Chronology of guitarrero cave, peru

Dating by accelerator mass spectrometry of wooden artifacts, cord, and charcoal samples from Guitarrero Cave, Peru, supports the antiquity of South America's earliest textiles and other perishable remains. The new dates are consistent with those obtained from disintegration counters and leave little doubt about the integrity of the lower Preceramic layers and their early cultivars. Re-evaluation of the mode of deposition suggests that most of the remains resulted from short-term use of the cave in the eighth millennium B.C., with a possible brief human visit as early as 12,560 years ago.     

Cotton remains from archeological sites in central coastal peru

Cotton remains from four archeological sites in central coastal Peru, representing a time sequence from about 2500 to 1000 B.C., were compared with similar materials obtained from living wild and cultivated forms of Gossypium barbadense L. The comparison revealed that the archeological cotton samples were primitive forms of Gossypium barbadense, differing little from present-day wild forms of the same species. Although not the earliest cottons recorded for the New World, they appear to represent the earliest stages of cotton domestication yet recorded.     

Early central andean metalworking from mina perdida, peru

Copper and gold artifacts in contexts dated to approximately 3120 to 3020 carbon-14 years before the present ( approximately 1410 to 1090 calendar years B.C.) recovered in excavations at Mina Perdida, Lurin Valley, Peru, show that artisans hammered native metals into thin foils, in some cases with intermediate anneals. They gilded copper artifacts by attaching gold foil. The artifacts show that fundamental elements of the Andean metallurgical tradition were developed before the Chavin horizon, and that on the Peruvian coast the working of native copper preceded the production of smelted copper objects.     

Uranium series dating of human skeletal remains from the del mar and sunnyvale sites, california

Uranium series analyses of human bone samples from the Del Mar and Sunnyvale sites indicate ages of 11,000 and 8,300 years, respectively. The dates are supported by internal concordancy between thorium-230 and protactinium-231 decay systems. These ages are significantly younger than the estimates of 48,000 and 70,000 years based on amino acid racemization, and indicate that the individuals could derive from the population waves that came across the Bering Strait during the last sea-level low.     

Megafauna and man from ayacucho, highland peru

Crude unifacial tools, choppers, and a burin have been uncovered in association with megafauna in a buried stratum that was radiocarbon dated at 12,200 B.C. in a cave in highland Peru. The tool types, megafauna, and date are significant with regard to the problem of the antiquity of man and his culture in the New World.     

Bismuth bronze from machu picchu, peru

The decorative bronze handle of a tumi excavated at the Inca city of Machu Picchu, Peru, contains 18 percent bismuth and appears to be the first known example of the use of bismuth with tin to make bronze. The alloy is not embrittled by the bismuth because the bismuth-rich constituent does not penetrate the grain boundaries of the matrix phase. The use of bismuth facilitates the duplex casting process by which the tumi was made and forms an alloy of unusual color.     

Early maritime economy and El Nino events at quebrada tacahuay, peru

The archaeological site of Quebrada Tacahuay, Peru, dates to 12,700 to 12,500 calibrated years before the present (10,770 to 10,530 carbon-14 years before the present). It contains some of the oldest evidence of maritime-based economic activity in the New World. Recovered materials include a hearth, lithic cutting tools and flakes, and abundant processed marine fauna, primarily seabirds and fish. Sediments below and above the occupation layer were probably generated by El Nino events, indicating that El Nino was active during the Pleistocene as well as during the early and middle Holocene.     

Late glacial stage and holocene tropical ice core records from huascaran, peru

Two ice cores from the col of Huascarán in the north-central Andes of Peru contain a paleoclimatic history extending well into the Wisconsinan (Würm) Glacial Stage and include evidence of the Younger Dryas cool phase. Glacial stage conditions at high elevations in the tropics appear to have been as much as 8 degrees to 12 degrees C cooler than today, the atmosphere contained about 200 times as much dust, and the Amazon Basin forest cover may have been much less extensive. Differences in both the oxygen isotope ratio zeta(18)O (8 per mil) and the deuterium excess (4.5 per mil) from the Late Glacial Stage to the Holocene are comparable with polar ice core records. These data imply that the tropical Atlantic was possibly 5 degrees to 6 degrees C cooler during the Late Glacial Stage, that the climate was warmest from 8400 to 5200 years before present, and that it cooled gradually, culminating with the Little Ice Age (200 to 500 years before present). A strong warming has dominated the last two centuries.     

Dated rock engravings from wonderwerk cave, South Africa

Radiocarbon dates associated with engraved stones from sealed archeological deposits at Wonderwerk Cave in the northern Cape Province indicate that rock engraving in South Africa is at least 10,000 years old.     

Olmec cave paintings: discovery from guerrero, Mexico

A cave in Guerrero, Mexico, investigated in 1968, contained previously unreported Olmec paintings. These paintings, some of the oldest known in Mesoamerica, are stylistically similar to Olmec art from the site of LaVenta, on Mexico's Gulf Coast, but contain several important glyphic motifs never previously known to have existed at this time level. The iconography of the paintings confirms several important hypotheses concerning basic concepts of Olmec religion; the cave itself was probably a shrine to water and fertility. Several pre-Hispanic textile fragments found in the cave are probably from a later culture period.     

A 1500-year record of tropical precipitation in ice cores from the quelccaya ice cap, peru

Two ice cores, covering 1500 years of climatic information, from the summit (5670 meters) of the tropical Quelccaya ice cap, in the Andes of southern Peru, provide information on general environmental conditions including droughts, volcanic activity, moisture sources, temperature, and glacier net balance. The net balance record reconstructed from these cores reflects major precipitation trends for the southern Andes of Peru. These records indicate extended dry periods between 1720 and 1860, 1250 and 1310, and 570 and 610; wet conditions prevailed between 1500 and 1720. Establishing a tropical precipitation record may help explain climatic fluctuations since the tropical evaporation-precipitation cycle is a principal mechanism driving the atmospheric circulation.     

Paleo-Indian remains from laguna de tagua tagua, central chile

Bone and stone tools associated with extinct fauna (horse and mastodon) place man's occupation in central Chile at 11,380 +/- 320 years ago.     

7500 years of prehistoric footwear from arnold research cave, missouri

Accelerator mass spectrometer dating of an assemblage of fibrous and leather footwear from Arnold Research Cave in central Missouri documents a long sequence of shoe construction by prehistoric Midwestern peoples, beginning perhaps as early as 8300 calendar years before the present (cal years B.P.). An earlier fibrous sandal form dates from 8325 to 7675 cal years B.P., and later fibrous or leather slip-ons span the period from 5575 to 1070 cal years B.P. The assemblage adds to a growing picture of the highly varied nature of prehistoric footwear production in the United States throughout the Holocene.     

贵州荔波干细洞和拉梭洞陆生动物群落结构与环境因子的关系

贵州省荔波县岩溶洞穴多,洞穴动物丰富,具有重要的科研价值。在洞穴生态系统中,洞穴动物是重要的生物类群,为探讨洞穴动物群落结构及其与环境的关系。本研究对荔波的干细洞（未受人类干扰）和拉梭洞（已受人类干扰）的洞穴动物进行了调查,并比较了两个洞穴的动物群落结构特征,应用主成分（PCA）法分析了动物群落结构与环境因子的关系。结果表明：干细洞共获动物536号,计56种,拉梭洞共获动物363号,计23种。多样性指数、丰富度指数、均匀度指数、优势度指数最高的分别是干细洞有光带群落（2.748 6）、干细洞有光带群落（6.733 8）、干细洞黑暗带群落（0.841 9）、拉梭洞黑暗带群落（0.395 5）;群落多样性指数和丰富度指数均沿有光带、弱光带、黑暗带呈递减趋势。群落间相似性指数偏低,除了群落E-F（0.428 5）、群落C-F（0.272 7）处于中等不相似水平,其余群落之间均处于极不相似水平。PCA分析表明,影响干细洞动物群落结构的主导因子为土壤营养元素（Na、K）、土壤有机质、气温、空气湿度和土壤湿度,影响拉梭洞动物群落结构的主导因子为土壤营养元素（Na、K）、土壤有机质、空气湿度、CO₂含量和滴水pH。研究可为洞穴动物的保护、生态资源可持续发展提供科学依据。     

A test of climate, sun, and culture relationships from an 1810-year Chinese cave record

A record from Wanxiang Cave, China, characterizes Asian Monsoon (AM) history over the past 1810 years. The summer monsoon correlates with solar variability, Northern Hemisphere and Chinese temperature, Alpine glacial retreat, and Chinese cultural changes. It was generally strong during Europe's Medieval Warm Period and weak during Europe's Little Ice Age, as well as during the final decades of the Tang, Yuan, and Ming Dynasties, all times that were characterized by popular unrest. It was strong during the first several decades of the Northern Song Dynasty, a period of increased rice cultivation and dramatic population increase. The sign of the correlation between the AM and temperature switches around 1960, suggesting that anthropogenic forcing superseded natural forcing as the major driver of AM changes in the late 20th century.     

Early tertiary age of pitchstone in the northern black hills, South dakota

A block of pitchstone in the northern Black Hills, South Dakota, is Paleocene in age, according to potassium-argon dating of biotite and fission-track dating of zircon in the sample. These data invalidate published suggestions that the age is much younger. The pitchstone is not extrusive in its present position but instead is in a volcanic pipe with other fragments that came downward from as much as 1100 meters above the modern surface.     

Marine lava cave fauna: composition, biogeography, and origins

An assemblage of endemic cavernicolous marine invertebrates, including taxa found on both sides of the Atlantic Ocean of great phylogenetic age or with affinities to deep sea organisms, inhabits the Jameos del Agua cave, a sea waterflooded Holocene lava tube cave on Lanzarote in the Canary Islands. This marine cave contains both relicts from Tethyan times, such as an apparently new crustacean family belonging to what had been the monotypic class Remipedia, and relicts of groups that are now common only in the deep sea as well as species that occur outside the cave.     

江苏高淳县蓰薛城遗址的植物蛋白石分析

薛城遗址地处江苏省西南与安徽省接壤的高淳县境内的石臼湖南岸。该遗址是 1 997年 8月初高淳县薛城乡卫生院在新建办公楼挖墙沟时发现的。当年 9月至 1 2月 ,江苏南京市文物局与高淳县文化局共同对薛城遗址进行了抢救性发掘。结果发现该遗址为一处新石器时代的文化遗址( 1) 。