Post-collisional two-stage magmatism in the East Sarmatian Orogen, East European Craton: evidence from the Olkhovsky ring complex

Abstract

The Olkhovsky ring complex (ORC) is composed of a two-phase magmatic rock association with quartz diorite-quartz monzodiorite-granodiorite suite in the outer ring (OR) and trondhjemite as the inner stock (IS). Zircon U-Pb dating reveals that the rocks of the OR and IS were emplaced at 2070 ± 9 Ma and 2044 ± 13 Ma, respectively. The OR rocks are intermediate and felsic, metaluminous, low to moderate alkali. Both rocks are enriched relative to primitive mantle in Rb, Ba, Sr, K, and depleted in Nb and Ti. The OR quartz diorite and IS trondhjemite are characterized by positive values εNd(T) = 2.2 and 1.6, respectively. The ORC belongs to intermediate I-type granite with nil or weak crustal contamination, whereas the IS trondhjemite shows adakite-like features that were contaminated with components from earlier magmatic pulses. The low degree of contamination of the hypothetical melt, its basaltic-andesite composition, the elevated potassium and magnesium contents, and trace element patterns of whole rock and zircon, suggest garnet-free lower crust or metasomatized mantle wedge as the magma source for the OR, in a post-collisional setting. The mechanism for the inner stock trondhjemite was probably similar, although the magma source was characterized by the presence of garnet with a moderate degree of melting. Supplementary material: Analytical methods and tabulated analytical data are available at https://doi.org/10.6084/m9.figshare.c.3851104 .

The Telychian (early Silurian) oxygenation event in northern Europe: A geochemical and magnetic perspective

“…As can be seen the records available are strongly biased to igneous datasets with limited metasediment data from western Sarmatia and southern Svecofennian basement. Terentiev et al (2016aTerentiev et al ( ,b, 2017Terentiev et al ( , 2018Terentiev et al ( ,2020, Terentiev & Santosh (2016), Terentiev & Savko (2016). South Svecofennian Igneous Åhäll et al (2002), Baginski et al (2001), Dorr et al (2002, Mansfeld (1996), Skridlaitė et al (2003Skridlaitė et al ( , 2007, Soesoo et al (2006), Sundblad et al (1994), Wiszniewska et al (2002Wiszniewska et al ( , 2007.…”

Neoarchean‐Palaeoproterozoic sedimentary basins in the Sarmatian Craton: Global correlations and connections

“…Our study identifies at least two basinsthe Mikhailovsky and Tim-Kryvyi Rih with different sedimentary sequences or which were possibly different parts of a single large basin. Subsequently, as a result of a collision between Sarmatia and Volgo-Uralia the rocks underwent 2.07 Ga metamorphism under greenschist to amphibolite facies (Savko et al, 2018) and postcollisional magmatism of 2.05-2.07 Ga (Savko, Samsonov, Bazikov, & Kozlova, 2014;Savko, Samsonov, Larionov, et al, 2014;Terentiev et al, 2016;Terentiev, Savko, & Santosh, 2018). Sedimentary deposits underwent folding, metamorphism and erosion, and synforms were transformed into linear tectonic structures as represented by Mikhailovka, Tim (Figures 4 and 5 The conglomerates are generally thin (few metres) and are located at different levels of the lower part of Formations (Pokalyuk & Korzhnev, 2016).…”

Палеопротерозойские диориты Троснянского массива Курского блока Сарматии: U-Pb возраст, изотопная систематика и источники расплавов

“…Распад коллизионного орогена спровоцировал мощный постколлизионный магматизм в интервале 2.05-2.07 млрд. лет [1][2][3]5]. Среди широкого разнообразия постколлизионных магматических комплексов в Курском блоке самыми распространенными являются диоритгранодиоритовые интрузии стойло-николаевского комплекса с возрастом 2.05-2.07 млрд.…”

“…лет выражен внедрением в кору огромного объема разнообразных магм, совмещенных в пространстве и времени. Это S-, A-и I типы гранитоидов, диоритов, габброидов, сиенитов и карбонатитов [1][2][3][4][5]. Такое многообразие обусловлено различиями в строении литосферы, в составе и длительности предыстории корового субстрата, температур, глубин и степени плавления и коровой контаминацией.…”