尹赞勋先生对第四纪研究的开拓性贡献──兼论顾乡屯动物群及其时代

顾乡屯动物群是由１９３１年尹赞勋先生在哈尔滨顾乡屯发现１９种哺乳动物化石而得名，其后在东北、内蒙古一带多处发现，由于以被毛犀、猛犸象化石最为常见，一般也称为“披毛犀－猛犸象动物群”。到目前为止该动物群至少有６４种化石，分属１８科３７属。顾乡屯组代表东北地区晚更新世河－湖相沉积，与华北萨拉乌苏组有很好的对比性，属同期异地同相沉积。顾乡屯动物群化石层位仅限于顾乡屯组地表出露部分，年龄测定结果不超过６００００─７００００ａＢ．Ｐ．，表明顾乡屯动物群相当于萨拉乌苏上部动物群，时代为晚更新世晚期。顾乡屯动物群与顾乡屯组在时代上的不一致性，是东北地区第四纪研究中应引起重视的问题。对大同第四纪火山群及我国近期火山的分布，自３０年代由尹赞勋先生做了开创和倡导性研究以来，在岩石学、地球化学、树造环境和深部岩浆源及年代学等方面的研究都已取得长足的进展。

RECOLLECTIONS OF THE OUTSTANDING CONTRIBUTIONS OF PROFESSOR YIN ZANXUN TO THEQUATERNARY RESEARCH: RECOGNITIONS OF THE GUXIANGTUN FAUNAAND ITS AGE

The Guxiangtun Fauna, commonly known as Mammuthus Coelodonta Fauna, wasfirst discovered by Professor Yin Zanxun in 1931. Afterwards, this Fauna has beensuccessively discovered in many places in Northeast China. It seems that the distribution of this Fauna may extend eastward through the Korea to the northern partof Japan, and westward it can be traced to Europe. All these regions belong to thesame faunal province.In the previous work, the Guxiangtun Fauna and the Guxiangtun Formation havegenerally been correlated to the Salausu Fauna and Salausu Formation in North China, their ages were believed to be Late Pleistocene or later.According to the recent relevant studies on the Guxiangtun Fauna, the followingrecognitions can be gained:1. The re-examination of the Guxiangtun Fauna has revealed that it consists of64 species of fossils, which can be assigned to 18 families and 37 genera, respectively. In respect to the composition of fossil assemblage of the fauna discovered invarious localities in Northeast China, they all belong to Guxiangtun Fauna, and nofurther subdivision can be distinguished.2. The thickness of the Guxiangtun Formation in Northeast China region is generally up to 20-50m. The formation, however, has not been exposed completely,and the part exposed onto the surface is only about 10m thick. The discovered fossilbeds are all within this 10m thick exposed stratum. The (14)C age of the lowest partof the profile at the locality where the Guxiangtun Fauna has been named as olderthan 40 000aB.P., and is generally estimated to be less than 60-70 thousands aB.P.In North China, however, as observed at the Dishaogou profile in Wushen Banner,Inner Mongolia, which is the representative locality of the Salausu Formation, the.total thickness of the formation is up to 60m. The (14)C age of the top of the formaxtion is 8 100aB.P., while the thermoluminescent dating of the bottom gets an age of170 thousands aB.P. The fossils were discovered in various horizons from the top tothe bottom of the formation. Therefore, it is unreasonable to correlate generally theGuxiangtun Pauna with the Salausu Fauna. It is possible that the Guxiangtun Faunacorresponds to the upper part of the Salausu Fauna, and the age corresponds to thelate stage of Late Pleistocene.3. As a fluvial-lacustrine sedimentary stratum, the Guxiangtun Formation inNortheast China has a long-standing history of study, and is of representative significance. The formation consists of the exposed about 10m thick stratum, as well asthe buried part of thickness about 10-40m. Therefore, the Guxiangtun and SalausuFormations, which represent the Late Pleistocene stratigraphic unit in Northeast andNorth China, respectively, can be well correlated. They belong to heterochthonousdeposits of the same factes and period. In other words, they represent the Late Pleistocene fluvial-lacustrine strata in Northeast and North China.4. Among the Guxiangtun mammal faunas, it is mammuthus fossils that werefirst discovered in China. According to Li Xingguo, the (14)C ages of the fossils are29 800±1 340aB.P. Mammuthus fossils were widely discovered in Northeast China,and their 14C ages are mostly older than 18 000aB.P. In Siberia, however, the (14)Cages of mammuthus fossils are mostly 11 450±250aB.P. It is inferred, therefore, thatthe mammuthus had migrated to high latitude area before the coldest stage of LatePleistocene.Stone artifacts were discovered in Guxiangtun, while in many localities of North'east China stone artifacts and the traces of ancient man were discovered togetherwith the mammuthus fossils. It is possible, therefore, that human activity had impelled the mammalians to migrate to high latitude area. This phenomenon of mass.extinction or migration caused by human activity, such as hunting, has increasingly'attracted the attention of more and more scientists. Obviously, we should also paygreat attention to this phenomenom that occurred in Quaternary.Since the pioneer and creative works of Professor Yin Zanxun in 1930s on theDatong Quaternary volcanoes and the distribution of r