甘青文化区新石器文化的时空变化 和可能的环境动力*

气候变化引起的环境系统的变动,可以对史前文化的时空分布产生决定性的影响。甘青文化区是我国古文明发祥地之一。这里新石器文化非常发达,遗址丰富,类型齐全,为一个自成体系的古文化中心。通过分析不同类型的新石器文化的时空分布的变化,发现自大地湾文化至马家窑文化时期,研究区文化在空间上扩张,而后逐步向南退缩。这一变化和气候的干湿状况的变化密切相关。5kaB.P.气候逐步趋向干旱,导致文化分布上的空间差异,至齐家文化时期,研究区105°E以西遗址点的空间分布大大地向南收缩,而105°E以东齐家文化的分布范围和仰韶文化基本一致。     

中坝制盐遗址的孢粉分析与古植被、古环境

考古证据表明,距今4000多年以前,重庆三峡地区的中坝遗址就开始了规模性的盐业生产。为了解盐业生产的环境背景及其影响,在中坝遗址厚达12.5m的文化堆积层进行了孢粉取样和分析。AMS14C测年结果显示,这些样品分别来自新石器时代晚期(4420~3700aB.P.)、商至西周(3550~2700aB.P.)和东周(2700~2300aB.P.)。孢粉分析表明: 中坝遗址的样品均以草本植物花粉和蕨类植物孢子占绝对优势。主要以禾本科(Poaceae)、楼梯草属(Elatostema)和蹄盖蕨属(Athyrium)为主, 而乔灌木植物花粉所占比例很低,除松属(Pinus)、桦木属(Betula)、枫杨属(Pterocarya)、栎属(Quercus)花粉外,还见到夹竹桃科(Apocynaceae)、女贞属(Ligustrum)、檵木属(Loropetalum)和枫香属(Liquidambar)等亚热带树种的花粉。中坝遗址及附近地区自新石器时代以来的植被以少林、灌丛草地为主,遗址周围分布大片杂草群落,并可能有大面积的农田,表明这个地区始终存在较强的人类活动。早在新石器时代,制盐业和种植业使得低山丘陵与河谷的森林植被遭到破坏,遗址附近的河谷形成疏林草地景观。商至西周时期,尽管气候变干,但人类活动仍很强烈,似乎气候变化对盐业生产的影响不大; 东周时期的气候较为温暖湿润,制盐业和农业活动规模扩大,森林植被破坏程度加大,草坡随之增多。     

神农架大九湖15.753kaB.P.以来的孢粉记录和环境演变*

根据对大九湖297cm厚的泥炭地层10个AMS ¹⁴ C年龄的测定以及148块孢粉样品的分析,发现每块样品的孢粉(浓度)含量都很高,植物种类繁多,分属于137(科)属,可划分为6个孢粉组合带,植被类型演替大体为:含少量常绿树种的针阔叶混交林—含常绿阔叶树种的落叶阔叶林—常绿落叶阔叶林—含常绿阔叶树种的落叶阔叶林—含少量常绿树种的针阔叶混交林。孢粉带Ⅰ(15.753~11.280kaB.P.)记录了该区域晚冰期及其向全新世过渡时期冷暖波动频繁的气候条件,其中亚带Ⅰ -1(15.753~15.549kaB.P.),Ⅰ -3(14.936~14.505kaB.P.)和Ⅰ -5(12.655~11.280kaB.P.)可能分别对应最老仙女木期、老仙女木和新仙女木冷期,而亚带Ⅰ -2(15.549~14.936kaB.P.)和Ⅰ -4(14.505~12.655kaB.P.)分别对应博令和阿勒罗德暖期。孢粉带Ⅱ(11.280~9.218kaB.P.)代表了由晚冰期冷湿气候向全新世温暖气候转换的早全新世缓慢升温的过渡时期。孢粉带Ⅲ(9.218~7.530kaB.P.)代表中全新世前期的气温波动上升期,7.7kaB.P.前后达到最高温。孢粉带Ⅳ(7.530~4.051kaB.P.)代表中全新世适宜期,水热配置条件最佳。孢粉带Ⅴ(4.051~0.911kaB.P.)体现晚全新世温干的气候。孢粉带Ⅵ(0.911~0kaB.P)反映了大九湖温凉稍湿的气候。     

Climate Change,Geopolitics, and Human Settlements in the Hexi Corridor over the Last 5,000 Years

Social responses to climate change over human history have been widely discussed in academia over the last two decades. However, the transformation of the human–environment nexus crossing prehistoric and historic periods and the processes associated with it are not yet clearly understood. In this study, based on published works on radiocarbon dating, archaeobotany, zooarchaeology, and archaeological sites, together with a synthesis of historical documents and highresolution paleoclimatic records, we trace the extent to which human settlement patterns in the Hexi Corridor in northwestern China evolved in conjunction with climate change over the last 5,000 years. A total of 129 Neolithic, 126 Bronze Age, and 1,378 historical sites in the Hexi Corridor(n=1,633) were surveyed. Our results show that, in the Late Neolithic and Bronze Age periods(～2800–100 BC), climate change contributed to the transformation of subsistence strategies and the subsequent changes in human settlement patterns in the Hexi Corridor. The warm-humid climate in ～2800–2000 BC promoted millet agriculture and helped the Majiayao, Banshan, and Machang Cultures to flourish. The cold-dry climate in ～2000–100 BC resulted in the divergence and transformation of subsistence strategies in the Xichengyi–Qijia–Siba and Shajing–Shanma Cultures and in a shift in their settlement patterns. However, in the historical period(121 BC–AD 1911), human settlement patterns were primarily determined by geopolitics related to the alternating rule of regimes and frequent wars, especially in the Sui–Tang dynasties. We also find that trans-Eurasian cultural exchange since ～2000 BC improved social resilience to climate change in the Hexi Corridor, mediating the human–environment nexus there. Our findings may provide insights into how human societies reacted to climate change in arid and semi-arid environments over the long term.     

新疆孔雀河北缘中更新世湖相沉积物的孢粉植物群初步研究

文章对新疆孔雀河北缘的西大沟剖面中更新世湖相沉积物开展ESR测年和孢粉记录研究。结果显示,该剖面湖相沉积自730kaB.P.延续到360kaB.P.。这一期间,研究区为落叶阔叶林植被,林下生长灌木和草本,低洼潮湿的地方生长蕨类孢子和藻类。植被的主要类型有栗(Castanea)、栎(Quercus)、松(Pinus)、柏(Cupressaceae)、蒿(Artemisia)、藜(Chenopodiaceae)、莎草(Cyperaceae)等,同时还含有少量的山核桃(Carya)、枫香(Liquidambar)及枫杨(Pterocarya)等亚热带孑遗植物花粉。这与前人研究发现中更新世研究区发育大湖的认识颇为一致。具体来说,组合带A(730~640kaB.P.),C(595~505kaB.P.)和E(440~385kaB.P.)阔叶树花粉含量高,而灌木和草本花粉含量低; 组合带B(640~595kaB.P.),D(505~440kaB.P.)和F(385~350kaB.P.)阔叶树花粉含量低,而灌木和草本花粉含量高,揭示中更新世研究区气候总体上呈现冷干-暖湿的气候波动特征。这一气候变化特征和模式与甘肃白水剖面多种风化指标揭示的相应时段风化强度波动可以对比,与全球深海氧同位素记录以及海平面波动也可以对比。不过,这一气候变化规律的内部驱动机制还有待进一步深入研究。     

Holocene alluviation and land-use change on Callaly Moor,Northumberland, England

Archaeological survey and palaeoenvironmental investigations in Coe Burn, Callaly Moor, Northumberland, have examined the chronology and nature of prehistoric and historic land-use change in a small upland river catchment. These studies have revealed an intensively used landscape with evidence of late Neolithic to Bronze Age, medieval and post-medieval land use and settlement. Two episodes of valley floor alluviation are identified and dated to the middle-late Bronze Age and post-medieval periods. Magnetic mineral and geochemical analyses of fine sediments from the older alluvial fill show it to contain a high proportion of topsoil, which is believed to have been produced by soil erosion resulting from Bronze Age tree clearance and cultivation. Deposition of the younger alluvial fill (post AD 1500) was associated with the inwash of relatively unweathered bedrock generated by coal mining in the catchment. It is demonstrated that by integrating archaeological field survey with off-site palaeoenvironmental investigations a much fuller picture of human activity and land-use change has emerged than otherwise would have been the case. Studies of this type may be particularly useful in other upland river catchments where archaeological survival is limited or poor.     

榆林地区全新世聚落时空变化与人地关系

在对榆林地区仰韶时期至西周聚落遗址时空分布及考古资料分析的基础上,探讨了区内聚落分布同环境变化的关系。研究表明,本区全新世气候具有较大幅度的变化历史,与其相应的人类活动同样具有强烈的兴衰变化特点,表明气候变化对人类活动产生了重要影响。但在5～4kaB.P.前后,在气温和降水有所降低的背景下,人类文化却得到进一步发展,进入鼎盛时期,说明除了当时的环境仍较为适宜外,社会发展自身规律对人类文化发展也有重要影响。研究表明,本区全新世人类文化发展可以划分为3个阶段: 自仰韶文化半坡类型时期开始,榆林地区的气候处于全新世鼎盛期,吸引南来移民在此定居,6.5～4.5kaB.P.的约2000年间形成的遗址有127处;  龙山前期气候较为适宜,4kaB.P.后气候转向干凉,但由于环境条件仍然较为适宜和人类社会自身发展规律的影响,在 4.5～3.7kaB.P.仅800年的时间形成的遗址多达740处,分布范围有所扩大;  商代和西周时期,由于气候的进一步干凉化,对人类文化发展产生了严重的负面影响,使得该时期遗址数量大幅减少至77处,表明当时人口的显著减少和社会繁荣程度的明显退步,且畜牧业在经济中的比重有所增加。     

长江三峡中坝遗址地层中Rb和Sr的分布特征及其古气候演变

长江三峡中坝遗址是我国目前仅有的、世界上也罕见的“通史式”遗址。它不仅蕴藏大量的文化内涵,而且包含极其丰富的自然环境演变信息,是研究三峡地区全新世环境演变的理想剖面。文章对遗址地层中的铷(Rb)、锶(Sr)值进行了测试和分析,结果显示:剖面地层中的Rb含量偏低,而Sr含量偏高,Rb/Sr比值变化较大。Rb/Sr比值已成为区域环境演变研究中较理想的替代指标,根据Rb/Sr比值的环境指示意义发现,长江三峡地区全新世中晚期以来气候环境总体上逐渐趋于恶劣;气候冷暖湿热变化剧烈;寒冷期长于温暖期,并没有明显地向湿热方向发展趋势。与长江下游等东部其他地区相比,长江三峡地区也存在明显不同之处:隋唐暖期不明显,而中世纪暖期表现显著。     

长江三峡中坝遗址地层中Rb和Sr的分布特征及其古气候演变

长江三峡中坝遗址是我国目前仅有的、世界上也罕见的“通史式”遗址。它不仅蕴藏大量的文化内涵,而且包含极其丰富的自然环境演变信息,是研究三峡地区全新世环境演变的理想剖面。文章对遗址地层中的铷(Rb)、锶(Sr)值进行了测试和分析,结果显示:剖面地层中的Rb含量偏低,而Sr含量偏高,Rb/Sr比值变化较大。Rb/Sr比值已成为区域环境演变研究中较理想的替代指标,根据Rb/Sr比值的环境指示意义发现,长江三峡地区全新世中晚期以来气候环境总体上逐渐趋于恶劣;气候冷暖湿热变化剧烈;寒冷期长于温暖期,并没有明显地向湿热方向发展趋势。与长江下游等东部其他地区相比,长江三峡地区也存在明显不同之处:隋唐暖期不明显,而中世纪暖期表现显著。     

Holocene landscape evolution and its impact on the neolithic and bronze age sites in the Shangqiu area,Northern China

The Shangqiu area, situated on the alluvial plain of the lower Yellow River, is traditionally considered the center of the predynastic and early Shang culture. Archaeologic remains dating to predynastic and dynastic Shang periods, however, have remained elusive. The current pattern of Neolithic and Bronze Age sites is characterized by their upland settings; and it has been often assumed that the area had the same landscape from the Neolithic through recent historic time. The potential impact of geomorphic processes on these early sites has been hardly considered in developing archaeologic models of temporal and spatial distribution of these sites. This article first presents a reconstruction of the Holocene floodplain history in the archaeologically significant area. On the basis of stratigraphy and sedimentology, a Holocene landscape evolution model is constructed to explore the interrelationship between evolving landscape and archaeologic record of the Neolithic and Bronze Age. The prolonged landscape stability from very late Pleistocene or early Holocene to 2000 yr B. P. provided potential Neolithic and Bronze Age human occupation with a favorable physical environment. After 2000 yr B. P., the hydrologic regime changed and the floodplain experienced 2-3 m of gradual vertical accretion during the following millennium. In response to the dramatic change of hydro-logic regime after the early 12th century A. D., a new floodplain formed by dominantly overbank deposition, and the old floodplain surfaces are covered by as much as ten meters of the younger alluvium. As a result, a pronounced effect has been imposed on the preservation, visibility, and discovery of the Neolithic and Bronze Age sites, including those sites of predynastic and early Shang phases. Thus, much difficulty has been imparted to our understanding of the configuration of these early archaeologic sites. This study demonstrates the usefulness of landscape reconstruction in developing settlement models of Neolithic and Bronze age sites in the area.     

吉林柳河哈尼湖13.1～4.5cal.kaB.P.古气候演化的高分辨率孢粉记录

利用哈尼湖钻孔剖面深837～304cm高分辨率的123个孢粉数据和序列中的8个14C测年数据重建中国东北地区13.1～4.5cal.kaB.P.的植被与气候历史:13.1～11.9cal.kaB.P.植被变化明显,整个时段气温较低,后期有回暖趋势,在12.8～12.1cal.kaB.P.的快速变干可能是新仙女木事件在本区的体现;11.9～10.0cal.kaB.P.孢粉显示为以云杉、冷杉等针叶树为主,气候湿冷;10.0～8.2cal.kaB.P.针叶林逐步演替为落叶阔叶林,为升温阶段;8.2～4.5cal.kaB.P.落叶阔叶林进一步发展,气候温暖湿润。同时孢粉序列也反映出,东北地区在气候变暖后发生了一系列的冷暖干湿波动,大致可与我国北方和南方其他地区的气候事件对应。经频谱分析表明,本区在研究期间存在1100a,700a,500a及300a的气候变化的准周期。     

江汉平原北部汉水以东地区新石器晚期文化兴衰与环境的关系

新石器晚期江汉平原北部汉水以东地区成为长江中游的文化核心区,出现了文化高度繁荣又快速衰落的逆转,处于发展初期的区域文明走向崩溃。文章基于屈家岭剖面常量元素氧化物和TOC含量的分析结果,综合多种环境要素,探讨汉水下游地区全新世中晚期地貌、气候、水文等环境变化与文化兴衰的关系。研究认为,该地区5.4～4.6kaB.P.的气候整体暖湿,晚期暖湿程度有所降低;4.6～4.2kaB.P.气候较为稳定,温暖湿润程度有所回升; 4.2～2.7kaB.P.气候处于持续变干凉阶段; 2.7～0.5kaB.P.气候温湿程度开始回升,并略有波动,但比4.2kaB.P.前仍然偏干凉。以岗状平原为主的江汉平原北部地区优越的地理环境,整体暖湿的气候,为屈家岭文化、石家河文化的高度繁荣提供了环境基础,该时期的聚落数量和分布密度达到了长江中游新石器时期的最高峰。石家河晚期的气候变干变凉,对文化发展产生了一定影响,但不是石家河文化衰落的主要原因。该地区5～3kaB.P.的水位存在波动上升的趋势,这种变化主要受构造沉降、全新世以来海面上升和泥沙淤积的控制。江湖水位的波动上升而引起的洪患加剧,及人类活动向地势低平的江汉平原腹地扩展,这种水文过程和社会发展过程的矛盾,到石家河文化晚期尤为突出,可能是导致石家河文化走向衰落的主要原因。该地区内部或同其他地区之间的冲突可能加速了石家河文化的崩溃。     

中国古代牧业社会骨制品的初步考察:以新疆巴里坤石人子沟遗址为例

考古遗址出土骨制品的研究对于揭示古代社会的动物资源获取和利用、手工业生产、社会组织结构等问题具有重要意义。国内骨制品研究目前多集中在农业区域,这些研究为探讨新石器时代至青铜时代的动物使用及其与社会发展、早期国家形成的关系等问题作出了重要贡献。然而,针对牧业社会骨制品的考察十分缺乏。新疆哈密地区巴里坤草原分布有大量古代牧业文化遗址,石人子沟遗址（43°31'12.8"~43°34'28.9"N,93°13'44.8"~93°16'49.1"E）是其中一处青铜时代晚期至铁器时代早期的大型聚落。本文从动物考古学视角研究该遗址2006年至2011年发掘出土的426件骨制品。结果显示,石人子沟遗址骨制品的原料主要为以羊（Ovis aries/Capra hircus）、马（Equus caballus）为主的家养动物和以鹿（Cervidae）为主的野生动物,其中羊的比例最高（69.7%）,鹿（13.8%）、马（2.3%）次之,这与中原地区青铜时代农业文化遗址的骨制品多以牛为原料的情况明显不同。羊在骨制品原料中占绝对多数且大量使用羊距骨制品的现象是对石人子沟遗址以牧业为主的生业经济方式的直接反映。石人子沟遗址不同类型骨制品的制作各具特点,但整体表现出"省时省力"的特点,即对使用部位细致打磨,对非使用部位仅做简单处理。与中原地区商周时期大型制骨作坊规范化、规模化、产业化的骨器生产不同,石人子沟遗址未见专门的制骨场所,骨制品生产的操作链条也并不完整。遗址的骨制品生产可能是以家庭为单元进行的,产品的专业化、精细化程度也相对较低。该研究填补了我国古代牧业文化遗址出土骨制品动物考古学专门研究的空白,为进一步探究我国古代不同区域、不同生业经济基础下的制骨手工业面貌提供了重要资料。

     

中国北方晚第四纪气候变化的沙漠与黄土记录* ——以光释光年代为基础的直接对比

中国北方有约200×10⁴km²的面积被黄土、沙漠和荒漠戈壁沉积物覆盖,这些地区堆积物的形成变化与第四纪气候变化密切相关。关于中国北方沙漠与黄土记录晚第四纪古气候变化的研究不少,但是,由于受到方法和条件等限制,系统的(高密度的)和独立的年代学工作比较薄弱,从而使诸多已经发表的关于沙漠-黄土记录的亚轨道时间尺度气候变化的结论受到质疑。文章通过对黄土高原代表性的4个末次冰期以来的黄土剖面以及毛乌素、浑善达克和科尔沁沙地的20多个末次冰期-全新世的沙-砂质古土壤剖面的研究,获得了150多个独立的光释光年龄数据。在此基础上,结合200多个样品的粒度、有机质含量和磁化率数据,重建末次冰期以来中国北方气候变化过程,对比分析沙地与黄土古气候记录的联系。结果表明,中国北方古气候在57.5~52.5kaB.P.相对干旱,41.5~37.3kaB.P.相对湿润,26~22kaB.P.逐渐干旱,22~18kaB.P.极端干旱,15~10kaB.P.干旱,10~8kaB.P.为干旱减弱的时期,8.0~2.4kaB.P.相对湿润,而2.4kaB.P.以来气候为相对干旱。其间,在8.0~2.4kaB.P.的湿润时期有几次干旱事件,而2.4kaB.P.以来气候变化频繁。具有独立年代控制的黄土和沙漠记录表明,中国北方的气候变化对轨道时间尺度的太阳辐射变化有大约3~4ka的滞后。     

云南祥云红土坡墓地出土人骨颅面特征研究——兼谈“昆明”族属问题

红土坡墓地是滇西洱海地区青铜时代晚期的一处重要墓地。对红土坡墓地出土的3例颅骨标本进行性状观察、测量分析等综合研究,其颅面特征可以概括为长颅型、正颅型结合狭颅型,中等眶型和较阔的鼻型,中等面宽,偏低的面高,中等偏大的上面部扁平度。红土坡居民应属于亚洲蒙古人种范畴,与南亚类型在眶鼻和上面部形态上表现出更多的一致性。在与古代人群的对比中,与楚雄元谋磨盘山组最为相似,颅型方面皆为长颅型、正颅型,在眶型、鼻型、面宽、面高和面部扁平度等方面也非常接近;其次为华南地区的佛山河宕组和闽侯昙石山组。在综合分析的基础上,进一步探讨了云南地区古代居民颅面特征中"北方因素"的出现,以及红土坡居民所代表的"昆明"人的族属问题。

     

Bronze Age at Lake Bourget (NW Alps, France): Vegetation, human impact and climatic change

Pollen analyses of three sediment cores performed on the archaeological lake dwellings of Chindrieux and Tresserve (Savoie, France), on the eastern shore of Lake Bourget, enable the reconstruction of vegetation history and human impact during the Bronze Age. Results show a good correlation between lake-level fluctuations and the evolution of anthropogenic indicators. The end of the Neolithic period and the early Bronze Age are characterised by a discreet occupation of the Lake Bourget surroundings, in spite of a warmer climatic condition. The middle Bronze Age, contemporaneous with wetter and cooler conditions, is related to a decrease in pollen of cultivated plants and weed. Farming activities reappear in the late Bronze Age and human impact increases suddenly at the very end of the late Bronze Age. Three anthropogenic phases are clearly visible: a short decrease in anthropogenic indicators and a high lake-level phase occur in the middle of this period of intense farming development. A new decrease in human impact appears at the beginning of the Iron Age.     

柴达木盆地克鲁克湖全新世气候变化的正构烷烃分子记录

对位于青藏高原北部柴达木盆地内的克鲁克湖钻孔沉积物中的正构烷烃进行了详细定量分析。根据正构烷烃Paq指数和叶蜡烷烃平均链长(ACL27~33)等参数的变化特征,探讨了湖区过去12kaB.P.以来的古气候变化特征。结果表明: 该区域在9kaB.P.之前的早全新世气候干旱,9~6kaB.P.是整个全新世相对最湿的阶段,6kaB.P.之后气候又逐渐趋向于干旱,但干旱程度要弱于早全新世。这一全新世气候变化样式与受西风影响的亚洲内陆干旱区全新世以来的气候变化样式基本一致,但与同一钻孔沉积物中CaCO3含量和孢粉 A/C 值所重建的古气候变化过程存在一定差别。这种差别主要体现在6kaB.P.以后的重建结果。我们推测,6kaB.P.后,禾本科植物在湖盆周围植被中的比例显著增加可能是导致上述差别的一个重要原因。本工作表明,在古环境重建中,采用多指标相,互相验证,互相补充,会有利于获得更准确、更详细的古植被及古气候变化历史。     

Preliminary environmental historical results to reconstruct prehistoric human-environmental interactions in Eastern Hungary

Palaeoenvironmental research is playing an important role in recent archaeological investigations. We present preliminary results of geoarchaeological analyses conducted at a palaeochannel located between two prehistoric archaeological sites in eastern Hungary. The study area lies within the Körös River Basin in Békés County, a region of intensive human occupation beginning in the Neolithic, ca. 7550 BP, and represents only the second palynological analysis done in conjunction with archaeological investigations and adjacent to an archaeological site in the Körös region. Pollen from an environmental monolith was used to reconstruct the local vegetation composition and the human impact on arboreal and non-arboreal vegetation near the archaeological sites. Sediment analyses helped to reconstruct hydrological activity and human impact on the local palaeochannel. Results indicate that activity from the Neolithic onwards played an important role in local environmental change, including increasing sedimentation and deposition of organic matter in the local waterway, some forest clearance and a shift from primarily arboreal vegetation to more grasses on elevated surfaces. The trophic status of the local channel changed several times during the Holocene. In addition, indications that groundwater levels may have been fluctuating during the period of human occupation, when combined with the other changes in the area, provide a possible partial explanation for changing settlement patterns.     

First Reconstruction of the Habitat of Hunter-Gatherers in the Mamakan Archaeological Area in the Middle Holocene,Patom Highlands

The first radiocarbon-dated pollen record from the Mamakan section is presented. This record has become the basis for the reconstruction of the vegetation and climate of the Middle Holocene in the Mamakan archaeological area, where a number of well-known Siberian archaeological sites of the Late Mesolithic–Middle Bronze period are located. Reconstructions suggest that sparse spruce and larch stands dominated in the area between 6450 and 6150 cal BP. Later, from 6150 to 4700 cal BP, Scots pine began to spread in a warmer climate than before, following the general trend of its expansion in the southern part of Eastern Siberia. A cooler climate than previously with increased soil and air humidity occurred in the Mamakan region from 4700 to 3840 cal BP, causing the regional expansion of Siberian pine. The time interval from 3840 to 3600 cal BP was characterized by the significant development of pine, spruce, and larch forests. On the basis of the age model, we assume that, in the lower reaches of the Vitim River and, probably, in other mountain regions north of Lake Baikal, Scots pine spread about 600 years later than in the Cis-Baikal region and east of the lake. This transition from dark coniferous-taiga to light coniferous-taiga with a predomination of Scots pine signifies the most fundamental change in vegetation of the Baikal region in the Holocene. This is often discussed as one of the possible causes of the Middle Neolithic cultural hiatus (6660–6060 cal BP), which has been documented in the archaeological records from different parts of this vast region. Reconstruction of vegetation in the Mamakan region suggests that the territory of the Nizhnii Vitim River has been favorable for humans during most of the hiatus recorded in the Cis-Baikal area and may have been considered as a refuge for populations of hunter-gatherers in the Middle Neolithic.

     

Palynology,sedimentology and palaeoecology of the late Holocene Dead Sea

Palynological and sedimentological studies were performed at two Holocene profiles in erosion gullies (Ze’elim and Ein Feshkha) which dissect the retreating western shore of the Dead Sea. The aim of the project was to analyse possible links between climate, lithology, and vegetation development. The section in Ze’elim shows both lacustrine and fluvial sediments, whereas sedimentation at Ein Feshkha is predominantly lacustrine. The Ze’elim profile, previously used for paleo-lake reconstruction provides an opportunity to compare climate triggered lake levels as paleo-hydrological indicators and vegetation history by use of palynology. The vegetation development in Ze’elim and Ein Feshkha is influenced by both climate and human impact. The pollen record of Ze’elim begins in the Pottery Neolithic, the section of Ein Feshkha in the Late Bronze Age, both records end in the Middle Ages. The Ze’elim section is characterized by sedimentary hiati between the beginning of the Chalcolithic Period until the Middle Bronze Age and within the Late Bronze Age. Settlement periods during the Middle Bronze Age, Iron Age and Hellenistic–Roman–Byzantine Period are indicated by high values of anthropogenic indicators and/or Mediterranean trees. Collapses of agriculture, which can be related to climate effects, are evident during the Late Bronze Age, during the Iron Age and at the end of the Byzantine Period when the lake level curve indicates arid conditions. A comparison of the two pollen records, from different environments, illustrates a more prominent influence of Mediterranean vegetation and cultivated plants in the pollen diagram of Ein Feshkha. The southern Dead Sea region (at the desert fringe) is more vulnerable to regional climate change.