北大西洋北部中全新世以来古海洋环境记录

利用主成分分析法对冰岛北部陆架 MD99-2275 孔中全新世以来沉积物硅藻数据进行研究发现,5 000 - 3 000 a B.P.,冰岛北部陆架表层古海水温度逐渐上升,来自印明格暖流的北大西洋暖水对该区域的影响有所增强.自 3 000 a B.P.以来,表层海水温度开始稳步下降,北大西洋暖水水团的影响逐步减弱,而来自东格陵兰寒流和东冰岛海流的极地冷水水团的影响显著加强.在晚全新世气候逐渐变冷的过程中,发生了几次短期而显著的气候变冷事件,分别出现在 3 000 - 2 600 a B.P.,1 300 - 1 000 a B.P.及 600- 200 a B.P..该中晚全新世古海洋环境记录与格陵兰冰芯(GSIP2)氧同位素气候记录存在良好的对应关系,也与冰岛北部陆架其他海水温度记录有较好的一致性.而冰岛北部陆架区域海底地形的复杂性和海流分布的差异性,以及所采用研究方法的不同则导致该区域各古海水温度记录之间也存在一定的差异性.     

The role of geoarchaeology in the interpretation of fragmented buildings and occupation surfaces: The case of coastal settlements in northeast Scotland

Around the world, poorly preserved buildings and occupation deposits often represent the primary evidence for archaeological structures and settlements. Integrated geoarchaeological methods, such as soil chemistry and micromorphology, can be used to maximise the information obtained from such deposits regarding site preservation and the use of space. However, archaeologists are often reluctant to apply these methods if they suspect that preservation is poor or stratigraphy is not visible in the field. To assess the role that geoarchaeology can play in the interpretation of fragmented and poorly preserved structures, this paper presents the results of two case studies in which multiple geoarchaeological methods (microrefuse analysis, pH, electrical conductivity, magnetic susceptibility, loss-on-ignition, portable XRF and micromorphology) were applied to poorly preserved occupation deposits and fragmented buildings in early medieval coastal settlements in northeast Scotland. Micromorphology proved to be fundamental for recognising and understanding the composition of occupation deposits that had formerly been floor surfaces. It also aided interpretations for the use of space and maintenance practices and improved an understanding of the post-depositional processes that had affected stratigraphic visibility at the macroscale. When subjected to principal component analysis, the geochemical, magnetic and microrefuse data were able to provide new details about activity areas, and successfully identified and filtered out the effects of post-medieval contamination. Most significantly, the integrated approach demonstrates that fragmented buildings and poorly preserved occupation surfaces can retain surviving characteristics of the use of space, even if the floor surfaces were not preserved well enough to be clearly defined in the field or in thin section.     

古代淀粉鉴别的新方法—耐热性α淀粉酶降解法

目前古代淀粉粒鉴别的两种方法,即显微镜观察法和碘着色测试法,均不能确保鉴别的准确性。针对耐热性α-淀粉酶只对淀粉产生降解的特点,设计出古代淀粉粒鉴别的"耐热性α-淀粉酶降解法",并运用到考古样品中淀粉粒的分析和鉴定之中。本文详细介绍了耐热性α-淀粉酶降解法的原理和流程,并通过古代淀粉粒的鉴别实验,确定了该方法在确切鉴别考古样品中淀粉粒的实用性和有效性; 同时现代大麦和莲藕淀粉粒的降解实验结果表明不同植物来源以及同种植物内部不同粒径的淀粉粒其降解速率存在明显差异,而古代淀粉粒在耐热性α-淀粉酶作用下出现的降解速率差异的现象,或可揭示古代淀粉粒的植物来源,甚至长期埋藏对其产生的影响。