Taftan

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  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 28.6°N
  • 61.13°E

  • 3940 m
    12923 ft

  • 232050
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Bulletin Report: October 2004 (BGVN 29:10)


October 2003 visit found passive degassing; petrography of andesite lava sample

When visited in October 2003, Taftan's behavior was similar to that reported in July 1999 (BGVN 24:10), consisting of a fumarolic zone on the SE cone's W side, ~ 10 m2 in area, emitting steam and SO2 gas, and depositing sulfur. Degassing was clearly visible from the refuge at 3,250 m elevation. A mixture of sulfur and clay derived from highly altered lavas gave a snowy appearance to the summit. This snowy appearance was also noted in July 1999 (BGVN 24:10). Close to the refuge, a warm acid spring generated deep yellow deposits along the ditch down the valley for more than 1 km. A chemical analysis showed that the deposits were predominantly iron salts.

A surface lava sample, taken on 30 October 2003 from just below the refuge on the volcano's W slopes, was judged to be relatively young. George Morris analyzed the sample by X-ray fluorescence spectroscopy (XRF) and described the sample as andesite. This was the first known chemical analysis for Taftan rocks. In addition to the sampled lava flow, thick deposits of ignimbrite appeared in the walls of a deep gorge followed by the trail ascending to the refuge (at ~ 2,500 m elevation). It looked fresh and was judged to be Holocene in age.

Petrography of the lava sample. The sample is phenocryst rich (by volume, ~ 40-50% phenocrysts) in a microcrystalline to cryptocrystalline groundmass. Plagioclase is the predominant phenocryst phase (30-40%) with hornblende (< 5%), pyroxene (< 1%), opaque Fe-Ti oxide phases (< 1%), and trace amounts of biotite. Microxenoliths (1-3 mm in size) were observed, contributing < 2% volume to the whole rock.

Plagioclase phenocrysts invariably show complex zoning, but can be roughly divided into four groups. Euhedral plagioclase (0.5-1 mm long) show fine oscillatory zoning as well as internal dissolution and overgrowth surfaces. They are invariably euhedral but show no sieve-textured zones or dissolution channeling. Sieve-texture mantled plagioclase (0.5-5 mm long) can either have an un-zoned anhedral or an oscillatory zoned core. This is mantled with a zone of fine sieve-textured plagioclase of variable width, then overgrown by an un-sieved rim that may be oscillatory zoned. Inclusion-rich zones were observed running parallel to the sieve-textured zones within the cores of larger phenocrysts. Sieve-cored plagioclase (0.3-1 mm long) contain a completely sieve-textured core overgrown (normally) with an oscillatory zoned rim. These are generally smaller than the sieve-texture mantled plagioclase; however, the thicker un-sieved rims suggest that they form a distinct group rather than being a smaller version of the above. Small euhedral lath shaped plagioclase (< 0.3 mm) are common in the groundmass.

Hornblende occurs as lozenge-shaped crystals 0.2-1.5 mm long. These are invariably rimmed by thick reaction zones dominated by opaque oxides. These reaction zones can sometimes completely replace the original phenocryst.

Rare euhedral crystals of clinopyroxene were observed as phenocrysts. Similar pyroxenes were observed both in clots (with plagioclase) and in microxenoliths. Opaque oxide phases were observed as euhedral to anhedral phenocrysts 0.2-0.3 mm in diameter but account for less than 1% of the whole rock. Trace amounts of biotite were also observed; similar biotite was seen in microxenoliths. Most microphenocrysts contained a microcrystalline mass dominated by opaque oxides. Where less altered examples survive, the mineralogy is dominated by subhedral plagioclase and euhedral clinopyroxene, the pyroxene often partially altered to biotite and oxide phases. Crystal faces on feldspar in contact with the groundmass show sieve-textured reaction mantles, which is absent on crystal faces internal to the microxenoliths.

Interpretation. The phenocryst assemblage of the lava sample suggests multiple phenocryst sources and disequilibrium between mineral phases and groundmass, typical of stratovolcanoes. The correspondence of some phenocryst phases with mineral phases in microxenoliths suggest that at least some of the phenocrysts were inherited during the assimilation of country rock, while the oscillatory zoning, sieve-textured cores and mantles, and multiple dissolution surfaces in feldspars indicates that other phenocrysts have undergone long and complex magmatic histories.

Setting and summit elevation. Taftan is in eastern Iran, 100 km SSE of the city of Zahedan and 50 km W of the Pakistan border. Several necks, representing erosional remnants of cinder cones, rise from the plain W from Taftan, as well as a second stratovolcano, Buzman (~ 3,500 m summit elevation), which remains largely unknown.

The summit elevation is listed in the Catalog of Active Volcanoes of the World (Gansser, 1964) as 4,050 m. Jean Sesiano found (presumably more current) Iranian maps with the volcanically active SE summit shown as 3,940 m, and the dissected NW summit, as 3,840 m.

Reference. Gansser, A., 1964, Catalog of the Active Volcanoes and Solfatara Fields of Iran; Rome, IAVCEI, part XVII-Appendix, p. 1-20.

Information Contacts: Jean Sesiano and George Morris, Earth Sciences Section, Mineralogy Dept, University of Geneva, 13 rue des Maraîchers, 1205 Genève, Switzerland

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

Index of Bulletin Reports


Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

04/1993 (BGVN 18:04) Lava flow reported; no previous historical eruptions known

10/1999 (BGVN 24:10) Visitors note mineral springs and fumaroles

10/2004 (BGVN 29:10) October 2003 visit found passive degassing; petrography of andesite lava sample




Bulletin Reports

All information contained in these reports is preliminary and subject to change.


04/1993 (BGVN 18:04) Lava flow reported; no previous historical eruptions known

An eruption that sent a lava flow ~60 m downslope was reported on 25 April by the Islamic Republic News Agency. No additional information about the timing or location of the activity was available. There was apparently no immediate danger to the local population.

Information Contacts: AP; Reuters.
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10/1999 (BGVN 24:10) Visitors note mineral springs and fumaroles

In response to reported fumarolic activity near the summit, a group from the Societe de Volcanologie Geneve ascended the summit on 27 July 1999. The activity focused at a solfatara 1.5 x 5 m in size with several openings emitting SO2-rich vapor plumes. The surrounding area resembled a snowcap despite consisting entirely of sulfur and clay.

During the ascent clear water was seen at 3,220 m elevation almost 800 m below the summit. At about the 3,240 m elevation, a spring was discovered pouring from the flank of the volcano. The water in the spring reached a temperature of nearly 30°C and a pH of 1. The spring water created a white-yellowish deposit which darkened as it dried. The dried deposits were colored sharp yellow to dark orange. Despite their color, these deposits were not formed from sulfur, but rather from iron chlorides. When redissolved back in water, a colorless solution resulted.

Information Contacts: D. Zurcher and R. Haubrichs, Societe de Volcanologie Geneve (SVG), C.P. 6423, CH-1211, Geneve 6, Switzerland (Bulletin de la SVG, October 1999, p. 6 (in French)).
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10/2004 (BGVN 29:10) October 2003 visit found passive degassing; petrography of andesite lava sample

When visited in October 2003, Taftan's behavior was similar to that reported in July 1999 (BGVN 24:10), consisting of a fumarolic zone on the SE cone's W side, ~ 10 m2 in area, emitting steam and SO2 gas, and depositing sulfur. Degassing was clearly visible from the refuge at 3,250 m elevation. A mixture of sulfur and clay derived from highly altered lavas gave a snowy appearance to the summit. This snowy appearance was also noted in July 1999 (BGVN 24:10). Close to the refuge, a warm acid spring generated deep yellow deposits along the ditch down the valley for more than 1 km. A chemical analysis showed that the deposits were predominantly iron salts.

A surface lava sample, taken on 30 October 2003 from just below the refuge on the volcano's W slopes, was judged to be relatively young. George Morris analyzed the sample by X-ray fluorescence spectroscopy (XRF) and described the sample as andesite. This was the first known chemical analysis for Taftan rocks. In addition to the sampled lava flow, thick deposits of ignimbrite appeared in the walls of a deep gorge followed by the trail ascending to the refuge (at ~ 2,500 m elevation). It looked fresh and was judged to be Holocene in age.

Petrography of the lava sample. The sample is phenocryst rich (by volume, ~ 40-50% phenocrysts) in a microcrystalline to cryptocrystalline groundmass. Plagioclase is the predominant phenocryst phase (30-40%) with hornblende (< 5%), pyroxene (< 1%), opaque Fe-Ti oxide phases (< 1%), and trace amounts of biotite. Microxenoliths (1-3 mm in size) were observed, contributing < 2% volume to the whole rock.

Plagioclase phenocrysts invariably show complex zoning, but can be roughly divided into four groups. Euhedral plagioclase (0.5-1 mm long) show fine oscillatory zoning as well as internal dissolution and overgrowth surfaces. They are invariably euhedral but show no sieve-textured zones or dissolution channeling. Sieve-texture mantled plagioclase (0.5-5 mm long) can either have an un-zoned anhedral or an oscillatory zoned core. This is mantled with a zone of fine sieve-textured plagioclase of variable width, then overgrown by an un-sieved rim that may be oscillatory zoned. Inclusion-rich zones were observed running parallel to the sieve-textured zones within the cores of larger phenocrysts. Sieve-cored plagioclase (0.3-1 mm long) contain a completely sieve-textured core overgrown (normally) with an oscillatory zoned rim. These are generally smaller than the sieve-texture mantled plagioclase; however, the thicker un-sieved rims suggest that they form a distinct group rather than being a smaller version of the above. Small euhedral lath shaped plagioclase (< 0.3 mm) are common in the groundmass.

Hornblende occurs as lozenge-shaped crystals 0.2-1.5 mm long. These are invariably rimmed by thick reaction zones dominated by opaque oxides. These reaction zones can sometimes completely replace the original phenocryst.

Rare euhedral crystals of clinopyroxene were observed as phenocrysts. Similar pyroxenes were observed both in clots (with plagioclase) and in microxenoliths. Opaque oxide phases were observed as euhedral to anhedral phenocrysts 0.2-0.3 mm in diameter but account for less than 1% of the whole rock. Trace amounts of biotite were also observed; similar biotite was seen in microxenoliths. Most microphenocrysts contained a microcrystalline mass dominated by opaque oxides. Where less altered examples survive, the mineralogy is dominated by subhedral plagioclase and euhedral clinopyroxene, the pyroxene often partially altered to biotite and oxide phases. Crystal faces on feldspar in contact with the groundmass show sieve-textured reaction mantles, which is absent on crystal faces internal to the microxenoliths.

Interpretation. The phenocryst assemblage of the lava sample suggests multiple phenocryst sources and disequilibrium between mineral phases and groundmass, typical of stratovolcanoes. The correspondence of some phenocryst phases with mineral phases in microxenoliths suggest that at least some of the phenocrysts were inherited during the assimilation of country rock, while the oscillatory zoning, sieve-textured cores and mantles, and multiple dissolution surfaces in feldspars indicates that other phenocrysts have undergone long and complex magmatic histories.

Setting and summit elevation. Taftan is in eastern Iran, 100 km SSE of the city of Zahedan and 50 km W of the Pakistan border. Several necks, representing erosional remnants of cinder cones, rise from the plain W from Taftan, as well as a second stratovolcano, Buzman (~ 3,500 m summit elevation), which remains largely unknown.

The summit elevation is listed in the Catalog of Active Volcanoes of the World (Gansser, 1964) as 4,050 m. Jean Sesiano found (presumably more current) Iranian maps with the volcanically active SE summit shown as 3,940 m, and the dissected NW summit, as 3,840 m.

Reference. Gansser, A., 1964, Catalog of the Active Volcanoes and Solfatara Fields of Iran; Rome, IAVCEI, part XVII-Appendix, p. 1-20.

Information Contacts: Jean Sesiano and George Morris, Earth Sciences Section, Mineralogy Dept, University of Geneva, 13 rue des Maraîchers, 1205 Genève, Switzerland
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Taftan is a strongly eroded andesitic stratovolcano with two prominent summits. The volcano was constructed along a volcanic zone in Beluchistan, SE Iran, that extends into northern Pakistan. The higher, 3940-m SE summit cone is well preserved and has been the source of very fresh-looking lava flows. Highly active, sulfur-encrusted fumaroles occur at the summit of the SE cone. The deeply dissected NW cone is of Pleistocene age. In January 1902 the volcano was reported to be smoking heavily for several days, with occasional strong night-time glow. A lava flow was reported at Taftan in 1993, but may have been a mistaken observation of a molten sulfur flow.

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

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
[ 1993 Apr 25 ] [ Unknown ] Uncertain    
[ 1902 Jan ] [ Unknown ] Uncertain    

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.


Synonyms

Kuh-e Taftan | Koh-i Taftan | Kuh-i-Daftan | Daftan
Snow-capped Taftan volcano towers above surrounding arid terrain in eastern Iran. The strongly eroded stratovolcano has two prominent summits. The volcano was constructed along a volcanic zone in Beluchistan, SE Iran, that extends into northern Pakistan. The higher, 4050 m SE summit cone is well preserved and has been the source of very fresh-looking lava flows. Highly active, sulfur-encrusted fumaroles occur at the summit of the SE cone.

NASA Space Shuttle image STS80-752-40, 1996 (http://eol.jsc.nasa.gov/).

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.

Blumenthal M M, van der Kaaden G, Vlodavetz V I, 1964. Turkey & Caucasus. Catalog of Active Volcanoes of the World and Solfatara Fields, Rome: IAVCEI, 17: 1-23.

Ermann O, 2006. . (pers. comm.).

Karakhanian A, Djrbashian R, Trifonov V, Philip H, Arakelian S, Avagian A, 2002. Holocene-historical volcanism and active faults as natural risk factors for Armenia and adjacent countries. J Volc Geotherm Res, 113: 319-344.

Katsui Y (ed), 1971. List of the World Active Volcanoes. Volc Soc Japan draft ms, (limited circulation), 160 p.

Lander A H S, 1902. Across Coveted Lands or a Journey from Flushing (Holland) to Calcutta Overland. London: MacMillan and Co., 2 volumes.

Shakeri A, Moore F, Kompani-Zare M, 2008. Geochemistry of the thermal springs of Mount Taftan, southeastern Iran. J Volc Geotherm Res, 178: 829-836.

Smithsonian Institution-GVN, 1990-. [Monthly event reports]. Bull Global Volc Network, v 15-33.

Volcano Types

Stratovolcano
Caldera

Tectonic Setting

Intraplate
Continental crust (> 25 km)

Rock Types

Major
Andesite / Basaltic Andesite

Population

Within 5 km
Within 10 km
Within 30 km
Within 100 km
8
132
8,118
191,711

Affiliated Databases

Large Eruptions of Taftan 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.