TY - JOUR

T1 - Conditions of Early Paleozoic Basaltic and Picritic Magmatism in West Siberia

AU - Simonov, V. A.

AU - Kontorovich, V. A.

AU - Kotlyarov, A.

AU - Saraev, S.

AU - Filippov, Yu F.

AU - Stupakov, S.

N1 - Funding Information: Authors thank professor O.M. Turkina (V.S. Sobolev Institute of Geology and Mineralogy), professor A.A. Aris-kin (Lomonosov Moscow State University), and DSc A.Ya. Medvedev (A.P. Vinogradov Institute of Geochemistry) for their comments that helped to improve the quality of the article. The work was carried out on state assignment of V.S. Sobolev Institute of Geology and Mineralogy and Trofimuk Institute of Petroleum Geology and Geophysics, with the support of the Ministry of Science and Higher Education of the Russian Federation, FSR project 0331-2019-0021 and 14.Y26.31.0029 contract, as well as with the support of RFBR and the Administration of the Tomsk Region (project 19-45-700009r_a). Publisher Copyright: © 2020, V.S. Sobolev IGM, Siberian Branch of the RAS.

PY - 2020/11

Y1 - 2020/11

N2 - Geological, petrological, isotope-geochemical (40Ar/39Ar analysis, petrochemical data, and geochemistry of trace elements and REE), and mineralogical researches testify that the formation of the early Paleozoic basalt and picrite complexes of the West Siberian Plate basement was related to the development of the Cambrian subduction zone of the Paleo-Asian Ocean. Using the compositions of clinopyroxenes and amphiboles (and also programs of computational modeling), we have established the Р–Т conditions of formation of early Paleozoic picrite complexes. Crystallization of clinopyroxenes began at significant depths (25–20 km) and at high temperatures (1300–1275 °C). Olivine might have formed at elevated pressures (8–7 kbar) and temperatures of 1540–1490 °C. Amphiboles formed, most likely, at 6.1–4.5 kbar and much lower temperatures, 1105–1060 °C. Petrochemical analysis and data on trace elements and REE in the rocks of the studied early Paleozoic complexes in West Siberia testify to their intricate formation involving magmatic systems with basalt (island arc and back-arc basins), picrite, and shoshonite (and also WPB type) melt characteristics. Taking into account the similar geochemical characteristics of the early Paleozoic basaltoids and picrites of the West Siberian Plate basement and the Kamchatka volcanics, we suggest that a considerable part of the studied ancient complexes formed by the model implying (as in the case of the Sredinnyi Ridge in Kamchatka) the action of enriched magmatic systems during the development of a destructive window (“slab-window”) under rupture of subducted plate on the background of common island arc magmatism.

AB - Geological, petrological, isotope-geochemical (40Ar/39Ar analysis, petrochemical data, and geochemistry of trace elements and REE), and mineralogical researches testify that the formation of the early Paleozoic basalt and picrite complexes of the West Siberian Plate basement was related to the development of the Cambrian subduction zone of the Paleo-Asian Ocean. Using the compositions of clinopyroxenes and amphiboles (and also programs of computational modeling), we have established the Р–Т conditions of formation of early Paleozoic picrite complexes. Crystallization of clinopyroxenes began at significant depths (25–20 km) and at high temperatures (1300–1275 °C). Olivine might have formed at elevated pressures (8–7 kbar) and temperatures of 1540–1490 °C. Amphiboles formed, most likely, at 6.1–4.5 kbar and much lower temperatures, 1105–1060 °C. Petrochemical analysis and data on trace elements and REE in the rocks of the studied early Paleozoic complexes in West Siberia testify to their intricate formation involving magmatic systems with basalt (island arc and back-arc basins), picrite, and shoshonite (and also WPB type) melt characteristics. Taking into account the similar geochemical characteristics of the early Paleozoic basaltoids and picrites of the West Siberian Plate basement and the Kamchatka volcanics, we suggest that a considerable part of the studied ancient complexes formed by the model implying (as in the case of the Sredinnyi Ridge in Kamchatka) the action of enriched magmatic systems during the development of a destructive window (“slab-window”) under rupture of subducted plate on the background of common island arc magmatism.

KW - basalt and picrite complexes

KW - West Siberian Plate basement

KW - Ar-40/Ar-39 analysis

KW - petrochemistry and geochemistry

KW - P-T parameters of magmatism

KW - clinopyroxene

KW - amphibole

KW - PHYSICOCHEMICAL PARAMETERS

KW - EXPERIMENTAL CALIBRATION

KW - OCEANIC PLATEAU

KW - GEOCHEMISTRY

KW - MANTLE

KW - PETROGENESIS

KW - EVOLUTION

KW - SYSTEMS

KW - LAVAS

KW - BASIN

KW - Ar/ Ar analysis

KW - P–T parameters of magmatism

UR - http://www.scopus.com/inward/record.url?scp=85135760541&partnerID=8YFLogxK

U2 - 10.15372/RGG2019171

DO - 10.15372/RGG2019171

M3 - Article

VL - 61

SP - 1212

EP - 1230

JO - Russian Geology and Geophysics

JF - Russian Geology and Geophysics

SN - 1068-7971

IS - 11

ER -