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GEOL exam 1
history of the earth
31
Geology
Undergraduate 1
02/11/2009

Additional Geology Flashcards

 


 

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Term
formation
Definition

mappable rock unit that is defined on the basis of lithology (phys, chem characterisitics od the rock)

NOT by age

Term
biostratigraphy
Definition
organization of strata/rock layers based upon their fossil content
Term
smith's 3 observtions
Definition

1. each rock unit had a characteristic, distinct assemblage of fossils

2. these same fossil assemblages could be recognized at other places

3. fossil assemblages occured in same sequence at different places

Term
principle of fossil succession
Definition
fossil assemblages succeed one another through time in regular, preditable order
Term
blankets
Definition
environ like floodplain and shallow marine shelves that cover large areas
Term
ribbons
Definition
long but thin environments (river, beaches)
Term
lenses
Definition
river channels
Term
large lobes/ fans
Definition
large triangular shapes due to sediment spreading out from one point- deltas, alluvial fans, deep sea turbidite fans
Term
load structure
Definition
graded bedding with flame structure
Term
graded bedding
Definition

course--> fine crystals found at turbidite environment

 

ex. lanslide/avalanche under water

Term
flute casts
Definition
form from erosional eddies in turbidite flow, and scour marks at base of the deposit that fill with sand when current loses velocity
Term
trace fossils
Definition
such as verticle burrows, reflect high energy conditions, horizontal ones are low energy setting
Term
meandering river
Definition
river that winds in gently sloping terrain, depositing sediment on the inside of each curve
Term
point bar
Definition
inside of bend where things are deposited
Term
floodplain
Definition
lowland area adjacent to the river where fine-grained sediments are deposited when the river overflows its banks
Term
marginal marine environments
Definition
delta
Term
delta plain
Definition
continental, undirectly cross bedded sands, coal, and freshwater to brackish fauna
Term
delta front
Definition
transitional
Term
pro delta
Definition
shallow marine
Term
inner delta plain
Definition
swamps yield thick coals and shales with nonmarine fossils.
Term
outer delta plain
Definition
shales with brackish water fossils, saltwater swamps
Term
facies of delta plain depositional environ
Definition

coals

lenses of sandstone 

shales

Term
barrier island
Definition
elongated island that parrels the coastline and is composed mostly of sand piled up by waves and longshore currents
Term
lagoons
Definition
lie btwn barrier islands and mainland, fine grained sediment
Term
tidal flats
Definition
nearly flat coastal area formed by mud
Term
marshes
Definition
above tidal flats where plans grow and plant debris build up
Term
reef flat
Definition
horizontal upper surface of the roof (near sea level)
Term
talus
Definition
pile of rubble that slopes seaward from reef front
Term
atoll
Definition
circular or horseshoe-shaped reef growing on submerged volcanoe
Term
big steps in fossil formation
Definition

death

decomposition/decay

rapid burial

Term
diagenesis
Definition

any chem, phys, biological change undergone by sed/organism after its initial decomposition(death)

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