CENPHYS

Cenozoic History : 

At only 66 million years long, the Cenozoic is only 1.4% of all geologic time only 20 minutes on a 24-hour clock Cenozoic History

Cenozoic Time Scale: 

In this class we use the term Tertiary Period rather than Paleogene and Neogene Periods Cenozoic Time Scale

Cenozoic Plate Tectonics: 

By Eocene time, the Americas had completely separated from Europe and Africa but India had not yet collided with Eurasia Cenozoic Plate Tectonics

Cenozoic Plate Tectonics: 

During Miocene time, the Atlantic Ocean basin continued to widen and India had collided with Eurasia The Tethys Sea between Africa and Eurasia was mostly closed by this time Cenozoic Plate Tectonics

Age of Ocean Basins: 

Age of Ocean Basins

Orogenic Belts: 

Alpine-Himalayan orogenic belt and the Circum-Pacific orogenic belt are the sites of most recent geologic and orogenic activity Orogenic Belts

Cenozoic Plate Tectonics: 

Eocene time Cenozoic Plate Tectonics

Cenozoic Plate Tectonics: 

Miocene time Cenozoic Plate Tectonics

The Himalayas—Roof of the World: 

During the Early Cretaceous, India broke away from Gondwana and began moving north oceanic lithosphere was consumed at a subduction zone along the southern margin of Asia The Himalayas— Roof of the World

Before India Collided with Asia: 

Oceanic lithosphere subducted beneath southern Tibet as India approached Asia northern margin of India Before India Collided with Asia southern margin of Tibet

India Collided with Asia: 

About 40 to 50 million years ago, India collided with Asia but because India was to light to subduct, it thrust under Asia India Collided with Asia

Continued Convergence: 

Thrusting of Asian rocks onto the Indian subcontinent accompanied continued convergence Continued Convergence

India Moved beneath Asia: 

Since about 10 million years ago, India has moved beneath Asia along the main boundary fault India Moved beneath Asia Shallow marine sedimentary rocks that were deposited along India’s northern margin now form the higher parts of the Himalayas

The Circum-Pacific Orogenic Belt: 

The Circum-Pacific Orogenic Belt

Evolution of the Andes Mountains : 

Prior to 200 million years ago, the west coast of South America was a passive continental margin huge quantities of sediment were deposited Evolution of the Andes Mountains

Evolution of the Andes Mountains : 

Orogeny began when this area became an active continental margin as South America moved to the west and collided with oceanic lithosphere Evolution of the Andes Mountains

Evolution of the Andes Mountains : 

Deformation, volcanism and plutonism continued Evolution of the Andes Mountains

The North American Cordillera: 

The North American Cordillera is one large segment of the circum-Pacific orogenic belt extending from Alaska to central Mexico In the United States it widens to 1200 km stretching east-west from the eastern flank of the Rocky Mountains to the Pacific Ocean The North American Cordillera

Cordillera: 

Cordillera

Plate Interactions Continue: 

Plate Interactions Continue http://earth.geol.ksu.edu/sgao/research/data/seiswus/example1.gif

The Laramide Orogeny: 

Third in a series of deformational events in the Cordillera beginning during the Late Jurassic Late Cretaceous to Eocene Differed from the previous orogenies in important ways The Laramide Orogeny

Laramide orogeny: 

Farallon plate, buoyed up by a mantle plume, subducted beneath North America at a decreasing angle igneous activity shifted inland Laramide orogeny ???

Igneous Activity Ceased: 

With nearly horizontal subduction, igneous activity ceased continental crust was deformed mostly by vertical uplift Igneous Activity Ceased

Tertiary Volcanism: 

Tertiary Volcanism more or less continuous in the Cordillera varied in intensity, eruptive style, and location ceased temporarily in the area of the Laramide orogen

Columbia River Basalts: 

an aggregate thickness of about 2500 m well exposed in the walls of the deep gorges cut by the Columbia and Snake rivers Some of the individual flows were truly phenomenal Roza flow alone covers 40,000 km2 and has been traced about 300 km from its source Columbia River Basalts ~ 20 lava flows of the Columbia River basalts exposed in the canyon of the Grand Ronde River in Washington

Cascade Range: 

Some of the highest mountains in the Cordillera are the Cascades California, Oregon, Washington, British Columbia Thousands of volcanic vents are present dozen large volcanoes Lassen Peak in California world's largest lava dome Related to subduction of the Juan de Fuca plate Cascade Range http://www.cr.nps.gov/history/online_books/resedu/resedu2a.htm

Basin and Range: 

Basin and Range

Basin and Range Province: 

Generalized cross section of the Basin and Range Province ranges are bounded by faults Basin and Range Province

Pacific Coast: 

Before the Eocene, the entire Pacific Coast was a convergent plate boundary Farallon plate was consumed at a subduction zone stretched from Mexico to Alaska Pacific Coast

Change from Subduction: 

As the North American Plate overrode the Pacific–Farallon Ridge, its margin became transform faults the San Andreas and the Queen Charlotte alternating with subduction zones Change from Subduction

Extending the San Andreas Fault: 

Further overriding of the ridge extended the San Andreas Fault and diminished the size of the Farallon–Plate remnants Now only two small remnants of the Farallon plate exist the Juan de Fuca and Cocos plates Extending the San Andreas Fault

Cenozoic History of the Appalachian Mountains: 

Deformation in the Appalachians has a long history began during the Late Proterozoic Cenozoic History of the Appalachian Mountains during Late Triassic time, the entire region experienced faulting as Pangaea fragmented

Reduced to Plains: 

By the end of the Mesozoic erosion had reduced the mountains to a plain across which streams flowed eastward to the ocean Reduced to Plains

Appalachians in the Tertiary: 

Streams developed across the plains during the Tertiary Appalachians in the Tertiary

Present Appalachian Topography: 

Although these mountains have a long history their present topographic expression resulted mainly from Cenozoic uplift and erosion Present Appalachian Topography

Slide36: 

The Atlantic Coastal Plain and the Gulf Coastal Plain form a continuous belt from the Northeastern United States to Texas The Southern and Eastern Continental Margins

Coastal Plain Similarities: 

Both areas have horizontal or gently seaward-dipping strata deposited mostly by streams flowing across them Seaward of the coastal plains lie the continental shelf, slope and rise, also areas of notable Mesozoic and Cenozoic deposition Coastal Plain Similarities http://www.missgeo.com/directors%20-%20mail.htm

Gulf Coast Sedimentation Pattern: 

The overall Gulf Coast sedimentation pattern was established during the Jurassic and persists today Sediments derived from Cordillera western Appalachians Interior Lowlands were transported toward the Gulf of Mexico where they were deposited in terrestrial, transitional, and marine environments Gulf Coast Sedimentation Pattern

Gulf-Coastal-Plain Deposition : 

Cenozoic Deposition on the Gulf Coastal Plain Gulf-Coastal-Plain Deposition Depositional provinces and surface geology Cross section of Eocene Claiborne Group Showing facies changes and seaward thickening

Reservoirs for Hydrocarbons: 

Many sedimentary rocks in the Gulf Coastal Plain are either source rocks or reservoirs for hydrocarbons Reservoirs for Hydrocarbons http://www.spe.org/specma/binary/images/1257473world_oil_production.gif

Oil and Gas Activity!: 

Oil and Gas Activity!