Tata Sabaya

Coordinates: 19°08′S 68°32′W / 19.133°S 68.533°W / -19.133; -68.533
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Tata Sabaya
Highest point
Elevation5,430 m (17,810 ft)[1]
Coordinates19°08′S 68°32′W / 19.133°S 68.533°W / -19.133; -68.533[2]
Geography
Tata Sabaya is located in Bolivia
Tata Sabaya
Tata Sabaya

Tata Sabaya is a 5,430-metre (17,810 ft) high

Salar de Coipasa salt pan
.

Volcanic activity at Tata Sabaya and elsewhere in the Central Volcanic Zone is the consequence of the subduction of the Nazca Plate beneath the South America Plate. The volcano has developed along a lineament that separates older crust north of the lineament from younger crust in the south, and the edifice has been formed by andesitic rocks.

The southern flank of Tata Sabaya

lava flows and lava domes; one eruption occurred about 6,000 years before present
.

Geography and geomorphology

Tata Sabaya lies just north of the

Salar de Coipasa in Bolivia. The small village of Pagador lies west-southwest of the volcano,[3] but the whole region is overall thinly inhabited.[4] The name means "Father Sabaya"; the term "Sabaya" may be the Aymara corruption of the Quechua term for "devil", "demon".[5] The volcano is a topic in local myths, where it is sometimes personified.[6]

Tata Sabaya is part of the

Tata Sabaya is a volcano which reaches a height of 5,430 metres (17,810 ft).

lava flows extend north from the summit and display levees and flow fronts, the flows reaching a maximum length of 2 kilometres (1.2 mi). The top of these flows is cut by a collapse scar that extends east and west of the edifice in the form of scarps up to 50 metres (160 ft) high.[9] The space between the scarps is in turn filled by more recent lava flows with a blocky appearance.[10] Farther away of the edifice, the scarp is more noticeable and reaches a height of about 200 metres (660 ft) on the southeastern side of the volcano.[8]

A 300-square-kilometre (120 sq mi) large deposit south of the volcano, originally interpreted as a

Landsat images.[8] It consists of material that forms hummock-like deposits, with individual hummocks becoming smaller the farther away from the edifice they are.[9] The deposit extends into the Salar de Coipasa where it is confined by faults[11] and is in part covered by lacustrine sediments such as tufa.[9]

  • Outline of the debris avalanche
    Outline of the debris avalanche
  • Debris avalanche profile
    Debris avalanche profile
  • Profile of volcano development
    Profile of volcano development

Geology

Off the western coast of South America, the

Southern Volcanic Zone in Chile and Argentina. These volcanic zones are separated by gaps without volcanism, where the subduction process is shallower.[16]

Several phases of tectonic and volcanic activity have been identified in the Central Volcanic Zone. An earlier phase of volcanism in the Cordillera de la Costa commenced in the Jurassic but is considered separate from the Central Volcanic Zone magmatism proper. After an erosional hiatus during the Oligocene, volcanic arc activity increased during the Miocene and culminated in a phase of strong ignimbrite eruptions,[7] which originated in calderas. This phase was associated with a substantial thickening of the crust in the Central Andes. During the Pleistocene ignimbrite volcanism waned again and stratovolcanoes began to develop.[2]

Tata Sabaya lies along a crustal transition area which separates a younger crust farther south from an older (Proterozoic) crust in the north,[2] which is made up by the Chilenia terrane and the Arequipa-Antofalla craton, respectively. This transition area appears to coincide with a chain of volcanoes that Tata Sabaya is part of and which extends from Cerro Saxani in the east to Isluga in Chile, as well as with the northern end of the Pica gap where no recent volcanism occurs in the volcanic arc.[15]

The basement of the volcano is formed by the ignimbritic Altos de Pica

formation, although outcrops of granite have been observed in the region;[15] one of these outcrops may be a Precambrian granite subsequently thermally modified in the Toarcian.[17] This basement is covered by younger volcanic rocks, alluvium and sediments of the Salar de Coipasa. Seismic tomography suggests that molten magma exists in the regional crust.[15]

Composition

Tata Sabaya has produced "two-

calc-alkaline suite. Inclusions of more mafic[a] rocks in the erupted material may indicate that mafic magma was injected into the magma chamber of Tata Sabaya.[10] The magma genesis at Tata Sabaya has been explained with magma mixing processes, which gave rise to a fairly uniform composition of the eruption products.[21]

Climate and vegetation

The region is dry with precipitation mainly falling during southern hemisphere summer, and has little vegetation cover.

Polylepis tarapacana trees grow on the slopes of Tata Sabaya; these trees form the highest woodlands in the world.[22] Other aspects of regional vegetation are the so-called puna steppe, which is characterized by grass and shrub vegetation.[23]

Eruption history

Of all volcanoes in Bolivia, Tata Sabaya is the only one with Holocene activity which is not on the border with another country.

glaciation[1] and moraines on the mountain,[8] unlike neighbouring summits.[1]

The earliest activity at Tata Sabaya constructed a pyroclastic shield, which crops out as a 20-metre (66 ft) thick sequence of block-and-ash flows fallout deposits and pumice deposits in the northern sector of the volcano.[15] Effusive eruptions then built up a volcanic cone on top of this shield; the five northerly lava flows were emplaced during this phase of activity. Some lava flows from this stage were unstable and collapsed, covering the northern parts of the volcano with debris.[24]

This effusive activity eventually oversteepened the cone, causing its southern sector to collapse. During this collapse and landsliding, large toreva blocks developed from sectors of the cone which slid down undeformed, while other material from the cone formed the hummocks in the sector collapse deposit;[9] there was no explosive eruption at the time of the collapse. The configuration of the deposit indicates that the debris entered the Salar when it was filled with water; the height of the tufa deposits imply that water levels were about 3,700 metres (12,100 ft) above sea level. This[10] and the lake terraces that the landslide overran marks the collapse as synchronous with the Lake Tauca episode 12,000-12,360 years ago[10][8] when water levels in the Salar de Coipasa reached their maximum.[25] The onset of such collapses on volcanoes is often determined by faulting, climate change or eruption of the volcano; at Tata Sabaya earthquakes and the injection of new magma has been invoked to explain the destabilization of the edifice.[12]

After the collapse, Holocene activity filled the scar with

before present, implying that the volcano may be still active.[26] Reportedly, when in 1600 Huaynaputina erupted in Peru a volcano named Sabaya erupted in Oruro and destroyed a village.[27]

Notes

References

  1. ^ a b c d de Silva et al. 1993, p. 308.
  2. ^ a b c d e f de Silva et al. 1993, p. 307.
  3. ^ de Silva et al. 1993, p. 307,308.
  4. ^
    ISSN 0375-6742
    .
  5. .
  6. ^ Gisbert, Teresa (1994). "El señorío de los Carangas y los chullpares del Río Lauca" (PDF) (in Spanish). Centro Bartolome de Las Casas. p. 433. Retrieved 7 February 2018.
  7. ^ a b de Silva et al. 1993, p. 306.
  8. ^
    S2CID 128824938
    .
  9. ^ a b c d de Silva et al. 1993, p. 313.
  10. ^ a b c d e de Silva et al. 1993, p. 315.
  11. ^ a b Deruelle, B.; Brousse, R. (2010). ""Nuee ardente" deposits at Tata Sabaya volcano (Bolivian-Chilean Andes): Pumices and lava blocks crystallization from single magma at different depths". Revista Geológica de Chile (in Spanish) (22).
  12. ^
    ISSN 0718-7106
    .
  13. ^ Clavero et al. 2006, p. 442.
  14. ^ de Silva et al. 1993, p. 305.
  15. ^ a b c d e de Silva et al. 1993, p. 309.
  16. ^ de Silva et al. 1993, p. 305,306.
  17. ISSN 0040-1951
    .
  18. ^ de Silva et al. 1993, p. 309,313,315.
  19. ^ de Silva et al. 1993, p. 315,317.
  20. ^ de Silva et al. 1993, p. 332.
  21. ISSN 1814-9332
    .
  22. .
  23. ^ de Silva et al. 1993, p. 312,313.
  24. ^ a b "Tata Sabaya". Global Volcanism Program. Smithsonian Institution.
  25. ^ Clavero et al. 2006, p. 439.
  26. .

Sources