Petit-spot lava fields off the central Chile trench induced by plate flexure

• DOI: 10.2343/geochemj.2.0227
• Publication Date: 2013-11-22T23:14:36Z
• Authors: NAOTO HIRANO; SHIKI MACHIDA; NATSUE ABE; TOMOAKI MORISHITA; AKIHIRO TAMURA; SHOJI ARAI
• Keywords: Hotspot (geology); Alkali basalt; Pacific Plate

In 2009, petit-spot submarine volcanoes were discovered off the oceanward slope of central Chile trench, offshore from Valparaiso, Chile, at around 33°S. Ar-Ar dating mugearite and alkali-basalt yields ages 10.11 ± 0.22 Ma 6.69 0.88 Ma, respectively. Back-calculations plate motion along present absolute movement direction Nazca Plate, conducted using age data, indicate that eruption occurred above a zone flexure. The back-calculation results suggest was erupted flexural arch prior to arrival active site Juan Fernández hotspot. contrast, on flexure interaction between moat an outer-rise area, where source material probably influenced by geochemistry lavas supports this interpretation because concentration ratios various rare earth other trace elements in are different those hotspot lavas. Consequently, melts could reflect composition materials below plates sites