Postorogenic carbonatites at Eden Lake, Trans-Hudson Orogen (northern Manitoba, Canada): Geological setting, mineralogy and geochemistry

Chakhmouradian, Anton R.; Mumin, A H; Demény, Attila; Elliott, Barrett

doi:10.1016/j.lithos.2007.11.004

Cited by 89 publications

(32 citation statements)

References 67 publications

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“…1.97-1.95 Ga Gabbros, syenogranites and carbonatites in Daqingshan Complex (Wan et al, 2008(Wan et al, , 2013aMa et al, 2012;Liu et al, 2013). The carbonatites have characteristic enrichments in Sr, Ba and REE combined with depletions in HFSE, similar to other carbonatites emplaced in post-collisional settings (Hou et al, 2006;Chakmouradian et al, 2008). This period of magmatism was accompanied by regional ca.…”

Section: Source Components For S-type Granitesmentioning

confidence: 91%

Paleoproterozoic S-type granites in the Helanshan Complex, Khondalite Belt, North China Craton: Implications for rapid sediment recycling during slab break-off

Wei

Wang

et al. 2014

Precambrian Research

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a b s t r a c t S-type granites, typically derived from the rapid recycling of sedimentary rocks, are sometimes accompanied by contemporary mafic magmatism and granulite metamorphism. However, the geodynamic context for such rock suites is often highly disputed, with various model proposed, including back-arc basin opening, lithospheric delamination, mantle plume and continental rifting. The Paleoproterozoic Khondalite Belt in the North China Craton provides an example of synchronous mafic and felsic magmatism that was accompanied by granulite-facies metamorphic events for which the tectonic affinities of these rocks remains unclear. This study integrates in situ zircon Hf-O isotope analyses, whole-rock geochemistry and Nd isotope results for the earliest two-mica granites (ca. 1.95 Ga) in order to provide constraints on the above issues. The granites are strongly peraluminous (A/CNK value >1.1), and characterized by high zircon ␦18 O values of 7.3-10.6‰, corresponding to calculated magmatic ␦ 18 O values of 9.1-12.3‰, similar to those of typical S-type granites. They have relatively high and homogeneous ε Nd (t) values of −1.1 to +0.9 and highly variable zircon ε Hf (t) values ranging from −1.0 to +8.3. In situ zircon Hf-O isotopic compositions indicate that the S-type granites may contain some mantle or juvenile crustal components in addition to a sediment component. Based on the new results and published data, a slab break-off model is proposed to explain the rapid recycling of sedimentary precursors and the generation of the ca. 1.95 Ga S-type granites.

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Section: Source Components For S-type Granitesmentioning

confidence: 91%

Paleoproterozoic S-type granites in the Helanshan Complex, Khondalite Belt, North China Craton: Implications for rapid sediment recycling during slab break-off

Wei

Wang

et al. 2014

Precambrian Research

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“…An example of discrimination diagram that can be used to distinguish texturally similar carbonatites and metasedimentary rocks from collision zones (data from Demény et al 2004;Chakhmouradian et al 2008;Moore et al 2015;Xu et al 2015;Chakhmouradian et al 2015b). Note the similarity of deformation textures in calcite carbonatite from Eden Lake (Canada) and marble from Miaoya (China), shown in the insets BHybrid^carbonate-silicate magmas may evolve to produce Ca-rich liquids (up to 80 wt.% CaCO 3 ) by immiscibility or crystal fractionation, but in either case, will precipitate silicate minerals before reaching the carbonate liquidus (Lee and Wyllie 1998a, p. 500).…”

Section: Figmentioning

confidence: 99%

Calcite and dolomite in intrusive carbonatites. I. Textural variations

2015

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Carbonatites are nominally igneous rocks, whose evolution commonly involves also a variety of postmagmatic processes, including exsolution, subsolidus re-equilibration of igneous mineral assemblages with fluids of different provenance, hydrothermal crystallization, recrystallization and tectonic mobilization. Petrogenetic interpretation of carbonatites and assessment of their mineral potential are impossible without understanding the textural and compositional effects of both magmatic and postmagmatic processes on the principal constituents of these rocks. In the present work, we describe the major (micro)textural characteristics of carbonatitic calcite and dolomite in the context of magma evolution, fluid-rock interaction, or deformation, and provide information on the compositional variation of these minerals and its relation to specific evolutionary processes.

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“…Previous research has relied on fluid inclusion data, mineral chemical evidence and limited textural observations to gain an understanding of carbonatite petrogenesis (e.g. Katz and Keller 1981;Viladkar and Wimmenauer 1992;Costanzo et al 2006;Chakhmouradian et al 2008;Chakrabarty et al 2009). This study documents the texture, cathodoluminescence and mineral chemistry of major rock-forming minerals of the Eppawala carbonatites, Sri Lanka.…”

Section: Introductionmentioning

confidence: 99%

Petrogenesis of the Eppawala carbonatites, Sri Lanka: A cathodoluminescence and electron microprobe study

Pitawala

Lottermoser

2012

Miner Petrol

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Field and petrographic investigations, cathodoluminescence (CL) studies as well as microprobe analyses of major rock-forming minerals were conducted to establish the crystallization processes in the Eppawala carbonatites, Sri Lanka. The well preserved magmatic textures and crystal morphologies combined with the chemistry of apatite, calcite and dolomite indicate two major stages of crystal growth, which were accompanied by dynamic crystallization conditions. Initially, nucleation of apatite, ilmenite and possibly olivine was associated with rapid crystal growth during slow cooling of the carbonatite melt at depth. The heat loss through the roof and crystallization processes induced the development of turbulent convective currents, which in turn prevented further nucleation and growth of crystals and led to the dispersion of these earlier formed crystals within the magma chamber. Then, rapid upward movement of magma along structural weaknesses led to (i) the transport of mineral clusters, (ii) deformation of ilmenite, (iii) fracturing of apatite and (iv) the emplacement of the carbonatite melt as dykes. Here, the conditions were favourable for the simultaneous crystallization of magnetite, calcite and dolomite in a non-turbulent environment. Subsequent subsolidus alteration caused the hydrothermal overprint of the documented mineral assemblages, particularly along grain boundaries. The study demonstrates that detailed textural examinations of carbonatites combined with mineral chemical analyses and CL investigations can reveal the crystallization processes within carbonatite melts.

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Postorogenic carbonatites at Eden Lake, Trans-Hudson Orogen (northern Manitoba, Canada): Geological setting, mineralogy and geochemistry

Cited by 89 publications

References 67 publications

Paleoproterozoic S-type granites in the Helanshan Complex, Khondalite Belt, North China Craton: Implications for rapid sediment recycling during slab break-off

Paleoproterozoic S-type granites in the Helanshan Complex, Khondalite Belt, North China Craton: Implications for rapid sediment recycling during slab break-off

Calcite and dolomite in intrusive carbonatites. I. Textural variations

Petrogenesis of the Eppawala carbonatites, Sri Lanka: A cathodoluminescence and electron microprobe study

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