Midterm Exam #2 Flashcards
Geoarchaeology
study, through application of geological principles and methods, of soils, sediments, landforms and stratigraphy in order to investigate archaeological sites and to answer archaeological questions regarding human activity in the past
Sediments
inorganic and organic component of the earth’s surface deposited by natural processes
Soils
in situ developmental sequences
A Horizon
zone of accumulation and elluviation
B Horizon
zone of deposition/illuviation
C Horizon
Parent material
paleosols/buried A Horizons
Matrix
Physical substance surrounding an archaeological find
Provenance
3D position of an object within the matrix
Association
2/more archaeological items (artifacts, ecofacts, features/fossils) occurring together within the same matrix
Primary Context
context of the original context of the find, undisturbed by any factor
Secondary Context
context the context of a find whose primary context has been disturbed by later activity
Systematic Context
manufacture, use, re-use, and discard
Archaeological Context
artifacts continue to be affected by human action and natural processes
Taphonomy
The study of the processes of site disturbance and destruction
An understanding of site taphonomy can help an archaeologist make an informed and cautious interpretation of the past
How Does a Site Get Interred?
Abandonment and Rotting plant matter
Unconformities
Natural geological deposits separating 2 occupational strata
Indicate abandonment
Silt from a river flood
Windblown sand
Volcanic ash
Site Formation Processes - Natural Transformation
Decomposition
Flooding
Volcanos
Earthquakes
Site Formation Processes - Cultural Transformation
Discarding
Recycling
Curation
Deliberate and Accidental Destruction
Relative Dating Methods
Used to date artifacts, features/geological deposits in relation to 1 another
Absolute Dating Methods
Used to measure how old a specimen/deposit on a fixed calendric system
Complicating Factors - Stratigraphy
Mixing: Digging operations turn dirt over and leave it in place in the deposit created by the digging
Filling: A depositional unit is laid down to alter the original level of the ground
Collection: The acquisition and reuse of ancient objects.
Unconformities: Temporal breaks in the stratigraphic sequence as a result of a change that caused deposition to cease for a period of time
Seriation
chronological ordering of a group of artifacts/assemblages where the most similar are placed adjacent to each other in a series
Battleship Curves:
Frequency seriation: Measures changes in the proportional abundance, or frequency, observed among finds (e.g. counts of tools/ceramic types)
Absolute Dating Method - Historical Objects
Uses objects of known historical age to date other archaeological finds
Doesn’t account for shelf life/reuse - date of manufacture not date of use
Historical documents
Works on: previously documented items
Absolute Dating Method - Dendrochronology
A dating method that matches the annual growth rings of an archaeologically recovered wood sample to an established temporal sequence
Complicating factors: not always annual, not all trees have rings, habitat, old wood problem (only marks day when tree was cut down, doesn’t tell if it was used - cultural use)
Absolute Dating Method - Radiocarbon (C14) Dating
A dating method that uses the decay of carbon-14 to date organic remains
Most commonly used
Complicating Factors: Limited in more recent materials (pollution), only up till 1980
Works on:
Wood, charcoal, ivory, plants, shell, bone, and other organics - anything with significant amount of carbon collectant
Absolute Dating Method - Accelerator Mass Spectrometry (AMS) Dating
A newer, more accurate form of Radiocarbon dating - gives smaller range of date
Accelerates ions to high energies before mass analysis (several percent the speed of light)
Absolute Dating Method - Uranium Series Dating
Measures the decay of uranium isotopes found in calcium carbonate deposits
Uranium (235U and 238U) decays into other isotopes (such as 230Th, thorium).
Works on:
Limestone bedrock, cave deposits (stalagmites, flow stone)
Finds between 50,000 and 1 million years old
Absolute Dating Method - Thermoluminescence Dating
Thermoluminescence dating reheats samples to emit photons
Measures trapped electrons in surrounding radioactive material – annual dose radiation in sediment - to determine calendric age
Only works on objects that were heated in the past, can’t date recent items either