Hoernle, Kaj , van den Bogaard, Paul, Werner, Reinhard, Lissinna, Britta, Hauff, Folkmar, Alvarado, Guillermo and Garbe-Schönberg, C.-Dieter (2002) The Missing History (16-71 Ma) of the Galápagos Hotspot: Implications for the Tectonic and Biological Evolution of the Americas. Geology, 30 . pp. 795-798. DOI 10.1130/0091-7613(2002)030<0795:MHMOTG>2.0.CO;2.

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Abstract

We present the results of volcanological, geochemical, and geochronological studies of
volcanic rocks from Malpelo Island on the Nazca plate (15.8–17.3 Ma) belonging to the
Gala´pagos hotspot tracks, and igneous complexes (20.8–71.3 Ma) along the Pacific margin
of Costa Rica and Panama. The igneous complexes consist of accreted portions of ocean
island and seamount volcanoes and aseismic ridges, representing the missing (primarily
subducted) history of the Gala´pagos hotspot. The age and geochemical data directly link
the Gala´pagos hotspot tracks on the Pacific Ocean floor to the Caribbean large igneous
province (ca. 72–95 Ma), confirming a Pacific origin for the Caribbean oceanic plateau
from the Gala´pagos hotspot. We propose that emplacement of this oceanic plateau between
the Americas and interaction of the Gala´pagos hotspot tracks with the Central American
Arc played a fundamental role in the formation of land bridges between the Americas in
Late Cretaceous–Paleocene and Pliocene-Holocene time. The land bridges allowed the
exchange of terrestrial faunas (e.g., dinosaurs, mastodons, saber-tooth cats, and ground
sloths) between the Americas and served as barriers for the exchange of marine organisms
between the central Pacific Ocean and the Caribbean Sea and the central Atlantic Ocean.

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