Geological Summary

The low shield volcano of Floreana Island, also known as Charles Island or Santa María Island, is densely covered with cinder cones. A 5-km-wide caldera at the center of the island has an irregular floor. Several young lava flows were considered to have been as young as few thousand or even a few centuries old based on their youthful morphology (McBirney and Williams, 1969), but a surface exposure age of 26 ± 7 ka was obtained on the youngest flow (Kurz and Geist, 1999). An 1813 eruption attributed to Floreana in the Catalog of Active Volcanoes of the World is considered to have actually occurred at Sierra Negra volcano on Isabela Island (Simkin 1980, pers. comm.). The most conspicuous of the cinder cones on the island is Cerro de Pajas, which rises 335 m above its surroundings. It fed a massive pahoehoe lava flow, perhaps the youngest on Floreana, that reached the SW coast over a broad 6.5 km area.

This volcano is located within the Archipiélago de Colón (Galápagos), a UNESCO World Heritage property.

References

The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography.

IAVCEI, 1973-80. Post-Miocene Volcanoes of the World. IAVCEI Data Sheets, Rome: Internatl Assoc Volc Chemistry Earth's Interior.

Kurz M D, Geist D, 1999. Dynamics of the Galapagos hotspot from helium isotope geochemistry. Geochim Cosmochim Acta, 63: 4139-4156.

McBirney A R, Williams H, 1969. Geology and petrology of the Galapagos Islands. Geol Soc Amer Mem, 118: 1-197.

Richards A F, 1962. Archipelago de Colon, Isla San Felix and Islas Juan Fernandez. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI, 14: 1-50.

Simkin T, 1984. Geology of Galapagos Islands. In: Perry R (ed) Galapagos, Oxford: Pergamon, p 15-41.

Simkin T, 1980. (pers. comm.).

White W M, McBirney A R, Duncan R A, 1993. Petrology and geochemistry of the Galapagos Islands: Portrait of a pathological mantle plume. J. Geophys. Res, 98: 19,533-19,563.