Microfossils from Neoproterozoic Supersequence 1 of the Officer Basin,Western Australia

The discovery of a rich assemblage of microfossils from the Neoproterozoic western Officer Basin (Centralian Superbasin) provides a more complete understanding of the biostratigraphy of this Basin. The microfossils are found in Supersequence 1 (～800 Ma) in Western Australia. The assemblages are comprised of acritarchs and cyanobacteria isolated by acid maceration from siliciclastics of the Browne (Madley), Hussar, Kanpa and Steptoe Formations. The distinctive acritarchs Cerebrosphaera buickii, Satka colonialica, Stictosphaeridium sinapticuliferum and Pterospermopsimorpha insolita are of particular interest in the Neoproterozoic. These taxa are found in similar depositional environments in Spitsbergen, Arizona, Canada and Siberia. This evidence, together with lithostratographic correlations, isotope chemostratigraphy, and sequence analysis contributes to the continuing development of Neoproterozoic stratigraphy.     

Late Carboniferous to Early Permian brachiopod faunas from the Bachu and Kalpin areas,Tarim Basin,NW China

Terrestrial reptile remains are very rare in the Lower Cretaceous of South Australia, but include the holotype of the small theropod Kakuru. Here, we review this taxon and other archosaur specimens collected from the Bulldog Shale (Aptian) of Andamooka and Coober Pedy. Kakuru possesses no unique characters or character state combinations and is regarded as a nomen dubium, representing an indeterminate tetanuran theropod. Two other specimens (a left metatarsal and astragalus) can be referred to Dinosauria, but the identity of several other specimens (phalanges and a centrum) can only be resolved to the level of an indeterminate archosaur.     

复合生态系统下城市高质量发展时空演化及驱动因素研究——以黄河流域7大城市群为例

基于复合生态系统理论，构建高质量发展评价体系，考察了2010—2018年黄河流域城市群高质量发展时空演化特征与驱动因素，结果表明：①城市群高质量发展呈“下游领先、中游振兴、上游落后”的空间特征，经济发展水平与社会民生低下是首要制约因素。②高质量发展水平趋于收敛，但区域差异显著，资源环境促进高质量发展趋同。③高质量发展耦合逐年攀升，协调度下降趋势明显，东西非均衡化特征突出。④高质量发展的空间差异性由多因子共同作用，其中科技创新是核心驱动因子。     

Diagenesis and elemental geochemistry under varying reservoir oil saturation in the Junggar Basin of NW China: implication for differentiating hydrocarbon‐bearing horizons

In this paper, we attempt to differentiate hydrocarbon‐bearing reservoir horizons of the Junggar Basin of NW China based on the characteristics of diagenesis and associated elemental geochemistry. Reservoirs at this site have varying levels of oil saturation that correlate with the degree of dissolution in minerals (e.g., calcite and feldspar). Four different horizons with varying diagenetic mineral assemblages were observed, including (i) kaolinite‐rich, oil‐dominated horizons, (ii) kaolinite–pyrite–hematite‐rich, oil–water‐dominated horizons, (iii) siderite–chlorite‐rich, water‐dominated horizons, and (iv) chlorite‐rich horizons with negligible hydrocarbon production. The mean MnO content of the representative diagenetic mineral (e.g., calcite) in each of the above horizons is >2.5, 2.0–2.5, 1.5–2.0, and <1.0 wt%, respectively. We propose that the above methodology can be used for the identification of reservoir hydrocarbon‐bearing horizons. We argue that the indicators presented here can be applied in oil exploration across the Junggar Basin.     

Chiefdoms and states in the Yuncheng Basin and the Chifeng region: A comparative analysis of settlement systems in North China

Regional settlement datasets for the Yuncheng Basin and the Chifeng region are re-analyzed for comparison so as to reconstruct differing patterns of community development at local and supra-local scales. A methodological implication of this reanalysis is that comparing settlement areas and surface artifact densities between projects requires special attention to how the data were recorded so as to put them on the same measurement scale. The analytical approaches originally taken to reconstructing community organization in the two regions, while differing in several respects, are shown to produce highly compatible results, permitting a comparison of the two trajectories with a sound empirical foundation. Neolithic settlement began much earlier in Chifeng, but rates of demographic and community growth were extremely slow. In Yuncheng, early village growth was much more dramatic. Multiple chiefly districts of modest size emerged in both regions, but those of Yuncheng, despite their shorter developmental trajectory, had substantially larger populations. Their central settlements, in particular, grew to be much larger than those in Chifeng and the special activities carried out at these centers differed between the two regions. A poorly understood, but not contemporaneous, demographic disruption punctuated both sequences. It was followed by the emergence of political integration on a much larger scale in the Yuncheng Basin, focused on a single settlement an order of magnitude larger than its predecessors. In Chifeng, regional population soared far beyond previous levels, but political integration remained persistently small in scale.     

The Fremont Complex: A Behavioral Perspective

The Fremont complex is composed of farmers and foragers who occupied the Colorado Plateau and Great Basin region of western North America from about 2100 to 500 years ago. These people included both immigrants and indigenes who shared some material culture and symbolic attributes, but also varied in ways not captured by definitions of the Fremont as a shared cultural tradition. The complex reflects a mosaic of behaviors including full-time farmers, full-time foragers, part-time farmer/foragers who seasonally switched modes of production, farmers who switched to full-time foraging, and foragers who switched to full-time farming. Farming defines the Fremont, but only in the sense that it altered the matrix in which both farmers and foragers lived, a matrix which provided a variety of behavioral options to people pursuing an array of adaptive strategies. The mix of symbiotic and competitive relationships among farmers and between farmers and foragers presents challenges to detection in the archaeological record. Greater clarity results from use of a behavioral model which recognizes differing contexts of selection favoring one adaptive strategy over another. The Fremont is a case where the transition from foraging to farming is followed by a millennium of adaptive diversity and terminates with the abandonment of farming. As such, it serves as a potential comparison to other cases in the world during the early phases of the food producing transition.     

史前太湖流域社会复杂化进程初步研究

通过对太湖流域不同文化时期社会经济、社会关系以及宗教信仰三个方面考古资料的分析,将太湖流域社会发展分为均质、平等社会,初步分化社会和复杂分层社会三个阶段。