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Early Mesoproterozoic bimodal plutonism in the southeastern Gawler Craton, South Australia

Both, R. A.; Raymond, Oliver L.; Purvis, Alan Charles; Fanning, C. M.; Zang, W. L.
Fonte: Taylor and Francis Publicador: Taylor and Francis
Tipo: Artigo de Revista Científica
Publicado em //2007 EN
Relevância na Pesquisa
37.64%
The Curramulka Gabbronorite on Yorke Peninsula, southeastern Gawler Craton has an emplacement age of 1589 ± 5 Ma. This is similar to previously determined ages for Arthurton Granite (1582 ± 7 Ma), Tickera Granite (ca 1600 - 1575 Ma), regional alteration, the Moonta - Wallaroo mineralisation (ca 1585 Ma) and localised deformation (Tiparra Deformation). Mesoproterozoic bimodal plutonism is interpreted to have resulted from mafic underplating, emplacement of mafic magmas during lithospheric attenuation and enhanced high heat flow assisting in melting of the lower crust to form the broadly A-type Arthurton and Tickera Granites. Plutonism either directly or indirectly created advective fluid-flow to form Cu - Au mineralisation in the Moonta - Wallaroo area. The nature and characteristics of Mesoproterozoic mafic bodies on the Gawler Craton are poorly known. The Curramulka Gabbronorite has a continental tholeiitic composition and igneous layering that is partly of cumulus origin but also contains magmatic segregations formed by fractionation. Some of these segregations have provided zircons for dating. This igneous layering is overprinted by two foliations of tectonic origin: the first is interpreted to be coeval with magma emplacement and the second with conjugate shearing accompanied by retrogression.; W. L. Zang...

Some aspects of the structural control of the copper lodes at the Wheal Hughes and Poona mines, Moonta, South Australia

Mendis, D. P. J.
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //1992 EN
Relevância na Pesquisa
37.24%
A study has been made of the structural fabrics, including foliations and fractures, of the copper deposits in the Wheal Hughes and Poona mines located at Moonta, South Australia. A working model with two major phases of evolution is hence suggested. Emplacement of copper rich magmatic hydrothermal solutions into the fractures of the Moonta Porphyry is suggested to be the first major phase. Conjugate shearing coupled with faulting is suggested to be the second major phase. The resultant shear movements of the second phase appear to have affected the early formed mineralization (050 azimuth, moderately dipping to the NW at Poona Mine) localising the ore mainly into en-echelon boudins and necking zones as well as along tectonic breccias (050 azimuth, moderate to steep dipping to the SE). A series of faults perpendicular to the shear planes of the second phase smear out the ore up to hundreds of metres and appears to have occurred just after the shearing, before complete cooling.; Thesis (B.Sc.(Hons)) -- University of Adelaide, School of Earth and Environmental Sciences, 1992; This item is only available electronically.

Origin and controls of deposition of the Wheal Hughes and Poona copper deposits, Moonta, South Australia

Hafer, M. R.
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //1991 EN
Relevância na Pesquisa
38.02%
The Wheal Hughes and Poona mines are situated within the Moonta-Wallaroo copper district on the NW region of Yorke Peninsula approximately 150 km NW of Adelaide, S.A. Copper mineralisation is hosted by the Moonta Porphyry, a rhyolite/rhyodacite feldspar porphyry of Early Proterozoic age. The Wheal Hughes and Poona lodes are structurally controlled tabular, en echelon and sheeted fissure veins, which strike 040-050 and have a 45deg to 60deg westerly dip. Two distinct groups of mineralisation are found to occur at Wheal Hughes: (1) the NE Leighton's lode which closely resembles Poona and is typical of Moonta lodes, and (2) the SW Wheal Hughes lode which is unique to the region, in consisting of a series of parallel veins in close proximity and having extensive wall rock alteration. Mineralisation consists predominantly of chalcopyrite and pyrite with minor components of magnetite, hematite, bornite, marcasite, carrollite, molybdenite and gold. A generic model for the mineralisation at Wheal Hughes and Poona is proposed from fluid inclusion studies and petrographic studies, and sulphur isotope, chlorite and sericite analyses together with thermodynamic modelling. Magmatic hydrothermal fluids enriched in metals migrated towards the surface via fractures...

Analyses of late stage, Mesoproterozoic, syn and post tectonic, magmatic events in the Moonta Sub-domain: Implications for Cu-Au mineralisation in the "Copper Triangle" of South Australia

Wurst, A. T.
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //1994 EN
Relevância na Pesquisa
27.76%
The Moonta-Wallaroo area has been of economic, historical and scientific importance in South Australia's history for over 130 years. The nature of mineralisation in the area has long been a point of conjecture. This study looks at the nature of ore deposition and specifically its relationship to granitoids and pegmatites in the Moonta Subdomain. Using various analytical techniques the study has shown that granitoids in the region have distinctly different petrological, textural, structural, geochemical and isotopic characteristics. Two main granitoids were·recognised as the Tickera Granite and the Arthurton Granite. Geochemical studies suggest that magmatism in the Moonta Subdomain was a continuous process in the Mesoproterozoic. The older Tickera Granite, displays syn-collisional, more I-type characteristics and syn-collisional S-type characteristics (represented by a monzonite and a tonalite respectively). The younger Arthurton Granite shows A-type, anorogenic characteristics. A temporal shift from syn-collisional to anorogenic granites suggests a tectonic control on magma generation and emplacement during this period. Trace element characteristics of the Arthurton Granite are homogeneous over a wide spatial range, is suggesting that it may be part of an extensive batholith. Geochemistry of pegmatites implies that they were late stage fractionation products...

Early Mesoproterozoic bimodal plutonism in the southeastern Gawler Craton, South Australia

Zang, W L; Fanning, Christopher; Purvis, A C; Raymond, Oliver L.; Both, R.A.
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
26.68%
The Curramulka Gabbronorite on Yorke Peninsula, southeastern Gawler Craton has an emplacement age of 1589 ± 5 Ma. This is similar to previously determined ages for Arthurton Granite (1582 ± 7 Ma), Tickera Granite (ca 1600-1575 Ma), regional alteration,