泥河湾盆地河湖相沉积典型剖面的年代地层学研究

泥河湾盆地的泥河湾层是我国北方早更新世河湖相沉积的典型代表，研究已近一百年，但至今仍未建立公认的标准剖面。标准剖面是地层研究最重要的成果，因此也是今后对泥河湾层集中开展研究的重要目标。.本项目拟选择小渡口-钱家沙洼一带，地层出露完好、沉积连续的剖面，通过对泥河湾盆地河湖相沉积物详细的岩石磁学及环境磁学研究，进行高分辨率的磁性地层学定年，结合岩石地层学、生物地层学、沉积学及沉积古地理等多学科的综合年代学研究，依据详细的各磁学参数进行精细的年代地层划分，建立详细的年代地层框架，确定一个典型的具有上新统至更新统界线的连续河湖相沉积剖面。为泥河湾盆地开展古气候、古生态及环境变化研究提供坚实的年代支持，同时为在泥河湾盆地建立第四系下界线层型剖面奠定基础。

The Nihewan sediments is a typical representative of the early Pleistocene lacustrine deposits in Northern China. It has been studied for nearly 100 years, but no recognized stratigraphic profile has been established. Stratotype profile is the most important achievement of stratigraphic research, and therefore is also an important target of concentrated research on Nihewan formation in the future..The Nihewan Basin is a down-faulted basin, lies approximately 150 km west of Beijing, and is located in the transition zone between the North China Plain and the Inner Mongolian Plateau. Nihewan Basin has attracted the attention of geologists, paleontologists and paleoanthropologists because of its well developed Late Pliocene to Holocene lacustrine, fluvial, and wind-blown deposits that are rich in mammalian faunas and Paleolithic sites. Recently, a plenty of investigations concerning magnetostratigraphic dating of the fluvio-lacustrine sequence in the Nihewan Basin, northern China, has been conducted, which has improved significantly to our understanding of the chronological framework of the complex stratigraphy and depositional systems in the Nihewan Basin, and further permitted the precise timing of a series of terrestrial Nihewan Formation, important Paleolithic sites and Nihewan faunas. The previously published magnetostratigraphic data documents a magnetochronological sequence of the mammalian faunas in the Nihewan Basin, with a time range of ca. 2.6-0.8 Ma and a robust magnetochronological sequence of early human colonization during the early Pleistocene in the Nihewan Basin, constrained between the termination of the Olduvai subchron and the Matuyama-Brunhes geomagnetic reversal, that is between 1.77 Ma and 0.78 Ma..In this program we intend to work closely around the previously research progress and focus on timing framework of the Late Pliocene to Pleistoence of Nihewan formation using a combination of lithostratigraphy, sedimentology, magnetostratigraphy and environmental geochemical analyses, to get the age framework of Nihewan stratigraphy. We will select representative and well exposure cross-sections around Xiaodukou and Qianjiashawa to obtain stringent age control on the Nihewan fluvio-lacustrine sequence and make the chronostratigraphic classification, in order to get a typical and continuous section. It provides a solid age support for the study of paleoclimate, paleoecology and environmental changes in the Nihewan Basin, and lays a foundation for the establishment of stratotype profiles of the lower Quaternary in the Nihewan Basin.