【摘要】 自1920年以来,在中国黄土高原及邻近地区的黄土及河湖相地层分布区发现了大量的古人类活动遗迹地点,其中包括著名的泥河湾、水洞沟、萨拉乌苏、丁村、大荔、匼河-西侯度、庄浪、庆阳、三门峡、东秦岭地区以及蓝田地区等.在陕西蓝田的最新研究进展是运用第四纪地质学与古人类学和旧石器考古学交叉学科的综合研究方法,以黄土-古土壤序列和高分辨率磁性地层年代框架为依据,发现了公王岭遗址黄土地层的强烈侵蚀和多组地层缺失,确定了直立人头盖骨与伴生的古动物化石所埋藏的地层不是前人原确定的粉砂质黄土L15中部(年代为1.15 Ma),而是位于一个大侵蚀面之下的S22～S23古土壤混合层(年代为1.63 Ma).同时,在蓝田上陈一带发现了新的出露良好的连续黄土-古土壤剖面(L5～L28),并在早更新世S15～L28层段的17层黄土或古土壤层位中发现了原地埋藏的数量不等的旧石器,其年代为1.26～2.12 Ma.研究结果使蓝田地区成为迄今所知非洲以外最古老的人类活动地区之一,这不仅在人类起源和演化方面提出了新的科学思考,并拓展了"黄土石器工业"和"黄土地质考古带"的研究方向,提出了中国黄土高原高分辨率黄土-古土壤序列与多时期古人类活动序列关联研究的新设想.更多还原

【Abstract】 Many hominin sites have been found since 1920 in the Chinese Loess Plateau and its adjacent areas, such as Nihewan, Shuidonggou,Dingcun, Dali, Kehe, Xihoudu, east Qinling Mts. and Lantian. Recently two very important investigations of hominin occupation in the Chinese Loess Plateau have caused a huge impact in the world.The Homo erectus cranium from Gongwangling, Lantian County, Shaanxi Province of China is the oldest fossil hominin specimen in North China. It was found in 1964 in a layer below the Jaramillo subchron and was initially attributed to loess L15 in the Chinese loesspaleosol sequence, with an estimated age of ca. 1.15 Ma(millions of years ago). Here, we demonstrate that there is a stratigraphical hiatus in the Gongwangling section immediately below loess L15, and the cranium in fact lies in paleosol(S) S22 or S23, the age of which is ca.1.54～1.65 Ma. High-resolution paleomagnetic investigations at two sections at Gongwangling and one at Jiacun, 10 km to the north,indicate that the fossil layer at Gongwangling and a similar fossil horizon at Jiacun were deposited immediately before a short normal magnetozone above the Olduvai subchron, which is attributed to the Gilsa excursion and dated elsewhere to ca. 1.62 Ma. Our investigations thus demonstrate that the Gongwangling cranium is slightly older than ca. 1.62 Ma, probably ca. 1.63 Ma, and significantly older than previously supposed. This re-dating now makes Gongwangling the second oldest site outside Africa(after Dmanisi in Georgia)with cranial remains, and causes substantial re-adjustment in the early fossil hominin record in Eurasia.At the same time, the earliest hominin evidence outside Africa came from our newly found 2.12-million-year old stone tools, which were found at Shangchen, a paleolithic locality, in Lantian County in the southern margin of the Chinese Loess Plateau. The loesspaleosol sequence and magnetostratigraphy were established by using different methods, including marker layers, sedimentology,mineralogy, geochemistry, paleomagnetism and rock magnetism. The stone artefacts(including cores, flakes, scrapers, points, borers,hammerstones and picks) from the Shangchen locality were found in a successive loess-paleosol section, and 17 stone artefact horizons of early Pleistocene strata(1.26–2.12 Ma) were used to establish the chronological framework of the loess-paleosol-paleolithic culture sequence during the early Pleistocene. The artefact-bearing layers were dated by linking the geomagnetic polarity variations changes in the earth’s magnetic field. The oldest artefacts(2.12 Ma) found within L28 layer between the Olduvai subchron and the Réunion excursion are ca. 270 thousand years older than the 1.85-million-year old skeletal remains and stone tools from Dmanisi, Georgia, which were previously the earliest evidence of hominin outside Africa. Because no skeletal remains were found with the stone tools from Shangchen, we do not know who made them, but it is likely to be an early form of our own genus Homo.Moreover, the length of our artefact sequence with17 stone cultural horizons(probably with a high average occupation of ～ 50 ka)found in the same locality – is very rare world-wide, and indicates a repeated – but not necessarily continuous – hominin occupation of the Chinese Loess Plateau for almost a million years between 1.26 and 2.12 Ma. Most occupations occurred in the paleosol layers(11 layers of total 17 layers) which indicate a kind of warm-wet climate.This breakthrough expands the "Loess lithic industry" and the "Loessic Geoarchaeological Belt" direction of research on the internationally-leading Chinese loess-paleosol sequence, and prompts reconsideration on the pattern of early human’s origin, migration and dispersal.更多还原