CORRELATION BETWEEN UPPER PLEISTOCENE CAVE DEPOSITS AND SUPERFICIAL DEPOSITS IN THE LOWER REACHES OF THE DASHI RIVER IN FANGSHAN AREA,BEIJING MUNICIPALITY

The Upper Pleistocene strata at Sanfucun and Donglingzi are divided in descending order into three parts: The upper part——beds 1—5 of the Sanfucun section（beds 2—3 of the DongHngzi section）——consist of gingeryellow loess, 2.95～12.25m thick, yielding small amounts of mammal and mollusk fossils. The loess has been measured to have a thermoluminescent ago of 19 ka. Its horizon is equivalent to the Malan Formation of North China and its age is late Late Pleistocene. The middle part——beds 6—10 of the Sanfucun section （beds 4—6 of the Donglingzi section）——is composed of three beds of paleosol with two beds of loess, 7.72～9 m in thickness. The former has a thermoluminescent age of 87—104ka; the latter yields such animal fossils as Cervns, Nycereutes, Cricetulus, Micretus and Lepus. The horizon of this part is equivalent to the middle and upper parts of the Dingcun Formation of North China and its age is middle Late Pleistocene. The lower part——beds 11—12 of the Sanfucun section （beds 7—8 of the Donglingzi section）——is made up of sandy clay and paleosol, 5.81～7m in thickness. Its base rests unconformably on the Middle Pleistocene Zhoukoudian Formation and the Shizhongru of Donglingzi （with a uranium series age of over 100—350 Ka）. Its horizon is equivalent to the lower of the Dingcun Formation and its age is early Late Pleistocene.