Anatomy of an Evolving Island Arc: Tectonic and Eustatic Control in the South Central American Fore‐Arc Area

Seyfried, Hartmut; Astorga, Allan; Amann, Hubert; Calvo, Claudio; Kolb, Wolfgang; Schmidt, Hannelore; Winsemann, Jutta

doi:10.1002/9781444303896.ch13

Cited by 22 publications

(51 citation statements)

References 22 publications

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“…At the seaward edge of the shelf the development of the margin wedge occurred in Paleogene time (Eocene?) when the shelf basin formed and the Nicoya area was uplifted from deep water [Seyfried et al, 1991;Winsemann, 1994]. Although the slope sediment thins seaward, there is little evidence that can be used to estimate a progressively younger age in a seaward direction.…”

Section: Discussionmentioning

confidence: 99%

Tectonic structure of the convergent Pacific margin offshore Costa Rica from multichannel seismic reflection data

Hinz¹,

Huene²,

Ranero³

1996

Tectonics

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Abstract. The Middle America Trench between the Cocos Ridge and a well-studied corridor off the Nicoya Peninsula has a more varied morphology and structure than previously reported. The morphological positive features on the lower plate significantly affect the upper plate structure. The Cocos Ridge has uplifted the margin opposite the Osa Peninsula. Northwest of Cocos Ridge, numerous seamounts on the oceanic crust sculptured the margin as they subducted. A seamount and a huge slump in the trench axis that currently block lateral sediment transport affect the sediment currently accreted and subducted. The greater portion of the trench sediment is subducted beneath a lower slope accretionary mass. Beneath the middle and upper slope is a margin wedge consisting of a high-velocity rock with few internal reflections. Its upper surface has a nondirectional random relief commonly 500 m high in the middle slope area. Overlying this surface is a low-velocity cover of slope sediment which shows little transgressive stratigraphy and can be traced landward into an inferred Eocene section beneath the shelf. The shelf basement is composed of Nicoya complex (ophiolite) with the same acoustic velocity, similar structure, and no apparent dividing geologic boundary with the margin wedge. We favor a seaward continuation of the Nicoya complex to the middle slope and emphasize the evidence for a non-steady state Tertiary tectonic history.

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Section: Discussionmentioning

confidence: 99%

Tectonic structure of the convergent Pacific margin offshore Costa Rica from multichannel seismic reflection data

Hinz¹,

Huene²,

Ranero³

1996

Tectonics

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“…b An orocline is an initially straight fold-andthrust belt that was later bent. c Primary arc and d Piedmont glacier (after HINDLE and BURKHARD 1999 SEYFRIED et al 1991;AMANN 1993;BOWLAND 1993;VON EYNATTEN et al 1993;CAMPOS 2001;BRANDES et al 2007a, b, c) and offshore geophysics (RANERO and VON HUENE 2000;BARCKHAUSEN et al 2003) but detailed knowledge of the back-arc area and the related fold-and-thrust belts is still limited. Southern Central America is characterized by the northeastward subduction of the Cocos Plate.…”

Section: Geological Settingmentioning

confidence: 99%

“…The Costa Rican part of the island arc can be subdivided into a northern and a southern arc segment (SEYFRIED et al 1991). The southern Costa Rican arc segment is influenced by flat subduction of the Cocos Ridge (CORRIGAN et al 1990;GARDNER et al 2013), which results in deformation and uplift on the upper-plate forearc (MORELL et al 2008(MORELL et al , 2012 (Fig.…”

Section: Introductionmentioning

confidence: 99%

Kinematic 3-D Retro-Modeling of an Orogenic Bend in the South Limón Fold-and-Thrust Belt, Eastern Costa Rica: Prediction of the Incremental Internal Strain Distribution

Brandes

Tanner

Winsemann

2016

Pure Appl. Geophys.

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The South Limón fold-and-thrust belt, in the backarc area of southern Costa Rica, is characterized by a 90°curvature of the strike of the thrust planes and is therefore a natural laboratory for the analysis of curved orogens. The analysis of curved foldand-thrust belts is a challenge because of the varying structural orientations within the belt. Based on seismic reflection lines, we created a 3-D subsurface model containing three major thrust faults and three stratigraphic horizons. 3-D kinematic retro-deformation modeling was carried out to analyze the spatial evolution of the fold-and-thrust belt. The maximum amount of displacement on each of the faults is (from hinterland to foreland); thrust 1: 800 m; thrust 2: 600 m; thrust 3: 250 m. The model was restored sequentially to its pre-deformational state. The strain history of the stratigraphic horizons in the model was calculated at every step. This shows that the internal strain pattern has an abrupt change at the orogenic bend. Contractional strain occurs in the forelimbs of the hanging-wall anticlines, while a zone of dilative strain spreads from the anticline crests to the backlimbs. The modeling shows that a NNE-directed transport direction best explains the structural evolution of the bend. This would require a left-lateral strike-slip zone in the North to compensate for the movement and thereby decoupling the South Limón fold-and-thrust belt from northern Costa Rica. Therefore, our modeling supports the presence of the Trans-Isthmic fault system, at least during the Plio-Pleistocene.

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“…The rapid opening of the North Atlantic Ocean, however, opened connections such as the Denmark strait, thus allowing Arctic water to overflow and to contribute further to the development of the psychrosphere. The trigger for northern hemisphere glaciation was the closure of the Isthmus of Panamfi between 4.2 and 2.4 million years ago (Keller et al, 1989), caused by the growth of the south Central American island arc system and its drift into the gap between Colombia and northern Nicaragua (Seyfried et al, 1991). The closure initiated the formation of a convection cell in the north eastern Caribbean, which until today drives the Gulf Stream, bringing warm water towards the north and with it the moisture necessary for the glaciation of Greenland, the Baltic shield and the Arctic Sea.…”

Section: The Cenozoic Icehouse Episode or How Many Roundabouts Creatementioning

confidence: 99%

Sea level change: a philosophical approach

Leinfelder

Seyfried

1993

Geol Rundsch

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The present Cenozoic era is an 'icehouse' episode characterized by a low sea level. Since the beginning of the industrial revolution, the human race has been emitting greenhouse gases, increasing the global atmospheric temperature, and causing a rise in sea level. If emissions continue to increase at the present rate, average global temperatures may rise by 1.5 °C by the year 2050, accompanied by a rise of about 30 cm in sea level. However, the prediction of future climatic conditions and sea level is hampered by the difficulty in modelling the interactions between the lithosphere, kryosphere, biosphere and atmosphere; in addition, the buffering capacity of our planet is still poorly understood. As scientists cannot offer unambiguous answers to simple questions, sorcerer's apprentices fill in the gaps, presenting plans to save planet without inconveniencing us.The geological record can help us to learn about the regulation mechanisms of our planet, many of which are connected with or expressed as sea level changes. Global changes in sea level are either tectono-eustatic or glacioeustatic. Plate tectonic processes strongly control sea levels and climate in the long term. There is a strong feed-back mechanism between sea level and climate; both can influence and determine each other. Although high sea levels are a powerful climatic buffer, falling sea levels accelerate climatic accentuation, the growth of the polar ice caps and will hence amplify the drop in sea level. Important sources of fossil greenhouse gases are botanic CO2 production, CO2 released by volcanic activity, and water vapour. The latter is particularly important when the surface area of the sea increases during a rise in sea level ('maritime greenhouse effect'). A 'volcanogenic greenhouse effect' (release of volcanogenic CO2) is possibly not equally important, as intense volcanic activity may take place both during icehouse episodes as well as during greenhouse episodes. The hydrosphere, land vegetation and carbonate platforms are major CO2 buffers which may both take up and release CO2. CO2 can be released from the ocean due to changes in the pCO 2 caused by growth of coral reefs and by uptake of CO2-rich freshwater from karst provinces. Efficient sinks of CO2 are the weathering products of silicate rocks; long-term sinks are organic deposits caused by regional anoxic events which preferrably develop during sea level rises and highstands; and coal-bearing strata. Deposition of limestone also removes CO2 from the atmospherichydrospheric cycle at a long term. Biotic crises are often related to either sea-level lows or sea-level highs. Long-term sea-level lows, characteristic of glacial periods, indicate cooling as major cause of extinction. During verly long-lasting greenhouse episodes the sea level is very high, climate and circulation systems are stable and biotic crises often develop as a consequence of oxygen depletion. On land, niche-splitting, complex food web structures and general overspecialization of biota will occur. Whether the crisis is...

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Anatomy of an Evolving Island Arc: Tectonic and Eustatic Control in the South Central American Fore‐Arc Area

Cited by 22 publications

References 22 publications

Tectonic structure of the convergent Pacific margin offshore Costa Rica from multichannel seismic reflection data

Tectonic structure of the convergent Pacific margin offshore Costa Rica from multichannel seismic reflection data

Kinematic 3-D Retro-Modeling of an Orogenic Bend in the South Limón Fold-and-Thrust Belt, Eastern Costa Rica: Prediction of the Incremental Internal Strain Distribution

Sea level change: a philosophical approach

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