Archaeological Excavation Strategies

• Excavation strategies aim to uncover horizontal space.

Excavation Strategies

• Trenches: These are used to expose strata, which allows you to see the vertical strata.

• Excavation Block: These provide good horizontal coverage.

• A disadvantage of this excavation strategy is that you lose all internal profiles.

• Rice-Chex/Ice-Cube Tray Method: Involves leaving a balk or space on the grid between each unit.

• A positive aspect is that profiles (balks) are preserved in the middle of the excavation block.

• Negative aspects include: both planview and profile are discontinuous and balks are fragile.

• Checkerboard Method: This divides the excavation area into a grid, excavating every other unit.

• Positives of this method are saving 50% of the archaeological record, reducing the amount of earth moved, and facilitating future replication of work.

• Negatives of this method are the horizontal plane is discontinuous and features may be broken up.

• Trench-Block Method: involves placing four trenches around a block to expose stratigraphy.

• Positives include ultimate stratigraphic and horizontal control for the central unit.

• Negatives include difficulty in implementation and dependence on knowledge of the middle block's contents.

• Expando-Trench Method: This involves excavating a trench in arbitrary levels, then smaller blocks stratigraphically, stepping out.

• A positive of this method is that it provides stratigraphic control progressively across the horizontal dimension.

• A negative of this method is that planview assembly occurs in the lab.

Excavation: Additional Concepts

• To decide where to excavate using probabilistic methods is the same as deciding probabilistic methods for site survey, for example stratified random

• To decide where to excavate using judgement/haphazard methods includes the following

  • High concentration of artifacts
  • Areas of particular interest
  • Features visible
  • Remote sensing indicates stuff below
  • Land form (geological feature)
  • Soils

• Datum Plane: An arbitrary horizontal plane across the site from which vertical distances are measured.

Excavation Levels:

• Arbitrary Levels: Vertical units of equal size are used (e.g., 5 cm, 10 cm, or 20 cm).

  • Pros include suitability for ubiquitous soils and speed.
  • Cons include the potential to mix artifacts from different stratigraphic levels.

• Natural Levels: Collecting all material within individual strata.

  • Pros include no chance of mixing.
  • Cons include being finicky to follow.

Problems: The Horizontal Plane or Vertical Plane

• Problems can occur when you can't see both planes at the same time, and usually have to sacrifice one for the other

Archaeological Record and Context

• Archaeological Record: Modern empirical traces of past human behaviors.

• Archaeological Context: The processes that happen to artifacts after they enter the ground, including movement by mechanical processes and alteration by chemical or mechanical processes.

• Systemic/Behavioral Context: Artifacts have a life history: procurement, manufacture, use, recycle, loss, discard.

• Michael Schiffer: Focused on N-transforms and C-transforms, advocating consideration of N-transforms before C-transforms.

• N-transforms: Changes in site/artifact state caused by natural processes.

• C-transforms: Changes in state caused by human behavior (cultural processes).

• Positive Evidence: Something tangible at a site.

• Negative Evidence: Absence of something at a site.

Reasons for Missing Items

• Reasons why items may be missing from the archaeological record:
  • Not there in the first place
  • Looked in the wrong place
  • Failed to recover it in the right place
  • Material was not preserved

Preservation Factors

• Preservation [P = (M, C, D, S, T)]: Consists of Material, Climate, Deposition, Sediment, Time.

Material:

• Material: What an artifact is made of.
  • Perishable: Usually not present (e.g., flesh, flowers).
  • Altered: Present but chemically and/or mechanically changed (e.g., wood, hair, bone, metal).
  • Imperishable: Present with minimal change (e.g., stone, ceramic, charcoal).

Climate:

• Climate: The climate in which the artifact is deposited.
  • Temperature: Heat speeds up decay, cold slows it down.
  • Precipitation: Wet speeds up decay, dry slows it down.

Deposition:

• Deposition: How the artifact is buried.
  • Rapid Burial: Usually results in better preservation.

Sediment:

• Sediment: Nature of the sediment; the most important factor is pH.
  • Acid pH: 1 - 4
  • Neutral pH: 5 - 8
  • Basic pH: 11 - 14

Time:

• Time: Duration of time all other forces are active since deposition.
  • Longer time in the ground typically results in less preservation.

Deposits:

• Primary Deposit: Artifacts are right where they were put, reflecting human behavior.

• Secondary Deposit: A primary deposit which has been moved naturally, rarely reflecting human behavior.

• Mixed Deposit: Deposit itself is primary, but the material is mixed in place, associations may not reflect human activity.

• In Situ: Artifact found such that archaeological provenience is exactly known.

• Pompeii Premise: Snapshots in time where everything is frozen with minimal distortion.

Classification and Typology

• Classification: Enhances communication, organizes stuff, and may reveal previously unperceived aspects.

• Variable/Attribute: A property that can vary or differ from specimen to specimen.

• Qualitative Variable: Variance in quality or kind (e.g., dead or alive; male or female; chert or obsidian).

• Quantitative Variable: Variance in magnitude (e.g., length, width, weight).

• Class: A definition of the specified necessary and sufficient conditions for membership in a group.

• Type: A description of an average looking specimen.

• Typology: A set of types or set of descriptions.

• Identification: The process of placing a new specimen within its proper class.

• Classification Units: Classes or types.

• Morphological Types: Descriptive types designed to reflect the overall appearance of a group of specimens by simultaneously considering as many variables as possible.

  • Procedures: Make piles of similar stuff, write a general description of what an average specimen in each pile looks like.
  • Advantages: Easy to implement, good for descriptive purposes.
  • Disadvantages: Types not amenable to analysis, hard to replicate between investigators.

• Functional Types: Types constructed on attributes relevant to the artifact's function.

  • How: Analogy, use-wear.

• Temporal/Historical Types: Defined on the basis of attributes or attribute combinations that have a limited range in time.

  • Method: Dig a site, stack layers of types to test, if it works result is historical type(s).

Lithic Technology

• Lithic Technology: Stone technology, a subtractive technology.

Making Stone Tools:

• Approaches: Chipping/Flaking (flaked stone tools), Pecking/Grinding (ground stone tools).

Chipping/Flaking Properties:

• Must have properties: Brittle (like glass), Homogeneous structure, Small grain structure, Hard (to withstand use).

• Fracture Mechanics: Given the material requirements, we can predict how a rock will break. stone will fracture conchoidally if the material requirements are met.

• Conchoidal Fracture: Waves from the force of impact move through the stone like water waves in a cone shape.

Chipping/Flaking: Rock types

• Types of rock that fracture conchoidally: Volcanic, Sedimentary.

• Volcanic: Obsidian, Basalt, Andesite, Rhyollite, Trachydacite, Quartz, Quartzite.

• Sedimentary: Chert/Flint, Chalcedony, Jasper, Agate, Opal, Silicified peat/siltstone/sandstone, Porcelinite (lightning hit coal).

• Debitage: All the waste material produced during stone tool manufacture.

• Core: A chunk of stone from which flakes are struck.

• Flake: Pieces of chipped stone where the length is less than 2 times the width.

• Blade: Flakes that have a length 2 times greater than the width.

• Hard Hammer Percussion: Hammer is harder than the flake being worked

  • Flakes produced tend to be short, wide, and thick with a fat bulb.

• Soft Hammer Percussion: Hammer is softer than the flake being worked (e.g., antler, bone, wood, or soft stone).

  • Better control of flaking due to energy dissipation, flakes are longer, thinner, and have thinner bulbs.

Pecking:

• Pecking: Involves removing pieces of stone from the object being manufactured using a percussor or hammerstone that is of equal or greater hardness to the piece being altered.
  • This is a slow process.

Grinding:

• Grinding: Involves using abrasion to work stone.
  • The abrader must be of equal or greater hardness to the stone being worked, often performed with some form of abrasive and lubricant.

Grinding: Three Methods

• Three Methods: Simple grinding, Sawing, Drilling.

• Sawing: One of the three main methods of grinding

Lithic Reduction Stages:

• Reduction stages: Early, Middle, Late.

Chipped Stone:

• Chipped Stone: Advantages

  • Relatively quick to make, approximately 20-25 minutes
  • Produces sharp cutting edges.

• Chipped Stone Advantages:

  • A limited number of shapes can be made.
  • Tools are not as durable.

Ground Stone:

• Ground Stone: Advantages

  • Make any shape of tool
  • Any type of rock can be altered
  • Often are very durable

• Ground Stone: Disadvantages

  • Very slow to manufacture.
  • Working edges are not as sharp.

Ceramic Technology

• Ceramics: Artificially bonded non-metal earth materials, typically clay.

• Clay: Fine grained earthy material that develops plasticity when mixed with water.

• Temper: Aplastic filler used in clay to help control shrinkage and lower required temperature during firing (e.g., crushed rock, shell, bone).

Shaping: Methods

• Methods of shaping: Modeling, Coil Construction, Molding, Wheel Turned.

• Modeling: Manipulating paste into desired shape by working, beating, pushing by hand.

• Coil Construction: Most widespread method.

  • Lumps of paste rolled into long ropes.
  • Ropes are coiled up.
  • After coiling, often a paddle and anvil are used to strengthen vessel.
  • Paddles can have different surfaces to produce different shapes on vessels.

• Molding: Paste is molded onto some sort of template, allows for mass production of identical items/vessels.

• Wheel Turned: Not known in North America but common in the old world.

  • Paste is "thrown" on a rotating wheel and is built or massaged into shape.

Surface Treatment:

• Surface Treatment: Plain, Cord marked, Stamped, Corrugated, Smoothed, Brushed.

• Slips: A watery clay wash, not a pigment, that is usually applied over the entire vessel by dipping the pot into it or brushing it on.

Paints:

• Paints: Fugitive, Non-fugitive, Negative.

  • Fugitive paints: Must be applied after firing or they would be burned off during firing (vegetable pigments).

  • Non-fugitive paints: Applied before firing and generally change color with firing (mineral pigments).

  • Negative painting: Pot is coated in some sort of sticky substance, a design is scratched in it and fired

  • Exposed area is oxidized, and covered area is reduced.

Firing:

• Firing: Heating to bind the paste, usually at 600 - 800 C.

  • Oxidized Environment (open fire): Produces red, yellow, brown, and orange colored ceramics.

  • Reduced Environment (kilns): Produces grey, black, and white colored ceramics.

  • Kilns: Ovens, generate higher heats than open fires

Sherds:

• Sherds: Fragments of pottery.

  • Areas of vessel they came from (top to bottom): Rim, Neck, Shoulder, Body, Base.

Residue:

• Residue: Leftover contents of pot.

Ceramic Technology: Steps of Manufacture

• Steps of ceramic manufacture: Shaping, Drying, Firing.

Seriation

• The success of early pottery went extinct like the Dodo Bird, Seriation can be used to tell time
• Seriation will place items in a series so that the position of each item best reflects the degree of its similarity with all the other items in the set.

Seriation Types:

• Evolutionary Seriation: Order items in a sequence based on a simple universal rule and the direction and order of development is derived from the rule (Ex: simple to complex).

• Similary Seriation: Based on similarity alone and not based on a rule of development

  • Tracks gradual changes in shape, form, color etc.

Similary Seriation: Categories

• Similary Seriation: Categories: Phyletic, Occurrence, Frequency.

  • Phyletic Seriation: Chronological ordering of objects based on similarity in appearance.

  • Occurrence: Records the presence or absence of specific artifact types.

  • Frequency: Artifacts are chronologically ordered by ranking relative frequencies of appearance.

Seriation: Assumptions

• Assumptions to be met for seriation:
  • Culture change is gradual and continuous
  • Heritable continuity which requires assemblages from the same cultural tradition and local area
  • Requires assemblages to be of comparable duration

Dating Methods

• Relative Dating: Determining the order of an event relative to another, using stratigraphy or seriation.

  • Superposition: What is at the bottom is older than what is at the top.

• Absolute/Chronometric Dating: Provides an actual date, including dendrochronology, radiocarbon dating, potassium-argon dating, thermoluminescence, and obsidian hydration.

Radiocarbon Dating (C14):

• Most widely used method of absolute dating.

  • Developed by Libby in late 1940s, comes out of nuclear development for atomic weapons.

  • Willard F. Libby: Developed radiocarbon dating.

  • Neutrons: A neutral particle.

  • Beta particles: Half-life involves decaying, meaning they are being emitted constantly.

  • Half-life (5730 +/- 40 years): Current best estimate of a C-14 half-life.

  • Radiocarbon years: Indirect, and events are assigned dates by association.

  • Calendar years: Official dating like AB/BC, ADE/BCE, etc.

  • Standard deviation: Dated material is presented with an error range of ±1.

    • Dateable materials: Charcoal, wood, twigs, and seeds (plant material), Bone, antler, horn, Shell, Coprolites, Rock art, paint, some pottery, Textiles, Metal Casting Ores, Hair, Pollen, Ice cores, Paper, Peat, Blood Residue.

  • Effective range: 150k to 40k years ago.

  • AMS: Accelerator Mass Spectroscopy: New method that directly counts C14 atoms, uses less material, dates to 50k years ago.

  • More accurate, but expensive.

Obsidian Hydration:

• The rate of obsidian hydration is controlled by Temperature, Humidity, Chemical composition of obsidian
• Primarily used in California
• Measures the last time a flake was removed from the surface of an obsidian object.

  • A direct-dating method because it is based on objects themselves.

  • Can be used as both a relative and absolute dating method.

  • Hydration Layer: The thicker it is, the older the object is.

    • Can be used to detect recycling and resharpening, to detect mixing of deposits in sites, and as an absolute dating method.

Thermoluminescence (TL):

• Used to date baked prehistoric materials such as clay vessels or materials exposed to light.
  • Pottery is heated until a visible light is emitted.
  • 30% error rate.

Potassium-Argon Dating:

• Works on the principle of radiocarbon decay.
  • Used to date volcanic rock.
  • Counts decay of 40Ar to 40K.
  • Dates 4-5 billion to 100k years.

Human Environment and Ecology

• Human Environment: Every factor of humankind's surroundings which may affect (directly or indirectly) their mode of life and/or to which they might adapt.

• Ecology: The science of the interrelations between a particular set of living organisms and their environment.

• Paleoenvironment: Environment of the past.

  • Flora: Vegetation
  • Fauna: Animals
  • Coprolites: Fossilized poop
  • Geology: Geological processes reflect environment.
  • Isotopes: Matter is made up of different elements, some stable, others unstable.

Paleobotany and Zooarchaeology

• Paleobotany: The recovery and identification of plant remains from geological contexts.

  • Microbotanical plant remains (microscopic): Pollen, phytoliths, residue left in pots or on grinding stones.

  • Macrobotanical plant remains (macroscopic): Wood, seeds, tubers/roots, gourds.

• Zooarchaeology: The study of animal remains from archaeological sites

  • Taphonomy: The transformation of living organisms from the biosphere (living realm) to the lithosphere (geological realm).

Subsistence and Domestication

• Subsistence: Finding animal and plant remains in association with artifacts in archaeological sites.

  • Cultural Subsistence: Bone resulting from human behavior.

    • Good indicators: Burned, buried, broken, butchering marks, made into artifacts, used for house architecture.

  • Natural Subsistence: Bone in sites due to activity other than human

    • Animals can drag bone onto sites.

    • NISP: Number of Identified Specimens

    • MNI: Minimum Number of Individuals

    • MNE: Minimum Number of Elements

    • Seasonality: When during the year did activities take place?

      • Ways to determine seasonality involve Identifying seasonally available species and ontogenetic data

      • Ontogenetic data: Involves the study of growth and development of animals. Includes Epiphyseal fusion (bones), Tooth eruption sequences, and Tooth wear

        • Also dental annuli which are growth rings on animal teeth

    • Butchery/transport: How a carcass is cut up and taken from the kill locale to the camp locale.

      • Cut mark variables: Location, Orientation

      • Types of cut marks: Skinning, Filleting, Disarticulate

      • What butchering can tell you: Ethnicity, socioeconomic status.

• Domestication: Human modification of a plant or animal lineage producing an animal that is identifiably different from its wild ancestors and relatives

  • Genetic change through conscious or unconscious human selection.

  • Process of Domestication: Modification to behavior, osteological (bone) changes.

Biogeography and Trade

• Biogeography: Study of the distributions of plants and animals.

  • Comparing modern animal distributions to past distributions determined through archaeology and paleontology.

• Trade: An exchange of property involving interpersonal interaction between two or more parties (archaeologists interested in resource acquisition, stone).

  • Direct access to resources: Resource procured by the user at the natural primary source.

  • Indirect access to resources: Resource procured at the source by one group and then transferred via trade/exchange to other groups.

  • Distance decay: Start off with a lot of material near the source then as you move away you have less and less material.

  • Trace element analysis: Elements present in a mineral in minor proportions but can be characteristic of original source of material.

  • Neutron Activation Analysis: Takes a chemical "fingerprint" of the material being analyzed.

Human Diets

• Food Extractors: Foragers: A subsistence in which there is no concentration on any one resource and energy extraction is non-systematic (travelers)

  • This usually involves more search time and less processing time

• Food Extractors: Collectors: Systematic collection of plant and/or animal resources (processors).

  • This usually involves less search time and more processing time

Human Populations:

• Food Producers: Agriculturalists, Pastoralists.

  • Agriculturalists: Plant cultivators; larger populations, altered environment, tend to be sedentary.

  • Pastoralists: Graze animals; smaller populations, more mobile and often cover larger territories.

Laws

• Cultural Resource Management (CRM): Conservation archaeology.

  • Cultural resource: Everything made/moved by humans, cultural having more significance.

    • Unique and finite in number, preserve by evaluating historical significance.

  • UNESCO: United Nations Educational Scientific and Cultural Organization

  • Antiquities Act: Put into place by Teddy Roosevelt in 1906 to protect sites on federal land.

  • Reservoir Salvage Act: Last ditch effort in 1960s to have Secretary of the Interior to oversee salvage of resources in river basins flooded by dam construction.

  • National Historic Preservation Act: The most important law in 1966 which required the fed. gov. to est. a nationwide system for identifying and protecting cultural resources.

  • Archaeological and Historic Preservation Act: Amendment to the Reservoir Salvage Act in 1974 which finally provided FUNDING, up to 1% of fed. $ allocated to a project must be devoted to archaeological and historical resource mitigation.

  • NAGPRA: Native American Graves Protection and Repatriation Act in 1990 which provides protection for Native American marked and unmarked graves.

  • CRM: Culture Resource Management

CRM Responsibilities

-   **CRM Responsibilities: Archaeological Record**: Dig only if necessary, conserve as much as possible.

-   **CRM Responsibilities: Colleagues:** Don't smack talk, give credit

-   **CRM Responsibilities: Research and Scholarship:** Reports and publications must be reported, don't waste excavations, add to the knowledge pool

-   **CRM Responsibilities: Clients:** Be fair in terms of cost, time, results, and meeting deadlines

-   **CRM Responsibilities: The Law:** When completing contract, must follow law

-   **CRM Responsibilities: The Living:** Be responsible to all non-archaeologists including the descendants of those who made the sites