ISSN:0883-6353    

DOI:10.1002/gea.3340010101

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe oceanographic phenomenon known as El Niño is the subject of intensive recent study. Any hypotheses regarding physical causes and predictability of El Niño should consider its geological history.New geoarchaeological evidence suggests that the El Niño phenomenon did not exist along the northern and central coasts of Peru before about 5000 years B.P. Molluscan faunas from archaeological sites at Pampa las Salinas and Salinas de Chao permit temporal bracketing of a major structural change in the East Pacific water mass. The boundary between the warm Panamic Province and the cold Peruvian Province, which today occurs at about 5 degrees south latitude, was some 500 km further south from at least 11,000 years B.P. to about 5000 years B.P. This conclusion is corroborated by many other lines of evidence including phosphorite distribution, timing of glacial retreat, sea level change, radiolarian, diatom and fish scale distributions, and beach ridge patterns. The present day arid coastal climate of north central Peru is probably a post‐5000 year B.P. development. Hunter–gatherer populations of the area would most likely have exploited more land‐based seasonal resources from grasslands and forests before 5000 years B.P., and relied less upon the diminished productivity of warm water maritime r

ISSN:0883-6353    

DOI:10.1002/gea.3340010102

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractRecent work on the beach ridges at Santa, Peru (9° s latitude) upholds an earlier hypothesis, based on sedimentary evidence, that the ridges were formed by massive sediment pulses during rains associated with major incursions of the warm water El Niño countercurrent. The ridges can therefore be used to date major El Niño events. The alternate hypothesis for the Santa ridge origin cited minor sequential uplift as the causal factor; this hypothesis has been disproven, though one previously unreported uplift event at about 4200 years B.P. has been identified at Santa. In general, landscape alteration processes such as El Niño floods and tectonic uplift affect human populations, and accurate chronologies of these events are necessary to interpret the archaeological record. Geoarchaeological research offers the key to constructing landscape alteration chronologies, which are also of use to geologists for studies of earthquake prediction, sedimentation processes, and paleoclimatol

ISSN:0883-6353    

DOI:10.1002/gea.3340010103

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractRecent construction of a 10 × 3 irrigation canal across the Batán Grande–Poma archaeological complex of northern Peru provided an opportunity for inspection of soil profiles and detailed sampling along a five km transect bisecting an important concentration of ceremonial structures built during the past 3000+ years. From laboratory analysis of 80 soil samples we conclude no long‐term irrigation agriculture was practiced in this area and it was unimportant as a resource base. Stratigraphic studies indicate few sediments survive from the 1925 El Niño event, but a massive bed attributable to prehistoric slack‐water flood sediments has been identified and can be bracketed between ca. A. D. 650–1000 by associated diagnostic funerary ceramics. Other flood deposits representing the same or different events are described, but we conclude intervalley correlations will be difficult until more precise dating methods are

ISSN:0883-6353    

DOI:10.1002/gea.3340010104

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractArchaeological data from the lower Red River in Louisiana indicate that the modern course of the river is 1200 years older than previously suggested. Geologists claim a diversion of Red River through Moncla Gap approximately 500 to 1000 years ago. Marksville period occupations dating prior to A.D. 200 are identified at archaeological sites adjacent to the river below Moncla Gap. The position of these sites on Red River levees demonstrate that they post‐date the river's occupancy of the area. Extensive Marksville and later prehistoric occupations in the Moncla Gap area are seen as a direct result of the development of riverine environments resulting from this diversio

ISSN:0883-6353    

DOI:10.1002/gea.3340010105

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractA recent archaeological site survey of the island of Sanday on Orkney has identified a distinct concentration of 15 farm mounds. An immediate need is to determine the nature, age, and processes of formation of these very distinctive landform features. This paper reports a geoarchaeological investigation of three mounds at Westbrough, Langskaill, and Skelbrae. For the island as a whole, the mounds vary in diameter from 50 to 205 m, with deposits up to a thickness of 4.3 m. The mounds vary in their morphology, reflecting complex processes of accumulation, often intense disturbance, and in some cases, erosion by the sea. Sections at the three sites are described with analytical data also being given for particle size, percent loss‐on‐ignition, total phosphate, δ13C, and radiocarbon dating. The Westbrough and Skelbrae mounds were formed post‐7th century A.D.; more detailed dating was possible for the Langskaill site, which was initiated in the early to mid 13th century. A steady and relatively rapid sedimentation rate (ca. 1.9 cm year−1) took place over the 200 years following the initiation of the mound. The lower part of the Westbrough mound is distinguished by the presence of peat, interpreted as discarded bedding material, but the remainder of the investigated sections are composed dominantly of mineral sediments containing organic matter of terrestrial origin. It is suggested that these materials accumulated from the ash of domestic hearths as well as from the residues of bedding material from the byres (cattle sheds). Turves (vegetation plus some underlying soil) would have been cut, dried, and then used in the byres and such turves would have retained a significant mineral content. The implication is that the inherent fertility of the island made it unnecessary for the farmers to spread the dung over the fields. This may explain why there is the distinct concentration of these mounds on the island of Sanday, an island noted in earlier times for its fertile soils developed on calcareo

ISSN:0883-6353    

DOI:10.1002/gea.3340010106

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe late Quaternary history and systematics of slope erosion along a segment of the Central Israeli Coastal Plain is examined in conjunction with a series of terminal Paleolithic occupations. Three sites situated along the slope afford site‐specific and intersite data that enable reconstructions of local geological and archaeological sequences and correlations. The earliest (Kebaran) component is located on the midslope while the later (Geometric Kebaran) is situated along the footslope. Paleotopographic relations and sediment analyses indicate that the later Geometric Kebaran deposits were derived from the paleosol developed on the midslope. Paleoenvironmental contexts at the sites reveal that the rich Kebaran soil is diagnostic of an ancient swamp and attendant moist interval. Concentrations of cultural debris along these fragile midslopes imply a density of occupation and impact that may have increased rates of degradation. Extensive as well as intensive utilization of the midslope is suggested. The occupation contrasts markedly with the later Geometric Kebaran sites which display minimal sedimentation and a broader range of site distribution. The site‐specific evidence and regional distribution patterns argue for more varied settlement, proportionately reduced site sizes, and consequently, reduced slope utilization towards the close of the Paleolit

ISSN:0883-6353    

DOI:10.1002/gea.3340010107

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

ISSN:0883-6353    

DOI:10.1002/gea.3340010108

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

ISSN:0883-6353    

DOI:10.1002/gea.3340010109

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY

ISSN:0883-6353    

DOI:10.1002/gea.3340010110

出版商:John Wiley&Sons, Inc.    

年代:1986

数据来源: WILEY