Age and division of Neogene "Red Bed"of Laogaochuan,Fugu County, Shaanxi
Zhang Yunxiang; Xue Xiangxu; Yue Leping(Department of Geology, Institute of Cenozoic Geology and Environment, Northwest University, Xi'an, 710069 )
A great number of specimens of Hipparion fauna were found in 1986, which form the basis of this paper, at Wangdaifuliang Village of Logaochuan, Fugu County,Shaanxi Province. There are about a thousand or more pieces of fossils, include skulls, tooth,horns antlers and completed limbs etc. were collected. It is the most important discovery and collection in the past decades in China. Preliminary study of the fossils and fossiliferous strata and correlation of lithostratigraphy, biostratigraphy and magnetostratigraphy showing that the red clay bed in north Shaanxi Province consists of two parts, lower one (Late Miocene)and upper one (Early Pliocene). The upper is brownish red, brick red sand mudstone and there are a lot of scattered calcium nodules, part of which formed net-nodule.The results of palaeomagnetic measurement show that it is of reversal polarity,corresponding to Early to Middle Ruscinian and dated at 5. 3～4. 36 Ma B. P. The lower one is light reddish brown, yellowish red sand clay, fine-sand clay. Fossils in this part from three layers, they are different in element, character and palaeoecology. These fossils are extensively distributed in North China, namely Gansu, Henan, Shanxi, Shaanxi, etc. Most of them are common or key fossils of the Bandenian(Late Miocene),so their age are Banodenian undoutedly. Palaeomagnetic determinations indicate that this part records the palaeomagnetic table 5r, 6r and upper part of 7r geomagnetic epoch, arouse 7. 4 Ma B. P. ～5. 3Ma B. P.,corresponding to the middle and late Turolian.
【CateGory Index】： P534