Silali

Photo of this volcano
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  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 1.15°N
  • 36.23°E

  • 1528 m
    5012 ft

  • 222052
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

The Global Volcanism Program has no activity reports for Silali.

The Global Volcanism Program has no Weekly Reports available for Silali.

The Global Volcanism Program has no Bulletin Reports available for Silali.

The 30-km-wide Silali trachytic shield volcano, the largest Quaternary volcano in the northern Gregory Rift, completely straddles the East African Rift. An impressive 5 x 8 km summit caldera with 300 m deep walls is thought to have formed about 63,000 years ago. Caldera formation is thought to have been incremental, related to eruption of the Kantenmening basaltic and trachytic lava flows. A series of summit-area lava benches formed by eruptions from circumferential fissures has produced a volcano morphologically similar to Galapagos Islands volcanoes. Northern, eastern, and southern flanks are cut by a prominent broad rift zone 10-km wide and 30-km long, dotted with numerous pyroclastic cones. Lava domes on the upper eastern flank formed during the late Pleistocene and early Holocene, until about 7 ka. Youthful parasitic cones abound on the caldera floor and on the northern and NE flanks; the youngest lava flows may be little more than a few hundred years old (Williams et al. 1984). Geothermal activity occurs within the caldera and on the upper eastern flanks.

Summary of Holocene eruption dates and Volcanic Explosivity Indices (VEI).

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
5050 BCE ± 2000 years Unknown Confirmed   Ar/Ar Upper east flank
6050 BCE ± 3000 years Unknown Confirmed   Ar/Ar Eastern part of caldera
7050 BCE ± 2000 years Unknown Confirmed   Ar/Ar Upper east flank

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.


Cones

Feature Name Feature Type Elevation Latitude Longitude
Kaveterang Tuff ring 700 m 1° 14' 0" N 36° 8' 0" E

Thermal

Feature Name Feature Type Elevation Latitude Longitude
Akiloset Springs Hot Spring
Kalnang'i Springs Hot Spring
Kapedo Hot Springs Hot Spring
Lorusio Hot Springs Hot Spring
The impressive 5 x 8 km summit caldera of Silali volcano is seen in an aerial view from the SE. Formation of the 300-m-deep caldera is related to the incremental eruption of basaltic and trachytic lava flows about 63,000 years ago. N-S-trending rift valley faults cutting across the volcano can be seen at the lower left. Some of the youthful parasitic cones on the caldera floor and flanks of Silali, the largest volcano of the northern Gregory Rift, may be little more than a few hundred years old.

Photo by Martin Smith, 1993 (copyright British Geological Survey, NERC).

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.

Dunkley P N, Smith M, Allen D A, Darling W G, 1993. The geothermal activity and geology of the northern sector of the Kenya Rift Valley. Brit Geol Surv Res Rpt, SC/93/1: 1-185.

Key R M, 1987a. Geology of the Maralal area. Rpt Mines Geol Dept Kenya, 105: 1-93.

Macdonald R, Davies G R, Upton B G, Dunkley P N, Smith M, Leat P T, 1995. Petrogenesis of Silali volcano, Gregory Rift, Kenya. J Geol Soc London, 152: 703-720.

Smith M, Dunkley P N, Deino A, Williams L A J, McCall G J H, 1995. Geochronology, stratigraphy and structural evolution of Silali volcano, Gregory Rift, Kenya. J Geol Soc London, 152: 297-310.

Williams L A J, 1970. The volcanics of the Gregory Rift Valley, East Africa. Bull Volc, 34: 439-465.

Williams L A J, Macdonald R, Chapman G R, 1984. Late Quaternary caldera volcanoes of the Kenya Rift Valley. J Geophys Res, 89: 8553-8570.

Volcano Types

Shield
Caldera
Lava dome(s)
Pyroclastic cone(s)

Tectonic Setting

Rift zone
Continental crust (> 25 km)

Rock Types

Major
Trachyte / Trachyandesite
Basalt / Picro-Basalt
Minor
Trachybasalt / Tephrite Basanite

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
157
784
18,705
917,921

Affiliated Databases

Large Eruptions of Silali Information about large Quaternary eruptions (VEI >= 4) is cataloged in the Large Magnitude Explosive Volcanic Eruptions (LaMEVE) database of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).
WOVOdat WOVOdat is a database of volcanic unrest; instrumentally and visually recorded changes in seismicity, ground deformation, gas emission, and other parameters from their normal baselines. It is sponsored by the World Organization of Volcano Observatories (WOVO) and presently hosted at the Earth Observatory of Singapore.
EarthChem EarthChem develops and maintains databases, software, and services that support the preservation, discovery, access and analysis of geochemical data, and facilitate their integration with the broad array of other available earth science parameters. EarthChem is operated by a joint team of disciplinary scientists, data scientists, data managers and information technology developers who are part of the NSF-funded data facility Integrated Earth Data Applications (IEDA). IEDA is a collaborative effort of EarthChem and the Marine Geoscience Data System (MGDS).
Smithsonian Collections Search the Smithsonian's NMNH Department of Mineral Sciences collections database. Go to the "Search Rocks and Ores" tab and use the Volcano Name drop-down to find samples.