人类的出现、第四纪冰期的来临,被公认为第四纪以来发生的两大事件。用冰期和间冰期来划分我国第四纪地层是著名地质学家李四光教授所开创并致力研究和极力倡导的。目前越来越多的学者运用冰期间冰期,即从气候地层学观点来划分第四系。国内外大量研究资料表明,第四纪开始时,出现全球性冰期寒冷气候。此时堆积物及其所产化石组合,为确定第四系下限提供了可靠证据。第18届国际地质学会议也建议,以晚第三纪以来第一次明显的气候变冷作为划分第四系下限的依据之一。也就是承认第四纪开始是一次寒冷的冰期气候。W.H.Zagwijn(1960,1974)根据孢粉资料,将荷兰的雷 The emergence of mankind, the arrival of the Quaternary ice age, is recognized as the two major events that have occurred since the Quaternary. The use of glacial and interglacial periods to divide the Quaternary strata in China was initiated by Professor Li Siguang, a famous geologist, and devoted himself to research and advocacy. At present, more and more scholars use the glacial ice age, that is, from the perspective of climate stratigraphy division of Quaternary. A large number of domestic and foreign research data show that the beginning of the Quaternary, the global glacial cold climate. At this moment, the deposit and the fossil assemblage produced by it provide reliable evidence for determining the lower limit of Quaternary. The 18th International Geological Conference also suggested that the first significant climatic cooling since the late Tertiary was to be used as one of the bases for the division of the lower limit of the Quaternary system. That is to say that the beginning of the Quaternary was a cold glacial climate. W.H. Zagwijn (1960, 1974) According to the pollen information, the Dutch mine