Karakoram fault system

Last updated
Topographical map of India and Himalaya region with Karakoram fault superimposed on top of it. Karakoram overlay modified from Location of Karakorum Fault.pdf
Topographical map of India and Himalaya region with Karakoram fault superimposed on top of it. Karakoram overlay modified from

The Karakoram fault is an oblique-slip fault system in the Himalayan region across India and Asia. The slip along the fault accommodates radial expansion of the Himalayan arc, [2] northward indentation of the Pamir Mountains, [3] and eastward lateral extrusion of the Tibetan plateau. [4] [5] Current plate motions suggest that the convergence between the Indian Plate and the Eurasian Plate is around 44±5 mm per year in the western Himalaya-Pamir region and approximately 50±2 mm per year in the eastern Himalayan region. [6]

Contents

Origin

The creation of the Karakoram fault started with the closing of the ancient Tethys ocean seaway which once separated the two modern continents of Asia and India. The Karakoram fault itself does not trace a plate boundary, except for where it possibly ends in the Indus-Yarlung Suture Zone. [4] The original thrusting occurred by linking existing thrust faults in what is now the Pamir Mountains starting between 17 and 20 million years ago.

Evolution

The Karakoram fault was a right lateral slip fault starting approximately 20 million years ago. Approximately 14 million years ago the fault changed to a predominately normal fault. This conclusion is based on argon dating. [7] Around 10-11 million years ago the Karakoram fault had become trans-tensional and extended southwest into Tibet. The southwest extension is marked by the Karakoram fault crossing the active South Kailas Thrust in the vicinity of present-day Mount Kailas. [7] [1]

Length

Karakoram fault information modified from and superimposed on top of topographic map of region. EPM= East Pamir Mountains Karakorum fault superimposed on top of topographic map.pdf
Karakoram fault information modified from and superimposed on top of topographic map of region. EPM= East Pamir Mountains

It is suggested that a late Cretaceous-Eocene granite batholith had been offset 1000 km dextrally along the Karakoram Fault [11] based on mapping in the central Karakoram, [12] [13] [14] [15] in nearby Ladakh-Zanskar, [16] and in south Tibet. Some researchers suggest that this might be incorrect due to associating granite that was never part of the same batholith. [4] Others researchers work have shown 600 km of right lateral slip since 23 million years ago, and possibly starting 34 million years ago, based on U-Pb dating. Slip in this model has been transferred into the Indus-Yalu suture zone, as well as large scale boudinage. [17] Research in the early 1990s suggested that this slip was transferred into the South Tibetan Detachment. [18] Another suggestion is that the Karakoram fault is offset at least 500 km as measured by the offset of late Paleozoic granites in the Kunlun batholith. [11] Most researchers tend to agree with the lower slip estimates. A major obstacle in measuring the total offset along the fault is in deciding what is actually a part of the fault and which faults are separate. Currently some researchers believe that the Karakoram fault merges and terminates into the Indus-Yalu suture zone at Mount Kailas. [4] Other researchers also add the Gurla Mandhata detachment, in the South-Eastern segment, to the fault. [5]

North-Western segment

The north-western segment of the Karakoram Fault is far less disputed than other areas. It terminates in the extensions of the Miuji Basin, in the Pamir Mountains, along the border between Tajikistan and Xinjiang provinces. In this north-western segment, the Karakoram Fault currently has predominantly normal fault motion, and right-lateral strike-slip offset. [4] The slip in this section of the Karakoram fault is measured to be approximately 150 km, as measured by the offset of the Aghil formation. The Aghil formation is a fossiliferous carbonate formation. Before entering the Pamir region the Karakoram fault is believed to split into two distinct faults. These faults are the main Karakoram fault itself, and the Achiehkopai fault. [10]

South-Eastern segment

Most people agree that the South-Eastern portion of the fault merges into and parallels the Indus Suture Zone in South West Tibet. The southern segment of the Karakoram Fault shows that only 120 km of dextral motion is evident from offset of geologic features, such as the Indus River and the South Kailas Thrust, [1] and that the strain in this region is almost entirely accommodated for by a north-south shortening in the Himalaya, just south of the Indus Suture Zone. [4] The Neogene Gar Basin in western Tibet also accommodates slip along the Karakoram fault. The basin lies within the northern approximately 1 km wide area of the fault, and contains listric normal faults. [9] The Gurla Mandhata fault system is thought to be encompassed within the Karakoram fault system at its southern tip, which cause the southern tip of the fault to be approximately 36 km wide. [19] Exhumation along the Gurla Mandhata detachment, which is a low-angle normal-fault system, suggest that the faults have allowed for between 36 and 66 kilometers of slip. [5]

See also

Related Research Articles

<span class="mw-page-title-main">Himalayas</span> Mountain range in Asia

The Himalayas, or Himalaya, is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the Earth's highest peaks, including the very highest, Mount Everest. Over 100 peaks exceeding 7,200 m (23,600 ft) in elevation lie in the Himalayas.

<span class="mw-page-title-main">Tibetan Plateau</span> Plateau in Central, South and East Asia

The Tibetan Plateau, also known as the Qinghai–Tibet Plateau or the Qing–Zang Plateau or as the Himalayan Plateau in India, is a vast elevated plateau located at the intersection of Central, South and East Asia covering most of the Tibet Autonomous Region, most of Qinghai, western half of Sichuan, Southern Gansu provinces in Western China, southern Xinjiang, Bhutan, the Indian regions of Ladakh and Lahaul and Spiti as well as Gilgit-Baltistan in Pakistan, northwestern Nepal, eastern Tajikistan and southern Kyrgyzstan. It stretches approximately 1,000 kilometres (620 mi) north to south and 2,500 kilometres (1,600 mi) east to west. It is the world's highest and largest plateau above sea level, with an area of 2,500,000 square kilometres (970,000 sq mi). With an average elevation exceeding 4,500 metres (14,800 ft) and being surrounded by imposing mountain ranges that harbor the world's two highest summits, Mount Everest and K2, the Tibetan Plateau is often referred to as "the Roof of the World".

<span class="mw-page-title-main">Geology of the Himalayas</span> Origins and structure of the mountain range

The geology of the Himalayas is a record of the most dramatic and visible creations of the immense mountain range formed by plate tectonic forces and sculpted by weathering and erosion. The Himalayas, which stretch over 2400 km between the Namcha Barwa syntaxis at the eastern end of the mountain range and the Nanga Parbat syntaxis at the western end, are the result of an ongoing orogeny — the collision of the continental crust of two tectonic plates, namely, the Indian Plate thrusting into the Eurasian Plate. The Himalaya-Tibet region supplies fresh water for more than one-fifth of the world population, and accounts for a quarter of the global sedimentary budget. Topographically, the belt has many superlatives: the highest rate of uplift, the highest relief, among the highest erosion rates at 2–12 mm/yr, the source of some of the greatest rivers and the highest concentration of glaciers outside of the polar regions. This last feature earned the Himalaya its name, originating from the Sanskrit for "the abode of the snow".

<span class="mw-page-title-main">Geology of Nepal</span>

The geology of Nepal is dominated by the Himalaya, the highest, youngest and a very highly active mountain range. Himalaya is a type locality for the study of on-going continent-continent collision tectonics. The Himalayan arc extends about 2,400 km (1,500 mi) from Nanga Parbat by the Indus River in northern Pakistan eastward to Namche Barwa by the gorge of the Tsangpo-Brahmaputra in eastern Tibet. About 800 km (500 mi) of this extent is in Nepal; the remainder includes Bhutan and parts of Pakistan, India, and China.

Extensional tectonics is concerned with the structures formed by, and the tectonic processes associated with, the stretching of a planetary body's crust or lithosphere.

<span class="mw-page-title-main">Transhimalaya</span> Mountain range in India and Tibet, parallel to the main Himalayan range

The Trans himalaya, or "Gangdise – Nyenchen Tanglha range", is a 1,600-kilometre-long (990 mi) mountain range in China, India and Nepal, extending in a west–east direction parallel to the main Himalayan range. Located north of Yarlung Tsangpo river on the southern edge of the Tibetan Plateau, the Transhimalaya is composed of the Gangdise range to the west and the Nyenchen Tanglha range to the east.

<span class="mw-page-title-main">Altyn Tagh fault</span>

The Altyn Tagh Fault (ATF) is a 2,000 km long, active, sinistral strike-slip fault that forms the northwestern boundary of the Tibetan Plateau with the Tarim Basin. It is one of the major sinistral strike-slip structures that together help to accommodate the eastward motion of this zone of thickened crust, relative to the Eurasian Plate. A total displacement of about ~475 km has been estimated for this fault zone since the middle Oligocene, although the amount of displacement, age of initiation and slip rate are disputed.

The 1932 Changma earthquake occurred at 10:04:27 local time on 25 December. With an estimated magnitude of 7.6 on the surface wave magnitude scale, and a maximum felt intensity of X (Extreme) on the Mercalli intensity scale, the quake destroyed 1,167 houses and caused 275 to 70,000 deaths and 320 injuries.

<span class="mw-page-title-main">Bangong suture</span>

The Bangong suture zone is a key location in the central Tibet conjugate fault zone. Approximately 1,200 km long, the suture trends in an east–west orientation. Located in central Tibet between the Lhasa and Qiangtang terranes, it is a discontinuous belt of ophiolites and mélange that is 10–20 km wide, up to 50 km wide in places. The northern part of the fault zone consists of northeast striking sinistral strike-slip faults while the southern part consists of northwest striking right lateral strike-slip faults. These conjugate faults to the north and south of the Bangong intersect with each other along the Bangong-Nujiang suture zone.

<span class="mw-page-title-main">Tectonics of the Tian Shan</span>

The Tian Shan is a mountain range in central Asia that extends through western China, Kazakhstan, and Kyrgyzstan. The Tian Shan is 2,800 kilometres (1,700 mi) long, and up to 7,400 metres (24,300 ft) high. Throughout the Tian Shan there are several intermontane basins separated by high ranges. Plate tectonic theory makes the assumption that deformation is concentrated along plate boundaries. However, active deformation is observed in the Tian Shan, far from plate boundaries. This apparent contradiction of plate tectonic theory makes the Tian Shan a key place to study the dynamics of intracontinental deformation.

<span class="mw-page-title-main">South Tibetan Detachment</span>

The South Tibetan Detachment is one of the major faults in the Himalaya Mountains.

Strain partitioning is commonly referred to as a deformation process in which the total strain experienced on a rock, area, or region, is heterogeneously distributed in terms of the strain intensity and strain type. This process is observed on a range of scales spanning from the grain – crystal scale to the plate – lithospheric scale, and occurs in both the brittle and plastic deformation regimes. The manner and intensity by which strain is distributed are controlled by a number of factors listed below.

<span class="mw-page-title-main">Himalayan foreland basin</span> Active collisional foreland basin in South Asia

The Himalayan foreland basin is an active collisional foreland basin system in South Asia. Uplift and loading of the Eurasian Plate on to the Indian Plate resulted in the flexure (bending) of the Indian Plate, and the creation of a depression adjacent to the Himalayan mountain belt. This depression was filled with sediment eroded from the Himalaya, that lithified and produced a sedimentary basin ~3 to >7 km deep. The foreland basin spans approximately 2,000 kilometres (1,200 mi) in length and 450 kilometres (280 mi) in width. From west to east the foreland basin stretches across five countries: Pakistan, India, Nepal, Bangladesh, and Bhutan.

<span class="mw-page-title-main">Pre-collisional Himalaya</span>

Pre-collisional Himalaya is the arrangement of the Himalayan rock units before mountain-building processes resulted in the collision of Asia and India. The collision began in the Cenozoic and it is a type locality of a continental-continental collision. The reconstruction of the initial configuration of the rock units and the relationship between them is highly controversial, and major concerns relate to the arrangements of the different rock units in three dimensions. Several models have been advanced to explain the possible arrangements and petrogenesis of the rock units.

<span class="mw-page-title-main">Geology of Myanmar</span>

The geology of Myanmar is shaped by dramatic, ongoing tectonic processes controlled by shifting tectonic components as the Indian plate slides northwards and towards Southeast Asia. Myanmar spans across parts of three tectonic plates separated by north-trending faults. To the west, a highly oblique subduction zone separates the offshore Indian plate from the Burma microplate, which underlies most of the country. In the center-east of Myanmar, a right lateral strike slip fault extends from south to north across more than 1,000 km (620 mi). These tectonic zones are responsible for large earthquakes in the region. The India-Eurasia plate collision which initiated in the Eocene provides the last geological pieces of Myanmar, and thus Myanmar preserves a more extensive Cenozoic geological record as compared to records of the Mesozoic and Paleozoic eras. Myanmar is physiographically divided into three regions: the Indo-Burman Range, Myanmar Central Belt and the Shan Plateau; these all display an arcuate shape bulging westwards. The varying regional tectonic settings of Myanmar not only give rise to disparate regional features, but they also foster the formation of petroleum basins and a diverse mix of mineral resources.

<span class="mw-page-title-main">Paleogeography of the India–Asia collision system</span>

The paleogeography of the India–Asia collision system is the reconstructed geological and geomorphological evolution within the collision zone of the Himalayan orogenic belt. The continental collision between the Indian and Eurasian plate is one of the world's most renowned and most studied convergent systems. However, many mechanisms remain controversial. Some of the highly debated issues include the onset timing of continental collision, the time at which the Tibetan plateau reached its present elevation and how tectonic processes interacted with other geological mechanisms. These mechanisms are crucial for the understanding of Mesozoic and Cenozoic tectonic evolution, paleoclimate and paleontology, such as the interaction between the Himalayas orogenic growth and the Asian monsoon system, as well as the dispersal and speciation of fauna. Various hypotheses have been put forward to explain how the paleogeography of the collision system could have developed. Important ideas include the synchronous collision hypothesis, the Lhasa-plano hypothesis and the southward draining of major river systems.

<span class="mw-page-title-main">Geology of Himachal Pradesh</span>

The geology of Himachal Pradesh is dominated by Precambrian rocks that were assembled and deformed during the India-Asia collision and the subsequent Himalayan orogeny. The Northern Indian State Himachal Pradesh is located in the Western Himalaya. It has a rugged terrain, with elevation ranging from 320m to 6975m. Rock materials in the region are largely from the Indian craton, and their ages range from the Paleoproterozoic to the present day. It is generally agreed that the Indian craton collided with Asia 50-60 million years ago (Ma). Rock sequences were thrust and folded immensely during the collision. The area has also been shaped by focused orographic precipitation, glaciation and rapid erosion.

<span class="mw-page-title-main">Main Himalayan Thrust</span> Geological feature

The Main Himalayan Thrust (MHT) is a décollement under the Himalaya Range. This thrust fault follows a NW-SE strike, reminiscent of an arc, and gently dips about 10 degrees towards the north, beneath the region. It is the largest active continental megathrust fault in the world.

<span class="mw-page-title-main">Main Frontal Thrust</span> Geological fault in the Himalayas

The Main Frontal Thrust (MFT), also known as the Himalayan Frontal Thrust (HFT), is a geological fault in the Himalayas that defines the boundary between the Himalayan foothills and Indo-Gangetic Plain. The fault is well expressed on the surface thus could be seen via satellite imagery. It is the youngest and southernmost thrust structure in the Himalaya deformation front. It is a splay branch of the Main Himalayan Thrust (MHT) as the root décollement.

References

  1. 1 2 3 4 Murphy, M.; A. Yin; P. Kipp; T. M. Harrison; D. Lin; J. H. Guo (2000). "Southward propagation of the Karakoram fault system, southwest Tibet: Timing and magnitude of slip" (PDF). Geology. 28 (5): 451–454. Bibcode:2000Geo....28..451M. doi:10.1130/0091-7613(2000)28<451:SPOTKF>2.0.CO;2. ISSN   0091-7613. Archived from the original (PDF) on 2013-12-02. Retrieved 2013-11-21.
  2. Murphy, M. A.; P. Copeland (2005). "Transtentional deformation in the central Himalay and its role in accommodating growth of the Himalayan orogeny". Tectonics. 24 (4): n/a. Bibcode:2005Tecto..24.4012M. doi:10.1029/2004TC001659. S2CID   106406740.
  3. Sobel, E. R.; L. M. Schoenbohm; J. Chen; R. Thiede; D. F. Stockli; M. Sudo; M. R. Strecker (2011). "Late Miocene-Pliocene deceleration of dextral slip between Pamir and Tarim: Implications for Pamir orogensis". Earth and Planetary Science Letters. 304 (3–4): 369–378. Bibcode:2011E&PSL.304..369S. doi:10.1016/j.epsl.2011.02.012.
  4. 1 2 3 4 5 6 Searle, M. P. (February 1996). "Geological evidence against large scale pre-holocene offsets along the Karakoram fault: Implications for the limited extrusion of the Tibetan Plateau". Tectonics. 15 (1): 171–186. Bibcode:1996Tecto..15..171S. doi:10.1029/95TC01693.
  5. 1 2 3 Murphy, Mike A.; A. Yin; P. Kapp; T. M. Harrison; C. E. Manning (2002). "Isotopic characteristics of the Gurla Mandhata metamorphic core complex: Implications for the architecture of the Himalayan orogen". Geology. 35 (114): 428–447. doi:10.1130/G23774A.1.
  6. Demets, C. (1990). "Current Plate Motions". Geophysical Journal International. 101 (1): 425–478. Bibcode:1990GeoJI.101..425D. doi: 10.1111/j.1365-246X.1990.tb06579.x .
  7. 1 2 Valli, Franck; Nicholas Arnaud; Phillipe Hervé Leloup; Edward R. Sobel; Gweltaz Mahe'o; Robin Lacassin; Stephane Guillot; Haibing Li; Paul Tapponnier; Zhiqin Xu (2007). "Twenty million years of continuous deformation along the Karakoram fault, Western Tibet: A Thermochronological analysis" (PDF). Tectonics. 26 (4): 1–26. Bibcode:2007Tecto..26.4004V. doi:10.1029/2005TC001913. S2CID   135348627.
  8. Searle, M. P.; R. F. Weinberg; W. J. Dunlap (1998). "Transpressional tectonics along the Karakoram fault zone, northern Ladakh: Constraints on Tibetan extrusion, in continental transpressional and transtensional tectonics". Geological Society of America Special Publication. 135: 307–326. doi:10.1144/gsl.sp.1998.135.01.20. S2CID   130363239.
  9. 1 2 Sanchez, Veronica; M. Murphy; W. R. Dupré; Lin Ding; Ran Zhang (2010). "Structural evolution of the Neogene Gar Basin, Western Tibet: Implications for releasing bend development and drainage patters". Geological Society of America Bulletin. 122 (5–6): 926–945. Bibcode:2010GSAB..122..926S. doi:10.1130/B26566.1.
  10. 1 2 Robinson, A. C. (2009). "Geologic offsets across the northern Karakorum fault: Implications for its role and terrane correlations in the western Himalayan-Tibetan orogeny" (PDF). Earth and Planetary Science Letters. 279 (1–2): 123–130. Bibcode:2009E&PSL.279..123R. doi:10.1016/j.epsl.2008.12.039.[ permanent dead link ]
  11. 1 2 Peltzer, G.; P. Tapponnier (1988). "Formation and evolution of strike-slip faults, rifts, and basins during the India-Asia collision: An experimental approach" (PDF). Journal of Geophysical Research: Solid Earth. 93 (15b): 15085–15117. Bibcode:1988JGR....9315085P. doi:10.1029/JB093iB12p15085.[ permanent dead link ]
  12. Searle, M. P.; A. J. Rex; R. Tirrul; D. C. Rex; A. Barnicoat; B.F. Windley (1989). "Metamorphic, magmatic, and tectonic evolution of the central Karakoram in the Biafo-Baltoro-Hushe regions of northern Pakistan". Tectonics of the western Himalayas. GSA Special Papers. Vol. 232. pp. 47–73. doi:10.1130/SPE232-p47. ISBN   978-0-8137-2232-0.
  13. Searle, M. P.; R.R. Parrish; R. Tirrul; D.C. Rex (1990). "Age of crystallization and cooling of the K2 gneiss in the Baltoro Karakoram". Geological Society of London. 147. 147 (4): 603–606. Bibcode:1990JGSoc.147..603S. doi:10.1144/gsjgs.147.4.0603. S2CID   129956294.
  14. Searle, M. P. (1991). Geology and Tectonics of the Karakoram Mountains. New York: John Wiley. p. 358.
  15. Searle, M. P.; R. Tirrul (1991). "Structural and thermal evolution of the Karakoram crust". Geological Society of London. 148. 148 (1): 65–82. Bibcode:1991JGSoc.148...65S. doi:10.1144/gsjgs.148.1.0065. S2CID   128818804.
  16. Searle, M. P. (1986). "Structural evolution and sequence of thrusting in the High Himalayan Tibetan Tethys and Indus suture zones of Zanskar and Ladakh, western Himalaya". Structural Geology. 8 (8): 923–936. Bibcode:1986JSG.....8..923S. doi:10.1016/0191-8141(86)90037-4.
  17. Lacassin, Robin; Frank Valli; Nicholas Arnaud; P.Hervé Leloup; Jean Louis Paquette; Li Haibing; Paul Tapponnier; Marie-Luce Chevalier; Stephane Guillot; Gweltaz Maheo; Zhiqin Xu (2004). "Large-scale geometry, offset and kinematic evolution of the Karakoram fault, Tibet" (PDF). Earth and Planetary Science Letters. 219 (3–4): 255–269. Bibcode:2004E&PSL.219..255L. doi:10.1016/S0012-821X(04)00006-8. Archived from the original (PDF) on 2013-12-03. Retrieved 2013-11-21.
  18. Pecher, A. (1991). "The contact between the Higher Himalaya crystallines and the Tibetan sedimentary series: Miocene large-scale dextral shearing". Tectonics. 10 (3): 587–598. Bibcode:1991Tecto..10..587P. doi:10.1029/90TC02655.
  19. Murphy, M.; A. Yin (2003). "Structural evolution and sequence of thrusting in the Tethyan fold-thrust belt and Indus-Yalu suture zone, southwest Tibet". Geological Society of America Bulletin. 115 (1): 21–34. Bibcode:2003GSAB..115...21M. doi:10.1130/0016-7606(2003)115<0021:SEASOT>2.0.CO;2. ISSN   0016-7606.