Active thrusting in the inner forearc of an erosive convergent margin, Pacific coast, Costa Rica

Fisher, Donald M.; Gardner, Thomas W.; Sak, Peter B.; Sanchez, Joanna D.; Murphy, Katherine R.; Vannucchi, Paola

doi:10.1029/2002tc001464

Cited by 80 publications

(193 citation statements)

References 52 publications

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“…In particular, with corrections for elastic strain along the subduction zone, LaFemina et al [2009] show 25 AE 5 mm/yr of shortening across the region above sea level. Although the geologic bounds on Quaternary shortening, 10-40 mm/yr [Fisher et al, 2004;Sitchler et al, 2007] are less precisely constrained than those based on GPS measurements, they support the evidence for rapid shortening.…”

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confidence: 50%

“…[71] Talamanca Cordillera (Costa Rica) (TCR): We rely on both GPS measurements [LaFemina et al, 2009;Norabuena et al, 2004] and slip rates on faults active in Quaternary time [Fisher et al, 2004;Sitchler et al, 2007]. In particular, with corrections for elastic strain along the subduction zone, LaFemina et al [2009] show 25 AE 5 mm/yr of shortening across the region above sea level.…”

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confidence: 99%

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Tectonics, climate, and mountain topography

et al. 2012

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[1] By regressing simple, independent variables that describe climate and tectonic processes against measures of topography and relief of 69 mountain ranges worldwide, we quantify the relative importance of these processes in shaping observed landscapes. Climate variables include latitude (as a surrogate for mean annual temperature and insolation, but most importantly for the likelihood of glaciation) and mean annual precipitation. To quantify tectonics we use shortening rates across each range. As a measure of topography, we use mean and maximum elevations and relief calculated over different length scales. We show that the combination of climate (negative correlation) and tectonics (positive correlation) explain substantial fractions (>25%, but <50%) of mean and maximum elevations of mountain ranges, but that shortening rates account for smaller portions, <25%, of the variance in most measures of topography and relief (i.e., with low correlations and large scatter). Relief is insensitive to mean annual precipitation, but does depend on latitude, especially for relief calculated over small ($1 km) length scales, which we infer to reflect the importance of glacial erosion. Larger-scale (averaged over length scales of $10 km) relief, however, correlates positively with tectonic shortening rate. Moreover, the ratio between small-scale and large-scale relief, as well as the relative relief (the relief normalized by the mean elevation of the region) varies most strongly with latitude (strong positive correlation). Therefore, the location of a mountain range on Earth with its corresponding climatic conditions, not just tectonic forcing, appears to be a key factor in determining its shape and size. In any case, the combination of tectonics and climate, as quantified here, can account for approximately half of the variance in these measures of topography. The failure of present-day shortening rates to account for more than 25% of most measures of relief raises the question: Is active tectonics overrated in attempts to account for present-day relief and exhumation rates of high terrain?

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confidence: 99%

Tectonics, climate, and mountain topography

et al. 2012

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“…The 60 -25 Ma Quepos and Osa terrains, in fact, are interpreted to reflect rocks accreted from subducted edifices generated by the Galapagos hot spot [Hauff et al, 1997[Hauff et al, , 2000 (Figures 1a and 2). Crucially there is no evidence that the Costa Rican forearc is composed of an accretionary complex of tectonized sediments offscraped from the currently subducting plate Vannucchi et al, 2001;Fisher et al, 2004]. Plate reconstructions indicate that the Cocos-Nazca-Caribbean triple junction migrates to the southeast at a rate of $50 km/Myr, implying that the Nazca plate was subducting beneath southeast Costa Rica in the late Neogene [Gardner et al, 1992].…”

Section: Tectonic Setting and Previous Studymentioning

confidence: 99%

“…The extent to which right-lateral slip along the Panama Fracture Zone produces strike-slip deformation in the upper plate is ambiguous. Fisher et al [2004] demonstrated that strikeslip motion in the upper plate parallel to the margin is not consistent with the geometry of fault-related folds in the Fila Costeña. GPS measurements, moreover, indicate a stress regime with the maximum compression axis perpendicular to the coast [Dixon, 2003;Norabuena et al, 2004].…”

Section: The Osa Mélangementioning

confidence: 99%

“…The seismically active slab dips at $65°near the Nicaraguan border and shallows to a few degrees inboard of the Cocos Ridge. When the Cocos Ridge arrived at the Middle America Trench is a debated issue, with estimates ranging from $1 Ma [Lonsdale and Klitgord, 1978;Gardner et al, 1992;Fisher et al, 2004] to $ 5 Ma [De Boer et al, 1995;Grafe et al, 2002;Vannucchi et al, 2003;MacMillan et al, 2004] to $8 Ma [Rivier, 1985;Abratis and Worner, 2001] (Figure 2). …”

Section: Tectonic Setting and Previous Studymentioning

confidence: 99%

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From seamount accretion to tectonic erosion: Formation of Osa Mélange and the effects of Cocos Ridge subduction in southern Costa Rica

Vannucchi¹,

et al. 2006

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The Costa Rica portion of the Middle America Trench (MAT) is characterized by active tectonic erosion, a process that causes the removal of material from the base of the upper plate as the plate boundary migrates upward. Offshore studies demonstrate accelerated subduction erosion starting at the Miocene‐Pliocene boundary, as the result of subduction of thickened Galapagos related crust, as presently represented by the Cocos Ridge. The subduction of the Cocos Ridge also caused uplift and exposure of the outer forearc on the Osa Peninsula, which offers a window to explore the tectonic evolution of the area. The rocks outcropping on Osa Peninsula are a middle Eocene–middle Miocene mélange dominated by basalt, chert, and limestone resulting from accretion of seamounts. The accretion‐dominated period of the MAT evolution ended at the Miocene‐Pliocene boundary, when thickened crust, a paleo‐Cocos Ridge, produced at the Galapagos hot spot arrived at the trench. The thick crust caused uplift and severe tectonic erosion of the accretionary edifice allowing exhumation of the Osa Mélange. The change from accretion to erosion caused the outer forearc to be offset along subvertical faults that define small (kilometer to tens of kilometers size) blocks that are going through differential vertical movements in response to the morphology of the subducting ridge. Subduction accretion and erosion are two processes that can alternate in time and space or coexist along the same margin, so that mass removal can develop on a previously growing margin and completely remove an accretionary prism.

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Rock uplift and exhumation of continental margins by the collision, accretion, and subduction of buoyant and topographically prominent oceanic crust

Spikings

Simpson

2014

Tectonics

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Understanding the causes of rock and surface uplift is important because they control the location of mountain building, depocenters, and drainage characteristics and can influence climate. Here we combine previous thermochronological data with field observations to determine the amount of exhumation, rock, and surface uplift that occurs in the upper plate of Central and South American subduction zones during the collision, accretion, and subduction of oceanic plateaus and aseismic ridges. The collision of buoyant and topographically prominent oceanic plateaus and ridges can drive at least 5 km of rock uplift within 2 Ma. Uplift appears to be an immediate response to collision and is generally independent of the slab dip. The amount of rock uplift is controlled mainly by excess topography associated with the ridge (ultimately linked to buoyancy) and erosion, while it is also influenced by the strength of the subduction interface related to the presence of volcanic asperities and overpressured sediments in the subduction channel. The quantity of exhumation is strongly dependant on climate-induced erosion and the lifespan over which the topography is uplifted and supported. Sediment draining into the trench may leave the elevated ridge axis sediment starved, increasing the shear stresses at the ridge subduction interface, leading to positive feedback between ridge subduction, rock uplift, and exhumation. Trench-parallel variations in exhumation have a direct impact on exploration paradigms for porphyry-related metalliferous deposits, and it is likely that porphyry systems are completely eroded by the impingement of plateaus and aseismic ridges within temperate and tropical climates.

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Active thrusting in the inner forearc of an erosive convergent margin, Pacific coast, Costa Rica

Cited by 80 publications

References 52 publications

Tectonics, climate, and mountain topography

Tectonics, climate, and mountain topography

From seamount accretion to tectonic erosion: Formation of Osa Mélange and the effects of Cocos Ridge subduction in southern Costa Rica

Rock uplift and exhumation of continental margins by the collision, accretion, and subduction of buoyant and topographically prominent oceanic crust

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