|
|||||
|
|
Secular Geochemistry of Central Puerto Rican Island Arc Lavas: Constraints on Mesozoic Tectonism in the Eastern Greater Antilles |
|
| Authors: | JOLLY WAYNE T; LIDIAK EDWARD G; DICKIN ALAN P; WU TSAI-WAY |
| Institution: | 1DEPARTMENT OF EARTH SCIENCES, BROCK UNIVERSITY, ST. CATHARINES, ONT., CANADA L2S 3A1 2DEPARTMENT OF GEOLOGY AND PLANETARY SCIENCES, UNIVERSITY OF PITTSBURGH, PITTSBURGH, PA 15260, USA 3DEPARTMENT OF GEOLOGY, McMASTER UNIVERSITY, HAMILTON, ONT., CANADA L8S 4M1 4DEPARTMENT OF GEOLOGY, UNIVERSITY OF WESTERN ONTARIO, LONDON, ONT., CANADA N6A 5B7 |
| Abstract: | 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,120–105 Ma), to calc-alkaline basalts (phase II, LateAlbian, 105–97 Ma), and finally to high-K, incompatible-element-enrichedbasalts (phases III and IV, Cenomanian–Maastrichtian,97–70 Ma). Following an island-wide eruptive hiatus, geochemicaltrends were reversed in the Eocene with renewed eruption ofcalc-alkaline basalts (phase V, 60–45 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 |
| Keywords: | |
| 本文献已被 Oxford 等数据库收录！ | |