Intresting to note the simularitys in the Olympic Dam on the upper portion of this post along with the results so far that KAT released on the RR witch I posted below
Fluid Evolution and Origins of Iron Oxide Cu-Au Prospects in the Olympic Dam District, Gawler Craton, South Australia
Evgeniy N. Bastrakov and Roger G. Skirrow
Geoscience Australia, GPO Box 378, Canberra, A.C.T., Australia 2601
Garry J. Davidson
University of Tasmania, Private Box 79, Hobart, Tasmania, Australia 7001
Corresponding author: e-mail, evgeniy.bastrakov@ga.gov.au
Geologic observations suggest two stages of hydrothermal activity at a number of presently subeconomic iron oxide copper-gold systems in the Olympic Dam district, eastern Gawler craton. They contain high-, and moderate- to low-temperature Fe oxide-rich hydrothermal alteration. The mineral assemblages include magnetite-calc-silicate-alkali feldspar ± Fe-Cu sulfides and hematite-sericite-chlorite-carbonate ± Fe-Cu sulfides ± U, REE minerals. In all documented prospects, the minerals of the hematitic assemblages replace the minerals of the magnetite-rich assemblages.
The bulk of the subeconomic Cu-Au mineralization is associated with the hematitic alteration assemblages. Microanalysis by proton ion probe (PIXE) of hypersaline fluid inclusions in magnetite-rich assemblages, however, demonstrates that significant amounts of copper (>500 ppm) were transported by the early-stage high-temperature (>400°C) fluids responsible for the magnetite-rich alteration. These brine inclusions contain multiple solid phases (liquid + vapor + multiple solids) including chalcopyrite in some cases. In comparison, inclusions of the hematitic stage are relatively simple liquid + vapor types, with homogenization temperatures of 200° to 300°C and containing 1 to 8 wt percent NaCl equiv. The Br/Cl ratios of the magnetite-forming fluids measured by PIXE lie beyond the range of typical magmatic and/or mantle values, allowing for the possibility that the fluids originated as brines from a sedimentary basin or the crystalline basement.
Sulfur isotope compositions of chalcopyrite and pyrite demonstrate that sulfur in both alteration assemblages was derived either from cooling magmas and/or crystalline igneous rocks carried by relatively oxidized fluids (SO42– H2S, 34Ssulfides from –5 to +2) or from crustal sedimentary rocks (34Ssulfides from +5 to +10). Oxygen and hydrogen isotope compositions of waters calculated for minerals of the magnetite-rich assemblage have 18O values of +7.7 to +12.8 per mil and D values of –15 to –21 per mil. The only available 18O and Dfluid values for the hematitic assemblage are +4.7 and –9 per mil, respectively. The isotopic compositions of both fluids, coupled with the available literature data, can be explained in terms of fluid reequilibration with felsic Gawler Range Volcanics or other felsic igneous rocks in the region and with metasedimentary rocks of the Wallaroo Group at low water-to-rock ratios prior to their arrival at the mineralization sites.
The lack of significant copper mineralization associated with magnetite-forming fluids that carried copper suggests that there was no effective mechanism of saturation of copper minerals or the quantity of these fluids was not sufficient to produce appreciable copper mineralization. Association of the copper-gold mineralization with the hematitic alteration in the subeconomic prospects can be explained by a two-stage model in which preexisting hydrothermal magnetite with minor associated copper-gold mineralization was flushed by late-stage oxidized brines that had extensively reacted with sedimentary or metamorphic rocks. The reduction of these brines, driven by conversion of magnetite to hematite, resulted in precipitation of copper and gold. The oxidized brines may have contributed additional copper and gold to the system in addition to upgrading preexisting subeconomic Cu-Au mineralization. When compared to published models for the Olympic Dam deposit, the new data for fluids in subeconomic Fe-oxide Cu-Au prospects of the Olympic Dam district indicate the diversity of origins of iron oxide-copper-gold systems, even within the same geologic region.
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D. I. Groves, F. P. Bierlein, L. D. Meinert, and M. W. Hitzman
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R. G. Skirrow, R. G. Skirrow, and G. J. Davidson
A Special Issue Devoted to Proterozoic Iron Oxide Cu-Au-(U) and Gold Mineral Systems of the Gawler Craton: Preface
Economic Geology, December 1, 2007; 102(8): 1373 - 1375.
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N. G. Direen, N. G. Direen, and P. Lyons
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R. G. Skirrow, R. G. Skirrow, E. N. Bastrakov, K. Barovich, G. L. Fraser, R. A. Creaser, C. M. Fanning, O. L. Raymond, and G. J. Davidson
Timing of Iron Oxide Cu-Au-(U) Hydrothermal Activity and Nd Isotope Constraints on Metal Sources in the Gawler Craton, South Australia
Economic Geology, December 1, 2007; 102(8): 1441 - 1470.
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G. J. Davidson, G. J. Davidson, H. Paterson, S. Meffre, and R. F. Berry
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Economic Geology, December 1, 2007; 102(8): 1471 - 1498.
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KAT Exploration Inc. (PINKSHEETS: KATX) www.katexploration.com
KAT Exploration Inc. (PINKSHEETS: KATX) is pleased to inform its shareholders and the investment community that partial analytical results have been received from two diamond drill holes completed at its 100% owned Rusty Ridge property. Drilling tested two separate target areas: a deep coincident gravity and magnetics anomaly in drill hole RR10-01 and Rare Earth Element (REE) plus gold potential within altered peralkaline felsic volcanic rocks in RR10-02.
Hole RR10-02 intersected variably altered and mineralized peralkaline felsic volcanic rocks throughout the upper 245 meters of the 344 meter long hole. Initial ICP analytical results indicated elevated lanthanum and cerium through several sections; these, along with other selected sections of the drill hole were sent for a complete suite of rare earth and associated elements. Results have been received for the upper section of the drill hole from 30 to 40.1m. The analyses indicate a 7.5m interval from 30.0 to 37.5m having elevated rare earth elements and zircon, returning a weighted average of 0.164% TREO (including yttrium) consisting of 0.113% LREO and 0.051% HREO (including yttrium). The results also returned 0.268% zirconium dioxide, 0.039% Nb2O5 (niobium oxide) and 0.022% rubidium. A table showing all analyses will be posted to our website in the near future. Additional samples are being analyzed for the rare earth and associated elements from other deeper sections of the hole and will be reported when received.
Hole RR10-01, approximately 500 meters south of RR10-02, was drilled to a depth of 719.3 meters to test a coincident gravity and magnetics anomaly. The hole intersected mafic volcanic rocks, conglomerates and mafic intrusive rocks that contain indications of sub-economic copper mineralization throughout most of the drill hole (including native copper and chalcopyrite). The conglomerate unit is also strongly hematite altered, which could explain the gravity anomaly. The upper part of the magnetics geophysical anomaly is coincident with a thick magnetic mafic dyke.
Ken Stead, President/CEO, states: "We are very encouraged by the presence of rare earth element rich rocks at Rusty Ridge and are eagerly awaiting the next batch of assays to find out just how consistent REE are at depth and if the grades improve. While there is much work yet to be carried out to determine the significance of this discovery, we feel we are in the very early stages of a most interesting project."
The property will be re-examined in light of potential for additional rare earth element mineralization. Further testing of the main Rusty Ridge zone as well as other targets including strong IP (Induced Polarization) anomalies, some of which are coincident with gravity anomalies, will be considered.
The property is located near roads, seaports and power infrastructure, improving the economics of any mineral deposits found.
Rare earth elements reported were analyzed by Acme Labs in Vancouver using their Group 4B analytical method, which produces accurate analyses of the rare earth and associated elements.
The Company's exploration work on the Rusty Ridge Project is supervised by Barry A. Sparkes, B.Sc. (Hons.), P.Geo. and J. Wayne Pickett, M.Sc. P.Geo., both members in good standing of the Professional Engineers and Geoscientists of Newfoundland and Labrador. Mr. Sparkes and Mr. Pickett have verified that the results presented above have been accurately summarized from the official assay certificates provided to the Company.
This press release contains forward-looking information within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934 and is subject to the Safe Harbor created by those sections. This material contains statements about expected future events and/or financial results that are forward-looking in nature and subject to risks and uncertainties. Such forward-looking statements by definition involve risks, uncertainties and other factors, which may cause the actual results, performance or achievements of Kat Exploration Inc. to be materially different from the statements made herein.
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