English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

A Late Jurassic seafloor remnant of the Rocas Verdes basin in southern Chile, the Sarmiento Complex (ca. 52°S), bears lithological  layers  with  bimodal ,meta-igneous  rocks  appropriate  for  a  comprehensive ,investigation  of  magma genesis in part of a lateral lithological transition from continental rifting to initial seafloor spreading. Metamorphosed,mafic rocks collected from different layers in the ophiolite pseudostratigraphy and a plagiogranite have positive εNd150values (+ 1 and +2). Granophyres, which are crosscut by ophiolitic mafic dikes, have negative εNd150values (-5). Dacitic dikes within thick successions,of pillow basalt have the least negative εNd150 values,(-3 and -4). Although mafic and felsic igneous rocks show contrasting isotopic signatures, thermochemical modeling (EC-AFC) suggests they can share a common,origin. Models consider an arbitrary composition,of the crustal assimilant (mostly metapelite with an average εNd150value of -7) and evaluate the feasibility for generation of silicic melts through the interaction of mafic magmas,and metasedimentary,rocks. A quantitative evaluation of basaltic magma,contaminated,by crustal wall rocks requires a Ma/ Mc (mass of anatectic melt/ mass of cumulates) ratio of 0.04. Analyses using dikes of dacite (with Ma/Mc ratios ranging between,0.28-0.35)  and  granophyres ,(with  Ma/Mc  ratios  of  0.63-0.89)  require  the  silicic  magmas ,to  contain ,higher proportions of anatectic melts derived from metamorphic,rocks. Isotopic differences among,granophyres,and dacites could be  controlled  by  eruption  dynamics,  regional  stress  field  and/or  differences  in  thermal  regimes  in  magma chambers. Bimodal magmatism,in the earliest tectonic evolution of the Rocas Verdes basin could reflect regimes of slow extension of  the  continental  crust  along  the  Jurassic  southwestern ,margin  of  Gondwana. Key words: Rocas Verdes basin, Sarmiento Complex, Bimodal magmatism, Petrogenesis, Patagonia, Chile. RESUMEN Interacciones corteza-manto,y generación de fundidos silíceos: perspectivas,desde,el Complejo

Crust-mantle interactions and generation of silicic melts: insights from the Sarmiento Complex, southern Patagonian Andes