Geology Exam Review
Terms
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- 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?
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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?
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-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?
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-(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?
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-angular uncomforties
-disconformities
-unconformities - 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?
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-Volcanic ash
-meteorite dust
-glacial till
-evaporite deposits - When was radioactivity discovered?
- 1896
- 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?
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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?
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-Paleozoic reefs.
-First preserved fish!
-Spore plants expanded - What was te silurian climate?
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-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?
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-placoderms (crabs, lobster)
-sharks
-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?
- Amphibians
- 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?
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-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?
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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?
- Triassic
- what were a pterosaurs?
- they are soaring reptiles
- at what age did Dinosaurs dominate?
- Triassic
- What happened in Cretaceous?
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-Flower plants (angiosperms)
-Chalk (Creta)
-High sea level covered Texas, producing limestones - What coevolved with the dinosaurs during the Cretaceous?
- Flowers
- During the Palogene and Neogene what happened to the continents?
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-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.