Methods of studying the past: Archaeology & Biological
Where did people live?
Archaeological sites; where people lived or carried out activities
Artifacts; objects made by people
Ecofacts; ecological debris such as animal bone
Features; nonportable remains graves or walls.(Foundation or buildings)
-sources of water, clay, iron ore, firewood etc
Local and oral histories:
- troy/Heinrich Schleimann
-Electrical Resistivity Survey
-Ground Penetrating Radar
-Random Testing; Test Pitting
-Inform us on where to look and where not to look
What materials did they leave behind?
-Spatial contexts/ associations; keep each item seperate
-provenience; relation in 3d space that each artifact has
-assemblage; relation between all artifacts in that same area
Sieved; remove dirt/sediment
Sorted -> sent to lab for analysis
When did human activities occur?
Relative dating methods:
-Stratigraphy, Seriation, Self dating, and Cross-dating
Absolute dating methods:
Dates in the Distant PAst: BP - 1950 AD
YA - Years ago
KYA - Thousands of years ago
MYA - millions of years ago
Dates are usually averaged over spans of many years.
i.e “1,000,000 years ago” really means something between about 900,000 and
Stratigraphy & Law of Superposition
Sediment on top of already existing material, recent on top, older on bottom.
Exceptions: Animals burrowing or Earthquakes can disturb the age in the deposits.
Measuring change through time due to changes in technology, raw materials or styles of
Styles appear, gradually achieve some measure of acceptance, and then
becomes outdated and gradually disappear.
At the same time that old Style A is disappearing, Style B is reaching its
maximum extent and new Style C is just appearing.
Objects which have actual dates on them:
-Coins, tombstones, letters
Objects which reflect events of known date:
-A basketball, for example, dates after the invention of the game in December
Remember that people save souvenirs:
-Cannot date from a period earlier than that date
-May date from a late rperiod
-Restricted to the last 2000 years or less.
Sites or strata with similar fossils, artifact styles, or technologies are similar in age.
Dates are obtained from multiple sites and if they contain similar artifacts one can infer
that certain layers are similar in age.
Every year, every tree and bush grows outward by adding a layer of wood around its
trunk, These annual layers are light in colour.
-In good years, the tree grows a lot and its light coloured layer is wide;
-In bad years the tree doesn’t grow as much and the light coloured layer is
When a tree is cut down, one can tell how old it is by counting the number of rings
(annual growth layers) from its edge to its centre. By matching old tree trunks and matching it with recent ones, we can match the pattern
of the rings in order to indicate the age of the trees.
Radiocarbon (14C) Dating
All forms of life contain carbon
-So does food that organism eat every day
-Living organisms constantly replenish 14C atoms through the food chain.
Carbon exists in three forms or isotopes.
-Carbon 12 is common and stable (99%)
-Carbon 13 is rare and stable (<1%)
-Carbon 14 is very rare and radioactive
14C 12C = 1
14C atoms have a half life of 5,730 years
-Pick a leaf today: estimate the number of carbon atoms present in the leaf by weight
-Calculate the number of 14C atoms
-If you re-measure that same leaf 5730 years from today there will be exactly half
as many 14 C atoms, Half will have reverted to stable 14N
-By measuring the amount of carbon in a sample and comparing