USGS photo. The southern boundary is a mid-oceanic ridge, the Galapagos Rise. Continental drift and sea-floor spreading became widely accepted around 1965 as more and more geologists started thinking in these terms. Stack the quarters with Washington on top, Oregon in the middle and California on the bottom. Subduction of the Farallon Plate beneath the entire West Coast created a line of volcanoes from Alaska to Central America. This plate is small. 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 subduction formed a line of volcanoes stretching all the way from Alaska to Central America. Layers of sandstone and shale deposited on the top of the Pacific Plate were later metamorphosed to quartzite and slate as the plate subducted beneath southern Alaska, and then shoved upward as part of the accretionary wedge. A sudden unlocking could produce an earthquake every bit as big as the one that occurred in Alaska in 1964, when a similar subduction zone boundary snap occurred. Is the Philippine plate convergent or divergent? The Nazca plate is a large tectonic plate that underlies the Pacific Ocean near the western coast of South America. This situation may not continue for too much longer, however. Solved Tectonic Plates Use this map to answer the following - Chegg The northern side is a divergent boundary with the Cocos Plate, the Galapagos Rise. Modified from "Beauty and the Beast: Plate Tectonics and the Landscapes of the Pacific Northwest", by Robert J. Lillie, Wells Creek Publishers, 92 pp., www.amazon.com/dp.1512211893. The western boundary is another mid-ocean ridge, the East Pacific Rise. The Cocos Plate is a tectonic plate beneath the Pacific Ocean off the west coast of Central America. Without warning the plane flew right through the eruption cloud at 25,000 feet (7,500 meters) altitude. The Cocos Plate Examine the interactive globe. But if the lava spills out from beneath the ocean, it encounters cold water and hardens quickly as a pile of pillows. New Guinea and the northern parts of New Zealand are part of the Australia plate. Over time, the San Andreas boundary has grown longer as the Farallon Plate split into two separate platesthe Juan de Fuca Plate on the north, and the Cocos Plate on the south. As they were caught in the vise between the converging Juan de Fuca and North American plates, some of the layers were so contorted that they are now in vertical orientations along the coast. Magmas high in silica are thick and pasty. Is the Cocos Plate convergent or divergent? 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. What type of plate boundary is the Cocos Plate? - Our Planet Today An accretionary wedge forms between the converging plates as material is scraped off the subducting plate. Along much of the boundary, the bulk of the motion occurs along the San Andreas Fault. 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. 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 \(\PageIndex{7}\)). 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. Not surprisingly, many of the engravings depict landscapes of national parks. Parks in the Cascadia Subduction Zone dramatically display the two distinct mountain ranges the Coast Range just above where the Juan de Fuca Plate begins to subduct, and the volcanic Cascade Range farther inland, where the top of the plate is deeper. A subduction zone will develop, and the oceanic plate will begin to descend under the continent. Produced under a Cooperative Agreement for earth science education between the National Park Service's Geologic Resources Division and the American Geosciences Institute. Copalis River, Washington We think that the Explorer Plate is also moving east, but we dont know the rate, and there is evidence that it is slower than the JDF Plate. Lassen Peak in Lassen Volcanic National Park is an amalgamation of rhyolite lava domes. 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. (Click on arrows and slide left and right to see labels.). 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. Finally, using a highlighter or colored pencil, label as many of the boundaries as you can as divergent, convergent, or transform. The west side of California is moving north, and the east side is moving south. Colors denote depth below sea level and elevation on land. Where are Puerto Rico and Hispaniola located on the plate? The water rises and melts rock in its path. This is what has happened in the Sierra Nevada of central and southern California, as represented by the granite-type rocks of Half Dome within Yosemite National Park shown on the California state quarter. Incipient rifting has begun along the Great Rift Valley of eastern Africa, extending from Ethiopia and Djibouti on the Gulf of Aden (Red Sea) all the way south to Malawi. What type of boundary is the Cocos Plate? The Sierra Nevada are a remnant of volcanoes that extended southward when the ancient Farallon Plate dove beneath the edge of North America. Observations. Once youve named most of the plates, draw arrows to show the general plate motions. Most of the igneous rocks were manufactured in the ocean and are basalt. Where is a divergent plate boundary located? 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). Caribbean Plate - Wikipedia 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. Regional tectonics of Central America are mainly controlled by the collision of the Cocos and the Caribbean plates. 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. And as time ticks on, the region awaits sudden release of energy locked between the converging plates as a devastating earthquake. Pangea, which existed from about 350 to 200 Ma, was not the first supercontinent. There is tremendous deformation of the pre-existing continental rocks, and creation of mountains from that rock, from any sediments that had accumulated along the shores (i.e., within geosynclines) of both continental masses, and commonly also from some ocean crust and upper mantle material. Caribbean Plate | Geology Page Which is true? These quarters featured iconic images that have special meaning to each state. This plate includes the islands that make up the Philipines and north to include parts of southern Japan. 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. The grinding action also produces devastating earthquakes, including some that result in giant tsunami waves. This plate is moving north east towards the Eurasia plate. Mt. 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). 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. Rocks in Yosemite, Kings Canyon, Sequoia, and Joshua Tree national parks contain exumed magma chamber rock that formed beneath the ancient volcanoes. In central and southern California the ancient volcanoes have largely eroded away. 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). The southerly side is a divergent boundary with the Antarctic Plate called the Southeast Indian Ridge (SEIR). Feature labels. Chapter 2 Flashcards | Quizlet And very large parks in the Southern Alaska Subduction Zone display magnificent mountains, rock layers and active volcanoes that tell the story ongoing plate convergence along the North Pacific Coast. The eruption of Mt. An ancient volcano, Mt. The Sierra Nevada are the eroded remnants of the volcanic arc developed when the Farallon Plate subducted beneath the continent. 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. Crater Lake partially fills the caldera of a volcano that erupted and collapsed in on Itself 7,700 years ago. 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. A variety of earthquakes shake the Pacific Northwest due to plate-tectonic activity. As originally described by Wegener in 1915, the present continents were once all part of a supercontinent, which he termed Pangea (meaning all land). The types are ocean-ocean, ocean-continent, and continent-continent. Most divergent boundaries are located at the oceanic ridges (although some are on land), and the crustal material created at a spreading boundary is always oceanic in character; in other words, it is mafic igneous rock (e.g., basalt or gabbro, rich in ferromagnesian minerals). Along these boundaries, earthquakes are common and magma (molten rock) rises from the Earths mantle to the surface, solidifying to create new oceanic crust. Now suppose the subduction processes that form the volcanoes were to stop, shutting off the magma supply that feeds the volcanoes. For example, the North American Plate includes most of North America, plus half of the northern Atlantic Ocean. Photo courtesy of Robert J. Lillie. What type of plate boundary is North American and Eurasian Plates? 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. Is the Nazca plate convergent or divergent? 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. Hydrothermal features on the flanks of Lassen Peak include numerous hot springs, mudpots and fumaroles that suggest there is still hot magma beneath the mountain. Are transform boundaries continental or oceanic? The boundary between the two plates is the Nootka Fault, which is the location of frequent small-to-medium earthquakes (roughly up to magnitude 5), as depicted by the red stars. What convergent boundary is formed between Caribbean plate and? - 2023 Pillow basalts attest to the oceanic origins of the rock layers, as they formed from lava flows that cooled on the ocean floor. Plate Tectonics and Volcanic Activity - National Geographic Society By 80 Ma, Africa had separated from South America, most of Europe had separated from North America, and India had separated from Antarctica. This plate is small. St. Helens in 1980. Examine the figure below. Some parks in the Sierra Nevada Mountains reveal igneous magma chamber rocks that represent the eroded remnants of an ancient subduction zone, when volcanoes similar to those found in the modern Cascade Mountains extended southward all the way through California. The lake partially fills a collapsed crater (caldera) that formed when a 12,000-foot (3,700-meter) composite volcano, Mt. Redoubt, an active volcano in Lake Clark National Park, illustrates how a volcano can pose an unexpected hazard in our modern age and why monitoring volcanic activity is so important (see photo below). That may not seem like much, but when tens of thousands of earthquakes occur over a few million years, coastal ranges form. At present, North and South America, Europe, and Africa are moving with their respective portions of the Atlantic Ocean. USGS photo. Shasta in California, and other Cascade Volcanoes. Forty million years ago, a large tectonic plate, known as the Farallon Plate, was between the Pacific and North American plates. and Alberta are also a result of continent-continent collisions. Magma from the mantle pushing up to fill the voids left by divergence of the two plates, Magma cooling more slowly in the lower part of the new crust and forming gabbro bodies, Figure \(\PageIndex{1}\): Plates tect2 en by the. Cocos Tectonic Plate | LAC Geo Feature labels. This subduction-subduction-transform (SST) triple junction is referred to hereafter as the NACC triple junction. North America plate, South America plate, Cocos plate. Mazama, violently erupted 7,700 years ago. It is likely that as many as 20 mantle plumes, many of which still exist, were responsible for the initiation of the rifting of Pangea along what is now the mid-Atlantic ridge (see Figure \(\PageIndex{10}\)). The Nazca plate is an oceanic tectonic plate in the southeastern Pacific Ocean that shares both convergent and divergent boundaries, corners multiple triple junctions, contains three seamount chains, overrides four hotspots, and is responsible for the creation of the Andean orogeny (Figure 1). Many National Park Service sites are found in active and ancient subduction zones. Volcanic and metamorphic rocks exposed in Kenai Fjords National Park reveal the incredible forces that occur at an ocean/continent subduction zone. Two arms of the triple junction can split to form an entire ocean. Mazama 7,700 years before, the material expelled from its magma chamber did not spew forth out of the top of the volcano.