At only 66 million years long,

1
Cenozoic History

• At only 66 million years long,
• the Cenozoic is only 1.4 of all geologic time
• or only 20 minutes
• on our hypothetical 24-hour clock for geologic
  time

2
Cenozoic Time Scale

• In this class we use
• the term Tertiary Period
• rather than Paleogene and Neogene Periods

3
Late Cretaceous Rifts separate Africa and South
America and then India, Australia, Antarctica.
North America rifts from Europe. Old Gondwana
(Africa, India, Australia) move north toward
Eurasia, closing the Tethys Ocean and forming the
Alpine-Himalayan mountains. The Atlantic
lengthens / widens, the Sevier orogeny continues,
and the Caribbean arc forms. Texas 65-144 Ma
continuing shallow limestone and shale deposition
to the southeast (from Rockies).
http//vishnu.glg.nau.edu/rcb/globaltext.html
4
Paleocene / Eocene Himalayan Orogeny. Alps and
Pyrenees form. The modern patterns of geography
appear. Atlantic continues to open. Rocky
Mountains grow. Texas 65 - 35 Ma shale and
sandstone in southeast region prograde shoreline
(from the Rockies). Volcanic activity in
Panhandle.
http//vishnu.glg.nau.edu/rcb/globaltext.html
5
Cenozoic Plate Tectonics

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

6
Oligocene and Miocene Orogeny continues in the
Mediterranean region and India nears its junction
with southern Asia. Antarctica
isolated. Southwestern North America intercepts
the East Pacific Rise and a great extensional
event, the Basin and Range orogeny begins.
Texas 35-5 Ma continued sandstone/shale
deposition and progradation of shoreline (erosion
of Rockies)
http//vishnu.glg.nau.edu/rcb/globaltext.html
7
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

8
http//vishnu.glg.nau.edu/rcb/globaltext.html
9
Age of Ocean Basins
10
East African Rift

• A triple junction
• joins the East African Rift System
• to the Gulf of Aden
• and the Red Sea
• Oceanic crust began forming
• in the Gulf of Aden about 10 million years ago
• Red Sea rifting began later and oceanic crust is
  now forming

11
Orogenic Belts

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

12
Closure of the Tethys Sea

• Remember that during Mesozoic time
• the Tethys Sea separated much of Gondwana
• from Eurasia
• Closure of this sea
• took place during the Cenozoic
• as the African and Indian plates
• collided with the huge landmass to the north

13
Cenozoic Plate Tectonics

• Eocene time

14
Cenozoic Plate Tectonics

• Miocene time

15
The Himalayas

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

16
Before India Collided with Asia

• Oceanic lithosphere
• subducted beneath southern Tibet
• as India approached Asia
• northern margin of India

• southern margin of Tibet

17
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

18
Continued Convergence

• Thrusting of Asian rocks
• onto the Indian subcontinent
• accompanied continued convergence

19
India Moved beneath Asia

• Since about 10 million years ago,
• India has moved beneath Asia
• along the main boundary fault

• Shallow marine sedimentary rocks
• that were deposited along Indias northern
  margin
• now form the higher parts of the Himalayas

20
The Circum-Pacific Orogenic Belt
21
Evolution of the Andes Mountains

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

22
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

23
Evolution of the Andes Mountains

• Deformation, volcanism and plutonism continued

24
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

25
Cordillera

• North American Cordillera
• and the major provinces
• of the United States and Canada

26
Sedimentary Basins in the West

• Locations of Proterozoic sedimentary Basins
• in the western United States and Canada
• Belt Basin
• Uinta Basin
• Apache Basin

27
Cordilleran Mobile Belt
Antler Orogeny in Devonian
28
Cordillera Evolved

• After Laramide deformation, Cordillera continued
  to evolve
• large-scale block-faulting
• extensive volcanism
• vertical uplift and deep erosion
• Basin and Range
• During about the first half of the Cenozoic Era,
  a subduction zone was present
• along the entire western margin of the
  Cordillera,
• but now most of it is a transform plate boundary
• ???

29
Plate Interactions Continue

• http//earth.geol.ksu.edu/sgao/research/data/seisw
  us/example1.gif

30
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

31
Laramide orogeny

• took place as the Farallon plate,
• buoyed up by a mantle plume
• subducted beneath North America
• at a decreasing angle
• and igneous activity shifted inland

???
32
Change to Shallow Subduction

• By Early Tertiary time,
• the westward-moving North American plate
• had overridden the part of the Farallon plate,
• above the head of the mantle plume
• The lithosphere
• immediately above this plume
• was buoyed up,
• accounting for a change
• from steep to shallow subduction

33
Igneous Activity Ceased

• With nearly horizontal subduction,
• igneous activity ceased
• and the continental crust
• was deformed mostly by vertical uplift

34
Renewed Igneous Activity

• Disruption of the oceanic plate
• by the mantle plume
• marked the onset
• of renewed igneous activity

35
Cordilleran Igneous Activity

• The vast batholiths in
• Idaho
• British Columbia
• Sierra Nevada of California
• were emplaced during the Mesozoic Era
• intrusive activity continued into Tertiary

http//www.bhc.edu/academics/science/harwoodr/GEOL
102/Study/Images/BatholithsNA.gif
36
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

37
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

20 lava flows of the Columbia River basalts
exposed in the canyon of the Grand Ronde River in
Washington
38
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

http//www.cr.nps.gov/history/online_books/resedu/
resedu2a.htm
39
Basin and Range
40
Basin and Range Province

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

41
Colorado Plateau
42
Colorado Plateau

• Paleozoic rocks exposed in the Grand Canyon,
  Arizona

• Mesozoic sedimentary rocks in the Valley of the
  Gods, Utah

43
Colorado Plateau

• Mesozoic sedimentary rocks at Colorado National
  Monument, Colorado

44
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

45
Change from Subduction

• As the North American Plate
• overrode the PacificFarallon Ridge,
• its margin became transform faults
• the San Andreas
• and the Queen Charlotte
• alternating with subduction zones

46
Extending the San Andreas Fault

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

47
The Continental Interior

• A vast area called the Interior Lowlands
• the Great Plains
• and the Central Lowlands

48
Cenozoic History of the Appalachian Mountains

• Deformation in the Appalachians has a long
  history
• began during the Late Proterozoic

• during Late Triassic time, the entire region
  experienced faulting as Pangaea fragmented

49
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

50
Appalachians in the Tertiary

• Streams developed across the plains during the
  Tertiary

51
Present Appalachian Topography

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

52
The Southern and Eastern Continental Margins

• The Atlantic Coastal Plain and the Gulf Coastal
  Plain
• form a continuous belt
• from the Northeastern United States to Texas

53
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

http//www.missgeo.com/directors20-20mail.htm
54
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

55
Gulf-Coastal-Plain Deposition

• Cenozoic Deposition on the Gulf Coastal Plain

• Depositional provinces and surface geology

Showing facies changes and seaward thickening
Cross section of Eocene Claiborne Group
56
Reservoirs for Hydrocarbons

• Many sedimentary rocks in the Gulf Coastal Plain
• are either source rocks
• or reservoirs for hydrocarbons

http//www.spe.org/specma/binary/images/1257473wor
ld_oil_production.gif