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 15 毫秒
1.
Published evidence of Oldowan stone exploitation generally supports the conclusion that patterns of raw material use were determined by local availability. This is contradicted by the results of systematic studies of raw material availability and use among the earliest known archaeological sites from Gona, Afar, Ethiopia. Artifact assemblages from six Pliocene archaeological sites were compared with six random cobble samples taken from associated conglomerates that record pene-contemporaneous raw material availability. Artifacts and cobbles were evaluated according to four variables intended to capture major elements of material quality: rock type, phenocryst percentage, average phenocryst size, and groundmass texture. Analyses of these variables provide evidence of hominid selectivity for raw material quality. These results demonstrate that raw material selectivity was a potential component of Oldowan technological organization from its earliest appearance and document a level of technological sophistication that is not always attributed to Pliocene hominids.  相似文献   

2.
3.
The Hadar paleoanthropological site in Ethiopia preserves a record of hominin evolution spanning from approximately 3.45 Ma to 0.8 Ma. An angular unconformity just above the ca. 2.95 Ma BKT-2 complex divides the sediments into the Hadar Formation (ca. 3.8-2.9 Ma) and the Busidima Formation (ca. 2.7-0.15 Ma). The unconformity is likely a response to a major tectonic reorganization in the Afar Depression, and activation of the As Duma fault near the Ethiopian Escarpment (west of Hadar) created a half-graben in which the Busidima Formation was deposited. The pattern and character of sedimentation in the region changed dramatically above the unconformity, as cut-and-fill channel conglomerates and silt-dominated paleosols that comprise the Busidima Formation stand in sharp contrast to the underlying deposits of the Hadar Formation. Conglomerate deposition has been related to both the perennial, axial paleo-Awash and ephemeral, escarpment-draining tributaries. Overbank silts have yielded fossils attributed to early Homo and Oldowan stone tools. Numerous tuffaceous deposits exist within the Busidima Formation, but they are often spatially limited, fine-grained, and reworked. Recent work on the tephrostratigraphic framework of the Busidima Formation at Hadar has identified at least 12 distinct vitric tephras and established the first geochemical-based correlations between Hadar and the neighboring project areas of Gona and Dikika. Compared to Gona and Dikika, where Busidima Formation sediments are exposed over large areas, the highly discontinuous sediments at Hadar comprise less than 40 m in composite section and are exposed over an area of <20 km2, providing only snapshots into the 2.7-0.15 Ma window. The stratigraphic record at Hadar confirms the complex depositional history of the Busidima Formation, and also provides important details on regional stratigraphic correlations and the pattern of deposition and erosion in the lower Awash Valley reflective of its tectonic history.  相似文献   

4.
The upper part of the Pliocene Hadar Formation, central Afar, Ethiopia, has yielded a 40% complete fossil hominid skeleton (A.L. 288-1, “Lucy”). This specimen is described in detail and selected measurements and illustrations are provided.  相似文献   

5.
The Early Stone Age sites of Gadeb (Ethiopian South-East Plateau) were excavated under the direction of Desmond Clark in the 1970s. Dated to between 1.45 and 0.7 Ma, Gadeb proved that humans had already occupied high altitude areas in the Lower Pleistocene. Despite the importance of the Gadeb sites, their lithic assemblages were never published in detail, and no review of the stone tools has ever been reported since the original 1970s study. This paper updates the information available on Gadeb by presenting a systematic review of the lithic technology of several assemblages. The objectives are to evaluate the technological skills of Gadeb knappers and to contextualize them into the current discussion of the origins of the Acheulean and its possible coexistence with the so-called Developed Oldowan in East Africa.  相似文献   

6.
The time interval between 3 Ma and 2 Ma marks several important transitions in human evolution, including the extinction of Australopithecus afarensis, the origin of the genus Homo, and the appearance of concentrated stone tool assemblages forming recognizable archaeological sites. The period also marks important changes in Earth’s climatic history, with the onset of northern hemisphere glaciation starting sometime between 2.8 Ma and 2.5 Ma, and it remains an unresolved question in paleoanthropology whether or not the global climatic events influenced in whole or in part, local terrestrial paleoenvironments in Africa and, through this, the course of human evolution.Changes in the terrestrial mammalian faunas of East Africa during this time interval are an important source of data about terrestrial paleoenvironments, and it has been argued that during this time period the mammalian faunas of Africa experienced a sudden pulse in the extinction and origination of taxa. The data corroborating this Turnover Pulse Hypothesis derive from both large mammal and micromammal data, though the fossil record of the former is much more abundant in this interval. New micromammal fossils recovered from ca. 2.4 Ma deposits at locality A.L. 894, low in the Busidima Formation in the Hadar study area of the Afar region, Ethiopia, reveal a significant faunal turnover when compared with previously published material from older 3.2 Ma micromammal assemblages from the Hadar Formation deposits. The results support the hypothesis of a major faunal transition, but larger sample sizes and more extensive temporal sampling are needed to refine the time and rate of change within this interval at Hadar.  相似文献   

7.
经过地质调查发现,鄂尔多斯乌兰木伦遗址石制品的原料来源于遗址周边的白垩系基岩砾石层中。通过与遗址周边4个调查点样品的比较表明,这些调查点的砾石在岩性、尺寸大小及保存状况等方面区别不大,乌兰木伦的原料主要来自于距遗址约2km的白垩系基岩砾石层中,可获性较好。此外,能选择性地利用不同的原料,体现出古人类对原料开发具有一定的组织性。  相似文献   

8.
9.
《Palaeoworld》2023,32(3):470-480
The Jurassic rocks exposed in the Blue Nile Basin (central western Ethiopia), particularly the thick, fossiliferous and widely distributed Antalo Limestone Formation (ALF) has recently been dated between early Callovian and late Tithonian based on the occurrence of calcareous nannofossils from the Mugher section near Dejen, Ethiopia. However, the top part of the ALF is not well exposed at Mugher; in this study, the top part of the ALF was sampled at the Kurar section (150 km north of Mugher). It yielded a nannofossil assemblage containing Helenea chiastia, whose first occurrence (FO) marks the base of the Tithonian NJT16a calcareous nannofossil subzone, and Faviconus multicolumnatus, whose FO is near the base of the NJ15b subzone and corresponds with the FO of the Tithonian zonal marker Polycostella beckmannii recorded at the Mugher section. This age is also corroborated by the presence of recently recorded calpionellids (Bonetinae subzone) and the presence of late Tithonian ammonites, Djurjuriceras cf. sinuosum Tavera and Oxylenticeras Spath from the Kurar section. Hence, the upper part of the ALF exposed at the Kurar and Mugher sections are of late Tithonian age, although at the Mertule Mariam section (60 km northwest of the Kurar section), late Berriasian calpionellids were recently found from the top part of the ALF.  相似文献   

10.
延岭地点处于东秦岭洛南盆地南洛河第二级阶地上,属盆地西部“四十里梁塬”中部,紧邻支流县河。2012年10~11月对该地点进行发掘,揭露面积251 m2,在地表耕土层和平整土地扰动层、原生黄土和古土壤层出土石料、石核、石片、各类修理的石器、断块、碎屑等不同类型石制品856件。延岭地点加工石制品的主要原料为附近河流阶地砾石堆积中的砾石,以石英为主,石英岩次之,石英砂岩、砂岩、火成岩、硅质岩等偶有使用。剥片方式主要为锤击法,偶见砸击法。石制品以小型为主。石器组合包括刮削器、尖状器、石锥、凹缺器、薄刃斧和手镐。遗址地层光释光年代学研究显示该地点埋藏石制品的地层形成于中更新世晚期至晚更新世早期,其中距今12~7万年之间的晚更新世早期为石制品埋藏最为丰富的时段。  相似文献   

11.
Two Hipparion species, H. forstenae and H. hippidiodus from Gaojiashan locality in the Linxia Basin, Gansu, China are described in this paper, with the first presence of the former in the Linxia Basin. The lower cheek teeth of Hipparion from Gaojiashan bear deep ectoflexids, and after comparisons to other Chinese Hipparion fossils with deep ectoflexids, the mandibles with deep ectoflexids on the lower premolars suggest their attributions to H. forstenae. The presence of a deep ectoflexid on p2 may be interpretable as an intraspecifically variable feature in H. forstenae, and can also be found in H. dermatorhinum. Besides the Hipparion material, at least 8 species of large mammals occur at the Gaojiashan locality, including Adcrocuta eximia, Chilotherium wimani, Shansirhinus ringstroemi, Eucladoceros cf. proboulei, Palaeotragus cf. coelophrys, Giraffidae gen. et sp. indet., and the previously studied Promephitis hootoni and Eostyloceros hezhengensis. Although the sample from Gaojiashan shares five species with the Yangjiashan fauna, the Gaojiashan fossil assemblage may date to the Baodean because of the presence of H. forstenae. The overall taxonomic composition of the Gaojiashan assemblage at least suggests an approximate Baodean age, which would imply survival of C. wimani into the Baodean of the Linxia Basin.  相似文献   

12.
《Comptes Rendus Palevol》2014,13(8):737-746
The spatial relationships of the Early Oldowan toolmakers with their environment have been so far addressed through raw material procurement analyses and the characterization of hominid habitat. This paper proposes to integrate these two approaches into a broader spatial analysis encompassing archaeological and environmental data (palaeontological, geological and isotopic data) from Member F and lower Member G of the Shungura Formation (Lower Omo Valley, Ethiopia). Heterogeneity in data resolution induces a multiscale approach with three levels of analysis. The level of occurrence complex allows focusing on the characterization of archaeological occurrences and on their environmental settings. The level of “study area” allows working on hominid habitats and on their raw material procurement behaviours. Finally, at the Shungura Formation scale, we can address temporal issues related to the evolution of spatial behaviours between Member F and the lower part of Member G, ca. 2.3 to 2 million years (Ma).  相似文献   

13.
Climate change alters regional water and carbon cycling, which has been a hot study point in the filed of climatology and ecology. As a traditionally “water-rich” region of China, Yangtze River Basin plays an important role in regional economic development and ecosystem productivity. However, the mechanism of the influence of climate change on water and carbon cycling has been received little attention. As a coupling indicator for carbon and water, the water use efficiency (WUE) is widely used, which indicates the water consumption for carbon sequestration in watershed and regional scale. A lot of studies showed that climate change has significantly affected the water resource and production of the ecosystems in Yangtze River Basin during the period of 1956–2006, when great climate variations were occurred. To better understand the alternation pattern for the relationship between water and carbon cycling under climate change at regional scale, the WUE and the spatiotemporal variations patterns were simulated in the study area from 1956 to 2006 by using the Integrated Biosphere Simulator (IBIS). The results showed that the WUE spatial pattern had the annual and seasonal variations. In general, the average annual WUE value per square meter was about 0.58 g C/kg H2O in Yangtze River Basin. The high WUE levels were mainly distributed in the eastern area of Sichuan, western area of Jiangxi and Hunan, and the highest value reached 0.88 g C/kg H2O. The lowest WUE’s were mainly located in the western area of Sichuan and Qinghai with the lowest values reaching to 0.36 g C/kg H2O. The WUE in other regions mostly ranged from 0.5 to 0.6 g C/kg H2O. For the whole study area, the annual WUE slowly increased from 1956 to 2006. The WUE in the upper reaches of Yangtze River increased based on the simulated temporal trends, which mainly located in the western area of the Sichuan Basin; the WUE of the middle reaches of Yangtze River had increased slightly from 1987 to 1996, and then decreased from 1996 to 2006; the lower reaches of Yangtze River always had smaller WUE’s than the average from 1956 to 2006. The spatiotemporal variability of the WUE in the vegetation types was obvious in the Yangtze River Basin, and it was depended on the climate and soil conditions, and as well the disturbance in its distribution areas. The temporal variations of WUE among different vegetation types had similar trends but different in values. The forest type had higher WUE than any other vegetation types ranging from 0.65 to 0.8 g C/kg H2O. The WUE of shrubland ranged from 0.45 to 0.6 g C/kg H2O. The WUE of tundra was the lowest, indicating the differences in plant physiology. The consistence of the spatial pattern of WUE with the NPP indicated that the regional production of Yangtze River Basin increased based on the water resources prompted and vegetation restoration. We found the drought climate was one of critical factor that impacts the alteration of WUE in Yangtze River Basin in the simulation.  相似文献   

14.
Opisthorchis viverrini is one of the most common and medically important food-borne parasites in the Lower Mekong area of Southeast Asia. As we learn more about its ecology, pathology and epidemiology we see the need to consider more deeply the socio-cultural dynamics with which food-borne species complexes are associated. This paper argues that the Mekong region is characterized by strong livelihoods and life-style associations within wetland ecosystems, which are inseparable from human eating habits (“raw attitudes”). Within the fish-rice economies of the region there are many long-cherished food cultures based on eating raw, semi-cooked and fermented fish dishes, which are known to lead to opisthorchiasis, and potentially cholangiocarcinoma. This paper examines evidence from northeast Thailand showing that dedicated health outreach campaigns do help to reduce prevalence of opisthorchiasis over time. For disease prevention and health education approaches to be most effective, they must be sensitive to culture, livelihood economics, gender, and age. Further integrative, inter-disciplinary and international research must incorporate the complex dynamics of parasite ecology, human behavior, socio-economics, and public health awareness.  相似文献   

15.
We present a preliminary predictive model of Oldowan stone artefact and scavenged larger mammal bone assemblages for 11 landscape facets modeled earlier to occur across a large portion (>300 km2) of the paleo-Olduvai Basin during lowermost Bed II times. This second phase of model-building is based on our earlier characterizations of the basin's landscape ecostructure and the inter-facet distribution of key resources and hazards probably encountered by Late Pliocene hominids (Peters & Blumenschine, 1995, 1996). Our current extension of the model of hominid–landscape interactions specifies additional theoretical components, including: (1) the assumed capabilities of Oldowan hominids (presumablyHomo habilis, primarily); (2) the landscape-facet-specific tasks they carried out; (3) the immediate stone and bone task residues they produced; and (4) the predicted composition, condition, density, and clustering of stone artefact and butchered and unbutchered bone assemblages for each facet. We develop ecological linkages between these new and formerly reported modeling components, the most fundamental of which is the facet-specific degree of tree/shrub cover abundance, and the correlated degree of competition among larger carnivores and hominids for scavengeable larger mammal carcasses. These factors condition variability among landscape facets in scavenging opportunities encountered by hominids, which in our model is the major predictor of bone and stone artefact assemblage composition. The predictive value of scavenging reflects the bias of paleoanthropological traces toward technology and butchery in their landscape context, but the model is surprisingly insensitive to what are usually thought to be critical social components of hominid land use. The predictions for the traces of hominid–landscape interactions modeled herein can be tested in the future against the landscape archaeological sample being excavated from lowermost Bed II by the Olduvai Landscape Paleoanthropology Project.  相似文献   

16.
Pontian deposits of the Zagorje Basin constitute a coarsening-upward succession, which reflects the infilling style of this Pannonian sub-basin, i.e. the progradation of clastic systems into the brackish lake. Six facies differentiated correspond to lake floor, channelled slope, distal and proximal pro-delta, distal and proximal mouth bars, and lagoon/bay to swamp and alluvial environments. The deposition in the mouth-bar area was dominated by frictional forces. The upper-stage plane-bed sands are the main mouth-bar facies, which is uncommon in the geological record. The main factors for the origin of such bars include an abundant sand supply by the high-energy fluvial system(s), low-energy of the receiving basin and shallow depositional depth. Prolonged, catastrophic floods generated sustained hyperpycnal flows, which bypassed the mouth-bar area and fed the slope/pro-delta. The high ratio between sediment supply and subsidence rate resulted in a fast moving progradational wave, which involved the entire SW Pannonian Basin, including the Zagorje Basin.  相似文献   

17.
《Palaeoworld》2016,25(2):212-238
Mesozoic strata are well developed and exposed continuously across the Sichuan Basin, South China. In particular, the Upper Triassic strata yield diverse and abundant spore-pollen fossils, providing a significant reference for the study of palaeoenvironmental variations across the Triassic–Jurassic transition where mass extinctions were occurring. In this paper, we summarize the major progress on Late Triassic palynological studies in this basin. To date, 151 genera (454 species) of sporomorph fossils have been reported from the Late Triassic strata in the Sichuan Basin. Three palynological assemblages are distinguished for the Late Triassic in the Sichuan Basin. Late Triassic vegetation in the Sichuan Basin shows a remarkable predominance of ferns, followed by conifers and cycads/ginkgophytes, and conifers show a distinct increase in abundance in the latest Triassic. In general, the Late Triassic palaeoclimate in the Sichuan Basin was tropical-subtropical, humid and warm. A synthesis of the data shows that the Late Triassic did not have a constant palaeoclimate in the Sichuan Basin, several climatic events are recognized: two warm and humid climate events in Norian-Rhaetian time, coupled with a cooler and drier condition in the latest Late Triassic. Further investigations in higher resolution at more continuous sections in the Sichuan Basin are needed to better understand the Late Triassic vegetation response, climate changes, as well as palaeoecosystem variations across the Triassic–Jurassic boundary.  相似文献   

18.
In this paper, some results of the study on the sporepollen of the Yanghugou Formation in the western Shaan-Gan-Ning (Ordos) Basin of Northwest China axe reported. Plenty of well preserved microfossil, which 136 types belong to 62 microspore genera and one megaspore genus, including 2 new genera , 13 new species, I Acritarch (Chamosphaera pseudozonatus gen. et sp. nov.), from 8 bore-holes and outcrop have been discribed. In generally, the microfiora of the Yanghugou Formation is similar to the Taiyuan Formation (Upper Carboniferous). According to the spore-pollen assemblage of Yanghugou Formation may correlate with those in the Middle Carboniferous of Great Britain, Belgium the north of France, German and North America. Besides, the assemblage are similar to Middle Carboniferous of Nortth Shandong and Hengshanbu of Ningxia in the microfossil assemblage. The geological age of the beds is considered to Late of Middle Carboniferous.  相似文献   

19.
Fossil pollen grains extracted from sediments sampled from OGS-6a and OGS-7, two newly excavated Late Pliocene sites of Gona, in the Afar Depression of Ethiopia, indicate a high percentage of afromontane forest and highland taxa (36.8-43.3%), among which Podocarpus cf. gracilor is dominant (19.6-24.2%). Forest taxa typical of the afromontane phytogeographic region have also been identified in the samples. The overall pollen spectrum suggests a mosaic of open and closed habitats, with a considerable wooded environment present during the time associated with the beginnings of early hominid use of flaked stones at Gona. Here we provide details of the results from the pollen analyses. The two sites lie 4-8 m directly below a volcanic tuff dated by 40Ar/39Ar to 2.53 ± 0.15 million years (Ma). The materials were recovered within fine-grained sediments located just above a geomagnetic polarity transition identified as the Gauss-Matuyama boundary dated close to 2.6 Ma, also corroborating the earlier age reported for the East Gona artifacts from EG-10 and EG-12. Thus, the stone artifacts, fossilized broken fauna and pollen grains from OGS-6a and OGS-7 represent archaeological materials from the world's oldest securely dated sites, and offer insights on aspects of the palaeoenvironments around the time of the beginnings of ancestral hominid use of flaked stones, ca. 2.6 Ma.  相似文献   

20.
Tao Deng 《Geobios》2005,38(3):301
A well-preserved skull and articulated mandible of Shansirhinus, a horned aceratherine rhinocerotid, is described from an Early Pliocene (Gaozhuangian; approximately 5.3-4.34 Ma) locality of the Linxia Basin in Gansu, China. Comparing the new material of Shansirhinus ringstromi Kretzoi, 1942, we confirm the synonymy proposed previously for the species Chilotherium yunnanensis Tang et al., 1974, Chilotherium cornutum Qiu and Yan, 1982, and Ch. tianzhuensis Zheng, 1982. New knowledge concerning its cranial and mandibular morphology allows insight into its phylogenetic position among aceratherine rhinocerotids. A sister group relationship between Shansirhinus and Chilotherium is proposed on the basis of cranial, mandibular and dental evidence. Shared derived characters that support this relationship include: an expanded mandibular symphysis with a concave ventral surface; retracted premaxillae lacking upper incisors; a robust and right-angled facial crest; a flat or slightly concave dorsal skull profile; a weak or absent parastyle fold; and a constricted protocone on the premolars. Shansirhinus was probably a grazer, which is evidenced by the high crown, strong wear, well-developed secondary folds, and enamel plications on its teeth. The age of S. ringstromi is Late Miocene to the Early Pliocene, corresponding to the Turolian to Ruscinian, MN12-MN15 of Europe. S. ringstromi is likely the ancestor of the more advanced S. brancoi (Schlosser, 1903).  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