Mapping of potential rare earth deposits in the Schiel alkaline complex using sentinel-2B multispectral sensor

AbstractTausonites occurring in aegirine potassium feldspar syenite from the Little Murun potassic alkaline complex are characterised by complex growth and resorption features. These are attributed to nonequilibrium crystallisation in a dynamic environment characterised by magma mixing and/or volatile degassing. The crystals represent a transported assemblage which has no simple relationship to the magma from which their host rock crystallised. Tausonites exhibit significant normal, reverse and oscillatory compositional zoning with respect to strontium and the rare earth elements. The compositions are unique, ranging from tausonite to strontian cerian loparite, and are unlike those found in strontian perovskites from lamproites and fenites associated with carbonatites.Compositional data are presented for Ba-rich titanates belonging to the hollandite group, Ba(Ti,Fe)5O11 and K2Ti13O27. The titanates, on the basis of textural evidence, are interpreted to have formed by the reaction of K-Ba-rich residual liquids with pre-existing Ti-magnetite, ilmenite and tausonite. The compositions of the titanates are similar to those of primary titanates found in kimberlites and carbonatites.

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Two new rare-earth-rich mineral associations in the Ilímaussaq alkaline complex, South Greenland

Geological Survey of Denmark and Greenland Bulletin ◽

10.34194/ggub.v190.5185 ◽

2001 ◽

pp. 143-144

Author(s):

Igor V. Pekov ◽

Irina A. Ekimenkova

Keyword(s):

Rare Earth ◽

Chemical Compositions ◽

Alkaline Complex ◽

Complex Type ◽

Unit Cell Parameters ◽

Widespread Occurrence ◽

Cell Parameters ◽

Mineral Associations

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Pekov, I. V., & Ekimenkova, I. A. (2001). Two new rare-earth-rich mineral associations in the Ilímaussaq alkaline complex, South Greenland. Geology of Greenland Survey Bulletin, 190, 143-144. https://doi.org/10.34194/ggub.v190.5185 _______________ Two new types of REE-rich mineral associations have been discovered at Kvanefjeld in the northern part of the Ilímaussaq alkaline complex. Type 1 consists of ussingite veins intersecting lujavrite and containing 5–7% nacareniobsite-(Ce) and 2–4% steenstrupine-(Ce); the adjacent altered lujavrite contains up to 10–12% nacareniobsite-(Ce). Type 2 consists of cavernous sodalite-rich veinlets and vugs in lujavrite containing 5–8% vitusite-(Ce). The chemical compositions and unit cell parameters of REE minerals are given. Nacareniobsite-(Ce) and vitusite-(Ce) were considered to be extremely rare minerals in the Ilímaussaq complex. Nacareniobsite-(Ce) is now known to be of more widespread occurrence in some hyper-agpaitic rocks of the Ilímaussaq complex, and vitusite-(Ce) is known to be the precursor of the widespread occurrence of the yellow pseudomorphs termed erikite.

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Petrogenesis and U-Pb zircon dating of Chaitma Alkaline Complex from the southern margin of the Central Indian Tectonic Zone: geodynamic implications

Geological Society London Special Publications ◽

10.1144/sp513-2021-28 ◽

2021 ◽

pp. SP513-2021-28

Author(s):

Satya Narayana Mahapatro ◽

M. L. Renjith ◽

Ranjit Kumar Martha ◽

Rakesh Kumar Patel ◽

Dewashish Upadhyay ◽

...

Keyword(s):

Rare Earth ◽

Rare Earth Elements ◽

Magma Mixing ◽

Central India ◽

Alkaline Complex ◽

Tectonic Zone ◽

Southern Margin ◽

Short Period ◽

Heavy Rare Earth Elements ◽

Central Indian Tectonic Zone

AbstractIn this study, we constrain the petrogenesis and U-Pb zircon age of a newly discovered alkaline complex, christened the Chaitma Alkaline Complex at the southern margin of the Central Indian Tectonic Zone in Central India. The Chaitma Alkaline Complex comprises syenites and gabbro, emplaced coevally and show features consistent with magma mixing. Geochemically, syenites are potassic to ultrapotassic (K2O/Na2O: 0.79-3.42) and contain high Ba (∼800 to 2700 ppm) and Sr (∼1400-3200 ppm). They show enrichment of the light rare earth elements (LREE) relative to the heavy rare earth elements (HREE) (La/Yb: 32-103) and do not display Eu-anomaly. Based on their geochemical signatures such as low MgO (<0.87 wt.%), Ni (8-16 ppm) and Cr (7-44 ppm) contents and prominent Zr-Hf negative anomaly, the syenites are inferred to have been derived by partial melting of a carbonated/metasomatised thickened lower crustal source. The coeval gabbros are undersaturated in silica (41-44 wt.%) with relatively high total alkalis (Na2O+K2O: 3.7-5.1 wt.%), Fe2O3 (17-19 wt.%), P2O5 (3.1-4.9 wt.%), Sr (1600-3400 ppm) and Ba (300-3500 ppm) contents. These have low MgO (<4.8 wt.%), Ni (13-30 ppm) and Cr (18-84 ppm). Their chemistry is interpreted to be the result of interaction with the syenitic magma. These geochemical characters along with high LREE/HREE ratio, negative trough in Nb-Ta, Zr-Hf, Ti, Sr and Rb and positive spike of Pb in spider diagram, and enrichment of LILE over HFSE indicate their derivation from metasomatised subduction modified garnet-peridotite mantle source. Our study indicates that syenites and gabbros of the Chaitma Alkaline Complex were formed from genetically unrelated parental magmas derived from distinct sources. U-Pb dating of zircon yielded magmatic emplacement age of 1626±15 Ma for the syenites. The Chaitma Alkaline Complex was presumably formed during a short period of crustal extension in the midst of a protracted period of continent-continent collision and granulite grade metamorphism (c. 1.71-1.58 Ga) at the southern margin of the Central Indian Tectonic Zone.

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First occurrence of moskvinite-(Y) in the Ilímaussaq alkaline complex, South Greenland – implications for rare-earth element mobility

Mineralogical Magazine ◽

10.1180/minmag.2016.080.047 ◽

2016 ◽

Vol 80 (1) ◽

pp. 31-41 ◽

Cited By ~ 1

Author(s):

Henrik Friis

Keyword(s):

Rare Earth ◽

Rare Earth Element ◽

Inductively Coupled Plasma ◽

Large Scale ◽

Earth Element ◽

Theoretical Calculations ◽

Alkaline Complex ◽

Inductively Coupled ◽

First Occurrence ◽

Plasma Mass Spectrometry

AbstractMoskvinite-(Y), Na2K(Y,REE)Si6O15, is a rare mineral, which until now has only been described from its type locality Dara-i-Pioz, Tajikistan. At Ilímaussaq moskvinite-(Y) was discovered in a drill core from Kvanefjeld, where it occurs as a replacement mineral associated with a mineral belonging to the britholite group. The composition was determined by a combination of electron probe microanalysis and laser ablation inductively coupled plasma mass spectrometry analyses. The empirical formula based on 15 oxygens is Na1.94K0.99(Y0.94Yb0.03Er0.03Dy0.03Ho0.01Gd0.01)∑1.05Si5.98O15. The coexistence of an almost pure Y and a light rare-earth element (REE) mineral is interpreted as fractionation ofREEand Y during the replacement of an earlier formedREEmineral. Theoretical calculations of the observed replacement of feldspathoids by natrolite show that the generated fluid would have pH > 8, which inhibits large scale mobility ofREE. In addition, a K-Fe sulfide member of the chlorbartonite-bartonite group is for the first time observed in Ilímaussaq where it occurs where sodalite is replaced by natrolite and arfvedsonite by aegirine. The sulfide incorporates the S and some of the Cl generated by the alteration of sodalite, whereas the K and Fe originates from the replacement of arfvedsonite by aegirine.

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Rare earth element geochemistry of the Fen alkaline complex, Norway

Contributions to Mineralogy and Petrology ◽

10.1007/bf00401455 ◽

1975 ◽

Vol 52 (4) ◽

pp. 247-259 ◽

Cited By ~ 55

Author(s):

Roger H. Mitchell ◽

Arild O. Brunfelt

Keyword(s):

Rare Earth ◽

Rare Earth Element ◽

Earth Element ◽

Alkaline Complex ◽

Element Geochemistry

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Three Compositional Varieties of Rare-Earth Element Ore: Eudialyte-Group Minerals from the Norra Kärr Alkaline Complex, Southern Sweden

Minerals ◽

10.3390/min3010094 ◽

2013 ◽

Vol 3 (1) ◽

pp. 94-120 ◽

Cited By ~ 31

Author(s):

Axel Sjöqvist ◽

David Cornell ◽

Tom Andersen ◽

Muriel Erambert ◽

Mattias Ek ◽

...

Keyword(s):

Rare Earth ◽

Rare Earth Element ◽

Earth Element ◽

Southern Sweden ◽

Alkaline Complex ◽

Eudialyte Group

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Modification of a rare-earth element deposit by low-temperature partial melting during metamorphic overprinting: Norra Kärr alkaline complex, southern Sweden

Chemical Geology ◽

10.1016/j.chemgeo.2020.119640 ◽

2020 ◽

Vol 545 ◽

pp. 119640 ◽

Cited By ~ 2

Author(s):

Axel S.L. Sjöqvist ◽

Thomas Zack ◽

Denise K. Honn ◽

Ethan F. Baxter

Keyword(s):

Rare Earth ◽

Low Temperature ◽

Partial Melting ◽

Rare Earth Element ◽

Earth Element ◽

Southern Sweden ◽

Alkaline Complex

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Magmatic age of rare-earth element and zirconium mineralisation at the Norra Kärr alkaline complex, southern Sweden, determined by U–Pb and Lu–Hf isotope analyses of metasomatic zircon and eudialyte

Lithos ◽

10.1016/j.lithos.2017.09.023 ◽

2017 ◽

Vol 294-295 ◽

pp. 73-86 ◽

Cited By ~ 5

Author(s):

Axel S.L. Sjöqvist ◽

David H. Cornell ◽

Tom Andersen ◽

Ulf I. Christensson ◽

Johan T. Berg

Keyword(s):

Rare Earth ◽

Rare Earth Element ◽

Earth Element ◽

Hf Isotope ◽

Southern Sweden ◽

Alkaline Complex ◽

Isotope Analyses

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Petrology of syenites from center III of the Coldwell alkaline complex, northwestern Ontario, Canada

Canadian Journal of Earth Sciences ◽

10.1139/e93-014 ◽

1993 ◽

Vol 30 (1) ◽

pp. 145-158 ◽

Cited By ~ 10

Author(s):

Roger H. Mitchell ◽

R. Garth Platt ◽

Jurate Lukosius-Sanders ◽

Maureen Artist-Downey ◽

Shelley Moogk-Pickard

Keyword(s):

Rare Earth ◽

Trace Element ◽

Major Element ◽

Volcanic Rocks ◽

Basalt Magma ◽

Alkaline Complex ◽

Quartz Syenite ◽

Element Abundances ◽

Northwestern Ontario ◽

Single Batch

Center III of the Coldwell alkaline complex consists of metaluminous hypersolvus syenites, which in order of intrusion are magnesiohornblende syenite, contaminated ferro-edenite syenite, ferroedenite syenite, and quartz syenite. Contaminated syenites were formed by the assimilation of coeval basaltic volcanic rocks. The suite as a whole is characterized by the presence of a wide variety of amphiboles ranging in composition from magnesiohornblende through ferroedenite and ferrorichterite to arfvedsonite. Pyroxenes are rare and hedenbergite is present in significant amounts only in quartz syenite. Whole-rock major element data indicate that the majority of the syenites do not represent liquid compositions. The syenites have high contents of Nb, Zr, Th, U, Y, and Ga and have the geochemical character of A-type granitoids. Rare earth and other trace element abundances suggest that the quartz syenites cannot be differentiates of the magma that formed the ferroedenite syenites. All syenites are considered to have originated by the extensive fractional crystallization of mantle-derived basalt magma within the plutonic infrastructure of the complex. The syenite suite does not represent the differentiation products of a single batch of magma. Multiple intrusion, contamination, and brecciation of preexisting syenite plutons have resulted in the complex geological relationships characteristic of center III.

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