Theme 1 - Science or Not? Flashcards
what do artifacts provide us?
Artifacts can provide information on many aspects of past life ways including economic practices and procurement of raw materials, social relationships and even the evolution of cognition.
what happens when artifacts enter a new micro-environment?
Post-deposition, artifacts that enter a a new micro-environment undergo modification and general material breakdown: physical, chemical or biological
what impacts the extent of modification?
the extent to which the artifact is modified depends on the reaction of the raw material to the new environment such as chemical (soil acids), Biological (insect, fungal or bacterial attack), mechanical (plough, furrows)
what happens to artifacts made from inorganic materials?
Artifacts made from inorganic materials generally undergo the least modification hence, best preserved and most abundant finds, although, metal is an exception of this
what happens to artifacts made from organic materials?
Artifacts made from organic materials are only preserved under exceptional conditions when the action of bacteria, fungi or insects are inhibited such as extreme cold, arid or waterlogged.
what conditions are the best for artifact preservation?
among the worlds best preserved organic artefacts are those preserved under cold conditions via permafrost that can preserve remains of wood, fur, leather and textiles.
what is usually preserved on human remains, what is unusual?
on most archaeological sites only hard tissue (i.e. skeleton) of human remains are preserved however, with ‘bog bodies’ there is a preservation of the soft tissue.
how does the artifact change once unearthed?
a buried artifact eventually reaches equilibrium with its environment, once unearthed it adjusts to its new materials micro-environment
what happens to organic materials? how can this be helped?
Organic materials start to deteriorate therefore must be conserved in the field. Fragile artefacts may need to be conserved before removal: bones may be covered in plaster or timber coated in PVA
what does general rule of thumb state?
General rule of thumb states that artefacts should be kept under the conditions in which they were found. For example wood from waterlogged sites must be kept wet, treated with fungicide and chemically impregnated to prevent shrinkage when drying in the lab.
what must field treatments be?
any field treatment of artefacts must be reversible, adhesives and consolidants must be removable as a conservator may decide a different treatment is necessary
how may an artefact not be suitable for lab analysis?
once treated with adhesive/fungicide, the artefact may not be suitable for lab analysis, particularly 14C dating
what happens if you can’t store everything?
it may not be possible to conservative and store all the material excavated, it may need to be evaluated to determine its archaeological significance.
what do conservators do?
conservators will determine the most appropriate method for preserving the find. they often specialist in the in the preservation of specific materials.
how are artefacts recorded?
artefacts are recorded via photographs of various angles, illustration of a selective representation of features or 3D modelling
how are artefacts categorised?
excavations can produce 1000s of artefacts and traditionally, artefacts are grouped based on raw materials (ceramics or flints) and attributes (shape or colour). typologies simplify the task of making comparisons between artefact assemblies.
what is the function of artefacts?
the function of artefacts is determined by the context of find, ethnographic analogy or the use-wear analysis (i.e. chemical analysis or residue analysis)
what does magnetic survey do?
magnetic survey within excavation strategy target specific features. its limited excavation focused on answering specific questions.
what must you do when deciding whether or not to excavate?
when deciding whether or not to excavate, you must balance the needs of the modern villages with archaeological opportunity.
why do we excavate and record?
we excavate and record to to provide a detailed record of contexts within their exact locations (within individual trenches and across the site), to maintain exact details of contexts, their relationship to each other within one area and across the site so that the site details can effectively be reconstructed and interpreted both now and into the future
how do we do this?
we do this by using a simple, efficient recording system that helps guide the recording process such as a series of forms from individual context excavation forms to detailed archaeobotanical forms, field notebooks, photographic record and drawn record.
why do we examine stratigraphy?
we examine stratigraphy for building phases, repair to buildings, destruction and separating and numbering finds as related to the above.
what do some areas allow for? how is this useful?
some sites allow for a more detailed reconstruction for past local environment. this informs about the resources available in terms of food and building materials.
what does a wider examination of the environment help us with?
a wider examination of the environment helps us to understand why certain locations were favoured, and why they have gone out of use. a poor or good local environment (including rising water table, ploughing, development) can affect our knowledge about certain materials
what are the different aspects of archaeological recording?
there are different aspects of archaeological recording. the written individual or trench or area notebooks and system of recording forma and the computerised digitisation of drawn record. plans made made using digital surveying equipment, inclusion within a Geographic information system and information concerning objects/contexts input into project database.
when do historical records go back to?
Historical accounts go back only as far as c. 5000 years, earliest writing ans historic records of events emerged c. 5500-5000 years ago. before 5000 years there is a chronological vacuum.
what does the study of stratification of deposits show us?
the study of stratification of deposits or layers and contexts on archaeological sites: the sequence in which the layers were set down or the order in which the layers were set down or the order in which events happened and a context is part of a deposit often relating to a specific archaeological event
what is the accumulation of deposits governed by?
the accumulation of deposits is governed by principals summarized in the law of superposition in an undisturbed sequence of deposits, younger strata will be deposited on older strata.
what do most sites have? can it be horizontal as well?
some sites have deep and complex vertical stratisgraphic sequences. the horizontal relationships between individual archaeological features may give clues about their relative ages.
where are many archaeological finds discovered?
many archaeological finds are made firing field walking or surface surveys. many sites are unstratified: no separate deposition ‘events’ or stratigraphic layers are evident and occupation debris had not built up or has subsequently decayed
what is typology?
typology, a dating device, is the systematic arrangement of artefacts into types. Thompson observed that raw materials used and artefact types change over time
what are artefacts classified and attributed a date based on?
artefacts are classified and attributed a date based on physical characteristics including, raw material, method of manufacture, morphology, presumed function and stylistic attributes.
what limits does relative dating have?
relative dating has many limitations such as statigraphy can’t indicate how long it took for a specific layer or context to accumulate nor can it tell you the date of each stratigraphic layer or context and the typology of an artefact may point to an approximate date, but not an absolute one.
what can chronometric dating methods be used for?
chronometric dating methods can be used to determine the age of an artefact or context and radiocarbon dating or 14C dating is the most widely used chronometric technique
what do all living thing absorb?
all living things absorb carbon from the environment, in plants its via photosynthesis, in animals its via their diet. during life the amount of 14C in any living things reflects the amount of 14C in the environment
how consistent is 14C dating?
14C dates of artefacts of known historical age are not always consistent, calibrating corrects a radiocarbon date to convert it into calendar years.
what does calculating a radiocarbon date depend on?
calculating a radiocarbon age depends on the atmospheric concentration of 14C:12C - the concentration of atmospheric 14C has varied over time
what was the first radiocarbon dating like? how had this changed?
the first radiocarbon dating method used Geiger counters to measure radioactivity, however, in 1977, the accelerator Mass Spectrometer was developed that could directly measure the ratio of 14C to the stable isotopes 13C and 12C
what advantages does this present?
this present 3 key advantages, it uses much smaller samples, its more accurate and its quicker
what limitations does this present?
however, radiocarbon determination cannot date samples older than c.45000 years, a limit imposed by the half life of 14, insufficient 14C is left to give an accurate indication of age and cost.
