Geochemical features and geodynamic setting of formation of the Lukinda dunite-troctolite-gabbro massif (southeastern framing of the Siberian Platform)
Geochemical features and geodynamic setting of formation of the Lukinda dunite-troctolite-gabbro massif (southeastern framing of the Siberian Platform)
Russian Geology and Geophysics (July 2012) 53 (7): 636-648
- absolute age
- Ar-40/Ar-39
- Ar/Ar
- argon
- Asia
- Commonwealth of Independent States
- dates
- dunite
- gabbros
- geodynamics
- high-field-strength elements
- igneous rocks
- isotope ratios
- isotopes
- Lower Permian
- mafic composition
- metals
- noble gases
- Paleozoic
- peridotites
- Permian
- plutonic rocks
- radioactive isotopes
- rare earths
- Russian Federation
- Siberian Platform
- stable isotopes
- trace elements
- troctolite
- ultramafic composition
- ultramafics
- Lukinda Massif
- Selenga-Stanovoy Terrane
The Lukinda dunite-troctolite-gabbro massif in the Selenga-Stanovoy Superterrane on the southeastern framing of the Siberian Platform was earlier considered Precambrian. The performed (super 40) Ar/ (super 39) Ar dating of the massif plagioclase yielded an Early Permian age (285 + or - 7.5 Ma). The main specific petrochemical features of the intrusion rocks during their crystallization differentiation are an increase in SiO (sub 2) and CaO contents and a decrease in FeO (sub tot) content, with TiO (sub 2) content remaining low and showing minor variations. A specific geochemical feature of the Lukinda Massif ultrabasite-basites is a slight domination of LREE over HREE, with (La/Yb)N = 1.0-8.2. The depletion of the massif rocks in LILE (except for Sr and Ba), REE, and HFSE suggests that the massif formed on an active continental margin.
