scholarly journals Petrography, geochemistry, and geochronology of the Sc-enriched Kiviniemi ferrodiorite intrusion, eastern Finland

2020 ◽  
Vol 55 (8) ◽  
pp. 1561-1580
Author(s):  
Tapio Halkoaho ◽  
Marjaana Ahven ◽  
O. Tapani Rämö ◽  
Janne Hokka ◽  
Hannu Huhma
Keyword(s):  
Potassium Feldspar ◽  
Crustal Material ◽  
Magmatic Evolution ◽  
Nd Isotope ◽  
Mafic Intrusion ◽  
Mafic Intrusions ◽  
Rock Types ◽  
Icp Ms ◽  
Corona Formation ◽  
Granitoid Complex

Abstract The Kiviniemi mafic intrusion, near the eastern margin of the Paleoproterozoic Central Finland Granitoid Complex, is both spatially and temporally associated with post-kinematic Fe-Ti-P-enriched Svecofennian orogenic mafic magmatism. The main rock types in this small (~ 15 ha) intrusion are garnet-bearing fayalite ferrodiorite, leucoferrodiorite, ferromonzodiorite, and pyroxene diorite. The garnet-bearing fayalite ferrodiorite and leucoferrodiorite contain 50–281 ppm Sc, 275–5600 ppm Zr, and 58–189 ppm Y (n = 42), delineating a mineralized deposit some 2.5 ha in extent. Overall, these rocks show an evolved (iron-enriched) tholeiitic character; low values of Ni (< 20–40 ppm), Cr (< 20 ppm), and Cu (< 20–80 ppm); and high contents of Zn (213–700 ppm). The rock-forming minerals in the ferrodioritic rocks are (ferro)hedenbergite, plagioclase (~ An40), ferropargasite and ferroedenite, almandine garnet, and fayalite (Fo1–4). Accessory minerals include zircon, ilmenite, fluorapatite, biotite, pyrite, pyrrhotite, potassium feldspar, grunerite, and clinoferrosilite. Some relict cumulate textures have been preserved, but primary magmatic features have largely been overprinted by strong recrystallization and corona formation. The main carriers of Sc are amphibole, clinopyroxene, and apatite. The remarkably strong enrichment of Sc in ferromagnesian silicates and apatite, rather than in specific Sc-minerals, implies magmatic enrichment. Post-kinematic mafic intrusions in central Finland constitute a bimodal association with co-existing granitoid counterparts. The Kiviniemi mafic intrusion is associated with a coarse megacrystic granite and the two rock type display mingled contacts, indicative of contemporaneity of the two magmas. This conclusion is in accord with the coincident U-Pb zircon ages for the ferrodiorite, at 1857 ± 2 Ma (multigrain ID-TIMS) and the megacrystic granite, at 1860 ± 7 Ma (single-crystal LA-MC-ICP-MS). The initial εNd value of the ferrodiorite and the granite are + 0.1 and − 2.5, respectively. These Nd isotope compositions probably reflect a chondritic mantle source for the ferrodiorite and suggest incorporation of some Archaean crustal material into the granite in the course of magmatic evolution. The resource estimation calculated for Kiviniemi intrusion by using 40 g/t Sc cut off value is 13.4 Mt of rock with an average grade of 162.7 g/t scandium, 1726 g/t zirconium, and 81 g/t yttrium.

Permian lamprophyres from the Western Carpathians: a review

2021 ◽  
pp. SP513-2020-237
Author(s):  
Ján Spišiak ◽  
Lucia Vetráková ◽  
David Chew ◽  
Štefan Ferenc ◽  
Viera Šimonová ◽  
...  
Keyword(s):  
Hydrothermal Fluid ◽  
Mineralogical Composition ◽  
Western Carpathians ◽  
Crustal Material ◽  
Calc Alkaline ◽  
Geochemical Composition ◽  
Nd Isotope ◽  
Icp Ms ◽  
Compositional Variations ◽  
Alkaline Lamprophyres

AbstractCalc-alkaline lamprophyres from the Western Carpathians occur as dykes and sills in the crystalline complexes (predominantly granites and gneisses) of the Tatric Unit. Some of the lamprophyre dykes have been strongly overprinted by tectonism and hydrothermal fluid ingress. They have a similar mineralogical composition, and they are comprised of clinopyroxene, amphibole, biotite and plagioclase. Based on their modal composition, they can be classified as spessartites and kersantites, and based on their geochemical composition, most of them are of calc-alkali type. Lamprophyres from individual core complexes (e.g. the Malá Fatra Mountains and Nízke Tatry Mountains) exhibit variable Nb, Ta and Sr–Nd isotope signatures. These differences are probably due to compositional variations in the mantle source and/or the lower crust at the site of lamprophyre melt generation, or variable incorporation of crustal material. The age of the lamprophyres is Permian (c. 265 Ma) based on U–Pb LA-ICP-MS dating of apatite micro-phenocrysts.

Origin of the Ordovician Mansehra granite in the NW Himalaya, Pakistan: constraints from Sr–Nd isotopic data, zircon U–Pb age and Hf isotopes

2018 ◽  
Vol 481 (1) ◽  
pp. 277-298 ◽  
Author(s):  
Masatsugu Ogasawara ◽  
Mayuko Fukuyama ◽  
Rehanul Haq Siddiqui ◽  
Ye Zhao
Keyword(s):  
Granitic Magma ◽  
Geochemical Data ◽  
Large Contribution ◽  
Crustal Material ◽  
Sr Isotope ◽  
Nw Himalaya ◽  
Nd Isotope ◽  
Isotope Data ◽  
Late Neoproterozoic ◽  
T Values

AbstractThe Mansehra granite in the NW Himalaya is a typical Lesser Himalayan granite. We present here new whole-rock geochemistry, Rb–Sr and Sm–Nd isotope data, together with zircon U–Pb ages and Hf isotope data, for the Mansehra granite. Geochemical data for the granite show typical S-type characteristics. Zircon U–Pb dating yields 206Pb/238U crystallization ages of 483–476 Ma. The zircon grains contain abundant inherited cores and some of these show a clear detrital origin. The 206Pb/238U ages of the inherited cores in the granite cluster in the ranges 889–664, 1862–1595 and 2029 Ma. An age of 664 Ma is considered to be the maximum age of the sedimentary protoliths. Thus the Late Neoproterozoic to Cambrian sedimentary rocks must be the protolith of the Mansehra granitic magma. The initial Sr isotope ratios are high, ranging from 0.7324 to 0.7444, whereas the εNd(t) values range from −9.2 to −8.6, which strongly suggests a large contribution of old crustal material to the protoliths. The two-stage Nd model ages and zircon Hf model ages are Paleoproterozoic, indicating that the protolith sediments were derived from Paleoproterozoic crustal components.

Age and Sources of Metasandstone of the Chiney Subgroup (Udokan Group, Aldan Shield): Results of U–Th–Pb Geochronological (LA–ICP–MS) and Nd Isotope Study

2018 ◽  
Vol 482 (1) ◽  
pp. 1138-1141 ◽  
Author(s):  
V. P. Kovach ◽  
A. B. Kotov ◽  
D. P. Gladkochub ◽  
E. V. Tolmacheva ◽  
S. D. Velikoslavinsky ◽  
...  
Keyword(s):  
Aldan Shield ◽  
Nd Isotope ◽  
Icp Ms ◽  
Isotope Study

scholarly journals Supplemental Material: Identification of ca. 520 Ma mid-ocean-ridge–type ophiolite suite in the inner Cathaysia block, South China: Evidence from shearing-type oceanic plagiogranite

2021 ◽  
Author(s):  
Longming Li
Keyword(s):  
South China ◽  
Nd Isotope ◽  
Icp Ms ◽  
Mid Ocean Ridge ◽  
Ophiolite Suite ◽  
Cathaysia Block ◽  
Ocean Ridge ◽  
Oceanic Plagiogranite ◽  
Felsic Rocks ◽  
Os Isotope

Table S1: Zircon SIMS U-Pb data and d18O values for the meta-felsic rocks from Shitun area, Cathaysia block, South China; Table S2: LA-ICP-MS analysis of trace elements in zircon from the meta-felsic rocks, Shitun area, Cathaysia block, South China; Table S3: Zircon Hf isotope compositions of the meta-felsic rocks from Shitun area, Cathaysia block, South China; Table S4: Major- and trace-element compositions of the serpentinites, meta-ultramafic rocks, and meta-felsic rocks from Shitun area, Cathaysia block, South China; Table S5: Whole-rock Re-Os isotope compositions of the serpentinites from Shitun area, Cathaysia block, South China; and Table S6: Sr-Nd isotope compositions of the meta-ultramafic and meta-felsic rocks from Shitun area, Cathaysia block, South China.

scholarly journals Geochemistry and Sr, Nd isotopic composition of the Hronic Upper Paleozoic basic rocks (Western Carpathians, Slovakia)

2015 ◽  
Vol 66 (1) ◽  
pp. 3-17 ◽  
Author(s):  
Jozef Vozár ◽  
Ján Spišiak ◽  
Anna Vozárová ◽  
Jakub Bazarnik ◽  
Ján Krái
Keyword(s):  
Basaltic Andesite ◽  
Parental Magma ◽  
Crustal Material ◽  
Nd Isotope ◽  
Upper Paleozoic ◽  
Three Samples ◽  
Original Magma ◽  
Basic Rocks ◽  
Nd Isotopic Composition ◽  
Heterogeneous Source

Abstract The paper presents new major and trace element and first Sr-Nd isotope data from selected lavas among the Permian basaltic andesite and basalts of the Hronicum Unit and the dolerite dykes cutting mainly the Pennsylvanian strata. The basic rocks are characterized by small to moderate mg# numbers (30 to 54) and high SiO2 contents (51-57 wt. %). Low values of TiO2 (1.07-1.76 wt. %) span the low-Ti basalts. Ti/Y ratios in the dolerite dykes as well as the basaltic andesite and basalt of the 1st eruption phase are close to the recommended boundary 500 between high-Ti and low-Ti basalts. Ti/Y value from the 2nd eruption phase basalt is higher and inclined to the high-Ti basalts. In spite of this fact, in all studied Hronicum basic rocks Fe2O3* is lower than 12 wt. % and Nb/La ratios (0.3-0.6) are low, which is more characteristic of low-Ti basalts. The basic rocks are characterized by Nb/La ratios (0.56 to 0.33), and negative correlations between Nb/La and SiO2, which point to crustal assimilation and fraction crystallization. The intercept for Sr evolution lines of the 1st intrusive phase basalt is closest to the expected extrusions age (about 290 Ma) with an initial 87Sr/86Sr ratio of about 0.7054. Small differences in calculated values ISr document a partial Sr isotopic heterogeneity source (0.70435-0.70566), or possible contamination of the original magma by crustal material. For Nd analyses of the three samples, the calculated values εCHUR (285 Ma) are positive (from 1.75 to 3.97) for all samples with only subtle variation. Chemical and isotopic data permit us to assume that the parental magma for the Hronicum basic rocks was generated from an enriched heterogeneous source in the subcontinental lithospheric mantle.

scholarly journals Equilibrium crystallization of massif-type anorthosite residual melts: a case study from the 1.64 Ga Ahvenisto complex, Southeastern Finland

2020 ◽  
Vol 175 (9) ◽  
Author(s):  
Riikka Fred ◽  
Aku Heinonen ◽  
Jussi S. Heinonen
Keyword(s):  
Magma Chambers ◽  
Equilibrium Crystallization ◽  
Liquid Line ◽  
Rock Types ◽  
Residual Magma ◽  
Icp Ms ◽  
Mineral Assemblages ◽  
Residual Melt ◽  
Liquid Line Of Descent

Abstract Fe–Ti–P-rich mafic to intermediate rocks (monzodiorites and oxide–apatite–gabbronorites, OAGNs) are found as small intrusions in most AMCG (anorthosite–magnerite–charnokite–granite) suites. The origin of the monzodioritic rocks is still debated, but in many studies, they are presumed to represent residual liquid compositions after fractionation of anorthositic cumulates. In the 1.64 Ga Ahvenisto complex, SE Finland, monzodioritic rocks occur as minor dike-like lenses closely associated with anorthositic rocks. We report new field, petrographic, and geochemical (XRF, ICP-MS, EMPA) data complemented with crystallization modeling (rhyolite-MELTS, MAGFRAC) for the monzodioritic rocks, apatite–oxide–gabbronorite, and olivine-bearing anorthositic rocks of the Ahvenisto complex. The presented evidence suggest that the monzodioritic rocks closely represent melt compositions while the apatite–oxide–gabbronorite and olivine-bearing anorthositic rocks are cumulates. The monzodioritic rocks seem to form a liquid line of descent (LLD) from primitive olivine monzodiorites to more evolved monzodiorites. Petrological modeling suggests that the interpreted LLD closely corresponds to a residual melt trend left after fractional crystallization (FC) and formation of the cumulate anorthositic rocks and minor apatite–oxide–gabbronorite in shallow magma chambers. Consequent equilibrium crystallization (EC) of separate monzodioritic residual magma batches can produce the observed mineral assemblages and the low Mg numbers measured from olivine (Fo25–45) and pyroxenes (En48–63, Mg#cpx 60–69). The monzodioritic rocks and apatite–oxide–gabbronorites show similar petrological and geochemical characteristics to corresponding rock types in other AMCG suites, and the model described in this study could be applicable to them as well.

In Situ U‐Th‐Pb Dating and Sr‐Nd Isotope Analysis of Bastnäsite by LA‐(MC)‐ICP‐MS

2019 ◽  
Vol 43 (4) ◽  
pp. 543-565 ◽  
Author(s):  
Yue‐Heng Yang ◽  
Fu‐Yuan Wu ◽  
Qiu‐Li Li ◽  
Yamirka Rojas‐Agramonte ◽  
Jin‐Hui Yang ◽  
...  
Keyword(s):  
Isotope Analysis ◽  
Nd Isotope ◽  
Icp Ms

LA-Q-ICP-MS apatite U/Pb geochronology using common Pb in plagioclase: Examples from layered mafic intrusions

2017 ◽  
Vol 102 (3) ◽  
pp. 571-579 ◽  
Author(s):  
Cora C. Wohlgemuth-Ueberwasser ◽  
Christian Tegner ◽  
Victoria Pease
Keyword(s):  
Mafic Intrusions ◽  
Icp Ms ◽  
Layered Mafic Intrusions

scholarly journals Supplemental Material: Identification of ca. 520 Ma mid-ocean-ridge–type ophiolite suite in the inner Cathaysia block, South China: Evidence from shearing-type oceanic plagiogranite

2021 ◽  
Author(s):  
Longming Li
Keyword(s):  
South China ◽  
Nd Isotope ◽  
Icp Ms ◽  
Mid Ocean Ridge ◽  
Ophiolite Suite ◽  
Cathaysia Block ◽  
Ocean Ridge ◽  
Oceanic Plagiogranite ◽  
Felsic Rocks ◽  
Os Isotope

Table S1: Zircon SIMS U-Pb data and d18O values for the meta-felsic rocks from Shitun area, Cathaysia block, South China; Table S2: LA-ICP-MS analysis of trace elements in zircon from the meta-felsic rocks, Shitun area, Cathaysia block, South China; Table S3: Zircon Hf isotope compositions of the meta-felsic rocks from Shitun area, Cathaysia block, South China; Table S4: Major- and trace-element compositions of the serpentinites, meta-ultramafic rocks, and meta-felsic rocks from Shitun area, Cathaysia block, South China; Table S5: Whole-rock Re-Os isotope compositions of the serpentinites from Shitun area, Cathaysia block, South China; and Table S6: Sr-Nd isotope compositions of the meta-ultramafic and meta-felsic rocks from Shitun area, Cathaysia block, South China.

scholarly journals Garnet-amphibole miaskites of the Ilmenogorsky miaskite massif (Southern Urals): Mineralogy and geochemistry

LITOSFERA ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 652-667
Author(s):  
A. B. Nemov
Keyword(s):  
Mineral Composition ◽  
Microprobe Analysis ◽  
Southern Urals ◽  
Crustal Material ◽  
Research Subject ◽  
Accessory Minerals ◽  
Low Concentrations ◽  
Garnet Composition ◽  
Icp Ms ◽  
High Concentrations

Research subject. This paper presents original findings about textural-structural, mineralogical, petrological, and geochemical features of the garnet-amphibole miaskites (firstes) of the Ilmenogorsky miaskite massif.Materials and methods. The microprobe analysis of mineral composition was performed using Tescan Vega3 sbu and REMMA202M scanning microscopes equipped with microanalyzers. The content of major, trace and rareearth elements (REE) in rock samples was determined by the methods of AAS and ICP-MS.Results. The garnet-amphibole miaskites under study are characterized by a rare mineral paragenesis, i.e. garnet-amphibole-pyroxene-nepheline-plagioclase. The mafic minerals exhibit a high ferruginosity (f = 70–99), while the accessory minerals have high Al, F and low REE contents. The garnetamphibole miaskites contains high concentrations of Al, Fe3+, Ca, Na, Be, Rb, Mo, Tl and low concentrations of LILE, HFSE, REE and transit elements.Conclusions. According to the garnet composition and its ferruginosity (f = 95– 99), high contents of Al and F in accessory minerals, the prevalence of Fe3+, as well as negative Eu/Eu* and positive Ce/ Ce* anomalies, the garnet-amphibole miaskites under study are assumed to be the product of acid-alkaline metasomatism occurring under the oxidizing conditions of petrogenesis. The low ratios of Cr/V and Ni/Co indicate the immobility of transit elements during metasomatism, and their clarke of concentration corresponds to the content in metaterrigenous and metacarbonate rocks, which suggests crustal substratum for garnet–amphibole miaskites. Garnet-amphibole miaskites are the markers of the interaction of crustal material with deep fluids, which occurred during the stage of shear tectonics development (270–240 Ma) due to the broad permeability of the rocks composing the Ilmenogorsky miaskite massif.

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