Poking through the mass of some of the highest mountains in North America are very young volcanoes formed by the ongoing Pacific Plate subduction. 40 Million Years Ago Without referring to the plate map in Figure \(\PageIndex{1}\), or any other resources, write in the names of as many of the plates as you can. Feature labels. A divergent boundary occurs when two tectonic plates move away from each other. The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. Compaction in the Rock Cycle: Understanding the Process Behind Sedimentary Rock Formation, Crystallization in the Water Cycle: A Fundamental Process in Water Distribution and Purification, Understanding Crystallization in the Rock Cycle: A Fundamental Process in Rock Formation, Extracting Lat/Lng from Shapefile using OGR2OGR/GDAL. KEFJKenai Fjords National Park, Alaska[Geodiversity Atlas] [Park Home], CRLACrater Lake National Park, Oregon[Geodiversity Atlas] [Park Home], LAVOLassen Volcanic National Park, California[Geodiversity Atlas] [Park Home], MORAMount Rainier National Park, Washington[Geodiversity Atlas] [Park Home], ANIAAniakchak National Monument and Preserve, Alaska[Geodiversity Atlas] [Park Home], KATMKatmai National Park, Alaska[Geodiversity Atlas] [Park Home], LACLLake Clark National Park, Alaska[Geodiversity Atlas] [Park Home]. The North American plate is moving to the west-southwest at about 2.3 cm (~1 inch) per year driven by the spreading center that created the Atlantic Ocean, the Mid Atlantic Ridge. This plate includes India and the surrounding India Ocean. This plate is bound by the North-American and Caribbean Plates to the north-east, the small Rivera Plate to the north-west, the Pacific Plate to the west, Point Reyes National Seashore and Golden Gate National Recreation Area are the only two NPS sites that are right on the San Andreas Fault. That may not seem like much, but when tens of thousands of earthquakes occur over a few million years, coastal ranges form. We know that the JDF Plate is moving toward the North American Plate at around 4 centimeters per year to 5 centimeters per year. This is why some of the mountain chains formed during the earlier collision can be traced from Europe to North America and from Europe to Africa. Mazama 7,700 years before, the material expelled from its magma chamber did not spew forth out of the top of the volcano. An accretionary wedge forms between the converging plates as material is scraped off the subducting plate. Other rocks seen in the high mountains at the center of the park were pushed more deeply into the Earth, where increasing temperature and pressure changed them into metamorphic rocks known as quartzite and slate. Lassen Peak in Lassen Volcanic National Park is an amalgamation of rhyolite lava domes. Transform faults are not limited to oceanic crust and spreading centers; many of them are on continental margins. The major plates are Eurasia, Pacific, India, Australia, North America, South America, Africa, and Antarctic. National Park Service Sites in the Southern Alaska Subduction Zone reveal a variety of active volcanic features above the zone where the top of the Pacific Plate reaches sufficient depth where temperature and pressure are high enough to dehydrate rocks and form magma. And as time ticks on, the region awaits sudden release of energy locked between the converging plates as a devastating earthquake. Vents and fractures (also called fissures ) in these mid-ocean ridges allow magma and gases to escape into the ocean. The mountain is mainly andesite lava flows and volcanic mudflows covered by numerous glaciers. The Cascadia Subduction Zone and Southern Alaska are the sites of ongoing subduction as the Pacific and Juan de Fuca plates slide beneath the North American Plate. CC BY. Because the oceanic crust formed by spreading on the mid-Atlantic ridge is not currently being subducted (except in the Caribbean), the Atlantic Ocean is slowly getting bigger, and the Pacific Ocean is getting smaller. Expert Answer. Magmas high in silica are thick and pasty. St. Helens in 1980. What are the three types of convergent plate boundaries? As the Atlantic Ocean floor gets weighed down around its margins by great thickness of continental sediments (i.e., geosynclines), it will be pushed farther and farther into the mantle, and eventually the oceanic lithosphere may break away from the continental lithosphere (Figure \(\PageIndex{12}\)). Mazama, erupted and collapsed 7,700 years ago, forming the large cavity (caldera) that now holds Crater Lake. Two parallel mountain ranges commonly develop above such a subduction zone a coastal range consisting of sedimentary strata and hard rock lifted out of the sea (accretionary wedge), and a volcanic range farther inland (volcanic arc). Roughly 3.2 million square kilometres (1.2 million square miles) in area, the Caribbean Plate borders the North American Plate, the South American Plate, the Nazca Plate and the Cocos Plate. Antarctic plate, Pacfic plate, Eurasia plate, India Plate, Africa plate. The west side of California is moving north, and the east side is moving south. The buoyancy of the mantle plume material creates a dome within the crust, causing it to fracture in a radial pattern, with three arms spaced at approximately 120 (Figure \(\PageIndex{5}\)). The east coast of North America is a passive margin and not a plate boundary. The Cocos plate is a geologically young oceanic tectonic plate.It is beneath the Pacific Ocean off the west coast of Central America. The park is right above the focus of the Great Alaska Earthquake of 1964, one of the two largest ever recorded (the other, in 1961, occurred along the subduction zone off western South America). Trees along the Washington coast were killed by salt-water invasion when the land suddenly dropped during the last great Cascadia Subduction Zone earthquake in the year 1700. Increased temperature and pressure at that depth cause the rocks to metamorphose and dehydrate (sweat). The Cocos plate is found on the west side of Mexico. The colliding continental material will not be subducted because it is too light (i.e., because it is composed largely of light continental rocks [SIAL]), but the root of the oceanic plate will eventually break off and sink into the mantle. Most of this water is present within the sheet silicate mineral serpentine which is derived from alteration of pyroxene and olivine near the spreading ridge shortly after the rocks formation. The inset shows these plates to be the Cocos plate and the North American plate. They are part of the volcanic arc that extends northeastward from the Aleutian Islands, across the Alaska Peninsula and Aniakchak National Monument, Katmai and Lake Clark national parks, and then bends eastward to Wrangell-St. Elias National Park. The series of hot spots that has been identified in the Atlantic Ocean may also have existed for several hundred million years, and thus may have contributed to rifting in roughly the same place on at least two separate occasions (Figure \(\PageIndex{13}\)). Plates move as rigid bodies, so it may seem surprising that the North American Plate can be moving at different rates in different places. The triangular zone of partial melting near the ridge crest is approximately 60 km thick and the proportion of magma is about 10% of the rock volume, thus producing crust that is about 6 km thick. Africa plate, Nazca plate, Scotia plate, Caribbean plate, Antarctic plate, North America plate. Photo courtesy of Robert J. Lillie. CC BY. Novarupta Lava Dome The eruption of Mt. There are also numerous small plates (e.g., Juan de Fuca, Cocos, Nazca, Scotia, Philippine, Caribbean), and many very small plates or sub-plates. Eurasia plate, Pacific plate, Africa plate, Caribbean plate, South America plate, Cocos plate, Juan de Fuca plate. Usually, one of the converging plates will move beneath the other, a process known as subduction. Listing total number of features into an ArcGIS Online feature pop-up, Convergent boundaries: where two plates are colliding. A visit to Olympic National Park is an opportunity to witness features of an accretionary wedge as they develop. The Caribbean Plate is a mostly oceanic tectonic plate underlying Central America and the Caribbean Sea off the north coast of South America. Lake Clark National Park and Preserve contains an active composite volcano with a profile and recent history reminiscent of Mt. Transform boundaries exist where one plate slides past another without production or destruction of crustal material. Transcribed image text: Question 1 (1 point) Saved Unclick all the other layers you've been using, and then click next to "plate boundary model" layer. The Cocos plate was created about 23 million years ago when a larger plate broke into two pieces. And at times, lower-silica components of their magma chambers erupt, producing basalt lava flows as well as cinders and volcanic bombs. The eastern boundary is a transform fault, the Panama Fracture Zone. Drum (right). The Cascades form above the line where the subducting plate extends to depths where it heats up, dehydrates and causes magma to form. Examples of continent-continent convergent boundaries are the collision of the India Plate with the Eurasian Plate, creating the Himalaya Mountains, and the collision of the African Plate with the Eurasian Plate, creating the series of ranges extending from the Alps in Europe to the Zagros Mountains in Iran. Yosemite Valley and Half Dome. Looking first at Washington, one sees Mt. If two tectonic plates collide, they form a convergent plate boundary. The Pacific Plate is the fastest, followed by the Australian and Nazca Plates. MORB Mid ocean ridge basalt subduction zones The southern boundary is a mid-oceanic ridge, the Galapagos Rise. Transcribed image text: Match each plate boundary with its appropriate type. The explanation is that plates move in a rotational manner. The line of active volcanoes, from Mt. Another divergent plate boundary is the East Pacific Rise, which separates the massive Pacific plate from the Nazca, Cocos, and North American plates. Later, most of the settlers coming on the Oregon Trail continued past central Oregon and Washington to the lush farmland of the Willamette Valley and Puget Sound, the low-lying region between the two rising mountain ranges. In 1966, Tuzo Wilson proposed that there has been a continuous series of cycles of continental rifting and collision; that is, break-up of supercontinents, drifting, collision, and formation of other supercontinents. Continental drift and sea-floor spreading became widely accepted around 1965 as more and more geologists started thinking in these terms. The water rises and melts rock in its path. This plate is small. It formed millions of years ago when the Farallon Plate split into the Cocos Plate and the Nazca Plate.. Beginning about 30 million years ago, so much of the Farallon Plate was consumed by subduction that the Pacific and North American plates were in contact, forming the San Andreas transform plate boundary in western California. This subduction-subduction-transform (SST) triple junction is referred to hereafter as the NACC triple junction. 20 Million Years Ago Basalt lava is thin and runny and will flow for miles and miles. Credit: Photo Courtesy of Robert J. Lillie. Photo courtesy of Robert J. Lillie. Mount Rainier is a 14,000 foot (4,300 meter) volcano in the Cascade Range developed above the place where the subducting Juan de Fuca Plate reaches sufficient depth to release hot fluids into the overriding North American Plate. The Cocos Plate is a tectonic plate beneath the Pacific Ocean off the west coast of Central America. Question: Tectonic Plates Use this map to answer the following questions. Along this fault, the Pacific plate is moving northwestward relative to the North American plate at an approximate rate of 16.4 feet per 100 years (5 cm/year). . Rainier in Mt. For example the Juan de Fuca Plate is actually three separate plates (Gorda, Juan de Fuca, and Explorer) that all move in the same general direction but at slightly different rates. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Solids and gases are also part of the mix. A transform plate boundary developed where the Pacific Plate was in contact with the North American Plate and the volcanism ceased in central California. An example is the San Andreas Fault, which extends from the southern end of the Juan de Fuca Ridge to the northern end of the East Pacific Rise (ridge) in the Gulf of California (Figures 10.28 and 10.29). The Philippine Sea Plate has an area of approximately 3400 square kilometers. When rifting of Pangea started at approximately 200 Ma, the fissuring was along a different line from the line of the earlier collision. This contortion attests to the great forces that squeezed and lifted the layers from the sea. NPS photo. The Sierra Nevada are a remnant of volcanoes that extended southward when the ancient Farallon Plate dove beneath the edge of North America. Credit: Photo Courtesy of Robert J. Lillie. USGS photo. The roots of ancient mountain belts, which are present along the eastern margin of North America, the western margin of Europe, and the northwestern margin of Africa, show that these land masses once collided with each other to form a mountain chain, possibly as big as the Himalayas. The San Andreas Fault and Queen Charlotte Fault are transform plate boundaries developing where the Pacific Plate moves northward past the North American Plate. Plate tectonics is the theory that the crust of the earth is broken up into giant slabs of rocks that sort of fit together like puzzle pieces. Rates of motions of the major plates range from less than 1 cm/y to over 10 cm/y. National Park Service sites in the Cascades reveal colorful landscapes that result from a varity of volcanic processes. These mega-earthquakes occur every 200 to 600 years or so, and the last one was in the year 1700. The Nazca plate is a large tectonic plate that underlies the Pacific Ocean near the western coast of South America. This plate moves north and slightly west towards the Caribbean plate and the North America plate. Detailed Description Map of the North American - Caribbean tectonic plate boundary. The subducted lithosphere descends into the hot mantle at a relatively shallow angle close to the subduction zone, but at steeper angles farther down (up to about 45). The subduction of the Nazca plate under southern Chile has a history of producing massive earthquakes, including the largest ever recorded on earth, the moment magnitude 9.5 1960 Valdivia earthquake. But thousands of eruptions over less than a million years have built Mount Rainier and other Cascade peaks to elevations of more than 10,000 feet (3,000 meters)! Along much of the boundary, the bulk of the motion occurs along the San Andreas Fault. Figures 10.4.2, 10.4.3, 10.4.5, 10.4.6, 10.4.7, 10.4.8, 10.4.9, 10.4.10, 10.4.11, 10.4.12, 10.4.13, 10.4.14: Steven Earle. Mazama that formed Crater Lake. A convergent plate boundary is a location where two tectonic plates are moving toward each other, often causing one plate to slide below the other (in a process known as subduction). Rainier were to suddenly and violently eruptso much that its magma chamber empties and the volcanic peak collapses in on itself. . Redwood National and State Parks, California Granite rocks found in national parks in the Sierra Nevada are the cooled and eroded remnants of magma chambers that fed ancient subduction zone volcanoes in California. The Pacific plate is subducting beneath the Philippine Sea plate to the east while the west/northwestern part of the Philippine Sea plate is subducting beneath the continental Eurasian plate. But parks in the Cascade Mountains within the same subduction zone are dramatically different. Regional tectonics of Central America are mainly controlled by the collision of the Cocos and the Caribbean plates. The Coast Range and Cascades are the two parallel mountain ranges that form the Cascadia Subduction Zone in the Pacific Northwest. Katmai volcano did collapse, but unlike Mt. Photo courtesy of Robert J. Lillie. The Caribbean plate is sandwiched between the North American and South American plates to the east and the Cocos, Nazca and North Andean plates to the west. Some of the processes taking place in this setting include: Spreading is hypothesized to start within a continental area with up-warping or doming related to an underlying mantle plume or series of mantle plumes. Right image National Park Service sites are shown in red. The Cocos Plate was created approximately 23 million years ago when the Farallon Plate broke into two pieces, which also created the Nazca Plate. This plate is rotating in a clockwise direction towards the Pacific plate. North America plate, Africa plate, Australia plate, Arabia plate, India plate, Filipino plate. The fact that the plates include both crustal material and lithospheric mantle material makes it possible for a single plate to be made up of both oceanic and continental crust.
Geneva Summer Concert Series,
Quicksand Deaths Video,
Recipes Using Contadina Sweet And Sour Sauce,
Harris Funeral Home Live Oak, Fl Obituaries,
Maine Masonic Scholarship,
Articles C