archaeology 2

relative dating

chronologic order

chronometric (absolute dating)

interval dating back from the present, exact years

relative dating methods

3 Age System, Direct Historical Approach

seriation dating

ordering objects through time

two kinds of seriation

context and frequency

cross dating

use of trade objects (or other mobile entities) as time markers between distant findspots

terminus ante quem (TAQ)

deposition must be before a certain time marker

 terminus post quem (TPQ)

 deposition must be after a certain time marker

physio-chemical techinques

obsidian hydration, dendrochronology, geochronology

obsidian hydration

 measuring the hydration rinds of freshly broken obsidian tools and debitage

dendrochronology

tree-ring dating by coring modern and ancient logs

geochronology

dating based on comparison of earth layers and their contents

pollen profiles, paleofauna, lithology, etc.

chronometric dating methods

isotopic decay, induced energy build up by radioactivity, layer techniques, chemical infiltration, miscellaneous (sidreal, archaeomagnetism, amino acid racemization)

kinds of isotropic decay

radiocarbon (¹⁴C), potassium-argon (K/Ar), uranium-thorium (U-Th)

Induced energy buildup by radioactivity

thermoluminescence (TL), optically stimulated luminescence (OSL), electron-spin resonance (ESR), fission track

layer techniques

dendrochronology, varves

chemical infiltration

obsidian hydration, fluorine dating

geomagnetic pole

 surficial points at the ends of a straight line linking the N and S poles and passing through Earth’s center that best correlates with the planet’s magnetic field

magnetic pole

surficial points at the ends of a straight line linking the N and S poles but not passing through Earth’s center

most widely used chronometric

radiocarbon

survey

systematic attempt to locate, identify, and record distribution of archeological sites on the ground in relation to their natural environment

Site assessment

evaluation o each site’s archaeological significance; considers site location and evaluates data from controlled surface collections and in some cases information from subsurface detection

excavation

intensive digging of the site

how sites are discovered

field walking, chance discovery, historical records and oral traditions, reconnaissance survey, intensive survey

remote sensing discovery methods (plane and satellite)

shadow sites, crop and soil marks, imaging in visible light and IR (infrared), side-scan radar, liDAR (light detection and ranging)

shadow sites

caused by slight variations in topography; rising or setting sun can set off long shadows, emphasizing the relief of almost-vanished banks or ditches

crop and soil marks

visual patterns of topography created by variation in crop growth and the exposure of distinctive soil types indicative of archeological features, seen in aerial photographs

imagining in Infrared

infrared film has three layers sensitized to green, red, and infrared; detects reflected solar radiation invisible to the human eye

side-scan radar

works like echolocation, can penetrate tree canopies for imaging info

LiDAR (light detection and ranging)

improvement on side-scan, measures up to 100,000 point per second, laser can get multiple layers of images from planes to create 3D digital models

remote sensing techniques (non intrusive, subsurface)

bowsing, electrical resistivity, magnetometry, ground-penetrating radar, metal detectors (problematic)

bowsing

surface of site is thumped with a heavy pounder; earth resonates so that a practiced ear can detect distinctive sound of a buried ditch or subsurface stone wall

resistivity survey

electrical resistivity of soil provides clues to subsurface features; measured with a resistivity meter

magnetometry

variation in magnetic fields used to find buried features

ground-penetrating radar

reflects radar waves off subsurface features by propagating pulses of radar waves from surface antenna

resistivity principle

Electricity can pass through finer soil like clays/silts than coarser materials like sand because the greater water content of loamier soils conducts better

metal detector principle

electrical field generated by instrument coil induces a current in the buried metal object which completes an electrical circuit and sounds a signal

organizing excavations requires

multidisciplinary teams, excavation staff, research design and funding, tools (pointing trowel)

CRM

cultural resource management

Site Supervisors

skilled excavators responsible for excavating trenches and recording specific locations

recording experts

artists and photographers; were take thousands of digital images, slides, and black and white photographs and create a complete record of excavation; use photography, hand-drawn recording, and electronic devices and programs (CAD)

Laboratory Staff

bag, wash, and rough-sort finds and mark them for transport to labs

foremen

manage paid laborers

CRM Staff

identify, assess, preserve, and manage cultural or archaeological resources

excavation techniques

vertical excavation , horizontal excavation, grid trenching, datum measurement (3D recording), step trenching, sections (baulks) and profiles, recording, conservation of fragile finds

recording

notebooks, photos, site plans, section profiles, now digital recording

vertical excavation

selective excavation; used to establish stratigraphic sequences

horizontal excavation

area excavation; closer to total excavation; larger scale

test pitting

small trenches just large enough for 2 diggers

step trenching

a trench cut in a series of steps from the base to the top of a mound for determining the cultural levels of an archaeological site

sampling objective

to obtain a representative sample of the total target population

when sampling_____

One cannot survey or excavate everything; for large sites maybe less than 1%

One must leave some part of a site unexcavated to await future research using updated methods

Two major kinds of sampling

judgmental and probabilistic

judgmental sampling

non-random, subjective choice; excavating the acropolis or fortifications of a site because it will contain remains of interest

probabilistic sampling

andom selection of survey or excavation units to distribute the chance of discovery over the total area; removes bias in choice of sample units; still does not guarantee representativeness, but eliminates unconscious bias

simple random

draw sample units from hat

systematic

excavate every nth unit in pre-established grid

stratified

 divide total area into areas having particular characteristics, then sample within each: upper town vs lower town of a large site different ecozones in a large survey area (highland, valley, marshes, foothills, etc.)

classification reasons

 organize data into manageable units; isolate and describe types; study interrelationships; document assemblage variability

taxonomy

naming and grouping entities to create order

systematics

study of the variation in types to understand their relationship

classifications are _____

heuristic

ideally classifications are_____

in the order intended by the ancient makers

types

statistically meaningful forms that represent most commonly recovered objects

attributes

minimal unite of description; one of several states of a mode

mode

set of attributes describing one aspect of an artifact

type

statistically clustered attributes thar give non-random grouping that describe particular and repetitive forms; recurrence of patterns

types can be

descriptive (morphology based), chronological (time-based), function (use-related), and stylistic (based on variant details with presumed cultural significance)

Spaulding

argued statistics analyzed by computers can yield inferences about intent regarding artifacts

Ford

statistics cannot prove intent in analysis; all you can do is form groups that serve as types

X² (chi-square) test

for statistical randomness in Spaulding’s research; beginning of quantitative applications in archeology

quantitative methods

allow archeologists to control large amounts of data effectively

descriptive stats

describe the numbers and kinds of artifacts, their range of variation, frequency in each layer, etc.  Used for comparison to other site

Inferential (confirmatory) stats

 permit archaeologist to make calculated estimates that refer to the total population from which the studied sample was drawn; depends on the sample studied being representative of the target population.

lithics

reductive technology; stone tools produced by subtractive process called knapping

core

lump of stone used to create lithics by the removing of a series of flakes

conchoidal fracture

a fracture with smooth, curved surfaces, typically slightly concave created by force

bulb of percussion

the primary feature that identifies the ventral surface of a flake or blade artifact

how to study lithics

core refitting to reconstruct the reduction sequence; use wear analysis

process of creating ceramics

-clay choice, mixing, preparation (weathering, levigation, tempering

-molding, coil building, tournette and wheel

-surface treatment: slip, texturing, paint, glazing

-firing in kiln or hearth

analytical techniques to study ceramics

petrography, compositional analysis, residue analysis, experimental archology

metals are attractive as tool material because

malleable, durable, can be remelted for recycling (creates preservation problems)

copper and gold

earliest metal use; casting technologies; alloys of arsenical copper and bronze

electrum iron

later forging technology; alloying with carbon to make steel

textiles

Rarely preserved; matting sometimes recognizable as impressions in floor materials, weave patterns, reconstruction of looms and yarn production (spindle whorls)

geoarchaeology

subsumes many of the fields contributing to the goals of environmental analysis; includes use of earth science methods and knowledge to solve archeological questions

Geochemical, electromagnetic, and other remote sensing methods are used to

-to locate sites and places with cultural remains or relevant natural features

-identify site formation processes

landscape reconstruction is done by

 using geomorphology, sediment analysis, biological evidence within sediment layers (e.g., pollen), and artificial disturbances to natural processes

dating methods (relative and chronometric) are based on

physical and geochemical processes

geochemical sourcing of artifact materials based on trace minerals is useful for

lithics, ceramics, precious minerals (turquoise, lapis lazuli), building stone, and metals

specialized analysis

heat treatment of flints, industries producing metals, glass, concrete, pigments

diagenesis

alterations to artifacts by burial, oxidation in air, human modification, etc.

paleodiet

info on ancient diet based on bone ratios of trace elements or stable isotopes of nitrogen, carbon, sulfur, hydrogen, and oxygen

how many known ice ages

five

most recent and ice age, important for humans

Pleistocene (1.8 mya to 10,500 ya) 

comprised several ice sheet advances out of the arctic and high elevations

Holocene (10,500 ya to present)

represents the current phase of glacial retreat (interglacial)

glacial advance is at final stage where

eastern US

periglacial

conditions near ice sheets

isostasy

depression and rebounding of earth’s crust under loading by ice sheets

Loess

glacial silt, eolian deposition from glacial outwash

Holocene climatic reconstruction is done by

pollen analysis and dendrochronology