Rare-earth element distribution in exhalites associated with Broken Hill-type mineralisation at the Pinnacles deposit, New South Wales, Australia

Metalogenia del depósito de manganeso Santa Rosa, Baja California Sur, México

“…La movilidad del Eu está regida por las condiciones redox, donde un empobrecimiento en Eu indica fluidos hidrotermales oxidados y de baja temperatura, y un enriquecimiento en Eu revela fluidos calientes y reducidos (Parr, 1992). La anomalía negativa de Eu en las menas de Santa Rosa denota fluidos oxidados y de baja temperatura, coincidiendo con una mayor presencia de óxidos de manganeso que de bari-ta, mientras que en Agua Caliente se reportan anomalías ligeramente positivas de Eu (Canet et al, 2005a), indicando fluidos ligeramente reducidos y de moderada temperatura, concordando con una mayor presencia de barita, pirita y cinabrio que de óxidos.…”

Geochemistry of the sediment-hosted disseminated gold deposits in Southwestern Guizhou Province, China /

“…al., 1984;Giere, 1986;Whitford et al, 1988;Lottermoser, 1992;Parr, 1992;Wood and Williams-Jones, 1994;Bierlein, 1995;Bierlein et al, 1999). The mobility of trace elements in altered host-rocks, and their distribution in host rocks and ores may provide constraints regarding the physico-chemical characteristics of the ore-bearing fluids, and may contribute to understanding the ore-forming processes (Lottermoser, 1992).…”

The preservation of pre-metamorphic colloform banding in pyrite from the Broken Hill-type Pinnacles deposit, New South Wales, Australia

“…These micaceous metasediments volumetrically dominate the stratigraphy and exhibit well developed metamorphic fabrics (see below). The sulphide orebodies are interlayered with a suite of garnet-rich (garnetites and quartz-bearing garnetites; Spry and Wonder, 1989) and quartzgahnite meta-exhalites (Parr, 1992a). On the surface, but not in the mine itself, country rocks which are exposed include amphibolites, quartzmagnetite rocks and garnet-magnetite and garnethematite rocks.…”

“…Stratabound base metal sulphide mineralisation is concentrated, although not exclusively located, at the transition from volcanic to sedimentary derived sequences, which is a characteristic of Broken Hill-type mineralisation (Parr and Plimer, 1994). The mineralisation is associated with a suite of chemically unusual rocks such as garnetites, quartz-garnet, quartz-gahnite, quartz-magnetite, magnetite-garnet and tourmaline-quartz rocks all of which have been interpreted as the metamorphic equivalent of exhalites (Stanton, 1972;Barnes, 1980;Lottermoser, 1989;Parr, 1992a). Although alternative tectonic models have been proposed Wright et al, 1987), the overall stratigraphic sequence of the Willyama Supergroup is believed to represent deposition in an evolving intracontinental rift environment which formed as the result of extensional tectonism of young Proterozoic crust Stevens et al, 1988).…”