Permo-Triassic plume magmatism of the Kuznetsk Basin, Central Asia: geology, geochronology, and geochemistry

Abstract

The Kuznetsk Basin is located in the northern part of the Altai–Sayan Folded Area (ASFA), southwestern Siberia. Its Late Permian–Middle Triassic section includes basaltic stratum-like bodies, sills, formed at 250–248 Ma. The basalts are medium-high-Ti tholeiites enriched in La. Compositionally they are close to the Early Triassic basalts of the Syverma Formation in the Siberian Flood basalt large igneous province, basalts of the Urengoi Rift in the West Siberian Basin and to the Triassic basalts of the North-Mongolian rift system. The basalts probably formed in relation to mantle plume activity: they are enriched in light rare-earth elements (LREE; Lan = 90–115, La/Smn = 2.4–2.6) but relatively depleted in Nb (Nb/LaPM = 0.34–0.48). Low to medium differentiation of heavy rare-earth elements (HREE; Gd/Ybn = 1.4–1.7) suggests a spinel facies mantle source for basaltic melts. Our obtained data on the composition and age of the Kuznetsk basalts support the previous idea about their genetic and structural links with the Permian–Triassic continental flood basalts of the Siberian Platform (Siberian Traps) possibly related to the activity of the Siberian superplume which peaked at 252–248 Ma. The abruptly changing thickness of the Kuznetsk Late Permian–Middle Triassic units suggests their formation within an extensional regime similar to the exposed rifts of Southern Urals and northern Mongolia and buried rifts of the West Siberian Basin.

Structural evolution and late Carboniferous magmatism of the Zhongguai arc in the western Junggar Basin, Northwest China: implications for tectonic evolution of the Junggar Ocean

“…Safonova et al 2009;Buslov et al 2010;Li et al 2014b). In the Nb-Y-Ce diagram (Figure 11d), all the felsic rocks fall within the field of A2-type granites, which is usually defined as representing A-type magmas derived from lower crust in a post-collision setting (Eby 1992).…”

Emplacement and exhumation of the Kuznetsk‐Alatau basement (Siberia): implications for the tectonic evolution of the Central Asian Orogenic Belt and sediment supply to the Kuznetsk, Minusa and West Siberian Basins

“…, 2006) (Fig 1). Its sediments are predominantly Permian–Cretaceous (Buslov et al. , 2010; Davies et al.…”

Duration of Granitoid Magmatism in Peripheral Parts of Large Igneous Provinces (Based on 40ar/39ar Isotopic Studies of Altai Permian-Triassic Granitoids)

“…Correlation between the Permian-Triassic magmatism stages estimated for the Siberian platform and the Altai region of the Central Asian Fold Belt. Modified after [Dobretsov et al, 2010;Borisenko et al, 2010;Buslov et al, 2010;Vasyukova et al, 2011;Malitch, Latypov, 2011;Reichow et al, 2009]. See the description of stages 1 to 4 in the text.…”

“…Корреляция возрастных рубежей пермо-триасового магматизма Сибирской платформы и Алтайского секто-ра ЦАСП. Использованы данные [Dobretsov et al, 2010;Borisenko et al, 2010;Buslov et al, 2010;Vasyukova et al, 2011;Malitch, Latypov, 2011;Reichow et al, 2009]. Характеристику стадий I-IV см.…”

“…In the adjacent Kuznetsk basin, there are local occurrences of traps dated 251-248 Ma [Kruk at al., 1999;Buslov et al, 2010;Nastavko et al, 2012]. Granitoid and gabbrogranite intrusions are more abundant.…”