六合彩开奖结果

聽My research focuses on the Cryogenian period of Earth history, which lasted from 720 to 635 million years ago. During this time, the Earth experienced two long-lived and extreme global glaciations, often referred to as 'Snowball Earth' events, in which ice sheets extended to the tropics and potentially covered the entire globe. The interval between these events saw the deposition of the first massive carbonate reef complexes in Earth's history. These ancient reefs are the focus of my PhD research, the underlying objectives of which will be to establish the timing of reef formation relative to the Snowball Earth events, evaluate microbial and potentially metazoan communities responsible for building the reefs, and to use the reefs to document past seawater chemistry.聽