OSL ages and possible bioturbation signals at the Upper Paleolithic site of Lagoa do Bordoal,Algarve, Portugal

Three sediment samples were collected from a soil profile at the Lagoa do Bordoal site, Algarve, Portugal. Quartz extracted from soil horizons within the profile, was optically dated using the single-aliquot regenerative-dose (SAR) protocol outlined by Murray and Wintle (Radiation Measurements 5 (2000) 523). The optically stimulated luminescence (OSL) emitted by quartz within the 90–150 μm size range was measured using three aliquot sizes. The equivalent doses (D_E) that were obtained show an asymmetric distribution. As the numbers of grains in each aliquot are reduced, the distribution of doses is clearly shifted to lower D_E values including zero doses on single grain aliquots. This shift is accompanied by an increase in the asymmetry of the distribution. These patterns indicate that as the aliquot size decreases, the distributions are increasingly characterized by aliquots with lower D_E's. With respect to the present day modern surface, this shift is most evident in the sample collected from a depth of 37 cm, within an ancient B-horizon. It is least evident in the sample located only 10 cm below it, within a sand unit. An asymmetric distribution of D_E's can be a result of a large number of grains that were well bleached at burial being mixed with a small number of grains that were partially bleached at that time (Radiation Measurements 30 (1999) 207). However, the shift in D_E's that is seen in the Lagoa East samples is most likely due to the postburial downward movement of fully and partially bleached grains from the surface, with possible contributions from the downward movement of grains that received low doses while buried in overlying horizons. The simplest explanation for our results is that grains carrying zero or small D_E's have been moved downward during bioturbation events. These results suggest that downward bioturbation in ancient soil profiles can be identified based on the OSL characteristics of quartz grains. We are also able to provide a minimum age of 24.4±3.2 ka for the Upper Palaeolithic lithic assemblage at the site.     

Geochemistry and origin of lower crustal granulite facies rocks in the Serra do Caparaó region, Espirito Santo/Minas Gerais, Brazil

Rocks of the Serra do Caparaó region, on the border between the Brazilian states of Espirito Santo and Minas Gerais, comprise granulitic (charnockitic) sequences that have undergone Brasiliano-aged metamorphism (586 ± 2 Ma.). Thermobarometric results document pressures between 8.1 kb and 10.6 kb and temperatures up to 700 ± 50°C. Chemical analysis show a calc-alkaline (CAC) trend with granodioritic, tonalitic-trondhjemitic chemistry. K₂O/Rb data represent low- to mid-pressure charnockites corresponding to the undepleted granulite types. Discriminant analyses and diagrams indicate a source rock characteristic of sedimentary origin. REE patterns show slight to moderate fractionation and also slight negative as well as positive Eu anomalies. REE trends and the total amounts of REE of the acidic to basic rock series are similar to those of North American and Australian post-Archaean shales. The granulite facies rock series in the Serro do Caparaó region are interpreted as having originated from supracrustal rock series—i.e., graywackes, which represent sedimentary sequences derived from a Lower Proterozoic bimodal magmatic suite.     

Paleoenvironmental reconstruction of a Late Quaternary lagoon system in southern Brazil (Jaguaruna region,Santa Catarina state) based on multi‐proxy analysis

This paper provides a paleoenvironmental reconstruction of a Late Quaternary lagoon system in the Jaguaruna region of Santa Catarina state, southern Brazil. Integrated results of bulk sedimentary organic matter characterization (δ¹³C, δ¹⁵N and C/N), microfossil (pollen and diatom) and grain‐size analysis from three shallow cores (～2.5 m depth) allowed us to propose an evolving paleogeographic scenario in this coastal region for the last ca. 5500 cal a BP. The lagoonal system in this area was more extensive during the mid‐Holocene than today, with a gradual and continuous lagoon–sea disconnection until the present. We add to the debate regarding relative sea‐level (RSL) variations for the Brazilian coast during the Holocene and discuss the importance of sedimentary dynamics for interpreting changes in coastal ecosystems. The multi‐proxy analysis suggests that changes in coastal ecosystems could be directly related to local sedimentary processes, which are not necessarily linked to RSL fluctuations and/or to climatic variations. Copyright © 2011 John Wiley & Sons, Ltd.     

贵州盘县新民地区关岭组中三叠世盘县动物群产出层段碳酸盐岩微相分析和古环境恢复

通过野外观察和显微镜下碳酸盐岩薄片微相分析,以颗粒类型、颗粒基质含量对比、沉积组构、化石生物组合、化石埋藏学特征作为主要微相类型的划分依据,贵州中三叠世盘县动物群产出地层78-91层及上覆地层92层和下伏地层77层共识别出10种微相类型,在垂向上归纳为三种向上变浅的沉积相序列：开阔台地、局限台地、潮道环境。按照水深及水...     

京山屈家岭地区全新世中晚期环境变化及其对人类活动的影响

通过对江汉平原北部的野外考察,结合屈家岭剖面粒度、Rb/Sr比值、磁化率和已有孢粉结果的综合分析,揭示了该地区全新世中晚期沉积环境和气候变化特征。结果表明,该剖面沉积物中粉砂(62.5～4μm)、粘粒(<4μm)约占其总量的95%以上,属于略含细砂的粘土质粉砂,概率累积曲线以三段式为主。结合地貌和岩性分析,确认该剖面以河流相沉积为主。沉积物粒度组成以粒径<30μm组分为主,同黄土的众数组分类似。也有部分样品的概率累积曲线呈现出北方黄土和下蜀黄土多见的两段式,但概率累计曲线段的斜率和中、细粒组分的相对含量都同黄土有差异。粒度组成方面同黄土沉积的某些相似特征说明,青木垱河流域广泛分布的黄土沉积可能影响了该剖面的沉积特征。沉积样品的磁化率、Rb/Sr比值和已有的孢粉分析结果反映的气候变化趋势基本上是同步的。5.2kaBP以来屈家岭遗址附近区域气候变化可以分成3个阶段:5.2～4.2kaBP期间,是较为温暖湿润的时期,水热条件好于现在,后期暖湿程度有波动性降低的趋势;4.2kaBP开始气候暖湿程度明显下降,气候转向干凉;2.0kaBP以来,本地区气候暖湿程度有所回升。该地区包括气候在内的环境变化,一定程度上影响了新石器晚期文化的演化历史。     

非花粉类遗存(Non-Pollen Palynomorphs)分析在考古学中的应用——以浙江井头山遗址为例

非花粉类遗存(Non-Pollen Palynomorphs)包括在花粉分析过程中可以同时观察到的真菌、藻类、无脊椎生物等来源的微体化石,可以反映环境和人类活动。相比于国际上四十余年的研究历史,我国的零星研究案例主要集中在青藏高原和长江下游地区,在空间和时间上都存在大量空白,特别是缺乏对考古遗址堆积物样品的研究。本研究总结了非花粉类遗存在考古学中的指示意义,并以浙江井头山遗址为例进行分析。对井头山遗址贝丘堆积物样品的分析结果表明,粪生型、纤维素分解型和植物寄生型真菌孢子在主要文化堆积中大量出现,显示粪便、古人利用的纤维素材料以及其他植物遗存与贝类在堆积中共存,均来自古人生活的废弃物。与长江下游其他地点自然沉积物及考古遗址堆积物的分析结果比较,井头山遗址贝丘堆积中真菌孢子的组合存在差异,可能与不同的人类活动有关。

     

Facies analysis of tertiary alluvial fan deposits in the Jundiaí region, São Paulo, southeastern Brazil

This article presents an analysis of facies of sedimentary sequences that occur as discontinuous bodies in the Jundiaí region, west of the main Tertiary continental basins of the southeastern Brazil continental rift. Nine identified sedimentary facies, grouped into four associations, suggest the existence of an ancient alluvial fan system whose source area was the Japi mountain range (Serra do Japi). The deposits are considered Tertiary in age and chronocorrelated with those identified in the Atibaia region and at other sites up to 100 km east and northeast of Jundiaí. The depositional model adopted to explain the filling of the basin proposes that the alluvial fans, which directly derive from the source area, terminated in a braided channel longitudinal to the basin axis that flowed to northwest, in a similar configuration to that of the present day. This basin may have extended to the Atibaia region or formed a set of small basins laterally contiguous to the faults associated with the rift. Such occurrences show that the formation of rift basins was broader than the area presently occupied by the main deposits.     

Late Quaternary environmental and human events at En Gedi, reflected by the geology and archaeology of the Moringa Cave (Dead Sea area, Israel)

The Moringa Cave within Pleistocene sediments in the En Gedi area of the Dead Sea Fault Escarpment contains a sequence of various Pleistocene lacustrine deposits associated with higher-than-today lake levels at the Dead Sea basin. In addition it contains Chalcolithic remains and 5th century BC burials attributed to the Persian period, cemented and covered by Late Holocene travertine flowstone. These deposits represent a chain of Late Pleistocene and Holocene interconnected environmental and human events, echoing broader scale regional and global climate events. A major shift between depositional environments is associated with the rapid fall of Lake Lisan level during the latest Pleistocene. This exposed the sediments, providing for cave formation processes sometime between the latest Pleistocene (ca. 15 ka) and the Middle Holocene (ca. 4500 BC), eventually leading to human use of the cave. The Chalcolithic use of the cave can be related to a relatively moist desert environment, probably related to a shift in the location of the northern boundary of the Saharo-Arabian desert belt. The travertine layer was U-Th dated 2.46 ± 0.10 to 2.10 ± 0.04 ka, in agreement with the archaeological finds from the Persian period. Together with the inner consistency of the dating results, this strongly supports the reliability of the radiometric ages. The 2.46-2.10 ka travertine deposition within the presently dry cave suggests a higher recharge of the Judean Desert aquifer, correlative to a rising Dead Sea towards the end of the 1st millennium BC. This suggests a relatively moist local and regional climate facilitating human habitation of the desert.     

山东高青县胥家村南遗址北朝至隋唐时期人群的生存压力分析

本研究从胥家村南遗址入手, 试图探讨我国古人群生存压力水平、不同生业模式下古人群的生存压力变化以及不同生存压力指标之间是否存在显著相关性。因此, 选取我国黄河中下游地区不同时期18处遗址的古人群, 将这些人群的牙釉质发育不全、多孔性骨肥厚、眶顶板筛孔样变及骨膜炎4种生存压力指标的个体患病率进行对比研究及相关性检验。胥家村南遗址位于山东省淄博市高青县, 该遗址共发现北朝至隋唐时期人骨22例。从生存压力水平上看, 该人群龋病、牙釉质发育不全、牙周炎、多孔性骨肥厚及骨膜炎的出现率分别为53.85%、76.92%、15.38%、20.00%、94.74%, 其中牙釉质发育不全与骨膜炎的患病率远高于同时期其他人群, 表明该人群承受着较大的生存压力, 属于营养健康状况较为低下的农业人群。经对比研究发现, 牙釉质发育不全患病率随着时间的推移呈现明显上升趋势, 或许暗示着我国古人群的生存压力随着农业发展水平的提升逐渐增大, 营养水平和健康状况逐渐下降; 多孔性骨肥厚及骨膜炎患病率随时代改变无明显变化; 眶顶板筛孔样变患病率随着时间推移整体上呈下降趋势但变化幅度较小。不同生业模式下的古人群多孔性骨肥厚及眶顶板筛孔样变患病率并不存在显著差异, 这说明或许饮食结构并非引发贫血的最主要原因。经斯皮尔曼相关系数检验可知, 骨膜炎与贫血之间无显著相关性, 而与牙釉质发育不全关系密切。

     

安徽阜南台家寺遗址出土龟甲的C、N稳定同位素分析

本研究以阜南台家寺遗址出土的商代龟甲及部分动物骨骼为材料,开展了C、N稳定同位素分析,在揭示动物食物结构的基础上初步探讨了先民对龟的使用及龟的来源问题。研究结果显示：龟甲的同位素数据相互之间差异较大,通过聚类分析大致可分为三类：第一类是高δ13C和高δ15N值（δ13C=-20.3 ‰ ±0.4 ‰,n=3;δ15N=7.8 ‰ ±0.2 ‰,n=3）;第二类是δ13C值居中,δ15N值偏低（δ13C=-21.6 ‰ ±0.4 ‰,n=4;δ15N=7.0 ‰ ±0.3 ‰,n=4）;第三类是δ13C值偏低、δ15N值居中（δ13C=-23.7 ‰ ±0.6 ‰,n=4;δ15N=7.6 ‰ ±0.3 ‰,n=4）,这意味着该遗址出土的龟甲可能存在多种来源。究其原因,可能缘于先民制作卜甲时使用的龟来源于不同的栖息环境,抑或来源于不同种属的龟。这种用龟行为,或许与殷墟甲骨上记载的"贡龟"密切相关。尽管本研究通过稳定同位素分析揭示商代先民的用龟行为尚属初步,但毋庸置疑,本研究为全面探索商代先民的用龟行为、拓展甲骨学的研究领域提供了新的研究证据和视角。     

The effects of attenuation and site on the spectra of microearthquakes in the Jubilee Hills region of Hyderabad,India

Microearthquake spectra from Jubilee Hills, Hyderabad are analyzed to observe the effect of attenuation and site on these spectra. The ratios of spectral amplitudes at lower and higher frequency are measured for three different stations at varying epicentral distances to estimate Q value for both P-and S-wave in near and sub-surface layer. Average estimates of Qp and Qs are 235 and 278 respectively. Value of Qs/Qp larger than 1.0 suggests dry crust for most of the Jubilee Hills region. The near-surface low Qp and Qs for 0 km to 0.9 km depth coincide with the soil layer, top and semi-weathered and highly fractured zone. In contrast, at a shallower depth beneath the Jubilee Hills area, Hyderabad, we obtain high Qp and Qs zone, which corresponds to the dense and high velocity rocks of the region. The varying corner frequencies for these spectra are inferred to be characteristics of site. Comparisons of disparity in spectral content with reference to hard rock site conclude that lithology of the northwest part of Jubilee Hills area amplify about twice the incoming seismic signal, as compared to the southern part best outlined at 8 to 10 Hz only.     

新石器时代晚期凉山地区粟黍农业初探——来自河东田、河头地遗址先民骨骼生物磷灰石的稳定同位素证据

中国西南地区是新石器时代粟黍向外传播、发展的重要交流通道,然而该区域粟黍南传的具体过程和路线尚不明确。鉴于此,本研究对四川凉山地区河东田遗址（26°10'7.78″N,102°6'51.83″E）和河头地遗址（26°10'25.20″N,102°6'54.84″E）先民骨骼生物磷灰石进行了碳、氧稳定同位素分析,以探讨凉山地区先民的生存策略以及粟黍在该地区的传播。河东田遗址和河头地遗址共获取了6例人骨生物磷灰石的有效数据,其δ¹³C均值分别为-5.5‰±1.8‰（n=4）,-5.5‰（n=2,-6.9‰和-4.0‰）,结果显示该区域人群的饮食呈现为兼具C₃和C₄类食物的混合食物结构,且粟黍等C₄类食物在本地区先民的食物结构中具有重要的贡献;河东田遗址和河头地遗址先民的δ¹⁸O均值分别为-12.3‰±0.4‰（n=4）,-12.0‰（n=2,-12.0‰和-11.9‰）,显示两处遗址先民摄入的水分来源相对一致,当时的先民可能是在本地生活,围绕城河定居。在此基础上,结合中国西南地区同时期稳定同位素数据和其他考古研究发现新石器时代晚期凉山地区的粟作农业应当是当地自然环境和考古学文化互动双重影响的结果,粟黍可能传播至凉山地区后继续南传至云南乃至东南亚地区。

     

The influence of particles recycling on the geochemistry of sediments in a large tropical dam lake in the Amazonian region,Brazil

As a result of over-erosion of soils, the fine particles, which contain the majority of nutrients, are easily washed away from soils, which become deficient in a host of components, accumulating in lakes. On one hand, the accumulation of nutrients-rich sediments are a problem, as they affect the quality of the overlying water and decrease the water storage capacity of the system; on the other hand, sediments may constitute an important resource, as they are often extremely rich in organic and inorganic nutrients in readily available forms. In the framework of an extensive work on the use of rock related materials to enhance the fertility of impoverish soils, this study aimed to evaluate the role on the nutrients cycle, of particles recycling processes from the watershed to the bottom of a large dam reservoir, at a wet tropical region under high weathering conditions. The study focus on the mineralogical transformations that clay particles undergo from the soils of the drainage basin to their final deposition within the reservoir and their influence in terms of the geochemical characteristics of sediments. We studied the bottom sediments that accumulate in two distinct seasonal periods in Tucuruí reservoir, located in the Amazonian Basin, Brazil, and soils from its drainage basin. The surface layers of sediments in twenty sampling points with variable depths, are representative of the different morphological sections of the reservoir. Nineteen soil samples, representing the main soil classes, were collected near the margins of the reservoir. Sediments and soils were subjected to the same array of physical, mineralogical and geochemical analyses: (1) texture, (2) characterization and semi-quantification of the clay fraction mineralogy and (3) geochemical analysis of the total concentration of major elements, organic compounds (organic C and nitrogen), soluble fractions of nutrients (P and K), exchangeable fractions (cation exchange capacity, exchangeable bases and acidity) and pH(H₂O).There is a remarkable homogeneity in the sedimentary distribution along the reservoir in terms of the texture and mineralogy of the clay fraction and of the chemistry of the total, soluble and exchangeable phases. These observations contrast with the physical, morphological and chemical heterogeneity of the soils and the setting lithology. Most of the sediments has a higher contribution of fine-grained material and the mineralogy of the clay fraction is dominated by kaolinite in soils and kaolinite and illite in sediments, followed by lesser amounts of gibbsite, goethite, and metahaloisite and by small/vestigial contents of chlorite and smectite. The sediments are mainly inherited from the watershed but there exist marked differences between the accumulated sediments and their parent materials. These differences mainly come from the selective erosion of fine-grained particles and the extreme climatic conditions which enhance complex transformations of mineralogical and chemical nature. Compared with the parental soils, the reservoir sediments show the following differences: (1) enrichment in fine-grained and less dense inorganic particles, (2) aggradative mineralogical transformations, including enrichment in clay minerals with higher cationic adsorption and exchange capacity, (3) degradation of the crystalline structure of Fe- and Al-oxides (goethite, gibbsite), (4) increase in easily leached elements (Mg, Ca, P, K, Na) and decrease in chemically less mobile elements (Si, Fe) and (5) higher contents of organic carbon, nitrogen, and soluble forms of P and K, mainly concentrated in the clay fraction. These transformations are extremely important in the nutrients cycle, denoting that sediments represent an efficient sink for nutrients from the over-erosion of soils. Mineral and organic compounds can permanently or temporarily sequester these nutrients, recycling them and enhancing their availability through the slow release of components from relatively loose crystal structures. These processes can easily explain the enrichment in soluble and exchangeable forms of elements such as P, K, Ca or Mg. This study conclude that the particles recycling in a large tropical dam reservoir which receives high fluxes of allochthonous nutrients, has an important role in the good quality of sediments for agricultural use and in the profitable use of this technology to recover depleted soils in remediation projects in regions near large hydroelectric plants.     

Geochemical and mineralogical investigation of domestic archaeological soil features at the Tiel-Passewaaij site,The Netherlands

Archaeological soil features can be defined as areas of staining in ancient cultural soil horizons and are frequently used in surveys to locate sites and activity areas. Visual observation of these features, however, provides only limited information on their origin and the processes leading to their formation and this limits site interpretation. This paper presents the results of geochemical and mineralogical analyses of domestic archaeological soil features in order to assess their composition, formation pathway and origin. The greenish soil features studied here belong to a house plan from a Roman farmhouse located at the Tiel-Passewaaij site in the Netherlands. The soils were investigated using a range of techniques, including X-ray Fluorescence (XRF) spectroscopy, sequential soil extractions, Fourier-transformed infrared (FT-IR) spectroscopy, X-ray Diffraction (XRD) and microprobe analysis. The results indicate that the studied soil features can chemically be distinguished from off-site soils e.g. based on their phosphate and carbonate content. Mineralogical analysis of aggregate samples from soil features further reveal that quartz and feldspar minerals are coated with Ca–Fe–P phases that closely resemble anapaite and mitridatite mineral forms. The formation of these mineral phases probably resulted from periodic reductive dissolution of Fe-oxide phases and subsequent precipitation of Fe–P phases, with inclusion of Ca from anthropogenic carbonates or groundwater. The combined presence of (Ca)-carbonates, P-phases and some anthropogenic trace elements (Cu, Zn) suggests that the greenish soil features stem from manure inputs.     

The new 14C chronology for the Palaeolithic site of La Ferrassie,France: the disappearance of Neanderthals and the arrival of Homo sapiens in France

The grand abri at La Ferrassie (France) has been a key site for Palaeolithic research since the early part of the 20th century. It became the eponymous site for one variant of Middle Palaeolithic stone tools, and its sequence was used to define stages of the Aurignacian, an early phase of the Upper Palaeolithic. Several Neanderthal remains, including two relatively intact skeletons, make it one of the most important sites for the study of Neanderthal morphology and one of the more important data sets when discussing the Neanderthal treatment of the dead. However, the site has remained essentially undated. Our goal here is to provide a robust chronological framework of the La Ferrassie sequence to be used for broad regional models about human behaviour during the late Middle to Upper Palaeolithic periods. To achieve this goal, we used a combination of modern excavation methods, extensive geoarchaeological analyses, and radiocarbon dating. If we accept that Neanderthals were responsible for the Châtelperronian, then our results suggest an overlap of ca. 1600 years with the newly arrived Homo sapiens found elsewhere in France.     

优势相分析在白家海—五彩湾地区苍房沟群沉积相分析中的应用

在白家海—五彩湾地区苍房沟群沉积相分析中建立了优势相的划分标准,同时得出上苍房沟群的优势相为冲积扇—辫状河和曲流河,下苍房沟群的优势相为扇三角洲、滨浅湖和曲流河等。综合优势相分析和地震资料进行了沉积相的平面展布。     

毕节市北部岩溶地下水水化学特征及影响因素的多元统计分析

本文利用层次聚类分析和因子分析两种多元统计方法探讨了贵州省毕节市岩溶地下水水化学组分特征及影响因素。结果表明:研究区地下水组分浓度变化范围较大,具有明显的空间变异性,其受到地理因素、水岩作用过程、土壤等自然因素、人类活动的影响。这四个影响因素能够解释地下水水化学组分82%的特征,其中,水岩作用过程和人类活动是主要影响因素。地下水中HCO3-、SO42-、Ca2+和Mg2+主要来源于碳酸盐岩矿物的溶解,同时也受到人类采煤活动的影响;Cl-、K+、Na+和NO3-则主要受到人类活动,特别是农业化肥、粪肥、农药施用和生活污水排放等因素的影响。本研究有助于深化对西南岩溶地下水水化学特征的理解,有助于有效预测岩溶地下水污染物来源,且对岩溶区水资源的合理开发利用具有积极的指导意义。