arch lecture one

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10 Feb 2011
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Lecture 1
October 28, 2010
Archaeological Data and Dating
x Archaeology is concerned with everyday practises and everyday life.
x For example, tools which were used back in the day as well as pots and bone tools.
x Archaeological Record
o The matrices in which artifacts, ecofacts, sites and other human-manufactured features
or results of past human action are found.
x Three Typical elements of Archaeological research
o Observed materiall culture
o Unobserved human/non-human activity
o Interpretation/explanation of human activity
x Material Evidence
o Physical
o Spatial
Activity areas
x Artifact
o Any portable object whose form has been shaped (i.e., manufactured or modified)by
way of human activity. Ex. Acheulian Hand Axe from Gilan, Iran
x Feature
o Nonportable material evidence of human activity (e.g., hearths, storage pits, postholes)
x Ecofacts
o Non-artifactual material evidence of human activity
o Can be further subdivided into Macrofossils and Microfossils.
o Macrofossils
Visible to the naked eye, e.g. kernel of corn
Can be retrieved through flotation or normal excavation procedures.
o Microfossils
E.g., pollen, phytoligths found in soils or residues adhering to artifacts.
Retrieved through mechanical and chemical disaggregation
Visible only under high-power magnification, 200x or greater.
x Flotation Device
o Water separation of soil matrices
o Used primarily to recover macrofossils
o Lighter materials float to the surface, caught in sieves.
Lecture 1
October 28, 2010
x Poaceae (grass) pollen grains
x Archaeological Site
o Can be defined in a number of ways
o Usually consists of a collection of activity areas containing any of the following:
x Provenience (Provenance)
o Physical location in three dimensional space
o Sith level: grid system
o Regional level: map co-ordinates settlement features (e.g., roads, towns)
x Site Formation Processes
o Affected by:
Human agencies e.g., curating/ discard of objects
Natural agencies e.g., soil composition, environment, temperature, disturbance
by animals (taphonomic processes)
x Finding Archaeological sites
o Field methods
Surface Techniques
x Field walking
x Testpitting
x Aerial photography, satellite imaging
x Remote sensing
Subsurface Techniques
x Excavation
x Remote sensing- resisitivity: measures the resistance of the ground to
an electrical current, current passes more quickly
x DPv}uÇWuµuPv](]oo}ÁZZ[µ(U
some archaeological features (i,e, building materials with iron, hearth
events) have their own magnetic fields.
x Ground Penetrating Radar (GPR): uses radio waves to detect subsurface
features. The stronger the bounce, the bigger the object or feature. The
longer it takes for the bounce to return, the deeper the object or
feature. Only method to provide data along vertical axis of soil matrix.
Benefits of remote sensing
x Cost-effective, efficient and accurate
x Non-destructive and non-invasive
x Devices are relatively portable
x On-site real time data display
Excavation t recovering archaeological data
Lecture 1
October 28, 2010
x Normally begins with a surface collection (if site is ploughed or
x Datum and grid
x Surface Collection
o The spatial distribution of artifacts on the surface of a site is
recorded with reference to a fixed point (datum).
x When excavating, we record subsurface features and the location of
artifacts in a similar fashion
x With reference to a grid system (based on Cartesian coordinates tx and
y axes).
x Types of Excavations
o Open-area, areal or horizontal excavations
o Grid-and-baulk or vertical excavataions
x Horizontal excavations uncover and remove layers (strata) from
youngest to oldest, simultaneously, across a wide area.
x Vertical excavations are focused on a single, small portion of the site.
x Units separated by baulks.
x Screen t considerations: aperture size of mesh
x Stratigraphy: the analytical process by which we order layers and
features chronologically
x Based on the law of superposition.
x Law of Superposition
o Sediments are deposited on top of pre-existing sediments.
x Dating Techniques
o Stratigraphy is a relative dating method.
Levels (and, by extension, the artifacts, ecofacts, and
features contained in them) can be ordered through
time based on their stratigraphic position.
o There are other methods known as absolute dating methods
Radiocarbon dating
PotassiumArgon Dating
Thermoluminescence Dating
o Dendrochronology
Tree-ring dating of preserved wood
Chronologies based on overlapping ring sequences
x Cannot be used in tropical regions
x Confined to certain tree species
o Radiocarbon (14C) Dating