JIANG Ganqing1, SHI Xiaoying2 & ZHANG Shihong2 1. Department of Geoscience, University of Nevada, Las Vegas, NV89154-4010, USA; 2. School of Earth Science and Resources and the State Key Laboratoryof Geological Processes and Mineral Resources, China University ofGeosciences, Beijing 100083, China

Methane hydrates constitute the largest pool of readily exchangeable carbon at the Earth’s sedimentary carapace and may destabilize, in some cases catastrophically, during times of global-scale warming and/or sea level changes. Given the ex-treme cold during Neoproterozoic ice ages, the af-termath of such events is perhaps amongst the most likely intervals in Earth history to witness a methane hydrate destabilization event. The coincidence of localized but widespread methane seep-like struc-tures and textures, methane-derived isotopic signal, low sulfate concentration, marine barites, and a prominent, short-lived carbon isotope excursion (δ 13C≤?5‰) from the post-Marinoan cap carbonates (~635 Ma) provides strong evidence for a methane hydrate destabilization event during the late Neopro-terozoic postglacial warming and transgression. Methane release from hydrates could cause a posi-tive feedback to global warming and oxidation of methane could result in ocean anoxia and fluctuation of atmospheric oxygen, providing an environmental force for the early animal evolution in the latest Neo-proterozoic. The issues that remain to be clarified for this event include the trigger of methane hydrate de-stabilization, the time of initial methane release, the predicted ocean anoxia event and its relationship with the biological innovation, additional geochemical signals in response to methane release, and the re-gional and global synchrony of cap carbonate pre-cipitation. The Doushantuo cap carbonate in South China provides one of the best examples of its age for a better understanding of these issues.