Isotopic and trace element geochemistry of the Seligdar magnesiocarbonatites (South Yakutia, Russia): Insights regarding the mantle evolution beneath the Aldan-Stanovoy shield

Beitrag in einer Fachzeitschrift


Details zur Publikation

Autorinnen und Autoren: Doroshkevich AG, Prokopyev IR, Izokh AE, Klemd R, Ponomarchuk AV, Nikolaeva IV, Vladykin NV
Zeitschrift: Journal of Asian Earth Sciences
Jahr der Veröffentlichung: 2018
Band: 154
Seitenbereich: 354-368
ISSN: 1367-9120
Sprache: Englisch


Abstract

The Paleoproterozoic Seligdar magnesiocarbonatite intrusion of the Aldan-Stanovoy shield in Russia underwent extensive postmagmatic hydrothermal alteration and metamorphic events. This study comprises new isotopic (Sr, Nd, C and O) data, whole-rock major and trace element compositions and trace element characteristics of the major minerals to gain a better understanding of the source and the formation process of the carbonatites. The Seligdar carbonatites have high concentrations of P2O5 (up to 18 wt%) and low concentrations of Na, K, Sr and Ba. The chondrite-normalized REE patterns of these carbonatites display significant enrichments of LREE relative to HREE with an average La/Ybcn ratio of 95. Hydrothermal and metamorphic overprints changed the trace element characteristics of the carbonatites and their minerals. These alteration processes were responsible for Sr loss and the shifting of the Sr isotopic compositions towards more radiogenic values. The altered carbonatites are further characterized by distinct 18O- and 13C-enrichments compared to the primary igneous carbonatites. The alteration most likely resulted from both the percolation of crustal-derived hydrothermal fluids and subsequent metamorphic processes accompanied by interaction with limestone-derived CO2. The narrow range of negative εNd(T) values indicates that the Seligdar carbonatites are dominated by a homogenous enriched mantle source component that was separated from the depleted mantle during the Archean.


FAU-Autorinnen und Autoren / FAU-Herausgeberinnen und Herausgeber

Klemd, Reiner Prof. Dr.
Professur für Geochemie und Lagerstättenkunde


Einrichtungen weiterer Autorinnen und Autoren

Irkutsk State University / Иркутский государственный университет
Novosibirsk State University (NSU)


Zitierweisen

APA:
Doroshkevich, A.G., Prokopyev, I.R., Izokh, A.E., Klemd, R., Ponomarchuk, A.V., Nikolaeva, I.V., & Vladykin, N.V. (2018). Isotopic and trace element geochemistry of the Seligdar magnesiocarbonatites (South Yakutia, Russia): Insights regarding the mantle evolution beneath the Aldan-Stanovoy shield. Journal of Asian Earth Sciences, 154, 354-368. https://dx.doi.org/10.1016/j.jseaes.2017.12.030

MLA:
Doroshkevich, Anna G., et al. "Isotopic and trace element geochemistry of the Seligdar magnesiocarbonatites (South Yakutia, Russia): Insights regarding the mantle evolution beneath the Aldan-Stanovoy shield." Journal of Asian Earth Sciences 154 (2018): 354-368.

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