TY - JOUR

T1 - Petrology and Age of the Yamaat Uul Mafic Complex, Khangai Mountains, Western Mongolia

AU - Shelepaev, Roman

AU - Shapovalova, Maria

AU - Egorova, Vera

AU - Shelepov, Yaroslav

AU - Oyunchimeg, Tumen Ulzii

AU - Tolstykh, Nadezhda

N1 - The reported study was funded by Russian Science Foundation, No. 22-77-00058, https://rscf.ru/en/project/22-77-00058/, accessed on 14 June 2023.

PY - 2023/6

Y1 - 2023/6

N2 - The Yamaat Uul mafic complex with Cu-Ni mineralization is located in the Khangai Mountains of Western Mongolia. We have received new unique data for mafic rocks of the complex: U-Pb dating (SHRIMP II), mineralogy (WDS) and geochemistry (XRF, ICP-MS), Sm-Nd and Rb-Sr isotope data and sulphur isotopes. The Yamaat Uul mafic complex consists of two intrusions: Intrusion 1 is represented by rocks of plagioclase cumulates and olivine–pyroxene cumulates; Intrusion 2 consists of monzogabbro. Intrusions 1 and 2 are different in composition of minerals such as olivine, plagioclase and biotite. The monzogabbro has higher contents of incompatible elements (REE, K, Ti, P) than rocks of Intrusion 1. Zircon U-Pb dating of the anorthosite and Bt-Am-Ol gabbronorite shows a Late Permian age (255.8 ± 2.9 Ma and 262.6 ± 3.1 Ma, respectively) for the Yamaat Uul mafic complex. All of the rocks of the complex are derived from a unified parental melt due to different amounts of trapped melts in plagioclase and olivine–pyroxene cumulates and without crustal contamination. The Cu-Ni mineralization of the complex has a low degree of evolution of the sulphide melt, similar to PGE-Cu-Ni mafic–ultramafic intrusions of the Khangai Mountains (Nomgon and Oortsog Uul). The Yamaat Uul mafic complex together with other mafic–ultramafic intrusions of the Khangai Mountains is related to the Khangai LIP and can be considered as potential for the PGE-Cu-Ni. The new geological, petrological, geochemical and isotope–geochronological data can later be used to reconstruct the geotectonics of the Khangai Mountains and the Central Asian orogenic belt as a whole.

AB - The Yamaat Uul mafic complex with Cu-Ni mineralization is located in the Khangai Mountains of Western Mongolia. We have received new unique data for mafic rocks of the complex: U-Pb dating (SHRIMP II), mineralogy (WDS) and geochemistry (XRF, ICP-MS), Sm-Nd and Rb-Sr isotope data and sulphur isotopes. The Yamaat Uul mafic complex consists of two intrusions: Intrusion 1 is represented by rocks of plagioclase cumulates and olivine–pyroxene cumulates; Intrusion 2 consists of monzogabbro. Intrusions 1 and 2 are different in composition of minerals such as olivine, plagioclase and biotite. The monzogabbro has higher contents of incompatible elements (REE, K, Ti, P) than rocks of Intrusion 1. Zircon U-Pb dating of the anorthosite and Bt-Am-Ol gabbronorite shows a Late Permian age (255.8 ± 2.9 Ma and 262.6 ± 3.1 Ma, respectively) for the Yamaat Uul mafic complex. All of the rocks of the complex are derived from a unified parental melt due to different amounts of trapped melts in plagioclase and olivine–pyroxene cumulates and without crustal contamination. The Cu-Ni mineralization of the complex has a low degree of evolution of the sulphide melt, similar to PGE-Cu-Ni mafic–ultramafic intrusions of the Khangai Mountains (Nomgon and Oortsog Uul). The Yamaat Uul mafic complex together with other mafic–ultramafic intrusions of the Khangai Mountains is related to the Khangai LIP and can be considered as potential for the PGE-Cu-Ni. The new geological, petrological, geochemical and isotope–geochronological data can later be used to reconstruct the geotectonics of the Khangai Mountains and the Central Asian orogenic belt as a whole.

KW - Cu-Ni mineralization

KW - Khangai Mountains

KW - LIP

KW - Permian

KW - Sr-Nd isotope

KW - geochemistry

KW - mineralogy

KW - petrology

KW - sulphur

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85163992723&origin=inward&txGid=919008466383f97dce10a2708fedeff0

UR - https://www.mendeley.com/catalogue/1c641a9c-8be9-3b9c-ac0d-0e929c738517/

U2 - 10.3390/min13060833

DO - 10.3390/min13060833

M3 - Article

VL - 13

JO - Minerals

JF - Minerals

SN - 2075-163X

IS - 6

M1 - 833

ER -