Popis: |
The Cretaceous period was marked by the most voluminous episodes of oceanic plateau volcanism in the Phanerozoic Eon. Primarily affecting the Pacific, mantle plumes generated oceanic plateaus during three main phases (ca. 145–140 Ma, ca. 122–115 Ma, and ca. 100–90 Ma). Central America is one of the very few circum-Pacific margins where remnants of these Cretaceous plateaus were accreted. The study of their onland exposures provides a highly valuable insight into the complexity and diversity of oceanic plateau histories, from their eruption to their accretion. Exposed in northern Costa Rica, the plateau remnants of the Nicoya Peninsula originated from a Jurassic oceanic crust over-thickened by Early and Late Cretaceous hotspots. These sheared-off pieces of the Farallon Plate testify to the early tectonic interaction of the Caribbean Large Igneous Province (CLIP, ca. 94–89 Ma) with North America, initiated |