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1.
Henry DO 《Science (New York, N.Y.)》1994,265(5170):336-341
Research in the mountains of southern Jordan resulted in the discovery of 109 archaeological sites that are from the Lower Paleolithic to the Chalcolithic period [150 to 6 thousand years ago (ka)]. Beginning with the Middle Paleolithic (70 ka) two site types (long-term and ephemeral camps) are recognized. Long-term sites have larger areas, thicker deposits, higher artifact densities, and more abundant archaeological features than ephemeral sites. Their natural settings (elevation and exposure) and associated seasonal evidence (phytolith and cementum increment data) indicate that long-term sites were occupied during the winter, wet season and ephemeral sites during the warm, dry season. These differences in site use and seasonality likely reflect an adaptive strategy of transhumance that persisted to modern Bedouin times. At the end of the Pleistocene, the onset of warmer, drier conditions induced a shift of the long-term winter camps from relatively low (800 to 1000 meters above sea level) to high (1000 to 1250 meters above sea level) elevations and largely reversed the earlier transhumant pattern. 相似文献
2.
Pappu S Gunnell Y Akhilesh K Braucher R Taieb M Demory F Thouveny N 《Science (New York, N.Y.)》2011,331(6024):1596-1599
South Asia is rich in Lower Paleolithic Acheulian sites. These have been attributed to the Middle Pleistocene on the basis of a small number of dates, with a few older but disputed age estimates. Here, we report new ages from the excavated site of Attirampakkam, where paleomagnetic measurements and direct (26)Al/(10)Be burial dating of stone artifacts now position the earliest Acheulian levels as no younger than 1.07 million years ago (Ma), with a pooled average age of 1.51 ± 0.07 Ma. These results reveal that, during the Early Pleistocene, India was already occupied by hominins fully conversant with an Acheulian technology including handaxes and cleavers among other artifacts. This implies that a spread of bifacial technologies across Asia occurred earlier than previously accepted. 相似文献
3.
Middle Paleolithic assemblages from the Indian subcontinent before and after the Toba super-eruption
Petraglia M Korisettar R Boivin N Clarkson C Ditchfield P Jones S Koshy J Lahr MM Oppenheimer C Pyle D Roberts R Schwenninger JL Arnold L White K 《Science (New York, N.Y.)》2007,317(5834):114-116
The Youngest Toba Tuff (YTT) eruption, which occurred in Indonesia 74,000 years ago, is one of Earth's largest known volcanic events. The effect of the YTT eruption on existing populations of humans, and accordingly on the course of human evolution, is debated. Here we associate the YTT with archaeological assemblages at Jwalapuram, in the Jurreru River valley of southern India. Broad continuity of Middle Paleolithic technology across the YTT event suggests that hominins persisted regionally across this major eruptive event. 相似文献
4.
The evidence presented here indicates that man lived in the eastern part of the Beringian refugium before the peak of the late Wisconsin glaciation (27). He had sharp, stone tools intended for working bone and means of breaking large mammoth bones. Probably he hunted mammoth and caribou, and prepared the skins of the caribou for use as clothing and perhaps shelter. It is possible that he migrated to southern North America, although evidence for the presence of man there prior to the peak of the Wisconsin glaciation is at present in dispute (28). We do not know whether his culture should be classified as Mousteroid or Aurignacoid in Müller-Beck's scheme (23), whose criteria are taken from stone implements of which we have none, although we infer their presence. Our data suggest that in Beringia, and therefore probably in Siberia and the Far East, the transition from Middle Paleolithic to Upper Paleolithic levels of technology occurred at a relatively early date. This raises the larger question: Did the transition from Middle to Upper Paleolithic occur simultaneously in many parts of the world, or did it begin in and spread from one area (23)? 相似文献
5.
Pressure flaking has been considered to be an Upper Paleolithic innovation dating to ~20,000 years ago (20 ka). Replication experiments show that pressure flaking best explains the morphology of lithic artifacts recovered from the ~75-ka Middle Stone Age levels at Blombos Cave, South Africa. The technique was used during the final shaping of Still Bay bifacial points made on heat-treated silcrete. Application of this innovative technique allowed for a high degree of control during the detachment of individual flakes, resulting in thinner, narrower, and sharper tips on bifacial points. This technology may have been first invented and used sporadically in Africa before its later widespread adoption. 相似文献
6.
The Middle Paleolithic of Central Asia is little known and less understood. Several sites have been excavated in Soviet Central Asia, but few have been adequately presented. Recent excavations in north Afghanistan may throw new light on the problem because of the size of the rock shelter involved and its relative geologic dating. 相似文献
7.
Interdisciplinary study of a Paleolithic site at Budi?o, Louro Valley (province of Pontevedra), Spain, shows the presence of various tool-making techniques and types of tools in a single undisturbed site complex found in situ within Middle Würm colluvial deposits. 相似文献
8.
Jelinek AJ 《Science (New York, N.Y.)》1982,216(4553):1369-1375
Recent excavations at the deeply stratified Late Pleistocene cave site of Tabun on Mount Carmel have, yielded a long sequence of Middle and Lower Paleolithic industries and associated geological and environmental evidence that has important implications for the understanding of man's cultural and biological development in that period. An analysis of these materials strongly supports a continuity in cultural development at this site from about 130,000 to 50,000 years ago and suggests that a continuous biological evolution from Neandeithal to anatomically modem Homo sapiens took place in the southern Levant. 相似文献
9.
The Ushki Paleolithic sites of Kamchatka, Russia, have long been thought to contain information critical to the peopling of the Americas, especially the origins of Clovis. New radiocarbon dates indicate that human occupation of Ushki began only 13,000 calendar years ago-nearly 4000 years later than previously thought. Although biface industries were widespread across Beringia contemporaneous to the time of Clovis in western North America, these data suggest that late-glacial Siberians did not spread into Beringia until the end of the Pleistocene, perhaps too recently to have been ancestral to proposed pre-Clovis populations in the Americas. 相似文献
10.
For the first time, Gonyaulax excavata cysts have been shown to be toxic. Bottom sediments from a water depth of 90 meters off the Maine coast were extremely rich in cysts, which were approximately ten times more toxic than the corresponding motile stages. Cysts are probably ingested by shellfish, thereby causing shellfish toxicity in deeper waters offshore and contributing to shellfish toxicity in shallower coastal waters. A new approach to the problem of paralytic shellfish poisoning is therefore needed, one that takes into account benthic cysts and sedimentary factors affecting their distribution. The possible dangers of spreading poisoning through human activities must be considered. 相似文献
11.
青岛市贝类汞污染特征研究 总被引：1，自引：0，他引：1
[目的]调查青岛市贝类产品汞含量状况,分析其潜在健康风险。[方法]根据贝类的消费量并兼顾品种多样性的原则,在青岛市海产品批发市场共采集11种75份贝类样品,并分析其汞含量。[结果]青岛市贝类汞含量为0.001 3~1.291 4 mg/kg,平均含量0.071 8mg/kg,在采集的62份样品中有5份超过中国国家标准规定的海产品中总汞0.3 mg/kg(GB2762-1994)的限量值,超标率为8.1%。在经过检测的品种中,文蛤、缢蛏、魁蚶等品种平均含量较高,而杂色蛤仔含量则较低。与其他地区比较,青岛贝类汞含量是东营地区汞含量的37.1%,但比龙口高出1.85倍,也高于浙江及泉州地区贝类汞含量。[结论]我国胶州湾一带的海域已受到了较为严重的汞污染,应该引起有关部门的重视。 相似文献
12.
Pitulko VV Nikolsky PA Girya EY Basilyan AE Tumskoy VE Koulakov SA Astakhov SN Pavlova EY Anisimov MA 《Science (New York, N.Y.)》2004,303(5654):52-56
A newly discovered Paleolithic site on the Yana River, Siberia, at 71 degrees N, lies well above the Arctic circle and dates to 27,000 radiocarbon years before present, during glacial times. This age is twice that of other known human occupations in any Arctic region. Artifacts at the site include a rare rhinoceros foreshaft, other mammoth foreshafts, and a wide variety of tools and flakes. This site shows that people adapted to this harsh, high-latitude, Late Pleistocene environment much earlier than previously thought. 相似文献
13.
为了解海口湾贝类重金属的污染状况,对海口湾的牡蛎、文蛤体中重金属质量含量进行了测定。结果表明：海口湾牡蛎体中Zn,Cu,Cd,Pb,Cr重金属的质量含量分别为101．750,161．751,0．686,1．200,2．993mg·kg-1。文蛤体中Zn,Cu,Cd,Pb,Cr重金属的质量含量分别为14．060,1．155,0．071,0．145,0．225mg·kg-1。文蛤斧足、外套膜和闭壳肌、内脏团中Zn,Cu,Cd,Pb,Cr等5种重金属的质量含量均呈现由低到高的趋势。海口湾贝类样品重金属污染指数较小,环境质量优良;对贝类组织器官选择性食用将大大降低危害健康的风险。 相似文献
14.
15.
2009-2010年对浙江沿岸三门湾、乐清湾和嵊泗海水贝类养殖区采样151批次,连续2年监测了贝类微生物、贝类毒素和重金属有毒有害物质的污染状况。结果表明浙江沿岸贝类产品尚存在一定风险,部分样品有贝类毒素检出或重金属含量超标现象,应引起贝类消费者和相关渔业管理部门的重视。 相似文献
16.
参照测定人体心电图的标准Ⅱ导联,研究了鲤、蛙、龟、蛇、鸡、马、驴、西门塔尔牛、湖羊、细毛羊、梅花鹿、驼、猪、犬、猫、小白鼠、家兔和人等五大类17种具有代表意义的动物心电图,对其P波、QRS波、T波的形态学进行了比较分析,其结果表明:鲤、蛇的P波形态变异较大,且鲤P波与人类P波形态相反,有50％呈负向,其余动物的P渡与人类P波的形态相似,呈现以正向为主,鲫、蛙、龟、蛇的QRS波以R波为主波,其中鲤以QR波为主,蛙为RS波,龟、蛇以Rs波为主,鸡52％呈RS型,42％呈rS型,其余动物和人类均属于以R波为主的QRS波,同一种动物的QRS波可有各种形态出现,主要为QR、qR,qRs、Rs,RS、R波的QRS波型,蛙、蛇、猫、兔、猪、驴、驼等动物的T波与人类相似、呈现以直立为主,其他动物的形态则变异较大。 相似文献
17.
大连常江澳浮筏养殖贝类的饵料结构与浮游植物的关系 总被引：4，自引：0，他引：4
１９９５年６月２９日至１０月２２日对大连市金卵眍常江澳（大李家湾）浮筏贝类养殖水域及近岸海域进行了调查。研究了该海域养殖贝类的胃含物民浮游植物的种类组成、个体大小与数量分布情况,并对两者关系作了初步分析。结果表示,养殖贝类胃含物及肠道食物残余主要为硅藻和有机碎屑;海区浮游植物的种类组成和个体大小适宜贝类摄食;饵料生物的种类丰富、数量充足,适于贝类生长及养殖需求。 相似文献
18.
１９９５年６月２９日至１０月２２日对大连市金卵眍常江澳（大李家湾）浮筏贝类养殖水域及近岸海域进行了调查。研究了该海域养殖贝类的胃含物民浮游植物的种类组成、个体大小与数量分布情况,并对两者关系作了初步分析。结果表示,养殖贝类胃含物及肠道食物残余主要为硅藻和有机碎屑;海区浮游植物的种类组成和个体大小适宜贝类摄食;饵料生物的种类丰富、数量充足,适于贝类生长及养殖需求。 相似文献
19.
为了解粤东地区海水经济贝类重金属的污染现状及摄入健康风险,本研究采用电感耦合等离子体发射光谱法（ICP-AES）分别测定了10种海产经济贝类肌肉和内脏团中6种重金属（Zn、Cd、Pb、Cr、Cu及Mn）的质量分数,并采用单因子污染指数（Pi）、目标危险系数（THQ）及总目标危险系数（TTHQ）分别评价其污染程度和食用健康风险。结果表明,该10种贝类肌肉中重金属质量分数的平均值由高至低为Zn > Mn > Cu > Cr > Cd > Pb,内脏团中为Zn > Mn > Cu > Pb > Cr > Cd。除Cr外,贝类内脏团中其他5种金属质量分数的平均值均高于其相应的肌肉组织。Pi结果表明,除Cu外,贝类肌肉和内脏团均受Zn、Cd、Pb、Cr不同程度的污染,其中Cd的Pi最高,其次为Zn、Pb,而Cr指数相对较低;且大多数贝类内脏团中Cd、Zn及Pb的Pi值指示为重污染水平（即超标）。THQ评价结果显示,除了栉江瑶内脏团中的Cd外,该10种贝类中5种重金属暴露对儿童或成人没有明显的健康风险;但TTHQ结果表明,约有50%贝类的内脏团重金属TTHQ值大于1,表明暴露人群若长期食用这些贝类的内脏团将对健康产生负面影响。总之,粤东地区10种海水经济贝类分别受到Cd、Zn、Pb和Cr不同程度的污染,表明该地区海洋生态环境或贝类生产已存在重金属污染的安全隐患,建议加强该地区贝类产品重金属残留的质量监控及重金属污染的防控。 相似文献
20.
Study of 18 Cenozoic South Pacific deep-sea cores indicates an association of glacially derived ice-rafted sands and relatively low planktonic foraminiferal diversity with cooling of the Southern Ocean during the Lower Eocene, upper Middle Eocene, and Oligocene. Increased species diversity and reduction or absence of ice-rafted sands in Lower and Middle Miocene cores indicate a warming trend that ended in the Upper Miocene. Antarctic continental glaciation appears to have prevailed throughout much of the Cenozoic. 相似文献