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 Subtractive Technology

or

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 18 th arsenic, copper, gold, iron, lead, mercury, tin, and silver. century. Those were 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:

sensitivity. Very thorough.

physical method of determining trace-element concentrations with high precision and

X-ray fluorescence spectrometry:

sample.

An X-ray beam emits a secondary X-ray fluorescence spectrum characteristic of the elements in the

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