关键词: 风棱石, 形态特征, 表面结构, 南黄海

Abstract: Since 1991,some researchers have proposed a hypothesis which claims that the continental shelves of China were once desert environment during the low sea-level of the last glacial maxim in the late Pleistocene.One of the most important evidences of the shelf desertization is that many stones have been collected from the seabed of the southern Yellow Sea of China,which was regarded as ventifacts by the hypothesis.In this paper,the shape and surface characteristics of the seabed stones have been carefully analyzed,and the following differences have been found existing obviously between the seabed stones and ventifacts.First,the shapes of the stone are longish and flat.There are no facets on the surface,which are often regarded as fundamental characteristics of small ventifacts(＜ 10 cm).Second,on the surface of the stones,there are no directional arranged flutes and grooves,which are resulted from the wind abrasion,and they often appear on the big ventifacts(＞ 10 cm).Third,the location of the stones is to the south of the seabed relict and loess regions,which are opposite direction to the north wind.According to the hypothesis,the north wind were dominant during the low sea-level of the last glacial maxim,thus the regional changes of grain size of the relict deposits on the shelves should become thinner and thinner from north to south.In a word,it is not suitable that the seabed stones from the southern Yellow Sea were regarded as ventifacts.Moreover,although ventifacts are indicative of intense wind activity,they do not necessarily signify,as they also form in temperate regions along ocean or lake margins,and in periglacial settings.Therefore,ventifacts cannot be taken as diagnosis of desert environment.

Key words: ventifact, geometry feature, surface texture, environmental significance