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59 Cards in this Set

  • Front
  • Back
What is Catastrophism? and who proposed this?
This states that the earth's landscapes have been developed primarily by great catastrophe's. James Usher proposed this
What is Uniformitarianism? And who made the counter-proposal?
This states the physical, chemical and biological laws that operate today have also operated in geologic past. "the present is the key to the past"**
What can we determi ne within the geologic time?
the *relative* sequence of events.
but not the exact age.
very accurate.
Critical to the early understanding of geology
What were Nicolaus Steno's laws?
-Principle of Super position
-Principle of Original Horizontality
-Orinciple of Original lateral Continuity
-Principle of Cross-cutting Relationships
-Principle of Inclusions
what is the Principle of Origin Horizontally?
-(sedimentary) rocks on the bottom are older than the ones on the top.
-oldest sediments are deposited first
What is the Principle of Origin lateral continuity?
Sedimentary rocks generally acumulate in wide-spread, sheet-like deposits, thinning laterally.
What is the Principle of Cross-cutting Relationships?
faults and igneous intrusions are younger than the rocks they cut across.
What is the Principle of Inclusions?
Rock gragments caught up in igneous intrusions or in sedimentary rocks must have been there first.
What are unconformities? *memorize*
-a time-gap in the geologic record where there is not continuous depostion between the layers on top and the layers below.
What do unconformities indicate?
low sea level
What are the three kinds?
-angular uncomforties
What is an angular conformity?
an unconformity in which younger sediments rest upon the reoded surgace of tilted or folded older rocks
What is a disconformity?
an unconformity between beds that are parallel.
What is a nonconformity?
an unconformity between unstratified igneous rocks below and stratified generally sedimentary rcks above
What did william smith discover
that sequence of rocks were similar over great distances using fossils
What is the principle of Fossile Succession?
Fossil organisms succeed one another in a deinite and determinable order
what is an index fossil?
Unique and geographically widespread.
What are the different types of marker beds?
-Volcanic ash
-meteorite dust
-glacial till
-evaporite deposits
When was radioactivity discovered?
what is an isotope?
an element with several atomic weights due to differences in the number of neutrons in the nucleus.
what is a closed system involving isotopes?
mineral incorpoates only parent and no daughetr isotopes
What are the common isotopes?
Carbon and Nitrogen (younger)
Uranium and Theranium (older)
What are branded iron formations?
chert layers alternating with layers of irn-rich semdiment
what is life during Proterzoic eon?
stromatolites and multicelled animals
When was the rise of photosynthesus?
Proterozoic eon
What was land like in the proterzoic?
Supercontinent Rodinia
During the Cambrian period, what was happening to the continents?
They stood high above sea level as the rodinian supercontinent, This was also breaking apart.
What is transgression?
sea level rises
what is regression?
sea level falls
During the Permian period where were evaporites located?
during the equator
What was happening to the climate during the ordovician period?
glaciation was effecting sea level which leads to extinction
what was the life in the silurian period?
-Paleozoic reefs.
-First preserved fish!
-Spore plants expanded
What was te silurian climate?
-Climates were relatively warm and dry
-high sea level
What was happening to the plate tectonics during the Devonian period?
continued high sea levels.
What was devonian life?
-placoderms (crabs, lobster)
-ray-finned fishes (dominant fishes today
-lobed finned fishes - single boned fin
What was spreading during the Devonian Period?
Spread of forest's
During the devonian period there was global cooling which caused what?
Mass extinction
What was the dominant vertabrets into the Carboniferous?
What evolved late into the Carboniferous
Fixed wings
What land formation was being created in the Carboniferous period?
Appalachian Mountains
What was the climate like in the Permian period?
-Dry climates
-no coal swamps
-conifers instead
-evaporite near the equator
What was were amphibians becoming displaced by in the Permian period?
mammal-like reptiles and by fin-backed reptiled
What happened by the end of the Permian period?
A mass extinction totaling in 95% or all marine specied.
What was the plate textonix like in Triassic and Jurrassic periods?
Nealy all of the Earth's continental crust was together in another supercontinent PANGEA!
What happened because of Pangea?
land fossiles spanned all or most of the supercontinents
When did Pangea start to Rift?
Later in the Triassic
-opening Tethys
-then much later opening the Atlantic Ocean from South to North
-Sea level began to rise in the Jurassic
What was living within Mesozoic Oceans?
Invertebrate animals, mollsucs
what are gymnosperms?
Naked seed plants (pine cones)
at what period did mamls start to evolve?
what were a pterosaurs?
they are soaring reptiles
at what age did Dinosaurs dominate?
What happened in Cretaceous?
-Flower plants (angiosperms)
-Chalk (Creta)
-High sea level covered Texas, producing limestones
What coevolved with the dinosaurs during the Cretaceous?
During the Palogene and Neogene what happened to the continents?
-South American and Australia broke away from Antarctica
-Antarctica left isolated over the south poles
-Europe and Greenland were last to separate
Radiation of species adpated where during the Palogene and Neogene periods?
Drier climates
What are majoradaptive radiations/
frogs,rats,mice,songbirds,snakes,large gazing animals, apes.
What is Australopithecus?
oldest known genus of family hominidae, it evolved about 4 million years ago from apes, not monkeys!
What is homo?
the modern genus of the gamily homindae evolved about 2.5 million years ago.
When did hte modern ice age begin? and when did glaciers begin to retreat?
3.2 ma. 15,000 years.