Extensional Lower Cretaceous volcanism in the Coastal Range (29°20′–30°S), Chile: geochemistry and petrogenesis

Morata, Diego; Aguirre, Luis

doi:10.1016/j.jsames.2003.06.001

Cited by 40 publications

(15 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Most of the previous tectonic interpretations assumed that the intra-arc basin stage was related either to a low-spreading rate of 5 cm/year in the Pacific ridge at that time (Ä berg et al 1984;Morata and Aguirre 2003), or to a low relative convergence velocity in the subduction zone (Ramos 1985). However, later studies suggested that the factor controlling the extensional setting was mainly related to the important eastward absolute motion of South America relative to the Pacific hotspot frame (Somoza 1995;Somoza and Zaffarana 2008), which resulted in a trench roll-back (Vt < 0) and generalized extension (Ramos 1999;Mpodozis and Ramos 2008).…”

Section: Central Chile Basin (288-358s Lat)mentioning

confidence: 99%

The tectonic regime along the Andes: Present‐day and Mesozoic regimes

Ramos¹

2009

Geological Journal

227

139

View full text Add to dashboard Cite

The analyses of the main parameters controlling the present Chile-type and Marianas-type tectonic settings developed along the eastern Pacific region show four different tectonic regimes: (1) a nearly neutral regime in the Oregon subduction zone; (2) major extensional regimes as the Nicaragua subduction zone developed in continental crust; (3) a Marianas setting in the Sandwich subduction zone with ocean floored back-arc basin with a unique west-dipping subduction zone and (4) the classic and dominant Chile-type under compression. The magmatic, structural and sedimentary behaviours of these four settings are discussed to understand the past tectonic regimes in the Mesozoic Andes based on their present geological and tectonic characteristics. The evaluation of the different parameters that governed the past and present tectonic regimes indicates that absolute motion of the upper plate relative to the hotspot frame and the consequent trench roll-back velocity are the first order parameters that control the deformation. Locally, the influences of the trench fill, linked to the dominant climate in the forearc, and the age of the subducted oceanic crust, have secondary roles. Ridge collisions of seismic and seismic oceanic ridges as well as fracture zone collisions have also a local outcome, and may produce an increase in coupling that reinforces compressional deformation. Local strain variations in the past and present Andes are not related with changes in the relative convergence rate, which is less important than the absolute motion relative to the Pacific hotspot frame, or changes in the thermal state of the upper plate. Changes in the slab dip, mainly those linked to steepening subduction zones, produce significant variations in the thermal state, that are important to generate extreme deformation in the foreland.

show abstract

Section: Central Chile Basin (288-358s Lat)mentioning

confidence: 99%

The tectonic regime along the Andes: Present‐day and Mesozoic regimes

Ramos¹

2009

Geological Journal

227

139

View full text Add to dashboard Cite

show abstract

“…The andesitic and rare felsic rocks from these formations lack orthopyroxene (Vergara et al, 1995;Morata and Aguirre, 2003). Intrusive rocks in the Coastal Cordillera comprise gabbro-diorite, tonalite, and granodiorite, which are mainly composed of calcic plagioclase, K-feldspar, and quartz.…”

Section: Relationships and Timing Between The Coastal Deposits And Mamentioning

confidence: 99%

Pliocene lahar deposits in the Coastal Cordillera of central Chile: Implications for uplift, avalanche deposits, and porphyry copper systems in the Main Andean Cordillera

Encinas

Maksaev

Pinto

et al. 2006

Journal of South American Earth Sciences

View full text Add to dashboard Cite

“…In this locality the upper part of the Pabell on Formation appears to be missing by erosion, this interpretation is supported by the absence of porphyry andesite (see above) or any volcanic episode recognized regionally, e.g. Quebrada Carrizalillo, Quebrada El Molle and Llano de Arqueros, dated as late Aptian, i.e.À115 Ma (Morata et al, 2001;Morata and Aguirre, 2003). The foregoing suggests that the Douvilleliabearing beds are early Aptian in age.…”

Section: Biostratigraphy Of Rudist Bearing Formationsmentioning

confidence: 99%