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Isla San Luis

Photo of this volcano
  • Country
  • Volcanic Region
  • Landform | Volc Type
  • Last Known Eruption
  • 29.9728°N
  • 114.4082°W

  • 183 m
    600 ft

  • 341003
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

The Global Volcanism Program has no activity reports available for Isla San Luis.

The Global Volcanism Program has no Weekly Reports available for Isla San Luis.

The Global Volcanism Program has no Bulletin Reports available for Isla San Luis.

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Eruptive History

There is data available for 3 confirmed Holocene eruptive periods.

1141 BCE ± 203 years Confirmed Eruption  

Episode 1 | Eruption Central rhyolite domes
1141 BCE ± 203 years - Unknown Evidence from Isotopic: 14C (uncalibrated)
 Seven marine mollusk shells were analyzed by Hausback et al. (2003) using 14C acceleration methods to date beach deposits at three stratigraphic levels interbedded with volcanic layers. Three shells were dated in beach sands directly below the youngest of the pyroclastic deposits on the island: coarse, rhyolitic breadcrust-bomb-containing tephras associated with the early eruptive stages of the growth of the central rhyolite domes; these yield a maximum age of 2,888 to 3,289 BP for the latest rhyolite eruptions. Hausback et al. (2003) also attempted to use obsidian hydration analysis to date this material, measuring hydration rinds of 3.6 and 3.7 microns thickness two separate bombs (averages of 5 measurements each); the hydration rate for this obsidian has not been established, but a typical hydration rate (82.74 microns ^2.06) yields an age of 1,225 years for this tephra (725 CE).

List of 1 Events for Episode 1 at Central rhyolite domes

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Tephra

1212 BCE ± 127 years Confirmed Eruption  

Episode 1 | Eruption NW beach cliffs
1212 BCE ± 127 years - Unknown Evidence from Isotopic: 14C (uncalibrated)
 Seven marine mollusk shells were analyzed by Hausback et al. (2003) using 14C acceleration methods to date beach deposits at three stratigraphic levels interbedded with volcanic layers. Three mollusks were dated in beach deposits below the intermediate lavas exposed along the NW beach cliffs; these give a maximum age of 3,036 to 3,289 BP.

List of 1 Events for Episode 1 at NW beach cliffs

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Lava flow

2647 BCE ± 128 years Confirmed Eruption  

Episode 1 | Eruption
2647 BCE ± 128 years - Unknown Evidence from Isotopic: 14C (uncalibrated)
 Seven marine mollusk shells were analyzed by Hausback et al. (2003) using 14C acceleration methods to date beach deposits at three stratigraphic levels interbedded with volcanic layers. One shell was dated at 4,469-4,725 BP from the oldest palagonitic pyroclastic deposits exposed near sea level.

List of 1 Events for Episode 1

Start Date End Date Event Type Event Remarks
   - - - -    - - - - Tephra
Deformation History

There is no Deformation History data available for Isla San Luis.

Emission History

There is no Emissions History data available for Isla San Luis.

Photo Gallery

Isla San Luis, seen here from the SW with a large rhyolitic lava dome near the center, is the largest of the seven Encantada islands in the northern part of the Gulf of California. The roughly 180-m-high island lies 3 km off the eastern shore of Baja California. An older lava dome forms the NE tip of the island, and an eroded tuff ring lies at the SE tip. The lava dome seen here in the center of the island was constructed within a tuff ring and is the youngest volcanic feature.

Photo by Brian Hausback, 1997 (California State University, Sacramento).
Isla San Luis is seen here from the south with a 2-km-long spit (at low tide) to the lower left. The main features of the island are a rhyolite lava dome forming the NW tip of the island, the darker rhyolitic obsidian dome and coulee in the center, and an eroded tuff ring at the SE tip of the island (to the right). Another tuff ring, Isla Poma, lies 1 km NE of Isla San Luis and is visible to the right.

Photo by Brian Hausback, 2000 (California State University, Sacramento).
Isla San Luis lies across a narrow channel from the NE coast of Baja California (in the background). A rhyolite obsidian dome is in the center of the small island. An older dome forms the northern part of the island (foreground) and is partially mantled by ash and pumice from the central dome. An eroded tuff ring, Plaza de Toros, occupies the SE end of the island.

Photo by Keith Sutter, 2000.
The Plaza de Toros tuff ring on the SE side of Isla San Luis is seen here from the east in 2000. Remnants of dacite lava flows are visible in the upper walls of the crater. Only a third of the tuff ring is still standing; the rest has subsided along normal faults or was eroded by wave action. Longshore currents have redistributed volcanic deposits to produce the tombolo to the upper right that forms the SW tip of the island and is 2 km long at low tide.

Photo by Keith Sutter, 2000.
An obsidian lava dome fills the crater in the center of Isla San Luis, off the NE coast of Baja California, seen in this photo that was taken in 2000. As growth of the dome continued, a thick coulee advanced to the south and overflowed the rim to form the broad lobe behind it. The eroded Plaza de Toros tuff ring in the left background forms the SE tip of the island.

Photo by Keith Sutter, 2000.
GVP Map Holdings

Maps are not currently available due to technical issues.

The maps shown below have been scanned from the GVP map archives and include the volcano on this page. Clicking on the small images will load the full 300 dpi map. Very small-scale maps (such as world maps) are not included.

Smithsonian Sample Collections Database

There are no samples for Isla San Luis in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

External Sites