- Laramide orogeny
Series of mountain-building events that affected much of western North America in Late Cretaceous and Early Tertiary time (с 65 million years ago).The Laramide orogeny originally was believed to mark the Cretaceous-Tertiary boundary. It is now considered to have consisted of many separate pulses of deformation that varied in intensity and age from place to place. Laramide rocks, however, were generally created around the Cretaceous-Tertiary time boundary.
* * *▪ geologya series of mountain-building events that affected much of western North America in Late Cretaceous and Early Tertiary time. (The Cretaceous period ended 65.5 million years ago and was followed by the Tertiary period. In some geologic time scales the Tertiary is replaced by the Paleogene period and part of the Neogene period.) Evidence of the Laramide orogeny is present from Mexico to Alaska, but the main effects appear centred in the eastern portion of the Cordilleran Geosynclinefrom southern Nevada to the Northern Rockies and Northern Cordillera in western Canada, in the Central Rockies of Montana and Wyoming, in the Southern Rockies of Colorado and New Mexico, and in southern Arizona, southwestern New Mexico, and northern Mexico.The evidence consists of great eastward-directed thrust faults and folds with only slight basement involvement in the eastern portion of the Cordilleran Geosyncline from Nevada northward to British Columbia; initial vertical uplift accompanied by the development of flanking, coarse clastic basin sediments and unconformities in the Central and Southern Rockies; and acidic plutonic intrusions ranging from 50,000,000 to 70,000,000 years in age that are much smaller in bulk than those that accompanied the Nevadan orogeny, with the exception of the portion in southern Arizona.Clastic wedges that were derived from Laramide uplifts in the Cordilleran Geosyncline were shed eastward into parts of Wyoming and Utah.The Laramide orogeny originally was believed to mark the Cretaceous–Tertiary boundary. It is now considered to have been a polyphase orogeny consisting of many disparate pulses of deformation that varied in intensity and age from place to place in western North America. Events ascribed to the Laramide range in date from Late Cretaceous to as late as Oligocene time (the Oligocene epoch occurred from 33.9 to 23.03 million years ago). Laramide igneous intrusions, however, are generally centred around the Cretaceous-Tertiary time boundary.
* * *
Look at other dictionaries:
Laramide orogeny — The Laramide orogeny was a period of mountain building in western North America, which started in the Late Cretaceous, 70 to 80 million years ago, and ended 35 to 55 million years ago. The exact duration and ages of beginning and end of the… … Wikipedia
orogeny — orogenic /awr euh jen ik, or euh /, orogenetic, adj. /aw roj euh nee, oh roj /, n. Geol. the process of mountain making or upheaval. Also called orogenesis /awr euh jen euh sis, or euh /. [1885 90; ORO 1 + GENY] * * * I Mountain building event,… … Universalium
Orogeny — Geologic provinces of the world (USGS) Shield … Wikipedia
Sevier orogeny — The Sevier orogeny was a mountain building event that affected western North America from Canada to the north to Mexico to the south. This orogeny was the result of convergent boundary tectonism between approximately 140 million years (Ma) ago,… … Wikipedia
Nevadan orogeny — The Nevadan Orogeny was a major mountain building event that took place along the western edge of ancient North America between the Mid to Late Jurassic (between about 180 and 140 million years ago). The Nevadan orogeny was the first of three… … Wikipedia
Ларамийский орогенез — Ларамийский орогенез, ларамийская складчатость (англ. Laramide orogeny) горо … Википедия
Geology of the Grand Teton area — The geology of the Grand Teton area consists of some of the oldest rocks and one of the youngest mountain ranges in North America. The Teton Range, mostly located in Grand Teton National Park, started to grow some 9 million years ago. An older… … Wikipedia
North American Cordillera — The North American Cordillera is the North American portion of the American Cordillera which is a cordillera extending up and down the western side of the Americas. The North American Cordillera covers an extensive area of mountain ranges,… … Wikipedia
Geology of the Bryce Canyon area — Paria View overlooks an intermittent stream flowing toward the Paria River, s … Wikipedia
Geology of the Capitol Reef area — [ Waterpocket Fold is the major geographic feature in the area of the park. This view is from above Capitol Reef Scenic Drive looking back at the west face of the broken and eroded fold.] The exposed geology of the Capitol Reef area presents a… … Wikipedia