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.
This text is a synthesis of the results from the archaeological study of Ndindan site (Ndedama in Ewondo language) (3°54’N; 11°30’E), located north-west of Yaoundé urban area, on the Mont-Febe eastern side. An overview of the historical of prehistoric research in Yaoundé is given. It then tackles the study of the archaeological materials and supplies the radiocarbon datings of the site. A reconstitution of ancient population and of the paleoeconomy on the regional scale is at last made.  相似文献   

2.
Pitfalls are formations characterized by a vertical opening that connects the karstic system to the outside. The presence of faunas trapped without the intervention of man or carnivores, offers the opportunity to establish a fossil referential of modifications generated by identified taphonomic agents. Three natural deposits containing large faunal accumulations feed this work. Their characteristics differ. The Igue des Rameaux, to Saint-Antonin-Noble-Val in Tarn-et-Garonne, is a pitfall which contains two accumulations of fauna independent from the Middle Pleistocene. Scavenging by man and carnivores (hyenas and wolves) are observed. The Igue du Gral, to Sauliac-sur-Célé in Lot, is a second pitfall. His principal phase of filling took place 14,000 years ago. Man did not exploit this assemblage. The activity of wolves is locally important, some animals are scavenged. The Grotte de l’Escale, in Bouches-du-Rhône, contains a very important filling of lower and middle Pleistocene. For the levels presented here, only a very weak presence of carnivores is attested. The thar (Hemitragus bonali) is the majority specie. We describe here the main forms of climato-edaphic modifications: fragmentation, dissolution, weathering and deposits observed on the osseous material. A differential analysis enables us to evaluate the variability of the situations according to the stratigraphic units and the different species. In a second time, we estimate the impact of the taphonomic agents on the differential conservation of bones and skeletal representations. Many phenomena are producing a significant correlation between anatomical representations and osseous densities. However, we find for all the species a certain homogeneity in the skeletal profiles where no precise element dominates. In a last part, we give two examples of the use of the taphonomic phenomena in the individualization of filling episodes within sometimes disrupted stratigraphies.  相似文献   

3.
4.
Résumé Des papillons de carpocapse Cydia pomonella L., mâles et femelles séparés, sont soumis au contact des résidus secs du CGA 184'699, un inhibiteur de croissance d'insectes (ICI) et du fenoxycarb, un régulateur de croissance d'insectes (RCI). Ils sont ensuite regroupés dans boîtes non traitées pour l'accouplement et la ponte. La fécondité du carpocapse n'est pratiquement pas affectée par ce conditionnement mais sa fertilité diminue avec l'augmentation de la concentration des produits et avec la durée d'exposition. Avec le CGA 184'699, l'efficacité ovicide induite atteint environ 50% suite à un contact de trois jours avec les résidus d'un traitement à 100 mg/l, alors qu'avec le fenoxycarb elle s'élève à 87% dans les mêmes conditions. Avec le CGA 184'699, seul le contact des femelles avec les résidus provoque cette réduction de fertilité, alors que le fenoxycarb agit sur les deux sexes.
Summary Codling moth, Cydia pomonella L., males and females were exposed separately to contact with dry residues of CGA 184'699 an insect growth inhibitor (IGI) and fenoxycarb, an insect growth regulator (IGR), The sexes were then grouped together in non treated boxes for mating and egglaying. Fecundity of codling moth was little affected by this treatment but its fertility decreased with increases in the concentration of products and the duration of contact. Induced ovicidal efficacy was about 50% after three days contact with the residues of a 100 mg (a.i.)/l application of CGA 184'699, whereas the same conditions led to about 87% efficacy with fenoxycarb. With CGA 184'699, only contact by females affected egg eclosion whereas fenoxycarb acted on both sexes.
  相似文献   

5.
This article summarizes the results of archaeological research led from 1995 to 1998 in the fauna reserve of Lopé (Gabon). The excavated sites were dated from the Upper Pleistocene to the Post-colonial period. It is the longest and the most complete archaeological sequence presently known in Central Africa. These results show evidence of human presence in the reserve for over 40?000 years and that this greatly contributed to the preservation of the ecotone landscape of Lopé. In addition, these results offer the first systematic analysis of the sites and the ceramic artefacts produced and used in the centre of Gabon during the last three millennia. Supported by chronological, linguistic and palaeoenvironmental data, these results allow us to refine the ceramic typology and to prove the antiquity of husbandry, agricultural practices and iron production in this part of Africa. Finally, they allow us to clarify the various phases of settlement in the reserve and to reveal an important historic phenomena in connection with the expansion of the bantu languages and/or the bantu speaking peoples, who populate a third of the African continent.  相似文献   

6.
A paleolimnological study can be particularly accurate in situations where the species found in the sediments have persisted in the same lake and can provide a direct modern analogue for interpretation. Lake Tigalmamine, thus, represents an exceptionally favourable context, compared to most paleolakes in North Africa, as this site allows comparing the fossil remains of the Characeae to those produced by the living plants. Tigalmamine is a hydrosystem composed of three karstic lakes located at 1626 m above sea level in the Middle Atlas of Morocco. The site had been the subject of a 16 m long core taken in the center of the central lake under 16 m of water (core C 86 in Lamb and Kaars, 1995 [The Holocene 5 (1995) 400-408]). The section represents the total of the Holocene from 10,200 BP to Present (El Hamouti et al., 1991 [Comptes Rendus de l’Académie des Sciences de Paris 2 (1991) 259-265]; Lamb et al., 1995 [Nature 373 (1995) 134-137]). The latter published a synthesis of the pluridisciplinary studies conducted on this core. Also, the numerous gyrogonites isolated from that core had been determined as Chara hispida (Soulié-Märsche in Benkaddour, 1993 [Changements hydrologiques et climatiques dans le Moyen-Atlas marocain : chronologie, minéralogie, géochimie isotopique et élémentaire des sédiments lacustres de Tigalmamine. PhD thesis, Université Paris-Sud, Orsay (inédit)]). Further fieldwork at Tigalmamine by the authors of the present paper in year 2000 showed that Chara hispida is still present in the lake where it forms a belt of submerged vegetation restricted to the range of 2 to 9 m water depth. This paper describes the morphological and ecological characteristics of the extant Chara hispida as a reference for the interpretation of the fossil remains. Based on these data, the frequency changes of the gyrogonites in the core sediments become significant in terms of bathymetry. The detailed analysis of the charophytes from the core, as a complement to the previous studies, confirms the existence of four Holocene phases with lake level low stand at Tigalmamine. The aim of the present study is to enhance the value of the charophytes as a useful complementary tool for paleolimnological reconstruction.  相似文献   

7.
In 2001 and 2003, several occipital fragments of a single mature skull were unearthed on the site of les Pradelles (Marillac-le-Franc, Charente). The archaeological context of the deposit allowed us to provisionally assign the remains to the Neandertal taxon. A morphometric study of this piece was conducted in order to confirm its placement in this lineage. Some features observed on this specimen and commonly described among Neandertals (e.g. the presence of a suprainiac fossa) as well as dimensional data locate the les Pradelles occipital within the morphological variability of Neandertals.  相似文献   

8.
9.
Palynological studies realized from a borehole drilled on the site of ANDRA (Agence Nationale pour la gestion des Déchets RAdioactifs; Aube Centre near Soulaines, Paris Basin, France) show a sedimentary discontinuity between, on one hand, the Argiles à Plicatules (lower Aptian in age) and Argiles Ostréennes (Lower Barremian/Upper Barremian in age) and, on the other hand, between these same Argiles Ostréennes and the Calcaire à Spatangues (Lower Hauterivian). These conclusions argue against the chronostratigraphical subdivision recently proposed on the basis of sequence stratigraphical and sedimentological interpretations.  相似文献   

10.
Résumé La présente étude porte sur deux séries de données récoltées en baie de Biétri (lagune Ebrié, Côte d'Ivoire). La première concerne un programme d'échantillonnage à basse fréquence (octobre 1985–mars 1986), au cours duquel ont été mises en évidence les conditions hydroclimatiques nécessaires à la suppression dans ce milieu du gradient de densité (augmentation de la salinité de surface, refroidissement des eaux lagunaires consécutif à une remontée côtière). La seconde se rapporte à un échantillonnage à haute fréquence (janvier–février 1987), sur le même site, afin de définir les mécanismes et les conséquences écologiques de la déstratification. Lorsque les conditions hydroclimatiques sont réunies, la déstratification proprement dite se réalise à l'occasion d'une séquence de vive-eau, lors d'une basse basse-mer exceptionnelle, par l'accélération des déplacements d'eau de surface dans la baie, traduite par un nombre de Richardson minimal. Cette déstratification permet une homogénéisation des profils verticaux des concentrations en sels nutritifs, mais surtout, elle entraîne une disparition de 90% de la charge en N-NH4 et de 60% de celle en P-PO4. Une modification de l'environnement chimique des eaux de l'hypolimnion lors de la réoxygénation est suggérée pour expliquer cette brutale et transitoire disparition. A l'opposé, la répartition verticale des biomasses semble peu affectée par la suppression du gradient de densité, la topographie des fonds interdisant l'établissement d'importants mouvements convectifs. Ainsi, les conséquences biologiques de la déstratification dans ce milieu estuarien eutrophe sont peu marquées, et sans comparaison avec les modifications hydrodynamiques et hydrochimiques observées à cette occasion.
Two sets of data were collected in the Biétri bay (Ebrié lagoon, Côte d'Ivoire). The first one concerns a program with a low frequency sampling (October 1985–March 1986), during which hydroclimatic conditions necessary to the suppression of the density gradient (increasing surface salinity, cooling of surface waters in relation with a coastal upwelling) were defined. The second one refers to a high frequency program (January–February 1987), in the same area, in order to describe the mechanisms and the ecological consequences of the destratification. When hydroclimatic conditions are favorable, destratification occurs during a spring tide period, corresponding to an exceptional low low waters, induced by a higher tidal current velocity in the bay, evidenced by a low Richardson number. That destratification allows an homogenization of vertical profiles of nutrient concentrations, but leads mainly to the disappearance of 90% of N-NH4 and 60% of the P-PO4 loads. A modification of the chemical environment in the hypolimnion during its re-oxygenation is proposed to explain this sudden and transitory disappearance. On the contrary, the vertical distribution of biomass seems to be little affected by the gradient suppression, the bottom topography preventing from important convective movements. Thus, the biological consequences of the destratification in this eutrophic estuarine area are not as important as the hydrodynamical and hydrochemical modifications observed during this phenomenon.
  相似文献   

11.
Buran-Kaya III site, in Crimea, provides an exceptional stratigraphic sequence, extending from Middle Paleolithic to Neolithic. Among the archaeological layers allocated to the Gravettian (sensu lato), more than 170 anthropological remains have been discovered in the layer 6-1. They represent the oldest Upper Paleolithic modern humans from Eastern Europe in a well-documented archaeological context. The aim of this article, based on dental remains and enamel dental hypoplasias in particular, is to evaluate the health of the modern humans, which lived more than 32,000 years BP ago in Crimea. This study puts into the light the low frequency of hypoplasias (occurring in the two youngest individuals). This article complete the rare studies concerning the presence of this physiological stress during the Early Upper Paleolithic and confirm the scarcity of enamel dental hypoplasias and dental pathologies, such as caries, at this period.  相似文献   

12.
The thick Quaternary deposits of the Caune de l’Arago (Pyrénées-Orientales, France) are dated to between 690 000 and 90 000 years old. At least fifteen different archeostratigraphical units have been identified within these deposits, each corresponding to distinct prehistoric occupations. Numerous stone tools made from several different rock types, have been discovered in each unit. The tools present specific characteristics concerning the choice of raw materials, the typology, and the technology used to produce them. Morpho-technological study of the different components of the assemblage contributes to a better understanding of the debitage methods used for their production. Each raw material is considered individually in order to ascertain its origin in the environment, its typological role and the technology applied during its exploitation. Defining production systems leads to the characterisation of the assemblages from each unit. When compared, they reveal common elements, as well as differences, suggesting evolutionary trends. Some observations are also made concerning the extent to which changing uses of the site may have influenced the general morphology of each assemblage, therefore taking into account exterior factors. Analysis of this rich stone tool assemblage helps to situate the Caune de l’Arago industry within the larger evolutionary context of the Lower Paleolithic in Mediterranean Europe.  相似文献   

13.
In March 1863, Jacques Boucher de Perthes found in the alluvia of Moulin Quignon (Abbeville, France) a human jaw in association with lithic artifacts and fossil bones of mammals. Quickly challenged, this discovery will appear as a fraud whose prehistorian was the victim. Since that time, the collection and the Moulin Quignon site are synonymous with an archaeological forgery. Forgotten for almost 150 years, these collections became in 2012 a research topic in the context of a program devoted to oldest settlements and Acheulean. The objective was to identify and study the whole 1863–1864 documentation set (human remains, artifacts, sediments, fauna bones, malacological remains, archives, papers, site) to allow further analysis of the whole subject.  相似文献   

14.
The archaeological localities of Barranco León and Fuente Nueva 3 in Orce, Grenade, in actuality have the oldest lithic artifacts in Europe; they are the oldest evidence of human occupation in the east of Europe. When compared the results from faunal analysis and magnetostratigraphical study, notably through the presence of Allophaiomys lavocati allow for a date of around 1.3 Ma. The raw material used for developing these lithic industries are, basically limestone or siliceous rocks, these raw materials selected were smoothed down in situ. The techniques used are knapping at raised with a hammerstone, and we can find all the different elements of the “chaine opératoire”. Both localities are characterised by the predominance of flakes and debris, cores, and some knapped cobbles sowing mediocre aspect. The technical and typological features of both lithic assemblages have an opportunist character but they are relatively sophisticated too.  相似文献   

15.
Pour rechercher son partenaire sexuel Zabrotes subfasciatus doit utiliser les signaux olfactifs émis soit par les mâles ou par les femelles. Le pouvoir attractif de l'odeur des mâles et des femelles sont donc étudiés et comparés par olfactométrie. Le comportement de mâles et de femelles vierges et inséminées, mis en contact des graines de la plante hôte ou non, est observé en fonction de l'âge des imagos. En aucun cas, les odeurs des mâles n'exercent une attraction sur les femelles. Les femelles vierges en absence de graines de haricot (Phaseolus vulgaris) n'exercent pas d'attraction sur les mâles vierges. Par contre les odeurs des femelles vierges mises en contact avec les graines de haricot sont très attractives pour les mâles vierges et varie en fonction de l'âge: il est plus affirmé chez les femelles plus âgées. L'émission de la phéromone sexuelle est interrompue après l'insémination des femelles mais reprend au bout d'un certain temps après celle-ci.  相似文献   

16.
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   

17.
The human remains recovered from “Grotte supérieure de Zhoukoudian” are the best-preserved Late Pleistocene human fossils in East Asia. For decades, as the representative of the Late Pleistocene human in East Asia, the Upper Cave skulls have been playing important role in the research of origins of modern Mongoloids and American Indians. With the advance of the origin and evolution of modern humans, more attention has been paid to the details and the mechanisms for the late Pleistocene human evolution and the formation of modern human populations. Both the origin and diversification of modern humans have been stressed. Some studies further trigger the debaters on the Upper Cave Man concerning its evolutionary level and its role in the formation of modern human populations in East Asia. To further explore these problems, we examined and compared 12 non-metric features on the 3 Late Pleistocene Upper Cave skulls and 162 Holocene individuals earthed from two archaeological sites of North China (Longxian and Yanqing). Our results indicate that 8 on the 12 features have different expression patterns between Upper Cave Man and recent Chinese leading the authors to believe that more primitive expressions appeared on the Upper Cave Man than on recent Chinese populations. Based on these findings, some problems on the intragroup variation in Late Pleistocene and Holocene populations are discussed.  相似文献   

18.
Deux types de diffuseurs en caoutchouc (Michelin) et en plastique polystratifié (Hercon®) sont testés en laboratoire pour étudier quelques aspects des phénomènes de diffusion. Trois composantes phéromonales, le Z9-12: Ac, le 12: Ac et le Z9-14: Ac imprégnées dans ces différents supports servent à détermineer le rôle joué par la longueur de la chaîne de la molécule et la présence de doubles liaisons sur la vitesse de diffusion. L'influence de la température, de la vitesse du vent et de l'humidité est déterminée en cellules climatisées.Parmi les facteurs relatifs à la structure chimique, l'influence de la longueur de la chaîne est prédominante par rapport à la présence d'une double liaison. Parmi les facteurs climatiques, le vent agit plus que la température sur la diffusion, alors que l'humidité paraît secondaire.  相似文献   

19.
Résumé Nos méthodes expérimentales permettent l'isolement d'une larve de sexe déterminé par hôte de l'ectoparasite grégaire Dinarmus vagabundus et du solaitire, D. basalis. Des hôtes porteurs de 3 à 8 larves par hôte de D. vagabundus sont aussi isolés. Dans ces conditions la quantité de nourriture disponible est la même pour toutes les densités larvaires étudiées.Les larves élevées en solitaire des deux espèces assimilent une quantité de nourriture significativement supérieure à celle assimilée par les . Ceci conduit à des adultes de poids moyen supérieur à celui des . Le poids moyen des et des de D. vagabundus diminue significativement aux fortes densités larvaires. L'intensité de la liaison entre la quantité de nourriture assimilée et la biomasse produite s'affaiblit au fur et à mesure que la densité larvaire par hôte augmente.Les de D. vagabundus de poids moyen (0,42 mg) engendrent deux fois et demi plus de descendants que les lilliputiennes (0,20 mg) émergées d'hôtes à forte densité larvaire. Celles de D. basalis (0,65 g) sont moins prolifiques que les de D. vagabundus.  相似文献   

20.
The Early Pleistocene locality at Venta Micena (Orce, Guadix-Baza basin, province of Granada, Spain) has provided four fossil remains - skull fragment VM-0, and long bone diaphyses VM-1960, VM-3691, and VM-12000 - which have been tentatively attributed to the hominids. Although several methodologies have been used to ascertain the human affinities of these specimens - including anatomical, morphometric and immunological analyses - the results obtained have not been conclusive, instigating a persistent debate. A taphonomic approach is used here for estimating the probability that a taxon the size of Homo sp. (~ 50 kg) could be represented in the fossil assemblage by four bone fragments and no tooth remain. A least-squares regression analysis between the percentage of teeth and the body mass estimated for each taxon of large mammals (N = 20) predicts a raw abundance of six teeth for Homo sp. in the assemblage. Given that up to the present moment no tooth remains attributable to the hominids has been unearthed during systematic excavations in the Venta Micena quarry, which has provided more than 15,000 fossils of large mammals, this argues strongly against the possibility that the three bone specimens could belong to Homo sp. The phalanx CV-0 from the Early Pleistocene site of Cueva Victoria (Cartagena, Spain) has also been attributed to the genus Homo. The taxonomic assignment of this specimen is biased, however, because it was not compared with Theropithecus oswaldi, the only primate species actually recorded from this karstic locality. A comparative anatomical and morphometric analysis of fossil and modern specimens of Theropithecus suggests that CV-0 can be attributed to T. oswaldi. As a result, Cueva Victoria does not contribute additional information concerning the first human settlements in Europe. By these reasons, apart from the paleoanthropological and archaeological findings from Atapuerca (TD lower levels and Sima del Elefante), the rich archaeological assemblages from Barranco León and Fuente Nueva-3 in Orce, dated 1.3-1.2 Myrs, which include fourteen hundred stone tools of Oldowan technology, constitute at present the only unequivocal evidence of human presence in Southeast Spain during Early Pleistocene times.  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