Triassic palynostratigraphy and palynofloral provinces: evidence from southern Xizang (Tibet), China

Peng, J., Li, J., Slater, S.M., Li, W., Zhu, H. & Vajda, V. October 2017. Triassic palynostratigraphy and palynofloral provinces: evidence from southern Xizang (Tibet), China. Alcheringa 42, 67–86. ISSN 0311-5518.

Palynological analysis was carried out on Middle to Upper Triassic strata from Tulong, Nyalam County, southern Xizang (Tibet), China. Well-preserved miospore (pollen and spore) assemblages and sparse acritarch occurrences were identified. We recognized four formal and one informal biozones based on stratigraphically important taxa and compositional changes through the succession, in ascending order: the Triplexisporites Interval Zone (Anisian), the Staurosaccites quadrifidus Taxon-range Zone (upper Anisian to lower Norian), the Striatella Interval Zone (lower Norian), the Craterisporites rotundus Taxon-range Zone (middle to upper Norian) and the informal ‘Dictyophyllidites harrisii zone’ (Rhaetian). The zonation was supported by marine fossils (e.g., ammonoids and conodonts), and compositional similarity between the zones was examined using non-metric multidimensional scaling (NMDS). Correlation with other representative palynological sequences across Gondwana was also conducted. The presence of miospore taxa not previously recovered from the Late Triassic North and South China palynofloral provinces (e.g., Ashmoripollis reducta, Craterisporites rotundus, Enzonalasporites vigens, Minutosaccus crenulatus, Samaropollenites speciosus and Staurosaccites quadrifidus) calls for a new province in southwestern China, i.e., the Southern Xizang Province. It is proposed here that the modern expression of the northern boundary runs along the Yarlung Zangbo Suture, the remnant of the Tethys that separated the Indian Plate (southern Xizang) and the Lhasa Block during the Late Triassic. This new palynofloral province comprises typical elements of the Onslow Microflora, indicating the need for an extension of this microflora in southern Xizang, China.

Jungang Peng [jgpeng@nigpas.ac.cn], Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China, University of Chinese Academy of Sciences, Beijing 100049, China, Department of Palaeobiology, Swedish Museum of Natural History, Stockholm 104 05, Sweden; Jianguo Li* [jgli@nigpas.ac.cn], Key Laboratory of Economic Stratigraphy and Palaeogeography, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China; Wenben Li [wenbenli@126.com], Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China; Sam M. Slater [sam.slater@nrm.se], Vivi Vajda [vivi.vajda@nrm.se], Department of Palaeobiology, Swedish Museum of Natural History, Stockholm 104 05, Sweden; Huaicheng Zhu [hczhu@nigpas.ac.cn], State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China.     

Discussion on the variation characteristics of water content of Quaternary soil cover on the top of Yungang Grottoes and the problem of water seepage in caves北大核心

为研究云冈石窟顶部土壤覆盖层的含水率变化情况,建设了土壤环境监测网收集云冈石窟土壤含水率实时监测数据,并分析其时空变化特征及影响因素。结果表明,平坦地形条件下云冈石窟顶部第四纪土壤覆盖层含水率时空变化特征明显:年变化具有周期性,垂向上随深度逐层降低(冬季除外)。春、夏季土壤含水率抬升、储水,秋、冬季下降、失水;在春、夏日土壤含水率呈白天上升、夜晚下降趋势,秋、冬日则呈白天下降、夜晚也下降趋势。土壤含水率时刻处于不停的运动变化之中,受温度、大气降水、微地形等众多因素影响,山体边坡浅层土壤可能为侧向饱和流的入渗通道。降雨对土壤含水率的影响深度与实际入渗深度不一致。云冈窟内顶板及岩壁上部、中部含水率主要受降雨渗透窟顶土壤层、沿岩体裂隙通道进入洞窟的渗漏水控制,而岩壁底部含水率更多受窟前不饱带和与地下毛细水的影响。多年的防水实践也证明云冈洞窟渗漏水主要来自于石窟顶部及附近区域。防渗排水始终是云冈洞窟渗漏水治理的主导思路,建议应根据窟顶土壤厚度、地形地貌和遗址分布等分区治理,充分发挥土壤的防渗作用,减少对土壤覆盖层的过度干预。防渗层材料在具有防渗作用的前提下,应具备一定的透气性,满足“洞窟—覆盖层—大气环境”之间的水汽循环。     

Cereal pollen grains in pre-elm decline deposits: Implications for the earliest agriculture in Britain and Ireland

Evidence of cereal type pollen grains in the pre-elm decline sections of pollen profiles is demonstrated from five sites in Ireland and three in Britain. Technical and archaeological considerations are also discussed. It is concluded that cereal cultivation in the British Isles occurred before the traditional beginnings of arable activity as denoted by the elm decline, and that the palynological data should be seen to underline caution in referring pre-elm decline pollen changes to Mesolithic disturbance.     

A review of lessivage and neolithic cultivation in southern England

A critical re-examination is undertaken of a model for soil development which has been put forward to explain the occurrence of buried sols lessivés (Argillic brown earths) under several neolithic earthworks in southern England. The model attributes the formation of sols lessivés to neolithic agricultural activity, and is based on the assumption that lessivage will not occur under woodland, but will be facilitated by clearance and cultivation. A review of the pedological literature shows both these assumptions to be unsubstantiated, and a survey of the sites used in the development of the model reveals that at only one is there any independent evidence for neolithic agriculture. An alternative hypothesis for sol lessivé development is put forward which associates it with the post-glacial forest. The original model was taken as an environmental cause of the change in the neolithic economic base. In view of the arguments presented here this explanation is no longer tenable.     

The Environmental History of Mass Graves

ABSTRACT

The author presents an ecological-necrological perspective on the ontology of the human dead body and remains in the context of Holocaust studies. The article examines the environmental history of mass graves and reflects on the ontological status and condition of human remains. The author proposes an approach that combines humanities and soil sciences while thinking about post-genocidal spaces and sites of mass killings in order to discuss the issue of protecting human remains from politicization and commercialization and to prefigure appropriate long-term approaches to the preservation of sites containing human remains. The article suggests focusing on humus while examining the process of dehumanization through decomposition (organic decay) and unbecoming human by “becoming-soil.” To enrich and problematize the humanities’ conception of humus, the article draws on conceptions of humus proposed by soil scientists. What is argued here is that the ecological perspective becomes a necessary and essential element in managing post-genocidal (and post-Holocaust) sites, particularly when it comes to planning their conservation and preservation.     

非完整性墓葬异地搬迁保护规程化研究

价值高、完整度好的墓葬越来越多选择整体搬迁保护。但在考古工作中,有结构缺损的非完整性但价值较高的墓葬不在少数。西安出土一座关中地区少见的、形制完整的宋金时期砖雕墓,尽管其结构局部缺损但研究价值高,是研究该时期墓葬形制、丧葬风俗的重要补充。为完整保留墓葬形制,兼顾再研究与展示,欲进行搬迁保护。保护前通过建立物理力学模型模拟墓室质心的偏移校正,并分析计算搬迁过程中砖壁的倾覆风险,确定了采取保留外部土圹固型、内部加固支撑的整体吊装搬迁方案;再根据理论计算出留土高度、通过模拟实验改进彩绘层隔离保护工艺,成功实现该墓葬的整体搬迁保护。本工作在文物搬迁保护中引入理论模型对缺损结构的量化评估,探究搬迁保护规程化方法,可为同类非完整性但价值较高的墓葬搬迁保护提供方法借鉴。