用趋势面方法讨论汉江中下游地区新石器时期大溪文化(6.3～5.0 ka B.P.)、屈家岭文化(5.0～4.6 kaB.P.)和石家河文化(4.6～4.0 ka B.P.)遗址空间过程,发现汉江中下游地区新石器文化的空间演化大致分两阶段:(1)屈家岭文化时期遗址沿汉江干流、涢水向上游扩散;(2)石家河时期文化遗址则以收缩为特征,主要集聚在丹江-枣阳-随州一线。结合本区中全新世气候和地貌变迁过程,认为汉江中下游遗址分布格局和遗址高程变化主要受古洪水和湖面扩张胁迫影响,遗址扩散与集聚过程特征和农业生产、文化融合等社会因素密切相关。
The carbon and oxygen isotopic compositions of the tooth enamel of mammals,including deer,wild pigs,buffaloes and domesticated pigs from the Shunshanji site,Sihong County,Jiangsu Province,China,were analyzed to reconstruct the mammals’ecoenvironments and diets,and to evaluate seasonal variations in the study area.Carbon isotopic compositions of buck samples revealed that the deer ate completely C3 plants and the environments they inhabited were relatively open and that wild pigs ate primarily C3 plants.Oxygen isotopic compositions indicated that the body sources of these two mammals were different,i.e.the deer and pigs lived in different niches within a relatively similar ecosystem.Modern domesticated pigs were isotopically more positive than the ancient wild pigs in carbon 13C values,suggesting the former ingested more C3 plants relative to the latter.Although the 18O data showed modern domesticated and ancient pigs had similar oxygen isotope compositions,their water sources were different.The carbon and oxygen isotopic patterns of premolar microsamples of ancient and modern buffaloes indicated that the plants ingested by the ancient buffalo varied with seasonal shifts,but plants ingested by the modern buffalo were relatively constant.The eco-environment of the modern buffalo was more open,warmer and drier than eco-environment of the ancient buffalo,which may be the result of the deforestation and other human activities.Ancient and modern seasonal changes were clearly recorded in the isotopic patterns and the seasonal variation amplitudes of the ancient and modern eco-environments were similar.
Palaeochannels are deposits of unconsolidated sediments or semi-consolidated sedimentary rocks depos- ited in ancient, currently inactive river and stream channel systems. It is distinct from the overbank deposits of currently active river channels, including ephemeral water courses which do not regularly flow. We have introduced a spectral characteristics-based palaeochannel information extraction model from SPOT-5 imagery with special time phase, which has been built by virtue of an analysis of remote sensing mechanism and spectral characteristics of the palaeochannel, combined with its distinction from the spatial distribution and spectral features of currently active river channels, also with the establishment of remote sensing judging features of the palaeochannel in remote sensing image. This model follows the process of supervised classification → farmland masking and primary component analysis→ underground palaeochan- nel information extraction → information combination→ palaeochannel system image. The Zhegao River Valley in the east of Chaohu Lake was selected as a study area, and SPOT-5 imagery was used as a source of data. The result was satisfactory when this method has been successfully applied to extract the palaeochannel informa- tion, which can provide good reference for regional remote sensing archeology and neotectonic research. However, the applicability of this method needs to be tested further in other areas as the spatial characteristics and spectral response of palaeochannel might be different.
