Geology Ch 15
Terms
undefined, object
copy deck
- possible cause for the eastward migration of igneous activity in the Cordilleran region during the Cretaceous was a change from
- high-single to low-angle subduction
- aulacogen
- sediment-filled, inactive rift of a triple junction that formed above a rising mantle plume
- during the Jurrasic, as major evaporite accumulation occured, what happed between North American and South America
- North American rifted from South America
- Sierra Nevada, Southern California, Idaho, and Coast Range batholiths formed as a result of which orogeny
- Nevadan
- more than 25% of the North American western margin originated from
- the accretion of microplates
- the four interrelated orogenies of Western North America
- Sonoma, Nevadan, Sevier, and Laramide
- Gulf Coastal region was the site of what during the Jurrasic
- major evaporite accumulation
- Sonoma orogeny
- Permian-Triassic orogeny caused by the collision of an island arc with the southwestern margin of North America
- first Mesozoic orogeny in the Cordilleran region
- Sonoma
- cratonic sequence deposited during Early Jurassic to Early Paleocene
- Zuni
- Eastern Coastal Plain was the initial site of
- the separation of North America from Africa that began during the Late Triassic
- microplate
- small lithospheric plate
- cause of the Sonoma, Nevadan , Sevier, and Laramide orogenies was
- the changing angle of subduction of the oceanic Pacific plate under the continental North American plate.
- breakup of Pangaea influenced
- global climatic and atmospheric circulation patterns
- orogeny responsible for the present-day Rocky Mountain
- Laramide
- age of the thick evaporite deposits of the Gulf Coastal region that form the Tertiary salt domes
- Jurassic
- During the Cretaceous, the Gulf Coastal region was inundated by
- a transgressing sea, which, at its maximum, connected with a sea transgressing from the north to create the Cretaceous Interior Seaway
- consists of a chaotic mixture of rocks brought together in a submarine trench when North America overrode the subducting Pacific oceanic plate
- Franciscan Group
- one of the major controls of sediment distribution patterns during the Mesozoic
- tectonism
- Jurassic formation or group famous for dinosaur fossils is the
- Morrison
- Sevier orogeny
- Cretaceous phase of the Cordilleran orogeny that affected the continental shelf and slope areas of the Cordilleran mobile belt
- failed rift of a triple junction
- aulacogen
- during the breakup of Pangaea, overall global temperatures
- remained equable
- Nevadan orogeny
- Late Jurassic to Cretaceous phase of the Cordilleran orogeny; most strongly affected the western part of the Cordilleran mobile belt
- Cretaceaous Interior Seaway
- interior seaway that existed during the Late Cretaceous; formed as northward-transgressing waters from the Gulf of Mexico joined with southward-transgressing water from the Arctic; effectively divided North America into two large landmasses
- second stage of the breakup of Pangaea
- involved the separation of Antarctica, India, and Australia from South America and Aftica during the Jurassic. India broke away from the still-united Antarctica and Australia landmass
- explains the structural features of the western margin of North America
- orogenic activity associated with the oceanic-continental convergent plate boundary in the Cordilleran mobile belt
- first stage of the breakup of Pangaea
- involved the separation of North America from Africa during the Late Triassic, followed by the separation of North America from South America
- time of greatest post-Paleozoic inundation of the craton occurred during
- Cretaceous
- filled the Eastern Coastal region Triassic fault-block basins
- Newark Group
- Zuni sequence
- Early Jurassic to Early Paleocene sequence of sedimentary rocks bounded above and below by unconformities; deposited during a transgressive-regressive cycle of the Zuni Sea
- increased rate of seafloor spreading during the Cretaceous Period caused
- sea level to rise and transgressions to occur
- during Pangaea's breakup, the temperature gradient
- increased from the tropics to the poles during the Mesozoic
- third stage of the breakup of Pangaea
- South America separated from Africa, while Europe and Africa began to converge
- Sundance Sea
- wide seaway that existed in western North America during the Middle Jurassic Period
- first major seaway to flood North America was
- Sundance
- responsible for the spectacular scenery of the Painted Desert and Petrified Forest
- Chinle Formation
- Cordilleran orogeny
- protracted episode of deformation effecting the westerm margin of North America from Jurassic to Early Cenozoic time; typically divided into three separate phases called the Nevadan, Sevier, and Laramide orogenies
- triple junction
- point where three plates meet, e.g., the triple junction formed at the intersection of the East African Rift System and the rifts in the Red Sea and Gulf of Aden
- during the Cretaceous Period, the Eastern Coastal Plain was inundated by
- marine transgressions
- breakup of Pangaea began with initial Triassic rifting between which two continental landmasses
- Laurasia and Gondwana
- each of the Western North American orogenies involved
- batholithic intrusions as well as eastward thrust faulting and folding
- Laramide orogeny
- Late Cretaceous to Early Cenozoic phase of the Cordilleran orogeny; responible for many of the strctural features of the present-day Rocky Mountains. In contrast to the preceding Nevadan and Sevier orogenies, the Laramide orogeny deformed the margin of the craton
- type of climates which dominated the Triassic low and middle latitudes
- warm and dry
- which group of invertebrates were the main constituents of many of the extensive Cretaceous carbonate reefs
- rudists
- last stage of the breakup of Pangaea
- Greenland separated from North America and Europe
- was related to seafloor spreading and the opening of the Atlantic ocean
- timing, rate, and to some degree the direction of plate movement
- Mesozoic rocks of the western region of North America were deposited
- in a variety of continental and marine environments
- Mesozoic tectonic history of the North American Cordilleran region is very complex and involves
- oceanic-continental convergence and microplate accretion
- evidence for the breakup of Pangaea
- rift valleys, dikes, sills, great quantities of poorly sorted nonmarine detrital sediments
- except for incursions along the continental margin and two major transgressions (the Sundance Sea and the Cretaceous Interior Seaway), the North American craton was
- above sea level during the Mesozoic Era