Unit 2: Adventures in Archaeology

Ferraro Chapter 1 pp. 7-9

Archaeology 101

Artifacts

refuse, remains

lithics

ceramics

wood and bone tools

metal and glass

textiles

Fossils

Features

ex. fire pits, borrow pits, buildings, habitat floors etc.

Site

stratification — what does this tell an archeologist?

Taphonomy – what is it?  how does it interfere with archeological study?

Full excavation v. sampling

Site survey methods – pedestrian survey

remote sensing

How context affects what is learned from artifacts.

the battle between preservation and excavation;

also between preservation and the public’s right to use public lands

threat to archaeology from looters

why interpretation of a site can differ between archeologists

what is the function of archaeology in the modern world?

 

Embers Ch 2 — PP. 15 –

> most artifacts are items that have been lost or thrown away and are not intended by their “makers” to carry any special message

> lithics are the most common artifacts from the past – stone tools

Humans first used stone tools 2.5 million years ago – some are still used for polishing or grinding work – but they have been used for any number of purposes (Venus of Willendorf).  Most tools we find and think we can identify from prehistoric societies have to do with hunting butchering and hide processing

>ceramics – first appear in the human record about 10,000 years ago – pots or other items made of clay – storage or cooking vessels.

> wood and bone tools – probably just as common but do not survive as well except in exceptional circumstances

> metal and glass – can be common artifacts in later societies, survive well and are found usually close to where they were created and used.

Ecofacts – natural objects that have been used or affected by humans.  EG – bones of animals that people have eaten – not intentionally modified by humans but used and discarded;  also pollen from plants found because the plants were transported and used by humans;  insect and animal pests (cockroaches, mice) drawn to a particular location by the presence of humans.   Anything that is in a particular place because of human activity is an ecofact.

Fossils – rare, caused under special circumstances when minerals bond with the plant or animal bones or teeth or other materials and making them less likely to deteriorate.

Human fossils are spotty and of the estimated 6000 primate species that have ever existed fossils have been found for only 3%. (18 – 20?)  Makes it hard to make the evolutionary record connect.  Small fossils are harder to find than those of larger creatures.

Features – artifacts that cannot be easily removed from a site.  Hearths are effected by human activity but nearly impossible move – other examples include pits (garbage pits, borrow pits – identifiable because the variety of soils found in them.  Living floors, where people lived and worked are covered with the detritus of human occupation  imbedded in the floor, buildings, stone rings,

sites —  known or suspected locations of human activity in the past that contain some record of that human activity that have been covered or buried by some natural process or have been covered by subsequent layers of occupation (layer cake).  where this occurs quickly enough to create stratification it can be possible to date the artifacts and tie them to a specific era in the site’s use.

taphonomy – wind and water erosion may bury materials or displace them entirely – it is possible to collect information from artifacts in this state but not in the same was as if they were found in situ, or where they were originally used.

> pedestrian survey – the old fashioned way, walk the area and look for evidence of human activity

> remote sensing – methods borrowed from exploration geology where anomalies are found either in the earth’s surface or where a pulse or a sensor deviates to indicate the presence of something — GPR = ground penetrating radar can give the archeologist a good idea what is below the surface

> geomagnetics –  magnetometer where extra high or low readings will indicate the likelihood of a site this technique is sometimes used to map walls and pits below the ground before the  site is even excavated.

> satellite location —  satellite photography is being used to locate large sites or sites in jungle areas that are difficult to spot from the ground or from close aerial observation – this method has been extremely effective for locating sites in dense foliage and heavily forested areas.

There is only one way to recover artifacts – excavation. Full excavation is rare

>expensive

> time consuming

> may not fully have the resources to study what is found, save some for later

so instead – sampling

Archeologists and paleontologists use the same methods but look for different things.

Archeologists prefer undisturbed sites but either will dig wherever they believe they are most likely to find what they’re looking for.  Paleontologists like disturbed sites because it may save them time finding fossils but sometimes find great things in undisturbed areas. Paleontologists are looking for individuals, archeologists are trying to piece together a story.

→ Green Sahara — the big desert wasn’t always empty!  This is a great article about how cultures follow one another and how you can tell them apart archeologically.

Analyzing the Evidence P. 19 Embers

Once you’ve collected artifacts and materials from a site it’s time to analyze or “read” what you’ve found.

Before this information can be collected the finds must be conserved, and sometimes reconstructed.

Conservation – the process of treating artifacts, ecofacts and sometimes even features to stop decay and deterioration.

>Can be as simple as cleaning and drying an item.

>Can be long-term treatments involving complex chemical processes.

Sometimes long term storage under carefully controlled conditions is necessary.  EG:  Ice Man – 5000 year old individual found in 1993 in the Italian Alps is kept in glacier-like conditions when it was discovered that studying him at room temperature was causing him to develop mold.

Reconstruction is like a rebuilding a puzzle, usually without all the pieces – and sorting and identifying and reassembling a given artifact can sometimes take years.

Sometimes later researchers will review previous work and interpret the

artifacts or materials in a new way – T-Rex fossils.

Different methods are used depending on the artifact to be analyzed but there are commonalities across the board….

1.  Examine the form of the artifact – how is it shaped?  Most lithics and ceramics are well enough known to allow a typology to be established.  EG:  Clovis points, Mesa Verde corrugated pottery vs. black and white pottery – all identified as to likely time and place of fabrication.  This puts the artifact in context with others like it both within the site of origin and with others like it found in other sites. (Age, species, or culture with which it is affiliated – maybe even how it was made, used or exchanged as a trade good in the past)

2.  Measure the artifact – allows for less subjective analysis of the artifact, and gives information about materials that are incomplete and not necessarily indicative of their larger form.

3.  Determine how the artifact was made – what is it made of?  how was that material it manipulated/constructed?  tells much about the technology, economy and exchange systems of the people who made it.  in some cases it is possible to link the artifact to manufacturing techniques still used today in the same area. – Pottery, weaving, toolmaking, frequently are done the same way within a culture for centuries.

4.  Understand how the artifact was used – gives a window into the culture.  Use-wear analysis for stone tools may indicate how and for what a tool was used.  Residue from ceramics may tell us how that vessel was used.—EG – yellow residue from Turkish pottery turned out to be barley beer and provided evidence of earliest known brewing in the world from pottery known to date from 3500 to 3100 B.C.

Put all this information together and you begin to build a picture of a society.

typologies (classification of things according to general type, used in archaeology, psychology and other social sciences, and the study or analysis of things according to classification) allow anthropologists to draw connections between groups – how information may have been shared, how they were organized socially, what trade may have occurred between them.

knowing how artifacts are made (and what its made of) allows us to understand the technology and technical ability of past people based on the complexity of the processes used and may relate to the level of cognitive ability of the individuals.

knowing how an artifact is used gives us a picture of the people who used it — Homo Erectus tools have been shown to be complex and used for a variety of applications, kind of a stone aged Swiss army knife, and indicates a level of sophistication of thought and reasoning of those individuals – something that could not be drawn strictly from the fossil record.

Can be used to reconstruct ancient environments (presence of certain pollens, animal remains, etc. may indicate shifts in climate or cultivation, or domestication of wild species – cats)

Paleontologists can tell a lot from analyzing a fossil using not only dating techniques but also comparative anatomy – looking at the fossil compared to other known animals of the same or similar species (dinosaurs – lizards or birds?), and to fill in the blanks of the fossil record. Electron microscopy, CAT scans, biometric modeling are used for non destructive analysis of fossils, microstructure of bone and teeth, how the organism developed.

P’s also look at the surrounding areas of fossil finds to gather evidence about time, environment/climate, habitat of the critter.

Teeth become an important part of the this analysis because they can tell us where to place the individual in evolutionary time, size of the animal, diet (flattened teeth of vegetation eaters versus the pointed teeth of carnivores – so what are we?  how can you tell?)  patterns of growth give us information about development of the species.

Fossils also tell us how the creature moved (locomotion)  — bipedal or quadraped?  long fingers may indicate a creature that climbs, leaps needs more grabbing power, more powerful back limbs may indicate leapers, longer front arms brachiators.  Marks on bones may indicate patterns of muscle attachment, skull size usually relates to brain size and tell us about capacity for memory, vision, smell.  Protruding snouts indicate more reliance on smell, position of eye sockets on the head may indicate nocturnalism, or the position of the animal as predator or prey.

Features – can’t be moved so must be studied in place.  Mapping, measuring, comparison with other sites of similar age may reveal patterns in the archeological record. A building’s size, purpose, arrangement tell much about a society that occupied it. Sometimes social structure, changes in culture, political structure, can be deduced from how, where, and what a building is used for.  The materials, techniques of construction and the architecture may reflect the level of complexity of a society, the possibility of stratification of wealth, power, influence within a population.

all of these kinds of data are fairly useless when considered alone. Information gathered from excavation at a given site must be considered as a whole and then compared to the body of knowledge that is already accumulated in general. When combined it gives a more complete picture of the past that we can “read” today.  Interpretations of data may change over the years as more information comes to light, but very little is learned by isolating information.

Relative dating – figuring out how old something is by its relationship to other stuff

In general: the deeper something is buried, the older it is. Stuff that is found closer to the surface is usually newer in age than artifacts that are found deeper in the ground. This is NOT always the case, but for the most part unless something is intentionally buried deeper than the habitation layer, or if things become disturbed in some fashion

The earliest and most commonly used method is stratigraphy – (the study of how different rock formations are laid down in successive layers or strata; the order and position of layers of archeological remains).  The deeper the layer the older it is.  Evidence especially fossil evidence in the different layers may be used to determine relative age of other sites around the world – meaning those layers with distinctive fossils would have been laid down at the same time. This only works in undisturbed areas where the evidence and the layers are intact.

A more complex relative dating method: For disturbed sites the evidence may be dated by determining chemical content of the material or the “FUN” method.  Buried in the ground for long periods of time bones and teeth accumulate minerals from the groundwater in the area.  Fluorine and uranium increases with age, nitrogen decreases. So an artifact can be dated by the relative content of these minerals it contains BUT–> The problem is that different sites have different mineral content so this can be problematic – a 30 million y.o. fossil from one site may contain the same level of fluorine as a 50 million y.o. fossil from another.

Issues with this method of dating:  Fluorine and nitrogen testing require some destruction of the material.  Uranium can be tested through radioactivity, and without destruction of the fossil.

The combination of these three tests can sometimes be used to get a read on age, where the use of any alone does not provide enough information.

These tend to be more complex processes and  there are lots of these, let’s concentrate on just three….

Most of these methods are based on the decay of radioactive isotopes.  Because the rate of decay is known the age of a specimen can be estimated with in a range of possible error.

Radiocarbon dating – charting the level of carbon 14 left in a specimen that once was alive may determine how long it has been dead.  Limitations though – good up to 80,000 years

Thermoluminescence – dating based on the amount of light given off when minerals are heated and electrons are released, because more electrons from radioactive elements are trapped over time more light will be emitted from older samples.  Good for pottery, bricks, tile, lava, hearthstones, meteorites and meteor craters – anything that was formed by the use of intense levels of heat as part of its creation.

Paleomagnetic dating – determining the magnetic orientation of the earth when rocks are formed allows rocks to be match to a specific period where the magnetic field was in that configuration.  Problematic because of the precision necessary in documenting the material in situ, material moved after the rock is cooled will cost valuable information.

The goal of archeological research is the description or reconstruction of what happened in the past. Archeologists attempt to determine how people lived in a particular place at a particular time and when and how they change and adapted their survival strategies, living patterns and beliefs over time.  They also try to learn when and how and why new cultures may come to an area, or when and why older cultures may leave. This is called cultural history – the rise of agriculture, the rise of cities, the effects of the climate and climate change on a given area, or as a catalyst for variations in human culture these are the things archaeologists study.

Archaeology is used to track the physical evolution of humans and the evolution of their cultures and across time.

Unfortunately there is the crazy side of archaeology that takes valid research to support some fairly wild ideas. If you don’t know what I’m talking about have a look at this Discovery Channel program about aliens and the pyramids….sheesh.

Any questions?  Come see me.