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41-902: The Calico Early Man Site is an archaeological site in an ancient Pleistocene lake located near Barstow in San Bernardino County in the central Mojave Desert of Southern California . This site is on and in late middle- Pleistocene fanglomerates (now-cemented alluvial debris flow deposits) known variously as the Calico Hills, the Yermo Hills, or the Yermo formation. Holocene evidence includes petroglyphs and trail segments that are probably related to outcrops of local high-quality siliceous rock (primarily chalcedony in freshwater limestone ). The Calico Early Man Site includes: The tools and flakes of LMLI and those found in

82-494: A Geographical Information Systems (GIS) and that will contain both locational information and a combination of various information. This tool is very helpful to archaeologists who want to explore in a different area and want to see if anyone else has done research. They can use this tool to see what has already been discovered. With this information available, archaeologists can expand their research and add more to what has already been found. Traditionally, sites are distinguished by

123-683: A sequence of natural geological or organic deposition, in the absence of human activity, to constitute a site worthy of study. Archaeological sites usually form through human-related processes but can be subject to natural, post-depositional factors. Cultural remnants which have been buried by sediments are, in many environments, more likely to be preserved than exposed cultural remnants. Natural actions resulting in sediment being deposited include alluvial (water-related) or aeolian (wind-related) natural processes. In jungles and other areas of lush plant growth, decomposed vegetative sediment can result in layers of soil deposited over remains. Colluviation ,

164-537: A series of deposits that represent more than 350,000 years of Quaternary history. The Manix Basin, a structural basin in the central Mojave Desert , is the third and lowest major valley of the Mojave River , presently an exotic stream with episodic flow, which has its source in the San Bernardino Mountains , some 200 km (120 mi) to the southeast. A freshwater lake developed in

205-444: A shred of evidence." The geologist Vance Haynes had made three visits to the site in 1973 and had claimed that the artifacts of Leakey were naturally formed geofacts . According to Haynes, the geofacts were formed by stones becoming fractured in an ancient river on the site. In her autobiography, Louis' wife Mary Leakey wrote that because of his involvement with the Calico Hills site she had lost academic respect for him, and that

246-412: A site as well. Development-led archaeology undertaken as cultural resources management has the disadvantage (or the benefit) of having its sites defined by the limits of the intended development. Even in this case, however, in describing and interpreting the site, the archaeologist will have to look outside the boundaries of the building site. According to Jess Beck in "How Do Archaeologists Find Sites?"

287-453: A site worthy of study. Different archaeologists may see an ancient town, and its nearby cemetery as being two different sites, or as being part of the same wider site. The precepts of landscape archaeology attempt to see each discrete unit of human activity in the context of the wider environment, further distorting the concept of the site as a demarcated area. Furthermore, geoarchaeologists or environmental archaeologists would also consider

328-484: A strong resemblance to prehistoric tools have been found at the site, both on the surface, and up to 8 m (26 ft) below the surface. A stone from the Master Pit had been dated to over 200,000 BP . This date could have been the result of contamination from other elements in the soil, so currently there is an effort to date verified lithics through thermoluminescence dating. While the results are still pending,

369-515: A visit from Ruth DeEtte Simpson , an archaeologist from California. Simpson had acquired what looked like ancient scrapers from a site in the Calico Hills and showed it to Leakey. Leakey viewed it as important to study the Calico Hills site, as he was convinced that the number and distribution of native languages in the Americas required more time than 12,000 years to evolve and acquire their current distribution. In 1963, Leakey obtained funds from

410-500: Is a branch of survey becoming more and more popular in archaeology, because it uses different types of instruments to investigate features below the ground surface. It is not as reliable because although they can see what is under the surface of the ground, it does not produce the best picture. Archaeologists still have to dig up the area in order to uncover the truth. There are also two most common types of geophysical survey, which is, magnetometer and ground penetrating radar. Magnetometry

451-551: Is no significant difference between the sample of alleged tools and the uncontrolled fracture series.” (Payen 1982:200). Duvall and Venner (1979:462) examined a sample of Calico artifacts and concluded they were form-selected examples of naturally flaked rocks. Their assessment was based on variances in seven attributes (length, width, thickness, flake angle, medial axis angle, lateral edge angle, and distal edge angle) and comparison with comparable attributes on specimens in eight Paleoindian collections reported by Wilmsen (1970). Both

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492-629: Is the technique of measuring and mapping patterns of magnetism in the soil. It uses an instrument called a magnetometer, which is required to measure and map traces of soil magnetism. The ground penetrating radar is a method that uses radar pulses to image the subsurface. It uses electromagnetic radiation in the microwave band of the radio spectrum and detects the reflected signals from subsurface structures. There are many other tools that can be used to find artifacts, but along with finding artifacts, archaeologists have to make maps. They do so by taking data from surveys, or archival research and plugging it into

533-593: The National Geographic Society and commenced archaeological excavations with Simpson. Excavations in an area stratigraphically separate from a verified 10,000-year-old Paleoindian site were carried out by Leakey and Simpson, who believed that they had located stone artifacts that were dated 100,000 years or older, suggesting a human presence in North America much earlier than estimated. The archaeologist Jeffrey Goodman who worked at

574-664: The University of Copenhagen instead uses the unambiguous "b2k", for "years before 2000 AD", often in combination with the Greenland Ice Core Chronology 2005 (GICC05) time scale. Some authors who use the YBP dating format also use "YAP" ("years after present") to denote years after 1950. SI prefix multipliers may be used to express larger periods of time, e.g. ka BP (thousand years BP), Ma BP (million years BP) and many others . Radiocarbon dating

615-460: The Calico excavations was "catastrophic to his professional career and was largely responsible for the parting of our ways". She did not share his visionary views about the Calico site. She regarded Louis as often slipping into incompetence and often publicized that opinion. Louis Leakey continued to visit the site several times a year and was connected with the project until his death in 1972. The site

656-712: The Duvall/Venner and the Payen papers have been criticized on a number of levels, and analyses supporting the pro-artifact argument have been published. The present consensus is that there is no evidence of human activity at the Calico Early Man site. This consensus developed based on a number of factors, including: In 1959 Louis Leakey , while at the British Museum of Natural History in London , received

697-474: The Manix Basin (Lower Mojave Valley) of San Bernardino County, California a fortuitous ensemble of environmental factors relating to mountain building, climatically controlled conditions for lake formation, alluviation, and erosion , faulting and folding and significant erosion of ancient lacustrine plain sediments by the modern drainage have rendered relatively accessible for archaeological investigation

738-680: The Manix fault. The lacustrine, fluvial, and alluvial sediments of the Pleistocene Manix Formation contain remains of numerous Rancholabrean animals ranging in age from approximately 20,000 years to well in excess of 350,000 years before present. Fossils recovered from the section include: camel, horse, mammoth, saber-tooth cat, dire wolf, short-faced bear, coyote, flamingo, pelican, eagle, swan, geese, mallard duck, ruddy duck, canvas backed duck, double-crested cormorant, grebe, crane, seagull and stork. Thousands of rocks that bear

779-806: The Yermo Hills) east of the Calico Peaks and the Calico Mountains . The location is in the central portion of southern California's Mojave Desert . Historically, this archaeological project has also been known as "The Calico Mountains Archaeological Site" and "The Calico Hills Archaeological Site". Today, it is called "The Calico Early Man Site". In most of the Great Basin region, Late Pleistocene and Holocene alluviation has effectively buried and sealed earlier Pleistocene sediments and possible evidence of pre- Clovis cultures . In

820-437: The alluvial deposits at Calico and produced specimens indistinguishable from artifacts. Specimens collected from earlier excavations up to the present are under analysis by archaeologists volunteering at the Calico site. Many have been confirmed to be geofacts, but some are believed to be potential artifacts and have been cataloged and submitted for thermoluminescent dating. Currently work is being done on compiling and publishing

861-596: The angles scar-platform are obtuse (90° and over)” (Barnes 1939:111). Payen measured all flake angles on each Calico specimen in his sample. It is conceivable that flake scars were confused for striking platforms. Flaking from one side of a specimen can often remove earlier platform areas on the other side. Angles between two flake scars are different from angles between platforms and derivative flake scars. Payen compared mean angle values for Calico specimens with those on specimens selected as representing controlled and uncontrolled fracture. He found that “Statistically, there

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902-583: The area, and if they have the money and time for the site, they can start digging. There are many ways to find sites, one example can be through surveys. Surveys involve walking around analyzing the land and looking for artifacts. It can also involve digging, according to the Archaeological Institute of America, "archaeologists actively search areas that were likely to support human populations, or in places where old documents and records indicate people once lived." This helps archaeologists in

943-573: The areas with numerous artifacts are good targets for future excavation, while areas with a small number of artifacts are thought to reflect a lack of past human activity. Many areas have been discovered by accident. The most common people who have found artifacts are farmers who are plowing their fields or just cleaning them up, and they often find archaeological artifacts. Many people who are out hiking and even pilots find artifacts, and they usually end up reporting them to archaeologists for further investigation. When they find sites, they have to first record

984-515: The basin about 400,000 – 500,000 years ago near the Calico Archaeological Site. The lake was present until the late Pleistocene . The last high stand of Lake Manix was at 543 m (1,781 ft) and had a surface area of approximately 236 km (91 sq mi). This lake drained, probably catastrophically, approximately 18,100 years ago, probably as a result of a major increase in river inflow or tectonic movement on

1025-428: The burial of a site by sediments moved by gravity (called hillwash ) can also happen at sites on slopes. Human activities (both deliberate and incidental) also often bury sites. It is common in many cultures for newer structures to be built atop the remains of older ones. Urban archaeology has developed especially to deal with these sorts of site. Many sites are the subject of ongoing excavation or investigation. Note

1066-428: The definition and geographical extent of a "site" can vary widely, depending on the period studied and the theoretical approach of the archaeologist. It is almost invariably difficult to delimit a site. It is sometimes taken to indicate a settlement of some sort, although the archaeologist must also define the limits of human activity around the settlement. Any episode of deposition, such as a hoard or burial, can form

1107-476: The difference between archaeological sites and archaeological discoveries. Years before present In a convention that is not always observed, many sources restrict the use of BP dates to those produced with radiocarbon dating; the alternative notation "RCYBP" stands for the explicit "radio carbon years before present". The BP scale is sometimes used for dates established by means other than radiocarbon dating, such as stratigraphy . This usage differs from

1148-476: The exponential decay relation and the "Libby half-life" 5568 a. The ages are expressed in years before present (BP) where "present" is defined as AD 1950. The year 1950 was chosen because it was the standard astronomical epoch at that time. It also marked the publication of the first radiocarbon dates in December 1949, and 1950 also antedates large-scale atmospheric testing of nuclear weapons , which altered

1189-420: The future. In case there is no time or money during the site's discovery, archaeologists can come back and visit the site for further digging to find out the extent of the site. Archaeologist can also sample randomly within a given area of land as another form of conducting surveys. Surveys are very useful, according to Jess Beck, "it can tell you where people were living at different points in the past." Geophysics

1230-480: The global ratio of carbon-14 to carbon-12 . Dates determined using radiocarbon dating come as two kinds: uncalibrated (also called Libby or raw ) and calibrated (also called Cambridge ) dates. Uncalibrated radiocarbon dates should be clearly noted as such by "uncalibrated years BP", because they are not identical to calendar dates. This has to do with the fact that the level of atmospheric radiocarbon ( carbon-14 or C) has not been strictly constant during

1271-552: The most recent finds at the site to be submitted to the local tribes, community and journals for peer review. Payen (1982) studied flake scar angles as traits for distinguishing artifacts from geofacts. He tested a method developed by Barnes (1939) who had compared frequency of obtuse angles on eoliths, natural fractures, and artifacts. Barnes found obtuse angles on 72% of eoliths, 75% of natural fractures, and 18% of artifacts and concluded that “The flaked tools of an industry…may be considered to be of human origin if not more than 25% of

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1312-516: The name (standard codes are used) of the laboratory concerned, and other information such as confidence levels, because of differences between the methods used by different laboratories and changes in calibrating methods. Conversion from Gregorian calendar years to Before Present years is by starting with the 1950-01-01 epoch of the Gregorian calendar and increasing the BP year count with each year into

1353-468: The nested inset known as the Rock Wren Locality were probably made by modern man ( Homo sapiens sapiens ). The stone tools of these industries, along with preforms , lithic core , technical flakes , and pieces of angular debitage , mainly of chalcedony , are found on and in late middle Pleistocene-age fanglomerates and younger inset alluvial terraces in the Calico Hills (also known as

1394-471: The presence of both artifacts and features . Common features include the remains of hearths and houses. Ecofacts , biological materials (such as bones, scales, and even feces) that are the result of human activity but are not deliberately modified, are also common at many archaeological sites. In the cases of the Palaeolithic and Mesolithic eras, a mere scatter of flint flakes will also constitute

1435-496: The recommendation by van der Plicht & Hogg, followed by the Quaternary Science Reviews , both of which requested that publications should use the unit "a" (for "annum", Latin for "year") and reserve the term "BP" for radiocarbon estimations. Some archaeologists use the lowercase letters bp , bc and ad as terminology for uncalibrated dates for these eras. The Centre for Ice and Climate at

1476-450: The site with Leakey had also claimed the stone artifacts to be human made. Goodman has also made controversial statements that the artifacts found at Calico Hills may be as old as 500,000 years and if proven would be the oldest human artifacts in the world, which would place human origins in the Americas. However, the majority of scientists have rejected these claims. According to Kenneth Feder , "Goodman's claims were not backed up with even

1517-596: The span of time that can be radiocarbon-dated. Uncalibrated radiocarbon ages can be converted to calendar dates by calibration curves based on comparison of raw radiocarbon dates of samples independently dated by other methods, such as dendrochronology (dating based on tree growth-rings) and stratigraphy (dating based on sediment layers in mud or sedimentary rock). Such calibrated dates are expressed as cal BP, where "cal" indicates "calibrated years", or "calendar years", before 1950. Many scholarly and scientific journals require that published calibrated results be accompanied by

1558-740: The styles suggest 20,000 to 30,000 BP. The debate centers on whether the "tools" were made by humans (i.e., artifacts ), or through typical geological processes (i.e. geofacts ). The general scientific consensus is that the subsurface items are geofacts. The artifactual character of the Calico lithic assemblage has been questioned (Haynes 1973; Payen 1982a, 1982b; Taylor and Payen 1979; Duvall and Venner 1979). Haynes (1973) postulated that rock fracturing by tectonic stresses, weather, rock-on-rock percussion in streams and mudflows, pressure retouch of buried cobbles, and successive generations of flake removal and separation from cores through cycles of erosion and redeposition could have occurred during deposition of

1599-446: Was first used in 1949. Beginning in 1954, metrologists established 1950 as the origin year for the BP scale for use with radiocarbon dating, using a 1950-based reference sample of oxalic acid . According to scientist A. Currie Lloyd: The problem was tackled by the international radiocarbon community in the late 1950s, in cooperation with the U.S. National Bureau of Standards . A large quantity of contemporary oxalic acid dihydrate

1640-525: Was prepared as NBS Standard Reference Material (SRM) 4990B. Its C concentration was about 5% above what was believed to be the natural level, so the standard for radiocarbon dating was defined as 0.95 times the C concentration of this material, adjusted to a C reference value of −19 per mil (PDB). This value is defined as "modern carbon" referenced to AD 1950. Radiocarbon measurements are compared to this modern carbon value, and expressed as "fraction of modern" (fM). "Radiocarbon ages" are calculated from fM using

1681-601: Was taken over by the Bureau of Land Management and was opened to the public. Archaeological site An archaeological site is a place (or group of physical sites) in which evidence of past activity is preserved (either prehistoric or historic or contemporary), and which has been, or may be, investigated using the discipline of archaeology and represents a part of the archaeological record . Sites may range from those with few or no remains visible above ground, to buildings and other structures still in use. Beyond this,

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