Presentation on theme: "How do we know about the past?"— Presentation transcript:
1How do we know about the past? Methods of Historical Investigation
2Primary and secondary sources Primary sources are those that come from the time being investigated.Secondary sources are written or produced after the period they describe.LettersSpeechesEyewitness descriptionOfficial documentsModern historianTextbookEncyclopaediaRe-enactments
3Types of Sources Histories Plays and poetry Legends Letters Written Sources include:Non-written Sources include:HistoriesPlays and poetryLegendsLettersInscriptionsLawsAdministrative RecordsGraffitiBuildingsMonumentsTombsSkeletal remainsPotteryTools and weaponsHousehold goodsCoins
4How reliable are our written sources? Truth or bias?Purpose for writingPersonal beliefs or opinionsLimited access to evidence
5What is Archaeology?Archaeology is a way of studying the human past through physical remains (artefacts).Artefacts are any objects made, used or modified by humans.Archaeologists are Time Detectives
6Investigating the Evidence ObservationWhere was the artefact located?What is its possible age?Who made it?What might it have been used for?Who put it there?Classification & RecordingClassifying according to time and placeIs it authentic?What can be learnt from it?Does it contradict or complement other evidence from the site?InterpretationInterpret the evidenceLook for patternsWhat conclusions, inferences or assumptions can be drawn?
7How are artefacts dated? Relative Dating MethodsAbsolute Dating MethodsStratificationTypologyCross-datingFluorine testingPaleontological datingPollen analysisCarbon-14 datingPotassium-argon datingDendochronologyThermoluminescenceIntel Education: Student Login
9TypologyMany artefacts can be dated according to their style. For example, pottery, tools and weapons show distinct styles at different periods of development (compare with how models of cars have changed over the years).
10Cross-datingIf a particular style of helmet, pottery, etc is able to be dated at one particular site, then this can be used to date other sites in which the same style of artefact is found.
12Paleontological Dating Palaeontologists study the history of animals. Often a site can be dated according to the types of animal fossils found there.
13Pollen AnalysisCranesmoor bog is formed over lake muds estimated from pollen analysis to have been laid down in early Boreal times, and the overlying peat is up to 15 feet deep in parts. The peat consists mainly of either Sphagnum or Schoenus nigricans remains, and the present surface vegetation shows a similar variation associated with hydrological differences in different parts of the bog. [Information from a botany report available on the "New Forest History" website: ]
15Potassium-argon Dating The landscape in the central Andes Mountains, near the border between Chile and Argentina, is dominated by volcanoes and associated landforms. Layers of older sedimentary rocks are visible to the upper middle, and many volcanic cones show grooves where water has eroded the rock to form gullies. A few volcanoes exhibit much less erosion, and even show tongues of dark, recent lava flows (upper left).
16DendrochronologySample from wood is taken with hollow drill. Samples from woods those have partly different age, can combine together to make tree-ring sequence, that can be presented like thicker tree or longer stick.Drill to take samples for Dendrochronology from trees
18Comparative Chart: Dating Methods Can tell us:AccuracyWhat ?Any ProblemsStratificationThe order of occupationRelative only – earlier or laterAny finds in situTypologyApproximate date madeRelative only - new/late modelMan-made itemsCross-datingNot earlier than...Relative: one find used to date otherFluorine TestingTime of burialRelative only (see problems)Bones, teeth, antlers, ivoryTemperatureSoil chemistryPaleontologicalWhat animals?Appearance and extinction periodAnimalsPollen AnalysisEvidence of climateGrains will survive for 1000s of yearsPlantsOnly history of the vegetationCarbon-14Time of death+ or – 100 yearsTo 50,000 yearsOrganic material (certain amount)DestructionContaminationPotassium-ArgonAge of rock layersTo millions of yearsVolcanic RockLimited sitesDendrochronologyAge of timberDates layer to yearTimberRequires time sequenceThermo-luminescenceOriginal firing date> TypologyTo 35, 000 yearsFired pottery & clay