This paper mainly discusses the timing of the Karakorum strike-slip fault, and gives a brief introduction of its structures, offset, and deformational style. This fault strikes NNW-SSE. Asymmetrical folds, stretching ...This paper mainly discusses the timing of the Karakorum strike-slip fault, and gives a brief introduction of its structures, offset, and deformational style. This fault strikes NNW-SSE. Asymmetrical folds, stretching lineation, S-C fabrics, feldspar and quartz s?-porphyroclasts, domino structure, shear cleavages and faults in the fault zone are products of tectonic movements. They all indicate a dextral slip sense of faulting. Mylonitic bands are widely developed along this fault. Phengite appears, indicating rather high deformational pressure. Geochronological data indicate that the Karakorum strike-slip faulting occurred from 6.88±0.36 to 8.75±0.25 Ma. The cumulative displacement from Muztag Ata to Muji is about 135 km.展开更多
The Permian fusulinoidean genus Monodiexodina is widely distributed in east Tethys. The genus might be an important indicator for the northern margin of Gondwana in northwestern China, but this is disputed. Monodiexod...The Permian fusulinoidean genus Monodiexodina is widely distributed in east Tethys. The genus might be an important indicator for the northern margin of Gondwana in northwestern China, but this is disputed. Monodiexodina-bearing areas can be restored as in either northern or southern middle latitudes with a symmetrical distribution between a high latitudinal, cool/cold water climatic realm and a paleotropical, warm water realm. Permian strata bearing Monodiexodina in Karakorum, Muztag Pear, and Buka Daban Pear of the east Kunlun Mountains can be correlated with each other. Faunal analyses and the stratigraphical position of Monodiexodina-bearing strata indicate that both Karakorum, east Kunlun, and the Pamirs were formed in a cool temperate sea area of the northern hemisphere in middle latitudes during the Permian, rather than at the Gondwana margin.展开更多
The Nubra valley nestled in the Karakorum Mountains of Ladakh houses about 600 glaciers of various dimensions out of which 114 glaciers were monitored in the first phase of study. The study of 114 glaciers suggests th...The Nubra valley nestled in the Karakorum Mountains of Ladakh houses about 600 glaciers of various dimensions out of which 114 glaciers were monitored in the first phase of study. The study of 114 glaciers suggests that small-sized glaciers outnumber the large-sized glaciers. Almost 52.6% of the studied glaciers are of the size less than 5 km and 31.5% of the total glaciers are between the size of 5 and 10 km. The 84 glaciers out of the 114 glaciers have been monitored on shortterm basis between the time period 1989 and 2001 whereas 30 glaciers have been monitored on long-term basis between 1969 and 2001. The monitoring of the glaciers is based on the study of Survey of India topographical sheets of 1969 and satellite imageries of time series between 1989 and 2001. The monitoring of thirty glaciers shows that 17 glaciers have lost their area between 1969 and 2001. The loss in area is from 2150 km2 in 1969 to 2026 km2 in 2001. The study of eighty- four glaciers on short-term basis between 1989 and 2001 suggests that 26 glaciers have retreated, 25 glaciers have advanced and 33 glaciers show no change during the time period. The changes in the glaciers of Nubra valley are varied and complex.展开更多
A modern research approach and working techniques in hitherto unexamined areas, produced the following results: 1). The tongues of deca- kilometre long Karakorum glaciers belong to temperate ice-streams with an an...A modern research approach and working techniques in hitherto unexamined areas, produced the following results: 1). The tongues of deca- kilometre long Karakorum glaciers belong to temperate ice-streams with an annual meltwater output. The short Aghil glaciers on the contrary are continental, arid and cold. 2). The present-day oscillations of the Karakorum glaciers are related to their own mass, and are contrary to and independent of the actual climate. Only the short glaciers, with steep tongue fronts, show a present-day positive balance. 3). C- dated Late Glacial moraines indicate14 a 400~800 m thick valley glacier at the former confluence point of the K2-, Sarpo Laggo- and Skamri glaciers. 4). From the evidence of transfluence passes with roches moutonnées, striae and the limits of glacial polishing, as well as moraines and erratics, a High Glacial at least 1200 m thick ice-stream network between the Karakorums and the Kuen Lun north slopes was reconstructed. The Shaksgam and Yarkand valleys were occupied by glaciers coming from west Tibet. The lowest-lying moraines are to be found in the foreland down to 2000 m, indicating a depression of the High Glacial (LGM) snowline (ELA) by 1300 m. 5). The approximately 10,000 measurements of the radiation balance at up to heights of 5500 m on K2 indicate that with incoming energy near the solar constant the reflection from snow- covered ice is up to 70% greater than from rock and rock waste surfaces. 6).These results confirm for the very dry western margins of Tibet an almost complete ice sheet cover in an area with subtropical energy balance, conforming with the Ice Age hypothesis of the author which is based upon the presence of a 2.4 million km2 Tibetan inland ice sheet. This inland ice developed for the first time when Tibet was uplifted over the snowline during the early Pleistocene. As the measured subtropical radiation balance shows, it was able to trigger the Quaternary Ice Ages.展开更多
Natural contents of 23 elements in soils of Karakorum-West Kunlun Mts are studied. By comparison of natural contents andcalculation of regional differentiation coefficients, similarity anddchrence of elemental content...Natural contents of 23 elements in soils of Karakorum-West Kunlun Mts are studied. By comparison of natural contents andcalculation of regional differentiation coefficients, similarity anddchrence of elemental contents between soils of the region and thatof China and of the world are discussed. Through main componentanalysis, relation of intergrowth and realignment among elementsin soils and characteristics of cluster expressed in soil types are alsodiscussed. Coherence of elements in soi1s and characteristics ofregional dtherence of the elements are clarified. The concernedregion is abound in natural resources. Research on natural contentsof chemical elements in soils of the region is significant forstudying elemental chemical geography and environmentalgeochemistry. Besides, it also offers necessary data for explorationand development of this region.展开更多
Farmer-managed irrigation systems(FMIS) in the high altitude valleys of the Karakorum,Pakistan, continue to be managed effectively despite increased pressure on the social arrangements that sustain them. Colonial era ...Farmer-managed irrigation systems(FMIS) in the high altitude valleys of the Karakorum,Pakistan, continue to be managed effectively despite increased pressure on the social arrangements that sustain them. Colonial era records shows that over a century ago government agencies undertook irrigation support projects. In the past three decades,government agencies and the non-government agency Aga Khan Rural Support Programme(AKRSP), which channels foreign funds into the region, have actively engaged in the provision of irrigation support. This article seeks to explore whether such projects support or undermine farmer-managed irrigation systems and the complex institutional arrangements that underpin them. Field research using ethnographic and participatory methods was conducted in spring 2013 in the upper Shigar valley, Skardu district, GilgitBaltistan. The findings show that irrigation development is a political activity that involves village-based actors, religious leaders, local politicians,and government and non-government agencies.Government agencies operate in a largely top-down,engineering mode, their larger projects limited to villages suffering water scarcity. The local government provides small funds for renovation work of FMIS,though allocation of funds is highly politicized. Nongovernment agencies, for a variety of reasons including donor-funding cycles, apply a one-size-fitsall ‘participatory' model in an attempt to socially engineer rules and institutions. In communities divided by factionalism the use of such external models that stress formation of committees are unlikely to yield positive results, and could instead contribute to undermining the very systems they seek to support. This research argues that irrigation interventions should take care to build upon the rich and complex social arrangements that have sustained FMIS through the centuries.展开更多
The Karakorum Fault zone(KFZ)plays an important role in understanding the formation,evolvement and deformation of the Tibetan Plateau.The high-T dextral shearing metamorphic rocks,e.g.,mylonites or mylonitized gneisse...The Karakorum Fault zone(KFZ)plays an important role in understanding the formation,evolvement and deformation of the Tibetan Plateau.The high-T dextral shearing metamorphic rocks,e.g.,mylonites or mylonitized gneisses-granites,locally crop out along the southeastern part of the KFZ in the Ayila Ri’gyüRange area.The SHRIMP U-Pb dating of the syn-kinematic crystallized zircons indicates that the initial age of the KFZ is^27 Ma,~10 Ma older than previous results.The extensive high-T dextral shearing along the KFZ started at least at 27-20 Ma,accompanied by the syn-kinematic emplacement of leuco-granites.Deformation and concomitant fluid circulation during shearing most likely occurred as early as at 25-13 Ma.The KFZ probably grew from southeast to northwest along the fault as a result of continuous convergence between the India plate and Eurasia plate.展开更多
Landslides are the most frequent geoenvironmental natural hazards in hilly regions,owing to broken rock masses and slope instability.Every year,landslides occur along the Karakorum highway in the northern section of t...Landslides are the most frequent geoenvironmental natural hazards in hilly regions,owing to broken rock masses and slope instability.Every year,landslides occur along the Karakorum highway in the northern section of the China-Pakistan Economic Corridor,involving complex geological action and causing significant damages and fatalities.To mitigate landslide hazard risks and a better understanding of landslide occurrence in steep mountainous regions,a comprehensive and precise analysis of slow-moving landslides is necessary.To address this challenge,a Multi-Temporal(MT),Interferometry Synthetic Aperture Radar(InSAR)approach using Small Baseline Subsets and Interferometric Point Target Analysis techniques was utilized to extract ground deformation rates.A total of 121 multitrack synthetic aperture radar images from Sentinel-1A were acquired from 2021 to 2023,enabling the detection and monitoring of ground displacement over time.Eight active slope movements were successfully identified by calculating the differences in deformation,indicating a significant deformation rate within the trust fault lines and regional geological formations.The research findings reveal that the regional geological structure,including lithology and fault lines,significantly increase the deformation rate.These identified landslide hazard areas range from 1.47 km2 to 14.88 km2,with an annual average rate of line of sight surface displacement estimated between−4.13 to−16.07 cm/yr.The MT-InSAR analysis demonstrates that fault lines and geology play significant role in surface deformation,providing valuable insights into the deformation induced by regional tectonic activities.展开更多
基金This study was supported by the National Natural Science Foundation of China grants 49672145 and 49902019the National Key Basic Research Project“199804800”.
文摘This paper mainly discusses the timing of the Karakorum strike-slip fault, and gives a brief introduction of its structures, offset, and deformational style. This fault strikes NNW-SSE. Asymmetrical folds, stretching lineation, S-C fabrics, feldspar and quartz s?-porphyroclasts, domino structure, shear cleavages and faults in the fault zone are products of tectonic movements. They all indicate a dextral slip sense of faulting. Mylonitic bands are widely developed along this fault. Phengite appears, indicating rather high deformational pressure. Geochronological data indicate that the Karakorum strike-slip faulting occurred from 6.88±0.36 to 8.75±0.25 Ma. The cumulative displacement from Muztag Ata to Muji is about 135 km.
基金support of the National Nature Science Foundation of China(no.:40572018)the China Geological Survey(no.:200313000054,1212010611702,1212010661312,1212010511702,and1212010561605).
文摘The Permian fusulinoidean genus Monodiexodina is widely distributed in east Tethys. The genus might be an important indicator for the northern margin of Gondwana in northwestern China, but this is disputed. Monodiexodina-bearing areas can be restored as in either northern or southern middle latitudes with a symmetrical distribution between a high latitudinal, cool/cold water climatic realm and a paleotropical, warm water realm. Permian strata bearing Monodiexodina in Karakorum, Muztag Pear, and Buka Daban Pear of the east Kunlun Mountains can be correlated with each other. Faunal analyses and the stratigraphical position of Monodiexodina-bearing strata indicate that both Karakorum, east Kunlun, and the Pamirs were formed in a cool temperate sea area of the northern hemisphere in middle latitudes during the Permian, rather than at the Gondwana margin.
文摘The Nubra valley nestled in the Karakorum Mountains of Ladakh houses about 600 glaciers of various dimensions out of which 114 glaciers were monitored in the first phase of study. The study of 114 glaciers suggests that small-sized glaciers outnumber the large-sized glaciers. Almost 52.6% of the studied glaciers are of the size less than 5 km and 31.5% of the total glaciers are between the size of 5 and 10 km. The 84 glaciers out of the 114 glaciers have been monitored on shortterm basis between the time period 1989 and 2001 whereas 30 glaciers have been monitored on long-term basis between 1969 and 2001. The monitoring of the glaciers is based on the study of Survey of India topographical sheets of 1969 and satellite imageries of time series between 1989 and 2001. The monitoring of thirty glaciers shows that 17 glaciers have lost their area between 1969 and 2001. The loss in area is from 2150 km2 in 1969 to 2026 km2 in 2001. The study of eighty- four glaciers on short-term basis between 1989 and 2001 suggests that 26 glaciers have retreated, 25 glaciers have advanced and 33 glaciers show no change during the time period. The changes in the glaciers of Nubra valley are varied and complex.
文摘A modern research approach and working techniques in hitherto unexamined areas, produced the following results: 1). The tongues of deca- kilometre long Karakorum glaciers belong to temperate ice-streams with an annual meltwater output. The short Aghil glaciers on the contrary are continental, arid and cold. 2). The present-day oscillations of the Karakorum glaciers are related to their own mass, and are contrary to and independent of the actual climate. Only the short glaciers, with steep tongue fronts, show a present-day positive balance. 3). C- dated Late Glacial moraines indicate14 a 400~800 m thick valley glacier at the former confluence point of the K2-, Sarpo Laggo- and Skamri glaciers. 4). From the evidence of transfluence passes with roches moutonnées, striae and the limits of glacial polishing, as well as moraines and erratics, a High Glacial at least 1200 m thick ice-stream network between the Karakorums and the Kuen Lun north slopes was reconstructed. The Shaksgam and Yarkand valleys were occupied by glaciers coming from west Tibet. The lowest-lying moraines are to be found in the foreland down to 2000 m, indicating a depression of the High Glacial (LGM) snowline (ELA) by 1300 m. 5). The approximately 10,000 measurements of the radiation balance at up to heights of 5500 m on K2 indicate that with incoming energy near the solar constant the reflection from snow- covered ice is up to 70% greater than from rock and rock waste surfaces. 6).These results confirm for the very dry western margins of Tibet an almost complete ice sheet cover in an area with subtropical energy balance, conforming with the Ice Age hypothesis of the author which is based upon the presence of a 2.4 million km2 Tibetan inland ice sheet. This inland ice developed for the first time when Tibet was uplifted over the snowline during the early Pleistocene. As the measured subtropical radiation balance shows, it was able to trigger the Quaternary Ice Ages.
文摘Natural contents of 23 elements in soils of Karakorum-West Kunlun Mts are studied. By comparison of natural contents andcalculation of regional differentiation coefficients, similarity anddchrence of elemental contents between soils of the region and thatof China and of the world are discussed. Through main componentanalysis, relation of intergrowth and realignment among elementsin soils and characteristics of cluster expressed in soil types are alsodiscussed. Coherence of elements in soi1s and characteristics ofregional dtherence of the elements are clarified. The concernedregion is abound in natural resources. Research on natural contentsof chemical elements in soils of the region is significant forstudying elemental chemical geography and environmentalgeochemistry. Besides, it also offers necessary data for explorationand development of this region.
基金funded by the Federal Ministry of Education and Research (BMBF), Germany
文摘Farmer-managed irrigation systems(FMIS) in the high altitude valleys of the Karakorum,Pakistan, continue to be managed effectively despite increased pressure on the social arrangements that sustain them. Colonial era records shows that over a century ago government agencies undertook irrigation support projects. In the past three decades,government agencies and the non-government agency Aga Khan Rural Support Programme(AKRSP), which channels foreign funds into the region, have actively engaged in the provision of irrigation support. This article seeks to explore whether such projects support or undermine farmer-managed irrigation systems and the complex institutional arrangements that underpin them. Field research using ethnographic and participatory methods was conducted in spring 2013 in the upper Shigar valley, Skardu district, GilgitBaltistan. The findings show that irrigation development is a political activity that involves village-based actors, religious leaders, local politicians,and government and non-government agencies.Government agencies operate in a largely top-down,engineering mode, their larger projects limited to villages suffering water scarcity. The local government provides small funds for renovation work of FMIS,though allocation of funds is highly politicized. Nongovernment agencies, for a variety of reasons including donor-funding cycles, apply a one-size-fitsall ‘participatory' model in an attempt to socially engineer rules and institutions. In communities divided by factionalism the use of such external models that stress formation of committees are unlikely to yield positive results, and could instead contribute to undermining the very systems they seek to support. This research argues that irrigation interventions should take care to build upon the rich and complex social arrangements that have sustained FMIS through the centuries.
基金Supported by the National Natural Science Foundation of China(Grant Nos.40272096 and 40572122)and China Geological Survey(Grant No.1212010610105)
文摘The Karakorum Fault zone(KFZ)plays an important role in understanding the formation,evolvement and deformation of the Tibetan Plateau.The high-T dextral shearing metamorphic rocks,e.g.,mylonites or mylonitized gneisses-granites,locally crop out along the southeastern part of the KFZ in the Ayila Ri’gyüRange area.The SHRIMP U-Pb dating of the syn-kinematic crystallized zircons indicates that the initial age of the KFZ is^27 Ma,~10 Ma older than previous results.The extensive high-T dextral shearing along the KFZ started at least at 27-20 Ma,accompanied by the syn-kinematic emplacement of leuco-granites.Deformation and concomitant fluid circulation during shearing most likely occurred as early as at 25-13 Ma.The KFZ probably grew from southeast to northwest along the fault as a result of continuous convergence between the India plate and Eurasia plate.
基金National Key R&D Program of China(2023YFE0208000)Construction Project of China Knowledge Center for Engineering Sciences and Technology(CKCEST-2023-1-5).
文摘Landslides are the most frequent geoenvironmental natural hazards in hilly regions,owing to broken rock masses and slope instability.Every year,landslides occur along the Karakorum highway in the northern section of the China-Pakistan Economic Corridor,involving complex geological action and causing significant damages and fatalities.To mitigate landslide hazard risks and a better understanding of landslide occurrence in steep mountainous regions,a comprehensive and precise analysis of slow-moving landslides is necessary.To address this challenge,a Multi-Temporal(MT),Interferometry Synthetic Aperture Radar(InSAR)approach using Small Baseline Subsets and Interferometric Point Target Analysis techniques was utilized to extract ground deformation rates.A total of 121 multitrack synthetic aperture radar images from Sentinel-1A were acquired from 2021 to 2023,enabling the detection and monitoring of ground displacement over time.Eight active slope movements were successfully identified by calculating the differences in deformation,indicating a significant deformation rate within the trust fault lines and regional geological formations.The research findings reveal that the regional geological structure,including lithology and fault lines,significantly increase the deformation rate.These identified landslide hazard areas range from 1.47 km2 to 14.88 km2,with an annual average rate of line of sight surface displacement estimated between−4.13 to−16.07 cm/yr.The MT-InSAR analysis demonstrates that fault lines and geology play significant role in surface deformation,providing valuable insights into the deformation induced by regional tectonic activities.
