Subduction-controlled temporal and spatial variations in early Palaeozoic sedimentary and volcanic record of the Mongol-Altai Domain

Paleozoic Geodynamics and Architecture of the Southern Part of the Mongolian Altai Zone

“…The latter event is manifested by partial melting connected to crustal‐scale extension (Figure 16c) related to renewed oceanic rollback (e.g., Jiang et al., 2016, 2019). This event is accompanied by the development of important Devonian terrigenous and carbonates sedimentation described in the Gobi‐Altai and Hovd domains (Buriánek et al., 2022), and possibly also in the Ulgii domain.…”

“…However, the age of these rocks has not been defined isotopically, and in some places even represent underlying Lake Zone Neoproterozoic to Cambrian ophiolite rocks imbricated with the Mongolian Altai Zone sequences, as is the case of the Hovd domain (Soejono et al., 2017). It has since been argued that the Ordovician siliciclastic sediments of the Zuunuruu formation were deposited either on a hyperextended Precambrian continental margin and the Lake Zone ophiolite, or on a newly formed fore arc oceanic crust (Buriánek et al., 2022).…”

“…Alternatively, the Mongolian Altai Zone has also been tectonically divided by Tomurtogoo (2017) into five terranes which are, from north to south: the Tsagaanshuvuut, Hovd, Ulgii, Tavanbogd, and Bodonch‐Tseel zones (Figure 1, lower left inset). While the Hovd and Tavanbogd zones are dominated mainly by Cambrian and Ordovician siliciclastic sequences, the Ulgii zone is characterized by Devonian terrigenic‐carbonate sediments similar to those of the Gichigene formation of the Gobi‐Altai terrane (Buriánek et al., 2022). In this study, the target domain comprises a junction of four main litho‐stratigraphy zones: the Ulgii and Hovd zones in the west, the Gobi‐Altai terrane in the east (Badarch et al., 2002), and the high‐grade Bodonch‐Tseel zone in the south (Tomurtogoo, 2017).…”

“…Simultaneously, fore‐arc volcanic‐sedimentary sequences were deposited in both the Mongolian and Chinese Altai zones (Jiang et al., 2017; Soejono et al., 2018). This sedimentary evolution was terminated by the deposition of Silurian‐Devonian back‐arc and passive margin sequences (Buriánek et al., 2022). Subsequently, the Devonian–early Carboniferous arcs and back‐arcs formed in the Trans‐Altai Zone in Mongolia and the East Junggar domain in NW China (Nguyen et al., 2018; Xiao et al., 2009).…”

“…(2002) and Tomurtogoo (2017), we prefer to use the term “domain” in this article, instead of the overused terms “terrane” or “zone.” The Hovd domain stratigraphy is defined by Cambrian basic and felsic volcanics, Ordovician and Silurian sandstones, shales, and graywackes intercalated with basic volcanics, and Devonian graywackes, conglomerates, and fossiliferous limestones intercalated with basaltic lavas (Buriánek et al., 2022; Soejono et al., 2018). The Gobi‐Altai domain consists of Upper Cambrian graywackes, shales, quartz sandstones, and abundant basic tuffs and volcanics, Ordovician graywackes, sandstones, and fossiliferous shales and limestones intercalated with basaltic and felsic volcanics, Silurian fossiliferous shales, sandstones, conglomerates, and limestone, and Devonian graywackes, conglomerates, and fossiliferous shale and limestone beds of variable thickness associated with basic volcanism (Buriánek et al., 2022; Lehmann et al., 2010; Rauzer et al., 1987). Apart from the Upper Cambrian sequences, which are metamorphosed at greenschist‐facies conditions, the Ordovician to Devonian strata are not metamorphosed at either the northern or southern flanks of the Altai range.…”