Article

A Groundwater Hypothesis for the Origin of “Fire Areas” on the Northern Channel Islands, California

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  • Santa Cruz Island Foundation
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Abstract

Pleistocene areas of red sediments and carbonized vegetation on the Northern Channel Islands, California, have in the past been interpreted as caused by fires of either natural or human origin. Some are associated with darkened mammoth and bird fossils, and these fossils have been considered as having been burned by early man. Reevaluation of these so-called “fire areas” indicates that the above phenomena are the result of low-temperature (≤100°C), nonheating processes occurring in groundwater. Evidence for this conclusion is derived from field observations on fossil carbonized vegetation, and the geology of the areas. Additional evidence derives from experiments on the red sediments and fossil wood, X-ray diffraction analyses, magnetic analyses, studies on the clay minerals smectite and illite, and the demonstration that fossil mammoth bone contains sufficient Fe and Mn to account for their discoloration. Much of the carbonization of vegetation probably occurred in water rather than in fire. Radiocarbon dates from the islands will probably need to be reevaluated. These data provide evidence contrary to the concept of the occurrence of significant fires, either natural or set by early man, on the Northern Channel Islands.

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... Wendorf (1982:174) added to these descriptions noting that: " fire areas vary in size and shape from small marks 4 or 5 cm wide to elongated lenses several meters in length and as much as a meter in depth. " Cushing et al. (1986) suggested that some of the red zones could be the remnants of once continuous bands extending several meters to over 1 km. We have observed some thin lenses of reddened sediment extending more or less continuously for tens of meters, but most of the fire areas we have examined are generally more localized. ...
... Because many of the red zones were considerably older than initial human colonization of the Channel Islands (~ 13,000 cal yr BP) and the reported association of mammoth and other bones with the red zones was problematic (Wendorf, 1982; Cushing et al., 1986), researchers explored alternative hypotheses that were unrelated to human activities. Two hypotheses remain the dominant explanations for the origins of the red zones: natural fires and groundwater processes . ...
... Johnson et al. (1980) also suggested that the red zones were from natural fires. Cushing et al. (1986) presented an analysis of sediments, bones, and carbonized plant remains from red zones to test their hypothesis that the red zones were actually " ochreous areas " caused by groundwater processes that resulted in carbonization of plant materials, reddening of soils through iron oxidation, and discoloration of bones. Critical to their argument was the contention that the clay mineral smectite is irreversibly transformed to illite when heated to 200°C or higher. ...
Article
At the close of the Pleistocene, fire regimes in North America changed significantly in response to climate change, megafaunal extinctions, anthropogenic burning and, possibly, even an extraterrestrial impact. On California's Channel Islands, researchers have long debated the nature of late Pleistocene “fire areas,” discrete red zones in sedimentary deposits, interpreted by some as prehistoric mammoth-roasting pits created by humans. Further research found no evidence that these red zones were cultural in origin, and two hypotheses were advanced to explain their origin: natural fires and groundwater processes. Radiocarbon dating, X-ray diffraction analysis, and identification of charcoal from six red zones on Santa Rosa Island suggest that the studied features date between ~ 27,500 and 11,400 cal yr BP and resulted from burning or heating, not from groundwater processes. Our results show that fire was a component of late Pleistocene Channel Island ecology prior to and after human colonization of the islands, with no clear evidence for increased fire frequency coincident with Paleoindian settlement, extinction of pygmy mammoths, or a proposed Younger Dryas impact event.
... " In some instances, including a poorly documented locality at Running Springs on San Miguel Island, mammoth bones show clear evidence of burning. Research by Glassow (1980), Cushing et al. (1984, 1986), Wendorf (1982) , and others has suggested that these associations are probably the result of overturned burning trees or chemical changes in the soil rather than human cooking of mammoth remains. ...
... A classic example of how taphonomic studies have improved our interpretations of Channel Islands archaeology is Orr's (1968) ardent assertion that he had identified associations of human artifacts or agency with Pleistocene fauna, including pygmy mammoth remains dating to more than 40,000 years. Careful taphonomic studies of Orr's evidence suggests, however, that his fire areas were natural features caused by burning trees or chemical interactions in the soils (see Glassow, 1980; Cushing et al., 1984 Cushing et al., , 1986) and that other spatial associations were actually in secondary erosional exposures. Recent analysis of a bald eagle nest on Santa Rosa Island has also demonstrated that eagles transported large abalone shells and other marine fauna found in archaeological sites to their nests (Erlandson et al., 2003; Collins et al., 2005). ...
Article
Inhabited by humans for over 12,000 calendar years, California's Channel Islands contain thousands of archaeological sites, ranging from dense shell middens and villages to small lithic scatters and camps. Similar to many islands around the world, the Channel Islands have a dearth of burrowing animals and limited historical development leading to generally good preservation of archaeological constituents and relatively high stratigraphic integrity. Despite these favorable preservation conditions, numerous natural and cultural processes have impacted the island's archaeological record. Channel Islands archaeologists, however, have given relatively limited attention to the effects of taphonomic and formation processes. The authors provide an overview of taphonomic and formation processes affecting Channel Islands archaeology, illustrating the importance of regional taphonomic syntheses in the management, preservation, and interpretation of archaeological sites. These data also demonstrate the significance of detailing formation processes in islands and other areas where burrowing rodents and other disturbances are thought to be absent or limited. © 2006 Wiley Periodicals, Inc.
... An enduring research question on the Channel Islands has focused on the relationship between humans and pygmy mammoths. The pendulum has swung widely over the years, often paralleling trends in continental megafaunal extinction debates, between human overkill, climate change and, more recently, an extraterrestrial impact as the driving force of extinction (Agenbroad 2002Agenbroad , 2009 Agenbroad et al. 2005; Berger and Orr 1966; Cushing et al. 1986; Erlandson et al. 2004; Kennett et al. 2008; Orr 1968; Orr and Berger 1966). Beginning perhaps 200,000 years ago, Columbian mammoths swam to the northern Channel Islands, underwent a roughly 30 per cent size reduction (shrinking to just under a 2m average shoulder height) and gave rise to island pygmy mammoths (Agenbroad 2009: 16). ...
... Some twentieth-century researchers believed the northern Channel Islands were colonized by humans at least 40,000 years ago and associations between artifacts, 'fire features' and mammoth remains pointed towards a human-induced extinction (Berger and Orr 1966; Orr 1968; Orr and Berger 1966). The Americas are now thought to have been colonized during the last *15,000 years and careful scrutiny of some of these questionable associations suggests that most or all of the fire areas or 'mammoth roasting pits' were natural burn features or the result of groundwater processes (Cushing et al. 1986; Wendorf 1982). There is currently no direct evidence that Paleoindians hunted Columbian or pygmy mammoths on the Channel Islands. ...
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Explanations for the extinction of Late Quaternary megafauna are heavily debated, ranging from human overkill to climate change, disease and extraterrestrial impacts. Synthesis and analysis of Late Quaternary animal extinctions on California's Channel Islands suggest that, despite supporting Native American populations for some 13,000 years, few mammal, bird or other species are known to have gone extinct during the prehistoric human era, and most of these coexisted with humans for several millennia. Our analysis provides insight into the nature and variability of Quaternary extinctions on islands and a broader context for understanding ancient extinctions in North America.
... Understanding that carbonized wood is mostly material that decayed in situ, and that charcoal is the result of burning, the visual physical appearance suggests widespread sorting of microscopic charcoal in water. We have no data to suggest the source of wildfires, or whether they might be naturally or culturally generated (but see Cushing et al., 1986;Rick et al., 2012;Lightfoot et al., 2013). However, during microscope work and fossil picking, the senior author recognized certain cubic forms of very small charcoal-like fragments. ...
Article
Mollusk and ostracode assemblages from the distal Old River Bed delta (ORBD) contribute to our understanding of the Lake Bonneville basin Pleistocene-Holocene transition (PHT) wetland and human presence on the ORBD (ca. 13,000–7500 cal yr BP). Located on U.S. Air Force-managed lands of the Great Salt Lake Desert (GSLD) in western Utah, USA, the area provided 30 samples from 12 localities. The biological assemblages and the potential water sources using ⁸⁷ Sr/ ⁸⁶ Sr analyses showed wetland expansion and contraction across the PHT, including the Younger-Dryas Chronozone (YDC). The record reflects cold, freshwater conditions, which is uncharacteristic of the Great Salt Lake Desert, after recession of Lake Bonneville. Lymnaea stagnalis jugularis , Cytherissa lacustris , and possibly Candona sp. cf. C . adunca , an endemic and extinct species only reported from Lake Bonneville, suggest cold-water environments. Between 13,000–12,400 cal yr BP, a shallow lake formed, referred to as the Old River Bed delta lake, fed by Lake Gunnison, as shown by ⁸⁷ Sr/ ⁸⁶ Sr ratios of 0.71024–0.71063 in mollusk fossils collected at the ORBD, characteristic of the Sevier basin. These findings add paleoenvironmental context to the long-term use of the ORBD by humans in constantly changing wetland habitats between 13,000–9500 cal yr BP.
... 51,52 These roasting pits or "fire areas" left reddish soil stains, some containing animal bones and other materials, which were later determined to be the result of either natural wildfires that burned through an area, or less likely staining from groundwater processes. [53][54][55] Although the anthropogenic origins of the fire areas did not stand the test of time, more recent studies suggest that human-induced burning may have increased during the Late Holocene, particularly after about 4,000 years ago on the Channel Islands. 34 Charcoal data from sediment cores show an influx of charcoal during the Late Holocene that suggests an increase in fire that does not correlate with climatic changes, but does correlate with increased human presence and probable anthropogenic fires. ...
Article
Human-environmental relationships have long been of interest to a variety of scientists, including ecologists, biologists, anthropologists, and many others. In anthropology, this interest was especially prevalent among cultural ecologists of the 1970s and earlier, who tended to explain culture as the result of techno-environmental constraints. More recently researchers have used historical ecology, an approach that focuses on the long-term dialectical relationship between humans and their environments, as well as long-term prehuman ecological datasets. An important contribution of anthropology to historical ecology is that anthropological datasets dealing with ethnohistory, traditional ecological knowledge, and human skeletal analysis, as well as archeological datasets on faunal and floral remains, artifacts, geochemistry, and stratigraphic analysis, provide a deep time perspective (across decades, centuries, and millennia) on the evolution of ecosystems and the place of people in those larger systems. Historical ecological data also have an applied component that can provide important information on the relative abundances of flora and fauna, changes in biogeography, alternations in food webs, landscape evolution, and much more.
... This makes her a possible Clovis contemporary, but not a predecessor. Claims of association on Santa Rosa Island of ostensible artifacts and hearths with bones of pygmy mammoths, dated around 40,000-12,000 BP (Orr 1968), have not withstood close scrutiny (Stanford 1983:71;Waters 1985:132;Cushing et al. 1986). The first nearly intact skeleton of a pygmy mammoth was found on the island in 1994. ...
Article
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Ever since José de Acosta's prescient speculation, in 1590, that Native Americans were descended from “savage hunters” who had followed game animals across a land bridge from northeastern Asia into northwestern America (Acosta 1604), most serious scholars have assumed that this was the migration route. The main point of dispute has been the date when the ancestral Asians made the crossing. After many nineteenth-century claims of the discovery of stone tools or bones of “early man” failed to withstand scientific scrutiny, a conservative reaction set in, embodied by the hyper-skeptical Aleš Hrdlička of the Smithsonian Institution. Hrdlička dismissed all claims of a human presence in the Americas prior to about 5000 years ago.
... The investigations by Kirch and Yen (1982) on Tikopia Island in the eastern Solomon Islands allowed them to conclude that late Holocene emergence of the island was the product of both sea-level fall and increased amounts of terrigenous sediment being deposited on the coastal flats. Detailed surveys of "fire areas/' long believed to have been created by humans, on the northern Channel Islands off California led Cushing et al. (1986) to conclude that these were more likely the product of low-temperature, non-heating processes occurring in groundwater. The study by Spennemann (1987:91) on shellfish resources on Tongatapu Island in southern Tonga enabled him to demonstrate that the decreasing supply of large Anadara was "caused both by predation and (mainly) changing environment." ...
... Skeptics have pointed out that the reported artifactual associations have not been adequately documented, that all the dated materials seem to be redeposited, and there is no proof of human creation of the burned areas (Erlandson, 1994;Stanford, 1983, p. 71;Waters, 1985, p. 132). Wildfires or groundwater effects may account for the reddened soil and darkened bones (Cushing et al., 1986). In 1994, the first nearly intact skeleton of a pygmy mammoth was found on the island (Agenbroad et al., 1995). ...
Article
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The prevailing archaeological consensus on Paleoindian origins and colonization of the Americas has been shaken by recent wide acknowledgment of pre-Clovis occupation at Monte Verde, Chile, and by claims that ostensibly non-Mongoloid skeletal remains might represent a precursor population. Recent mitochondrial DNA studies have been interpreted by some as indicating an earlier and more complex peopling of the continent. This paper reviews the current archaeological and biological evidence, in America and northern Asia, for the origins of Native Americans, assesses models of the colonization process in the light of new data and a revised chronology, and suggests avenues for future research.
... The only question con cerns which interglacial beach it covers. Cooked elephant has been found in comparable alluvial covers on Santa Rosa Island (Orr and Berger 1966;Carter 1987;Berger 1971), despite chal lenges (Cushing et al. 1986; see Carter 1987 for a rebuttal). Berger reported finding a hearth with a mammoth leg in it that was accompanied by stone tools and abundant charcoal that was radio carbon deficient (greater than 40,000 years). ...
Article
The relatively stable, slowly uplifted San Diego coastal belt has preserved ancient landforms to an exceptional degree. Much of the area can be read as modified by a regressing sea throughout most of the Pleistocene. The glacial and inter­ glacial sea level changes left classic alluvial covers over low sea stand beaches and valley fills recording high sea stands. The latest coastal terrace alluvial covers over high sea stand beaches contain an archaeological record. The valleys have fills attributed to episodes of high sea stand, and an archeological record is found in these fills also. The record of human finely made scrapers, some bifacially flaked knives and some odd crescentic stones. Whether they had the mano and metate is controversial. In my view, they did (Carter 1977). They were succeeded by the La Jollan people after 8000 years ago. These people rarely used the fine-grained volcanics but instead depended on the inferior cobbles of quartzite and porphyry so abundant in the region. Instead of fine scrapers. they made crude ones. Bifacial knives of the San Dieguito type disappear. The metate was of great importance in their economy that emphasized seed gathering, much use of acorns, much small game, and moderate amounts of deer-sized game. On the coast there was much use of shell fish. (This is a cul­ tural decline. Or, perhaps a replacement of the earlier people by a culturally less advanced group). The historic people differed little from the preceding La Jollan people. They simply added pottery making and use of the bOw and arrow. They took up the practice of cremation in place of burial. The original way of life simply was carried on with little change. I have for some decades put forward a quite different picture (Carter 1950. 1951. 1952. 1957a. 1959. 1978, 1980). The Diegueno are the historic people, Yuman in speech and cultur­ ally enriched from the east, but otherwise little different from the La Jolla people who clearly preceded them in time. This, so far, is also the generally accepted view. Differences appear in treatment of the San Dieguito prob­ lem. They seem to me to be a very weak impulse reaching y. this area from the east, a pale reflection of the Clovis-Folsom revolution with its production of beautifully made stone points and with some emphasis on big game hunting, though even for the Great Plains and the East it is probable that the hunting • 1 has been over-emphasized. Perhaps few people brought these 1 advanced stone work techniques or perhaps it was only a weak i flow of ideas. At any rate. it died out leaving little mark on , the old life way.
... Most researchers initially accepted Orr's hypothesis that the discrete packages of discolored sediments he called fire areas were related to burn events (e.g., Johnson et al. 1980, Wendorf 1982. This hypothsis was eventually challenged by a group invoking a groundwater process to explain the features (Cushing et al. 1986, Cushing 1993. Although the groundwater hypothesis does not appear to have gained much support by researchers working on the islands, it wasn't until recently that Rick et al. (2012) used multiple lines of evidence, including clay mineralogy, to demonstrate that the fire areas were indeed the result of fire and not groundwater processes. ...
Article
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charcoal is relatively common in the Quaternary record on the California Channel Islands. Previous researchers have found charcoal in paleosols, eolian and alluvial sequences, and sediment cores dating to the late Pleistocene and Holocene on Santa Rosa, San Miguel, and Santa Cruz islands, among others (Orr 1968, Johnson 1977, Cole and Liu 1994, Anderson et al. 2009, Pinter et al. 2011b, Scott et al. 2011). For decades, researchers have been interested in understanding fire regimes on the Channel Islands and the role early humans might have had in using fire to transform the island landscapes (Orr 1968, Kennett et al. 2008, Pinter et al. 2011a, Erlandson et al. 2012, Rick et al. 2012). How-ever, assessing the role that humans have had in the fire history of the islands is made diffi-cult by the fact that both natural (lightning-induced) and anthropogenic fires leave behind similar evidence in the geologic record, espe-cially during times when human populations are relatively low. On mainland North America, humans have used fire since at least the late Pleistocene to clear land for cultivation, remove underbrush, drive or trap game, and alter plant communi-ties (Greenlee and Langenheim 1990, Keeley 2002, Bowman et al. 2009). Evidence for such activities goes back even further in time in
... Countering the anthropogenic mode of origin are 2 controversial but naturally occurring processes of origin. One of these is not related to fire at all, but proposes that the "fire" areas are simply zones of sediment alteration from groundwater (Cushing et al. 1986, Cushing 1993. However, the precise mechanism by which sediment can be simultaneously blackened and reddened in a short vertical distance by groundwater is not clear. ...
Article
Full-text available
Over a span of 50 years, native Californian Donald Lee Johnson made a number of memorable contributions to our understanding of the California Channel Islands. Among these are (1) recognizing that carbonate dunes, often cemented into eolianite and derived from offshore shelf sediments during lowered sea level, are markers of glacial periods on the Channel Islands; (2) identifying beach rock on the Channel Islands as the northernmost occurrence of this feature on the Pacific Coast of North America; (3) recognizing of the role of human activities in historic landscape modification; (4) identifying both the biogenic and pedogenic origins of caliche “ghost forests” and laminar calcrete forms on the Channel Islands; (5) providing the first soil maps of several of the islands, showing diverse pathways of pedogenesis; (6) pointing out the importance of fire in Quaternary landscape history on the Channel Islands, based on detailed stratigraphic studies; and (7), perhaps his greatest contribution, clarifying the origin of Pleistocene pygmy mammoths on the Channel Islands, due not to imagined ancient land bridges, but rather the superb swimming abilities of proboscideans combined with lowered sea level, favorable paleowinds, and an attractive paleovegetation on the Channel Islands. Don was a classic natural historian in the great tradition of Charles Darwin and George Gaylord Simpson, his role models. Don’s work will remain important and useful for many years and is an inspiration to those researching the California Channel Islands today.
... Most researchers initially accepted Orr's hypothesis that the discrete packages of discolored sediments he called fire areas were related to burn events (e.g., Johnson et al. 1980, Wendorf 1982. This hypothsis was eventually challenged by a group invoking a groundwater process to explain the features (Cushing et al. 1986, Cushing 1993. Although the groundwater hypothesis does not appear to have gained much support by researchers working on the islands, it wasn't until recently that Rick et al. (2012) used multiple lines of evidence, including clay mineralogy, to demonstrate that the fire areas were indeed the result of fire and not groundwater processes. ...
Article
Full-text available
Understanding how early humans on the California Channel Islands might have changed local fire regimes requires a baseline knowledge of the frequency of natural wildfires on the islands prior to human occupation. A sedimentary sequence that was recently discovered in a small canyon on San Nicolas Island contains evidence of at least 24 burn events that date to between ∼37 and 25 ka (thousands of calibrated 14C years before present), well before humans entered North America. The evidence includes abundant macroscopic charcoal, blackened sediments, and discrete packages of oxidized, reddish-brown sediments that are similar in appearance to sedimentary features called “fire areas” on Santa Rosa Island and elsewhere. Massive fine-grained sediments that contain the burn evidence are interpreted as sheetwash deposits and are interbedded with coarse-grained, clast-supported alluvial sediments and matrix-supported sands, pebbles, and cobbles that represent localized debris flows. These sedimentary sequences suggest that the catchment area above our study site underwent multiple cycles of relative quiescence that were interrupted by fire and followed by slope instability and mass wasting events. Our 14C-based chronology dates these cycles to well before the arrival of humans on the Channel Islands and shows that natural wildfires occurred here, at a minimum, every 300–500 years prior to human occupation.
... While early researchers reported that the Northern Channel Islands were colonized by humans at least 40,000 years ago and claimed an association between human artifacts and mammoth remains as well as what were interpreted as "fire features" Orr and Berger, 1966;Orr, 1968), closer scrutiny puts the date of the first occupation of the islands by humans at around 13,000 cal. BP), and what were interpreted as "mammoth roasting pits" are now thought to be natural burn features or due to other natural processes (Wendorf, 1982;Cushing et al., 1986;Rick et al., 2012;Pigati et al., 2014). ...
Article
Microwear analyses have proven to be reliable for elucidating dietary differences in taxa with similar gross tooth morphologies. We analyzed enamel microwear of a large sample of Channel Island pygmy mammoth (Mammuthus exilis) molars from Santa Rosa Island, California and compared our results to those of extant proboscideans, extant ungulates, and mainland fossil mammoths and mastodons from North America and Europe. Our results show a distinct narrowing in mammoth dietary niche space after mainland mammoths colonized Santa Rosa as M. exilis became more specialized on browsing on leaves and twigs than the Columbian mammoth and modern elephant pattern of switching more between browse and grass. Scratch numbers and scratch width scores support this interpretation as does the Pleistocene vegetation history of Santa Rosa Island whereby extensive conifer forests were available during the last glacial when M. exilis flourished. The ecological disturbances and alteration of this vegetation (i.e., diminishing conifer forests) as the climate warmed suggests that climatic factors may have been a contributing factor to the extinction of M. exilis on Santa Rosa Island in the Late Pleistocene.
... Fieldwork aimed at recovering data about fire should be focused on observing the setting of the site and its lithostratigraphy. For example, noting the shape, size, nature, and context of suspected burned zones may be helpful for deciding whether a reddened zone is the result of heating or diagenesis (Cushing et al. 1986;Pigati et al. 2014). ...
Article
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Everyone agrees that fire has played an important part in the history of the genus Homo. However, because of the sometimes ephemeral and ambiguous nature of the evidence for fire in the Paleolithic record, establishing when and how hominins actively interacted with fire has been difficult. Over the past several decades, multiple techniques have been developed and employed in the search for the origins of human use of fire. Because fire is a natural phenomenon, the identification of burned remains at an archaeological site is generally not considered to be, on its own, convincing evidence for human use of fire. Rather, much of the difficulty of identifying early evidence for fire use has hinged on the question of how to establish a more direct link between burned materials and human activity. Here, we advocate for an approach to the investigation of the history of hominin use of fire that emphasizes an integration of multiple techniques. In particular, we argue that a contextualized study conducted at the microscopic scale—what we call a microcontextual approach—shows the most promise for establishing a behavioral connection between hominins and fire in the archaeological record. © 2017 by The Wenner-Gren Foundation for Anthropological Research. All rights reserved.
... carbonized wood) and the humic acid fraction of bulk organic matter were dated at each station in order to test the ability of di¡erent organic fractions to return accurate 14 C ages, and to identify potential sources of contamination. Carbonized plant fragments are plant remains that have been partially reduced by geochemical and microbial activity in ground water (Cushing et al., 1986). They have not degraded completely into organic weathering products (i.e. ...
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During the middle Holocene (8–3 ka), wetland deposits accumulated in areas with emergent water tables in the central Atacama Desert (22–24°S), producing a stratigraphic unit (Unit C) that can be mapped and correlated across different basins and geomorphic settings. Wherever mapped, Unit C is located between 6 and 30 m above modern wetlands, and includes thick sequences of diatomite and organic mats. The origin, depositional environment, and paleoclimatic significance of Unit C is controversial and currently under debate. Grosjean [Science 292 (2001) 2391a] suggests the unit developed under a regime of falling lake and ground-water levels, whereas evidence presented here suggests that Unit C formed during a period of rising ground-water levels and increased vegetation cover. The debate is embedded in broader discussions about geomorphic processes in ground-water-fed streams, as well as the history and forcing of climate variability in the central Andes.
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We report the first mammoth tusk found (1985) on Santa Cruz Island, California. The tusk was secondarily deposited in alluvium of a former Pleistocene streambed. Wood in contact with the tusk radiocarbon dated at 10,290 ± 100 14 c yr B.P. (AA-1268). As this date obviously was equivocal relevant to the age of the tusk, we reviewed all dates published for mammoth fossils on the Northern Channel Islands. We conclude all of these dates also are equivocal. The reasons for this conclusion are discussed.
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Arlington Canyon, in the northwest part of Santa Rosa Island, Channel Islands National Park, California, has been the setting for important scientific discoveries over the past half century, including the oldest human remains in North America, several vertebrate fossil sites, and purported evidence of a catastrophic extinction event at the end of the Pleistocene. The canyon is filled with alluvial sediments that date to between 16.4 and 1.1 ka (thousands of calibrated years before present), representing accumulation that occurred primarily in response to rising sea levels during the late Pleistocene and Holocene. The deposits are laterally discontinuous, exhibit a high degree of sedimentary complexity, and contain evidence of past climates and environments, including fossil bones, burned plant macrofossils, and invertebrate microfossils. Here, we show that it is critical to view the observations, data, and conclusions of scientific studies conducted in the canyon within this larger context so that localized facets of the spatially and temporally extensive alluvial deposits are not misinterpreted or misrepresented. By improving the baseline understanding of processes and drivers of sediment accumulation in Arlington Canyon, we hope to offer a solid foundation and better underpinning for future archeological, paleontological, and geochemical studies here and throughout the northern Channel Islands.
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This paper is an attempt to place the dispute about early man in South America in historical context and to review the most convincing and important evidence that has been put forward. Essentially no skeletal remains- either in North or South America-have survived recent scrutiny and direct dating by accelerator mass spectrometry (AMS) and small CO2 counters. Only a handful of North American sites still are considered likely to be pre-Clovis, but the concept of an earlier, generalized hunting-and-gathering adaptation remains popular. In South America the pre-Paleoindian sites of the 1960s and 1970s are reevaluated and found to present only weak or negative indications of early occupation. Recently discovered sites in Brazil and Chile are examined critically, and the evidence is questioned. The results of this survey and evaluation suggest that we still lack the absolutely certain case that would be necessary to support the hypothesis of glacial-age occupation. Moreover, the probability of demonstration is seen to decrease, rather than increase, as the Paleoindian horizon increasingly is defined with more certainty while only equivocal cases are marshalled for an Archaic-like pre-Paleoindian stage. In summarizing prehistory, archaeologists should depend more on unambiguous and replicated cases, rather than on regional exceptions. More interpretive caution is needed, especially where there are possibilities of mixture and secondary deposition. Natural processes often mimic cultural patterns, confusing the positive identification of informal hearths and simple artifacts.
Chapter
Willard F Libby’s research, leading to the discovery of radiocarbon dating, was principally carried out at the University of Chicago after World War II with his main collaborators, E C Anderson and J R Arnold. At the behest of Libby, A V Grosse and his collaborators at the Houdry Process Corporation demonstrated the existence of radiocarbon in nature by concentrating the isotope from a source of biogenic methane. A Committee on Carbon-14 was formed from members of the American Anthropological Association and the Geological Society of America to select a significant slate of samples for dating. Committee members were Frederick Johnson, Donald Collier, Richard Foster Flint and Froelich Rainey, who all assisted Libby with advice and dating priorities. The basic technique for measuring radiocarbon was solid carbon dating, which Libby described in detail in his book entitled “Radiocarbon Dating” and two updated editions. Typically, samples were counted for 48 hours to accommodate the large numbers submitted. All radiocarbon dates obtained prior to the fall of 1951 by Libby’s original research team are listed in his publications (Libby 1952, 1955, 1965).
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Examen critique des donnees de 30 sites du Pleistocene inferieur et moyen d'Afrique, Asie et Europe, concernant l'utilisation du feu chez les premiers hominides. Les donnees anterieures aux neandertaliens sont equivoques. Discussion du role des processus naturels dans la production du feu. Presentation d'une methode d'evaluation des donnees
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California's Channel Islands have emerged as an important location for documenting the cultures and lifeways of the earliest peoples who settled the Pacific Coast of North America. Much of this began with Phil Orr's archaeological, paleontological, and geological research on Santa Rosa Island from the 1940s to 1960s. Generating several controversial theories, including the possibility of mammoth hunters on the islands over 40,000 years ago, many of Orr's interpretations have not stood the test of scientific scrutiny. However, much of what we know about the island today is based on Orr's extensive archaeological survey and excavation work. Here we provide an overview and analysis of Orr's research on the earliest peoples of Santa Rosa Island and update what has been learned in the 40 years since Orr's (1968) Prehistory of Santa Rosa Island was published. In 1968, Orr tentatively identified seven archaeological sites dating to the terminal Pleistocene and Early Holocene, all located on the northwest coast of Santa Rosa. Today, at least 18 sites are known to date within this same time range and their distribution has been expanded to other areas of the island. Current data show that Santa Rosa Island has one of the longest records of coastal occupation in the Americas, beginning at least 13,000 calendar years ago and extending into historic times.
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A soil chronosequence on marine terraces was examined on San Clemente Island, California, in an arid Mediterranean climate in order to see which soil properties differ most systematically with time. Ages of the geomorphic surfaces were determined by radiocarbon, uranium-series and amino acid racemization techniques and range from < 3,000 to >1,000,000 yrs.Soils on surfaces <200,000 yrs old are Alfisols or Mollisols which exhibit mainly prismatic structure in the B horizon. Soils > 200,000 yrs old are Vertisols or Alfisols with vertic properties such as slickensides and cracks and they exhibit both prismatic and angular blocky (sphenoidal) or only angular blocky structure. Solum thickness increases linearly with age of geomorphic surface. Clay, soluble salts, Ald, smectite/mica ratios in the clay fraction and quartz/plagioclase ratios in the silt fraction, when expressed as profile summations, show increases with age of geomorphic surface; the best-fit regression equations are linear with the exception of Ald which is best expressed as a power function. Important soilforming processes appear to be alteration of mica to smectite, accumulation at depth of soluble salts derived from marine aerosols, possibly additions of eolian materials, clay illuviation in the younger soils and pedoturbation in the older soils.The observations reported here allow the following conclusions to be drawn about soils in this environment: (1) certain soil properties which show distinct trends with time can be used for relative-age dating in geomorphic and stratigraphic studies; (2) soils have not reached a steady-state condition with respect to many of their properties; and (3) Alfisols and Mollisols with natric B horizons may be precursors to Vertisols.
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The following list contains samples of geologic interest that were processed from February 1974 through May 1980 at the Illinois State Geological Survey (ISGS) Radiocarbon Dating Laboratory. The archaeologic samples processed during the same period will be published in our next date list. The benzene liquid scintillation technique was used following laboratory procedures previously reported by Coleman (1973; 1974).
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Illuminates the changing character of the Late Quaternary environment of the California Borderland in general terms of its climate and vegetation, and in more specific terms of its faunal and human dispersals, migrations, and occupations.-from Author
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Artifacts excavated from alluvium are retrieved from the storage mode of the sediment budget. The sedmentary propertes of the alluvium, the form of the associated alluvial features, and the condition of recovered artifacts preserve evidence of conditions at the time sediment and artifacts entered storage. Secondary alteration indicates effects while these materials were in storage. Conventional techniques such as particle-size analysis, abrasion studies, and 14C dating can elaborate aspects of the storage condition if their respective limitations are considered. Geomorphological factors contributing to alluviation must be evaluated before the climatic forcing of palaeohydrological events can be assessed, and before palaeoenvironmental conditions can be inferred.-Author
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Samples of charcoal recovered from excavated sites were treated with strong acid, followed by strong base. This process removes most of the inorganic carbonates and organic compounds, leaving highly condensed or elementary carbon. The fixed carbon content of the specimens from four sites varied widely and indicated different sources of organic matter. Each charcoal, therefore, has a characteristic chemical composition.
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Features which have been interpreted as "fire hearths" and "charcoal" have been recorded in association with mammoth and other Pleistocene faunal remains. Some of these remains have been dated by the radiocarbon method as exceeding 10,000 years; a few are considerably in excess of this time. A review of some of these remains suggests the probability of noncultural origin for the carbonaceous material in question. Recent excavations in Merced and Orange counties, California, have revealed Pleistocene faunal remains in direct association with an abundance of carbonaceous material. It can be demonstrated that these remains are noncultural in origin.
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Flying across Africa to attend the Pan-African Congress on Prehistory in Livingstone in July of last year I was frequently reminded of how characteristic of man is his continual use of fire, not only in cities but in the primitive open spaces. There were few moments in the course of the whole journey when signs of fire or artificial light were not somewhere visible. As we passed over the sparsely inhabited bush and savannah country of south-central Africa one could sometimes count up to a dozen columns of smoke rising from the landscape spread out below. Some of these were deliberate bush-fires which the native farmers start early in the dry season as a safeguard against the disastrous spread of uncontrolled fire at the end of that season when the vegetation is like tinder. At the Livingstone Congress there were several communications bearing directly or indirectly on the question of how long has man, particularly in Africa, had fire at his disposal.
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The fire areas—or hearths—of the California Channel Islands, especially Santa Rosa Island, may be the oldest evidence of man in the Americas. The brick-red fire areas, dated at more than 40,000 years to 10,000 years ago, often contain charred mammoth bone and, rarely, possible stone tools. Though some of the fire areas may be hearths, recent research indicates that natural fires produce similar fire areas. Burned tree stumps and roots can redden the adjacent soil and resemble hearths. It is likely that most of the Pleistocene fire areas were caused by burned vegetation.
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Broken large mammal fossil bones in eastern Beringia have been used to argue for a middle-Wisconsin, or earlier, time of human entry into North America, It has been inferred that these controversial Pleistocene bones are artifacts because (1) they are similar to those found in archaeological sites and (2) they can be reproduced in the laboratory by replication. However, fractured, flaked, polished, faceted, cut, and scratched bones similar to the purportedly human artifacts described from Beringia are known to be produced by natural processes. New experimental data demonstrate that identifications of Pleistocene bone artifacts on the basis of differential staining and fresh breakage are suspect. Physical processes, such as the violent forces of river ice breakups in the north, and bone crushing by mammalian scavengers produce similar pseudo-artifacts. Additionally, the middle-Wisconsin dates associated with some of the finished tools, and human and dog bones from Beringia are open to question. The lack of credible dates on these artifacts raises doubt about the model of human colonization of Beringia, developed in the 1960s, which proposed an interstadial colonization of the New World.
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Burnt osteological materials are one focus of interest in forensic, archaeological, and palaeontological studies. We document the effects of experimental, controlled heating on a sample of modern bones and teeth from sheep and goats. Four aspects of heating specimens to between 20 and 940°C were considered: color, microscopic morphology, crystalline structure and shrinkage. Our results show that changes in both color and microscopic morphology of burnt bones and teeth can be divided into five stages each of which is typical of a particular temperature range, although the stages based on color do not correlate exactly with those based on micromorphology. These stages can be used to determine (1) if specimens of unknown taphonomic history were burnt, and (2) the maximum temperature reached by those specimens. In addition, powder X-ray diffraction studies show that heating causes an increase in the crystal size of hydroxyapatite, the major inorganic component of bones and teeth. This fact in conjunction with the microscopic morphology can be used to confirm deduced heating to 645°C or more. The data on shrinkage are analyzed to yield a polynomial expression that summarizes percentage shrinkage as a function of the maximum temperature reached by bones. Thus, the original size of specimens can be reconstructed within limits since the maximum temperature reached by the bones can be deduced on the basis of color, microscopic morphology and/or powder X-ray diffraction patterns. Finally, because there is a discrepancy between the maximum heating device temperature and the maximum specimen temperature, caution must be exercised in distinguishing between the effects of man made and natural fires.
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Mammoth remains on Santa Cruz Island, one of the four Northern Channel Islands of California, are very sparse, in marked contrast to those reported from Santa Rosa and San Miguel Islands of the same island group. A probable major reason for this scarcity is that Quaternary deposits are greatly restricted on Santa Cruz Island. It is proposed, contrary to popular opinion, that fossils found on Santa Cruz Island were derived from animals which died on the island, and were not transported there by humans. Reasons for this conclusion are that the size and geological context of the fossils are similar to those of the largest mammoth fossils of Santa Rosa Island, and that, in spite of extensive investigations by many persons, mammoth remains have not been found in middens, either on the islands or on the adjacent mainland.
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"May 1982." Thesis (Ph. D.)--Yale University, 1982. Includes bibliographical references (p. 263-277). Photocopy.
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Stable carbon isotope ratios of organic matter in rock varnishes of Holocene age from western North America and the Middle East show a strong association with the environment. This isotopic variability reflects the abundance of plants with different photosynthetic pathways in adjacent vegetation. Analyses of different layers of varnish on late Pleistocene desert landforms indicate that the carbon isotopic composition of varnish organic matter is a paleoenvironmental indicator.
The role of modern ecological studies in the reconstruction of paleoenvironments in sub-Saharan Africa
  • Coe
12th International Radiocarbon Conference
  • Gillespie
A late commentary on an early subject
  • MacNeish
Early man on Santa Rosa Island
  • Berger