Igneous occurrences comprising stratiform volcanic breccia, diatremes, basalt flows and feeders, and dolerite sills exhibit structural relationships with the EdiacaranCambrian boundary strata on the Olenek Uplift (northeastern Siberian Craton). A U-Pb date of 543.9± 0.24 Ma for zircons from the volcaniclastics (Bowring et al., 1993) had been considered as the age of the magmatic complex and used to constraint the Ediacaran-Cambrian boundary. We conducted a multifaceted study of this complex shedding additional light on its classification, petrology, tectonics and emplacement regime. We distinguish between basic and high-potassic rock varieties and attribute this diversity to a syn-emplacement overprint by K⁺-bearing sedimentary brines. All the rocks are co-magmatic, originated from a mantle-derived alkali-basaltic melt, and constitute a single event herein formally described as the Tas-Yuryakh complex. Its parental melt supposedly originated via 1520 % melting of a garnet lherzolite at 6570 km depth due to reaction of a plume with moderately enriched lithospheric mantle at the passive continental margin. These data combined with the geological evidence corroborate an earlier conclusion that the Tas-Yuryakh complex together with the adjacent Kharaulakh occurrence mark a rift structure that existed at 540 Ma in an ocean basin between Siberia and Baltica. The volcanic events took place over > 600 km² in shallow-depth coastal settings over a drowned carstified carbonate platform. The reaction of the hot magma with seawater and underground brines could have released a substantial mass of halogen- and boron-bearing compounds into the water and atmosphere affecting local environment and biota.