Work

RELATION BETWEEN δ13С, δ18О AND REE CONTENT IN CARBONATITES OF THE TOMTOR COMPLEX, SAKHA REPUBLIC (YAKUTIA)

Year: 2024

Type: article

Abstract: The paper reports the comprehensive study of phosphorus-rare metal (polymineral) carbonatites (I) and rare metal (ankerite) carbonatites (II) of the Tomtor massif based on ICP-MS, XRF, XRF-SI, SEM methods and isotope determination of C, O and 86Sr/87Sr. With a similar mineral composition, the REE+Y content in carbonatites (I) averages 0.38 wt. %, and in carbonatites (II) it is 1.3 wt. %. The δ18О-δ13С diagram provides the C and O isotopic compositions of carbonatites (I) and (II) as two intersecting trends: (I) carbonates from wells 4041, 6151, 115-117 represent the secondary generation of carbonates derived with the deuterium fluid involved; (II) depicts transformation of carbonate by low-T fluid, with fluid/rock ratio = 5. The study identified an increase in the REE and δ18O contents in carbonatites as the temperature of their formation decreases and enrichment of rocks with REE minerals, associated with REE mobility reduction in the fluid while the temperature is decreasing.

Source: Geodynamics & Tectonophysics

DOI: 10.5800/gt-2024-15-5-0785

Authors: V. A. Ponomarchuk, E. V. Lazareva, S. M. Zhmodik, A. V. Travin, A. V. Tolstov

Institutions: V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences

Language: English

Topic: Geological and Geochemical Analysis

Subfield: Geophysics

Field: Earth and Planetary Sciences

Domain: Physical Sciences

Open Access status: diamond

Funders: Siberian Branch, Russian Academy of Sciences, Russian Science Foundation, Ministry of Science and Higher Education of the Russian Federation

Awards: G3124621178, G4450659652