TY - JOUR

T1 - The Ulantovsky granitoid pluton: A new age stage of potentially productive Early Devonian magmatism at Salair

AU - Svetlitskaya, Tatyana V.

AU - Nevolko, Peter A.

AU - Dranishnikova, Daria E.

N1 - The study is done on state assignment of IGM SB RAS (№ 122041400237-8). Публикация для корректировки.

PY - 2023

Y1 - 2023

N2 - Porphyry-type deposits have historically contributed less than 5% to the country's copper reserves in the Russian Federation. However, with the discovery of the Malmyzh and Peschanka deposits, porphyry targets now account for 17% of the nation's total copper reserves. Increasing copper potential through the discovery of new porphyry deposits, both within the previously known porphyry belts and in new regions, is of strategic importance for ensuring and reproducing Russia's mineral resource base. One of these new regions is the Salair Range, where, since 2021, the Ulantovsky granitoid pluton has been a prospecting target for porphyry copper-molybdenum mineralization. The Ulantovsky granitoid pluton is located in the northwestern part of the Salair Range, 118 km southeast of the city of Novosibirsk, and hosts the Verkh-Chemskoe and Ulantovsky Сu-Mo occurrences. The current regional legend indicates that it is a composite pluton consisting of the early (diorite, quartz diorite, tonalite, plagiogranite, and rare gabbro) intrusive phase of the Middle-Late Carboniferous Vydrikhinsky Complex and the late (granite, leucogranite, rare quartz‐syenite and monzodiorite) intrusive phase of the Late Permian-Early Triassic Zhernovsky Complex. However, the available dating results indicate that the granitoids comprising the pluton are Silurian in age. The escalation of prospecting triggered a study of the geological structure and mineral potential assessment of the Ulantovsky pluton. The study presents new high-precision U-Pb LA-ICP-MS zircon ages, whole-rock major and trace element data as well as zircon mineral trace element compositions of the Ulantovsky granitoids. The results were used to clarify the geological structure of the pluton and provide better constraints on the timing and duration of the studied granitic magmatism. Additionally, the capability of granitoids of different intrusive phases to generate viable Cu-Mo-porphyry mineralization was examined using a combination of geological, geochemical, and geochronological studies. The obtained results reveal a Late Silurian to Early Devonian (dated at ca. 426–412 Ma using U-Pb methods) age for the Ulantovsky composite pluton. The pluton consists of the Late Silurian main-phase high-K calc-alkaline leucogranites (ca. 426 Ma) intruded by a series of nearly coeval Early Devonian calc-alkaline pulses of monzonites (ca. 417 Ma), granodiorites (ca. 418 Ma), and plagiogranites (ca. 412 Ma), as well as dikes of monzonites (ca. 414 Ma). New U-Pb zircon ages indicate that the studied granitic suites do not belong to either the Vydrikhinsky or the Zhernovsky complexes as to their age contained in the regional legend. The Early Devonian granitic intrusions of the Ulantovsky pluton reveal a new, not previously securely confirmed, age stage of Paleozoic magmatic activity at Salair. Among all examined igneous suites, plagiogranites of the latest intrusive phase (ca. 412 Ma) originated from hydrous (wholerock Sr/Y = 77–89 and (Sr/Y)/Y = 8.9-12.7; zircon Yb/Dy = avg. 5.6), oxidized (whole-rock V/Sc = 7.7–9.6 > (V/Sc)calc = 5.7– 5.8; zircon Eu/Eu* = avg. 0.44 and ΔFMQ = avg. + 1.2) magmas that evolved through deep-level amphibole fractionation processes (whole-rock Eu/Eu* = avg. 1.2, 10000*(Eu/Eu*)/Y = 1163–2015, and 100*[(Rb/Sr)/FeO*] = 0.64–0.79). They show distinctive whole-rock geochemical and zircon chemical signatures of fertile porphyry suites, suggesting a genetic link between the plagiogranite intrusion and copper-molybdenum mineralization in the Ulantovsky pluton.

AB - Porphyry-type deposits have historically contributed less than 5% to the country's copper reserves in the Russian Federation. However, with the discovery of the Malmyzh and Peschanka deposits, porphyry targets now account for 17% of the nation's total copper reserves. Increasing copper potential through the discovery of new porphyry deposits, both within the previously known porphyry belts and in new regions, is of strategic importance for ensuring and reproducing Russia's mineral resource base. One of these new regions is the Salair Range, where, since 2021, the Ulantovsky granitoid pluton has been a prospecting target for porphyry copper-molybdenum mineralization. The Ulantovsky granitoid pluton is located in the northwestern part of the Salair Range, 118 km southeast of the city of Novosibirsk, and hosts the Verkh-Chemskoe and Ulantovsky Сu-Mo occurrences. The current regional legend indicates that it is a composite pluton consisting of the early (diorite, quartz diorite, tonalite, plagiogranite, and rare gabbro) intrusive phase of the Middle-Late Carboniferous Vydrikhinsky Complex and the late (granite, leucogranite, rare quartz‐syenite and monzodiorite) intrusive phase of the Late Permian-Early Triassic Zhernovsky Complex. However, the available dating results indicate that the granitoids comprising the pluton are Silurian in age. The escalation of prospecting triggered a study of the geological structure and mineral potential assessment of the Ulantovsky pluton. The study presents new high-precision U-Pb LA-ICP-MS zircon ages, whole-rock major and trace element data as well as zircon mineral trace element compositions of the Ulantovsky granitoids. The results were used to clarify the geological structure of the pluton and provide better constraints on the timing and duration of the studied granitic magmatism. Additionally, the capability of granitoids of different intrusive phases to generate viable Cu-Mo-porphyry mineralization was examined using a combination of geological, geochemical, and geochronological studies. The obtained results reveal a Late Silurian to Early Devonian (dated at ca. 426–412 Ma using U-Pb methods) age for the Ulantovsky composite pluton. The pluton consists of the Late Silurian main-phase high-K calc-alkaline leucogranites (ca. 426 Ma) intruded by a series of nearly coeval Early Devonian calc-alkaline pulses of monzonites (ca. 417 Ma), granodiorites (ca. 418 Ma), and plagiogranites (ca. 412 Ma), as well as dikes of monzonites (ca. 414 Ma). New U-Pb zircon ages indicate that the studied granitic suites do not belong to either the Vydrikhinsky or the Zhernovsky complexes as to their age contained in the regional legend. The Early Devonian granitic intrusions of the Ulantovsky pluton reveal a new, not previously securely confirmed, age stage of Paleozoic magmatic activity at Salair. Among all examined igneous suites, plagiogranites of the latest intrusive phase (ca. 412 Ma) originated from hydrous (wholerock Sr/Y = 77–89 and (Sr/Y)/Y = 8.9-12.7; zircon Yb/Dy = avg. 5.6), oxidized (whole-rock V/Sc = 7.7–9.6 > (V/Sc)calc = 5.7– 5.8; zircon Eu/Eu* = avg. 0.44 and ΔFMQ = avg. + 1.2) magmas that evolved through deep-level amphibole fractionation processes (whole-rock Eu/Eu* = avg. 1.2, 10000*(Eu/Eu*)/Y = 1163–2015, and 100*[(Rb/Sr)/FeO*] = 0.64–0.79). They show distinctive whole-rock geochemical and zircon chemical signatures of fertile porphyry suites, suggesting a genetic link between the plagiogranite intrusion and copper-molybdenum mineralization in the Ulantovsky pluton.

KW - Salair Range

KW - U-Pb dating

KW - Ulantovsky pluton

KW - granitoids

KW - porphyry mineralization

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85185507745&origin=inward&txGid=bb36cbb6f68fc56273348f5ae5495f10

UR - https://elibrary.ru/item.asp?id=60210355

UR - https://www.mendeley.com/catalogue/8b67bc5c-81a8-3c95-8762-d31e30e85d1f/

U2 - 10.17223/25421379/29/2

DO - 10.17223/25421379/29/2

M3 - Article

VL - 2023

SP - 21

EP - 48

JO - Геосферные исследования

JF - Геосферные исследования

SN - 2542-1379

IS - 4

M1 - 2

ER -