- 责任者：Liu Yaoliang (Hebei Key Laboratory of Environmental Change and Ecological Construction ; College of Resource and Environment ; Hebei Normal University ; Shijiazhuang 050024 ; China) ; Xu Qinghai
- 刊名：Quaternary Sciences
- 出版年：2013
- 卷期：33(3)
- 关键词：全新世 ; Holocene ; 孢粉组合 ; palynological assemblage ; 河南 ; Henan Province
- 页码：p.536-544
- 图表：illus., 1 table, 43 refs.
- 分类号：1400
- issnNo：ISSN1001-7410
- isbnNo：CN11-2708/P
Sanyangzhuang profile （35°43＇39.12＂N, 114°46＇24.22＂E; elevation 57m ） located in the north of Sanyangzhuang village in Neihuang County, Henan Province. It was close to the Sanyangzhuang archaeological site which was deeply buried by the Yellow River alluvium and maintained the original status of the Han period village. The strata in this area consist of several paleosol layers and palaeoflood sedimentary layers. The stratigraphie sequences of Sanyangzhuang profile are continuous without obvious hiatus,and ten sedimentary layers included five paleosol layers and five palaeoflood sedimentary layers were identified. The profile was dated from the beginning of the Early Holocene to Han Dynasty according to AMSX4C dating results and archaeological dates. In order to understand the environment evolution process and find the relationship between palaeoflood and pollen assemblage in this area. Samples from 850 -212cm below the surface were collected for pollen analysis.In total,89 pollen taxa were identified in 160 pollen samples that were taken from Sanyangzhuang profile with 2 -8em intervals. Based on the results of pollen analysis, the process of the change of vegetation and climate in Sanyangzhuang area can be divided into three periods： 10200 -7200cal. aB. P., the climate became warm, and the precipitation increased after the Younger Dryas Event, the paleovegetation was coniferous and broad-leaved mixed forest and grassland; During the period of 7200 -4500cal. aB. P.,the pollen concentration and broad-leaved pollen percentage increased significantly, along with the sub-tropical evergreen pollen taxa appeared, such as Platycarya and Rhus. The pollen assemblages indicated warmer climate and higher precipitation which was characters of the Megathermal in Holocene; 4500 -2000cal. aB. P., some pollen types such as Pieca and Nitraria appeared frequently, at the same time, the broadleaved pollen percentages decreased, the results showed that the climate had a trend of turning cold and aridity.Through a comparative research on the percentages of arboreal pollen of paleosol layers and palaeoflood sedimentary layers,it is clearly to discover that the arboreal pollen percentages of palaeoflood sedmentary layers were higher than paleosol layers in common. The reasons maybe mainly related to three factors： pollen source, grading function of river and human activity. The disparity of arboreal pollen percentages will be expanded especially when the pollen assemblages of paleosol layers were disturbed by some kind of human activities. The strata in this area can also be divided clearly by pollen assemblage.
The pollen assemblage indicated early agriculture and human activity may have existed in this area since early Holocene,but this requires further confirmation by other proxies. It can be found that human activity had no complete disappearance even though this area suffered several flood attacks. Beginning in the Middle and Late Holocene（ ca. 6000cal. aB. P. ）, the ancient cultivated land was founded in the profile, and the abrupt drop of arboreal pollen percentage and the significant growth of Selaginella sinensis percentage revealed the intensive human activities.