HOME
The Info List - North American Plate


--- Advertisement ---



The North American Plate
North American Plate
is a tectonic plate covering most of North America, Greenland, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland
Iceland
and the Azores. It extends eastward to the Mid-Atlantic Ridge
Mid-Atlantic Ridge
and westward to the Chersky Range
Chersky Range
in eastern Siberia. The plate includes both continental and oceanic crust. The interior of the main continental landmass includes an extensive granitic core called a craton. Along most of the edges of this craton are fragments of crustal material called terranes, accreted to the craton by tectonic actions over a long span of time. It is thought that much of North America
North America
west of the Rocky Mountains
Rocky Mountains
is composed of such terranes.

Contents

1 Boundaries 2 Hotspots 3 Plate motion 4 See also 5 References

Boundaries[edit] The southerly boundary with the Cocos Plate
Cocos Plate
to the west and the Caribbean Plate
Caribbean Plate
to the east is a transform fault, represented by the Swan Islands Transform Fault under the Caribbean Sea
Caribbean Sea
and the Motagua Fault through Guatemala. The parallel Septentrional and Enriquillo-Plantain Garden faults, which run through the island of Hispaniola
Hispaniola
and bound the Gonâve Microplate, are also a part of the boundary. The rest of the southerly margin which extends east to the Mid Atlantic Ridge and marks the boundary between the North American Plate and the South American Plate
South American Plate
is vague but located near the Fifteen-Twenty Fracture Zone around 16°N. On the northerly boundary is a continuation of the Mid-Atlantic ridge called the Gakkel Ridge. The rest of the boundary in the far northwestern part of the plate extends into Siberia. This boundary continues from the end of the Gakkel Ridge
Gakkel Ridge
as the Laptev Sea Rift, on to a transitional deformation zone in the Chersky Range, then the Ulakhan Fault between it and the Okhotsk Plate, and finally the Aleutian Trench
Aleutian Trench
to the end of the Queen Charlotte Fault
Queen Charlotte Fault
system. The westerly boundary is the Queen Charlotte Fault
Queen Charlotte Fault
running offshore along the coast of Alaska and the Cascadia subduction zone
Cascadia subduction zone
to the north, the San Andreas Fault
San Andreas Fault
through California, the East Pacific Rise in the Gulf of California, and the Middle America Trench
Middle America Trench
to the south. On its western edge, the Farallon Plate
Farallon Plate
has been subducting under the North American Plate
North American Plate
since the Jurassic
Jurassic
Period. The Farallon Plate
Farallon Plate
has almost completely subducted beneath the western portion of the North American Plate leaving that part of the North American Plate
North American Plate
in contact with the Pacific Plate
Pacific Plate
as the San Andreas Fault. The Juan de Fuca, Explorer, Gorda, Rivera, Cocos and Nazca plates are remnants of the Farallon Plate. The boundary along the Gulf of California
California
is complex. The Gulf is underlain by the Gulf of California
California
Rift Zone, a series of rift basins and transform fault segments between the northern end of the East Pacific Rise in the mouth of the gulf to the San Andreas Fault
San Andreas Fault
system in the vicinity of the Salton Trough rift/Brawley seismic zone.[2][3] It is generally accepted that a piece of the North American Plate
North American Plate
was broken off and transported north as the East Pacific Rise
East Pacific Rise
propagated northward, creating the Gulf of California. However, it is as yet unclear whether the oceanic crust east of the Rise and west of the mainland coast of Mexico is actually a new plate beginning to converge with the North American Plate, consistent with the standard model of rift zone spreading centers generally.[citation needed] Hotspots[edit] A few hotspots are thought to exist below the North American Plate. The most notable hotspots are the Yellowstone (Wyoming), Raton (New Mexico), and Anahim (British Columbia) hotspots. These are thought to be caused by a narrow stream of hot mantle convecting up from the Earth's core-mantle boundary called a mantle plume,[4] although some geologists think that upper-mantle convection is a more likely cause.[5][6] The Yellowstone and Anahim hotspots are thought to have first arrived during the Miocene
Miocene
period and are still geologically active, creating earthquakes and volcanoes. The Yellowstone hotspot
Yellowstone hotspot
is most notable for the Yellowstone Caldera
Yellowstone Caldera
and the many calderas that lie in the Snake River Plain
Snake River Plain
while the Anahim hotspot
Anahim hotspot
is most notable for the Anahim Volcanic Belt, currently found in the Nazko Cone
Nazko Cone
area. Plate motion[edit] For the most part, the North American Plate
North American Plate
moves in roughly a southwest direction away from the Mid-Atlantic Ridge. The motion of the plate cannot be driven by subduction as no part of the North American Plate
North American Plate
is being subducted, except for a small section comprising part of the Puerto Rico Trench; thus other mechanisms continue to be investigated. One recent study suggests that a mantle convective current is propelling the plate.[7] See also[edit]

Geologic timeline of Western North America New Madrid Seismic Zone
New Madrid Seismic Zone
- an ancient intraplate fault zone within the North American Plate, notable as early as 1699[8]

References[edit]

Notes

^ "Sizes of Tectonic or Lithospheric Plates". Geology.about.com. 2014-03-05. Retrieved 2016-01-11.  ^ USGS Professional Paper 1515 ^ USGS Farallon Plate
Farallon Plate
maps ^ "Hotspots": Mantle thermal plumes ^ Earth's interior: Raising hot spots ^ Upper-mantle origin of the Yellowstone hotspot ^ Seismic evidence for convection-driven motion of the North American plate, David W. Eaton & Andrew Frederiksen, Nature, March 22, 2007 ^ Feldman, Jay (2005). When the Mississippi Ran Backwards : Empire, Intrigue, Murder, and the New Madrid Earthquakes. Free Press. ISBN 0-7432-4278-5. 

v t e

Tectonic plates

Major

African Indo-Australian Plate Antarctic Eurasian North American Pacific South American

Minor

Amurian Arabian Caribbean Caroline Cocos Juan de Fuca Nazca Okhotsk Philippine Scotia Somali Yangtze

Other

Adriatic Aegean Sea Anatolian Australian Balmoral Reef Banda Sea Bird's Head Burma Capricorn Conway Reef Easter Explorer Futuna Galapagos Gonâve Gorda Greenland Halmahera Iberian Indian Iranian Juan Fernández Kerguelen Kermadec Madagascar Manus Maoke Mariana Molucca Sea New Hebrides Niuafo’ou North Andes North Bismarck North Galapagos Nubian Okinawa Panama Pelso Philippine Mobile Belt Rivera Sangihe Seychelles Shetland Solomon Sea South Bismarck South Sandwich Sunda Timor Tisza Tonga Woodlark

Historical

Baltic Bellingshausen Charcot Cimmeria Farallon Insular Intermontane Izanagi Kula Lhasa Malvinas Moa Phoenix

List

.