Quaternary uplift astride the aseismic Cocos Ridge, Pacific coast, Costa Rica

Gardner, Thomas W.; Verdonck, David; Pinter, Nicholas; Slingerland, Rudy; Furlong, Kevin P.; Bullard, Thomas F.; Wells, Stephen

doi:10.1130/0016-7606(1992)104<0219:quatac>2.3.co;2

Cited by 155 publications

(253 citation statements)

References 0 publications

Supporting

Mentioning

233

Contrasting

Unclassified

Order By: Relevance

“…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]. Arc volcanism and the presence of an accretionary prism in southwest Panama are consistent with active subduction of the Nazca plate to the southeast of the triple junction.…”

Section: Tectonic Setting and Previous Studymentioning

confidence: 99%

“…Our findings do not support either of these interpretations and rather point to a tectonic mélange that was accreted prior to the arrival of the Cocos Ridge during subduction, underthrusting and tectonic burial of seamounts and seamounts chains. The evidence for active, recent tectonic erosion of the forearc is compelling , and Osa Mélange does not reflect accretion from the currently subducting plate, given the southeastward migration of the Cocos-Nazca-Caribbean triple junction over the last 5 Myr [Hey, 1977;Gardner et al, 1992;MacMillan et al, 2004], possible transform jumps [Lonsdale and Klitgord, 1978;Lowrie et al, 1979], and the subduction of the Cocos Ridge .…”

Section: Introductionmentioning

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%

“…The Marenco Formation has been used to interpret the response of the upper plate to the subduction of the Cocos Ridge . Late Pleistocene to Holocene sediment also outcrop extensively on top of the Osa Group along the southeasternmost part of the peninsula, where they have been referred to as the Puerto Jiménez Group [Berrangé, 1989] and also used to document a net vertical uplift and landward block rotation of the Osa Peninsula [Gardner et al, 1992].…”

Section: Plio-quaternary Sedimentationmentioning

confidence: 99%

“…However, on Osa Peninsula (Figure 1a), along the erosive plate boundary of the Middle America Trench (MAT) in Costa Rica Vannucchi et al, 2001Vannucchi et al, , 2004, the outermost fore arc is exposed, providing a window into the tectonic evolution of the area. The greatest uplift and unroofing is occurring in the region inboard of prominent bathymetric highs on the subducting plate, most notably the Cocos Ridge [Gardner et al, 1992;Fisher et al, 1998] (Figure 1a). Directly inboard of the Cocos Ridge, the outer forearc is composed of a disrupted rock body known as the Osa Mélange [Di Marco et al, 1995] (Figure 1b).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

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

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Section: Tectonic Setting and Previous Studymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Tectonic Setting and Previous Studymentioning

confidence: 99%

Section: Plio-quaternary Sedimentationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

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

Self Cite

View full text Add to dashboard Cite

show abstract

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

Spikings

Simpson

2014

Tectonics

View full text Add to dashboard Cite

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.

show abstract

Fluid accumulation along the Costa Rica subduction thrust and development of the seismogenic zone

et al. 2015

View full text Add to dashboard Cite

In 2011 we acquired an 11 × 55 km, 3-D seismic reflection volume across the Costa Rica margin, NW of the Osa Peninsula, to accurately image the subduction thrust in 3-D, to examine fault zone properties, and to infer the hydrogeology that controls fluid accumulation along the thrust. Following processing to remove water column multiples, noise, and acquisition artifacts, we constructed a 3-D seismic velocity model for Kirchhoff prestack depth migration imaging. Images of the plate boundary thrust show high-reflection amplitudes underneath the middle to lower slope that we attribute to fluid-rich, poorly drained portions of the subduction thrust. At~5 km subseafloor, beneath the upper slope, the plate interface abruptly becomes weakly reflective, which we interpret as a transition to a well-drained subduction thrust. Mineral dehydration during diagenesis may also diminish at 5 km subseafloor to reduce fluid production and contribute to the downdip change from high to low amplitude. There is also a layered fabric and systems of both thrust and normal faults within the overriding plate that form a "plumbing system." Faults commonly have fault plane reflections and are presumably fluid charged. The faults and layered fabric form three compartmentalized hydrogeologic zones: (1) a shallow NE dipping zone beneath the slope, (2) a steeply SW dipping zone beneath the shelf slope break, and (3) a NE dipping zone beneath the shelf. The more direct pathway in the middle zone drains the subduction thrust more efficiently and contributes to reduced fluid pressure, elevates effective stress, and creates greater potential for unstable coseismic slip.

show abstract

Quaternary uplift astride the aseismic Cocos Ridge, Pacific coast, Costa Rica

Cited by 155 publications

References 0 publications

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

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

Fluid accumulation along the Costa Rica subduction thrust and development of the seismogenic zone

Contact Info

Product

Resources

About