No latest activity reported for San Luis, Isla.

Below is a summary of eruption dates and Volcanic Explosivity Indices (VEI).

The following references are the sources used for data regarding this volcano. References are linked directly to our volcano data file. Discussion of another volcano or eruption (sometimes far from the one that is the subject of the manuscript) may produce a citation that is not at all apparent from the title. Additional discussion of data sources can be found under Volcano Data Criteria.

Gastil R G, Phillips R P, Allison E C, 1975. Reconnaissance geology of the State of Baja California. {Geol Soc Amer Mem}, 140: 1-170

Medina F, Suarez F, Espindola J M, 1989. Historic and Holocene volcanic centers in NW Mexico. {Bull Volc Eruptions}, 26: 91-93

Paz Moreno F A, Demant A, 1999. The Recent Isla San Luis volcanic centre: petrology of a rift-related volcanic suite in the northern Gulf of California, Mexico. {J Volc Geotherm Res}, 93: 31-52

Isla San Luis is the largest of the seven Encantada islands at the NW end of the Guaymas lineament in the northern part of the Gulf of California. The roughly 180-m-high island (also known as La Encantada Mayor, or Salvatierra) is located 3 km off the eastern shore of Baja California north of Punta Bufeo. The small 4.5 sq km island has an irregular shoreline with a narrow peninsula forming its SW tip. Initial basaltic-andesite and andesitic submarine surtseyan eruptions producing palagonite tuffs were followed by the effusion of subaerial dacitic lava flows and the formation of dacitic tuff rings. The latest eruptions formed two rhyolitic obsidian domes, the younger in a tuff cone at the center of the island and at the older at the NW tip of the island. Although the age of the domes is not known precisely, Medina et al. (1989) suggested that they could be less than a century old.