TY - JOUR

T1 - Geological Position, Sources, and Age of Mingling Dikes of the Northwestern Margin of the Tuva–Mongolian Massif in Western Sangilen, Southeastern Tuva

AU - Yakovlev, V. A.

AU - Karmysheva, I. V.

AU - Vladimirov, V. G.

AU - Semenova, D. V.

N1 - The study was carried out under the state order of the V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences (Nos. 122041400176-0, 122041400171-5).

PY - 2024/2

Y1 - 2024/2

N2 - The best source of information about the specific features of magmatism in collision zones is the late collisional tectono-magmatic stage, which is associated with the largest volume and diversity of the resulting magmatic associations. In this paper, granit-oid and mafic late collisional magmatism is considered using the example of Early Caledonian igneous complexes of Western Sangilen (Tuva–Mongolian massif). Results of geochronological, petrographic, petrogeochemical, and mineralogical studies of the rocks of the Saizyral mingling dike and salic dikes are presented. Approximately ~485 Ma, high-potassium granitoid massifs formed simultaneously with the intrusion and occurrence of a complex of granitoid and mingling dikes. The Saizyral mingling dike resulted from the joint intrusion and mixing of basic and silicic magmas in a low-pressure region within the Erzin shear zone at a middle crust depth level. Interaction of contrasting magmas is comprised of two stages. The first stage occurs during the transport of a contrast mixture and comes down to intensive mechanical mixing and the introduction of LIL and HFS elements, as well as Th and U from granitoids into the mafic rocks. This changes the geochemical characteristics of the mafic rocks. The second stage is when the joint crystallization of magmas is accompanied by gravitational sedimentation of denser mafic magmas and the formation of narrow zones of intermediate composition at the contact of contrasting rocks.

AB - The best source of information about the specific features of magmatism in collision zones is the late collisional tectono-magmatic stage, which is associated with the largest volume and diversity of the resulting magmatic associations. In this paper, granit-oid and mafic late collisional magmatism is considered using the example of Early Caledonian igneous complexes of Western Sangilen (Tuva–Mongolian massif). Results of geochronological, petrographic, petrogeochemical, and mineralogical studies of the rocks of the Saizyral mingling dike and salic dikes are presented. Approximately ~485 Ma, high-potassium granitoid massifs formed simultaneously with the intrusion and occurrence of a complex of granitoid and mingling dikes. The Saizyral mingling dike resulted from the joint intrusion and mixing of basic and silicic magmas in a low-pressure region within the Erzin shear zone at a middle crust depth level. Interaction of contrasting magmas is comprised of two stages. The first stage occurs during the transport of a contrast mixture and comes down to intensive mechanical mixing and the introduction of LIL and HFS elements, as well as Th and U from granitoids into the mafic rocks. This changes the geochemical characteristics of the mafic rocks. The second stage is when the joint crystallization of magmas is accompanied by gravitational sedimentation of denser mafic magmas and the formation of narrow zones of intermediate composition at the contact of contrasting rocks.

KW - CAOB

KW - Nb-rich magmas

KW - Tuva–Mongolian massif

KW - U–Pb dating

KW - collision magmatism

KW - dikes

KW - mingling

KW - mixing

KW - tectonic settings

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85184702962&origin=inward&txGid=1ce8ae12103fa6813f487ec3424d8a68

UR - https://www.webofscience.com/wos/woscc/full-record/WOS:001198936600002

UR - https://www.mendeley.com/catalogue/917112c0-332c-3fbe-a51c-e8f8dd48a5a5/

U2 - 10.2113/RGG20234589

DO - 10.2113/RGG20234589

M3 - Article

VL - 65

SP - 214

EP - 232

JO - Russian Geology and Geophysics

JF - Russian Geology and Geophysics

SN - 1068-7971

IS - 2

ER -