Caborn-Welborn was a prehistoric North American culture defined by archaeologists as a Late Mississippian cultural manifestation that grew out of – or built upon the demise of – the Angel chiefdom located in the territory of southern present-day Indiana. Caborn-Welborn developed around 1400 and seems to have disappeared around 1700; the Caborn-Welborn culture was the last Native American occupation of southern Indiana before European contact. It remains unclear; the Caborn-Welborn culture is a cluster of more than 80 sites located on ridges along the Wabash and Ohio rivers from Geneva, Kentucky to the mouth of the Saline River. Most are concentrated near the confluence of the Wabash rivers; the sites range in size from 0.6 acres to 35 acres for the larger villages. Most sites are located on the higher flood plain ridges situated near sloughs and swamps; the Ohio River floodplain of this region has an extensive system of natural levees which parallel the river, with sloughs and swampy areas in between the levees.
Ashworth Archaeological Site – Located in Posey County and placed on the National Historic Register in 1985. Bone Bank Site – The site was a large village on the Wabash River in Posey County, it was nicknamed "Bone Bank" for the large number of remains of graves washed out of the site in the 19th century. It was established early in the Caborn-Welborn phase, about 1400. Hovey Lake-Klein Archeological Site – The site is located on the west bank of a backwater lake near the Ohio River, it was established about 1400. Murphy Archaeological Site – Located in Posey County and placed on the National Historic Register in 1975. Known as the Sullivan Farm Site and the Mouth-of-the-Wabash Site. Slack Farm Site – A large village near the mouth of the Wabash River in Union County, Kentucky. Welborn Village Archeological Site known as the Murphy's Landing Site – Located in Posey County. An internal temporal subdivision for the Caborn-Welborn culture, based on ceramic decorative attributes and the presence of European trade goods.
Pottery made by the Caborn-Welborn women was built up from strips of clay, smoothed out by the potter, much like other pottery in the Eastern America area, where the potters wheel was unknown. Common vessel shapes include jars, pans and funnels. Most jars tend to have rims with rounded necks and strap handles; the majority of the pottery found at Caborn-Welborn sites are of the kinds known as Mississippian Plain and Bell Plain, which are varieties common to most Mississippian cultures throughout the Ohio and Mississippi River valleys. It was buff colored, contains large fragments of ground mussel shell as a tempering agent, is not as smooth and polished as other varieties. Certain unique kinds of pottery and decorations define the Caborn-Welborn people as distinct from other cultures. Caborn-Welborn Decorated, Kimmswick Fabric Impressed, Kimmswick Plain are varieties which are present in greater frequencies in Caborn-Welborn sites, are hallmarks of the culture. Effigy jars, both of humans and animals, are common in Caborn-Welborn sites.
Some have a human or animal head and sometimes a tail attached to the rim, others are shaped into the forms of heads, with attached clay lugs to represent limbs. Caborn-Welborn Decorated, the most found decorated ceramic style, is characterized by incised or punctated lines on the shoulders of the jar forms. Other less common varieties found are indicative of continuity from preceding Lower Ohio Valley cultures and contact with the wider Mississippian world the Central Mississippi valley and the Oneota culture; these types include Old Town Red, O'Byam Incised/Engraved, Manly Punctate, Angel/Kincaid Negative Painted, Beckwith Incised, Barton Incised, Ranch Incised-Like, Parkin Punctate, Campbell Punctate, Walls Engraved, Vernon Paul Applique. The people of Caborn-Welborn were intensely involved in maize agriculture, as well as other food crops originating in the Americas, such as beans, squash and gourds; the addition of beans to their diet came after the demise of the Angel Phase peoples thought to have preceded the Caborn-Welborn.
It would have been a valuable source of protein to add to their maize-rich diet. Maize lacks the amino acids lysine and tryptophan, which the body needs to make proteins and niacin, but beans contain both, they collected local wild foodstuffs, including a variety of nuts such as hickory, black walnut and acorns, as well as fleshy fruits and berries such as persimmon and plums. The hunting of whitetail deer, squirrel, turkey and beaver added vital protein to their diet. But, unlike other Mississippian peoples in the central Mississippi Valley, they did not eat quantities of fish and waterfowl as part of their diet. By the final phase of Caborn-Welborn culture, European trade items began to be included among grave goods; these included copper and brass tubes, glass beads, bracelets. This is not indicative of direct European contact, however; the items could have made their way to the Caborn-Welborn area by the native traders along the routes which had brought exotic materials such as marine shells and native copper from other regions to the area for centuries.
But with the traders contracted and carried European diseases such as smallpox and measles, which penetrated the American continents far in advance of European-manned expeditions. With little or no immunity to the new European diseases, many Native cultures died or were disrupted before the Europeans made direct physical contact with them. The
Speleothems known as cave formations, are secondary mineral deposits formed in a cave. Speleothems form in limestone or dolostone solutional caves; the term "speleothem" as first introduced by Moore, is derived from the Greek words spēlaion "cave" + théma "deposit". The definition of "speleothem" in most publications excludes secondary mineral deposits in mines, tunnels and on man-made structures. Hill and Forti more concisely defined "secondary minerals". 319 variations of cave mineral deposits have been identified. The vast majority of speleothems are calcareous, composed of calcium carbonate in the form of calcite or aragonite, or calcium sulfate in the form of gypsum. Calcareous speleothems form via carbonate dissolution reactions. Rainwater in the soil zone reacts with soil CO2 to create weakly acidic water via the reaction: H2O + CO2 → H2CO3As the lower pH water travels through the calcium carbonate bedrock from the surface to the cave ceiling, it dissolves the bedrock via the reaction: CaCO3 + H2CO3 → Ca2+ + 2 HCO3−When the solution reaches a cave, degassing due to lower cave pCO2 drives precipitation of CaCO3: Ca2+ + 2 HCO3− → CaCO3 + H2O + CO2Over time the accumulation of these precipitates form stalagmites and flowstones, which compose the major categories of speleothems.
Calthemites which occur on concrete structures, are created by different chemistry to speleothems. Speleothems take various forms, depending on whether the water drips, condenses, flows, or ponds. Many speleothems are named for their resemblance to natural objects. Types of speleothems include: Dripstone is calcium carbonate in the form of stalactites or stalagmites Stalactites are pointed pendants hanging from the cave ceiling, from which they grow Soda straws are thin but long stalactites having an elongated cylindrical shape rather than the usual more conical shape of stalactites Helictites are stalactites that have a central canal with twig-like or spiral projections that appear to defy gravity Include forms known as ribbon helictites, rods, hands, curly-fries, "clumps of worms" Chandeliers are complex clusters of ceiling decorations Ribbon stalactites, or "ribbons", are shaped accordingly Stalagmites are the "ground-up" counterparts of stalactites blunt mounds Broomstick stalagmites are tall and spindly Totem pole stalagmites are tall and shaped like their namesakes Fried egg stalagmites are small wider than they are tall Columns result when stalactites and stalagmites meet or when stalactites reach the floor of the cave Flowstone is sheet like and found on cave floors and walls Draperies or curtains are thin, wavy sheets of calcite hanging downward Bacon is a drapery with variously colored bands within the sheet Rimstone dams, or gours, occur at stream ripples and form barriers that may contain water Stone waterfall formations simulate frozen cascades Cave crystals Dogtooth spar are large calcite crystals found near seasonal pools Frostwork is needle-like growths of calcite or aragonite Moonmilk is white and cheese-like Anthodites are flower-like clusters of aragonite crystals Cryogenic calcite crystals are loose grains of calcite found on the floors of caves, are formed by segregation of solutes during the freezing of water.
Speleogens are formations within caves that are created by the removal of bedrock, rather than as secondary deposits. These include: Pillars Scallops Boneyard Boxwork Others Cave popcorn known as "coralloids" or "cave coral", are small, knobby clusters of calcite Cave pearls are the result of water dripping from high above, causing small "seed" crystals to turn over so that they form into near-perfect spheres of calcium carbonate Snottites are colonies of predominantly sulfur oxidizing bacteria and have the consistency of "snot", or mucus Calcite rafts are thin accumulations of calcite that appear on the surface of cave poolsSpeleothems made of sulfates, mirabilite or opal occur in some lava tubes. Although sometimes similar in appearance to speleothems in caves formed by dissolution, lava stalactites are formed by the cooling of residual lava within the lava tube. Speleothems formed from salt and other minerals are known. Speleothems made of pure calcium carbonate are a translucent white color, but speleothems are colored by chemicals such as iron oxide, copper or manganese oxide, or may be brown because of mud and silt particulate inclusions.
Many factors impact the shape and color of speleothem formations including the rate and direction of water seepage, the amount of acid in the water, the temperature and humidity content of a cave, air currents, the above ground climate, the amount of annual rainfall and the density of the plant cover. Most cave chemistry revolves around calcium carbonate, the primary mineral in limestone and dolomite, it is a soluble mineral whose solubility increases with the introduction of carbon dioxide. It is paradoxical in that its solubility decreases as the temperature increases, unlike the vast majority of dissolved solids; this decrease is due to interactions with the carbon dioxide, whose solubility is diminished by elevated temperatures. Most other solution caves that are not composed of limestone or dolostone are composed of gypsum, the solubility of, positively c
Glacial Kame Culture
The Glacial Kame Culture was a culture of Archaic people in North America that occupied southern Ontario, Michigan and Indiana from around 8000 BC to 1000 BC. The name of this culture derives from its members' practice of burying their dead atop glacier-deposited gravel hills. Among the most common types of artifacts found at Glacial Kame sites are shells of marine animals and goods manufactured from a copper ore, knows as float copper; the type site for Glacial Kame is the Ridgeway Site near the village of Ridgeway in Hardin County, Ohio. The site was discovered in 1856 by workers building a railroad line nearby, who mined the kame for ballast. Archaeologists specializing in Ohio became familiar with Glacial Kame sooner than with the state's other cultures. Other regional cultures include the Maple Creek Culture of southwestern Ohio, Red Ocher Culture and Old Copper Culture of Wisconsin. For a time, it was thought that the Glacial Kame Culture did not produce ceramics, but this understanding was disproven by the discovery of basic pottery at the Zimmerman Site near Roundhead, Ohio.
Excavation of Glacial Kame sites yields few projectile points — some of the most important sites have yielded no projectile points at all — and their few points that have been found are of diverse styles. For this reason, it appears that different groups of Glacial Kame peoples independently developed different methods of manufacturing their projectile points; this diversity appears in the culture's heartland in Champaign and Logan counties in western Ohio. Keller, Christine K. Glacial Kame sandal-sole shell gorgets: an exploration of manufacture, use and public exhibition. 2008. Indian Culture History of Ohio
The Troyville culture is an archaeological culture in areas of Louisiana and Arkansas in the Lower Mississippi valley in the southern United States. It lasted from 400 to 700 CE during the Late Woodland period, it was contemporaneous with the Coastal Troyville and Baytown cultures and was succeeded by the Coles Creek culture. Where the Baytown peoples built dispersed settlements, the Troyville people instead continued building major earthwork centers; the Troyville-Coles Creek people lived on gathered wild plants and local domesticates, maize was of only minor importance. Acorns, palmetto and squash were all more important than maize. Tobacco was cultivated as well, protein came from deer and smaller mammals, but the bounty of the region kept maize from being adopted as a staple until as late as the thirteenth century CE. Culture and chronological table for the Mississippi Valley
In the sequence of cultural stages first proposed for the archaeology of the Americas by Gordon Willey and Philip Phillips in 1958, the Lithic stage was the earliest period of human occupation in the Americas, as post-glacial hunters and collectors spread through the Americas. The stage derived its name from the first appearance of Lithic flaked stone tools; the term Paleo-Indian is an alternative indicating much the same period. This stage was conceived of as embracing two major categories of stone technology: unspecialized and unformulated core and flake industries, with percussion the dominant and only technique employed, industries exhibiting more advanced "blade" techniques of stoneworking, with specialized fluted or unfluted lanceolate points the most characteristic artifact types. Throughout South America, there are stone tool traditions of the lithic stage, such as the "fluted fishtail" that reflect localized adaptations to the diverse habitats of the continent; the indications and timing of the end of the Lithic stage vary between regions.
The use of textiles, fired pottery and start of the gradual replacement of hunter gatherer lifestyles with the use of agriculture and domesticated animals would all be factors. End dates are around 5,000 to 3,000 BC in many areas; the Archaic stage is the most used term for the succeeding stage, but in the periodization of pre-Columbian Peru the Cotton Pre-Ceramic may be used, as in the Norte Chico civilization cultivated cotton seems to have been important in economic and power relations, from around 3,200 BC. One of the leading figures is Alex Krieger who has documented hundreds of sites that have yielded crude, percussion-flaked tools; the most convincing evidence for a lithic stage is based upon data recovered from sites in South America where such crude tools have been found and dated to more than 20,000 years ago. In North America, the time encompasses the Paleo-Indian period that subsequently is divided into more specific time terms such as Early Lithic stage or Early Paleo-Indians and Middle Paleo-Indians or Middle Lithic stage.
Examples include the Clovis culture and Folsom tradition groups. The Lithic stage was followed by the Archaic stage. 12,340 BCE–10,800 BCE: a stone-lined hearth and coprolites left in Paisley Caves, Oregon 10,200 BCE: Cooper Bison skull is painted with a red zigzag in present-day Oklahoma, becoming the oldest known painted object in North America. 9500 BC: Cordilleran and Laurentide ice sheets retreat enough to open a habitable ice-free corridor through Canada along the eastern flank of the Rocky Mountains. 9500 BC: People craft early Clovis spear points and skin scrapers from rock in New Mexico. 9250–8950 BC: Clovis points - thin, fluted projectile points created using bifacial percussion flaking - are created by Clovis culture peoples in the Plains and Southwestern North America 9001 BC: Archaeological materials found on the Channel Islands of California and in coastal Peru. 9000 BC: Archaeological materials found on Channel Islands off the California coast 9000 BC: Human settlers arrive in the Great Basin with its cool, wet prevailing climate 9000–8900 BC: The Folsom culture in New Mexico leaves Bison bones and stone spear points.
8700 BC: Human settlement reaches the Northwestern Plateau region. 8000 BC: The last glacial ends, causing sea levels to rise and flood the Beringia land bridge, closing the primary migration route from Siberia. 8000 BC: Sufficient rain falls on the American Southwest to support many large mammal species--mammoth, a bison species-—that soon go extinct. 8000 BC: Native Americans leave documented traces of their presence in every habitable corner of the Americas, including the American Northeast, the Pacific Northwest, a cave on Prince of Wales Island in the Alexander archipelago of southeast Alaska following these game animals. 8000 BC: Hunters in the American Southwest both use the atlatl. 8000 BC: Sufficient rain falls on the American Southwest to support many large mammal species, such as mammoth, a bison species-—that soon go extinct. 8000 BC: Hunters in the American Southwest use the atlatl. Times from the 8000 BC to about 3000 BC may be classified as part of the lithic stage or of an archaic stage, depending on authority and on region.
7500 BC: Early basketry. 7560—7370 BC: Kennewick Man dies along the shore of the Columbia River in Washington State, leaving one of the most complete early Native American skeletons. 7000 BC: Northeastern peoples depend on deer and wild grains as the climate warms. 7000 BC: Native Americans in Lahontan Basin, Nevada mummify their dead to give them honor and respect, evidencing deep concern about their treatment and condition. 6500 BC–200 AD: The San Dieguito-Pinto tradition and Chihuahua Tradition flourish in southern California, the Southwest, northwestern Mexico. 6000 BC: Ancestors of Penutian-speaking peoples settle in the Northwestern Plateau. 6000 BC: Nomadic hunting bands roam Subarctic Alaska following herds of caribou and other game animals. 6000 BC: Aleuts begin to arrive in the Aleutian Islands. 5700 BC: Cataclysmic eruption of Mount Mazama in Oregon. 5500 BC–500 AD Oshara Tradition, a Southwestern Archaic Tradition, arises in north-central New Mexico, the San Juan Basin, the Rio Grande Valley, southern Colorado, southeastern Utah.
Natives of the Northwestern Plateau begin to rely on salmon runs. 5000 BC: Early cultivation of food crops began in Mesoamerica. 5000 BC: Native Americans in the Pacific Northwest from Alaska to California develop a fishing economy, with salmon as a staple. 5000 BC: The Old Copper Culture of the Great Lakes area hammers the metal into various tools and ornaments, such as knives, awls, bracelets and pendants. Archaeology of the Amer
The Clovis culture is a prehistoric Paleo-Indian culture, named for distinct stone tools found in close association with Pleistocene fauna at Blackwater Locality No. 1 near Clovis, New Mexico, in the 1920s and 1930s. It appears around 11,500–11,000 uncalibrated radiocarbon years before present at the end of the last glacial period, is characterized by the manufacture of "Clovis points" and distinctive bone and ivory tools. Archaeologists' most precise determinations at present suggest this radiocarbon age is equal to 13,200 to 12,900 calendar years ago. Clovis people are considered to be the ancestors of most of the indigenous cultures of the Americas; the only human burial, directly associated with tools from the Clovis culture included the remains of an infant boy researchers named Anzick-1. Paleogenetic analyses of Anzick-1's ancient nuclear, Y-chromosome DNA reveal that Anzick-1 is related to modern Native American populations, which lends support to the Beringia hypothesis for the settlement of the Americas.
The Clovis culture was replaced by several more localized regional societies from the Younger Dryas cold-climate period onward. Post-Clovis cultures include the Folsom tradition, Suwannee-Simpson, Plainview-Goshen and Redstone; each of these is thought to derive directly from Clovis, in some cases differing only in the length of the fluting on their projectile points. Although this is held to be the result of normal cultural change through time, numerous other reasons have been suggested as driving forces to explain changes in the archaeological record, such as the Younger Dryas postglacial climate change which exhibited numerous faunal extinctions. After the discovery of several Clovis sites in eastern North America in the 1930s, the Clovis people came to be regarded as the first human inhabitants who created a widespread culture in the New World. However, this theory has been challenged, in the opinion of many archaeologists, by several archaeological discoveries, including sites such as Cactus Hill in Virginia, Paisley Caves in the Summer Lake Basin of Oregon, the Topper site in Allendale County, South Carolina, Meadowcroft Rockshelter in Pennsylvania, the Friedkin site in Texas, Cueva Fell in Chile, Monte Verde in Chile.
The oldest claimed human archaeological site in the Americas is the Pedra Furada hearths, a site in Brazil that precedes the Clovis culture and the other sites mentioned by 19,000 to 30,000 years. This claim has become an issue of contention between North American archaeologists and their South American and European counterparts, who disagree on whether it is conclusively proven to be an older human site. A hallmark of the toolkit associated with the Clovis culture is the distinctively shaped, fluted-stone spear point, known as the Clovis point; the Clovis point is bifacial and fluted on both sides. Archaeologists do not agree on whether the widespread presence of these artifacts indicates the proliferation of a single people, or the adoption of a superior technology by diverse population groups; the culture is named after artifacts found between 1936 at Blackwater Locality No. 1, an archaeological site between the towns of Clovis and Portales, New Mexico. These finds were deemed important due to their direct association with mammoth species and the extinct Bison antiquus.
The in situ finds of 1936 and 1937 included most of four stone Clovis points, two long bone points with impact damage, stone blades, a portion of a Clovis blade core, several cutting tools made on stone flakes. Clovis sites have since been identified throughout much of the contiguous United States, as well as Mexico and Central America, into northern South America. Clovis people are accepted to have hunted mammoths, as well as extinct bison, gomphotheres, tapir, camelops and other smaller animals. More than 125 species of plants and animals are known to have been used by Clovis people in the portion of the Western Hemisphere they inhabited; the oldest Clovis site in North America is believed to be El Fin del Mundo in northwestern Sonora, discovered during a 2007 survey. It features occupation dating around 13,390 calibrated years BP. In 2011, remains of gomphotheres were found; the Aubrey site in Denton County, produced an identical radiocarbon date. The most held perspective on the end of the Clovis culture is that a decline in the availability of megafauna, combined with an overall increase in a less mobile population, led to local differentiation of lithic and cultural traditions across the Americas.
After this time, Clovis-style fluted points were replaced by other fluted-point traditions with an uninterrupted sequence across North and Central America. An continuous cultural adaptation proceeds from the Clovis period through the ensuing Middle and Late Paleoindian periods. Whether the Clovis culture drove the mammoth, other species, to extinction via overhunting – the so-called Pleistocene overkill hypothesis – is still an open, controversial, question, it has been hypothesized that the Clovis culture had its decline in the wake of the Younger Dryas cold phase. This'cold shock', lasting 1500 years, affected many parts of the world, including North America; this appears to have been triggered by a vast amount of meltwater – from Lake Agassiz – emptying into the North Atlantic, disrupting the thermohaline circulation. The Younger Dryas impact hypothesis, or Clovis comet hypothesis proposed that a large air burst or earth impact of a comet or comets from outer space initiated the Younger Drya
The Hohokam were an ancient Native American culture centered in the present US state of Arizona. The Hohokam are one of the four major cultures of the American Southwest and northern Mexico in Southwestern archaeology. Considered part of the Oasisamerica tradition, the Hohokam established significant trading centers such as at Snaketown, are considered to be the builders of the original canal system around the Phoenix metropolitan area, which the Mormon pioneers rebuilt when they settled the Lehi area of Mesa near Red Mountain. Variant spellings in current, official usage include Hobokam and Huhukam; the Hohokam culture was differentiated from others in the region in the 1930s by archaeologist Harold S. Gladwin, who applied the existing O'odham term for the culture, huhu-kam, meaning "all used up" or "those who are gone", to classify the remains he was excavating in the Lower Gila Valley. According to the National Park Service Website, Hohokam is an O'odham word used by archaeologists to identify a group of people who lived in the Sonoran Desert.
According to local oral tradition, the Hohokam may be the ancestors of the historic Pima and Tohono O'odham peoples in Southern Arizona. Gila and lower Salt River drainages in what is known as the Phoenix basin; this is referred to as opposed to the Hohokam Peripheries. Collectively, the Core and Peripheries formed what is referred to as the Hohokam Regional System, which occupied the northern or Upper Sonoran Desert in what is now Arizona; the Hohokam extended into the Mogollon Rim region. Within a larger context, the Hohokam culture area inhabited a central trade position between the Patayan situated along the Lower Colorado River and in southern California. In North America, the Hohokam were the only culture to rely on irrigation canals to water their crops since as early as 800, their irrigation systems supported the largest population in the Southwest by 1300. Archaeologists working at a major archaeological dig in the 1990s in the Tucson Basin, along the Santa Cruz River, identified a culture and people that were ancestors of the Hohokam who might have occupied southern Arizona as early as 2000 BCE.
This prehistoric group from the Early Agricultural Period grew corn, lived year-round in sedentary villages, developed sophisticated irrigation canals. The Hohokam used the waters of the Salt and Gila Rivers and constructed an assortment of simple canals combined with weirs in their various agricultural pursuits. Since the 9th century and extending into the 15th century, they maintained what was to become extensive irrigation networks that rivaled the complexity of those used in the ancient Near East and China; these were constructed using simple excavation tools, without the benefit of advanced engineering technologies, achieved drops of a few feet per mile, balancing erosion and siltation. Over 70 years of archaeological research has revealed that the Hohokam cultivated varieties of cotton, maize and squash, as well as harvested a vast assortment of wild plants. Late in the Hohokam Chronological Sequence, they used extensive dry-farming systems to grow agave for food and fiber, their reliance on agricultural strategies based on canal irrigation, vital in their less than hospitable desert environment and arid climate, provided the basis for the aggregation of rural populations into stable urban centers.
Overall, Hohokam villages and smaller settlements can be classified within the ranchería-tradition. Many features of early Hohokam domestic architecture, such as large square or rectangular pithouses, seem to have been transplanted intact from early Formative Period examples first developed in the Tucson basin. But, by the seventh century, a distinct Hohokam architectural tradition emerged. Throughout the Hohokam Chronological Sequence, individual residential structures were excavated 40 cm below ground level, with plastered or compacted floors that covered between 12 and 35 m2, featured a circular, bowl-shaped, clay-lined hearth situated near the wall-entry. Hohokam burial practices varied over time; the primary method employed was flexed inhumation, similar to the tradition used by the southern Mogollon culture, located to the east. In the late Formative and Preclassic periods, the Hohokam cremated their dead, again strikingly similar to the traditions documented among the historic Patayan culture situated to the west along the Lower Colorado River.
Although the particulars of the practice changed somewhat, the Hohokam cremation tradition remained dominant until around 1300. At this time, extended inhumation, similar to that used by the Salado tradition to the north and northeast, was adopted. Many of the details of the late Hohokam burial patterns were similar to the tradition practiced by the historic Tohono and Akimel O'odham; as an archaeological construct, the Hohokam chronological sequence uses a culture history-based period/phase scheme designed to provide a narrative of what has been perceived as a sequence of significant cultural change. Overall, the reason the HCS is confusing is that two primary methods of expressing this information are used, within this context, a vast plethora of theoretical variants have been posited. Only the two