Continental growth at convergent margins facing large ocean basins: a case study from Mesozoic convergent-margin basins of Baja California, Mexico

Busby, Cathy J.

doi:10.1016/j.tecto.2004.04.017

Cited by 95 publications

(70 citation statements)

References 52 publications

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“…It suggests that terrigenous materials present in MC were derived from mafic to felsic source rocks. Furthermore, our results are consistent with the Cretaceous geology of Baja California (Suárez-Vidal, 1987;Busby, 2004).…”

Section: Possible Source Of Rees In the Alisitos Formationsupporting

confidence: 88%

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Untitled

2017

Rev. Mex. Cien. Geol.

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Petrography, stable carbon and oxygen isotopes, and major, trace, and rare earth elements geochemistry of limestones of the Alisitos Formation in the Los Torotes, Baja California were studied in order to document the elemental variations among Member C (MC) and Member E (ME) of the formation and to understand their diagenetic and depositional conditions. The major petrographic types identified are mudstone, wackestone and packstone. The limestones of the Alisitos Formation show significant variations in δ 13 C and δ 18O values (+4.13 to +5.26‰; -14.17 to -6.84‰; respectively). The limestones from Member C (MC) show higher ΣREE content (23 ± 17, n=10) than Member E (ME) (11 ± 5.5, n=9) of the Alisitos Formation. The observed variations in ΣREE content in these limestones are due to the amount of detrital material present in them. The limestones from ME record seawater-like REE+Y patterns, whereas the MC records non-seawater-like signatures (i.e. significant enrichment of middle rare earth elements: MREE). Most of the analyzed samples from the Alisitos Formation show negative Ce anomalies (Ce/Ce*: 0.67 -0.99, n=17). The limestones show both negative and positive Eu anomalies (Eu/Eu*: 0.58 -2.91, n=19). The positive Eu anomalies identified in many samples may be due to the influence of hydrothermal fluids or co-precipitation of hydrothermal Fe-sulfide. The limestones of ME exhibit seawater-like-REE patterns suggesting that most of the REEs present in them were derived from seawater. However, the limestones of MC were contaminated by detrital materials which effectively mask the seawater-like signatures. The detrital materials present in the limestones of MC were probably derived from the mafic to felsic source rocks.

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Section: Possible Source Of Rees In the Alisitos Formationsupporting

confidence: 88%

“…The Alisitos Formation was derived from a volcanoplutonic arc developed along the western margin of Baja California during the Early Cretaceous (ca. 140-100 Ma; Busby 2004). The Alisitos Formation is estimated to be about 6,000 to 7,500 m thick and spans from at least Aptian to Albian in age (Allison, 1974;Wetmore et al, 2005).…”

Section: Geology and Stratigraphymentioning

confidence: 99%

Untitled

2017

Rev. Mex. Cien. Geol.

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“…Whatever form it takes, and whether observed or not, the contact is considered by most workers to represent a suture zone related to either a closed marginal basin or a collision in a doubly eastward-dipping subduction model (Todd et al 1988;Johnson et al 1999b;Busby 2004;Lee et al 2007;Schmidt et al 2014;Wetmore et al 2014;Shaw et al 2014). Only Dickinson and Lawton (2001a) and a French group (Tardy et al 1992(Tardy et al , 1994 proposed westward-dipping subduction models.…”

Section: Geological Settingmentioning

confidence: 99%

“…Primordial mantle-normalizing values are from McDonough (1989). Spera 1988b;Busby 2004Busby , 2012. Modern examples include the Cascades, where the volcanoes sit in a half graben (Williams and McBirney 1979;Mooney and Weaver 1989), the lowstanding Alaskan Peninsula (Burk 1965;Fliedner and Klemperer 2000) where volcanoes such as Augustine are partially submerged in Cook Inlet (Power et al 2010), the Kamchatka Peninsula of easternmost Russia where towering stratovolcanoes sit in huge faultbounded troughs (Erlich 1968(Erlich , 1979Levin et al 2002a, b), to New Zealand where the Taupo zone sector of the arc is actively extending as calderas and stratocones erupt within it (Houghton et al 1991;Harrison and White 2006;Downs et al 2014), and the Central American arc where volcanoes are aligned in a long linear depression (Williams et al 1964;Williams and McBirney 1969;Burkhart and Self 1985;MacKenzie et al 2008).…”

Section: Arcsmentioning

confidence: 99%

“…1), our understanding of Cordilleran batholiths has barely progressed since the late 1960s, largely because most workers still follow Hamilton's original concept that the Sierran and Peninsular Ranges batholiths were built entirely by eastward subduction of oceanic lithosphere beneath the western margin of the Americas (Todd et al 1988Walawender et al 1990; Kimbrough et al 2001Kimbrough et al , 2014aDucea 2001;Schmidt et al , 2009Grove et al 2003;Tulloch and Kimbrough 2003;Wetmore et al 2003;Busby 2004;Lee et al 2007;Gehrels et al 2009;DeCelles et al 2009;Paterson et al 2012;Kimbrough et al 2014a;Shaw et al 2014). In this paradigm, two subvariant models, both with eastward-directed subduction, dominate the discussion: (1) the younger, more siliceous and potassic easterly plutons are related to, and thus document, progressive shallowing of eastward subducting oceanic lithosphere with or without subduction of the older arc and forearc sediments; or (2) the western sector was separated from the eastern sector by a narrow back-arc basin, and following closure, subduction-related magmatism simply continued to produce the eastern sector of the batholiths.…”

Section: Introductionmentioning

confidence: 99%

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Arc and Slab-Failure Magmatism in Cordilleran Batholiths II – The Cretaceous Peninsular Ranges Batholith of Southern and Baja California

Hildebrand

Whalen

2014

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Ever since the late 1960s when Warren Hamilton proposed that the great Cordilleran batholiths of the western Americas are the roots of volcanic arcs like the Andes and were generated by longstanding eastward subduction, most geologists have followed suit, despite the evergrowing recognition that many Cordilleran batholiths are complex, composite bodies that developed with intervals of intense shortening and exhumation between and during periods of magmatism. The Peninsular Ranges batholith of Southern and Baja California provides a superb place to unravel the complexities because there is a lot of data and because it is longitudinally composed of two parts: an older western portion of weakly to moderately deformed, low-grade volcanic and epizonal plutonic rocks ranging in age from ~128–100 Ma; and a more easterly sector of deformed amphibolite grade rocks cut by compositionally zoned, mesozonal plutonic complexes of the La Posta suite, emplaced from 99–86 Ma. While plutons of the La Posta suite are generally considered to be the product of continued eastward subduction, they are enigmatic, because they and their wall rocks were rapidly exhumed from as deep as 23 km and eroded during, and just after, their emplacement, unlike plutons in magmatic arcs, which are generally emplaced in zones of subsidence. Here we resolve the enigma with a model where westward-dipping subduction led to arc magmatism of the western sector, the Santiago Peak–Alisitos composite arc, during the period ~128–100 Ma. Arc magmatism shut down when the arc collided with a west-facing Early Cretaceous passive margin at about 100 Ma. During the collision the buoyancy contrast between the continental crust of the eastern block and its attached oceanic lithosphere led to failure of the subducting slab. The break-off allowed subjacent asthenosphere to upwell, adiabatically melt, and rise into the upper plate to create the large zoned tonalite–granodiorite–granite complexes of the La Posta suite. While compositionally similar to arc plutons in many respects, the examples from the Southern California and Baja segments of the batholith have geochemistry that indicates they were derived from partial melting of asthenosphere at deeper levels in the mantle than typical arc magmas, and within the garnet stability field. This is consistent with asthenosphere upwelling through the torn lower-plate slab. We identify kindred rocks with similar geological relations in other Cordilleran batholiths of the Americas, such as the Sierra Nevada, which lead us to suggest that slab failure magmatism is common, both spatially and temporally.SOMMAIREDepuis la fin des années 1960, Warren Hamilton a proposé que les grands batholites de la Cordillère de l'ouest des Amériques sont les racines d’arcs volcaniques andéens issus de la subduction vers l'est de longue durée, et depuis la plupart des géologues ont emboîté le pas, bien qu’un nombre croissant d’indications montrent que de nombreux batholites de la Cordillère sont des entités composites complexes qui se sont développés lors d’intervalles intenses de contraction et d’exhumation, durant et entre les périodes de magmatisme. Le batholite Peninsular Ranges du Sud de la Californie et de Baja California est un excellent endroit permettant de démêler les choses parce qu'il y a beaucoup de données et parce qu'il est composé longitudinalement de deux parties: une partie occidentale plus ancienne, faiblement à modérément déformée, de roches volcaniques de faible métamorphisme et de roches plutoniques épizonales âgées d’environ 128 Ma à 100 Ma; et, d’un segment plus à l'est de roches amphiboliques déformées recoupées par des roches de composition zonée des complexes mésozonaux plutoniques de la suite de la Posta, mises en place entre 99 Ma et 86 Ma. Bien que les plutons de la suite La Posta sont généralement considérés comme le produit d’une subduction soutenue vers l’est, ils posent problème, parce qu'avec leurs roches encaissantes, ils ont été rapidement exhumés de profondeurs aussi grandes que 23 km, et érodées durant et juste après leur mise en place, contrairement aux plutons des arcs magmatiques, qui sont généralement mis en place dans les zones de subsidence. Dans le présent article, nous proposons une solution à ce problème, avec un modèle de subduction vers l'ouest qui conduit à un magmatisme d'arc du secteur ouest, l'arc composite de Santiago Peak-Alisitos, durant la période d’environ 128 Ma à 100 Ma. Le magmatisme d’arc s’est arrêté lorsque l'arc est entré en collision avec une marge passive à pendage ouest du début du Crétacé, il y a environ 100 Ma. Lors de la collision, le contraste de flottabilité entre la croûte continentale du bloc de est et la lithosphère océanique qui y est rattachée a conduit à l'avortement de la plaque plongeante. La cassure a entrainé la remontée de l’asthénosphère sous-jacente, sa fusion adiabatique, et sa remontée dans la plaque supérieure pour former les grands complexes zonés de tonalite-granodiorite-granite de La Posta. Bien que de composition similaire aux plutons d'arc à bien des égards, les exemples des segments de batholites de Californie du Sud et de Baja ont une géochimie qui indique qu'ils proviennent de la fusion partielle de l’asthénosphère à des niveaux plus profonds dans le manteau que les magmas d'arc typiques, à l’intérieur du domaine de stabilité du grenat. Ce qui correspond à une remontée d’asthénosphère à travers une dalle de plaque inférieure cassée. Nous connaissons des roches semblables avec les relations géologiques similaires dans d'autres batholites de la Cordillère des Amériques, tel celles de la Sierra Nevada, ce qui nous amène à penser que le magmatisme de cassure de plaque est commun, tant spatialement et temporellement.

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Forearc Basin Stratigraphy and Interactions With Accretionary Wedge Growth According to the Critical Taper Concept

Noda

2018

Tectonics

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Forearc basins are important constituents of sediment traps along subduction zones; the basin stratigraphy records various events that the basin experienced. Although the linkage between basin formation and accretionary wedge growth suggests that mass balance exerts a key control on their evolution, the interaction processes between basin and basement remain poorly understood. This study performed 2‐D numerical simulations in which basin stratigraphy was controlled by changes in sediment fluxes with accretionary wedge growth according to the critical taper concept. The resultant stratigraphy depended on the degree of filling (i.e., whether the basin was underfilled or overfilled) and the volume balance between the sediment flux supplied to the basin from the hinterland and the accommodation space in the basin. The trenchward progradation of deposition with onlapping contacts on the trenchside basin floor occurred during the underfilled phase, which formed a wedge‐shaped sedimentary unit. In contrast, the landward migration of the depocenter, with the tilting of strata, was characteristic for the overfilled phase. Condensed sections marked stratigraphic boundaries, indicating when sediment supply or accommodation space was limited. The accommodation‐limited intervals could have formed during the end of wedge uplift or when the taper angle decreased and possibly associated with the development of submarine canyons as conduits for bypassing sediments from the hinterland. Variations in sediment fluxes and their balance exerted a strong influence on the stratigraphic patterns in forearc basins. Assessing basin stratigraphy could be a key to evaluating how subduction zones evolve through their interactions with changing surface processes.

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Continental growth at convergent margins facing large ocean basins: a case study from Mesozoic convergent-margin basins of Baja California, Mexico

Cited by 95 publications

References 52 publications

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Untitled

Arc and Slab-Failure Magmatism in Cordilleran Batholiths II – The Cretaceous Peninsular Ranges Batholith of Southern and Baja California

Forearc Basin Stratigraphy and Interactions With Accretionary Wedge Growth According to the Critical Taper Concept

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