Chaman Fault
   HOME

TheInfoList



OR:

The Chaman Fault is a major, active
geological fault In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...
in
Pakistan Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...
and
Afghanistan Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is bordere ...
that runs for over 850 km."USGS Unveils How Earthquakes Pose Risks to Afghanistan"
News Release, 30 May 2007, United States Geological Survey
Tectonically Tectonics (; ) are the processes that control the structure and properties of the Earth's crust and its evolution through time. These include the processes of mountain building, the growth and behavior of the strong, old cores of continents k ...
, it is actually a system of related geologic faults that separates the
Eurasian Plate The Eurasian Plate is a tectonic plate that includes most of the continent of Eurasia (a landmass consisting of the traditional continents of Europe and Asia), with the notable exceptions of the Indian subcontinent, the Arabian subcontinent and ...
from the
Indo-Australian Plate The Indo-Australian Plate is a major tectonic plate that includes the continent of Australia and the surrounding ocean and extends northwest to include the Indian subcontinent and the adjacent waters. It was formed by the fusion of the Indian an ...
. It is a terrestrial, primarily
transform Transform may refer to: Arts and entertainment * Transform (scratch), a type of scratch used by turntablists * ''Transform'' (Alva Noto album), 2001 * ''Transform'' (Howard Jones album) or the title song, 2019 * ''Transform'' (Powerman 5000 album ...
, left-lateral strike-slip fault. The slippage rate along the Chaman fault system as the Indo-Australian Plate moves northward (relative to the Eurasian Plate) has been estimated at 10 mm/yr or more. In addition to its primary transform aspect, the Chaman fault system has a compressional component as the
Indian Plate The Indian Plate (or India Plate) is a minor tectonic plate straddling the equator in the Eastern Hemisphere. Originally a part of the ancient continent of Gondwana, the Indian Plate broke away from the other fragments of Gondwana , began mov ...
is colliding with the Eurasian Plate. This type of plate boundary is sometimes called a transpressional boundary."Earthquakes Pose a Serious Hazard in Afghanistan"
Fact Sheet 2007–3027, April 2007, United States Geological Survey
From the south, the Chaman fault starts at the
triple junction A triple junction is the point where the boundaries of three tectonic plates meet. At the triple junction each of the three boundaries will be one of three types – a ridge (R), trench (T) or transform fault (F) – and triple junctions can b ...
where the
Arabian Plate The Arabian Plate is a minor tectonic plate in the Northern and Eastern Hemispheres. It is one of the three continental plates (along with the African and the Indian Plates) that have been moving northward in geological history and collidin ...
, the
Eurasian Plate The Eurasian Plate is a tectonic plate that includes most of the continent of Eurasia (a landmass consisting of the traditional continents of Europe and Asia), with the notable exceptions of the Indian subcontinent, the Arabian subcontinent and ...
and the
Indo-Australian Plate The Indo-Australian Plate is a major tectonic plate that includes the continent of Australia and the surrounding ocean and extends northwest to include the Indian subcontinent and the adjacent waters. It was formed by the fusion of the Indian an ...
meet, which is just off the
Makran Coast Makran ( fa, مكران), mentioned in some sources as Mecran and Mokrān, is the coastal region of Baluchistan. It is a semi-desert coastal strip in Balochistan, in Pakistan and Iran, along the coast of the Gulf of Oman. It extends westwards, f ...
of Pakistan. The fault tracks northeast across
Balochistan Balochistan ( ; bal, بلۏچستان; also romanised as Baluchistan and Baluchestan) is a historical region in Western and South Asia, located in the Iranian plateau's far southeast and bordering the Indian Plate and the Arabian Sea coastline. ...
and then north-northeast into Afghanistan, runs just to the west of
Kabul Kabul (; ps, , ; , ) is the capital and largest city of Afghanistan. Located in the eastern half of the country, it is also a municipality, forming part of the Kabul Province; it is administratively divided into 22 municipal districts. Acco ...
, and then northeastward across the right-lateral-slip Herat fault, up to where it merges with the Pamir fault system north of the 38° parallel. The Ghazaband and Ornach-Nal faults are often included as part of the Chaman fault system. South of the triple junction, where the fault zone lies undersea and extends southwest to approximately 10°N 57°E, it is known as the
Owen Fracture Zone The Owen Fracture Zone (OFZ), though misnamed a fracture zone, is a transform fault in the northwest Indian Ocean that separates the Arabian and African Plates from the Indian Plate. Extending north-northeast from where the Carlsberg Ridge meet ...
. While there is general agreement that the fault is slipping at a rate of at least 10 mm/yr, there is a report of volcanic rocks in Pakistan dated to 2 m.y. BP which have been offset such as to indicate a slip rate of 25–35 mm/yr. Offsets have been described throughout the fault in Pakistan that are young enough that "only the alluvium of the bottom of active dry washes is not displaced". The parallel mountain ranges of eastern Balochistan, (east to west) the
Kirthar Mountains The Kirthar Mountains ( ur, كوه کھیرتھر; sd, کير ٿر جبل) are a mountain range that mark the boundary between the Pakistani provinces of Balochistan and Sindh, and which comprise much of the Kirthar National Park. The mountain ra ...
, the Khude Mountains, the Zarro Mountains, the Pab Mountains and the Mor Mountains, are a result of the compressional plate boundary and are aligned parallel to the Chaman fault movement. The fault itself is west of these ranges.


Significant earthquakes along the fault

*1505, 5 July or 6th – An earthquake created a 60 km long surface rupture along a transverse fault in the Chaman system with several meters of vertical offset. This transverse fault is sometimes called the Paghman fault.Quittmeyer, R. C. and Jacob, K. H.(1979) "Historical and modern seismicity of Pakistan, Afghanistan, northwestern India, and southeastern Iran" ''Bulletin of the Seismological Society of America'' 69: pp. 773–823, p.791 *1892, 20 December –Wheeler, Russell L.; Bufe, Charles G.; Johnson, Margo L. and Dart, Richard L. (2005
"Seismotectonic map of Afghanistan, with annotated bibliography"
U.S. Geological Survey Open-File Report 2005-1264, p.9
*1935, 31 May – The 7.7 M_\mathrm 1935 Balochistan earthquake along the Ghazaband portion of the fault system killed upwards of 35,000 people. *1978, 16 March – A 6.4 M_\mathrm earthquake created a 5 km long rupture with up to 4 cm of left-lateral offset, and a smaller amount of vertical slip as the eastern wall of the fault dropped down.Yeats, R. S.; Lawrence, R. D.; Jamil-Ud-Din, Syed and Khan, S. H. (1979) "Surface effects of the 16 March 1978 earthquake, Pakistan-Afghanistan border" ''In'' Farah, Abul and DeJong, Kees A. (eds.) (1979) ''Geodynamics of Pakistan'' Geological Survey of Pakistan, Quetta, pp. 359–361


See also

*
List of faults in Pakistan This is a list of faults in Pakistan. Geology Chaman Fault The ''Chaman Fault'' is a major, active geological fault in Pakistan and Afghanistan that runs for over 850 km.
*
2008 Ziarat earthquake The 2008 Ziarat earthquakes hit the Pakistani province of Balochistan on October 29 with a moment magnitude of 6.4. The US Geological Survey reported that the first earthquake occurred north of Quetta and southeast of the Afghanistan city of Kan ...
* 2013 Balochistan earthquakes


Notes

{{reflist


External links


Photograph of the surface expression of the Chaman fault
by Hiroyuki Tsutsumi Plate tectonics Geology of Pakistan Seismic faults of Pakistan Strike-slip faults