Research output: Contribution to journal › Article › peer-review
Petrological and geochemical characteristics and age of the rocks of the Yllymakh massif (Aldan Shield, southern Yakutia). / Vasyukova, E. A.; Ponomarchuk, A. V.; Doroshkevich, A. G.
In: Russian Geology and Geophysics, Vol. 61, No. 4, 01.04.2020, p. 396-411.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Petrological and geochemical characteristics and age of the rocks of the Yllymakh massif (Aldan Shield, southern Yakutia)
AU - Vasyukova, E. A.
AU - Ponomarchuk, A. V.
AU - Doroshkevich, A. G.
PY - 2020/4/1
Y1 - 2020/4/1
N2 - The Yllymakh massif is one of the Mesozoic ring intrusions widespread in Central Aldan. The alkaline rocks composing it are greatly diverse in composition. Based on the obtained petrological, geochemical, and geochronological data, we have recognized three groups of rocks, marking the different phases of the massif formation. The rocks of two groups resulted from the fractionation of rock-forming minerals (pyroxene and plagioclase) and accessory apatite, which is reflected in the composition trends in the variation diagrams and in the REE patterns. Assimilation of the crustal material also significantly contributed to the diversity of rock-forming melts, which is evidenced from the increase in 87Sr/86Sr from group to group. At the same time, the εNd value is steadily extremely low throughout the study area (on average, -13.5). The obtained Ar-Ar geochronological data indicate three independent stages of the massif formation: 140.0 ± 1.9, 130.0 ±1.9-131.0 ± 2.4, and 125.0 ± 1.9 Ma, which are close in time to the evolution stages of other Mesozoic massifs in Aldan.
AB - The Yllymakh massif is one of the Mesozoic ring intrusions widespread in Central Aldan. The alkaline rocks composing it are greatly diverse in composition. Based on the obtained petrological, geochemical, and geochronological data, we have recognized three groups of rocks, marking the different phases of the massif formation. The rocks of two groups resulted from the fractionation of rock-forming minerals (pyroxene and plagioclase) and accessory apatite, which is reflected in the composition trends in the variation diagrams and in the REE patterns. Assimilation of the crustal material also significantly contributed to the diversity of rock-forming melts, which is evidenced from the increase in 87Sr/86Sr from group to group. At the same time, the εNd value is steadily extremely low throughout the study area (on average, -13.5). The obtained Ar-Ar geochronological data indicate three independent stages of the massif formation: 140.0 ± 1.9, 130.0 ±1.9-131.0 ± 2.4, and 125.0 ± 1.9 Ma, which are close in time to the evolution stages of other Mesozoic massifs in Aldan.
KW - Alkaline rocks
KW - Ar-Ar age
KW - Central Aldan
KW - Sr-Nd isotope composition
KW - Yllymakh massif
KW - alkaline rocks
KW - COMPLEX
KW - ND
KW - ENRICHMENT
KW - ISOTOPIC COMPOSITION
KW - GEOCHRONOLOGY
KW - HF
UR - http://www.scopus.com/inward/record.url?scp=85088293940&partnerID=8YFLogxK
U2 - 10.15372/RGG2019147
DO - 10.15372/RGG2019147
M3 - Article
AN - SCOPUS:85088293940
VL - 61
SP - 396
EP - 411
JO - Russian Geology and Geophysics
JF - Russian Geology and Geophysics
SN - 1068-7971
IS - 4
ER -
ID: 24957384