Early Cambrian explosive super-eruptions in the north-western margin of Gondwana may have triggered the ‘Strangelove ocean’

Abstract The ‘Strangelove ocean’ (a state of ocean, almost devoid of living organisms) documented in the early Cambrian strata in South China, has been thought to be driven by an extraterrestrial impact, but this viewpoint has been doubted for emerging geochemical evidence. Volcanism may be a trigger for the oceanic crisis. However, such a linkage has not yet been established. Here, we conduct an investigation into the timing and origin of the early Cambrian K-bentonites (a type of clay rock formed from volcanic ash) of the Yangtze and Baoshan blocks. The results suggest that the K-bentonites may represent early Cambrian explosive super-eruptions occurred in the north-western margin of Gondwana. The eruptions might trigger the anoxia of the contemporaneous ocean and coincided temporally with a bio-crisis preceding the summit of the Cambrian explosion. We propose that they may have initiated the ‘Strangelove ocean’ and delayed the climax of the Cambrian bio-radiation.