Late Jurassic to Eocene geochemical evolution of volcanic rocks in Puerto Rico

Journal Article · Fri Mar 01 00:00:00 EST 1991 · Geophysical Research Letters (American Geophysical Union); (United States)

DOI:https://doi.org/10.1029/91GL00398· OSTI ID:5559012

Schellekens, J H ^[1]

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1. Univ. of Puerto Rico, Mayaguez (Puerto Rico)

The Late Jurassic to Eocene deformed volcanic, volcaniclastic and sedimentary rocks of Puerto Rico are divided into three igneous provinces, the southwestern, central, and northeastern igneous province. Based on the stratigraphic position approximate ages could be assigned to the flow rocks in these provinces. Ba/Nb and La/Sm diagrams are presented to illustrate the origin and evolution of the flow rocks. The oldest rock in the southwestern province may include MORB. Early Cretaceous volcanic rocks in the central and northeastern province have low Ba/nb and La/Sm, that are interpreted as an early island arc stage, with none or only minor contribution of slab-derived material. The Late Cretaceous to Eocene volcanic rocks have a wide range of values for the Ba/Nb and La/Sm that are interpreted as the result of admixture of a variable amount of slab-derived material. The Maricao Basalt (Maastrichtian to Eocene) in the southeastern igneous province has the geochemical signature of magmas formed in an extensional setting.

• OSTI ID: 5559012
• Journal Information: Geophysical Research Letters (American Geophysical Union); (United States), Vol. 18:3; ISSN 0094-8276
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
PUERTO RICO
VOLCANIC REGIONS
GEOCHEMISTRY
VOLCANIC ROCKS
AGE ESTIMATION
BARIUM
BASALT
CRETACEOUS PERIOD
DEFORMATION
EOCENE EPOCH
IGNEOUS ROCKS
JURASSIC PERIOD
LANTHANUM
NIOBIUM
ORIGIN
PLUTONIC ROCKS
QUANTITY RATIO
SAMARIUM
STRATIGRAPHY
ALKALINE EARTH METALS
CENOZOIC ERA
CHEMISTRY
DEVELOPED COUNTRIES
ELEMENTS
GEOLOGIC AGES
GEOLOGY
GREATER ANTILLES
ISLANDS
LATIN AMERICA
MESOZOIC ERA
METALS
NORTH AMERICA
RARE EARTHS
ROCKS
TERTIARY PERIOD
TRANSITION ELEMENTS
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