ARCHAEOLOGICAL
MATERIALS
Raw materials make up a large part of what is recovered in the
archaeological record. Most inorganic remains are derived from
geologic materials.
The raw materials used by our early man would have consisted
of stone, bone, clay, fiber, metal, shell, textiles, skins, hair, hide,
and wood.
Of these stone and clay have attracted the most archeological
interest and has provided the foundation for classification of
many prehistoric cultures.
Why?
Mostly because bone, fiber, and hide do not survive well in the
archaeological record and metals required smelting which is a
technology that came into use in SW Asia only 5000 years ago
and in the Americas only 2000 years ago.
So what do we do with this raw material?
One of the main things we want to do with raw materials
identified at an archaeological site is to determine is
provenance.
What’s the different between provenance and provenience?
Provenience vs Provenance
Provenience is a common archaeological term referring to
the exact 3D location at which an artifact was recovered
within its matrix. Without knowing Provenience the artifact
has little value.
Provenance is the origin of the raw material used to make
the artifact that was discovered.
Provenance studies do not address where an artifact was
manufactured, but simply where is the source of the raw
material used to manufacture the artifact.
What are some materials commonly
found in the archaeological record?
Stone
When many people hear the word stone they often think of
rocks and minerals.
Let’s begin with some basic definitions:
Rock
Mineral
Stone
Rock
Rocks are specific aggregates of one or
more minerals that occurs commonly
enough to be given a name (limestone,
granite, etc).
The major classifications of rock are:
Igneous: formed from molten magma
Sedimentary: formed from the consolidation
of deposited clasitc (or fragmented) particles
Metamorphic: formed by major alteration of
preexisting rocks due to high temps and
pressure.
Mineral
A mineral is a naturally occurring inorganic
element or compound having a specific
crystalline structure and a unique chemical
composition (quartz, mica, etc).
Obsidian for example is a rock, but it is
volcanic glass that has not yet crystallized.
Examples of Minerals in the
Archaeological Record
Obsidian
Major trade object in the early human prehistory of the
“New World”
Obsidian forms in lava flows and as blocks in tuff from
explosive volcanic eruptions.
Nearly all obsidian originates from volcanic arcs or chains.
Chert
Micro crystalline quartz with few traces of chemical
impurities.
Considerable visual variability
Stone
The word stone actually has many meanings.
Stone tools were the earliest artifacts, associated with one
of human’s earliest ancestors Homo Habilis.
Stone Tool Traditions
So what do we mean by traditions?
The tradition was much more than the making of tools. It
was culture.
Tool technology changed culture in that food choices were
able to be expanded, clothes were able to be made,
common necessities such as needles and utensils were
able to be sculpted, the ability to treat and heal wounds,
etc.
Oldowan Tradition
This is the oldest tool tradition
(associated with Homo Habilis),
relying primarily on the
percussion method. The
percussion method was made
by striking a stone or against
something to remove flakes,
until it was in the desired shape.
The Oldowan tradition was the
primary method of stone tool
production until they began
making tool flakes on both
sides, moving us into the
Achulean tool tradition.
Percussion Method
The shaping of stone depends on the
property of the conchoidal fracture,
which means that stones break in a
predictable way when struck vertically
which produce cores or flakes which
allow archaeologist to identify the rock
as humanly modified.
This is known as Reductive or
Subtractive Technology
Acheulean Tradition
Achulean tradition was
utilized by Homo
Erectus, and
characterized by a tear
drop shaped tool with a
pointed tip and cutting
edges all around. It
became one of the first
hand axes (derived from
the Oldowan Tradition).
Levalloisian Technique
Levalloisian tradition tools
were produced by removing
three or four “flakes” from a
stone’s surface by striking
the stone against a striking
surface, thereby removing
flakes of predetermined
shapes and sizes.
At about the same time
hafting emerged
Drawing A shows the preparatory flaking of the stone core; B, the same on
the top surface; C, the final step of detaching a flake; and D, the final step of
detaching a flake of a size and shape predetermined by the preceding steps
Invention of Hafting
Hafting is affixing small stone
bifaces and flakes in handles
of wood to make spears and
knives.
It involved three components:
handle, stone insert, and
binding materials.
Regional stylistic and
technological variants are
clearly evident, suggesting
emergence of distinct cultural
traditions.
Mousterian Tools
This stone tool tradition used by
the Neandertals (and other
members of genus Homo of this
time).
This tradition is similar to the
Levalloisian Tradition in
methodology; however, smaller,
sharper flakes were created.
In addition the variety of tools
increased to include hand axes,
flakes, scrapers, borers, notched
flakes (for shaving wood), and
more.
Other Definitions Pertaining to Stone
Lithic analysis is the study of stone artifacts and
technology, is based not only on the identification of
attributes and types, but on the actual reconstruction of the
reductive technology used to make them.
Petrology, or the study of rocks, has been very successful
in gaining an understanding about the rocks from which
stone tools are made.
Other Materials Found in the
Archaeological Record
Clay
Metals
Bone
Wood
Clay
The primary raw material for archeological ceramics is clay-rich sediments. The term
ceramics has been translated to mean “earthenware” or “burned stuff”. Ceramics
includes products that have been fired including pottery, brick, tile, glass, plaster, and
cement.
Therefore, we will primarily use the term pottery which is the general term for artifacts
made mostly of clay.
There are two types of clay deposits: primary and secondary.
Primary deposits are formed by weathering of bedrock.
Secondary deposits are formed by river or lake deposition.
Clay containers and their fragments have the advantage of surviving which makes them
important to the archaeology record.
Their shape, form, and style have been the basis for numerous archaeological analyses.
Metals
Metals were familiar to ancient peoples in the form of rocks in their environment.
Only eight metals were acquired and manufactured prior to the 18th century. Those were
arsenic, copper, gold, iron, lead, mercury, tin, and silver.
Only gold and copper where available in their native state and were most important to
early societies.
Copper was the earliest metal tool to be manufactured around 6000bc. By 3000bc metal
workers learned how to alloy the metals.
The word ore means a lump of metal. It is applied to an aggregate of minerals from
which one or more metals can be extracted.
Another important metal…
Hematite- aka “Red Ocher”
is a red iron oxide called hematite also known as red ocher
has been used for decorations since at least the
Mousterian tradition (cave paintings in France and
decorations discovered on pottery).
Other Metals
…don’t bother copying this down this is just for your information
Complex Copper Minerals
The smelting of copper goes back six millennia
Sulfide copper proves harder to smelt than regular copper.
Tin
Very important to metal-using societies but often not awarded the credit
for it.
Essential component of bronze and pewter
England housed the largest old world producer of tin, Cornwall
England.
Lead, Silver, Gold.
Derived from smelting of lead minerals appear in the late seventh
millennium.
Most lead can be sourced fairly easily.
Major trace impurities in gold make it difficult however, to source the
gold.
Bone
and
Wood
Bone material was probably in use as early as the beginning of human history.
Specialized tools such as spear points, harpoons, fishing spears, needles and
more have been found in the archeological record. Like bone, wood was used
for human artifacts from the earliest of times.
Only rarely do these artifacts survive however.
The oldest surviving wooden artifact is a 400,000 year old long wooden
throwing spear from Germany.
The manufacture of wood tools involves well understood mechanical processes
such as cutting, whittling, scrapping, carving, and polishing.
Wood was probably the most important raw material available to our ancestors
as it was in abundant supply and easy to manipulate.
Sourcing Methods
Similarly to how we used DNA to trace origins, Geologist use trace
elements, isotopes, diagnostic minerals or assemblages, micro fossil,
geophysical properties, and other measures to determine the source or
origin of geologic materials.
Problem with some key sourcing methods are: they are destructive.
Trace element analysis: small samples, chemical, and non destructive
Instrumental neutron activation analysis: physical method of
determining trace-element concentrations with high precision and
sensitivity. Very thorough.
X-ray fluorescence spectrometry: An X-ray beam emits a secondary
X-ray fluorescence spectrum characteristic of the elements in the
sample.
Isotope Analysis: determination of isotope abundances or ratios is
made with a mass spectrometer. Ions of specific masses are collected
and counted electronically.
Sourcing Geologic Deposits
To establish and define a potential geologic source (or
provenance) through trace-element concentrations it is
necessary to do three things:
1.
Establish the geologic uniqueness and boundaries of
the deposit.
2.
Collect and analyze ten or more samples that are
widely dispersed statistically throughout the deposit to
establish the complete range of variation.
3.
Researchers also need to determine whether modern,
large scale mining or quarrying techniques have
obliterated deposit exploited in ancient times.
Sourcing Summary
Finding the source of material from which an artifact was
manufactured or the materials were derived from is
extremely important. This allows us to explore patterns of
exchange and trade routes, in addition to providing
information on the size and location of resources that were
available to groups and relate these resources to social
stratification patterns and the organization of crafts and
industries.
Notes
• Don’t forget that our last Brown Bag is this Friday
• Make-Up Exams will be offered the week we return from
Thanksgiving (this is the ONLY time)… contact me if you
need to make up an exam