Andradite–Morimotoite Garnets as Promising U–Pb Geochronometers for Dating Ultrabasic Alkaline Rocks

U–Pb geochronological studies of garnet of the andradite–morimotoite series and Sm–Nd geochronological studies of this garnet and apatite from the Chikskii Massif (Tuva-Mongolia microcontinent) were carried out. The garnet studied is characterized by relatively high concentrations of U (14–16 ppm) a...

Full description

Saved in:
Bibliographic Details
Published in:Doklady earth sciences 2018-06, Vol.480 (2), p.778-782
Main Authors: Salnikova, E. B., Stifeeva, M. V., Nikiforov, A. V., Yarmolyuk, V. V., Kotov, A. B., Anisimova, I. V., Sugorakova, A. M., Vrublevskii, V. V.
Format: Article
Language:English
Subjects:
Apatite
Calcium ferrous silicates
Chronology
Dating
Earth and Environmental Science
Earth Sciences
Garnet
Garnets
Geochemistry
Geochronology
Lead
Low level
Phosphate minerals
Polybutylene terephthalates
Probability theory
Radiometric dating
Rock
Rocks
Uranium
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:U–Pb geochronological studies of garnet of the andradite–morimotoite series and Sm–Nd geochronological studies of this garnet and apatite from the Chikskii Massif (Tuva-Mongolia microcontinent) were carried out. The garnet studied is characterized by relatively high concentrations of U (14–16 ppm) and by a low level of common Pb (Pb с /Pb t = 0.07–0.1). The concordia age of garnet is 492 ± 2 Ma (MSWD = 0.01, probability 92%) and matches within the error with the Sm–Nd age determined by the isochrone for apatite, garnet, and bulk rock (489 ± 9 Ma, MSWD = 0.86). This allows us to consider calcic garnets of the andradite–morimotoite series as promising mineral geochronometers for U–Pb dating of ultrabasic alkaline rocks.
ISSN:1028-334X
1531-8354
DOI:10.1134/S1028334X18060168