cocos plate and north american plate boundary type
Yosemite National Park, California In the past, that was true. Modified from Parks and Plates: The Geology of our National Parks, Monuments and Seashores, by Robert J. Lillie, New York, W. W. Norton and Company, 298 pp., 2005, www.amazon.com/dp/0134905172. What type of plate boundary is Antarctic and Australian plate? That the Atlantic Ocean rift may have occurred in approximately the same place during two separate events several hundred million years apart is probably no coincidence. Transform faults do not just connect divergent boundaries. The line of active volcanoes, from Mt. This can be demonstrated by stacking the three quarters with California on the bottom, overlain by Oregon and then Washington. Without warning the plane flew right through the eruption cloud at 25,000 feet (7,500 meters) altitude. 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 \(\PageIndex{12}\)). Detailed Description Map of the North American - Caribbean tectonic plate boundary. As fluid basalt lava flows into the ocean it forms a pile of globular structures known as pillows. St. Helens, a lava dome later grew within the breached crater near the mountains summit. It is suggested that this type of valley eventually develops into a linear sea (such as the present-day Red Sea), and finally into an ocean (such as the Atlantic). . These mega-earthquakes occur every 200 to 600 years or so, and the last one was in the year 1700. This is the zone where the two plates have been locked together since the last great earthquake occurred in the year 1700. Legal. Where tectonic plates converge, the one with dense, thin oceanic crust subducts beneath the one with thick, more buoyant continental crust. 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 \(\PageIndex{13}\)). Another, Wrangell-St. Elias National Park, is a vast region that extends across the accretionary wedge and volcanic arc, and is built of accreted terranes. 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. But unlike Mt. Sea lions resting on layers of pillow basalt that formed beneath the ocean and were uplifted as part of the accretionary wedge. What caused the Chile earthquake of 1960? Are transform boundaries continental or oceanic? Lake Clark National Park That may not seem like much, but when tens of thousands of earthquakes occur over a few million years, coastal ranges form. 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). As a result of this collision, the oceanic Cocos plate is subducted below the Caribbean along the Mesoamerican trench plate at speeds ranging from 2 in. Rather, it flowed underground to a vent 6 miles (10 kilometers) away! Half Dome in Yosemite National Park is made of granite that solidified from magma tens of millions of years ago, when a subduction zone extended along the entire west coast. It runs along the west coast of Mexico and western Caribbean countries. Silica-rich ash melted and coated the hot engine turbines with glass, causing all four of them to shut down. 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. 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]. Like Mt. Novarupta Lava Dome Expert Answer. This map shows the boundaries between the major plates. It is assumed that the relative lack of strength of the partial melting zone facilitates the sliding of the lithospheric plates. It runs from the tip of South America eastwards to form a barrier between the Antarctic plate and the South America plate. This subduction-subduction-transform (SST) triple junction is referred to hereafter as the NACC triple junction. Examples of ocean-continent convergent boundaries are subduction of the Nazca Plate under South America (which has created the Andes Range) and subduction of the Juan de Fuca Plate under North America (creating the mountains Garibaldi, Baker, St. Along these boundaries, earthquakes are common and magma (molten rock) rises from the Earths mantle to the surface, solidifying to create new oceanic crust. The San Andreas Fault and Queen Charlotte Fault are transform plate boundaries developing where the Pacific Plate moves northward past the North American Plate. An accretionary wedge forms between the converging plates as material is scraped off the subducting plate. The Philippine Sea Plate has an area of approximately 3400 square kilometers. This plate is moving north east towards the Caribbean and North America plates. rare Examine the interactive globe. By 80 Ma, Africa had separated from South America, most of Europe had separated from North America, and India had separated from Antarctica. The rising hot water causes overlying rock to melt, generating magma that at times erupts out on the surface as lava flows and other materials forming Mt. Regional tectonics of Central America are mainly controlled by the collision of the Cocos and the Caribbean plates. 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. Along much of the boundary, the bulk of the motion occurs along the San Andreas Fault. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. The west side of California is moving north, and the east side is moving south. The Cascadia Subduction Zone has two parallel mountain ranges separated by a low region near sea level. 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. WrangellSt. Usually, one of the converging plates will move beneath the other, a process known as subduction. Sediment that has accumulated on the continental slope is thrust up into an accretionary wedge, and compression leads to thrusting within the continental plate (Figure \(\PageIndex{7}\)). Introduction The Cocos Plate is a relatively small sized, triangular-shaped oceanic plate located just west of Mexico and the Caribbean. A mature island arc develops into a chain of relatively large islands (such as Japan or Indonesia) as more and more volcanic material is extruded and sedimentary rocks accumulate around the islands. About 200 million years ago a large tectonic plate (called the Farallon Plate) started to subduct beneath the western edge of North America. It is released when the oceanic crust is heats and then rises and mixes with the overlying mantle. 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 \(\PageIndex{5}\)). Jennifer Natoli was a seasonal ranger at Redwood National and State Parks in California. Plate Tectonics and Our National ParksSite Index, Plate TectonicsThe Unifying Theory of Geology, Tectonic Settings of NPS SitesMaster List, ORCAOregon Caves National Monument, Oregon [, SEKIKings Canyon National Park, California[, YOSEYosemite National Park, California[. Examples of ocean-ocean convergent zones are subduction of the Pacific Plate beneath the North America Plate south of Alaska (Aleutian Islands) and beneath the Philippine Plate west of the Philippines, subduction of the India Plate beneath the Eurasian Plate south of Indonesia, and subduction of the Atlantic Plate beneath the Caribbean Plate (see Figure \(\PageIndex{1}\)). Mazama that formed Crater Lake. If spreading along the mid-Atlantic ridge continues to be slower than spreading within the Pacific Ocean, the Atlantic Ocean will start to close up, and eventually (in a 100 million years or more) North and South America will collide with Europe and Africa. The eastern margins of North and South America and the western margins of Europe and Africa are called passive margins because there is no subduction taking place along them. 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. National Park Service sites in the Cascades reveal colorful landscapes that result from a varity of volcanic processes. They contain explosive volcanoes formed as fluids rise from the top of the subducting plate and generate magma as they melt their way to the surface. Layers of sand and mud, deposited on the ocean floor and later turned into the sedimentary rocks sandstone and shale, are seen above the pillows. Effects of the 1964 earthquake are quite spectacular in the park; the coastline dropped so much that in places it lies submerged beneath about 8 feet (2.5meters) of water. The Coast Range (accretionary wedge), Great Valley (forearc basin), and Sierra Nevada (volcanic arc) still reflect the subduction zone topography. Rainier National Park is an active composite volcano rising more than 14,000 feet above sea level. This plate is rotating counter clockwise in towards the Pacific plate. The types are ocean-ocean, ocean-continent, and continent-continent. To see the timing of these processes for yourself, go to time lapse of Continental Movements. Colors denote depth below sea level and elevation on land. This plate is small. Cocos Plate; Type: Minor: Approximate area: 2,900,000 km 2: Movement 1: north-east: Speed 1: 67 mm/year: . 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. Shasta in California, and other Cascade Volcanoes. Step 2/2. 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, The largest earthquakes occur near the surface where the subducting plate is still cold and strong. The rocks on top of the plate are metamorphosed due to the great temperatures and pressures at those depths. The apparent line of collision runs between Norway and Sweden, between Scotland and England, through Ireland, through Newfoundland, and the Maritimes, through the northeastern and eastern states, and across the northern end of Florida. 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. Modified from Earth: Portrait of a Planet", by S. Marshak, 2001, W. W. Norton & Comp., New York. North America plate, Australia plate, Antarctic plate, Nazca plate, Filipino plate, Cocos plate, Juan de Fuca plate. Pangea, which existed from about 350 to 200 Ma, was not the first supercontinent. What plate boundary shows the collision of two plates? Unclick all the other layers you've been using, and then click next to . The water rises and melts rock in its path. Australia plate, Eurasia plate, Africa plate, Arabia plate. A subduction zone will develop, and the oceanic plate will begin to descend under the continent. Ancient magma chamber rocks can be exposed if subduction stops and the volcanoes erode away. Pillow basalts attest to the oceanic origins of the rock layers, as they formed from lava flows that cooled on the ocean floor. The explanation is that plates move in a rotational manner. Two arms of the triple junction can split to form an entire ocean. Kenai Fjords National Park lies within a coastal mountain range (accretionary wedge) formed as the Pacific Plate subducts beneath southern Alaska. Katmai National Park Divergent boundaries are spreading boundaries, where new oceanic crust is created from magma derived from partial melting of the mantle caused by decompression as hot mantle rock from depth is moved toward the surface (Figure \(\PageIndex{3}\)). The Philippine Sea Plate. The western boundary is another mid-ocean ridge, the East Pacific Rise. Once youve named most of the plates, draw arrows to show the general plate motions. The other piece became the Nazca plate.The Cocos plate also broke into two pieces, creating the small Rivera plate. 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. The spectacular pillow lavas seen on the road up Hurricane Ridge indicate that lava formed on the sea floor and was later uplifted. 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. This subduction forms the volcanoes of Guatemala, El Salvador, Nicaragua, and Costa Rica, also known as the Central America Volcanic Arc. Volcanic and metamorphic rocks exposed in Kenai Fjords National Park reveal the incredible forces that occur at an ocean/continent subduction zone. The part of California west of the San Andreas Fault and all of Baja California are on the Pacific Plate. At present, North and South America, Europe, and Africa are moving with their respective portions of the Atlantic Ocean. When the plates suddenly let go, a massive earthquake will shake the entire Pacific Northwest, a series of tsunami waves will pound the Coast, and landslides will make it difficult to reach some of those in need. And as time ticks on, the region awaits sudden release of energy locked between the converging plates as a devastating earthquake. Note that the dark blue line does not run further up the coast. Examples of ocean-continent convergent boundaries are subduction of the Nazca Plate under South America (which has created the Andes Range) and subduction of the Juan de Fuca Plate under North America (creating the mountains Garibaldi, Baker, St. Helens, Rainier, Hood, and Shasta, collectively known as the Cascade Range). As the Juan de Fuca Plate (lower cookie) subducts beneath the North American Plate (upper cookie), the layers are scraped off the ocean floor and pile up as the Coast Range. This plate includes India and the surrounding India Ocean. Is the Philippine plate convergent or divergent? Garibaldi to Lassen Peak, coincides with the north-to-south extent of the subducting plate boundary. What type of boundary is the San Andreas Fault? Accessibility StatementFor more information contact us atinfo@libretexts.org. By the end of 1967 the Earths surface had been mapped into a series of plates (Figure \(\PageIndex{1}\)). The boundary between the Pacific and North American plates in California is a transform plate boundary marked by the San Andreas strike-slip fault. On Dec. 15, 1989 a jet with 244 passengers and crew was en route from Amsterdam to Anchorage. Cocos Tectonic 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. This plate includes all of North America, Greenland, the eastern most part of Russia, northern Japan, and the northwestern part of the Atlantic ocean. For example, the North American Plate includes most of North America, plus half of the northern Atlantic Ocean. During the same period, the Atlantic Ocean began to open up between northern Africa and North America, and India broke away from Antarctica. 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. In this region, the Cocos Plate is subducting beneath the North America and Caribbean Plates (ocean-continent convergence), and the South and North America Plates are subducting beneath the Caribbean Plate (ocean-ocean convergence). The Philippine Plate, also known as the Philippine Sea Plate, is a small tectonic plate between the Eurasian Plate and the Pacific Plate. The volcano is still active, having erupted in 1931. 40 Million Years Ago Once this happens, the continents will no longer continue to move apart because the spreading at the mid-Atlantic ridge will be taken up by subduction. Photo courtesy of Robert J. Lillie. Before we talk about processes at plate boundaries, its important to point out that there are never gaps between plates. Photo courtesy of Robert J. Lillie. When caught between the converging Juan de Fuca and North American plates, the pillows and other ocean layers can be lifted upward to more than a mile above sea level. Modified from Beauty from the Beast: Plate Tectonics and the Landscapes of the Pacific Northwest, by Robert J. Lillie, Wells Creek Publishers, 92 pp., 2015, www.amazon.com/dp/1512211893. The Cocos Plate was created approximately 23 million years ago when the Farallon Plate broke into two pieces, which also created the Nazca Plate. The magma, which is lighter than the surrounding mantle material, rises through the mantle and the overlying oceanic crust to the ocean floor where it creates a chain of volcanic islands known as an island arc. Plate Tectonics and Our National Parks (2020), Text and Illustrations by Robert J. Lillie, Emeritus Professor of Geosciences, Oregon State University [E-mail]. Visitors can witness mountains as they are forming, and sometimes experience the accompanying earthquake and volcanic activity. The Cocos Plate is a young oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America, named for Cocos Island, which rides upon it. The devastating 1985 Mexico City earthquake and the 2017 Chiapas earthquake were results of the subduction of the Cocos Plate beneath the North American Plate. Three others, Aniakchak National Monument, Katmai National Park, and Lake Clark National Park, are farther inland, along the active volcanic arc. Images above modified from Oregon's Island in the Sky: Geology Road Guide to Marys Peak, by Robert J. Lillie, Wells Creek Publishers, 75 pp., 2017, www.amazon.com/dp/1540611965. Is the Cocos Plate convergent or divergent? Many rift valleys are part of " triple junctions," a type of divergent boundary where three tectonic plates meet at about 120 angles. A forearc basin develops in the low area between the two mountain ranges. South America plate, Antarctic plate, Eurasia plate, North America plate, Arabia plate, India plate, Australia plate. In doing so the magma is enriched in silica, because high-silica minerals commonly are the first ones to melt. Examine the figure below. The Pacific Plate is almost entirely oceanic, but it does include the part of California west of the San Andreas Fault. Wrangell, a 14,163 foot (4,317 meter) volcano that last erupted during the early part of the 20th Century. Likewise, individual volcanic eruptions may add only a thin layer to the surface. The Cascades form above the line where the subducting plate extends to depths where it heats up, dehydrates and causes magma to form. The southerly side is a divergent boundary with the Antarctic Plate called the Southeast Indian Ridge (SEIR). Vents and fractures (also called fissures ) in these mid-ocean ridges allow magma and gases to escape into the ocean. In central and southern California the ancient volcanoes have largely eroded away. Forty million years ago, a large tectonic plate, known as the Farallon Plate, was between the Pacific and North American plates. This contortion attests to the great forces that squeezed and lifted the layers from the sea. If this continues without changing for another couple hundred million years, we will be back to where we started, with one supercontinent. Gases may be trapped in them under high pressure. CC BY. Remove the Oregon quarter to reveal cooled magma chamber rocks below. Left image This map shows the Juan de Fuca (JDF) and Explorer Plates off the coast of Vancouver Island. This plate is rotating in a clockwise direction towards the Pacific plate. The resulting magmas can therefore have a variety of compositions, ranging from the original (low-silica) basalt, to (intermediate-silica) andesite, all the way up to (high-silica) rhyolite. Kenai Fjords National Park Similarly the South American Plate extends across the western part of the southern Atlantic Ocean, while the European and African plates each include part of the eastern Atlantic Ocean. If two tectonic plates collide, they form a convergent plate boundary. The plates are made up of crust and the lithospheric part of the mantle (Figure \(\PageIndex{2}\)), and even though they are moving all the time, and in different directions, there is never a significant amount of space between them. National Park Service sites are shown in red. Today Listing total number of features into an ArcGIS Online feature pop-up, Convergent boundaries: where two plates are colliding. Plates move as rigid bodies, so it may seem surprising that the North American Plate can be moving at different rates in different places. Hood in Oregon, Mt. Modified from The Geology of our National Parks, Monuments and Seashores, by Robert J. Lillie, New York, W. W. Norton and Company, 298 pp., 2005, www.amazon.com/dp/0134905172. o The boundary is found far from the North American Plate in the Pacific Ocean The boundary appears to be situated on a mid-ocean ridge ( ) The boundary is found close to the North American Plate.