A side-scan sonar and high-resolution Chirp sub-bottom profile study of the natural and anthropogenic sedimentary record of Lower Lough Erne,northwestern Ireland

A geophysical survey (side-scan sonar and high-resolution sub-bottom profiling) combined with established chrono- and bio-stratigraphic markers are used to reconstruct the evolutionary history of Lower Lough Erne, northwestern Ireland since the end of the last glacial. Discrete acoustic units define four prominent sedimentation cycles, one Late-glacial and three Holocene, within the seismic stratigraphy. Basin development is predominantly controlled by climate until the Mid Holocene when the effects of cultural activity are related to pronounced signatures in the seismic record. An enhanced reflector marking the termination of the Early Holocene sedimentation cycle is associated with the elm decline and forest clearance during the Neolithic (between approximately 5800 cal. BP and 5300 cal. BP). The associated increase in sediment input, by infilling minor topographic lows and basins, has a smoothing effect on the morphologic expression of the original basin. Onlapping and truncated reflectors in the penultimate acoustic unit define further modification of lake bed relief by removal of sediment from the system during engineered lowering of the lake levels that began in the 1880s. Acoustic anomalies identified on the side-scan sonar data are linked with cultural activity and are identified as having the potential to facilitate the recent establishment and migration of invasive zebra mussels through the Erne system.     

Human occupation of South Eastern Altai highlands (Russia) in the context of environmental changes

Multidisciplinary investigations including geomorphological and geoarchaeological approaches, litho-stratigraphic and pedogenetic analysis accompanied by radiocarbon dating show the contrasting human environmental changes within the highlands of the Russian Altai since the late Paleolithic. Radiocarbon ages of fossil soils formed at 1,475–1,730 m a.s.l. indicate draining of the ice-dammed lake in the Kurai basin before the beginning of the Holocene and disintegration of the Chuya lake into several shallow but quite spacious reservoirs by 8,223?±?181 cal. BP. Using archaeological sites as spatio-temporal markers allows reconstructions to be specified based on geological data. Archaeological site distribution in the Chuya valley between the Chuya and Kurai basins indicates that all cataclysmic flood events related to the Holocene hydrological changes occurred before the Scythian epoch. Due to the redeposition of most Paleolithic finds in the region, they should be carefully examined before they are utilized for any reconstructions. Using fossil and contemporary soils as an independent informative climatic proxy archive supports the conception of generally more humid and warmer climate conditions in the first half of the Holocene within the SE Altai and a more arid and cold climate in the second one. The repeated climate deteriorations that caused glacier expansion and the progressive aridity intensification in the region along with the sociopolitical reasons are the major factors that controlled the habitat of nomadic communities and cultures shifting within the SE Altai in the second half of the Holocene. Anthropogenic impact together with the progressive aridization led to the deforestation of the eastern part of the Chuya depression.     

Combining pollen and charcoal: evaluating Holocene vegetation composition and dynamics

Pollen analysis reveals vegetation change on a local and regional level over (ideally) continuous time spans but with complications when it comes to the reconstruction of spatially precise species occurrence and composition. Wood charcoal analysis provides site-related information on species occurrence and woodland composition, especially when sediments containing pollen are lacking, but is normally discontinuously available and has the danger of human bias due to potential selection of certain species for e.g. fire making, house construction or charcoal making. Combining the two methods – assuming that suitable palaeoarchives are neighbouring – might compensate for their disadvantages and strengthen the interpretations on vegetation composition and dynamics on a local, extra-local and regional scale. Three examples are given where pollen analysis from “classical” archives – mires and lake sediments – was carried out, and where additionally species identification of wood charcoals was done on samples extracted from close-by archives. The first example (Kugelstattmoos, Bavarian Forest, Germany) combines a Holocene pollen diagram derived from a small mire with late medieval/early modern times charcoal spectra from charcoal production sites which are situated on the margin of the mire. Results show the local occurrence of the main woodland species Fagus sylvatica and Abies alba, and raises new questions on the montane species composition of the formerly natural forests in the Bavarian Forest. The second example (Bargstedter Moor, Schleswig-Holstein, Germany) combines Holocene pollen diagrams from a peat bog with late medieval/early modern times charcoal spectra from charcoal production sites in a woodland close to the bog. It shows the role of Quercus, Fagus, Alnus and Carpinus in medieval and early modern times woodlands and its use by man. The third example (Kleiner Tornowsee, Brandenburg, Germany) combines pollen data from sediments of a small lake with charcoal data derived from Holocene colluvisols and soils. The examples show that anthracological and palynological data complement one another to create a more detailed picture of woodland history and landscape change than one method alone would provide.     

The Key Role of Water Resources Management in Ecological Restoration in Western China

The interactions of nature and society are intimately reflected in the degradation of the vast, yet diverse, landscapes and ecosystems of arid western China. The development of agriculture, especially irrigation, has altered rivers, soils and ecosystems so much that major ecological rehabilitation and restoration efforts have been needed since 1950. The catchments of the Tarim River in southern Xinjiang (the Tarim Basin) and of the Black River (Hei He) in Gansu Province and western Inner Mongolia provide examples of the benefits, difficulties and conflicts involved in dryland water management. In the early stages of the human development of these catchments, agriculture depending on irrigation using water from these inland rivers was encouraged. The over‐exploitation of these water resources led to such ecological problems as desiccation of lakes, drying out of rivers, degradation of soils and vegetation and lowering of groundwater levels, with consequent environmental and economic impacts. Since 1990 several high‐cost, national projects to re‐establish ecosystems have been initiated. Water is now released from dams in the headwaters of the rivers in order to restore water flows to the dried out lake basins. Such schemes have inevitably led to social problems and difficulties for the people who depended on the water from the dams for local irrigation. The contrasts in adjustments and attitudes over the use of water for agriculture and other economic activities, as opposed to schemes of restoration of ecosystems and ecological engineering, stem largely from two issues; inconsistent provision of information from the scientific community, and differing ideologies, namely environmental protection versus economic development.     

Modern and early-middle Holocene shells of the freshwater mollusc Unio, from Çatalhöyük in the Konya Basin, Turkey: preliminary palaeoclimatic implications from molluscan isotope data

Carbon and oxygen isotope ratios in the shells of the freshwater Unio mollusc yield information on the isotopic composition of the water in which the shell was formed, which in turn relates to climatic conditions prevailing during the bivalves’ life span. Here we analysed shells from one modern Unio, from a modern lake shore in Anatolia, and 4 subfossil Unio shells from Çatalhöyük (dated between 7200 BC and 5000 BC, Neolithic and Chalcolithic periods). Sequential carbon and oxygen isotope analysis along the surface of the shells provides information on seasonal or shorter-term variability of lake waters during the lifetime of the organisms. δ¹⁸O values of the modern shell are consistent with it being collected from a dammed portion of the Seyhan River that does not undergo intensive summer evaporation. This is in contrast to many of the surface water bodies in Anatolia which suffer extensive evaporation in the arid summers. δ¹⁸O values of the subfossil shells from the Çatalhöyük middens indicate that the bivalves came from lakes which evaporated extensively during the summer months but were replenished by high winter rainfall, suggesting that the subfossil shells lived in relatively small lakes or ponds. Stable isotope analysis along the growth of freshwater bivalves is one of the few methods for investigating seasonal water fluctuations in the past. These results may alter current interpretations on the environment of Çatalhöyük during the Neolithic, although more work is needed to confirm these initial findings.     

Fluids and halogens at the diagenetic–metamorphic boundary: evidence from veins in continental basins, western Norway

Seven vein types are recognized in three continental Devonian molasse basins (the Hornelen, Kvamshesten and Solund basins) in western Norway. These include calcite‐, quartz‐ and epidote‐dominated veins. The salinities of fluid inclusions from quartz‐dominated veins in the Hornelen and Kvamshesten basins are close to or slightly higher than those for modern seawater, whereas the fluids from quartz‐ and calcite‐dominated veins in the Solund basin range from seawater values to 20 wt % NaCl equivalent. Minerals such as biotite, amphibole, titanite, chlorite and epidote are abundant in the latter veins, and are important constituents of the authigenic mineral assemblages. A combination of fluid inclusion and petrological data suggest that at least some of the veins formed at depths around 12–14 km. The Cl/Br ratios and the salinity of the fluid inclusions can be explained by interactions with evaporites, implying that the sedimentary environment forming the basin fill had the strongest influence upon low‐grade metamorphic fluid Cl and Br contents. Differences in the Cl/I and Na/Br ratios between the Solund basin and the Hornelen and Kvamshesten basins are best explained by local mass transfer between pore fluids and the surrounding rock matrix during burial and increasing temperatures.     

The distribution and morphometry of lakes and reservoirs in British Columbia: a provincial inventory

An inventory of provincial lakes and reservoirs has been developed to characterise and assess the distribution and morphometry of standing water bodies in British Columbia. In the province, there are over 241,500 lakes and reservoirs greater than 1,000 m ² in size. These water bodies cover 2.37 percent of the province area and contain an estimated 521 km ³ of water (312 km ³ in natural lakes and 209 km ³ in reservoirs). A hypsometric relation suitable for order-of-magnitude estimates of lake volume from lake area is presented. Based on the distribution and morphometric attributes of lakes, several distinctive limnologic regions were identified, including the northeastern Alberta Plateau (highest proportion of circular lakes), the southwestern Alberta Plateau (lowest lake density/coverage and highest proportion of irregularly shaped lakes) and the Milbanke Strandflat (highest density of lakes). Observed regional and scale-related patterns in lake distribution/morphometry appear to be largely related to geomorphic controls, particularly tectonic and glacial history. Large-scale hydrologic implications of these standing water bodies and potential ecosystem/water resource management applications of the provincial inventory are also discussed.     

Geoarchaeology at Gi,a middle stone age and later stone age site in the Northwest Kalahari

Gi with sealed middle stone age and later stone age occurrences is located in the Dobe Valley along the Botswana-Namibia border. The phases of middle stone age settlement were linked to a semiarid streamway during the early Upper Pleistocene. A major humid interval followed, when a large lake was ponded in the Dobe Valley. Later stone age settlement appeared after this lake disappeared and was replaced by a mosaic of pans (ephemeral lakes). Subsequently, another period of humid environment favoured another valley-wide lake during the late Upper Pleistocene. Later stone age settlement resumed when this second lake deteriorated into the modern pan terrains of the Dobe Valley. In total, the Gi beds record multiple environmental changes both more humid and more arid than present during the Upper Pleistocene and Holocene, as well as a variable array of adaptive opportunities for prehistoric settlement.     

Late Quaternary ostracods from Lake George,New South Wales

Fossil ostracods from the uppermost 3m of core LG4 from Lake George all have modern living representatives. This part of the core is thought to represent deposition during the last 60,000 years (see Singh et al., 1981b) and the lake hisotry is traced from a knowledge of the ostracod ecology.

The following distinct phases, and their respective timing, are postulated for Lake George (the timing of events should be considered with caution as few ¹⁴C dates are available): water fresh and lake full for the periods of 10,200 – 12,000 yBP and 19,100 – 20,700 yBP, water fresh, ephemeral at times, for the periods of 3,200–4,000 yBP, 7,000 yBP, 7,500 yBP, 8,500–10,200 yBP, 12,000–13,500 yBP, 20,700–23,500 yBP, 23,800–27,600 yBP and at some stage between 27,000 and 60,000 yBP; ephemeral saline water for a few short episodes between 3,200 and 4,000 yBP and for the periods of 15,600–17,400 yBP and 23,800–27,600 yBP; lake definitely dry between 17,400 and 19,100 yBP.

Data obtained from the ostracods correlate reasonably well with those of lake level fluctuations based on the study of ancient shorelines by Coventry (1976) and others based on facies analyses and the record of plant microfossils by Singh et al. (1981b).     

Mineral weathering in forest soils and its relevance to the preservation of the buried archaeological resource

There is more woodland in Britain now than for many centuries and considering many international climate change mitigation policies, woodland cover, both in Britain and internationally, is being promoted. However, neither the management of existing woodlands nor their expansion should be at the expense of important archaeological evidence. Due to the large number of known archaeological sites, the large areas of land with uninvestigated archaeological potential and the expanding woodland cover, suitable mitigation strategies need to be developed to allow preservation in situ of important sites. An understanding of how woodland soils and the buried archaeological resource interact is, therefore, essential. This paper utilises ongoing environmental research into the mineral weathering rates in forest soils and considers its application to artefact preservation. The study concludes that soil water pH, its movement, and the saturation of dissolved ions in the soil solution are major factors determining both mineral and artefact longevity. A simple guide to artefact longevity based on these properties is proposed and a geochemical model for predicting loss is tested. These tools could be applied to any soil or individual horizon irrespective of land-use.     

The Retreat of the North American Ice Sheet and Shifts in Cyclone Tracks

The alternating retreats and readvances of the North American ice sheet from 18,000 years to 6000 years ago are attributed to shifts in storm tracks. According to the author's theory, proglacial lakes formed during the retreat of the ice sheet became the paths of cyclone tracks whose precipitation led to an accumulation of ice and a readvance of the ice sheet. The readvance into the proglacial lake basins resulted in a reduction or southward shift of cyclone tracks, and this in turn led to a halt of the readvance and a retreat of the ice sheet. As soon as the ice had vacated the Great Lakes basin, the cyclone tracks would once again shift northward and the process of readvance would start all over again.     

Exploring Diversity in Household Pottery Traditions in Crusader Greece: a Case Study from the City of Thebes,Boeotia

This paper provides new data on an under‐documented topic in Aegean archaeology, that of the impact of Latin–Greek cohabitation on craftsmanship, socio‐economic organization and household pottery traditions. The chosen approach is a petrographic study of the provenance and technology of 37 cooking pots, jugs, basins and storage jars from the city of Thebes, Boeotia. The ceramics span from the late 12th to the mid‐14th century and thereby cover the periods of Byzantine, Frankish and Catalan control over the city. The analysis indicates that most pottery products were not locally made during these periods. Pottery consumption at Thebes involved, in the 12th/13th century, regional products from northern Boeotia, while pottery supplies from Euboea that had developed under Byzantine rule continued into the 14th century, well after Boeotia and Euboea came into the hands of, respectively, Frankish and Venetian lords in the aftermath of the Fourth Crusade (1204). The petrographic analysis also allows for the characterization of Byzantine and Latin tempering practices of the pottery fabrics. These results highlight phenomena of regional economic reliance in central Greece and provide rare evidence for the cross‐cultural diffusion of technological knowledge in the late medieval Mediterranean.     

Holocene lakes and prehistoric settlements of the Western Faiyum,Egypt

Holocene lake stages in the Faiyum depression commenced with a high lake stand during the 10th millennium bp, followed by an early Holocene lake from 8500 to 7000 bp. A pronounced recession and the development of a palaeosol preceded another rise to a mid-Holocene, high lake level from 6500 to 5100 bp. A major drop in level coincided with the late Neolithic and Early Dynastic. The Moeris lake witnessed by Herodotus is also documented. The drop in lake level during early Ptolemaic times marked the end of the freshwater lake and was apparently, in part, a result of declining Nile floods. Terminal Palaeolithic sites are associated with the early Holocene lake and Neolithic sites with the mid-Holocene phase. Prehistoric settlements were placed near lake-margin marshes and ponds. The richness of the lake margin in aquatic resources and its susceptibility to short- and long-term fluctuations influenced both subsistence and settlements, and is believed to have encouraged a para-agricultural economy.     

基于机器学习和图像形态学的彩色近代地图数字化——以近代上海地区地表水体信息提取为例

利用科学测绘技术绘制的近代地图作为一类珍贵的历史地理资料,不同程度上反映着过去的地表覆盖情况,数字化则是复原地图所载地表覆盖信息的重要途径。以《华东·上海》地图为例,实现并验证一种基于机器学习和图像形态学的彩色近代地图数字化方法。结果表明,该方法能够充分挖掘地图中的颜色信息和形态结构信息,以半自动方式快速准确地将彩色近代地图中的地表水体信息提取出来。该方法对数字化一类彩色近代地图具有参考价值,有望为精准复原近代以来地表覆盖变迁,深入理解人地关系变化提供数据和方法基础。     

西安地区全新世土壤的演变

野外调查和室内实验资料表明 ,西安临潼全新世发育了 4层土壤。其中有两层发育在较温湿的气候条件下 ,两层发育在较冷干的气候条件下。温湿条件下发育的土壤为棕色土与淋溶褐土 ,冷干条件下发育的土壤为典型褐土与粘化黑垆土。临潼与长安全新世土壤结构及粒度成分指示 ,自全新世中期的大暖期以来 ,西安地区气候环境呈明显的变干趋势。     

Bangalore Lake story: reflections on the spirit of a place

This article is based on an ethnographic case study conducted during a small project on the public-private development of lakes in Bangalore. Using conceptualizations of place and implacement as developed by scholars such as Casey and Anderson, this article unpacks the relationship between sociopolitical processes and modification of landscape during the implementation of a public–private partnership lake development project of Hebbal Lake. The disappearance of designated places along the lakeshore that are accessible to different users tends to favor a monoculture of consumer experiences, which can be seen as a hidden form of displacement of other users. I suggest that by physically modifying the “places” on the lakeshore that once supported multiple human-geographical interactions, certain people can experience displacement even if they are allowed to access the lake.     

Lake levels,mobility and lithic raw material selection and reduction strategies: A Great Lakes case study

Abstract

It has recently been proposed that lowered lake levels after 4250 BP broadened opportunities for mobility and interaction patterns among hunter-gatherer populations in the Saginaw drainage and in Michigan more broadly (; ). Here, data are presented on chipped stone reduction strategies as reflected in two site assemblages in Bay City, Michigan (20BY28, 20BY387) that bridge this key point in time. The earliest Late Archaic components of these sites, occupied during the higher than modern post Nipissing recession ca. 3200 BP, are typified by on-site reduction of local cherts, often utilising a bipolar reduction strategy. Subsequent uses of the area largely shifted to lower elevations. The more recent site components contain both more diverse projectile styles, many of which can be linked with Ontario types, and higher occurrences of non-local raw materials, specifically Onondaga chert apparently arriving at the site as preforms. The last use of these sites occurred during the Late Woodland, also during lower water levels approaching modern, and reflecting the highest use of Onondaga chert. We suggest that these changes resulted from shifting mobility and exchange patterns, facilitated in part by lowered post Nipissing water levels.     

A Geomorphic and Environmental Evaluation of the Hula Drainage Project,Israel

The drainage of Lake Hula and its swamps in the 1950s created a new landform and changed the hydrological and sedimentological regime in the Hula valley. The affected area extended over 40 km² and the work basically improved the drainage conditions of another 20 km² that were periodically affected by flooding. This man‐made project marked the termination of one of the oldest documented lakes and surrounding wetlands in history, with a rich and diverse aquatic biota. The reclaimed swampy land started to settle immediately upon drainage, mainly due to the compaction of the peat layers. The mean yearly settling rate was 8 cm yr^–1. Agricultural development of the reclaimed land was unsuccessful, and soils were affected by continuous underground fires. Weathered peat soils, without a vegetation cover, were eroded by wind. Another ecological effect was the release of nutrients by the decomposing peat, with the nutrients carried by the Jordan river floods into the eutrophic Lake Kinneret. To prevent the natural subsidence a small shallow lake, 110 ha in area, and a network of canals were created in the 1990s. This new wetland and the adjacent agricultural areas are the targets of a multidisciplinary monitoring program. An eco‐tourism development project is currently being planned. Almost 50 years after starting the drainage project the present trend is to restore at least a small fragment of the previous landscape and ecosystem.     

Age and the palaeoenvironment of the West Ukrainian palaeolithic: the case of Velykyi Glybochok multi-cultural site

The Velykyi Glybochok Palaeolithic site near Ternopil town (Podolia Upland) contains a set of cultural layers in a sequence of loess and fossil soils. Beside the archaeological study of stone assemblages, the profile was investigated using lithological, palaeopedological and geochemical methods, including stable carbon and oxygen isotopes composition of pedogenic carbonates, soils micromorphology and TL dating. Remnants of vertebrates' bones and mollusc shells were also distinguished. The oldest cultural layer III documented the presence of Palaeolithic people during the Penultimate Interglacial represented by fossil soil – cambisol in type, developed under dense vegetation cover. The cultural layer III B is connected with initial cambisol originated in a short period of open landscape vegetation with shrubs development, dated to the climatic amelioration during the time of Penultimate Glaciation. The Last Interglacial is represented by luvisol formation with two stages of illuviation, which shows forest type of vegetation. Materials of the cultural layer III A were dispersed in the soil irregularly and mixed with artifacts of cultural layer II. Artifacts of III, III A and III B cultural layers represent the Middle Palaeolithic “Dniesterian Mousterian culture with Levalloisian technique”. These of assemblage II represent the Upper Palaeolithic. Inside the recent soil at the top of the sequence, the Mesolithic cultural layer I is present. Velykyi Glybochok is the only multilayer site in Podolia with detailed information about geological position of particular cultural layers.     

Modeling thermal convection in supradetachment basins: example from western Norway

The juxtaposition of fault‐bounded sedimentary basins, above crustal‐scale detachments, with warmer exhumed footwalls can lead to thermal convection of the fluids in the sediments. The Devonian basins of western Norway are examples of supradetachment basins that formed in the hanging wall of the Nordfjord‐Sogn Detachment Zone. In the central part of the Hornelen and Kvamshesten basins, the basin‐fill is chiefly represented by fluvial sandstones and minor lacustrine siltstones, whereas the fault margins are dominated by fanglomerates along the detachment contact. Prominent alteration and low‐greenschist facies metamorphic conditions are associated with the peak temperature estimates of the sediments close to the detachment shear zone. Fluid circulation may have been active during the burial of the sediments, and we quantify the potential role played by thermal convection in redistributing heat within the basins. Different models are tested with homogeneous and layered basin‐fill and with material transport properties corresponding to sandstones and siltstones. We found that thermally driven fluid flow is expected in supradetachment basins as a transient process during the exhumation of warmer footwalls. We demonstrate that the fluid flow may have significantly affected the temperature distribution in the upper five kilometers of the Devonian basins of western Norway. The temperature anomaly induced by the flow may locally reach about 80°C. The sedimentary layering formed by sand‐ and siltstones strata does not inhibit fluid circulation at the scale of the basin. The presence of fluid pathways along the detachment has an important impact on the flow and allows an efficient drainage of the basin by channelizing fluids upward along the detachment.