Flat slab subduction

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A diagram representing flat slab subduction Flat slab subduction.png
A diagram representing flat slab subduction

Flat slab subduction is characterized by a low subduction angle (<30 degrees to horizontal) beyond the seismogenic layer and a resumption of normal subduction far from the trench. [1] A slab refers to the subducting lower plate. A broader definition of flat slab subduction includes any shallowly dipping lower plate, as in western Mexico. Flat slab subduction is associated with the pinching out of the asthenosphere, an inland migration of arc magmatism (magmatic sweep), and an eventual cessation of arc magmatism. [2] The coupling of the flat slab to the upper plate is thought to change the style of deformation occurring on the upper plate's surface and form basement-cored uplifts like the Rocky Mountains. [2] [3] The flat slab also may hydrate the lower continental lithosphere [2] and be involved in the formation of economically important ore deposits. [4] During the subduction, a flat slab itself may deform or buckle, causing sedimentary hiatus in marine sediments on the slab. [5] The failure of a flat slab is associated with ignimbritic volcanism and the reverse migration of arc volcanism. [2] Multiple working hypotheses about the cause of flat slabs are subduction of thick, buoyant oceanic crust (15–20 km) [6] and trench rollback accompanying a rapidly overriding upper plate and enhanced trench suction. [7] The west coast of South America has two of the largest flat slab subduction zones. [2] Flat slab subduction is occurring at 10% of subduction zones. [3]

Contents

History of idea

The idea has its beginnings in the late 1970s. [8] Seismic studies of the Andean margin seemed to show a zone of subhorizontal lower plate at a depth of 100 km. The Cornell-Carnegie debate between Cornell University geophysicists and workers at the Carnegie Institute of Washington centered on whether local deployments of seismometers would yield better results than looking at global (teleseismic) data. The Carnegie Institution seemed to have won the day with the local deployment imaging the flat slab where teleseismic data argued for a shallowing dipping slab with no near horizontal zone. [9] The idea was taken up to explain the Laramide orogeny, as the flat slab subduction zones on the Andean margin are associated with more inboard surface deformation and magmatic gaps. [2] Flat slab subduction is an active area of research; the causal mechanisms for its occurrence have not been sorted out.

Causal mechanisms and consequences of flat slab subduction

Causal mechanisms

There are several working hypotheses for the initiation of flat slab subduction. The buoyant ridge hypothesis seems to be favored at the moment. [3]

Subduction of buoyant oceanic crust

The subduction of bathymetric highs such as aseismic ridges, oceanic plateaus, and seamounts has been posited as the primary driver of flat slab subduction. [3] The Andean flat slab subduction zones, the Peruvian slab and the Pampean (Chilean) flat slab, are spatially correlated with the subduction of bathymetric highs, the Nazca Ridge and the Juan Fernandéz Ridge, respectively. The thick, buoyant oceanic crust lowers the density of the slab, and the slab fails to sink into the mantle after coming to a shallow depth (~100 km) due to the lessened density contrast. [6] This is supported by the fact that all slabs are under ~50 Ma. [10] However, there are cases where aseismic ridges on the same scale as the Nazca Ridge are subducting normally, and cases where flat slabs are not associated with bathymetric highs. [11] There are few flat slabs in the Western Pacific in areas associated with the subduction of bathymetric highs. [12] Geodynamic modeling has called into question whether buoyant oceanic crust alone can generate flat slab subduction. [10]

Trenchward motion of overriding plate with cratonic keel

Another explanation for slab flattening is the lateral movement of the overriding plate in a direction opposite to that of the downgoing slab. The overriding plate is often equipped with a cratonic keel of thick continental lithosphere which, if close enough to the trench, can impinge upon the flow in the mantle wedge. [7] Trench suction is included in this causal mechanism. Trench suction is induced by the flow of the asthenosphere in the mantle wedge area; trench suction increases with subduction velocity, a decrease of the mantle wedge thickness, or an increase in the mantle wedge viscosity. [13] Trench retreat is motion of the trench in a direction opposite to that of plate convergence thought to be related to the position of the trench along the larger subduction zone with retreat occurring near the edges of subduction zones. [14] Modeling experiments have shown that if the cratonic lithosphere is thick and the trench retreats, the shutdown of the mantle wedge increases trench suction to an extent that the slab flattens. [7]

Consequences

Delay in the eclogitization

Eclogite is a dense (3.5 g/cu. cm), garnet-bearing rock that is formed as the oceanic crust subducts to zones of high pressure and temperature. The reaction that forms eclogite dehydrates the slab and hydrates the mantle wedge above. The now denser slab more effectively sinks. [15] A delay in eclogitization could arise through the subduction of zone thicker oceanic lithosphere without deeply penetrating faults. Oceanic crust is normally faulted at the trench rise by the bending of the plate as it subducts. This may be an effect or a cause of flat slab subduction, but it seems as though it is more likely an effect. A resumption of normally dipping subduction beyond the flat slab portion is associated with the eclogite reaction, and the amount of time needed to accumulate enough eclogite for the slab to start sinking may be what limits temporal scale of flat slab subduction. [6]

Magmatic gaps and adakitic volcanism

As the subducting plate flattens there is an inboard migration in the magmatic arc that can be tracked. In the Chilean flat slab region (~31–32 degrees S), around 7–5 Ma there was an eastward migration, broadening and gradual shutdown down of the volcanic arc associated with slab flattening. [16] This occurs as the previous magmatic arc position on the upper plate (100–150 km above subducting plate) is no longer aligned with the zone of partial melting above the flattening slab. [17] The magmatic arc migrates to a new location that coincides with the zone of partial melting above the flattening slab. Magmatism before the Laramide orogeny migrated all the way to western South Dakota. [2] Eventually, the magmatic activity above the flat slab may completely cease as the subducting plate and upper plate pinch out the mantle wedge. [2] Upon the failure of the flat slab, the mantle wedge can again start circulating hot asthenosphere (1300 degrees C) in an area that has been heavily hydrated, but that had not produced any melt; this leads to widespread ignimbritic volcanism, which is seen in both the Andean flat slab effected regions and the western United States. [18]

Adakites are dacitic and andesitic magmas that are highly depleted in heavy rare-earth elements and high strontium/yttrium ratios and may be derived of melting of the oceanic crust. [17] Adakites are thought to erupt or be emplaced during the transition from normally dipping subduction to flat subduction as the magmatic arc widens and migrates more inland. [17] Adakitic rocks can be seen in modern Ecuador, [19] a possible incipient flat slab zone, and in central Chile there are 10-5 Ma adakitic rocks. [20] Thus, adakitic rocks could be used as marker of past episodes of flat slab subduction.

Surface deformation

Flat slabs are thought to result in zones of broad, diffuse deformation in the upper plate located far landward from the trench. [3] Flat slab subduction is associated with basement-cored uplifts also known as "thick-skinned" deformation of the overriding plate like the Sierra Pampeanas in South America possibly associated with the subduction of the Juan Fernandéz Ridge. [21] These areas of basement-cored uplifts are visually correlated with flat slab subduction zones. [16] In contrast, "thin-skinned" deformation is the normal mode of upper plate deformation, and does not involve basement rock. Crustal shortening is observed to extend farther inland than in normally dipping subduction zones; the Sierra Pampeanas are over 650 km east of the trench axis. [21] Flat slabs have been used as an explanation for the Laramide Orogeny [18] and the central Altiplano-Puna region. [22] Another interesting feature that may be associated with the flat slab subduction of the Nazca Ridge is the Fitzcarrald arch located in the Amazonian Basin. The Fitzcarrald arch is a long-wavelength, linear topographic feature extending from eastern Peru to western Brazil beyond the Subandean thrust front into an undeformed area and rising ~600 masl. [23] The Fitzcarrald arch has the effect of splitting the Amazonian Basin into three subbasins: northern Amazonian foreland basin, southern Amazonian foreland basin, and the eastern Amazonian foreland basin. [24] [25]

Seismicity

The shape of the flat slab is constrained through earthquakes within the subducting slab and the interface between the upper plate and the subducting slab. [16] Flat slab zones along the Andean margin release 3–5 times more energy through upper plate earthquakes than adjacent, more steeply dipping subduction zones. [3] Upper plate earthquake focal mechanisms indicate that stress is aligned parallel with motion of the plate, and that stress is transmitted high into the upper plate from the lower. [26] The reason for this enhanced seismicity is more effective coupling of the upper and lower plates. In normal subduction zones the coupling interface, the area in which the two plates are in close proximity, between the two plates is ~100–200 km long, but in flat slab subduction zones the coupling interface is much longer, 400–500 km. [26] Although the lower lithosphere of the upper deforms plastically, numerical modeling has shown stress can be transmitted to crustal regions which behave in a brittle fashion. [27] Along the subducting plate seismicity is more variable, especially intermediate-depth earthquakes. The variability may be controlled by the thickness of the crust and how efficiently it can release water. Thick crust that is not as deeply fractured by trench rise normal faulting may not dehydrate rapidly enough to induce intermediate-depth earthquakes. [1] The Peruvian flat slab lacks significant intermediate-depth earthquakes and is associated with the subduction of the ~17 km thick Nazca Ridge. [1]

Andean flat slabs

In the late 1970s early research recognized the unique nature of the two large flat slab subduction zones along the Andean margin of South America. [28] [29] Two large and one smaller current flat slab subduction segments exist along the Andean margin: the Peruvian, Pampean, and the Bucaramanga. Three Cenozoic flat slab segment are also known: Altiplano, Puna, and Payenia.

The Peruvian flat slab is located between the Gulf of Guayaquil (5 degrees S) and Arequipa (14 degrees S), extending ~1500 km along the strike of the subduction zone. The Peruvian flat slab is the largest in the world, [3] and extends ~700 km inboard from the trench axis. The subducting plate starts at a dip of 30 degrees then flattens out at a depth of 100 km under the Eastern Cordillera and Subandean zone. [30] The segment is visually correlated with the subduction of the Nazca Ridge, an aseismic ridge with thickened crust. The second highest zone in the Andes, Cordillera Blanca, is associated with the Peruvian flat slab segment and uplift of basement-cored blocks. Volcanism in the area ceased in the Late Miocene (11-5 Ma). Plate reconstructions time the collision of the Nazca Ridge with the subduction zone at 11.2 Ma at 11 degree S, which implies that the northern extent of the Peruvian flat slab may require some other subducted feature like an oceanic plateau. A putative subducted plateau, the Inca Plateau, has been argued for. [31]

The Pampean or Chilean flat slab segment is located between 27 degrees S and 33 degrees S, extending ~550 km along the strike of the subduction zone. The Pampean flat slab similarly extends ~700 km inboard from the trench axis. The segment is visually correlated with the Juan Fernandez Ridge, and the highest peak in the Andes, the non-volcanic Aconcagua (6961 m). This area has undergone the same "thick-skinned" deformation, leading to the high mountain peaks.

The Bucaramanga segment was recognized in early eighties from limited seismological evidence. [32] The segment is encompassed between 6 and 9 degrees N in Colombia, extending ~350 km along the strike of the subduction zone.

Other flat slabs

There are several other flat slab segments that warrant a mention: [3]

Economic geology

Subduction of thick oceanic crust could be linked with the metallogenesis of copper and gold deposits. [4] The 10 largest young (<18 Ma) gold deposits in South America are associated with flat slab segments. [4] Enhanced metallogenesis may be caused by the cessation of magmatism in the arc allowing the conservation of sulfur-rich volatiles. [4] The failure of the putative flat slab under western North America may have been vital in producing Carlin-type gold deposits. [33]

Early Earth subduction

Early Earth's mantle was hotter and it has been proposed that flat slab subduction was the dominant style. [34] Computer modeling has shown that an increase in oceanic plate buoyancy associated with enhanced oceanic crust production would have been counteracted by decreased mantle viscosity, so flat slab subduction would not have been dominant or non-existent. [10]

Related Research Articles

<span class="mw-page-title-main">Subduction</span> A geological process at convergent tectonic plate boundaries where one plate moves under the other

Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the heavier plate dives beneath the second plate and sinks into the mantle. A region where this process occurs is known as a subduction zone, and its surface expression is known as an arc-trench complex. The process of subduction has created most of the Earth's continental crust. Rates of subduction are typically measured in centimeters per year, with rates of convergence as high as 11 cm/year.

<span class="mw-page-title-main">Convergent boundary</span> Region of active deformation between colliding tectonic plates

A convergent boundary is an area on Earth where two or more lithospheric plates collide. One plate eventually slides beneath the other, a process known as subduction. The subduction zone can be defined by a plane where many earthquakes occur, called the Wadati–Benioff zone. These collisions happen on scales of millions to tens of millions of years and can lead to volcanism, earthquakes, orogenesis, destruction of lithosphere, and deformation. Convergent boundaries occur between oceanic-oceanic lithosphere, oceanic-continental lithosphere, and continental-continental lithosphere. The geologic features related to convergent boundaries vary depending on crust types.

<span class="mw-page-title-main">Island arc</span> Arc-shaped archipelago formed by intense seismic activity of long chains of active volcanoes

Island arcs are long chains of active volcanoes with intense seismic activity found along convergent tectonic plate boundaries. Most island arcs originate on oceanic crust and have resulted from the descent of the lithosphere into the mantle along the subduction zone. They are the principal way by which continental growth is achieved.

<span class="mw-page-title-main">Farallon Plate</span> Ancient oceanic plate that has mostly subducted under the North American Plate

The Farallon Plate was an ancient oceanic plate. It formed one of the three main plates of Panthalassa, alongside the Izanagi Plate and the Phoenix Plate, which were connected by a triple junction. The Farallon Plate began subducting under the west coast of the North American Plate—then located in modern Utah—as Pangaea broke apart and after the formation of the Pacific Plate at the centre of the triple junction during the Early Jurassic. It is named for the Farallon Islands, which are located just west of San Francisco, California.

<span class="mw-page-title-main">Explorer Plate</span> Oceanic tectonic plate beneath the Pacific Ocean off the west coast of Vancouver Island, Canada

The Explorer Plate is an oceanic tectonic plate beneath the Pacific Ocean off the west coast of Vancouver Island, Canada, which is partially subducted under the North American Plate. Along with the Juan de Fuca Plate and Gorda Plate, the Explorer Plate is a remnant of the ancient Farallon Plate, which has been subducted under the North American Plate. The Explorer Plate separated from the Juan de Fuca Plate roughly 4 million years ago. In its smoother, southern half, the average depth of the Explorer plate is roughly 2,400 metres (7,900 ft) and rises up in its northern half to a highly variable basin between 1,400 metres (4,600 ft) and 2,200 metres (7,200 ft) in depth.

<span class="mw-page-title-main">Forearc</span> The region between an oceanic trench and the associated volcanic arc

Forearc is a plate tectonic term referring to a region in a subduction zone between an oceanic trench and the associated volcanic arc. Forearc regions are present along convergent margins and eponymously form 'in front of' the volcanic arcs that are characteristic of convergent plate margins. A back-arc region is the companion region behind the volcanic arc.

<span class="mw-page-title-main">Volcanic arc</span> Chain of volcanoes formed above a subducting plate

A volcanic arc is a belt of volcanoes formed above a subducting oceanic tectonic plate, with the belt arranged in an arc shape as seen from above. Volcanic arcs typically parallel an oceanic trench, with the arc located further from the subducting plate than the trench. The oceanic plate is saturated with water, mostly in the form of hydrous minerals such as micas, amphiboles, and serpentines. As the oceanic plate is subducted, it is subjected to increasing pressure and temperature with increasing depth. The heat and pressure break down the hydrous minerals in the plate, releasing water into the overlying mantle. Volatiles such as water drastically lower the melting point of the mantle, causing some of the mantle to melt and form magma at depth under the overriding plate. The magma ascends to form an arc of volcanoes parallel to the subduction zone.

<span class="mw-page-title-main">Mendocino Triple Junction</span> Point where the Gorda plate, the North American plate, and the Pacific plate meet

The Mendocino Triple Junction (MTJ) is the point where the Gorda plate, the North American plate, and the Pacific plate meet, in the Pacific Ocean near Cape Mendocino in northern California. This triple junction is the location of a change in the broad plate motions which dominate the west coast of North America, linking convergence of the northern Cascadia subduction zone and translation of the southern San Andreas Fault system. This region can be characterized by transform fault movement, the San Andreas also by transform strike slip movement, and the Cascadia subduction zone by a convergent plate boundary subduction movement. The Gorda plate is subducting, towards N50ºE, under the North American plate at 2.5 – 3 cm/yr, and is simultaneously converging obliquely against the Pacific plate at a rate of 5 cm/yr in the direction N115ºE. The accommodation of this plate configuration results in a transform boundary along the Mendocino Fracture Zone, and a divergent boundary at the Gorda Ridge. This area is tectonically active historically and today. The Cascadia subduction zone is known to be capable of producing megathrust earthquakes on the order of MW 9.0.

<span class="mw-page-title-main">Andean Volcanic Belt</span> Volcanic belt in South America

The Andean Volcanic Belt is a major volcanic belt along the Andean cordillera in Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru. It is formed as a result of subduction of the Nazca Plate and Antarctic Plate underneath the South American Plate. The belt is subdivided into four main volcanic zones which are separated by volcanic gaps. The volcanoes of the belt are diverse in terms of activity style, products, and morphology. While some differences can be explained by which volcanic zone a volcano belongs to, there are significant differences within volcanic zones and even between neighboring volcanoes. Despite being a type location for calc-alkalic and subduction volcanism, the Andean Volcanic Belt has a broad range of volcano-tectonic settings, as it has rift systems and extensional zones, transpressional faults, subduction of mid-ocean ridges and seamount chains as well as a large range of crustal thicknesses and magma ascent paths and different amounts of crustal assimilations.

<span class="mw-page-title-main">Izu–Bonin–Mariana Arc</span> Convergent boundary in Micronesia

The Izu–Bonin–Mariana (IBM) arc system is a tectonic plate convergent boundary in Micronesia. The IBM arc system extends over 2800 km south from Tokyo, Japan, to beyond Guam, and includes the Izu Islands, the Bonin Islands, and the Mariana Islands; much more of the IBM arc system is submerged below sealevel. The IBM arc system lies along the eastern margin of the Philippine Sea Plate in the Western Pacific Ocean. It is the site of the deepest gash in Earth's solid surface, the Challenger Deep in the Mariana Trench.

<span class="mw-page-title-main">Juan Fernández Ridge</span> Volcanic island and seamount chain on the Nazca Plate

The Juan Fernández Ridge is a volcanic island and seamount chain on the Nazca Plate. It runs in a west–east direction from the Juan Fernández hotspot to the Peru–Chile Trench at a latitude of 33° S near Valparaíso. The Juan Fernández Islands are the only seamounts that reach the surface.

<span class="mw-page-title-main">Mariana Plate</span> Small tectonic plate west of the Mariana Trench

The Mariana Plate is a micro tectonic plate located west of the Mariana Trench which forms the basement of the Mariana Islands which form part of the Izu–Bonin–Mariana Arc. It is separated from the Philippine Sea Plate to the west by a divergent boundary with numerous transform fault offsets. The boundary between the Mariana and the Pacific Plate to the east is a subduction zone with the Pacific Plate subducting beneath the Mariana. This eastern subduction is divided into the Mariana Trench, which forms the southeastern boundary, and the Izu–Ogasawara Trench the northeastern boundary. The subduction plate motion is responsible for the shape of the Mariana plate and back arc.

<span class="mw-page-title-main">Nazca Ridge</span> Submarine ridge off the coast of Peru

The Nazca Ridge is a submarine ridge, located on the Nazca Plate off the west coast of South America. This plate and ridge are currently subducting under the South American Plate at a convergent boundary known as the Peru-Chile Trench at approximately 7.7 cm (3.0 in) per year. The Nazca Ridge began subducting obliquely to the collision margin at 11°S, approximately 11.2 Ma, and the current subduction location is 15°S. The ridge is composed of abnormally thick basaltic ocean crust, averaging 18 ±3 km thick. This crust is buoyant, resulting in flat slab subduction under Peru. This flat slab subduction has been associated with the uplift of Pisco Basin and the cessation of Andes volcanism and the uplift of the Fitzcarrald Arch on the South American continent approximately 4 Ma.

<span class="mw-page-title-main">Slab (geology)</span> The portion of a tectonic plate that is being subducted

In geology, the slab is a significant constituent of subduction zones.

<span class="mw-page-title-main">Subduction polarity reversal</span>

Subduction polarity reversal is a geologic process in which two converging plates switch roles: The over-lying plate becomes the down-going plate, and vice versa. There are two basic units which make up a subduction zone. This consists of an overriding plate and the subduction plate. Two plates move towards each other due to tectonic forces. The overriding plate will be on the top of the subducting plate. This type of tectonic interaction is found at many plate boundaries.

<span class="mw-page-title-main">Divergent double subduction</span> Special type of Tectonic process

Divergent double subduction, also called outward dipping double-sided subduction, is a special type of subduction process in which two parallel subduction zones with different directions are developed on the same oceanic plate. In conventional plate tectonics theory, an oceanic plate subducts under another plate and new oceanic crust is generated somewhere else, commonly along the other side of the same plates However, in divergent double subduction, the oceanic plate subducts on two sides. This results in the closure of ocean and arc–arc collision.

<span class="mw-page-title-main">Aleutian subduction zone</span> Convergence boundary between the North American Plate and the Pacific Plate

The Aleutian subduction zone is a 2,500 mi (4,000 km) long convergent boundary between the North American Plate and the Pacific Plate, that extends from the Alaska Range to the Kamchatka Peninsula. Here, the Pacific Plate is being subducted underneath the North American Plate and the rate of subduction changes from west to east from 7.5 to 5.1 cm per year. The Aleutian subduction zone includes two prominent features, the Aleutian Arc and the Aleutian Trench. The Aleutian Arc was created via volcanic eruptions from dehydration of the subducting slab at ~100 km depth. The Aleutian Trench is a narrow and deep morphology that occurs between the two converging plates as the subducting slab dives beneath the overriding plate.

Ridge push is a proposed driving force for plate motion in plate tectonics that occurs at mid-ocean ridges as the result of the rigid lithosphere sliding down the hot, raised asthenosphere below mid-ocean ridges. Although it is called ridge push, the term is somewhat misleading; it is actually a body force that acts throughout an ocean plate, not just at the ridge, as a result of gravitational pull. The name comes from earlier models of plate tectonics in which ridge push was primarily ascribed to upwelling magma at mid-ocean ridges pushing or wedging the plates apart.

<span class="mw-page-title-main">Oblique subduction</span> Tectonic process

Oblique subduction is a form of subduction for which the convergence direction differs from 90° to the plate boundary. Most convergent boundaries involve oblique subduction, particularly in the Ring of Fire including the Ryukyu, Aleutian, Central America and Chile subduction zones. In general, the obliquity angle is between 15° and 30°. Subduction zones with high obliquity angles include Sunda trench and Ryukyu arc.

<span class="mw-page-title-main">Chile Ridge</span> Submarine oceanic ridge in the Pacific Ocean

The Chile Ridge, also known as the Chile Rise, is a submarine oceanic ridge formed by the divergent plate boundary between the Nazca Plate and the Antarctic Plate. It extends from the triple junction of the Nazca, Pacific, and Antarctic plates to the Southern coast of Chile. The Chile Ridge is easy to recognize on the map, as the ridge is divided into several segmented fracture zones which are perpendicular to the ridge segments, showing an orthogonal shape toward the spreading direction. The total length of the ridge segments is about 550–600 km.

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  15. ↑ Pennington, Wayne D. (1984-02-20). "Geodynamics of Back-Arc Regions The effect of oceanic crustal structure on phase changes and subduction". Tectonophysics. 102 (1): 377–398. doi:10.1016/0040-1951(84)90023-4.
  16. 1 2 3 Alvarado, Patricia; Pardo, Mario; Gilbert, Hersh; Miranda, Silvia; Anderson, Megan; Saez, Mauro; Beck, Susan (2009-06-01). Flat-slab subduction and crustal models for the seismically active Sierras Pampeanas region of Argentina. Vol. 204. pp. 261–278. doi:10.1130/2009.1204(12). ISBN   9780813712048. ISSN   0072-1069.{{cite book}}: |journal= ignored (help)
  17. 1 2 3 Gutscher, Marc-André; Maury, René; Eissen, Jean-Philippe; Bourdon, Erwan (2000-06-01). "Can slab melting be caused by flat subduction?". Geology. 28 (6): 535–538. Bibcode:2000Geo....28..535G. doi:10.1130/0091-7613(2000)28<535:csmbcb>2.0.co;2. ISSN   0091-7613.
  18. 1 2 Humphreys, Eugene (2009-06-01). "Relation of flat subduction to magmatism and deformation in the western United States". Backbone of the Americas: Shallow Subduction, Plateau Uplift, and Ridge and Terrane Collision. Vol. 204. pp. 85–98. doi:10.1130/2009.1204(04). ISBN   9780813712048. ISSN   0072-1069.{{cite book}}: |journal= ignored (help)
  19. ↑ Gutscher, M. -A; Malavieille, J; Lallemand, S; Collot, J. -Y (1999-05-15). "Tectonic segmentation of the North Andean margin: impact of the Carnegie Ridge collision". Earth and Planetary Science Letters. 168 (3–4): 255–270. Bibcode:1999E&PSL.168..255G. doi:10.1016/S0012-821X(99)00060-6.
  20. ↑ Litvak, Vanesa D.; Poma, Stella; Kay, Suzanne Mahlburg (2007-09-01). "Paleogene and Neogene magmatism in the Valle del Cura region: New perspective on the evolution of the Pampean flat slab, San Juan province, Argentina". Journal of South American Earth Sciences. 24 (2–4): 117–137. Bibcode:2007JSAES..24..117L. doi:10.1016/j.jsames.2007.04.002. hdl: 11336/77992 .
  21. 1 2 Jordan, T. E.; Allmendinger, R. W. (1986). "Sign In". American Journal of Science. 286 (10): 737–764. doi: 10.2475/ajs.286.10.737 .
  22. ↑ Cahill, Thomas; Isacks, Bryan L. (1986-04-01). "An apparent double-planed Benioff Zone beneath northern Chile resulting from misidentification of reflected phases". Geophysical Research Letters. 13 (4): 333–336. Bibcode:1986GeoRL..13..333C. doi:10.1029/GL013i004p00333. ISSN   1944-8007.
  23. ↑ Espurt, N.; Baby, P.; Brusset, S.; Roddaz, M.; Hermoza, W.; Regard, V.; Antoine, P.-O.; Salas-Gismondi, R.; Bolaños, R. (2007-06-01). "How does the Nazca Ridge subduction influence the modern Amazonian foreland basin?". Geology. 35 (6): 515–518. Bibcode:2007Geo....35..515E. doi:10.1130/G23237A.1. ISSN   0091-7613.
  24. ↑ Baby, P.; Guyot, J. L.; Deniaud, Y.; Zubieta, D.; Christophoul, F.; Rivadeneira, M.; Jara, F. (1999-01-01). "The High Amazonian Basin: tectonic control and mass balance" (PDF). International Symposium MANAUS 99, Hydrological and Geochemical Process in Large-scale Rivers Basins: Manaus (Brazil).
  25. ↑ Kronberg, B.I.; Fralick, P.W.; Benchimol, R.E. (1998-09-01). "Late Quaternary sedimentation and palaeohydrology in the Acre foreland basin, SW Amazonia". Basin Research. 10 (3): 311. Bibcode:1998BasR...10..311K. doi:10.1046/j.1365-2117.1998.00067.x. ISSN   1365-2117. S2CID   140183791.
  26. 1 2 Gutscher, Marc-André (2002-04-01). "Andean subduction styles and their effect on thermal structure and interplate coupling". Journal of South American Earth Sciences. Flat-Slab Subduction in the Andes. 15 (1): 3–10. Bibcode:2002JSAES..15....3G. doi:10.1016/S0895-9811(02)00002-0.
  27. ↑ Spencer, Jon E. (1994-01-01). "A numerical assessment of slab strength during high-and low-angle subduction and implications for Laramide orogenesis". Journal of Geophysical Research: Solid Earth. 99 (B5): 9227–9236. Bibcode:1994JGR....99.9227S. doi:10.1029/94jb00503.
  28. ↑ Ramos, Victor A.; Folguera, Andrés (2009-01-01). "Andean flat-slab subduction through time". Geological Society, London, Special Publications. 327 (1): 31–54. Bibcode:2009GSLSP.327...31R. doi:10.1144/SP327.3. ISSN   0305-8719. S2CID   43604314.
  29. ↑ Barazangi, Muawia; Isacks, Bryan L. (1976-11-01). "Spatial distribution of earthquakes and subduction of the Nazca plate beneath South America". Geology. 4 (11): 686–692. Bibcode:1976Geo.....4..686B. doi:10.1130/0091-7613(1976)4<686:sdoeas>2.0.co;2. ISSN   0091-7613.
  30. ↑ Dorbath, L.; Dorbath, C.; Jimenez, E.; Rivera, L. (1991-01-01). "Seismicity and tectonic deformation in the Eastern Cordillera and the sub-Andean zone of central Peru" (PDF). Journal of South American Earth Sciences. 4 (1): 13–24. Bibcode:1991JSAES...4...13D. doi:10.1016/0895-9811(91)90015-D.
  31. ↑ Gutscher, M. -A.; Olivet, J. -L.; Aslanian, D.; Eissen, J. -P.; Maury, R. (1999-09-15). "The "lost inca plateau": cause of flat subduction beneath peru?". Earth and Planetary Science Letters. 171 (3): 335–341. Bibcode:1999E&PSL.171..335G. doi:10.1016/S0012-821X(99)00153-3.
  32. ↑ Pennington, Wayne D. (1981-11-10). "Subduction of the Eastern Panama Basin and seismotectonics of northwestern South America". Journal of Geophysical Research: Solid Earth. 86 (B11): 10753–10770. Bibcode:1981JGR....8610753P. doi: 10.1029/JB086iB11p10753 . ISSN   2156-2202.
  33. ↑ Muntean, John L.; Cline, Jean S.; Simon, Adam C.; Longo, Anthony A. (2011-02-01). "Magmatic-hydrothermal origin of Nevada/'s Carlin-type gold deposits". Nature Geoscience. 4 (2): 122–127. Bibcode:2011NatGe...4..122M. doi:10.1038/ngeo1064. ISSN   1752-0894.
  34. ↑ Abbott, Dallas; Drury, Rebecca; Smith, Walter H. F. (1994-10-01). "Flat to steep transition in subduction style". Geology. 22 (10): 937–940. Bibcode:1994Geo....22..937A. doi:10.1130/0091-7613(1994)022<0937:ftstis>2.3.co;2. ISSN   0091-7613.
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