<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<title>UTas ePrints - Hydrothermal Alteration and Volatile Element Halos for the Rosebery K Lens Volcanic-Hosted Massive Sulfide Deposit, Western Tasmania</title>
<script type="text/javascript" src="http://eprints.utas.edu.au/javascript/auto.js"><!-- padder --></script>
<style type="text/css" media="screen">@import url(http://eprints.utas.edu.au/style/auto.css);</style>
<style type="text/css" media="print">@import url(http://eprints.utas.edu.au/style/print.css);</style>
<link rel="icon" href="/images/eprints/favicon.ico" type="image/x-icon" />
<link rel="shortcut icon" href="/images/eprints/favicon.ico" type="image/x-icon" />
<link rel="Top" href="http://eprints.utas.edu.au/" />
<link rel="Search" href="http://eprints.utas.edu.au/cgi/search" />
<meta content="Large, R.R." name="eprints.creators_name" />
<meta content="Allen, R.L." name="eprints.creators_name" />
<meta content="Blake, M.D." name="eprints.creators_name" />
<meta content="Herrmann, W." name="eprints.creators_name" />
<meta content="Ross.Large@utas.edu.au" name="eprints.creators_id" />
<meta name="eprints.creators_id" />
<meta name="eprints.creators_id" />
<meta name="eprints.creators_id" />
<meta content="article" name="eprints.type" />
<meta content="2007-09-05" name="eprints.datestamp" />
<meta content="2008-01-23T05:11:03Z" name="eprints.lastmod" />
<meta content="show" name="eprints.metadata_visibility" />
<meta content="Hydrothermal Alteration and Volatile Element Halos for the
Rosebery K Lens Volcanic-Hosted Massive Sulfide Deposit, Western Tasmania" name="eprints.title" />
<meta content="pub" name="eprints.ispublished" />
<meta content="260100" name="eprints.subjects" />
<meta content="restricted" name="eprints.full_text_status" />
<meta content="VHMS, Thallium, alteration index, Mt Read Volcanics, manganese, hydrothermal alteration, carbonate alteration, chlorite" name="eprints.keywords" />
<meta content="A detailed study of alteration mineralogy, mineral chemistry, and lithogeochemistry in the host rocks surrounding the A-B and K lenses at the north end of the Rosebery mine has revealed a series of overlapping alteration halos with characteristic mineralogy and geochemistry. The study involved logging and sampling from
nine drill holes spaced at varying distances from the A-B and K lenses. The stratiform Zn-Pb-Cu ore lenses
have a sheetlike morphology and are hosted by a mixed sequence of rhyolitic to dacitic massive mediumgrained
quartz-porphyritic pumice breccia, black mudstone, and crystal-rich volcaniclastic sandstone, overlying
a thick homogeneous sequence of rhyolitic pumice breccia.
The major alteration minerals at Rosebery are arranged in a complex series of zones passing away from the
deposit-quartz-sericite zone, Mn carbonate zone, chlorite zone, and outer sericite zone. The chlorite zone is
best developed in the immediate footwall below the copper-pyrite-rich ore lenses, whereas the strongest Mn
carbonate alteration occurs in the immediate hanging-wall volcanics or lateral to the ore lenses. The outermost
visible sericitic alteration extends about 60 to 100 m into the footwall, 10 to 20 m into the hanging wall, and
over 500 m along the upper contact of the footwall pumice breccias.
Thallium and antimony form the most extensive trace element halos related to the mineralization. Thallium
forms a halo that extends 200 to 300 m into the overlying volcanics and 60 to 100 m into the footwall. Anomalously
high thallium also occurs over 500 m along strike marking the contact between the footwall pumice breccias and the overlying volcaniclastic sandstones. Proximal to the ore lenses Tl and Sb values range from 10 to 100 ppm, compared to the halo zone where they vary from around 1 to 10 ppm.
Studies of alteration mineral chemistry at Rosebery have revealed some important relationships that may assist
exploration. The Mn content of alteration carbonate increases toward ore, both along strike and across
strike. Close to ore, alteration carbonates contain >20 mole percent MnCO3 (kutnahorite, rhodochrosite, Mn
siderite, and Mn ankerite), whereas at distances of 40 to 60 m across strike the mole percent MnCO3 in carbonate
drops to below 10 percent. At greater than 80 m, the carbonates are Mn-poor calcites and are commonly
located in synmetamorphic structures. White mica composition changes with stratigraphy and alteration
assemblages and may be related to the mineralizing event, although this has not been convincingly demonstrated.
Proximal white mica contains minor Ba substituting for octahedral Al. However, except for their Ba content, these phengetic white micas are similar to those found in nonmineralized areas of the Mount Read
Volcanics. Sodic white mica with up to 0.35 Na/(Na + K) and a low phengite content (<0.5 Fe + Mg cations)
occurs in a zone of volcanic sandstones and black slates overlying the ore deposit.
This research has lead to the development of a series of proximal, medial, and distal vectors useful for both
regional and mine-scale exploration. The most useful vectors, listed from proximal to distal, include Zn, Ba content
of white mica, Na2O, K2O, Ishikawa alteration index (AI), S/Na2O, Ba/Sr, Mn content of carbonate, Tl, and
Sb." name="eprints.abstract" />
<meta content="2001-08" name="eprints.date" />
<meta content="published" name="eprints.date_type" />
<meta content="Economic Geology" name="eprints.publication" />
<meta content="96" name="eprints.volume" />
<meta content="5" name="eprints.number" />
<meta content="1055-1072" name="eprints.pagerange" />
<meta content="10.2113/96.5.1055" name="eprints.id_number" />
<meta content="UNSPECIFIED" name="eprints.thesis_type" />
<meta content="TRUE" name="eprints.refereed" />
<meta content="0361-0128" name="eprints.issn" />
<meta content="http://dx.doi.org/10.2113/96.5.1055" name="eprints.official_url" />
<meta content="Allen, R.L., 1994a, Syn-volcanic, subseafloor replacement model for Rosebery and other massive sulfide ores [ext. abs.]: Contentious Issues in Tasmanian Geology Symposium, Geological Society of Australia Tasmanian Division, Extended Abstracts Volume, p. 89-91.
1994b, Volcanic facies analysis indicates large pyroclastic eruptions, sill complexes, syn-volcanic grabens, and subtle thrusts in the Cambrian Central Volcanic Complex volcanic centre, western Tasmania [ext. abs.]: Contentious Issues in Tasmanian Geology Symposium, Geological Society of Australia Tasmanian Division, Extended Abstracts Volume, p. 31-32.
-1997, Rosebery alteration study and regional alteration studies in the Mount Read Volcanics: The record of diagenetic alteration in the strongly deformed, felsic volcaniclastic succesion enclosing the Rosebery and Hercules
massive sulfide deposits: Australian Mineral Industry Research Association (AMIRA) project P439, Unpublished report 5, October 1997, p. 135-145.
Allen, R.L., and Cas, R.A.F., 1990, The Rosebery controversy: Distinguishing prospective submarine ignimbrite-like units from true subaerial ignimbrites
in the Rosebery-Hercules Zn-Cu-Pb massive sulfide district, Tasmania [abs.]: Australian Geological Convention, 10th, Hobart, Geological Society of Australia, Abstracts, p. 31-32.
Barrett, T.J., Thompson, J.F.H., and Sherlock, R.L., 1996, Stratigraphic, lithogeochemical and tectonic setting of the Kutcho Creek massive sulfide deposit, northern British Columbia: Exploration and Mining Geology, v. 5, p.
309-338.
Berry, R.F., and Keele, R.A., 1997, Cambrian tectonics and mineralization in western Tasmania: International Mining Geology Conference, 3rd, Launceston, November 1997, Australasian Institute of Mining and Metallurgy,
Proceedings, p. 13-16.
Brathwaite, R.L., 1972, The structure of the Rosebery ore deposit, Tasmania: Australasian Institute of Mining and Metallurgy, Proceedings, no. 241, p. 1-13.
-1974, The geology and origin of the Rosebery ore deposit, Tasmania: ECONOMIC GEOLOGY, v. 69, p. 1086-1101.
Crawford, A.J., Corbett, K.D., and Everard, J.L., 1992, Geochemistry of the Cambrian volcanic-hosted massive sulfide-rich Mount Read Volcanics, Tasmania, and some tectonic implications: ECONOMIC GEOLOGY,v. 87, p.
597-619.
Doyle, M.G., 2001, Volcanic influences on hydrothermal and diagenetic alteration: Evidence from the Highway-Reward deposit, Mount Windsor subprovince, Australia: ECONOMIC GEOLOGY, v. 96, p. 1133-1148.
Gee, C.E., 1970, The geochemistry of some black shales in relation to the origin of certain stratiform ore deposits in Tasmania: Unpublished Ph.D. thesis, Hobart, Tasmania, University of Tasmania, 205 p.
Gemmell, J.B., and Fulton, R., 2001, Geology, genesis, and exploration implications of the footwall and hanging-wall alteration associated with the Hellyer volcanic-hosted massive sulfide deposit, Tasmania, Australia: ECONOMIC
GEOLOGY, v. 96, p. 1003-1035.
Gifkins, C.C., and Allen, R.L., 2001, Textural and chemical characteristics of diagenetic and hydrothermal alteration in glassy volcanic rocks: Examples from the Mount Read Volcanics, Tasmania: ECONOMIC GEOLOGY, v. 96, p. 973-1002.
Gill, J.W., 1976, The Takiyuak metavolcanic belt: Geology, geochemistry and mineralisation: Unpublished Ph.D. thesis, Ottawa, Canada, Carleton University, 210 p.
Goodfellow, W.D., and Peter, J.M., 1994, Geochemistry of hydrothermally altered sediment, Middle Valley, northern Juan de Fuca Ridge: Proceedings of the Ocean Drilling Program, Scientific Results, v. 139, p. 207-290.
Green, G.R., and Iliff, G.D., 1989, Rosebery: Geological Society of Australia Special Publication 15, p. 132-137.
Green, G.R., Solomon, M., and Walshe, J.L., 1981, The formation of the volcanic-hosted massive sulfide ore deposit at Rosebery, Tasmania: ECONOMIC GEOLOGY, v. 76, p. 304-338.
Herrmann, W., Blake, M., Doyle, M., Huston, D., Kamprod, J., Merry, N., and Pontual, S., 2001, Short wavelength infrared (SWIR) spectral analysis of hydrothermal alteration zones associated with base metal sulfide deposits at Rosebery and Western Tharsis, Tasmania, and Highway-Reward, Queensland: ECONOMIC GEOLOGY, v. 96, p. 939-955.
Huston, D.L., and Kamprad, J., 2001, Zonation of alteration facies at Western Tharsis: Implications for the genesis of Cu-Au deposits in the Mount Lyell field, western Tasmania: ECONOMIC GEOLOGY, v. 96, p. 1123-1132.
Huston, D.L., and Large, R.R., 1987, The distribution, mineralogy and geochemistry of gold and silver in the north-end orebody, Rosebery mine, Tasmania: ECONOMIC GEOLOGY, v. 83, p. 1181-1192.
Ikramuddin, M., Asmeron, Y., Nordstrom, P.M., Kinart, K.P., Martin, W.M., Digby, S.J.M., Elder, D.D., Nijak, W.F., and Afemari, A.A., 1983, Thallium: A potential guide to mineral deposits: Journal of Geochemical Exploration,
v. 19, p. 465-490.
Ishikawa, Y., Sawaguchi, T., Iwaya, S., and Horiuchi, M., 1976, Delineation of prospecting targets for Kuroko deposits based in modes of volcanicsm of underlying dacite and alteration halos: Mining Geology, v. 26, p. 105-117
(in Japanese with English abs.).
Khin Zaw, 1991, The effect of Devonian metamorphism and metasomatism on the mineralogy and geochemistry of the Cambrian VMS deposits in the Rosebery-Hercules district, western Tasmania: Unpublished Ph.D. thesis, Hobart, Tasmania, University of Tasmania, 342 p.
Khin Zaw, Large, R.R., and Huston, D.L, 1997, Petrological and geochemical significance of a Devonian replacement zone in the Cambrian Rosebery VHMS deposit, western Tasmania: Canadian Mineralogist, v. 35, p. 1325-1350.
Khin Zaw, Huston, D.L., and Large, R.R., 1999, A chemical model for the Devonian remobilization process in the Cambrian volcanic-hosted massive sulfide Rosebery deposit, western Tasmania: ECONOMIC GEOLOGY, v. 94, p.529-546.
Large, R.R., 1990, The gold-rich sea-floor massive sulfide deposits of Tasmania: Geologische Rundshau, v. 79, p. 256-278.
-1992, Australian volcanic-hosted massive sulfide deposits: Features, styles and genetic models: ECONOMIC GEOLOGY, v. 87, p. 471-510.
Large, R.R., and McGoldrick, P.J., 1998, Lithogeochemical halos and geochemical vectors to stratiform sediment hosted Zn-Pb-Ag deposits. Part 1: Lady Loretta deposit, Queensland: Journal of Geochemical Exploration, v.
63, p. 37-56.
Large, R.R., Bull, S.W., and McGoldrick, P.J., 2000, Lithogeochemical halos and geochemical vectors to stratiform sediment hosted Zn-Pb-Ag deposits.
Part 2: HYC deposit, McArthur River, Northern Territory: Journal of Geochemical Exploration, v. 68, p. 105-126.
Large, R.R., Gemmell, J.B., Paulick, H., and Huston, D.L., 2001, The alteration box plot: A simple approach to understanding the relationship between alteration mineralogy and lithogeochemistry associated with volcanic-
hosted massive sulfide deposits: ECONOMIC GEOLOGY, v. 96, p.
957-971.
Lydon, J.W., 1988, Ore deposit models #14. Volcanogenic massive sulfide deposits Part 2: Genetic models: Geoscience Canada, v. 15, p. 43-65.
MacLean, W.H., and Barrett, T.J., 1993, Lithogeochemical techniques using immobile elements: Journal of Geochemical Exploration, v. 48, p. 109-133.
McLeod, R.L., and Stanton, R.L., 1984, Phyllosilicates and associated minerals in some Paleozoic stratiform sulfide deposits of southeastern Australia: ECONOMIC GEOLOGY, v. 79, p. 1-22.
McLeod, R.L., Gabell, A.R., Green, A.A., and Gardavsky, V., 1987, Chlorite infrared spectral data as proximity indicators of volcanogenic massive sulfide
mineralisation: Pacific Rim Congress 87, Gold Coast, August 1987, Australasian Institute of Mining and Metallurgy, Proceedings, p. 321-324.
Naschwitz, W., and Van Moort, J.C., 1991, Geochemistry of wallrock alteration, Rosebery, Tasmania, Australia: Applied Geochemistry, v. 6, p. 267-278.
Paulick, H., Herrmann, W., and Gemmell, J.B., 2001, Alteration of felsic volcanics hosting the Thalanga massive sulfide deposit, North Queensland, Australia: Geochemical proximity indicators to ore: ECONOMIC GEOLOGY, v. 96, p. 1175-1200.
Pwa, A., Naschwitz, W., Hotchkis, M., and Van Moort, J.C., 1992, Exploration rock geochemistry in the Rosebery mine area, western Tasmania: Tasmanian Department Mines, Geological Survey Bulletin, v. 70, p. 7-16.
Reid, L.G., 1993, Aspects of north-end mineralisation, Rosebery mine, western Tasmania: Unpublished M.Sc. thesis, Hobart, Tasmania, University of Tasmania, 82 p.
Shaw, D.M., 1952, The geochemistry of thallium: Geochimica et Cosmochimica Acta, v. 2, p. 118-154.
Smith, R.N., 1973, Trace element distributions within some major stratiform orebodies: Unpublished B.Sc. Honors thesis, Parkville, Victoria, University of Melbourne, 189 p.
Smith, R.N., and Huston, D.L., 1992, Distribution and association of selected trace elements at the Rosebery deposit, Tasmania: ECONOMIC GEOLOGY,v. 87, p. 706-719.
Whitford, D.J., McPherson, W.P.A., and Wallace, D.B., 1989, Geochemistry of the host rocks of the volcanogenic massive sulfide deposit at Que River, Tasmania: ECONOMIC GEOLOGY, v. 84, p. 1-21." name="eprints.referencetext" />
<meta content="Large, R.R. and Allen, R.L. and Blake, M.D. and Herrmann, W. (2001) Hydrothermal Alteration and Volatile Element Halos for the Rosebery K Lens Volcanic-Hosted Massive Sulfide Deposit, Western Tasmania. Economic Geology, 96 (5). pp. 1055-1072. ISSN 0361-0128" name="eprints.citation" />
<meta content="http://eprints.utas.edu.au/1876/1/Large_et_al_2001_ECON_GEOL.pdf" name="eprints.document_url" />
<link rel="schema.DC" href="http://purl.org/DC/elements/1.0/" />
<meta content="Hydrothermal Alteration and Volatile Element Halos for the
Rosebery K Lens Volcanic-Hosted Massive Sulfide Deposit, Western Tasmania" name="DC.title" />
<meta content="Large, R.R." name="DC.creator" />
<meta content="Allen, R.L." name="DC.creator" />
<meta content="Blake, M.D." name="DC.creator" />
<meta content="Herrmann, W." name="DC.creator" />
<meta content="260100 Geology" name="DC.subject" />
<meta content="A detailed study of alteration mineralogy, mineral chemistry, and lithogeochemistry in the host rocks surrounding the A-B and K lenses at the north end of the Rosebery mine has revealed a series of overlapping alteration halos with characteristic mineralogy and geochemistry. The study involved logging and sampling from
nine drill holes spaced at varying distances from the A-B and K lenses. The stratiform Zn-Pb-Cu ore lenses
have a sheetlike morphology and are hosted by a mixed sequence of rhyolitic to dacitic massive mediumgrained
quartz-porphyritic pumice breccia, black mudstone, and crystal-rich volcaniclastic sandstone, overlying
a thick homogeneous sequence of rhyolitic pumice breccia.
The major alteration minerals at Rosebery are arranged in a complex series of zones passing away from the
deposit-quartz-sericite zone, Mn carbonate zone, chlorite zone, and outer sericite zone. The chlorite zone is
best developed in the immediate footwall below the copper-pyrite-rich ore lenses, whereas the strongest Mn
carbonate alteration occurs in the immediate hanging-wall volcanics or lateral to the ore lenses. The outermost
visible sericitic alteration extends about 60 to 100 m into the footwall, 10 to 20 m into the hanging wall, and
over 500 m along the upper contact of the footwall pumice breccias.
Thallium and antimony form the most extensive trace element halos related to the mineralization. Thallium
forms a halo that extends 200 to 300 m into the overlying volcanics and 60 to 100 m into the footwall. Anomalously
high thallium also occurs over 500 m along strike marking the contact between the footwall pumice breccias and the overlying volcaniclastic sandstones. Proximal to the ore lenses Tl and Sb values range from 10 to 100 ppm, compared to the halo zone where they vary from around 1 to 10 ppm.
Studies of alteration mineral chemistry at Rosebery have revealed some important relationships that may assist
exploration. The Mn content of alteration carbonate increases toward ore, both along strike and across
strike. Close to ore, alteration carbonates contain >20 mole percent MnCO3 (kutnahorite, rhodochrosite, Mn
siderite, and Mn ankerite), whereas at distances of 40 to 60 m across strike the mole percent MnCO3 in carbonate
drops to below 10 percent. At greater than 80 m, the carbonates are Mn-poor calcites and are commonly
located in synmetamorphic structures. White mica composition changes with stratigraphy and alteration
assemblages and may be related to the mineralizing event, although this has not been convincingly demonstrated.
Proximal white mica contains minor Ba substituting for octahedral Al. However, except for their Ba content, these phengetic white micas are similar to those found in nonmineralized areas of the Mount Read
Volcanics. Sodic white mica with up to 0.35 Na/(Na + K) and a low phengite content (<0.5 Fe + Mg cations)
occurs in a zone of volcanic sandstones and black slates overlying the ore deposit.
This research has lead to the development of a series of proximal, medial, and distal vectors useful for both
regional and mine-scale exploration. The most useful vectors, listed from proximal to distal, include Zn, Ba content
of white mica, Na2O, K2O, Ishikawa alteration index (AI), S/Na2O, Ba/Sr, Mn content of carbonate, Tl, and
Sb." name="DC.description" />
<meta content="2001-08" name="DC.date" />
<meta content="Article" name="DC.type" />
<meta content="PeerReviewed" name="DC.type" />
<meta content="application/pdf" name="DC.format" />
<meta content="http://eprints.utas.edu.au/1876/1/Large_et_al_2001_ECON_GEOL.pdf" name="DC.identifier" />
<meta content="http://dx.doi.org/10.2113/96.5.1055" name="DC.relation" />
<meta content="Large, R.R. and Allen, R.L. and Blake, M.D. and Herrmann, W. (2001) Hydrothermal Alteration and Volatile Element Halos for the Rosebery K Lens Volcanic-Hosted Massive Sulfide Deposit, Western Tasmania. Economic Geology, 96 (5). pp. 1055-1072. ISSN 0361-0128" name="DC.identifier" />
<meta content="http://eprints.utas.edu.au/1876/" name="DC.relation" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1876/BibTeX/epprod-eprint-1876.bib" title="BibTeX" type="text/plain" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1876/ContextObject/epprod-eprint-1876.xml" title="OpenURL ContextObject" type="text/xml" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1876/ContextObject::Dissertation/epprod-eprint-1876.xml" title="OpenURL Dissertation" type="text/xml" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1876/ContextObject::Journal/epprod-eprint-1876.xml" title="OpenURL Journal" type="text/xml" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1876/DC/epprod-eprint-1876.txt" title="Dublin Core" type="text/plain" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1876/DIDL/epprod-eprint-1876.xml" title="DIDL" type="text/xml" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1876/EndNote/epprod-eprint-1876.enw" title="EndNote" type="text/plain" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1876/HTML/epprod-eprint-1876.html" title="HTML Citation" type="text/html; charset=utf-8" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1876/METS/epprod-eprint-1876.xml" title="METS" type="text/xml" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1876/MODS/epprod-eprint-1876.xml" title="MODS" type="text/xml" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1876/RIS/epprod-eprint-1876.ris" title="Reference Manager" type="text/plain" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1876/Refer/epprod-eprint-1876.refer" title="Refer" type="text/plain" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1876/Simple/epprod-eprint-1876text" title="Simple Metadata" type="text/plain" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1876/Text/epprod-eprint-1876.txt" title="ASCII Citation" type="text/plain; charset=utf-8" />
<link rel="alternate" href="http://eprints.utas.edu.au/cgi/export/1876/XML/epprod-eprint-1876.xml" title="EP3 XML" type="text/xml" />
</head>
<body bgcolor="#ffffff" text="#000000" onLoad="loadRoutine(); MM_preloadImages('images/eprints/ePrints_banner_r5_c5_f2.gif','images/eprints/ePrints_banner_r5_c7_f2.gif','images/eprints/ePrints_banner_r5_c8_f2.gif','images/eprints/ePrints_banner_r5_c9_f2.gif','images/eprints/ePrints_banner_r5_c10_f2.gif','images/eprints/ePrints_banner_r5_c11_f2.gif','images/eprints/ePrints_banner_r6_c4_f2.gif')">
<div class="ep_noprint"><noscript><style type="text/css">@import url(http://eprints.utas.edu.au/style/nojs.css);</style></noscript></div>
<table width="795" border="0" cellspacing="0" cellpadding="0">
<tr>
<td><script language="JavaScript1.2">mmLoadMenus();</script>
<table border="0" cellpadding="0" cellspacing="0" width="795">
<!-- fwtable fwsrc="eprints_banner_final2.png" fwbase="ePrints_banner.gif" fwstyle="Dreamweaver" fwdocid = "1249563342" fwnested="0" -->
<tr>
<td><img src="/images/eprints/spacer.gif" width="32" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="104" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="44" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="105" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="41" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="16" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="68" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="68" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="68" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="82" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="69" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="98" height="1" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="1" height="1" border="0" alt="" /></td>
</tr>
<tr>
<td colspan="12"><img name="ePrints_banner_r1_c1" src="/images/eprints/ePrints_banner_r1_c1.gif" width="795" height="10" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="1" height="10" border="0" alt="" /></td>
</tr>
<tr>
<td rowspan="6"><img name="ePrints_banner_r2_c1" src="/images/eprints/ePrints_banner_r2_c1.gif" width="32" height="118" border="0" alt="" /></td>
<td rowspan="5"><a href="http://www.utas.edu.au/"><img name="ePrints_banner_r2_c2" src="/images/eprints/ePrints_banner_r2_c2.gif" width="104" height="103" border="0" alt="" /></a></td>
<td colspan="10"><img name="ePrints_banner_r2_c3" src="/images/eprints/ePrints_banner_r2_c3.gif" width="659" height="41" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="1" height="41" border="0" alt="" /></td>
</tr>
<tr>
<td colspan="3"><a href="http://eprints.utas.edu.au/"><img name="ePrints_banner_r3_c3" src="/images/eprints/ePrints_banner_r3_c3.gif" width="190" height="31" border="0" alt="" /></a></td>
<td rowspan="2" colspan="7"><img name="ePrints_banner_r3_c6" src="/images/eprints/ePrints_banner_r3_c6.gif" width="469" height="37" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="1" height="31" border="0" alt="" /></td>
</tr>
<tr>
<td colspan="3"><img name="ePrints_banner_r4_c3" src="/images/eprints/ePrints_banner_r4_c3.gif" width="190" height="6" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="1" height="6" border="0" alt="" /></td>
</tr>
<tr>
<td colspan="2"><img name="ePrints_banner_r5_c3" src="/images/eprints/ePrints_banner_r5_c3.gif" width="149" height="1" border="0" alt="" /></td>
<td rowspan="2" colspan="2"><a href="/information.html" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821132634_0,0,25,null,'ePrints_banner_r5_c5');MM_swapImage('ePrints_banner_r5_c5','','/images/eprints/ePrints_banner_r5_c5_f2.gif',1);"><img name="ePrints_banner_r5_c5" src="/images/eprints/ePrints_banner_r5_c5.gif" width="57" height="25" border="0" alt="About" /></a></td>
<td rowspan="2"><a href="/view/" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821133021_1,0,25,null,'ePrints_banner_r5_c7');MM_swapImage('ePrints_banner_r5_c7','','/images/eprints/ePrints_banner_r5_c7_f2.gif',1);"><img name="ePrints_banner_r5_c7" src="/images/eprints/ePrints_banner_r5_c7.gif" width="68" height="25" border="0" alt="Browse" /></a></td>
<td rowspan="2"><a href="/perl/search/simple" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821133201_2,0,25,null,'ePrints_banner_r5_c8');MM_swapImage('ePrints_banner_r5_c8','','/images/eprints/ePrints_banner_r5_c8_f2.gif',1);"><img name="ePrints_banner_r5_c8" src="/images/eprints/ePrints_banner_r5_c8.gif" width="68" height="25" border="0" alt="Search" /></a></td>
<td rowspan="2"><a href="/perl/register" onMouseOut="MM_swapImgRestore();MM_startTimeout();" onMouseOver="MM_showMenu(window.mm_menu_1018171924_3,0,25,null,'ePrints_banner_r5_c9');MM_swapImage('ePrints_banner_r5_c9','','/images/eprints/ePrints_banner_r5_c9_f2.gif',1);"><img name="ePrints_banner_r5_c9" src="/images/eprints/ePrints_banner_r5_c9.gif" width="68" height="25" border="0" alt="register" /></a></td>
<td rowspan="2"><a href="/perl/users/home" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821133422_4,0,25,null,'ePrints_banner_r5_c10');MM_swapImage('ePrints_banner_r5_c10','','/images/eprints/ePrints_banner_r5_c10_f2.gif',1);"><img name="ePrints_banner_r5_c10" src="/images/eprints/ePrints_banner_r5_c10.gif" width="82" height="25" border="0" alt="user area" /></a></td>
<td rowspan="2"><a href="/help/" onMouseOut="MM_swapImgRestore();MM_startTimeout()" onMouseOver="MM_showMenu(window.mm_menu_0821133514_5,0,25,null,'ePrints_banner_r5_c11');MM_swapImage('ePrints_banner_r5_c11','','/images/eprints/ePrints_banner_r5_c11_f2.gif',1);"><img name="ePrints_banner_r5_c11" src="/images/eprints/ePrints_banner_r5_c11.gif" width="69" height="25" border="0" alt="Help" /></a></td>
<td rowspan="3" colspan="4"><img name="ePrints_banner_r5_c12" src="/images/eprints/ePrints_banner_r5_c12.gif" width="98" height="40" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="1" height="1" border="0" alt="" /></td>
</tr>
<tr>
<td rowspan="2"><img name="ePrints_banner_r6_c3" src="/images/eprints/ePrints_banner_r6_c3.gif" width="44" height="39" border="0" alt="ePrints home" /></td>
<td><a href="/" onMouseOut="MM_swapImgRestore()" onMouseOver="MM_swapImage('ePrints_banner_r6_c4','','/images/eprints/ePrints_banner_r6_c4_f2.gif',1);"><img name="ePrints_banner_r6_c4" src="/images/eprints/ePrints_banner_r6_c4.gif" width="105" height="24" border="0" alt="ePrints home" /></a></td>
<td><img src="/images/eprints/spacer.gif" width="1" height="24" border="0" alt="" /></td>
</tr>
<tr>
<td><img name="ePrints_banner_r7_c2" src="/images/eprints/ePrints_banner_r7_c2.gif" width="104" height="15" border="0" alt="" /></td>
<td colspan="8"><img name="ePrints_banner_r7_c4" src="/images/eprints/ePrints_banner_r7_c4.gif" width="517" height="15" border="0" alt="" /></td>
<td><img src="/images/eprints/spacer.gif" width="1" height="15" border="0" alt="" /></td>
</tr>
</table></td>
</tr>
<tr><td><table width="100%" style="font-size: 90%; border: solid 1px #ccc; padding: 3px"><tr>
<td align="left"><a href="http://eprints.utas.edu.au/cgi/users/home">Login</a> | <a href="http://eprints.utas.edu.au/cgi/register">Create Account</a></td>
<td align="right" style="white-space: nowrap">
<form method="get" accept-charset="utf-8" action="http://eprints.utas.edu.au/cgi/search" style="display:inline">
<input class="ep_tm_searchbarbox" size="20" type="text" name="q" />
<input class="ep_tm_searchbarbutton" value="Search" type="submit" name="_action_search" />
<input type="hidden" name="_order" value="bytitle" />
<input type="hidden" name="basic_srchtype" value="ALL" />
<input type="hidden" name="_satisfyall" value="ALL" />
</form>
</td>
</tr></table></td></tr>
<tr>
<td class="toplinks"><!-- InstanceBeginEditable name="content" -->
<div align="center">
<table width="720" class="ep_tm_main"><tr><td align="left">
<h1 class="ep_tm_pagetitle">Hydrothermal Alteration and Volatile Element Halos for the Rosebery K Lens Volcanic-Hosted Massive Sulfide Deposit, Western Tasmania</h1>
<p style="margin-bottom: 1em" class="not_ep_block"><span class="person_name">Large, R.R.</span> and <span class="person_name">Allen, R.L.</span> and <span class="person_name">Blake, M.D.</span> and <span class="person_name">Herrmann, W.</span> (2001) <xhtml:em>Hydrothermal Alteration and Volatile Element Halos for the Rosebery K Lens Volcanic-Hosted Massive Sulfide Deposit, Western Tasmania.</xhtml:em> Economic Geology, 96 (5). pp. 1055-1072. ISSN 0361-0128</p><p style="margin-bottom: 1em" class="not_ep_block"></p><table style="margin-bottom: 1em" class="not_ep_block"><tr><td valign="top" style="text-align:center"><a href="http://eprints.utas.edu.au/1876/1/Large_et_al_2001_ECON_GEOL.pdf"><img alt="[img]" src="http://eprints.utas.edu.au/style/images/fileicons/application_pdf.png" border="0" class="ep_doc_icon" /></a></td><td valign="top"><a href="http://eprints.utas.edu.au/1876/1/Large_et_al_2001_ECON_GEOL.pdf"><span class="ep_document_citation">PDF</span></a> - Full text restricted - Requires a PDF viewer<br />572Kb</td><td><form method="get" accept-charset="utf-8" action="http://eprints.utas.edu.au/cgi/request_doc"><input value="2359" name="docid" accept-charset="utf-8" type="hidden" /><div class=""><input value="Request a copy" name="_action_null" class="ep_form_action_button" onclick="return EPJS_button_pushed( '_action_null' )" type="submit" /> </div></form></td></tr></table><p style="margin-bottom: 1em" class="not_ep_block">Official URL: <a href="http://dx.doi.org/10.2113/96.5.1055">http://dx.doi.org/10.2113/96.5.1055</a></p><div class="not_ep_block"><h2>Abstract</h2><p style="padding-bottom: 16px; text-align: left; margin: 1em auto 0em auto">A detailed study of alteration mineralogy, mineral chemistry, and lithogeochemistry in the host rocks surrounding the A-B and K lenses at the north end of the Rosebery mine has revealed a series of overlapping alteration halos with characteristic mineralogy and geochemistry. The study involved logging and sampling from
nine drill holes spaced at varying distances from the A-B and K lenses. The stratiform Zn-Pb-Cu ore lenses
have a sheetlike morphology and are hosted by a mixed sequence of rhyolitic to dacitic massive mediumgrained
quartz-porphyritic pumice breccia, black mudstone, and crystal-rich volcaniclastic sandstone, overlying
a thick homogeneous sequence of rhyolitic pumice breccia.
The major alteration minerals at Rosebery are arranged in a complex series of zones passing away from the
deposit-quartz-sericite zone, Mn carbonate zone, chlorite zone, and outer sericite zone. The chlorite zone is
best developed in the immediate footwall below the copper-pyrite-rich ore lenses, whereas the strongest Mn
carbonate alteration occurs in the immediate hanging-wall volcanics or lateral to the ore lenses. The outermost
visible sericitic alteration extends about 60 to 100 m into the footwall, 10 to 20 m into the hanging wall, and
over 500 m along the upper contact of the footwall pumice breccias.
Thallium and antimony form the most extensive trace element halos related to the mineralization. Thallium
forms a halo that extends 200 to 300 m into the overlying volcanics and 60 to 100 m into the footwall. Anomalously
high thallium also occurs over 500 m along strike marking the contact between the footwall pumice breccias and the overlying volcaniclastic sandstones. Proximal to the ore lenses Tl and Sb values range from 10 to 100 ppm, compared to the halo zone where they vary from around 1 to 10 ppm.
Studies of alteration mineral chemistry at Rosebery have revealed some important relationships that may assist
exploration. The Mn content of alteration carbonate increases toward ore, both along strike and across
strike. Close to ore, alteration carbonates contain >20 mole percent MnCO3 (kutnahorite, rhodochrosite, Mn
siderite, and Mn ankerite), whereas at distances of 40 to 60 m across strike the mole percent MnCO3 in carbonate
drops to below 10 percent. At greater than 80 m, the carbonates are Mn-poor calcites and are commonly
located in synmetamorphic structures. White mica composition changes with stratigraphy and alteration
assemblages and may be related to the mineralizing event, although this has not been convincingly demonstrated.
Proximal white mica contains minor Ba substituting for octahedral Al. However, except for their Ba content, these phengetic white micas are similar to those found in nonmineralized areas of the Mount Read
Volcanics. Sodic white mica with up to 0.35 Na/(Na + K) and a low phengite content (<0.5 Fe + Mg cations)
occurs in a zone of volcanic sandstones and black slates overlying the ore deposit.
This research has lead to the development of a series of proximal, medial, and distal vectors useful for both
regional and mine-scale exploration. The most useful vectors, listed from proximal to distal, include Zn, Ba content
of white mica, Na2O, K2O, Ishikawa alteration index (AI), S/Na2O, Ba/Sr, Mn content of carbonate, Tl, and
Sb.</p></div><table style="margin-bottom: 1em" border="0" cellpadding="3" class="not_ep_block"><tr><th valign="top" class="ep_row">Item Type:</th><td valign="top" class="ep_row">Article</td></tr><tr><th valign="top" class="ep_row">Keywords:</th><td valign="top" class="ep_row">VHMS, Thallium, alteration index, Mt Read Volcanics, manganese, hydrothermal alteration, carbonate alteration, chlorite</td></tr><tr><th valign="top" class="ep_row">Subjects:</th><td valign="top" class="ep_row"><a href="http://eprints.utas.edu.au/view/subjects/260100.html">260000 Earth Sciences > 260100 Geology</a></td></tr><tr><th valign="top" class="ep_row">Collections:</th><td valign="top" class="ep_row">UNSPECIFIED</td></tr><tr><th valign="top" class="ep_row">ID Code:</th><td valign="top" class="ep_row">1876</td></tr><tr><th valign="top" class="ep_row">Deposited By:</th><td valign="top" class="ep_row"><span class="ep_name_citation"><span class="person_name">Mrs Katrina Keep</span></span></td></tr><tr><th valign="top" class="ep_row">Deposited On:</th><td valign="top" class="ep_row">05 Sep 2007</td></tr><tr><th valign="top" class="ep_row">Last Modified:</th><td valign="top" class="ep_row">23 Jan 2008 16:11</td></tr><tr><th valign="top" class="ep_row">ePrint Statistics:</th><td valign="top" class="ep_row"><a target="ePrintStats" href="/es/index.php?action=show_detail_eprint;id=1876;">View statistics for this ePrint</a></td></tr></table><p align="right">Repository Staff Only: <a href="http://eprints.utas.edu.au/cgi/users/home?screen=EPrint::View&eprintid=1876">item control page</a></p>
</td></tr></table>
</div>
<!-- InstanceEndEditable --></td>
</tr>
<tr>
<td><!-- #BeginLibraryItem "/Library/footer_eprints.lbi" -->
<table width="795" border="0" align="left" cellpadding="0" class="footer">
<tr valign="top">
<td colspan="2"><div align="center"><a href="http://www.utas.edu.au">UTAS home</a> | <a href="http://www.utas.edu.au/library/">Library home</a> | <a href="/">ePrints home</a> | <a href="/contact.html">contact</a> | <a href="/information.html">about</a> | <a href="/view/">browse</a> | <a href="/perl/search/simple">search</a> | <a href="/perl/register">register</a> | <a href="/perl/users/home">user area</a> | <a href="/help/">help</a></div><br /></td>
</tr>
<tr><td colspan="2"><p><img src="/images/eprints/footerline.gif" width="100%" height="4" /></p></td></tr>
<tr valign="top">
<td width="68%" class="footer">Authorised by the University Librarian<br />
© University of Tasmania ABN 30 764 374 782<br />
<a href="http://www.utas.edu.au/cricos/">CRICOS Provider Code 00586B</a> | <a href="http://www.utas.edu.au/copyright/copyright_disclaimers.html">Copyright & Disclaimers</a> | <a href="http://www.utas.edu.au/accessibility/index.html">Accessibility</a> | <a href="http://eprints.utas.edu.au/feedback/">Site Feedback</a> </td>
<td width="32%"><div align="right">
<p align="right" class="NoPrint"><a href="http://www.utas.edu.au/"><img src="http://www.utas.edu.au/shared/logos/unioftasstrip.gif" alt="University of Tasmania Home Page" width="260" height="16" border="0" align="right" /></a></p>
<p align="right" class="NoPrint"><a href="http://www.utas.edu.au/"><br />
</a></p>
</div></td>
</tr>
<tr valign="top">
<td><p> </p></td>
<td><div align="right"><span class="NoPrint"><a href="http://www.eprints.org/software/"><img src="/images/eprintslogo.gif" alt="ePrints logo" width="77" height="29" border="0" align="bottom" /></a></span></div></td>
</tr>
</table>
<!-- #EndLibraryItem -->
<div align="center"></div></td>
</tr>
</table>
</body>
</html>
