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The Global Volcanism Program has no activity reports for Isla Tortuga.
The Global Volcanism Program has no Weekly Reports available for Isla Tortuga.
The Global Volcanism Program has no Bulletin Reports available for Isla Tortuga.
A youthful shield volcano forms Isla Tortuga, which lies in the Gulf of California 40 km off the Baja coast. A circular, 1-km-wide caldera, west of the center of the oval, 4-km-long island, truncates the small shield volcano, which reaches only about 210 m above sea level. Circumferential faults cut the rim of the >100-m-deep caldera, which is floored by a solidified lava lake and contains youthful-looking spatter cones. The shield volcano was constructed during two north-migrating periods of activity that began with submarine eruptions and included formation of a circular tuff-ring complex enclosing the caldera. The sides of a small volcanic horst in the center of the caldera display lava flows overlying a 2-m-thick halite bed, formed when sea water filled the caldera, creating an evaporite basin. Recent lava flows cover most of the flanks of the volcano, and fumarolic activity has continued into historical time.
The Global Volcanism Program is not aware of any Holocene eruptions from Isla Tortuga. If this volcano has had large eruptions (VEI >= 4) prior to 10,000 years ago, information might be found on the Isla Tortuga page in the LaMEVE (Large Magnitude Explosive Volcanic Eruptions) database, a part of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).
The Global Volcanism Program has no synonyms or subfeatures listed for Isla Tortuga.
|Isla Tortuga is 4-km-wide volcanic island located in the Gulf of California, 40 km off the coast of Baja California. The flat-topped summit of the 210-m-high shield volcano contains a 1-km-wide caldera. Recent lava flows cover much of the surface of the volcano. This 1989 view is from the west. No historical eruptions are known from Tortuga, although fumarolic activity continues.
Photo by Marjorie Summers, 1989 (Smithsonian Institution).
The following references have all been used during the compilation of data for this volcano, it is not a comprehensive bibliography. 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.
Batiza R, 1978. Geology, petrology, and geochemistry of Isla Tortuga, a recently formed tholeiitic island in the Gulf of California. Geol Soc Amer Bull, 89: 1309-1324.
Batiza R, Futa K, Hedge C E, 1979. Trace element and strontium isotope characteristics of volcanic rocks from Isla Tortuga: a young seamount in the Gulf of California. Earth Planet Sci Lett, 43: 269-278.
Beal C H, 1948. Reconnaissance of the geology and oil possibilities of Baja California, Mexico. Geol Soc Amer Mem, 31: 1-138.