caa a22 4500 445390182 CHVBK 20180317143044.0 cr unu---uuuuu 170323e20110101xx s 000 0 eng 10.1007/s00710-010-0130-x doi (NATIONALLICENCE)springer-10.1007/s00710-010-0130-x The composition of garnet in garnet-rich rocks in the southern Proterozoic Curnamona Province, Australia: an indicator of the premetamorphic physicochemical conditions of formation [Elektronische Daten] [Adriana Heimann, Paul Spry, Graham Teale, Colin Conor, Norman Pearson] Garnet-rich rocks occur throughout the Proterozoic southern Curnamona Province, Australia, where they are, in places, spatially related to Broken Hill-type Pb-Zn-Ag deposits. Fine-scale bedding in these rocks, their conformable relationship with enclosing metasedimentary rocks, and their enrichment in Mn and Fe suggest that they are metamorphosed chemical precipitates. They formed on the floor of a 1.69Ga continental rift basin from hydrothermal fluids mixed with seawater and detritus. Garnet in garnet-quartz and garnet-amphibole rocks is generally light rare earth element (LREE) depleted, and has flat heavy REE (HREE) enriched chondrite-normalized REE patterns, and negative Eu anomalies (Eu/Eu* < 1). Garnet in garnet-rich rocks from the giant Broken Hill deposit has similar REE patterns and either positive (Eu/Eu* > 1) or negative Eu anomalies. Manganese- and Mn-Ca-rich, Fe-poor garnets in garnetite, garnet-hedenbergite, and garnet-cummingtonite rocks at Broken Hill have Eu/Eu* > 1, whereas garnet in Mn-poor, Fe-rich quartz garnetite and quartz-garnet-gahnite rocks from Broken Hill, and quartz garnetite from other locations have Eu/Eu* < 1. The REE patterns of garnet and its host rock and interelement correlations among REEs and major element contents in garnet and its host rock indicate that the Eu anomaly in garnet reflects that of its host rock and is related to the major element composition of garnet and its host rock. The value of Eu/Eu* in garnet is related to its Mn, Fe, and Ca content and that of its host rock, and the distribution of REEs among garnet and accessory phases (e.g., feldspar). Positive Eu anomalies reflect high amounts of Eu that was preferentially incorporated into Mn- and Mn-Ca-rich oxides and carbonates in the protolith. In contrast, Eu/Eu* < 1 indicates the preferential discrimination against Eu by Fe-rich, Mn-poor precursor minerals. Precursors to Mn-rich garnets at Broken Hill formed by precipitation from cooler and more oxidized hydrothermal fluids compared to those that formed precursors to Mn-poor, Fe-rich garnet at Broken Hill and the other locations. Garnet from the Broken Hill deposit is enriched in Zn (> 400ppm), Cr (> 140ppm), and Eu (up to 6ppm and positive Eu anomalies), and depleted in Co, Ti, and Y compared to garnet in garnet-rich rocks from other localities. These values, as well as MnO contents  > 15 wt. % and Eu/Eu* > 1 are only found at the Broken Hill deposit and are good indicators of the presence of Broken Hill-type mineralization. Springer-Verlag, 2010 Heimann Adriana Department of Geological and Atmospheric Sciences, Iowa State University, Ames, IA, USA aut Spry Paul Department of Geological and Atmospheric Sciences, Iowa State University, Ames, IA, USA aut Teale Graham Teale & Associates, P.O. Box740, 5006, North Adelaide, South Australia, Australia aut Conor Colin Geological Survey Branch, Primary Industries and Resources South Australia, GPO Box1671, 5001, Adelaide, South Australia, Australia aut Pearson Norman Gemoc Centre, Macquarie University, 2109, New South Wales, Australia aut Mineralogy and Petrology Springer Vienna 101/1-2(2011-01-01), 49-74 0930-0708 101:1-2<49 2011 101 710 https://doi.org/10.1007/s00710-010-0130-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00710-010-0130-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Heimann Adriana Department of Geological and Atmospheric Sciences, Iowa State University, Ames, IA, USA aut NATIONALLICENCE 700 1- Spry Paul Department of Geological and Atmospheric Sciences, Iowa State University, Ames, IA, USA aut NATIONALLICENCE 700 1- Teale Graham Teale & Associates, P.O. Box740, 5006, North Adelaide, South Australia, Australia aut NATIONALLICENCE 700 1- Conor Colin Geological Survey Branch, Primary Industries and Resources South Australia, GPO Box1671, 5001, Adelaide, South Australia, Australia aut NATIONALLICENCE 700 1- Pearson Norman Gemoc Centre, Macquarie University, 2109, New South Wales, Australia aut NATIONALLICENCE 773 0- Mineralogy and Petrology Springer Vienna 101/1-2(2011-01-01), 49-74 0930-0708 101:1-2<49 2011 101 710 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer