Mineralogy and geochemistry of Proterozoic shoshonitic lamprophyres from the Tennant Creek Inlier, northern territory

Duggan, M. B.; Jaques, A. L.

doi:10.1080/08120099608728254

Cited by 19 publications

(6 citation statements)

References 17 publications

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“…In addition, a large silica gap, and Fe‐ and Ti‐enrichment trends in basalts are not typical of the calc‐alkali series ( Wilson 1989). Calc‐alkaline signatures are widely recognised in north and central Australian Proterozoic mafic rocks ( Zhao & McCulloch 1993; Duggan & Jaques 1996; Taylor 1997), suggesting the process that imposed this signature was widespread.…”

Section: Geochemistry and Petrogenesis Of Igneous Units In The Arnhemmentioning

confidence: 99%

Basement framework and geodynamic evolution of the Palaeoproterozoic superbasins of north‐central Australia: An integrated review of geochemical, geochronological and geophysical data

Scott

Rawlings

Page

et al. 2000

Australian Journal of Earth Sciences

136

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A largely convergent setting is proposed for crustal, tectonic and basin evolution of the intracratonic regions of north-central Australia between 1800 and 1575 Ma. The new geodynamic model contrasts with previous proposals of widespread extension during the Leichhardt, Calvert and Isa intervals. Local transtensional to extensional structures exist, but these are best explained by a combination of flexural, thermal and dynamic processes related to an active southern margin. The development of thick accumulations of sediments (superbasins) is linked geodynamically to interpreted active margin processes (subduction and magmatic arcs) in central Australia. A synthesis of geochemical data from the 1870-1575 Ma igneous units from the Arnhem, McArthur and Mt Isa regions of north-central Australia confirms the intracratonic setting of these units and suggests that a long-lived thermal anomaly was responsible for the generation of both mafic and felsic magmas. The geochemical characteristics suggest the igneous units are derived from the lithospheric mantle and are not typical rift-or plume-related melts. A review of the U-Pb SHRIMP ages for the entire region demonstrates the minimum distribution of correlative igneous rocks was widespread. Exotic populations in the 207 Pb/ 206 Pb isotopic data provide insights into the nature and evolution of the crust throughout northcentral Australia. Archaean inheritance is found to be nearly ubiquitous. The data support the temporal subdivision of north-central Australia into the Leichhardt (1800-1750 Ma), Calvert (1750-1690 Ma) and Isa (1690-1575 Ma) intervals which are marked by superbasins and concomitant episodes of igneous activity. A highly heterogeneous pre-superbasin crust is interpreted from regional, newly processed geophysical data. The cratonic portion of north-central Australia is interpreted to consist of three broad northwest-trending belts or elements that are further distinguished into western, central and eastern geophysically distinct provinces. A map of the superbasin distribution is derived and integrated with structural and stratigraphic data to assess the evolution of the basins and the crust through time. The superbasin successions of north-central Australia are synchronous and widespread, although not necessarily interconnected. The tectonic model incorporates dynamic tilting of the craton during episodes of subduction and transmission of compressive intraplate stresses through the craton during intervening episodes of orogeny. These processes resulted in flexure, strikeslip deformation and a complex thermal structure. These mechanisms account for the subsidence and basin evolution that results in widespread ramp and strike-slip basins. The model also accounts for the thermal history recorded by magmatic events. The proposed geodynamical model provides a unifying crustal evolution scenario for central and northern Australia for approximately 225 million years of the Proterozoic.

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Section: Geochemistry and Petrogenesis Of Igneous Units In The Arnhemmentioning

confidence: 99%

Basement framework and geodynamic evolution of the Palaeoproterozoic superbasins of north‐central Australia: An integrated review of geochemical, geochronological and geophysical data

Scott

Rawlings

Page

et al. 2000

Australian Journal of Earth Sciences

136

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“…Lamprophyres, especially calc-alkaline lamprophyres, are one of the characteristic rock types in an orogenic belt (Turpin et al, 1988;Wyman and Kerrich, 1989a, b;Rock, 1990;Shappard and Taylor, 1992;Shand et al, 1994;Duggan and Jaques, 1996;Madhavan et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

The geochemistry of lamprophyres in the Laowangzhai gold deposits, Yunnan Province, China: Implications for its characteristics of source region.

et al. 2002

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This paper analyzes the lamprophyres from the Laowangzhai gold deposits in Yunnan Province, China, which have close temporal-spatial relations with gold mineralization, for their major elements, trace elements and rare earth elements (REE), as well as their Sr, Nd isotopic compositions and the contents of fixed ammonia (NH 4 +). The analytical results of major elements indicate that the lamprophyres in this region are potassic, calc-alkaline lamprophyres. Their M [Mg/(Mg+Fe 2+)] and the contents of the transition elements reflect that the rocks possess the characteristics of primary magmas. As compared with the mid-ocean ridge basalts (MORB), the lamprophyres in this region are enriched in large ion lithophile elements (LILE) and high field strength elements (HFSE). Their REE distribution patterns are of the LREEenrichment type and their trace element distribution patterns are of the strong incompatible element enrichment type, indicating that the rocks originated from a fertile mantle. As compared with the modern values of the primitive mantle, the lamprophyres in this region have relatively high 87 Sr/ 86 Sr (0.70644~0.70895) and relatively low 143 Nd/ 144 Nd (0.512436~0.512524). The contents of NH 4 + in the rocks (74.34 ppm~468.7 ppm) are obviously higher than those of other types of mantle-source rocks (1 ppm~27 ppm), but lower than those of the carbonaceous country rocks (799.6 ppm~1742 ppm) in the ore field. Various lines of evidence demonstrate that the lamprophyres which possess the above Sr, Nd isotopic signatures and the contents NH 4 + of could not be derived from the magma with MORB characteristics during its ascending, or derived from the magma chamber, which had both been contaminated by crustal materials with high 87 Sr/ 86 Sr, low 143 Nd/ 144 Nd and high contents of NH 4 + , instead, the rocks are the results of partial melting of the fertile mantle. It is the main mechanism of formation of the fertile mantle in this region that metasomatism of the mantle mixed with crustal materials by fluids resultant from dewatering of crustal materials brought into the mantle during subduction and LREE-, LILE-and HFSErich fluids from the deep mantle (including the astrosphere). Many typical cases to show the close temporalspatial relations of lamprophyres with gold mineralization have been reported from a large number of large-and superlarge-sized gold deposits (Rock

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“…Indirect associations between shoshonitic lamprophyres and orogenic gold-antimony deposits have also been documented from the Permian Hillgrove district, New South Wales, Australia (Ashley et al 1994;Ashley and Craw 2004). A similar direct relationship between shoshonitic lamprophyres and orogenic coppergold-bismuth mineralization has been recorded for the Tennant Creek area, although recent 40 Ar/ 39 Ar age dating indicates that the lamprophyres significantly postdate the mineralization (Duggan and Jaques 1996). Based on available geochemical and geochronological data, the widespread spatial association of gold deposits and lamprophyres, worldwide (e.g.…”

Section: Synthesis Of Indirect Associationsmentioning

confidence: 77%

Indirect Associations Between Lamprophyres and Gold-Copper Deposits

Müller

Groves

2015

Potassic Igneous Rocks and Associated Gold-Copper Mineralization

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Mineralogy and geochemistry of Proterozoic shoshonitic lamprophyres from the Tennant Creek Inlier, northern territory

Cited by 19 publications

References 17 publications

Basement framework and geodynamic evolution of the Palaeoproterozoic superbasins of north‐central Australia: An integrated review of geochemical, geochronological and geophysical data

Basement framework and geodynamic evolution of the Palaeoproterozoic superbasins of north‐central Australia: An integrated review of geochemical, geochronological and geophysical data

The geochemistry of lamprophyres in the Laowangzhai gold deposits, Yunnan Province, China: Implications for its characteristics of source region.

Indirect Associations Between Lamprophyres and Gold-Copper Deposits

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