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29-660: The CAVA is formed by the subduction of the Cocos and Nazca Plates underneath the North American, Caribbean and Panama plates. Its structure is heterogeneous, by a combination of oceanic and continental crust fragments. Gazel et al. (2021) define four domains of the CAVA: North American plate slivers (continental crust), the Guatemala Suture Zone (GSZ) (continental crust), continental blocks of

58-544: A Cretaceous- Eocene ancient arc (∼130-50 Ma), an Oligocene - Miocene arc (∼30-5 Ma) and the Recent volcanic front. The ancient arc has a more acidic calc-alkaline composition, wheres the Oligocene-Miocene arc is transitional towards basaltic tholeiiic composition, and the volcanic front is mostly basaltic tholeiitic in composition. The causes of these change are not well understood, but one explanation could be that

87-855: A paper published in August 2017. The Coiba Transform Fault (CTF) separates the Coiba plate from the Malpelo plate. The slab tear between the microplates could have happened during the fragmentation of the Farallon plate , in the Oligocene , around 30 to 25 Ma. The Coiba Ridge, a submerged part of the plate probably formed at the Galápagos hotspot , in contrast with the Malpelo Ridge , a product of volcanic activity. The researchers led by Gordon used

116-453: Is a 1,350-kilometre-long (840 mi) and up to 300-kilometre-wide (190 mi) feature on the ocean floor of the northern Nazca plate that includes the Galápagos archipelago at its western end. It is being subducted under South America with the rest of the Nazca plate. The absolute motion of the Nazca plate has been calibrated at 3.7 cm/year (1.5 in/year) east motion (88°), one of

145-406: Is part of a magmatic arc , while the northern one is associated with several active margins . Different types of faults also exist within each regime and further serve to differentiate the northern and southern regions' geologic and tectonic histories from one another. The magmatic record of Central America begins with Permian- Triassic (∼283-215) granites and gneisses of arc affinity, formed in

174-582: The East Pacific Rise and the Chile Rise , respectively. The movement of the Nazca plate over several hotspots has created some volcanic islands as well as east–west running seamount chains that subduct under South America . Nazca is a relatively young plate in terms of the age of its rocks and its existence as an independent plate, having been formed from the breakup of the Farallon plate about 23 million years ago. The oldest rocks of

203-728: The Middle America Trench . An interesting case of volcanic activiy evolution is recorded in Nicaragua, which started ∼130 Ma. Nicaragua nowadays has continental crust in its northern part (the Patuca Block), that transitions into oceanic crust (Mesquito Composite Oceanic Terrane, MCOT) up to northwestern Costa Rica (Santa Elena Block, Nicoya Block). Older volcanic rocks crop out in the Patuca Block, dating Middle Jurassic (∼170 Ma). The ancient Nicaraguan arc comprises

232-750: The Nazca region of southern Peru , is an oceanic tectonic plate in the eastern Pacific Ocean basin off the west coast of South America . The ongoing subduction , along the Peru–Chile Trench , of the Nazca plate under the South American plate is largely responsible for the Andean orogeny . The Nazca plate is bounded on the west by the Pacific plate and to the south by the Antarctic plate through

261-472: The Serranía de Baudó , an isolated mountain chain in northwestern Chocó , Colombia. The Coiba plate was identified as early as 1981 by Pennington, and later in 1988 by Adamek et al. It is named after Coiba , to the south of mainland Panama, bordering the plate. It was presented together with the newly defined Malpelo plate by Tuo Zhang and lead-researcher Richard G. Gordon et al. of Rice University in

290-577: The Caribbean plate, and Pacific-affinity accreted complexes (oceanic crust). The Cocos tectonic plate is located along the western edge of Central America . The latter is along the western edge of the Caribbean tectonic plate and can be split into two distinct regimes. These regimes are demarcated roughly by the Costa Rican - Nicaraguan border and can be differentiated by the different tectonic histories of each respective area. The southern portion

319-700: The Central American Volcanic Arc; while the subduction of the Cocos Ridge is a continual event that has influenced volcanism in Central America, the subduction of the Coiba Ridge—a microplate in the region—is thought to be the triggering event that instigated changes in volcanic activity in the geologic past. In short, the interaction of numerous tectonic plates—namely the Cocos, Caribbean, North American, and Coiba plates—over

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348-486: The Costa Rican Miravalles , Irazú , and Poás volcanoes. Many remain sporadically active to this day, and likely will continue to be active into the future, as geologic and tectonic processes continue to shape the region. 10°26′31″N 84°41′17″W  /  10.44194°N 84.68806°W  / 10.44194; -84.68806 Nazca plate The Nazca plate or Nasca plate , named after

377-401: 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 . A second triple junction occurs at the northwest corner of the plate where the Nazca, Cocos, and Pacific plates all join off the coast of Colombia . Yet another triple junction occurs at the southwest corner at

406-643: The Nazca plate, Juan de Fuca plate , and the Cocos plate was the Farallon plate , which split in the late Oligocene , about 22.8 Mya , a date arrived at by interpreting magnetic anomalies . Subduction under the South American continent began about 140 Mya, although the formation of the high parts of the Central Andes and the Bolivian orocline did not occur until 45 Mya. It has been suggested that

435-496: The Nazca plate; this had a magnitude of 8.2 M w {\displaystyle M_{w}} , which at that time was the strongest instrumentally recorded earthquake occurring deeper than 300 km (190 mi). Aside from the Juan Fernández Islands , this area has very few other islands that are affected by the earthquakes resulting from complicated movements at these junctions. The precursor of

464-616: The South American plate and the Andes Mountains , forming the Peru–Chile Trench . The southern side is a divergent boundary with the Antarctic plate, the Chile Rise , where seafloor spreading permits magma to rise. The western side is a divergent boundary with the Pacific plate , forming the East Pacific Rise . The northern side is a divergent boundary with the Cocos plate , the Galapagos Rise . The subduction of

493-400: The area has been geologically active since at least 12 Ma, as evidenced by plate and plate boundary movements, as well as scarp subduction in the area. A gap in volcanism in Central America between 12 Ma and 5 Ma is understood to have occurred as well. Furthermore, the subduction of the Cocos tectonic plate itself is not thought to be what caused some of the changes in volcanism associated with

522-562: The earlier eruption having higher levels of carbon dioxide and water vapor , and the later eruption degassing many of its volatiles—markedly different styles of eruption occurred, with the 1992 eruption of Cerro Negro much more explosive than its 1995 counterpart. Other volcanos in Central America include the Salvadorian Santa Ana , Izalco , and San Salvador volcanoes, the Nicaraguan Masaya volcano, and

551-488: The fastest absolute motions of any tectonic plate. The subducting Nazca plate, which exhibits unusual flat slab subduction , is tearing as well as deforming as it is subducted (Barzangi and Isacks). The subduction has formed and continues to form the volcanic Andes Mountain Range. Deformation of the Nazca plate even affects the geography of Bolivia , far to the east (Tinker et al.). The 1994 Bolivia earthquake occurred on

580-651: The intersection of the Nazca, Pacific, and Antarctic plates off the coast of southern Chile . At each of these triple junctions an anomalous microplate exists, the Galapagos microplate at the northern junction and the Juan Fernandez microplate at the southern junction. The Easter Island microplate is a third microplate that is located just north of the Juan Fernandez Microplate and lies just west of Easter Island . The Carnegie Ridge

609-446: The mountains were forced up by the subduction of the older and heavier parts of the plate, which sank more quickly into the mantle . 15°S 85°W  /  15°S 85°W  / -15; -85 Coiba plate The Coiba plate is a small tectonic plate (microplate) located off the coasts south of Panama and northwestern Colombia . It is named after Coiba , the largest island of Central America, just north of

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638-447: The past several million years has helped facilitate the continual existence of the Central American Volcanic Arc, influencing the tectonic and broad geologic history of the area. The Central American Volcanic Arc consists of hundreds of volcanic formations, including stratovolcanoes , composite volcanos , calderas , and lava domes . From a depositional standpoint, ash falls , ash flows, and deposits of tephra are prevalent throughout

667-535: The plate are about 50 million years old. A triple junction , the Chile Triple Junction , occurs on the seafloor of the Pacific Ocean off Taitao and Tres Montes Peninsula at the southern coast of Chile . Here, three tectonic plates meet: the Nazca plate, the South American plate , and the Antarctic plate . The eastern margin is a convergent boundary subduction zone under

696-687: The plate offshore southern Panama. It is bounded on the west by the Cocos plate , on the south by the Malpelo plate , on the east by the North Andes plate , and on the north by the Panama plate . This microplate was previously assumed to be part of the Nazca Plate, forming the northeastern tongue of the Nazca plate together with the Malpelo plate. Bordering the Coiba plate on the east are the north–south striking Bahía Solano Fault and east of that,

725-735: The region. Carbon and argon isotope dating has been used to date these deposits to the Quaternary , and it is suspected that several of these volcanos have been sporadically active for much of the past 200,000 years. Some volcanos in the area have even produced large explosive eruptions in the recent past, including the October 25 , 1902 , eruption of the Santa Maria volcano in Guatemala . This Plinian eruption spewed upwards of twenty cubic kilometers of ash almost thirty kilometers into

754-683: The second and third episodes, there are Jurassic- Cretacous island arc volcanic rocks of paleo-Pacific origin that got accreted into the GSZ and the MCOT. A fourth pulse is only located in the Talamanca Unit of the Panama plate, of age Maastrichtian-Bartonian (∼71-39 Ma), of mainly tholeiitic composition. The fifth and sixth magmaic pulses (Oligocene-Pliocene and Quaternary) define the CAVA, both parallel to

783-408: The sky. Much of this ash was fine-grained, averaging less than 2 millimeters in size. Similarly, Cerro Negro , a 250-meter-tall volcano in northwest Nicaragua , erupted in 1971, 1992, and 1995. The two latter eruptions, occurring in the 1990s, had similar magmatic compositions to one another, both broadly basaltic. However, as the water and carbon dioxide contents of each eruption were different—with

812-539: The slab was richer in volatiles during the ancient arc, or the melts could maintain their volatile composition. This Caribbean-Cocos tectonic plate interaction can further explain the volcanism and geologic history of the region since the Miocene. While previous literature has shown a wide range of ages for the subduction of the Cocos plate, it is now believed that this subduction began between two million years ago and three million years ago (between 2 Ma and 3 Ma), though

841-528: The western margin of Pangea . A second episode comprises a Jurassic -Berriasian of continental rift vulcanism, associated with the opening of the proto-Caribbean and the Gulf of Mexico. The third pulse includes calc-alkaline vulcanism and intrusive rocks ranging from Aptian-Ypresian (∼124-50 Ma) present in the continental slivers of the Caribbean plate, the MCOT and the Santa Elena and Nicoya units. Between

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