Matches in SemOpenAlex for { <https://semopenalex.org/work/W2475163617> ?p ?o ?g. }
- W2475163617 endingPage "191" @default.
- W2475163617 startingPage "169" @default.
- W2475163617 abstract "The tectonic and geodynamic setting of the southern Central Andean convergent margin changed significantly between the Late Cretaceous and the Late Miocene, influencing magmatic activity and its geochemical composition. Here we investigate how these changes, which include changing slab-dip angle and convergence angles and rates, have influenced the contamination of the arc magmas with crustal material. Whole rock geochemical data for a suite of Late Cretaceous to Late Miocene arc rocks from the Pampean flat-slab segment (29–31 °S) of the southern Central Andes is presented alongside petrographic observations and high resolution age dating. In-situ U–Pb dating of magmatic zircon, combined with Ar–Ar dating of plagioclase, has led to an improved regional stratigraphy and provides an accurate temporal constraint for the geochemical data. A generally higher content of incompatible trace elements (e.g. Nb/Zr ratios from 0.019 to 0.083 and Nb/Yb from 1.5 to 16.4) is observed between the Late Cretaceous (~ 72 Ma), when the southern Central Andean margin is suggested to have been in extension, and the Miocene when the thickness of the continental crust increased and the angle of the subducting Nazca plate shallowed. Trace and rare earth element compositions obtained for the Late Cretaceous to Late Eocene arc magmatic rocks from the Principal Cordillera of Chile, combined with a lack of zircon inheritance, suggest limited assimilation of the overlying continental crust by arc magmas derived from the mantle wedge. A general increase in incompatible, fluid-mobile/immobile (e.g., Ba/Nb) and fluid-immobile/immobile (e.g., Nb/Zr) trace element ratios is attributed to the influence of the subducting slab on the melt source region and/or the influx of asthenospheric mantle. The Late Oligocene (~ 26 Ma) to Early Miocene (~ 17 Ma), and Late Miocene (~ 6 Ma) arc magmatic rocks present in the Frontal Cordillera show evidence for the bulk assimilation of the Permian–Triassic (P–T) basement, both on the basis of their trace and rare earth element compositions and the presence of P–T inherited zircon cores. Crustal reworking is also identified in the Argentinean Precordillera; Late Miocene (12–9 Ma) arc magmatic rocks display distinct trace element signatures (specifically low Th, U and REE concentrations) and contain inherited zircon cores with Proterozoic and P–T ages, suggesting the assimilation of both the P–T basement and a Grenville-aged basement. We conclude that changing geodynamics play an important role in determining the geochemical evolution of magmatic rocks at convergent margins and should be given due consideration when evaluating the petrogenesis of arc magmas." @default.
- W2475163617 created "2016-07-22" @default.
- W2475163617 creator A5006865106 @default.
- W2475163617 creator A5007086120 @default.
- W2475163617 creator A5010615331 @default.
- W2475163617 creator A5022666378 @default.
- W2475163617 creator A5037488129 @default.
- W2475163617 creator A5088234064 @default.
- W2475163617 creator A5089457940 @default.
- W2475163617 date "2016-10-01" @default.
- W2475163617 modified "2023-10-14" @default.
- W2475163617 title "The role of changing geodynamics in the progressive contamination of Late Cretaceous to Late Miocene arc magmas in the southern Central Andes" @default.
- W2475163617 cites W1495115150 @default.
- W2475163617 cites W1520044904 @default.
- W2475163617 cites W1975759160 @default.
- W2475163617 cites W1979705656 @default.
- W2475163617 cites W1980657658 @default.
- W2475163617 cites W1981780561 @default.
- W2475163617 cites W1991431025 @default.
- W2475163617 cites W1995071771 @default.
- W2475163617 cites W1996176618 @default.
- W2475163617 cites W1997142214 @default.
- W2475163617 cites W1998707404 @default.
- W2475163617 cites W2000896842 @default.
- W2475163617 cites W2002519975 @default.
- W2475163617 cites W2007557785 @default.
- W2475163617 cites W2008456126 @default.
- W2475163617 cites W2009776043 @default.
- W2475163617 cites W2010602854 @default.
- W2475163617 cites W2014587695 @default.
- W2475163617 cites W2021987309 @default.
- W2475163617 cites W2022017333 @default.
- W2475163617 cites W2023320566 @default.
- W2475163617 cites W2029869558 @default.
- W2475163617 cites W2032535771 @default.
- W2475163617 cites W2032992631 @default.
- W2475163617 cites W2035415378 @default.
- W2475163617 cites W2035932728 @default.
- W2475163617 cites W2038775297 @default.
- W2475163617 cites W2042347378 @default.
- W2475163617 cites W2045324661 @default.
- W2475163617 cites W2045582693 @default.
- W2475163617 cites W2045764404 @default.
- W2475163617 cites W2046461727 @default.
- W2475163617 cites W2049451277 @default.
- W2475163617 cites W2057550910 @default.
- W2475163617 cites W2057928940 @default.
- W2475163617 cites W2057987054 @default.
- W2475163617 cites W2058441944 @default.
- W2475163617 cites W2060146764 @default.
- W2475163617 cites W2060665592 @default.
- W2475163617 cites W2064167853 @default.
- W2475163617 cites W2067257157 @default.
- W2475163617 cites W2067268804 @default.
- W2475163617 cites W2067480049 @default.
- W2475163617 cites W2069193736 @default.
- W2475163617 cites W2070849515 @default.
- W2475163617 cites W2076853563 @default.
- W2475163617 cites W2077942848 @default.
- W2475163617 cites W2079879778 @default.
- W2475163617 cites W2081003843 @default.
- W2475163617 cites W2086136946 @default.
- W2475163617 cites W2086889116 @default.
- W2475163617 cites W2087662765 @default.
- W2475163617 cites W2089058535 @default.
- W2475163617 cites W2091124264 @default.
- W2475163617 cites W2091539092 @default.
- W2475163617 cites W2092222346 @default.
- W2475163617 cites W2099128650 @default.
- W2475163617 cites W2107544091 @default.
- W2475163617 cites W2108460919 @default.
- W2475163617 cites W2108597026 @default.
- W2475163617 cites W2110183995 @default.
- W2475163617 cites W2111230711 @default.
- W2475163617 cites W2112619531 @default.
- W2475163617 cites W2114402972 @default.
- W2475163617 cites W2115393563 @default.
- W2475163617 cites W2118730176 @default.
- W2475163617 cites W2120557403 @default.
- W2475163617 cites W2120824396 @default.
- W2475163617 cites W2121188225 @default.
- W2475163617 cites W2122790267 @default.
- W2475163617 cites W2127172635 @default.
- W2475163617 cites W2129147605 @default.
- W2475163617 cites W2138522501 @default.
- W2475163617 cites W2139498789 @default.
- W2475163617 cites W2145229491 @default.
- W2475163617 cites W2145898590 @default.
- W2475163617 cites W2146941374 @default.
- W2475163617 cites W2148825499 @default.
- W2475163617 cites W2152642790 @default.
- W2475163617 cites W2155778073 @default.
- W2475163617 cites W2161188118 @default.
- W2475163617 cites W2164911500 @default.
- W2475163617 cites W2270932692 @default.
- W2475163617 cites W2321208578 @default.
- W2475163617 cites W2346751741 @default.
- W2475163617 cites W4211136963 @default.