J 2020

Trace Elements in Apatite as Genetic Indicators of the Evate Apatite-Magnetite Deposit, NE Mozambique

SLOBODNÍK, Marek, Veronika DILLINGEROVÁ, Michaela BLAŽEKOVÁ, Monika HURAIOVÁ, Vratislav HURAI et. al.

Základní údaje

Originální název

Trace Elements in Apatite as Genetic Indicators of the Evate Apatite-Magnetite Deposit, NE Mozambique

Autoři

SLOBODNÍK, Marek (203 Česká republika, garant, domácí), Veronika DILLINGEROVÁ (703 Slovensko, domácí), Michaela BLAŽEKOVÁ, Monika HURAIOVÁ a Vratislav HURAI

Vydání

Minerals, Basel, MDPI, 2020, 2075-163X

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10504 Mineralogy

Stát vydavatele

Švýcarsko

Utajení

není předmětem státního či obchodního tajemství

Odkazy

Impakt faktor

Impact factor: 2.644

Kód RIV

RIV/00216224:14310/20:00117589

Organizační jednotka

Přírodovědecká fakulta

UT WoS

000602332600001

Klíčová slova anglicky

apatite; carbonatite; cathodoluminescence; geochemistry; Evate; Mozambique

Štítky

Příznaky

Mezinárodní význam, Recenzováno
Změněno: 14. 7. 2021 13:19, doc. RNDr. Marek Slobodník, CSc.

Anotace

V originále

The Evate deposit is a Neoproterozoic (~590 Ma) magnetite-apatite-carbonate body emplaced parallel to foliation of the Monapo granulite complex in NE Mozambique. A complicated history of the deposit is recorded in apatite textures visualized in cathodoluminescence (CL) images. In spite of different solid and fluid inclusions, mineral assemblages, and the CL textures, electron probe microanalyses indicate relatively consistent apatite compositions corresponding to fluorapatite (XF = 0.51–0.73, XOH = 0.21–0.47, XCl = 0.02–0.06) with limited belovite- and cesanite-type substitutions. Laser ablation inductively coupled plasma mass spectrometric analyses show that apatites from unaltered magnetite-forsterite-spinel ores are depleted in Y, REE, Ba, and Sr compared to apatites from carbonate-anhydrite ores. Hydrothermally overprinted apatites with complex patchy domain CL textures are enriched in Y-REE in greenish-grey zones, Fe-U-Th in blue zones, and Mn-Sr-Ba in brown domains. Observed CL-emissions in the Evate apatites result from very subtle variations in REE, Mn, and U contents controlled by the variability of redox conditions. The decreased Th:U ratio in the hydrothermally overprinted apatites reflects the oxidation and partial removal of U4+ from the apatite structure during the interaction with oxidizing aqueous fluids capable of transporting U6+. Flat, LREE (La-Sm)-enriched chondrite-normalized patterns with Eu/Eu* = 0.7–1.4 and Ce/Ce* = 0.9–1.5, together with concentrations of diagnostic trace elements (Sr, Mn, Y, REE) are consistent with apatites from magmatic carbonatites and phoscorites. This study corroborates that the Evate deposit is a post-collisional orogenic carbonatite genetically linked with mafic plutonic rocks intruding the Monapo granulite complex after granulite-facies metamorphism, and later overprinted by intensive hydrothermalism. The Evate apatite is peculiar in retaining its pristine magmatic signature despite the extensive hydrothermal-metasomatic alteration accompanied by dissolution-reprecipitation.