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.
Ardèche, a department of Rhone Alpes region, is rich in prehistoric sites belonging to a very large chronological period dated back to 350?000 years ago. But, the prehistory of the region has been unknown for a long time, mainly, because of its distance from traditional centres of research. Jean Combier, in his abstract dated 1967, defined for the first time Upper Palaelolithic stages: only towards the acquisition of new data, we are now able to suggest a new evolution for the Magdalenian from its origins to the Alleröd climatic episod. To define Ardèche originality within the Magdalenian context, we have compared its lithic industries with those of the Adaouste Cave oriental sites, the Cornille rock shelter and of the Gazel cave in the Aude western part. Ardèche Magdalenian dwelling is peculiar compared to the South West of France. Badegoulian has been substituted by a Mediterranean Facies culture rich in bladelets, the Salpestrian. This facies limited in its geographic extention to Gard and Ardèche, evolves gradually in situ gaining Magdalenian elements (such as backed bladelets and dihedral burins) giving birth to the transitory lithic complex of Huguenots and Baume d’Oullins Cave. An established Magdalenian is certified in the Blanchisserie camp, within a cold climatic context dated back to circa 16?000 years ago. Although the lithic industry is dominated by dihedral burins and backed bladeletse it is also characterised by some archaic features (such as keel endscrapers, transverse burins and scalene bladelets). The upper Magadalenian with bone harpoons appears soon in our region, in the Colombier rock shelter, in a fairly temperate climatic context dated according to 14C back to circa 14?000 BP. We could identify six stages within the evolution of this Upper Magdalenian.which are attested in the Colombier, Ebbou and Deux Avens Caves and in the Colombier rock shelter that has been occupied during several periods. The Magdalenian gradually changed loosing his most typical elements, the bladelets and burins supremacy has been substituted by Azilian elements (such as short endscrapers and curved backed points). But even if the Azilian process happens very early (before 12?500 BP) the Magdalenian, in its fundamental features, never disappears completely and it has never been substituted by classic Azilian. After Alleröd appears a culture characterised by the recovery of Magdalenian features similar to the Epimagdalenian defined by D. Sacchi in Gazel. The described evolution can be compared, as regard to its upper stages, to that of several sites of Rhone region as well as of the North West of France, which allow to define a culturally homogeneous province having the Rhone corridor with Ardèche as its Southern border. At the end of Palaeolithic this province broke up and Ardèche opened to the South and the Mediterranean from where seems to come the retouched large blade facies and endscrapers attested by the Colombier rock shelter dating back to 12?150 BP.  相似文献   

2.
《L'Anthropologie》2016,120(5):537-567
El Cierro Cave (Ribadesella, Asturias, Spain), located near the mouth of the River Sella, has yielded one of the most important Upper Palaeolithic sequences in northern Spain. To date, three major occupation periods at the cave have been identified and dated. The first was at the beginning of the Holocene (ca. 8500 BP; ca. 9000 cal BP); the second at the end of the Upper Palaeolithic, in the Younger Dryas (YD) or Greenland Stadial 1 (GS1) (ca. 11.200 BP; 12.700 cal BP) and the third during Greenland Stadial 2 (GS2) (ca. 16.300–15.500 BP; ca. 19.200–18.700 cal BP). This paper describes the stratigraphy documented in the excavations performed by F. Jordá Cerdá and A. Gómez-Fuentes between 1977 and 1979 and presents the first radiocarbon determinations for the first two occupation periods, together with the study of the archaeological materials found in Level F. This level, dated to 15.500 BP (ca. 18.700 cal BP) is characterised by specialised red deer hunting and the gathering of marine resources (winkles). Various artefacts made from animal raw materials have been documented; both finished products and items in the process of being manufactured, as well as portable art objects. The lithic assemblage, consisting mainly of local raw materials with a small proportion of allochthonous flint, is characterised by an abundance of small bladelet cores and backed bladelets. These archaeological remains and the radiocarbon date mean Level F can be attributed to the so-called “Cantabrian Lower Magdalenian”. This period has been documented archaeologically and dated to a similar time at other sites in the River Sella valley and in the rest of northern Spain.  相似文献   

3.
In western Europe, the techno-economic changes that affected human societies during the 16th millennium BC suggest a deep reformulation of social relations that led to the emergence of Magdalenian features, thanks to a powerful cultural acceleration process. In central France, these mutations, contemporary with the Heinrich 1 climatic event, took place in a paleohistorical framework whose structure was less distended than in other regions: the cultural answers seem to disappear behind social “waves” (hypertrophy of the circulation of lithic raw materials, the sudden resurgence of blade debitage) expressed in this area since the early Upper Paleolithic. They allow us to discern, in the long term, how the original experiments of the Middle Magdalenian materialized. In the short term, some limited geological episodes, such as the recovery of the volcanic activity of the Massif Central around 16 ka cal BC, offer some possible stimuli of the rapid changes that affected technical systems. Their variations reveal the conditions, the aspects and the rhythms of the emergence of new ideological attributes that formed the traditional basis of Magdalenian societies.  相似文献   

4.
The importance of coastal resources in the late Upper Paleolithic of western Europe has been reevaluated in recent years thanks to a growing body of new archeological evidence, including the identification of more than 50 implements made of whale bone in the Magdalenian level of the Isturitz cave (western Pyrenees). In the present study, the assemblages of osseous industry from 23 Magdalenian sites and site clusters in the northern Pyrenees were investigated, systematically searching for whale-bone implements. The objective of this research was to determine if, and how, tools and weapons of coastal origin were circulated beyond Isturitz into the inland, and if similar implements existed on the eastern, Mediterranean side of the Pyrenees. A total of 109 whale-bone artifacts, mostly projectile heads of large dimensions, were identified in 11 sites. Their geographic distribution shows that whale bone in the Pyrenean Magdalenian is exclusively of Atlantic origin, and that objects made of this material were transported along the Pyrenees up to the central part of the range at travel distances of at least 350 km from the seashore. This phenomenon seems to have taken place during the second half of the Middle Magdalenian and the first half of the Late Magdalenian, ca. 17,500–15,000 cal BP (calibrated years before present). The existence of a durable, extended coastal-inland interaction network including the circulation of regular tools is thus demonstrated. Additionally, differences between the whale-bone projectile heads of the Middle Magdalenian and those of the Late Magdalenian document an evolutionary process in the design of hunting weapons.  相似文献   

5.
《L'Anthropologie》2016,120(5):588-609
The study of graphic convergences and divergences in Palaeolithic art is used to understand the culture, territories and interaction systems of human groups. La Covaciella cave has fifteen animal representations and other linear, dots and geometric motifs. The bison stands out; some were executed with complex technical procedures. Two of them were dated by C14 AMS, obtaining a result of 14,260 ± 130 BP (17,733–16,973 cal BP) and 14,060 ± 140 BP (17,503–16,260 cal BP). These correspond chronologically with the beginning of the middle Magdalenian or the very end of the lower Magdalenian. Similar depictions to the bison at La Covaciella are located in other areas of Western Europe. The repertoire of parietal bison displaying graphic similarities with those at La Covaciella is very large; both of the Pyrenean model (Niaux morphotype) and of the Perigordian model (Font-de-Gaume morphotype). A first consideration derived from the search for comparisons involves a new interpretation of the territorial value implied by the term Pyrenean style (Asturias, Cantabria, Basque Country, Navarre, Pyrénées-Atlantiques, Hautes-Pyrénées, Haute-Garonne, Ariège, Dordogne, Lot, Ardèche and Vienne). The Font-de-Gaume parietal morphotype is most common in Dordogne. In addition, in some cases, spatial complementariness has been found, with both graphic morphotypes. This article proposes different chronological and anthropological hypothesis to explain the distribution and coexistence of the two graphic models.  相似文献   

6.
Recent definition of the Cantabrian Lower Azilian has turned the Late Upper Magdalenian/Azilian transition into one of the most interesting archaeological ages in the area. This period is considered representing the earliest Azilian groups in Asturias. Critic review of Cueva Oscura de Ania record, in the center of Asturias, has allowed us to give full details of the Lower Azilian archaeological characteristics. Cueva Oscura de Ania archaeological collection shows archaic traits, close to those from Cueva de Los Azules and Cueva de La Riera, two eastern asturian sites. These likenesses suggest a high stylistic and technical uniformity in distant areas during a critical period, when Palaeolithic groups changed their subsistence strategies. Cueva Oscura de Ania archaeological and polinic records suggest that this deposit was built at the beginning of the paleoclimatic phase known as Alleröd/Cantabrian VIII (12 000-10?800 BP), when numerous cantabrian sites suffered high erosion processes. All these circumstances convert Cueva Oscura de Ania in a fundamental site to get a best knowledge of the origin and development of the Cantabrian Azilian. The study of its bone collection allows us outline new hypothesis about this archaeological period.  相似文献   

7.
《Comptes Rendus Palevol》2019,18(6):663-684
The stratigraphical complex preserved at the site of Menez–Dregan I (Brittany, France) displays an alternating sequence of 17 occupation levels and of 4 marine deposits, between ca. 450 and 150,000 years (stratigraphical units 9a and 3b). The lithic industry retrieved at the site is extremely abundant, with more than 153,000 artefacts over 3 cm in length, as well as millions of knapping debris, and corresponds to a regional facies of the Acheulean, with heavy-duty tools essentially represented by choppers, as well as a few handaxes and cleavers. This paper presents a first synthesis of the data produced for almost 30 years on the site of Menez–Dregan I. The typological study of the entire lithic collection is now complete and allows us to assess the different human occupations that occurred at this site during the Lower Palaeolithic.  相似文献   

8.
The Magdalenian techno-complex evolved in Western Europe and Central Europe between 17-12 kyr BP, concentrated in Spain on the Cantabrian Coast and in France in Pyrenees and Dordogne, in Central Europe in Poland and Moravia. In our study we analyse portable art on hard animal tissues from Moravian sites (Pekárna, K?í?ova, Rytí?ská), Czech Republic. Comparative material was provided by sites in South-western France (Laugerie, Basse, Enlène). The results of the technological, stylistic and typological comparisons confirm our hypothesis that the Magdalenian portable art from sites in Moravia belong to the Magdalenian techno-complex. The comparison of typological objects in Moravia, like decorated bone disc, pendants, Venus, bâton percé, spatule, shows that their variability is well in the range expected for techno-complex. The same technological pattern can be found between typological objects of spatule as a technology of decoupage but which is applied on different anatomical parts of animal raw material. We discussed the question about local origin of the objects. Technological comparison shows that engraving and bas-relief are more frequent in Moravia than in South-western France sites. This can be explained as a regional based preference of technology for expression of different subjects of mobile art, but also as a possible bias due to small sample size and differences in sampling of our studied objects. Engraving present similar technological characteristics that are featured in both areas. Design, like organization of space and size of the engraving, can be interpreted as an existence of contact between both groups and presence of one Magdalenian techno-complex.  相似文献   

9.
Parco cave, discovered in 1974, has yielded more than 50 objects fashioned of hard animal parts from levels dating to later phases of the Magdalenian. In the work described here, we have undertaken a technotypological analysis of this previously unstudied bone and antler assemblage. The osseous series from Parco are homogeneous and very similar to those from nearby sites of roughly the same time period; that is to say of the late Upper Magdalenian of the peninsular Mediterranean. The latter are composed primarily of hunting weapons dominated by antler projectile points, as well as eyed bone needles and a few shell ornaments. Technological analysis shows production in which there is a tight relationship between morphological type and raw material employed. The production schema saw the removal of blanks by means of groove and splinter technique, followed by shaping of pieces by scraping and finishing of them - in some cases by abrasion.  相似文献   

10.
A 9.14 m long sediment sequence was recovered from Lake Fryxell, Taylor Valley, southern Victoria Land, Antarctica, and investigated for its chronology and sedimentological, mineralogical, and biogeochemical changes. The basal part of the sequence is dominated by coarse clastic matter, i.e., mainly sand. The sediment composition suggests that a lake existed in Fryxell basin during the Middle Weichselian by ca. 48,000 cal. year BP. After a short period of lake-level lowstand ca. 43,000 cal. year BP, lower Taylor Valley became occupied by the proglacial Lake Washburn, which was at least partly supplied by meltwater and sediments from the Ross Ice Sheet that was advanced to the mouth of Taylor Valley. Evaporation of Lake Washburn to lower levels started during the Last Glacial Maximum at ca. 22,000 cal. year BP, long before the Ross Ice Sheet retreated significantly. Lake-level lowering was discontinuous with a series of high and low stands. From ca. 4000 cal. year BP environmental conditions were similar to those of today and lower Fryxell basin was occupied by a small lake. This lake evaporated to a saline or hypersaline pond between ca. 2500 and 1000 cal. year BP and refilled subsequently.  相似文献   

11.
Abstract. Analysis of pollen, charcoal and loss-on-ignition in peat cores from a Picea aèies-dominated swamp forest in central Sweden show the vegetation changes and disturbance patterns over 9500 yr. Six major sequences of local vegetation development are identified: (A) Pinus period, ca. 9500–7000 cal. BP; (B) Open mire period (ca. 7000–4500 cal. BP; (C) Betula period, ca. 4500–2300 cal. BP; (D) Picea period (ca. 2300–1000 cal. BP; (E) Human impact period (ca. 1000–100 cal. BP); and (F) Period of human abandonment during the last ca. 100 yr. The swamp forest has been highly dynamic in response to various natural and anthropogenic disturbance agencies. Several fires have heavily influenced the vegetation development. During the last ca. 900 yr human influence has been important, initially from grazing and trampling by domesticated animals (ca. 1000–500 cal. BP), and subsequently small-scale cereal growing (ca. 400–100 BP). Cutting, burning and animal browsing influenced the structure and dynamics of the swamp forest by creating a more open stand and suppressing tree regeneration. Recent cessation of human impact has led to increased tree regeneration and a denser swamp forest stand. The present high biodiversity, and subsequent conservation interest does not result from long-term stability or absence of fire and human impact. However, in spite of repeated disturbances, a continuity of old and senescent trees produced a forest type with abundant dead wood. With the relatively minor importance of fire over long periods of time, the swamp forest developed a structure maintaining a high biological diversity. An important issue for maintaining long-term biodiversity in the boreal landscape must be to create a mosaic where different forest types are present, with a variety of structures, substrates and processes, to provide a certain degree of freedom for species to move around in the landscape.  相似文献   

12.
《L'Anthropologie》2014,118(3):328-346
Rond-du-Barry cave is situated in the centre of the Cenozoïc sedimentary basin of Puy-en-Velay in a mountainous environment. It contains Middle Palaeolithic, Badegoulian, Magdalenian and more recent occupation levels. Lying between two major river corridors (the Loire to the west and the Allier to the east), this site provides a special opportunity for defining exploitation and management modalities linked to the territory occupied by the prehistoric humans who inhabited the cave and the role played by the landscape's structural elements in human behavior at the end of the Upper Pleistocene. Lithic raw material analysis of the archaeological assemblages allowed us to define the dispersal of raw materials used in the site. Such dispersal has for some time been considered to provide a reliable reflection of actual movements of human groups. Our study, based on a modified methodology incorporating the concept of a chaine évolutive for flint, focused on the lithic artifacts from Rond-du-Barry unit F2, which are attributed to the Badegoulian. The results of our study differ from those of previous studies in terms of the diversity of the raw material being used and the frequency of occurrence for each type. Our conclusion is that Badegoulian humans were not physically constrained by a familiar territory, but traveled and/or traded widely in their quest for suitable raw materials. The diversity in the lithic raw materials, gathered locally and semi-locally from different primary and secondary outcrops demonstrates this territorial range. Importation of siliceous raw material originating from the meridional edge of the Paris basin (Berry, Touraine) suggests a planned resource-use strategy for obtaining large pieces of flint, which are rare in the regional outcrops. However, unraveling the resource use strategies to this degree of intention lies beyond what can be revealed by the lithic material alone.  相似文献   

13.
《Comptes Rendus Palevol》2014,13(7):623-636
A series of 36 radiocarbon AMS ages produced from separate bone fragments has prompted a new appraisal of the archaeological sequence of the Rond-du-Barry Cave (Polignac, Haute-Loire). A huge rock-fall of unknown age underlies Unit H, which contains evidence of the oldest human occupation of the site consisting of a Middle Palaeolithic assemblage dated to between 40 and 33 kyr. The first Upper Palaeolithic occupation of the Cave occurred later. In Unit F, three Badegoulian occupation sectors can be identified that are dated to between 20 and 17.5 kyr. The uppermost units, E and D yielded Middle and Upper Magdalenian dates of between 15.4 and 12.4 kyr. Within Unit E, a tephra related layer (E6) is likely to belong to a distal southern lobe of an eruptive event that was centred in the Chaîne des Puys, 100 km to the north. Unit D shows evidence of being re-worked at least during Mesolithic/Neolithic times, circa 6.5/4.9 kyr. The sum of this new evidence demonstrates the existence of a previously unrecognised stratigraphic and spatial complexity within the Rond-du-Barry archaeological deposits, which demands that new investigations be made in this cave.  相似文献   

14.
Situated a few kilometres from Angles-sur-Anglin (Vienne, France), the Roc-aux-Sorciers cave has yielded in 1927 and 1950 industry of the Middle and Upper Magdalenian periods. Our analyses of the sedimentary filling, dated from isotope stage 2, demonstrate the existence of two climatic sequences in the six ensembles defined during the excavations. A first sequence, at the base of the cave filling, corresponds to the occupation levels of the Middle Magdalenian and of the early Upper Magdalenian. At that time, the climate was globally cold and particularly humid, a conclusion that does not support Bastin's 1975 hypothesis on the oscillation of Angles-sur-Anglin, which postulates a mild and humid climate. In fact, the climate evolved progressively towards a slight warming from the base to the top of the stratigraphy. During the second sequence, corresponding to the occupation period of the Upper Magdalenian, the relatively stable climate was slightly warmer and quite humid. Stratigraphical and sedimentological data thus provide new information on the conditions under which the filling was deposited and on the palaeoclimatology of the Poitou-Charentes region during Magdalenian occupation.  相似文献   

15.
Lithic refitting studies have consistently contributed to address two specific research aims: the intra-site mobility and identification of preferential areas or latent structures, and the in-depth analysis of the knapping technologies and core reduction strategies. Multiple refits, in particular, can produce highly detailed data on knapped stone technology. Elucidating human skills and lithic economy, a potential still rarely evaluated for Discoid technology: a stone knapping method largely spread across the Middle Paleolithic of Europe. The opportunity to explore Neanderthal knapping behavior is provided from the remarkable discovery of a primary lithic waste concentration in the Mousterian Discoid level of the Grotta di Fumane, Italy, dated to at least 47.6 ky cal BP. With a combined approach that included the 3D virtual interaction, we were able to reproduce a complete reduction sequence that supports the technological analysis conducted on the lithic assemblage. Results lead to a better comprehension of the knapper's technological and technical behavior, including the detection and quantification of economic objectives and productivity.  相似文献   

16.
We reconstructed the Holocene developmental history of a kettle-hole peatland in the Tuchola Forest of Northern Poland, using pollen, testat amoebae and plant macrofossil indicators. Our aims were to determine the timing and pattern of autogenic succession and natural and anthropogenic influences on the peatland. Northern Poland is under mixed oceanic and continental climatic influences but has so far been less studied in a palaeoecological context than more oceanic regions of Europe. In the first terrestrial developmental phase of the mire, the testate amoebae-inferred depth to water table revealed two major dry shifts at ca. 9400 (end of lake phase) and ca. 7100 cal BP (a period of global cooling and dry shift in Western Europe). Conditions became wetter again in two steps at ca. 6700 and ca. 5800 BP after a dry event at ca. 6100 BP. The timing of the wet shift at 5800 BP corresponds to wet periods in Western Europe. Peat accumulation rates were low (0.1 mm yr− 1) between ca. 5600 and ca. 3000 BP when sedges dominated the peatland. In the last 2500 yrs surface moisture fluctuated with wet events at ca. 2750–2400, and 2000 BP, and dry events at ca. 2250–2100 and 1450 BP. After 1450 BP a trend towards wetter conditions culminated at ca. 500 cal BP, possibly caused by local deforestation. Over the mire history, pH (inferred from testate amoebae) was mostly low (around 5) with two short-lived shifts to alkaline conditions (7.5) at ca. 6100 and 1450 BP indicating a minerotrophic influence from surface run-off into the mire. Up to about 1000 BP the ecological shifts inferred from the three proxies agree with palaeoclimatic records from Poland and Western Europe. After this date, however correlation is less clear suggesting an increasing local anthropogenic impact on the mire. This study confirms that kettle-hole peatlands can yield useful palaeoenvironmental data as well as recording land-use change and calls for more comparable studies in regions are the interface between major climate influences.  相似文献   

17.

Questions

As the dominant tree in many European forests, Fagus sylvatica functions as an ecosystem engineer, yet its istory remains little understood. Here we ask: (a) are there indications for its presence in southeast France during the last Glacial period; (b) what was the timing of the expansion and decline of F. sylvatica dominated forests; (c) which factors influenced their dynamics and in particular to what extent did past precipitation changes impact upon them; and (d) at which altitudes did these beech forests occur within the region?

Location

Languedoc, the French Mediterranean area.

Method

This article presents a well dated and high‐resolution pollen sequence covering the last 7,800 years from the Palavas Lagoon in the Languedoc together with a review of Fagus charcoal occurrences in the Languedoc and the lower Rhône Valley, and a review of pollen data from a compilation of 69 sites in southeast France.

Results

The Palavas pollen sequence provides a regional summary of F. sylvatica abundance changes near the Mediterranean coast. Around 6,000 years cal BP , an abrupt transition from small beech populations to well‐developed forests is recorded. The maximum development of beech forests occurred between 4,000 and 3,000 years cal BP , while F. sylvatica started to regress after 3,000 years cal BP .

Conclusion

Scattered F. sylvatica populations probably survived throughout southern France during the last Glacial period. F. sylvatica started to spread around 8,000 years cal BP while beech forests never expanded before 6,000 years cal BP . The complex patterns of F. sylvatica expansion in southern France after 6,000 years cal BP suggests that a combination of global (climate change) and local (human impact) factors were responsible for this major change. Recurrent abrupt climate changes, the aridity trend and human deforestation caused beech forests to decline after 3,000 years cal BP .
  相似文献   

18.
Sediments from Xinyun Lake in central Yunnan, southwest China, provide a record of environmental history since the Holocene. With the application of multi-proxy indicators (total organic carbon (TOC), total nitrogen (TN), δ13C and δ15N isotopes, C/N ratio, grain size, magnetic susceptibility (MS) and CaCO3 content), as well as accelerator mass spectrometry (AMS) 14C datings, four major climatic stages during the Holocene have been identified in Xingyun′s catchment. A marked increase in lacustrine palaeoproductivity occurred from 11.06 to 9.98 cal. ka BP, which likely resulted from an enhanced Asian southwest monsoon and warm-humid climate. Between 9.98 and 5.93 cal. ka BP, a gradually increased lake level might have reached the optimum water depth, causing a marked decline in coverage by aquatic plants and lake productivity of the lake. This was caused by strong Asian southwest monsoon, and coincided with the global Holocene Optimum. During the period of 5.60–1.35 cal. ka BP, it resulted in a warm and dry climate at this stage, which is comparable to the aridification of India during the mid- and late Holocene. The intensifying human activity and land-use in the lake catchment since the early Tang Dynasty (∼1.35 cal. ka BP) were associated with the ancient Dian culture within Xingyun’s catchment. The extensive deforestation and development of agriculture in the lake catchment caused heavy soil loss. Our study clearly shows that long-term human activities and land-use change have strongly impacted the evolution of the lake environment and therefore modulated the sediment records of the regional climate in central Yunnan for more than one thousand years.  相似文献   

19.
Detailed botanical (microfossil and macroremain), zoological and geochemical analyses (major and trace elements including C, Al, S, Ca, Fe, P, As, Zn, U, Ba and Rare Earth Elements) of organic deposits provide new insights into Early Holocene environmental change in the Kreekrak area (southwestern Netherlands). The age assessment of the record is based on high resolution AMS 14C wiggle-match dating (WMD). For the first time an AMS 14C WMD based chronology covering the Late Glacial/Holocene transition and early Preboreal is introduced for a site in The Netherlands.The Kreekrak botanical record reflects the end of the Younger Dryas to early Boreal and can be well correlated with pollen records from other sites in The Netherlands and Belgium. The palaeo-topography showed that the Kreekrak deposits formed in an abandoned channel of the River Schelde. Around ca. 11,490 cal BP, at the end of the Late Glacial/Holocene transition, infilling of the lake started with predominantly organic deposits in slowly running water. As a result of the warmer climate the area became forested with birch and poplar during the Friesland Phase (ca. 11,490-11,365 cal BP). Biological productivity of the lake and its surroundings increased. Aquatic vegetation developed in the lake, while shrubs of willow, reed swamps and grasslands fringed the shores. Precipitation increased, which caused a rise in the lake water table and an increase in the supply of oxic surface (= river) water into the Kreekrak lake. During this period, the Kreekrak lake was fed by inflowing river water, run-off, precipitation and seepage of Fe-rich groundwater. Around ca. 11,435 cal BP the water became stagnant probably as result of a total cut-off of the river channel. Inflow of river water ceased, while the supply of reduced Fe-rich groundwater became dominant. During the Rammelbeek Phase (ca. 11,365-11,250 cal BP), the climate was more continental and the abundance of grasslands and open herbaceous vegetation increased. Biological productivity remained high. In the lake, the supply of Fe-rich groundwater continued, the water level slightly decreased but aquatic vegetation remained present. At the end of the Rammelbeek Phase a sudden reduction in the supply of Fe-rich reduced groundwater caused a lowering of the groundwater level in the area, resulting in the development of a hiatus. Due to this hiatus, the Late Preboreal (11,250-10,710 cal BP) is absent from the record. During the early Boreal (10,710-10,000 cal BP) the landscape became densely forested and accumulation of peat in the former lake resumed due to a slowly rising groundwater level. The Boreal was a relatively stable period with low sedimentation rates.The combination of palaeobotanical and geochemical analyses in the Kreekrak record shows a close interrelation between landscape development and geochemistry. It appears that the environmental development of this area during the Late Glacial/Holocene transition and Early Holocene was largely influenced (directly or indirectly) by major climatic changes that occurred during this period, which determined local phenomena such as the composition and density of the vegetation, occurrence of seepage and river activity. Further research of this type has the potential to develop the application of major- and trace element geochemistry in palaeoenvironmental reconstructions.  相似文献   

20.
This paper explores the cultural sequence for the period 12,500–9000 BP in the Mediterranean coast of the Iberian Peninsula. According to the traditional division by Fortea, this period starts with the end of the Upper Magdalenian, followed by two facies: the Microlaminar Epipalaeolithic and the Geometric Epipalaeolithic (Filador type), (related to Sauveterrian facies). The data collected in recent years suggest a change or amendment to this previous proposal, which now would be divided into four phases: Final Upper Magdalenian, Early Epimagdalenian, Recent Epimagdalenian and Microlaminar Sauveterroid. This paper discusses each of these periods examining the evolution of the stone tools and concluding that in the Mediterranean coast of the Iberian Peninsula the Magdalenian tradition continues with little changes until the advent of the Mesolithic.  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