Paleontology or palaeontology is the scientific study of life that existed prior to, sometimes including, the start of the Holocene Epoch. It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments. Paleontological observations have been documented as far back as the 5th century BC; the science became established in the 18th century as a result of Georges Cuvier's work on comparative anatomy, developed in the 19th century. The term itself originates from Greek παλαιός, palaios, "old, ancient", ὄν, on, "being, creature" and λόγος, logos, "speech, study". Paleontology lies on the border between biology and geology, but differs from archaeology in that it excludes the study of anatomically modern humans, it now uses techniques drawn from a wide range of sciences, including biochemistry and engineering. Use of all these techniques has enabled paleontologists to discover much of the evolutionary history of life all the way back to when Earth became capable of supporting life, about 3.8 billion years ago.
As knowledge has increased, paleontology has developed specialised sub-divisions, some of which focus on different types of fossil organisms while others study ecology and environmental history, such as ancient climates. Body fossils and trace fossils are the principal types of evidence about ancient life, geochemical evidence has helped to decipher the evolution of life before there were organisms large enough to leave body fossils. Estimating the dates of these remains is essential but difficult: sometimes adjacent rock layers allow radiometric dating, which provides absolute dates that are accurate to within 0.5%, but more paleontologists have to rely on relative dating by solving the "jigsaw puzzles" of biostratigraphy. Classifying ancient organisms is difficult, as many do not fit well into the Linnaean taxonomy classifying living organisms, paleontologists more use cladistics to draw up evolutionary "family trees"; the final quarter of the 20th century saw the development of molecular phylogenetics, which investigates how organisms are related by measuring the similarity of the DNA in their genomes.
Molecular phylogenetics has been used to estimate the dates when species diverged, but there is controversy about the reliability of the molecular clock on which such estimates depend. The simplest definition of paleontology is "the study of ancient life"; the field seeks information about several aspects of past organisms: "their identity and origin, their environment and evolution, what they can tell us about the Earth's organic and inorganic past". Paleontology is one of the historical sciences, along with archaeology, astronomy, cosmology and history itself: it aims to describe phenomena of the past and reconstruct their causes. Hence it has three main elements: description of past phenomena; when trying to explain the past and other historical scientists construct a set of hypotheses about the causes and look for a smoking gun, a piece of evidence that accords with one hypothesis over the others. Sometimes the smoking gun is discovered by a fortunate accident during other research. For example, the discovery by Luis and Walter Alvarez of iridium, a extra-terrestrial metal, in the Cretaceous–Tertiary boundary layer made asteroid impact the most favored explanation for the Cretaceous–Paleogene extinction event, although the contribution of volcanism continues to be debated.
The other main type of science is experimental science, said to work by conducting experiments to disprove hypotheses about the workings and causes of natural phenomena. This approach cannot prove a hypothesis, since some experiment may disprove it, but the accumulation of failures to disprove is compelling evidence in favor. However, when confronted with unexpected phenomena, such as the first evidence for invisible radiation, experimental scientists use the same approach as historical scientists: construct a set of hypotheses about the causes and look for a "smoking gun". Paleontology lies between biology and geology since it focuses on the record of past life, but its main source of evidence is fossils in rocks. For historical reasons, paleontology is part of the geology department at many universities: in the 19th and early 20th centuries, geology departments found fossil evidence important for dating rocks, while biology departments showed little interest. Paleontology has some overlap with archaeology, which works with objects made by humans and with human remains, while paleontologists are interested in the characteristics and evolution of humans as a species.
When dealing with evidence about humans and paleontologists may work together – for example paleontologists might identify animal or plant fossils around an archaeological site, to discover what the people who lived there ate. In addition, paleontology borrows techniques from other sciences, including biology, ecology, chemistry and mathematics. For example, geochemical signatures from rocks may help to discover when life first arose on Earth, analyses of carbon isotope ratios may help to identify climate changes and to explain major transitions such as the Permian–Triassic extinction event. A recent discipline, molecular phylogenetics, compares the DNA and RNA of modern organisms to re-construct the "family trees" of their
Periodization is the process or study of categorizing the past into discrete, quantified named blocks of time. This is done in order to facilitate the study and analysis of history, understanding current and historical processes, causality that might have linked those events; this results in descriptive abstractions that provide convenient terms for periods of time with stable characteristics. However, determining the precise beginning and ending to any "period" is arbitrary, since it has changed over time over the course of history. To the extent that history is continuous and ungeneralizable, all systems of periodization are more or less arbitrary, yet without named periods, however clumsy or imprecise, past time would be nothing more than scattered events without a framework to help us understand them. Nations, cultures and individuals, each with their different remembered histories, are engaged in imposing overlapping unsystematized, schemes of temporal periodization; the division of history into "ages" or periods is old, recorded as early as the first development of writing.
The Sumerian King List operates with dynastic regnal eras. The classical division into a Golden Age, Silver Age, Bronze Age, Heroic Age and Iron Age goes back to Hesiod. One Biblical periodization scheme used in the Middle Ages was Saint Paul's theological division of history into three ages: the first before the age of Moses, but the most discussed periodization scheme of the Middle Ages was the Six Ages of the World, where every age was a thousand years counting from Adam to the present, with the present time being the sixth and final stage. Not only do periodizing blocks overlap, they seemingly conflict with or contradict one another; some have a cultural usage, others refer to prominent historical events, yet others are defined by decimal numbering systems. Other periods are named from talismanic individuals; some of these usages will be geographically specific. This is true of periodizing labels derived from individuals or ruling dynasties, such as the Jacksonian Era in America, the Meiji Era in Japan, or the Merovingian Period in France.
Cultural terms may have a limited reach. Thus the concept of the "Romantic period" is meaningless outside the Western world of Europe and European-influenced cultures. "the 1960s", though technically applicable to anywhere in the world according to Common Era numbering, has a certain set of specific cultural connotations in certain countries. For this reason it may be possible to say such things as "The 1960s never occurred in Spain"; this would mean that the sexual revolution, youth rebellion and so on never developed during that decade in Spain's conservative Roman Catholic culture and under Francisco Franco's authoritarian regime. It is often said, as the historian Arthur Marwick has, that "the 1960s" began in the late 1950s and ended in the early 1970s, his reason for saying this is that the cultural and economic conditions that define the meaning of the period covers more than the accidental fact of a 10-year block beginning with the number 6. This extended usage is termed the "long 1960s".
This usage derives from other historians who have adopted labels such as "the long 19th century" to reconcile arbitrary decimal chronology with meaningful cultural and social phases. An Eighteenth Century may run 1714–1789. Eric Hobsbawm has argued for what he calls "the short twentieth century", encompassing the period from the First World War through to the end of the Cold War. Similar problems attend other labels. Is it possible to use the term "Victorian" outside Britain, within, does her reign of 1837-1901 usefully constitute a historical period? It sometimes is used when it is thought that its connotations usefully describe the politics and economic conditions characteristic of the last two-thirds of the nineteenth century. Periodizing terms have negative or positive connotations that may affect their usage; this includes Victorian, which negatively suggests sexual repression and class conflict. Other labels such as Renaissance have positive characteristics; as a result, these terms sometimes extend in meaning.
Thus the English Renaissance is used for a period identical to the Elizabethan Period or reign of Elizabeth I, begins some 200 years than the Italian Renaissance. However the Carolingian Renaissance is said to have occurred during the reign of the Frankish king Charlemagne, his immediate successors. Other examples, neither of which constituted a "rebirth" in the sense of revival, are the American Renaissance of the 1820s-60s, referring to literature, the Harlem Renaissance of the 1920s, referring to literature but to music and the visual arts; the conception of a "rebirth" of Classical Latin learning is first credited to the Italian poet Petrarch, the father of Renaissance Humanism, but the conception of a rebirth has been in common use since Petrarch's time. The dominant usage of the word Renaissance refers to the cultural changes that occurred in Italy that culminated in the High Renaissance around 1500-1530; this concept applies dominantly to the visual arts, the work of Miche
West Sussex is a county in the south of England, bordering East Sussex to the east, Hampshire to the west and Surrey to the north, to the south the English Channel. West Sussex is the western part of the historic county of Sussex a medieval kingdom. With an area of 1,991 square kilometres and a population of over 800,000, West Sussex is a ceremonial county, with a Lord Lieutenant and a High Sheriff. Chichester in the south-west is the only city in West Sussex. West Sussex has a range of scenery, including wealden and coastal; the highest point of the county is at 280 metres. It has a number of stately homes including Goodwood, Petworth House and Uppark, castles such as Arundel Castle and Bramber Castle. Over half the county is protected countryside, offering walking and other recreational opportunities. Although the name Sussex, derived from the Old English'Sūþsēaxe', dates from the Saxon period between AD 477 to 1066, the history of human habitation in Sussex goes back to the Old Stone Age; the oldest hominin remains known in Britain were found at Boxgrove.
Sussex has been occupied since those times and has succumbed to various invasions and migrations throughout its long history. Prehistoric monuments include the Devil's Jumps, a group of Bronze Age burial mounds, the Iron Age Cissbury Ring and Chanctonbury Ring hill forts on the South Downs; the Roman period saw the building of Fishbourne Roman Palace and rural villas such as Bignor Roman Villa together with a network of roads including Stane Street, the Chichester to Silchester Way and the Sussex Greensand Way. The Romans used the Weald for iron production on an industrial scale; the foundation of the Kingdom of Sussex is recorded by the Anglo-Saxon Chronicle for the year AD 477. The foundation story is regarded as somewhat of a myth by most historians, although the archaeology suggests that Saxons did start to settle in the area in the late 5th century; the Kingdom of Sussex became the county of Sussex. With its origins in the kingdom of Sussex, the county of Sussex was traditionally divided into six units known as rapes.
By the 16th century, the three western rapes were grouped together informally, having their own separate Quarter Sessions. These were administered by a separate county council from 1888, the county of Sussex being divided for administrative purposes into the administrative counties of East and West Sussex. In 1974, West Sussex was made a single ceremonial county with the coming into force of the Local Government Act 1972. At the same time a large part of the eastern rape of Lewes was transferred into West Sussex; until 1834 provision for the poor and destitute in West Sussex was made at parish level. From 1835 until 1948 eleven Poor Law Unions, each catering for several parishes, took on the job. Most settlements in West Sussex are either along the south coast or in Mid Sussex, near the M23/A23 corridor; the town of Crawley is the largest in the county with an estimated population of 106,600. The coastal settlement of Worthing follows with a population of 104,600; the seaside resort of Bognor Regis and market town Horsham are both large towns.
Chichester, the county town, has a cathedral and city status, is situated not far from the border with Hampshire. Other conurbations of a similar size are Burgess Hill, East Grinstead and Haywards Heath in the Mid Sussex district, Littlehampton in the Arun district, Lancing and Shoreham in the Adur district. Much of the coastal town population is part of the Brighton/Worthing/Littlehampton conurbation. Rustington and Southwater are the next largest settlements in the county. There are several more towns in West Sussex; the smaller towns of the county are Arundel, Petworth and Steyning. The larger villages are Billingshurst, Crawley Down, Henfield, Hurstpierpoint, Lindfield and Storrington; the current total population of the county makes up 1.53% of England's population. West Sussex is bordered by Hampshire to Surrey to the north and East Sussex to the east; the English Channel lies to the south. The area has been formed from Upper Jurassic and Lower Cretaceous rock strata, part of the Weald–Artois Anticline.
The eastern part of this ridge, the Weald of Kent and Surrey has been eroded, with the chalk surface removed to expose older Lower Cretaceous rocks of the Wealden Group. In West Sussex the exposed rock becomes older towards the north of the county with Lower Greensand ridges along the border with Surrey including the highest point of the county at Blackdown. Erosion of softer sand and clay strata has hollowed out the basin of the Weald leaving a north facing scarp slope of the chalk which runs east and west across the whole county, broken only by the valleys of the River Arun and River Adur. In addition to these two rivers which drain most of the county a winterbourne, the River Lavant, flows intermittently from springs on the dip slope of the chalk downs north of Chichester; the county makes up 1.52% of the total land of England, making it the 30th largest county in the country. West Sussex is the sunniest county in the United Kingdom, according to Met Office records. Over the last 29 years it has averaged 1902 hours of sunshine per year.
Sunshine totals are highest near the coast wi
Archaeology, or archeology, is the study of human activity through the recovery and analysis of material culture. The archaeological record consists of artifacts, biofacts or ecofacts and cultural landscapes. Archaeology can be considered a branch of the humanities. In North America archaeology is a sub-field of anthropology, while in Europe it is viewed as either a discipline in its own right or a sub-field of other disciplines. Archaeologists study human prehistory and history, from the development of the first stone tools at Lomekwi in East Africa 3.3 million years ago up until recent decades. Archaeology is distinct from palaeontology, the study of fossil remains, it is important for learning about prehistoric societies, for whom there may be no written records to study. Prehistory includes over 99% of the human past, from the Paleolithic until the advent of literacy in societies across the world. Archaeology has various goals, which range from understanding culture history to reconstructing past lifeways to documenting and explaining changes in human societies through time.
The discipline involves surveying and analysis of data collected to learn more about the past. In broad scope, archaeology relies on cross-disciplinary research, it draws upon anthropology, art history, ethnology, geology, literary history, semiology, textual criticism, information sciences, statistics, paleography, paleontology and paleobotany. Archaeology developed out of antiquarianism in Europe during the 19th century, has since become a discipline practiced across the world. Archaeology has been used by nation-states to create particular visions of the past. Since its early development, various specific sub-disciplines of archaeology have developed, including maritime archaeology, feminist archaeology and archaeoastronomy, numerous different scientific techniques have been developed to aid archaeological investigation. Nonetheless, archaeologists face many problems, such as dealing with pseudoarchaeology, the looting of artifacts, a lack of public interest, opposition to the excavation of human remains.
The science of archaeology grew out of the older multi-disciplinary study known as antiquarianism. Antiquarians studied history with particular attention to ancient artifacts and manuscripts, as well as historical sites. Antiquarianism focused on the empirical evidence that existed for the understanding of the past, encapsulated in the motto of the 18th-century antiquary, Sir Richard Colt Hoare, "We speak from facts not theory". Tentative steps towards the systematization of archaeology as a science took place during the Enlightenment era in Europe in the 17th and 18th centuries. In Europe, philosophical interest in the remains of Greco-Roman civilization and the rediscovery of classical culture began in the late Middle Age. Flavio Biondo, an Italian Renaissance humanist historian, created a systematic guide to the ruins and topography of ancient Rome in the early 15th century, for which he has been called an early founder of archaeology. Antiquarians of the 16th century, including John Leland and William Camden, conducted surveys of the English countryside, drawing and interpreting the monuments that they encountered.
One of the first sites to undergo archaeological excavation was Stonehenge and other megalithic monuments in England. John Aubrey was a pioneer archaeologist who recorded numerous megalithic and other field monuments in southern England, he was ahead of his time in the analysis of his findings. He attempted to chart the chronological stylistic evolution of handwriting, medieval architecture and shield-shapes. Excavations were carried out by the Spanish military engineer Roque Joaquín de Alcubierre in the ancient towns of Pompeii and Herculaneum, both of, covered by ash during the Eruption of Mount Vesuvius in AD 79; these excavations began in 1748 in Pompeii, while in Herculaneum they began in 1738. The discovery of entire towns, complete with utensils and human shapes, as well the unearthing of frescos, had a big impact throughout Europe. However, prior to the development of modern techniques, excavations tended to be haphazard; the father of archaeological excavation was William Cunnington. He undertook excavations in Wiltshire from around 1798.
Cunnington made meticulous recordings of Neolithic and Bronze Age barrows, the terms he used to categorize and describe them are still used by archaeologists today. One of the major achievements of 19th-century archaeology was the development of stratigraphy; the idea of overlapping strata tracing back to successive periods was borrowed from the new geological and paleontological work of scholars like William Smith, James Hutton and Charles Lyell. The application of stratigraphy to archaeology first took place with the excavations of prehistorical and Bronze Age sites. In the third and fourth decades of the 19th-century, archaeologists like Jacques Boucher de Perthes and Christian Jürgensen Thomsen began to put the artifacts they had found in chronological order. A major figure in the development of archaeology into a rigorous science was the army officer and ethnologist, Augustus Pitt Rivers, who began excavations on his land in England in the 1880s, his approach was methodical by the standards of the time, he is regarded as the first scientific archaeologist.
He arranged his artifacts by type or "typologically, within types by date or "chronologically"
Christian Maclagan was a Scottish antiquarian and early archaeologist. She is known for her collection of rubbings of Celtic crosses and Pictish stones from across Scotland, was a pioneer of stratigraphic excavation. Although she lost the use of her right hand due to a medical condition she produced numerous drawings and paintings with her left hand, she took action to help those affected by poverty in Stirling. She refused to sit for portraits, she was a suffragist. She wrote an autobiography but the script remains lost, she was nominated to be one of Scotland's Heroines honoured at the National Wallace Monument's Hall of Heroes. She died in Stirling. Daughter of distiller and chemist George Maclagan and Janet Colville of Stirling, she was born on the family's farm at Braehead near Denny, her father died in 1818, as did her paternal grandfather, Frederick Maclagan, parish minister at Melrose, her mother moved the family to Stirling. She lived in a house in Pitt Terrace, a wealthy part of the town near St Ninian's Well and the modern Stirling Council offices.
Her mother died in 1858, until that time Christian Maclagan engaged in philanthropic activities, establishing a Sunday School and subscribing towards the cost of a library. After the Disruption of 1843 she joined the Free Church of Scotland and in 1865 she funded the building of a new kirk, her relationship with the Free Church soured in the 1870s and she sued to reclaim the church which she gifted to the established Church of Scotland. She received a bequest from one of her brothers at around the time of her mother's death, this established her as a woman of some wealth, her estate was valued at 3100 pounds sterling at her death. She was well-educated, knowing Latin, French and Gaelic well — her paternal grandfather had tried his hand at a translation of the Bible into Gaelic, she spoke some Italian and was an artist of some skill. Maclagan theorised that megalithic tombs were the remnants of houses and forts, she believed an academic examination of all such sites would reveal a message, through the archaeological'language' needed for such examination.
The findings of her investigations included rubbings from hundreds of archaeological specimens of various sites and were published at her own expense. She carried out an excavation on the Mither Tap of Bennachie; some of her theories were considered eccentric to her contemporaries. The dismissal of her views could be due to sexist attitudes of her era, or due to the anthropological comments Maclagan would make alongside her archaeological studies. At least one author criticized her work despite because of her Christian name, mistaking her for a man. One of her primary interests were in the brochs of Scotland and she was one of the pioneers of stratigraphic excavation, she devised a special method for taking rubbings from sculptured stones. Her greatest contribution to posterity was her meticulous collection of rubbings of Celtic Christian crosses and Pictish symbol stones, made from c 1850 onwards; these rubbings include some of the earliest done at Wemyss Cave. As a woman Maclagan was disbarred from obtaining a fellowship of the Society of Antiquaries of Scotland, instead she was a Lady Associate as were Lady John Scott and Queen Victoria.
She told friends. She threatened to resign the title since the society read her papers in her absence without her having the opportunity to respond, she could not formally publish with the Society and required a man to publish her work under his name. As a result of this, it has been supposed, she sent her rubbings to the British Museum, she remained a Lady Associate however until the time of her death around the age of 92. The Smith Museum in Stirling contains one of her models of a broch tower and a wooden carving as a tribute to her, she was buried in Stirling's old town cemetery. This sexism may have led to her work being overlooked and one of her key discoveries Livilands Broch being lost. A crowdfunding project was launched in 2016 by Stirling Council's Archaeologist Dr Murray Cook to rediscover the broch that she discovered; the Hill Forts Stone Circles and Others Structural Remains of Ancient Scotland and Douglas, 1875. Chips from old stones 1881 What Mean These Stones? D. Douglas, 1894. A catalogue raisonné of the British Museum collection of rubbings from ancient sculptured stones.
1898 On the Round Castles and Ancient Dwellings of the Valley of the Forth, its Tributary the Teith. Notes of a Roman Sculptured Stone discovered at Cumbernauld, of an Inscribed Stone at Stirling, &c
In earth science, erosion is the action of surface processes that removes soil, rock, or dissolved material from one location on the Earth's crust, transports it to another location. This natural process is caused by the dynamic activity of erosive agents, that is, ice, air, plants and humans. In accordance with these agents, erosion is sometimes divided into water erosion, glacial erosion, snow erosion, wind erosion, zoogenic erosion, anthropogenic erosion; the particulate breakdown of rock or soil into clastic sediment is referred to as physical or mechanical erosion. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres. Natural rates of erosion are controlled by the action of geological weathering geomorphic drivers, such as rainfall; the rates at which such processes act control. Physical erosion proceeds fastest on steeply sloping surfaces, rates may be sensitive to some climatically-controlled properties including amounts of water supplied, wind speed, wave fetch, or atmospheric temperature.
Feedbacks are possible between rates of erosion and the amount of eroded material, carried by, for example, a river or glacier. Processes of erosion that produce sediment or solutes from a place contrast with those of deposition, which control the arrival and emplacement of material at a new location. While erosion is a natural process, human activities have increased by 10-40 times the rate at which erosion is occurring globally. At well-known agriculture sites such as the Appalachian Mountains, intensive farming practices have caused erosion up to 100x the speed of the natural rate of erosion in the region. Excessive erosion causes both "on-site" and "off-site" problems. On-site impacts include decreases in agricultural productivity and ecological collapse, both because of loss of the nutrient-rich upper soil layers. In some cases, the eventual end result is desertification. Off-site effects include sedimentation of waterways and eutrophication of water bodies, as well as sediment-related damage to roads and houses.
Water and wind erosion are the two primary causes of land degradation. Intensive agriculture, roads, anthropogenic climate change and urban sprawl are amongst the most significant human activities in regard to their effect on stimulating erosion. However, there are many prevention and remediation practices that can curtail or limit erosion of vulnerable soils. Rainfall, the surface runoff which may result from rainfall, produces four main types of soil erosion: splash erosion, sheet erosion, rill erosion, gully erosion. Splash erosion is seen as the first and least severe stage in the soil erosion process, followed by sheet erosion rill erosion and gully erosion. In splash erosion, the impact of a falling raindrop creates a small crater in the soil, ejecting soil particles; the distance these soil particles travel can be as much as 0.6 m vertically and 1.5 m horizontally on level ground. If the soil is saturated, or if the rainfall rate is greater than the rate at which water can infiltrate into the soil, surface runoff occurs.
If the runoff has sufficient flow energy, it will transport loosened soil particles down the slope. Sheet erosion is the transport of loosened soil particles by overland flow. Rill erosion refers to the development of small, ephemeral concentrated flow paths which function as both sediment source and sediment delivery systems for erosion on hillslopes. Where water erosion rates on disturbed upland areas are greatest, rills are active. Flow depths in rills are of the order of a few centimetres or less and along-channel slopes may be quite steep; this means that rills exhibit hydraulic physics different from water flowing through the deeper, wider channels of streams and rivers. Gully erosion occurs when runoff water accumulates and flows in narrow channels during or after heavy rains or melting snow, removing soil to a considerable depth. Valley or stream erosion occurs with continued water flow along a linear feature; the erosion is both downward, deepening the valley, headward, extending the valley into the hillside, creating head cuts and steep banks.
In the earliest stage of stream erosion, the erosive activity is dominantly vertical, the valleys have a typical V cross-section and the stream gradient is steep. When some base level is reached, the erosive activity switches to lateral erosion, which widens the valley floor and creates a narrow floodplain; the stream gradient becomes nearly flat, lateral deposition of sediments becomes important as the stream meanders across the valley floor. In all stages of stream erosion, by far the most erosion occurs during times of flood when more and faster-moving water is available to carry a larger sediment load. In such processes, it is not the water alone
Single context recording
Single context recording was developed by Ed Harris and Patrick Ottaway in 1976, from a suggestion by Lawrence Keene. It was further developed by the Department of Urban Archaeology from where it was exported, in the mid-1980s by Pete Clarke to the Scottish Urban Archaeological Trust and Nick Pearson to the York Archaeological Trust, it has become a popular system of recording and planning being used in many countries in Europe and in Lebanon, it is suited to the complexities of deep urban, archaeology. Each excavated context is given a unique "context number" and is recorded by type on a context sheet and being drawn on a plan and/or a section. Depending on time constraints and importance contexts may be photographed, but in this case a grouping of contexts and their associations are the purpose of the photography. Finds from each context are bagged and labelled with their context number and site code for cross reference work carried out post excavation; the height above sea level of pertinent points on a context, such as the top and bottom of a wall are taken and added to plans sections and context sheets.
Heights are recorded with a dumpy level or total station by relation to the site temporary benchmark. Samples of deposits from contexts are sometimes taken, for environmental analysis or for scientific dating. Contexts being excavated are recorded on context sheets which vary in style depending on practitioner but in general share characteristics. Most will have sections for composition of profiles for cuts, it is common practice to have special sheets available to record contexts denoted by. A plan is made that conforms to grid squares. Single context recording of a stratigraphically excavated sequence evolves into an overlay of planned contexts that build a Harris matrix during excavation; this is demonstrated in the gallery below of a hypothetical and abstract 5 step sequence of contexts. The excavation starts with the planning and removal of a deposit in step 1 and continues down through a sequence of 4 cut features. Note how only the stratigraphic relationships build into the matrix as the excavation progresses rather than all the physical relationships.
In reality the process is more complex and involves many more contexts for the series of features shown in the diagram. This is because the contexts representing the fills have been omitted for simplicity and the matrix shown is more akin to a Carver matrix. Critics of single context recording point out that it encourages a lazy attitude towards attempts to phase the site while excavation is in progress, that it diminishes the incentive for archaeologists to interpret what they are digging beyond the boundaries of the context being excavated rather than trying to understand it using the entire area of the site for insight, it is argued that this lack of interpretation leads to a thoughtless use of the law of superposition, creating chronological anomalies from features and contexts of a tunnelling nature such as drain backfills, buried waterfront tiebacks or natural processes. Counter-critics argue that, while this is a possibility, no archaeologist needs to be transfixed by the applied recording system if faced with a stratigraphic conundrum, that deviation from a pure single context recording regime is not a sin.
Furthermore, single context recording is not an excuse for not attempting to view the site as a whole during excavation. Archaeological association Archaeological context Archaeological plan Archaeological section Cut Excavation Feature Relationship The MoLAS archaeological site manual MoLAS, London 1994. ISBN 0-904818-40-3. Rb 128pp. Bl/wh Adrian Chadwick - Archaeology at the Edge of Chaos: Further Towards Reflexive Excavation Methodologies