Magnetite–apatite intrusions and calc-alkaline magmatism, Camsell River, N.W.T.

1976 ◽  
Vol 13 (2) ◽  
pp. 348-354 ◽  
Author(s):  
J. P. N. Badham ◽  
R. D. Morton
Keyword(s):  
Volcanic Rocks ◽  
Orogenic Belt ◽  
Alkaline Magmatism ◽  
Calc Alkaline ◽  
Immiscible Liquids ◽  
Intermediate Composition ◽  
Andean Type

The Camsell River area comprises a roof pendant of volcanic rocks within an Aphebian (~1800 m.y.) orogenic belt. Magnetite–apatite intrusions and related bodies are common and are closely associated with plutons of intermediate composition. The magnetitic intrusions are interpreted as immiscible liquids that separated from a magma of intermediate composition. The immiscible fractions were predominantly crystalline when they reached their present higher levels, and final emplacement was facilitated by volatile-streaming and fluidization. Their presence in the orogenic belt is taken as further support for the hypothesis that the orogen was of Andean type.

Calc-Alkaline Volcanism and Plutonism from the Great Bear Batholith, N.W.T.

1973 ◽  
Vol 10 (8) ◽  
pp. 1319-1328 ◽  
Author(s):  
J. P. N. Badham
Keyword(s):  
Continental Margin ◽  
Volcanic Rocks ◽  
Orogenic Belt ◽  
Calc Alkaline ◽  
Bay Area ◽  
Alkaline Volcanism ◽  
Andean Type ◽  
Felsic Volcanic ◽  
Orogenic Belts ◽  
Felsic Volcanic Rocks

The Camsell River – Conjuror Bay area is a pendant of Aphebian intermediate and felsic volcanic rocks, lying in a granitic complex, and is part of the Great Bear batholith. This batholith complex has been interpreted as being the orogenic belt of the Coronation geosyncline.Twenty-four analyses of volcanic and plutonic rocks are presented; these show that, in spite of alteration, the rocks can be classified as comagmatic and part of an alkali-rich calc-alkaline suite. The suite is chemically similar to younger suites from continental-margin orogenic belts. These similarities support proposals that the Coronation geosyncline was of Andean type and that the magmas may have been generated by subduction.

Provenance of igneous clasts in conglomerates of the Archaean Timiskaming Group, Kirkland Lake area, Abitibi greenstone belt, Canada

1994 ◽  
Vol 31 (12) ◽  
pp. 1749-1762 ◽  
Author(s):  
Marc I. Legault ◽  
Keiko Hattori
Keyword(s):  
Greenstone Belt ◽  
Volcanic Rocks ◽  
Hydrothermal Activity ◽  
Tholeiitic Basalt ◽  
Coarse Grained ◽  
Alkaline Magmatism ◽  
Lake Area ◽  
Calc Alkaline ◽  
Intrusive Rocks ◽  
Strike Slip Movement

Four types of igneous clasts from Timiskaming conglomerates of the Kirkland Lake area are identified: calc-alkaline porphyry, trachyte (K2O + N2O > 7.25 wt.%), trondhjemite, and tholeiitic basalt. Clasts derived from quartz–carbonate veins and carbonatized porphyries and komatiites indicate CO2-rich hydrothermal activity along the Larder Lake – Cadillac Fault before sedimentation. Calc-alkaline porphyry, the predominant clast, is similar in appearance to feldspar porphyry intrusions widely exposed in the area, but the two are not related. The porphyry clasts are cogenetic with diorite–granodiorite intrusions and volcanic rocks of the greenstone belt. Andesite clasts are only observed near the base of the assemblage, and the ratio of basalt to andesite increases up stratigraphic sections. The change suggests progressive erosion of arc-related volcanic rocks during sedimentation. Composition, texture, and mineralogy of the trondhjemite clasts are consistent with their derivation from the marginal phases of the Round Lake batholith. Intrusive rocks of the Timiskaming Group (coarse-grained holocrystalline syenitic–monzonitic rocks, biotite-bearing feldspar porphyries, and mica-rich lamprophyres) were not observed in the clasts, which suggests sedimentation prior to unroofing of these rocks. Sedimentation of the conglomerates postdated unroofing of underlying plagioclase porphyry (~2685 Ma), but predated unroofing of Timiskaming intrusions. The distribution of alkaline clasts only in proximity to the fault implies that alkaline magmatism was confined along the fault. Derivation of clasts from both sides of the fault and proximity of inferred sources support a pull-apart basin for sedimentation with minor strike-slip movement during and after the sedimentation.

Andean andesites and crustal growth

1981 ◽  
Vol 301 (1461) ◽  
pp. 305-320 ◽  
Keyword(s):  
Fractional Crystallization ◽  
Volcanic Rocks ◽  
Parental Magma ◽  
Alkaline Magmatism ◽  
Chemical Compositions ◽  
Crustal Growth ◽  
Calc Alkaline ◽  
Asthenospheric Mantle ◽  
The Andes ◽  
Variable Extent

Over the last 200 Ma, the ensialic Andean plate margin has been characterized by calc-alkaline magmatism. The early (Mesozoic), activity was dominantly of basaltic volcanism while the Cainozoic volcanism was of intermediate, calc-alkaline character. The restriction of Recent volcanism to parts of the Andes underlain by thick wedges of asthenospheric mantle, and the Sr and Nd isotopic relations, indicate that the calc-alkaline parental magmas are derived from the asthenospheric mantle. There is no unequivocal geochemical and geophysical evidence that continental crust or sediment has contributed to the mantle source for Andean magmatism. The chemical compositions of the calc-alkaline volcanic rocks of the active volcanic zones are controlled by fractional crystallization, whereas O-Sr isotopic relations reflect crustal interaction of mantle-derived parental magma with the sialic basement of the Andes. The variable extent of fractional crystallization, partial melting, and mixing of crustal contaminant are related to the variable thickness and age of crust in the different volcanic provinces. Calc-alkaline magmatism was largely responsible for post-Mesozoic crustal growth in the Andes and would have depleted the underlying mantle unless balanced by circulation within the asthenospheric mantle wedge. In terms of net growth of the South American continent, it is not certain where the balance lies between growth by magmatic addition and shrinking by erosion.

Supplemental Material: Tectonic origin of the Bainaimiao arc terrane in the southern Central Asian orogenic belt: Evidence from sedimentary and magmatic rocks in the Damao region

2020 ◽  
Author(s):  
Hai Zhou ◽  
Guochun Zhao ◽  
et al.
Keyword(s):  
Volcanic Rocks ◽  
Orogenic Belt ◽  
Central Asian Orogenic Belt ◽  
Isotopic Data ◽  
Magmatic Rocks ◽  
Central Asian ◽  
Southern Central ◽  
Samples And Sampling ◽  
Tectonic Origin

Table S1: Summary of the samples and sampling positions in this study (sampling sites are marked in Fig. 3); Table S2: U-Pb age data for zircons of (meta-)sedimentary and volcanic rocks in this study; Table S3: Lu-Hf isotopic data for zircons of (meta-)sedimentary and volcanic rocks in this study.

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