<!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 - Soldiers Cap Group iron-formations, Mt Isa Inlier, Australia, as windows into the hydrothermal evolution of a base-metal-bearing Proterozoic rift basin</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="Hatton, O.J." name="eprints.creators_name" /> <meta content="Davidson, G.J." name="eprints.creators_name" /> <meta content="owen.hatton@lionore.com.au" name="eprints.creators_id" /> <meta content="Garry.Davidson@utas.edu.au" name="eprints.creators_id" /> <meta content="article" name="eprints.type" /> <meta content="2007-10-10 02:06:41" name="eprints.datestamp" /> <meta content="2008-01-08 15:30:00" name="eprints.lastmod" /> <meta content="show" name="eprints.metadata_visibility" /> <meta content="Soldiers Cap Group iron-formations, Mt Isa Inlier, Australia, as windows into the hydrothermal evolution of a base-metal-bearing Proterozoic rift basin" 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="chemical sediment, garnet quartzite, hydrothermal, iron-formations, mafic magmatism, Mt Isa Inlier, rare-earth elements, rifting, Soldiers Cap Group." name="eprints.keywords" /> <meta content="The definitive version is available at www.blackwell-synergy.com" name="eprints.note" /> <meta content="The Proterozoic Soldiers Cap Group, a product of two major magmatic rift phases separated by clastic sediment deposition, hosts mineralised (e.g. Pegmont Broken Hill-type deposit) and barren iron oxiderich units at three main stratigraphic levels. Evaluation of detailed geological and geochemical features was carried out for one lens of an apatite–garnet-rich, laterally extensive (1.9 km) example, the Weatherly Creek iron-formation, and it was placed in the context of reconnaissance studies of other similar units in the area. Chemical similarities with iron-formations associated with Broken Hill-type Pb–Zn deposit iron-formations are demonstrated here. Concordant contact relationships, mineralogy, geochemical patterns and pre-deformational alteration all indicate that the Soldiers Cap Group ironformations are mainly hydrothermal chemical sediments. Chondrite normalised REE patterns display positive Eu and negative Ce anomalisms, are consistent with components of both high-temperature, reduced, hydrothermal fluid (more than or equal to 250 degrees C) and cool oxidised seawater. Major element data suggest a largely mafic provenance for montmorillonitic clays and other detritus during chemical sedimentation, consistent with westward erosion of Cover Sequence 2 volcanic rocks, rather than local mafic sources. Ni enrichment is most consistent with hydrogenous uptake by Mn-oxides or carbonates. Temperatures inferred from REE data indicate that although they are not strongly enriched, base metals such as Pb and Zn are likely to have been transported and deposited prior to or following iron-formation deposition. Most chemical sedimentation pre-dated emplacement of the major mafic igneous sill complexes present in the upper part of the basin. Heating of deep basinal brines in a regional-scale aquifer by deep-seated mafic magma chambers is inferred to have driven development of hydrothermal fluids. Three major episodes of extension exhausted this aquifer, but were succeeded by a final climactic extensional phase, which produced widespread voluminous mafic volcanism. The lateral extent of the iron-formations requires a depositional setting such as a sea-floor metalliferous sediment blanket or series of brine pools, with iron-formation deposition likely confined to much smaller fault-fed areas surrounded by Fe–Mn–P-anomalous sediments. These relationships indicate that in such settings, major sulfide deposits and their associated chemical sediment marker horizons need not overlie major igneous sequences. Rather, the timing of expulsion of hydrothermal fluid reflects the interplay between deep-seated heating, extension and magmatism." name="eprints.abstract" /> <meta content="2004-02" name="eprints.date" /> <meta content="published" name="eprints.date_type" /> <meta content="Australian Journal of Earth Sciences" name="eprints.publication" /> <meta content="51" name="eprints.volume" /> <meta content="1" name="eprints.number" /> <meta content="85-106" name="eprints.pagerange" /> <meta content="10.1046/j.1400-0952.2003.01047.x" name="eprints.id_number" /> <meta content="TRUE" name="eprints.refereed" /> <meta content="0812-0099" name="eprints.issn" /> <meta content="http://dx.doi.org/10.1046/j.1400-0952.2003.01047.x" name="eprints.official_url" /> <meta content="ARNOLD G. 1983. The Cloncurry Authorities to Prospect. BHP–Utah Development Co. Miscellaneous Report 1117, April 1983. ASHLEY P. M. 1983. Recent Exploration Results from the Monakoff Prospect, Near Cloncurry, Northwest Queensland. 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Proceedings of the 29th International Geological Congress: Resource Geology Special Issue 17 (C), 138–142." name="eprints.referencetext" /> <meta content="Hatton, O.J. and Davidson, G.J. (2004) Soldiers Cap Group iron-formations, Mt Isa Inlier, Australia, as windows into the hydrothermal evolution of a base-metal-bearing Proterozoic rift basin. Australian Journal of Earth Sciences, 51 (1). pp. 85-106. ISSN 0812-0099" name="eprints.citation" /> <meta content="http://eprints.utas.edu.au/2047/1/Hatton.Davidson.AJES.2004.pdf" name="eprints.document_url" /> <link rel="schema.DC" href="http://purl.org/DC/elements/1.0/" /> <meta content="Soldiers Cap Group iron-formations, Mt Isa Inlier, Australia, as windows into the hydrothermal evolution of a base-metal-bearing Proterozoic rift basin" name="DC.title" /> <meta content="Hatton, O.J." name="DC.creator" /> <meta content="Davidson, G.J." name="DC.creator" /> <meta content="260100 Geology" name="DC.subject" /> <meta content="The Proterozoic Soldiers Cap Group, a product of two major magmatic rift phases separated by clastic sediment deposition, hosts mineralised (e.g. Pegmont Broken Hill-type deposit) and barren iron oxiderich units at three main stratigraphic levels. Evaluation of detailed geological and geochemical features was carried out for one lens of an apatite–garnet-rich, laterally extensive (1.9 km) example, the Weatherly Creek iron-formation, and it was placed in the context of reconnaissance studies of other similar units in the area. Chemical similarities with iron-formations associated with Broken Hill-type Pb–Zn deposit iron-formations are demonstrated here. Concordant contact relationships, mineralogy, geochemical patterns and pre-deformational alteration all indicate that the Soldiers Cap Group ironformations are mainly hydrothermal chemical sediments. Chondrite normalised REE patterns display positive Eu and negative Ce anomalisms, are consistent with components of both high-temperature, reduced, hydrothermal fluid (more than or equal to 250 degrees C) and cool oxidised seawater. Major element data suggest a largely mafic provenance for montmorillonitic clays and other detritus during chemical sedimentation, consistent with westward erosion of Cover Sequence 2 volcanic rocks, rather than local mafic sources. Ni enrichment is most consistent with hydrogenous uptake by Mn-oxides or carbonates. Temperatures inferred from REE data indicate that although they are not strongly enriched, base metals such as Pb and Zn are likely to have been transported and deposited prior to or following iron-formation deposition. Most chemical sedimentation pre-dated emplacement of the major mafic igneous sill complexes present in the upper part of the basin. Heating of deep basinal brines in a regional-scale aquifer by deep-seated mafic magma chambers is inferred to have driven development of hydrothermal fluids. Three major episodes of extension exhausted this aquifer, but were succeeded by a final climactic extensional phase, which produced widespread voluminous mafic volcanism. The lateral extent of the iron-formations requires a depositional setting such as a sea-floor metalliferous sediment blanket or series of brine pools, with iron-formation deposition likely confined to much smaller fault-fed areas surrounded by Fe–Mn–P-anomalous sediments. These relationships indicate that in such settings, major sulfide deposits and their associated chemical sediment marker horizons need not overlie major igneous sequences. Rather, the timing of expulsion of hydrothermal fluid reflects the interplay between deep-seated heating, extension and magmatism." name="DC.description" /> <meta content="2004-02" 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/2047/1/Hatton.Davidson.AJES.2004.pdf" name="DC.identifier" /> <meta content="http://dx.doi.org/10.1046/j.1400-0952.2003.01047.x" name="DC.relation" /> <meta content="Hatton, O.J. and Davidson, G.J. (2004) Soldiers Cap Group iron-formations, Mt Isa Inlier, Australia, as windows into the hydrothermal evolution of a base-metal-bearing Proterozoic rift basin. Australian Journal of Earth Sciences, 51 (1). pp. 85-106. 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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">Soldiers Cap Group iron-formations, Mt Isa Inlier, Australia, as windows into the hydrothermal evolution of a base-metal-bearing Proterozoic rift basin</h1> <p style="margin-bottom: 1em" class="not_ep_block"><span class="person_name">Hatton, O.J.</span> and <span class="person_name">Davidson, G.J.</span> (2004) <xhtml:em>Soldiers Cap Group iron-formations, Mt Isa Inlier, Australia, as windows into the hydrothermal evolution of a base-metal-bearing Proterozoic rift basin.</xhtml:em> Australian Journal of Earth Sciences, 51 (1). pp. 85-106. ISSN 0812-0099</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/2047/1/Hatton.Davidson.AJES.2004.pdf"><img alt="[img]" src="http://eprints.utas.edu.au/style/images/fileicons/application_pdf.png" class="ep_doc_icon" border="0" /></a></td><td valign="top"><a href="http://eprints.utas.edu.au/2047/1/Hatton.Davidson.AJES.2004.pdf"><span class="ep_document_citation">PDF</span></a> - Full text restricted - Requires a PDF viewer<br />1841Kb</td><td><form method="get" accept-charset="utf-8" action="http://eprints.utas.edu.au/cgi/request_doc"><input accept-charset="utf-8" value="2583" name="docid" 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/10.1046/j.1400-0952.2003.01047.x">http://dx.doi.org/10.1046/j.1400-0952.2003.01047.x</a></p><div class="not_ep_block"><h2>Abstract</h2><p style="padding-bottom: 16px; text-align: left; margin: 1em auto 0em auto">The Proterozoic Soldiers Cap Group, a product of two major magmatic rift phases separated by clastic sediment deposition, hosts mineralised (e.g. Pegmont Broken Hill-type deposit) and barren iron oxiderich units at three main stratigraphic levels. Evaluation of detailed geological and geochemical features was carried out for one lens of an apatite–garnet-rich, laterally extensive (1.9 km) example, the Weatherly Creek iron-formation, and it was placed in the context of reconnaissance studies of other similar units in the area. Chemical similarities with iron-formations associated with Broken Hill-type Pb–Zn deposit iron-formations are demonstrated here. Concordant contact relationships, mineralogy, geochemical patterns and pre-deformational alteration all indicate that the Soldiers Cap Group ironformations are mainly hydrothermal chemical sediments. Chondrite normalised REE patterns display positive Eu and negative Ce anomalisms, are consistent with components of both high-temperature, reduced, hydrothermal fluid (more than or equal to 250 degrees C) and cool oxidised seawater. Major element data suggest a largely mafic provenance for montmorillonitic clays and other detritus during chemical sedimentation, consistent with westward erosion of Cover Sequence 2 volcanic rocks, rather than local mafic sources. Ni enrichment is most consistent with hydrogenous uptake by Mn-oxides or carbonates. Temperatures inferred from REE data indicate that although they are not strongly enriched, base metals such as Pb and Zn are likely to have been transported and deposited prior to or following iron-formation deposition. Most chemical sedimentation pre-dated emplacement of the major mafic igneous sill complexes present in the upper part of the basin. Heating of deep basinal brines in a regional-scale aquifer by deep-seated mafic magma chambers is inferred to have driven development of hydrothermal fluids. Three major episodes of extension exhausted this aquifer, but were succeeded by a final climactic extensional phase, which produced widespread voluminous mafic volcanism. The lateral extent of the iron-formations requires a depositional setting such as a sea-floor metalliferous sediment blanket or series of brine pools, with iron-formation deposition likely confined to much smaller fault-fed areas surrounded by Fe–Mn–P-anomalous sediments. These relationships indicate that in such settings, major sulfide deposits and their associated chemical sediment marker horizons need not overlie major igneous sequences. Rather, the timing of expulsion of hydrothermal fluid reflects the interplay between deep-seated heating, extension and magmatism.</p></div><table style="margin-bottom: 1em" cellpadding="3" class="not_ep_block" border="0"><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">Additional Information:</th><td valign="top" class="ep_row">The definitive version is available at www.blackwell-synergy.com</td></tr><tr><th valign="top" class="ep_row">Keywords:</th><td valign="top" class="ep_row">chemical sediment, garnet quartzite, hydrothermal, iron-formations, mafic magmatism, Mt Isa Inlier, rare-earth elements, rifting, Soldiers Cap Group.</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">ID Code:</th><td valign="top" class="ep_row">2047</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">10 Oct 2007 13:06</td></tr><tr><th valign="top" class="ep_row">Last Modified:</th><td valign="top" class="ep_row">09 Jan 2008 02:30</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=2047;">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=2047">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>