首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Since the early 1990s, excavations of a protohistoric lakeside settlement in the Korça basin carried out by a French–Albanian archaeological team have induced geomorphological and palynological studies about the sedimentary records of Lake Maliq. These studies allow us to distinguish a series of centennial-scale high and low lake level events between 4200 and 4000 cal BP (2899–2637 BC/2843–2416 BC) and 2600 cal BP (822–671 BC), probably due to large-scale climate changes (in the Mediterranean basin). In addition, the sediment sequence also gives evidence of a millennial-scale trend of lake level rise. It appears to be an interplay between lake level rises and falls against tectonic subsidence of the basin allowing accommodation space for sediment deposition.The variations of the lake's level and the lake's surface area influenced the development and the abandonment of the nearby lakeside settlements (like the tell of Sovjan). In order to prepare an archaeological survey around the now dried up lake, we made a 3D model of the Holocene deposit from the lake including these lake level results, geomorphological mapping, excavation data, numerous core logs, AMS 14C dating and SRTM DEM data. The GIS model allowed us to propose four palaeogeographical reconstructions of the extension of Lake Maliq: around 14,000 BP, during the Mesolithic (around 9000 BP – 8781–8542 BC), the Early/Middle Bronze Age transition (around 3800 BP – 2310–2042 BC) and the Iron Age (2600 BP – 822–671 BC). A map of the thickness of the sediments above potential archaeological layers is also proposed.  相似文献   

2.
The backscatter responses of submerged archaeological material remain poorly understood. To address this, a control experiment was conducted in Belfast Lough during July and August 2001. A selection of material and targets was arranged on the seabed in varying orientations, in an attempt to replicate the situation found on a range of archaeological sites where material is exposed on the seafloor. Repeat side-scan sonar surveys of the control array were conducted at variable ranges and fish heights to examine the backscatter responses and resolution of three commercially available side-scan sonar systems. Results indicate that the electro-acoustic specification of the pulse length and the beam angle of the acoustic sources govern the theoretical resolution of side-scan data. Backscatter data from the control experiment indicate both organic (wood and leather) and inorganic (metals, ceramics, glass and varying aggregate and ballast grades) natural and man-made materials can be imaged using side-scan sonar and a wide variety of archaeological material types and concentrations may be differentiated by their backscatter responses.  相似文献   

3.
The earliest evidence of prehistoric religious practice in China found so far comes from excavations at Beifudi, about 120 km south of Beijing, in the form of votive offerings and porcelain sorcery masks dated to the period 8000–7000 yr BP. These finds are part of a rich Neolithic site located on the second river terrace on the north shore of the Yi River. This paper presents results of pollen analysis of part of a sediment profile from a depression at the edge of first terrace towards second terrace, a few hundred metres away from the main archaeological finds. A sequence of marked changes in environment occurred between 9000 cal yr BP and 6000 cal yr BP, and dating evidence suggests strong associations with the ebb and flow of human activity in the area. The first phase of activity on the site begins at around 8000 cal yr BP, towards the end of a period of relatively dry, cold environmental conditions. Between 7800 cal yr BP and 7400 cal yr BP, the first clear evidence of cereal cultivation appears in the pollen record. Rich archaeological finds occur during the same time period, suggesting local prosperity. This first phase of the Beifudi culture ends at 7300 cal yr BP, when warmer and wetter conditions are inferred and wetland areas expand, reducing the area available for crop cultivation near the site. A return to drier and cooler conditions from 6900 cal yr BP corresponds with the second phase of apparent prosperity in the archaeological record from Beifudi. This phase ends at around 6500 cal yr BP, at the start of another shift towards wetter conditions in the flood plain environment. The pollen record suggests that environmental conditions in the flood plain were a major determinant of human activity at Beifudi in the early-mid Holocene.  相似文献   

4.
Whitianga Harbour on the Coromandel Peninsula, North Island, New Zealand is fronted by a broad sandy barrier composed of linear beach ridges. The barrier developed through a process of rollover as sea level rose in the early Holocene with shelly sandy sediment washed inland over estuarine muds. These overwash deposits are present to 3 m below sea level in the back barrier area. Once sea level stabilised and barrier rollover had ceased the barrier continued to prograde in a series of beach ridges. The back barrier area is characterised by estuarine muds, overlain by splay and overwash deposits that are reworked by fluvial and tidal channels. The initial flooding of the estuary occurred at around 7350–7225 years cal BP, reaching modern levels by 6894–6729 years cal BP at the earliest. Infill was rapid as evidenced by estuarine species (crustaceans and bivalves) preserved in life position. From ~6000 years BP to present, the estuary is characterised by tidal and fluvial reworking, suggesting that modern sediment inputs are bypassing the estuary.  相似文献   

5.
Tyre's ancient northern harbour has been a source of scientific intrigue and debate for many centuries. Today an insignificant fishing harbour, looking north and sheltered from the dominant winds by a sandstone reef system, is all that remains of the famous Bronze Age, Phoenician, Hellenistic, Roman and Byzantine anchorage havens. In light of this many scholars have long questioned whether the modern port corresponds to its counterpart in antiquity. Here, we provide litho- and biostratigraphical evidence for an ancient harbour approximately twice as large as the present, comprising the modern day harbour and city centre. Four distinct sedimentary units have been identified, translating the different Holocene palaeoenvironments: (1) The Holocene transgressive contact is dated ca. 7800 BP, and lies at the base of a silty-clay lithodependant unit. Our proxies are consistent with a low energy, lagoonal type environment, protected by an extensive reef system. (2) Transition to a coarse sand fraction after ca. 5500 BP is concomitant with the accretion of a semi-protected pocket beach. This environment served as a proto-harbour during the Middle Bronze Age (MBA). (3) After the MBA, artificial harbour sedimentation is represented by a fine-grained silty-sand unit with stress on the natural biosystem. This unit attests to a closed, marine-lagoonal type environment, which existed until around 1500 BP. Dredging activity during the Roman and Byzantine periods explains the absence of 1st millennium BC strata. (4) The economic decline of the ancient city after the Byzantine period is marked by the opening of the basin to greater marine influence, with a progradation of the harbour coastline. Natural sediment infilling diminished the size of the harbour to its present dimensions, lost until now, beneath the Medieval and Modern centres.  相似文献   

6.
Abstract

An examination of the late Holocene environmental and cultural sequences of the southern Brazilian highlands indicates that the colonisation of this region by the Taquara/Itararé people is associated with the expansion of Araucaria forest resulting from the onset of wetter climatic conditions in the region, which started between around 1410 and 900 cal. yr BP. The more intense and permanent human occupation of this region is associated with the advance of Araucaria forest, which provided Taquara/Itararé groups with a newly abundant and reliable resource: Araucaria seeds. In addition, we review the evidence for landscape transformation associated with the beginning of food-production in the region. Charcoal records show that local populations may have practiced slash-and-burn agriculture at lower elevations since the beginning of the late Holocene around 4320 cal. yr BP, and continued this practice during the second part of the late Holocene.  相似文献   

7.
Abstract

The results of pollen analysis and radiocarbon dating are presented for two hyrax dung deposits from rock shelters found in the Afroalpine zone of the Bale Mountains (South-Central Ethiopia). Deposits accumulated from about 15,000 to 1500 (cal) years BP and from 7000 (cal) years BP till nowadays, respectively. Pollen spectra of the initial stages of deposit development (up to 15,000 (cal) years BP) correlate with unfavourable conditions in the Late Glacial Maximum. The African Humid Period (AHP) (15,000–5000 (cal) years BP) is registered in this palaeoecological record as well as the Younger Dryas event (about 12,500 (cal) years BP). Upward shift of Afromontane forest belt and expansion of ericoid communities at high altitudes were characteristic of the Pleistocene/Holocene transition (about 10,000 (cal) years BP). The AHP which continues around 10,000 (cal) years BP after Younger Dryas, was interrupted by a dry episode around 8200 (cal) years BP. Principal aridisation trend during the last 5000 years was observed. Presumably the first traces of human activities in this area can be shown for up about 2500 (cal) years BP.  相似文献   

8.
A set of 121 radiocarbon and OSL dates has been compiled from the Upper Dnieper River and tributary valleys, Western European Russia. Each date was attributed according to geomorphic/sedimentological events and classes of fluvial activity. Summed probability density functions for each class were used to establish phases of increasing and reducing fluvial activity. The oldest detected reduction of fluvial activity was probably due to glacial damming at LGM. Within the Holocene three palaeohydrological epochs of millennial-scale were found: (1) high activity at 12,000–8,000 cal BP marked by large river palaeochannels; (2) low activity at 8,000–3,000 cal BP marked by formation of zonal-type soils on -floodplains; short episodes of high floods occurred between 6,500—4,400 cal BP; (3) contrasting hydrological oscillations since 3,000 cal BP with periods of high floods between 3,000–2,300 (2,000) and 900–100 cal BP separated by long interval of low floods 2,300 (2,000)-900 cal BP when floodplains were not inundated — zonal-type soils were developing and permanent settlements existed on floodplains. In the last millennium, four centennial-scale intervals were found: high flooding intervals are mid-11–mid-15th century and mid-17–mid-20th century. Intervals of flood activity similar to the present-day were: mid-15–mid-17th century and since mid-19th century till present. In the context of palaeohydrological changes, discussed are selected palaeogeographic issues such as: position of the glacial boundary at LGM, role of changing amounts of river runoff in the Black Sea level changes, floodplain occupation by Early Medieval population.  相似文献   

9.
中国新石器时代文化演变动力分析   总被引:1,自引:1,他引:0  
对多年来积累的气候资料的综合分析表明:在全新世期间有两个比较明显的温暖期。它们的时间分别为8~6kaBP(校正成日历年龄大约为9~7calkaBP)和5~3kaBP(日历年龄大约为5.5~3.2calkaBP)。文化的发展很大程度上受到了环境条件的制约。在前一个温暖期的后半段(8~7calkaBP),北方旱作农业(磁山文化、大地湾文化、兴隆洼文化)发展起来。南方稻作农业要在7.0~6.0calkaBP才初具规模。而6.0~5.5calkaBP的气候冷干事件使得南北方文化均有不同程度的衰退,但是南方受到的影响要小于北方。在后一个温暖期到来之后(5.5~3.2calkaBP),分别以龙山文化和良渚文化为代表的南北方新石器文化几乎同时进入发展史上的另一个黄金时代。尽管南北方文化体系对于气候变化的响应有所差异,并且不同时期不同地域文化发展动力也不尽相同,但是从大的时空尺度上来看,我国的新石器时代发展经历了如下阶段:最早期文化萌芽阶段(10calkaBP)——早中新石器时代之间的文化相对衰退期(10~8calkaBP)——新石器时代中期的北方农业文明崛起(8~7calkaBP)——7.0~6.0calkaBP的南方稻作农业的极大发展期——6.0~5.5calkaBP的文化衰退期——新石器时代晚期(5.5~4.0calkaBP)文化的极大繁荣。其间一些大的文化演替或者转型事件的时间在各地也大致相同。说明这种大的文化演进过程还是受到了同一个信号的支配,而只有环境气候因素才可能影响到如此大的范围。  相似文献   

10.
A source-to-sink multi-proxy approach has been performed within Lake Paladru (492 m a.s.l., French Prealps) catchment and a 6-m long sediment sequence retrieved from the central lacustrine basin. The combination of minerogenic signal, specific organic markers of autochthonous and allochthonous supply and archaeological data allows the reconstruction of a continuous record of past human disturbances. Over the last 10,000 years, the lacustrine sedimentation was dominated by autochthonous carbonates and the watershed was mostly forest-covered. However, seven phases of higher accumulation rate, soil erosion, algal productivity and landscape disturbances have been identified and dated from 8400 to 7900, 6000 to 4800, 4500 to 3200, 2700 to 2050 cal BP as well as AD 350–850, AD 1250–1850 and after AD 1970. Before 5200 cal BP, soil erosion is interpreted as resulting from climatic deterioration phases towards cooler and wetter conditions. During the Mid-Late Holocene period, erosion fluxes and landscape disturbances are always associated with prehistorical and historical human activities and amplified by climatic oscillations. Such changes in human land-used led to increasing minerogenic supply and nutrients loading that affected lacustrine trophic levels, especially during the last 1600 years. In addition, organic and molecular markers document previously unknown human settlements around Lake Paladru during the Bronze and the Iron Ages.  相似文献   

11.
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.  相似文献   

12.
Rice Lake, located in the eastern Great Lakes of North America, has a high density of prehistoric (11–0.5 ka BP) terrestrial archaeological sites. It has been speculated that a large number of sites are submerged on the lakebed, as lake levels have risen >9 m since the arrival of Early Paleoindian peoples (∼11 ka BP). In order to better understand the submerged landscape and its archaeological potential, a detailed bathymetric survey and sediment-coring program was conducted across a 30-km2 area of northeastern Rice Lake. Changes in Holocene water levels and shoreline positions were reconstructed by integrating core data with a digital elevation and bathymetric model (DEBM) that accounted for differential isostatic uplift and basin sedimentation. The DEBM was used to generate a series of maps showing changes in the lake paleobathmetry and paleogeography and areas of prehistoric archaeological potential.  相似文献   

13.
Epipaleolithic/early Neolithic settlements at Qinghai Lake,western China   总被引:1,自引:0,他引:1  
Transitions from terminal Pleistocene Upper Paleolithic foraging to Holocene Neolithic farming and pastoralist economic orientations in the northern Tibetan Plateau are examined from the perspective of Epipaleolithic sites located near Qinghai Lake, Qinghai Province, western China. Jiangxigou 2 is an artifact-rich, multicomponent midden site with the main period of occupation dating ca. 9000–5000 cal yr BP, containing abundant flaked stone artifacts including a substantial proportion of microlithic tools, abundant faunal remains including gazelle, deer, and sheep, and a small number of ceramics, including the oldest known on the Tibetan Plateau. Heimahe 3, on the other hand, is a brief hunter's camp dating ca. 8450 cal yr BP, with evident affinities to late Upper Paleolithic camps in the same region that date several thousand years older. The two distinctively different sites are probably nodes within a single Epipaleolithic foraging system that developed on the margins of the high Tibetan Plateau during the early Holocene, and that served as a basis for colonization of the high-altitude Plateau at that time. Jiangxigou 2 appears to be connected to early Neolithic agricultural settlements along the upper Yellow River (Huang He) drainage during the middle Holocene, and may provide insights into forager–agriculturalist interactions that lead to the development of pastoralist systems in the region.  相似文献   

14.
Abstract

The question of the anthropic or natural origin of land snail deposits within the archaeological record is the subject of debate all over the world. In the Cantabrian region of northern Spain land snail middens are routinely identified in the early Holocene archaeological record. La Fragua Cave (Cantabria, Spain), which contains an early Holocene layer dated to 9600±140 BP (10,932±196 cal BP), offers the opportunity to address this debate through the examination of Cepaea nemoralis (Linnaeus) land snails recovered in direct association with mammal bones, charcoal, lithic artefacts and other materials. It is therefore believed that their presence at the site is clearly anthropic in origin. In addition, the exploitation patterns indicate an occasional collection and consumption of land snails, which confirms the complementary character of these resources in the diet of hunter-gatherers in Cantabrian Spain during the Pleistocene-Holocene transition.  相似文献   

15.
Excavations at the archaeological site of Encosta de Sant'Ana (Lisbon, Portugal) uncovered a mid-Holocene buried alluvial soil associated with early Neolithic occupation layers. Routine laboratory analyses and micromorphological observations were undertaken on the soil material. Humic acids from its Ab horizon, as well as Neolithic ecofacts, were radiocarbon dated. The dates obtained indicate that soil was formed between c. 8.0 and 6.0 cal ka BP and that the pedological evidence fits the record of the North Atlantic Holocene IRD events (“Bond events”) and the so-called “Holocene climate optimum”. The geoarchaeological record reveals that Neolithic inhabitants settled upon a stable surface, still affected by soil formation that was suddenly interrupted by slope wasting, probably in correspondence to Bond event 4, at c. 6.0 cal ka BP.  相似文献   

16.
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.  相似文献   

17.
The Sabana de Bogotá in the northern Andes is an interesting region to investigate temporal patterns of dietary variation because it counts with a vast archeological and osteological record for the last 10,000 years. In this paper, stable isotope data of human archeological bone collagen and apatite were used to study the evolution of diet and major subsistence transformations taking place during the Holocene (~9000–600 cal BP). Paleoenvironmental reconstructions and the isotopic ecology of the Sabana de Bogotá were used as an interpretative baseline. Stable isotope measurements (δ13Ccol, δ13Cap, δ15N, and Δ13Ccol-ap) representing hunter-gatherers, horticulturalists, and agriculturalists (N = 134 individuals) were analyzed by using bivariate, regressional, and discriminant statistical techniques. Results show that early Holocene hunter-gatherers (9000–7000 cal BP) consumed mostly C3 vegetal resources locally available. In contrast, animal protein was less important. Middle Holocene hunter-gatherers (6000–4500 cal BP) continued with the food foraging pattern observed in the earlier counterparts and presented a slight increase in C3 animal protein intake. During the initial late Holocene ca. 4000 cal BP, important shifts in subsistence strategies occurred when populations presented a trend toward mixed C3/C4 diets, and by ca. 3500 cal BP, there is a clear signal of C4 crops (i.e., maize) consumption concomitant with the introduction of ceramic technology. During the final late Holocene (last 2000 cal years BP), intensive agriculture was adopted and humans presented relatively diverse diets integrated by C4 and C3 crops, C3-C4 feeding animals, and freshwater resources. Such dietary change coincides with an increase in sociopolitical complexity, population size, and a general decline in health.  相似文献   

18.
Recent sand quarrying operations for building and construction work in the eastern extremity of the Rub' al-Khali sand sea has revealed sediment exposures through a number of coastal and inland dunes. In the al-Daith district of Ras al-Khaimah (U.A.E.) a Holocene shell midden was exposed 2.8 m below the present dune surface interstratified between phases of Late Pleistocene and late Holocene dune sands. C14 and OSL ages constrain the site giving an insight into phases of landscape instability, dune formation, rates of sediment accretion, and a period of stability and human occupation. To date, Hafit period sites (5200–4500 cal BP) have been recorded in large numbers in the mountains and gravel plains of the Oman mountains. Coastal shell middens have not, as yet, been ascribed to the Hafit period from this part of the region and the study presents the first radiocarbon age from such a site. This study indicates the potential that many other sites exist elsewhere buried under late Holocene dune sediments and these provide an important insight into the development of the coastal landscape of this region.  相似文献   

19.
Prolonged stability of the southern tableland of NSW, developed on early Tertiary Monaro basalt, is evident from weak landscape dissection and numerous small lakes. However, poorly developed soils and weathered zones are inconsistent with prolonged Cainozoic weathering or formation under climates substantially different to the present. Thin Holocene sediments are also at variance with the sizes of the lake basins. Low depositional landforms, termed ‘lake shadows’, occur on the eastern perimeters of most lakes, and comprise clay pellets blown from basin floors during dry phases. Deflation, dominantly during Quaternary glacial periods, and reactivated today, is responsible for the thin soils and sediment cover. The lake basins are partly solutional and partly deflational features. The modern soil cover reflects the modern climate.  相似文献   

20.
This study aims to reconstruct the Holocene fluvial history of the Tremithos river, south central Cyprus and examine linkages to regional and local archaeological records. Three stratigraphic profiles (Sp1, Sp2 and Sp3) located in the lower valley have been investigated using sedimentology and magnetic parameters. The 14C dating of 10 samples reveals mid-Holocene ages for Sp1 and Sp2, while the upper most part of Sp3 can be attributed to the early to mid-Holocene. Two main phases of vertical accretion have been recognised: the first, recorded in the lower most part of Sp3, could not be dated but might relate to the late Glacial period. It is not associated with any archaeological artefacts. The second, recorded in all profiles, dating from ca. 5000 to ca. cal 2800 BC, spans the Late Neolithic Sotira (cal 4800/4000 BC) and Late Chalcolithic (cal 2900–2500 BC) cultures. The sediments of Sp1 and Sp2 are up to 8–10 m thick and mainly composed of fine material. However, an intercalated phase of coarse sediment has been identified at the beginning of the third millennium BC, indicating a sudden change in river dynamics, potentially associated with the 5.2 ka rapid climate change regional event. Typical mid-Chalcolithic (ca. cal 3300–3050 BC) ceramics found in a palaeosol in Sp2 indicate for the first time human occupation of the Tremithos river terraces. Two other palaeosols have also been recognised in Sp3 and radiocarbon dated to ca. cal 5600–4100 BC and ca. cal 2900–2600 BC, respectively. These results make it possible to propose a palaeogeographic reconstruction of the Holocene evolution in the Tremithos valley and to make a preliminary assessment of the relative roles of tectonics, climate and anthropogenic forcing.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号