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Secular Geochemistry of Central Puerto Rican Island Arc Lavas: Constraints on Mesozoic Tectonism in the Eastern Greater Antilles 总被引:2,自引:0,他引:2
JOLLY WAYNE T.; LIDIAK EDWARD G.; DICKIN ALAN P.; WU TSAI-WAY 《Journal of Petrology》2001,42(12):2197-2214
Island arc volcanism in the Greater Antilles persisted for >70m.y. from Middle Cretaceous to Late Eocene time. During theinitial 50 m.y., lavas in central Puerto Rico shifted from predominantlyisland arc tholeiites (volcanic phase I, Aptian to Early Albian,120105 Ma), to calc-alkaline basalts (phase II, LateAlbian, 10597 Ma), and finally to high-K, incompatible-element-enrichedbasalts (phases III and IV, CenomanianMaastrichtian,9770 Ma). Following an island-wide eruptive hiatus, geochemicaltrends were reversed in the Eocene with renewed eruption ofcalc-alkaline basalts (phase V, 6045 Ma). Progressiveincreases in large-ion lithophile elements (LILE)/light rareearth elements (LREE), LILE/high field strength elements (HFSE),LREE/HFSE, and HFSE/heavy rare earth elements (HREE) characterizethe compositional evolution of the first four volcanic phases.The shift in trace element compositions is mirrored by increasingradiogenic content of the lavas. Pb 相似文献
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