Chapter 6 Flashcards
To asses previous enviromental conditions
look at them globally
Sediment of ocean floors accumulates
very slowly
Can trace changes in enviroment through time by studying
o Cores taken from the sea bed
o Fluctuations in the species
Morphology of single species through the sequence
Oxygen isotope technique
Cores come from stratified sheets of ice where the oxygen isotopic composition gives a guide to climate oscillations
Isostatic uplift/tectonic movement
the weight of ice is removed as the temp rise at the end of the ice age
WHY is the height of a raised beach above the present shoreline not always a straightforward indication of the former sea level height
o The land has been raised up through isostatic uplift
Raised beaches
- Location can be an indicator of earlier coastlines
Raised Beaches stratigraphy rather than vertical
can occur in horizontal stratigraphy rather than vertical
Coral reefs
Provides the position of previous shorelines and their organisms give info on local marine environment
Geoarchaeology
Area of study that uses methods and concepts of earth science to examine processes of earth formation and soil/sediment patterns
geoarchaeology aims
achieve the fullest possible reconstruction of the local area and set into the context of the region
Reconstruct glaciated landscapes is done through
varves, rivers and caves
VARVES
- Receive annual layers of sediment deposited after the spring thaw
Thick layers in varves
warm years with increased glacial melt
Thin layers in varves
cold conditions with less glacial melt
factors that affect varve readings
lakes that are
too shallow
have sediments that are easily disturbed
Form varves from other factors, violent storms
river show rapid change through
Erosion
Deposition of sediments
why are rivers important
often human occupation is close to a river and provided crucial rise of irrigation agriculture and urban civilization
Limestone caves
important because it can conserve a wide range of evidence about humans and the enviroment
The growth of tree rings varies with the climate
More moisture available = wider the annual rings
Growth was slow = which implies dense local forest cover
Growth was fast = which implies light forest cover
can record sudden and dramatic shocks to the climate
Tree rings
Sediments
the global term for material deposited on the earth’s surface
soils
the life-supporting, biologically and physically weathered upper layers of those sediments
Geomorphology
study of the form and development of the landscape
Sedimentology
the physical and chemical properties of sedimentary rocks and the processes involved in their formation
Two aspects combine to provide a detailed analysis of the composition and texture of sediments
o Petrography - detailed description of rock
o Granulometry - measurement of mineral rocks
Petrography
detailed description of rock
Granulometry
measurement of mineral rocks
Soil micromorphology
use of microscopic techniques to study the nature and organization of the components of soil
Karl Butzer
Distinguished three groups of cultural deposits
PRIMARY CULTURAL DEPOSIT
Those that accumulate on the surface from human activity
SECONDARY CULTURAL DEPOSIT
Primary deposits that have undergone modification
examples of secondary cultural deposit
Physical displacement
Change of use of the area
TERTIRAY CULTURAL DEPOSIT
- Those that have been completly removed from their original context
Plant studies are used to try and reconstruct
the vegetation that past people encountered at a particular time and place
Pollen analysis
can be applied to a wide range of sites and provides info on chronology and the enviroment
pollen gives ___________instead of _________
the idea of fluctuations in vegetation through time and an exact picture of past environments
Diatom analysis
· Diatoms are single-cell algae that have cell walls of silica instead of cellulose
what is important about silica
Silica cell walls survive after the algae die
Diatoms are used to identify
the period when lakes became isolated from the sea in areas of tectonic uplift
To locate the positions of past shorelines
Indicate marine transgressions
Reveal water pollution
Phytoliths
Minute particles of silica (plant opal) derived from the cells of plants and survive after the rest of the organism decomposes
where are phytoliths common
hearths and ash layers
why are phytoliths useful
o Produced in large numbers
o Survive well in ancient sediments
Have lots of distinctive shapes and sizes according to type
where do phytoliths survive
in sediments that are hostile to other preservation of fossil pollen
what can phytoliths inform us about
The use people made of particular plants
A simple presence that adds to the picture of the environment
phytoliths
Fossil cuticles
Cuticles are the outermost protective layer of skin (epidermis) of leaves or blades of grass
what are fossil cuticles made from
Made from cutin with different silica shapes and patterns
A useful complement to palynology where grass material, whole or fragmentary, needs to be identified
fossil cuticles
Rock varnishes are
natural accretions of manganese and iron oxides with clay minerals and organic matter
there is a strong correlation between _______ and their different local environments
relatively stable carbon isotopes
what provides information on changing conditions and the abundance of different plants
The ratios of these stable carbons found in the different layers of varnish on rock
first evidence used by archaeologists to characterize the climate of the prehistoric period
animal remains
different species were absent, present or abundant in certain layers would be
reflected in certain periods
Microfauna
Small animals that tend to be better indicators of climate and environmental changes than larger species
why are microfauna better at indicating climate changes
o They are more sensitive to small variations in climate
o Adapt better to them relatively quickly
what reflects the immediate environment
microfauna
what is an issue with larger animals
Animals killed by humans have been seen as prey and the bones cannot accurately reflect the full range of fauna present
Macrofauna is ideal when
animal remains brought by natural accident or catastrophe
why are macrofauna less reliable for climate changes
not so sensitive to environmental changes as smaller animals
why are microfauna more reliable than larger animals
They accumulate naturally on a site while larger animals often accumulated through human or animal predation
Paleofeces
- Ancient dung has survived in many dry caves - contains information about fauna and flora
what does ancient dung show
o Which animals were present in different periods
o What the animals ate
o Contributes to the debate on extinctions
what do findings in pale feces show about the New World extinctions
Findings suggest that the New World extinctions were not cased by changes in vegetation or diet
Big game extinctions compared across the world
· The big game extinctions in the New World and Australia at the end of the Ice Age had heavier losses than in Asia and Africa
where were climatic changes more important in the Big game extinctions
Northern Eurasia
where were human changes more important in the Big game extinctions
Americas
what were the two sides in the big game extinction debate
One side believed that the arrival of people in the New World and Australia with the overexploitation of prey led to the extinction
The other view is that climatic change is the primary cause of the extinction
what doesn’t the side of human interactions leading to the big game extinction account for
Does not account for the extinction at about the same time of mammal and bird species that were not obvious human prey
what doesn’t the side of climate interactions leading to the big game extinction account for
Does not account for why the many similar changes of earlier periods have a lesser effect on the animals
COMPROMISE THEORY
Believes that it was human overexploitation that first led to the disappearance of the mega-herbivores
This caused a change in vegetation that led to the extinction of some medium-sized herbivores
what were other theories about the big game extinction
- The impact of a comet about 13 000 years ago = the megafaunal extinctions
Lacking evidence that supports this theory - Hyperdisease theory
Lacks evidence that supports the idea of a single microbe being the reason dozens of unrelated species died
gardens
Can be either decorative or food-producing
what do casts of gardens show
o Provide details about gardening techniques
o Casts of plants that had been planted
Land management using field systems
The clearest evidence comprises the various traces visible on the land surface
what can also be a useful source of info about ancient land management
art and artifacts
pollution
not a modern phenomenon
water pollution
marked shifts from clean-water species to those that can survive in more polluted water
when did the water pollution change occur
Changed occured around the 10th century CE with the Viking town undergoing rapid development
air pollution
Lead levels first increased 5,500 years ago when farming increased wind-blown soils
examples of when the lead pollution increase
the Greeks began releasing lead into the atmosphere from extracting silver from oars
Romans with 80 000 tons of lead produced every from European mines
Reaves
bronze age stone boundary walls
Site Catchment Analysis
the examination by survey, excavation, maps, and graphs of a contained area to evaluate the productivity of the resources customarily exploited by the inhabitants of a settlement, especially a prehistoric one.
Site Exploitation Territory
the area around a particular site which would have been most intensively or frequently exploited for resources such as food.
Human Impact on Island Environments can be seen when
settlers introduce new animals and plants to the ecosystem
what is the impact of introducing new species to an island
would rapidly alter the islands irrevocably often through predation
what was a huge killer of island environments
habitat destruction
what has been shown about natural catastrophes
such as hurricanes and tidal waves have not affected vegetation
Easter Island
Enviromental damage is unique in both its extent and cultural/social consequences
what were the reasons for the destruction of Easter Island
o Transport the hundreds of giant statues across the island
o People ate the palm fruits
The Polynesian rats would have also been eating the fruit
what did the deforestation of Easter Island lead to
o Soil erosion
o Lower crop yields
o Starvation
Cultural decline
Pollen preservation in caves
Suitable because of their humidity and constant temp
Pollen preservation in dry sites
A series of separate samples can be removed from the sections
Pollen preservation is best in
acidic and poorly aerated peat bogs and lake beds
what does lime pollen show
transported by insects, is from trees that grow nearby
what does pine pollen show
transported by the wind, could be from hundreds of kilometers away
effects on pollen content
Orientation of sites
Location of sites
Length or type of occupation
where should pollen samples be taken
samples should be taken outside the site and within
what does pollen in peat bogs show
preserves pollen from a wider area
pollen found in soils away from human settlement shows
the local vegetation
Ecosystem
a community of living organisms that live and interact within a specific enviroment
Ecozone
distinct geographic area with specific groups of individuals living together
what are ecozones also known as
distinct biomes
ecotone
where two ecozones overlap, its the area of ecozone transition
paleoenvironment
past enviromental system
paleoclimate
past climate
climate
long term
weather
short term
Julian Steward
Defined cultural ecology or what’s now environmental archaeology
3 points made by Julian Steward
- cultures in similar environments have similar adaptive mechanisms
- all adaptions are short-lived and constantly changing
- changes alter existing cultures or make new ones
Karl Butzer
Human ecology
2 points about human ecology by Karl Butzer
- interactions between human and non-human communities are unavoidable
- equilibrium between human societies and the environment can never be reached
Michael Schiffer
formation processes
2 points of Michael Schiffer and formation processes
- there is a relationship between the cultural and natural formation processes
- creation of the archaeological record
how can the glacial environment be reconstructed
through the study of isotopes
In warm temps
see a shrinking of ice and glaciers - water is running back into the oceans - raising see levles
Colder climate temps
ice sheets hold more ice - water is not being replenished in the ocean - drop in sea level
18 000 years
Coldest climate in the glacial cycle
what happened 18 000 ya
Coast line being the furthest out to the sea - open land areas that would now be underwater
what is the Beringia
land mass that connected Siberia to North America through Alaska before being underwater
why are sea level fluctuations important
the humans are directly engaged in the enviroments
States that are topologically low
will become flooded and be underwater
high topographical features
not as much flooding
How is topography important for the reconstruction of the environment
need to reconstruct the original typography to see the past environment
Must locate these past coastlines - are they inland or underwater depending on the that time
many of Herod the heat’s monuments at Caesarea are now
under water due to coastal processes
but lots of Egypt will be under water because of the
rising sea levels
will Alexandria be underwater soon
YES
what did the major ice sheets do to the land
The glacier ice was moving and bulldozing the land as it expands and presses down on the land
what was the climate like in Canada during the last Ice Age
Canada was inhospitable during that last Ice Age because only a few lands were glacier free and able to be hospitable
As the glaciers bulldoze across the landscape
destroys anything on the surface
THE LACK OF EVIDENCE DOES NOT MEAN
THE SITE WAS NEVER THERE
Moraines
As the ice sheets bulldoze- lots of sediments build up
kinds of moraines
Lateral - the size of the moraines
The end - final end of the push
Based on the evidence what are the chances of sites being found in Canada prior to 16 000 ya
very little
Possible paths for the peopling of North America
- People travelled down the ice-free corridor (directly through Alberta)
- People travelled the Pacific Coast to the USA then to Canada
meandering river
the river has changed from its past morphology and location
types of geomorphology evidence
- glacial
- Alluvial (flowing water)
- Aeolian (wind)
- Lacustrine (standing water)
- Sping
- Coastal
- Slopes (mass wasting)
Sediments are the
erosion of particles
what helps keep erosion in check
vegetation
Soils development occurs in places
that have stability/ no erosion
what is the O-Horizon or Humus layer
the layer of soil that is made from the organic matter broken down by miroorganisms
soils are the
alteration of pre-existing sediments
soils can be considered the
in situ alteration of a pre-existing parent material
podzols
very acidic soils
what are podzols good for preservation and bad for preservation
bad- bones
good- pollen
what are podzolic good for preservation and bad for preservation
good- bones
bad - pollen
what level of the soil is the movement of iron
the B-Horizon
What kind of soil does Alberta have
not deep one that has developed over thousands of years
