stage alteration.
Zones of advanced argillic alteration constituting lithocaps are commonplace in the shallow parts of porphyry copper systems. 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. Characteristics of supergene alteration in the binamar. Pdf geochemical indicators for mapping of advanced argillic. Advanced argillic and sericitic alteration in the buckskin.
Most of the advanced argillic assemblages at resolution formed at relatively low temperatures, stable with kaolinite and dickite. Argillic alteration article about argillic alteration by. We show that acidic hydrothermal fluids at resolution formed a variety of vein types and mineral assemblages, though some uncertainty remains in defining assemblages. Advanced argillic alteration forms at higher temperatures and lower ph conditions e. The basin lake coppergold prospect lies in western tasmanias mount read volcanics and is hosted in a series of calcalkaline andesites, quartzfeldspar porphyries, mudstones, carbonates, and sandstones between the tyndall group and the central volcanic complex. Pixel purity index ppi and nd visualize method the pixel purity index ppi is used to find the most spectrally pure extreme pixels in multispectral and. The process generally occurs at low temperatures and may occur in atmospheric conditions. Veins with assemblages characteristic of advanced argillic alteration consistently offset veins associated with sericitic alteration.
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