Latest Permian–Triassic magmatism of the Taimyr Peninsula: New evidence for a connection to the Siberian Traps large igneous province

Abstract

This study presents new whole rock major and trace element, Sr-Nd isotopic, petrographic, and geochronologic data for seven latest Permian (Changhsingian)–Late Triassic (Carnian) granitoid intrusions of the northwestern and northeastern Taimyr Peninsula in the Russian High Arctic. U-Pb zircon ages, obtained using secondary ion mass spectrometry (SIMS), sensitive high-resolution ion microprobe (SHRIMP), and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), define the crystallization age of the Taimyr intrusions studied as ranging from ca. 253 Ma to 228 Ma, which suggests two magmatic pulses of latest Permian–Early Triassic and Middle–Late Triassic age. Ar-Ar dating of biotite and amphibole indicate rapid cooling of the intrusions studied, but Ar-Ar ages of several samples were reset by secondary heating and hydrothermal activity induced by the Middle–Late Triassic magmatic pulse. Petrographic data distinguish two groups of granites: syenite–monzonites and granites–granodiorites. Sr-Nd isotopic data, obtained from the same intrusions, show a variation of initial (87Sr/86Sr)i ratios between 0.70377 and 0.70607, and εNd(t) values range between –6.9 and 1.2. We propose that the geochemical and isotopic compositions of the Late Permian–Triassic Taimyr granites record the existence of a magma mush zone that was generated by the two pulses of Siberian Traps large igneous province (LIP) magmatism.

A Multi-proxy Provenance Study of Late Carboniferous to Middle Jurassic Sandstones in the Eastern Sverdrup Basin and Its Bearing on Arctic Palaeogeographic Reconstructions

“…The depleted mantle trend is drawn assuming a present-day composition of 176 Lu/ 177 Hf = 0.0384 and 176 Hf/ 177 Hf = 0.28325 [108]. [33]), Carboniferous to Triassic granitoids of the Central Asian Orogenic Belt and Triassic granitoids on Taimyr [137,138]. Data from the Taimyr granitoids are whole-rock εNd(t) data are converted to approximate εHf(t) values using the εNd-εHf terrestrial array relationship of Vervoort et al [103].…”

“…Circa 235-250 Ma granitoids are known from Taimyr [137,138] and are a possible source for the largest U-Pb age group in these samples. Whole-rock Nd isotope data from these granitoids, when converted to approximate εHf (t) values, overlap well with the εHf (t) values of c. 235-250 Ma zircons in Late Triassic samples from the Sverdrup Basin (Figure 12b).…”

“…Analyses with U-Pb ages >10% discordant are not shown. (B) U-Pb age versus εHf(t) scatter plot showing data from Late Triassic strata of the Sverdrup Basin (this study and[33]), Carboniferous to Triassic granitoids of the Central Asian Orogenic Belt and Triassic granitoids on Taimyr[137,138]. Data from the Taimyr granitoids are whole-rock εNd(t) data are converted to approximate εHf(t) values using the εNd-εHf terrestrial array relationship of Vervoort et al[103].…”

Provenance of the Mesozoic Succession of Franz Josef Land (North‐Eastern Barents Sea): Paleogeographic and Tectonic Implications for the High Arctic

“…Furthermore, a subordinate population of ZHe ages support an exhumation event across the provenance area during the Carboniferous. In addition, the only viable source of Latest Permian—Triassic zircons is from the Taimyr region, where coeval in age (ca 255–225 Ma) voluminous magmatism have been reported (Kurapov, Ershova, Khudoley, Luchitskaya, Stockli, et al., 2021; Vernikovsky et al., 2003). The youngest detrital zircon age population in the Mesozoic clastics of FJL displays similar ages to those of sedimentation, especially for Upper Triassic–Lower Jurassic sandstones, suggesting the existence of coeval magmatic activity.…”

Arctic Tectonics and Volcanism: a multi-scale, multidisciplinary educational approach

“…In addition to the default files shipped with GPlates, the students were provided with an Arctic dataset bundle (Senger and Shephard, 2023) which included vector and raster data specific to the Arctic and published in peer-reviewed articles by the wider Arctic community. The data includes regional gravity and magnetics and derivatives (Saltus et al, 2011; Gaina et al, 2011), crustal thickness maps (Lebedeva-Ivanova et al, 2019), seismic tomography models (Schaeffer and Lebedev, 2013;Ritsema et al, 2011) andbathymetry (Jakobsson et al, 2012). The students were taught about Euler and finite rotations, how to view and display plate reconstructions and related data including spreading rates and motion paths, how to change frames of reference (absolute and relative), import and export data and images, and make animations of tectonic motions through time.…”