Early-Middle Paleozoic volcanic rocks from the Ereendavaa terrane (Tsarigiin gol area, NE Mongolia) with implications for tectonic evolution of the Kherlen massif

The Beginning of a Wilson Cycle in an Accretionary Orogen: The Mongol–Okhotsk Ocean Opened Assisted by a Devonian Mantle Plume

“…Thus, we suggest the basalts from the Mukhar Formation represent initial oceanic crust formation during early seafloor spreading, similar to the scenario of the young South China Sea where extensive E‐MORB occurs along the seafloor (Larsen et al., 2018; Liao et al., 2022). In the Ereendavaa terrane along southern margin of the MOO, coeval bimodal volcanic rocks and alkaline riebeckite granites (418‐409 Ma) document an Early Devonian extensional environment (Narantsetseg et al., 2019; Orolmaa et al., 2015). An extensional environment is also supported by the widespread occurrence of the Devonian diabase and gabbro‐diabase sill swarms within the Early Devonian shallow marine molasse formations in this region (Narantsetseg et al., 2019), which is usually suggested to document continental lithospheric extension, continental rifting and breakup events (e.g., Bryan & Ernst, 2008).…”

“…In the Ereendavaa terrane along southern margin of the MOO, coeval bimodal volcanic rocks and alkaline riebeckite granites (418‐409 Ma) document an Early Devonian extensional environment (Narantsetseg et al., 2019; Orolmaa et al., 2015). An extensional environment is also supported by the widespread occurrence of the Devonian diabase and gabbro‐diabase sill swarms within the Early Devonian shallow marine molasse formations in this region (Narantsetseg et al., 2019), which is usually suggested to document continental lithospheric extension, continental rifting and breakup events (e.g., Bryan & Ernst, 2008). These records of extension are coeval with the Devonian Altay–Sayan LIP, suggesting the ascent of an Early Devonian mantle plume may have triggered the opening of the MOO.…”