Matches in SemOpenAlex for { <https://semopenalex.org/work/W2001552813> ?p ?o ?g. }
- W2001552813 endingPage "53" @default.
- W2001552813 startingPage "27" @default.
- W2001552813 abstract "The Vilama caldera is one of the very large-volume volcanic structures that formed during the ignimbrite flare-up that lasted from 10 Ma to 4 Ma on the central Andean plateau. Formerly, the Vilama structure was interpreted as a 65 × 40 km wide caldera with a two stage evolution. New field correlations, petrographical, geochemical and geochronological data lead to a substantially larger reinterpreted Vilama ignimbrite, whose outcrops cover more than 4000 km2. New and existing K/Ar and Ar/Ar dating shows that the dacitic Vilama ignimbrite erupted from the Vilama caldera at 8.4–8.5 Ma. The ignimbrite can be divided into extracaldera outflow and intracaldera deposits. The outflow has a mean thickness of ∼ 40 m and is separated into a restricted valley-ponded lower cooling unit, and a laterally extensive low aspect ratio upper cooling unit. The Vilama caldera, which is roughly rectangular (35–40 km × 15–18 km) in shape and has central coordinates of 22°24′ S and 66°57′ W, is considered to have formed in a single-stage collapse event. As the topographic rim is only seen on the western side, the extent of collapse and geometry of the caldera are incompletely known and inferred from indirect data. Possible collapse geometries include a slightly asymmetric single-block subsidence and non-chaotic multiple-block collapse. Estimated erupted volumes range from ∼ 1800 to 1200 km3, or 1400 to 1000 km3 in dense rock equivalents. The properties of the Vilama ignimbrite which include a crystal-rich and pumice-poor nature, a high degree of welding and induration and a prodigious volume, suggest that an external drive, rather than volatile overpressures, controlled and maintained the eruption. The best candidate is caldera subsidence triggered by the instability of a magma chamber roof above a batholith-scale magma body. Transtensive/distensive tectonic stresses resulted in the northwest elongation of the magma chamber and/or influenced the roughly rectangular/subelliptical shape of the subsided block. As most of the Vilama ignimbrite is within the caldera, subsidence must have started early in the eruptive history. Immediately before, or concomitantly with the onset of subsidence, the lower extracaldera unit was deposited from flows that formed during collapse of well-developed plumes with efficient convective phases. Once caldera collapse was completely established, the eruption dynamic changed dramatically, and the extracaldera and intracaldera facies erupted. During this phase, unstable and low plumes (boiling-over collapse fountains) preferentially collapsed towards the interior of the subsiding structure, causing the ignimbrite volume to be concentrated in the caldera. After much less than 1 Ma, resurgence, which might be linked to magma chamber recharge, domed the intracaldera facies and caused post-collapse volcanism to be channeled through subsidence and/or resurgence-related faults." @default.
- W2001552813 created "2016-06-24" @default.
- W2001552813 creator A5014448059 @default.
- W2001552813 creator A5019348192 @default.
- W2001552813 creator A5028320377 @default.
- W2001552813 creator A5074101355 @default.
- W2001552813 creator A5080166629 @default.
- W2001552813 date "2007-07-01" @default.
- W2001552813 modified "2023-10-09" @default.
- W2001552813 title "Geology of the Vilama caldera: A new interpretation of a large-scale explosive event in the Central Andean plateau during the Upper Miocene" @default.
- W2001552813 cites W1969267788 @default.
- W2001552813 cites W1975784752 @default.
- W2001552813 cites W1977796178 @default.
- W2001552813 cites W1978696207 @default.
- W2001552813 cites W1980251125 @default.
- W2001552813 cites W1999757037 @default.
- W2001552813 cites W2001548637 @default.
- W2001552813 cites W2003247029 @default.
- W2001552813 cites W2004492737 @default.
- W2001552813 cites W2008813603 @default.
- W2001552813 cites W2010153364 @default.
- W2001552813 cites W2011971603 @default.
- W2001552813 cites W2014223712 @default.
- W2001552813 cites W2016349619 @default.
- W2001552813 cites W2023617748 @default.
- W2001552813 cites W2032191042 @default.
- W2001552813 cites W2032304039 @default.
- W2001552813 cites W2033927110 @default.
- W2001552813 cites W2037611419 @default.
- W2001552813 cites W2039731389 @default.
- W2001552813 cites W2040712836 @default.
- W2001552813 cites W2043747343 @default.
- W2001552813 cites W2065815288 @default.
- W2001552813 cites W2073861340 @default.
- W2001552813 cites W2079537944 @default.
- W2001552813 cites W2082967880 @default.
- W2001552813 cites W2090312790 @default.
- W2001552813 cites W2103106983 @default.
- W2001552813 cites W2104144529 @default.
- W2001552813 cites W2110183995 @default.
- W2001552813 cites W2113822625 @default.
- W2001552813 cites W2124448994 @default.
- W2001552813 cites W2140798780 @default.
- W2001552813 cites W2141301683 @default.
- W2001552813 cites W2145158179 @default.
- W2001552813 cites W2152364283 @default.
- W2001552813 cites W2167893737 @default.
- W2001552813 cites W2263602010 @default.
- W2001552813 doi "https://doi.org/10.1016/j.jvolgeores.2007.04.002" @default.
- W2001552813 hasPublicationYear "2007" @default.
- W2001552813 type Work @default.
- W2001552813 sameAs 2001552813 @default.
- W2001552813 citedByCount "51" @default.
- W2001552813 countsByYear W20015528132012 @default.
- W2001552813 countsByYear W20015528132013 @default.
- W2001552813 countsByYear W20015528132014 @default.
- W2001552813 countsByYear W20015528132015 @default.
- W2001552813 countsByYear W20015528132016 @default.
- W2001552813 countsByYear W20015528132017 @default.
- W2001552813 countsByYear W20015528132018 @default.
- W2001552813 countsByYear W20015528132019 @default.
- W2001552813 countsByYear W20015528132020 @default.
- W2001552813 countsByYear W20015528132021 @default.
- W2001552813 countsByYear W20015528132022 @default.
- W2001552813 countsByYear W20015528132023 @default.
- W2001552813 crossrefType "journal-article" @default.
- W2001552813 hasAuthorship W2001552813A5014448059 @default.
- W2001552813 hasAuthorship W2001552813A5019348192 @default.
- W2001552813 hasAuthorship W2001552813A5028320377 @default.
- W2001552813 hasAuthorship W2001552813A5074101355 @default.
- W2001552813 hasAuthorship W2001552813A5080166629 @default.
- W2001552813 hasConcept C114793014 @default.
- W2001552813 hasConcept C120806208 @default.
- W2001552813 hasConcept C127313418 @default.
- W2001552813 hasConcept C134306372 @default.
- W2001552813 hasConcept C146348940 @default.
- W2001552813 hasConcept C165205528 @default.
- W2001552813 hasConcept C169212394 @default.
- W2001552813 hasConcept C17409809 @default.
- W2001552813 hasConcept C2780030769 @default.
- W2001552813 hasConcept C33923547 @default.
- W2001552813 hasConcept C49708893 @default.
- W2001552813 hasConcept C95869378 @default.
- W2001552813 hasConceptScore W2001552813C114793014 @default.
- W2001552813 hasConceptScore W2001552813C120806208 @default.
- W2001552813 hasConceptScore W2001552813C127313418 @default.
- W2001552813 hasConceptScore W2001552813C134306372 @default.
- W2001552813 hasConceptScore W2001552813C146348940 @default.
- W2001552813 hasConceptScore W2001552813C165205528 @default.
- W2001552813 hasConceptScore W2001552813C169212394 @default.
- W2001552813 hasConceptScore W2001552813C17409809 @default.
- W2001552813 hasConceptScore W2001552813C2780030769 @default.
- W2001552813 hasConceptScore W2001552813C33923547 @default.
- W2001552813 hasConceptScore W2001552813C49708893 @default.
- W2001552813 hasConceptScore W2001552813C95869378 @default.
- W2001552813 hasIssue "1-2" @default.
- W2001552813 hasLocation W20015528131 @default.
- W2001552813 hasOpenAccess W2001552813 @default.