从"全球冰川"到"雪球假说"——关于新元古代冰川事件的最新研究

新元古代冰期地层不同于显生宙冰期地层，近年来，一些学者提出了雪球假说，掀起了关于新元古代冰期环境特征与因演化的研究热潮，成为当前地学前沿的一个热门课题。本轮研究的一个突出特点，是它的高度综合性，涉及岩石圈，水圈，大气圈和生物圈，此外还牵攫到天体运行等学科。研究重点有新元古代冰川作用的低纬和低海拔特征。与Rodinia超大陆裂解的关系，冰室效应和温室效应的矛盾运动，海洋封冻的探索，碳酸盐岩岩帽的成因，碳，硫，锶等同位素的峰谷变化的环境含义，冰期地层中铁矿的成因，新元古代冰期的次数争议，雪球理论的数值模拟和冰期环境特征及其变化与生物演化，特别是与早寒武世生物大辐射的关系等。我国南方已成为研究新元古代冰期地层及其与寒武系生物大辐射关系的重要地区之一。

From Global Glaciation to Snowball Earth:Recent Researches on the Neoproterozoic Glaciation Events

The glacial rocks of Neoproterozoic are quite different from those of the Phanerozoic and have attracted attention of many outstanding geoscientists of different fields. In the recent decades, especially in recent years, the 'Snowball Earth' hypothesis aroused even more interests on this topic. The Neoproterozoic glacial environments and the causes of the glaciations have now become a hot topic in earth science. The recent researches are characterized by the high comprehensiveness, which is related to studies on litho , hydro , atmo , and the biosphere, and even to the astronomy. Recent studies are mainly focused on the low altitude and low latitude glaciation of the Neoproterozoic, the effect of the breakup of supercontinent Rodinia, the counter relation between the icehouse and the warmhouse effects, the possibility of the complete covering of the oceans by kilometer thick ice, causes of the formation of the cap carbonates, environmental significance of carbon, sulfur, and strontium isotopes, formation of ironstone within the glacial deposition, ages of the Neoproterozoic ice, numerical simulation of the snowball earth theory, and the relationships between the variation of glacial environments and the Cambrian bio radiation. The present researches are aimed to a large extent to reveal the characteristics of the glacial environments, and the isotope geochemical and geochemical methods for extracting important environmental information are widely used. However, the traditional studies on paleogeomagnetism and geochronology remain crucial in the reconstruction of the paleo environments. The stratigraphy of the Nanhua Period in South China are attracting attention of more and more geoscientists all over the world and become an important region for the investigation of relation ship between the Neoproterozoic glaciation and the Cambrian Bio radiation.