Western Ladakh Research Articles

On the occurrence of Sorbus tianschanica Rupr. (Rosaceae), a climate relict from Ladakh, Indian Trans Himalaya

ABSTRACT A new distribution record of Sorbus tianschanica Rupr., a tree or shrub native to the temperate northern hemisphere, is reported for Ladakh. Thirty-one individuals of S. tianschanica were seen growing on exposed cliffs and also on shadowed cliff bases in a remote valley in the western Ladakh region of Kargil. A detailed taxonomic description, diagnostic features and notes on the habitat of the species along with its distribution and climatic range in the adjacent phytogeographic regions (Gilgit-Baltistan, Tajikistan, Kyrgyzstan, Kazakhstan and some provinces of China) are provided. Further, information on the species palaeoecology and biogeography has been reviewed, and its conservation significance is discussed. Our findings emphasise the importance of keeping records of local biodiversity up to date. This is critical for implementing global biodiversity policies and meeting conservation goals.

Glacier mass balance and its climatic and nonclimatic drivers in the Ladakh region during 2000–2021 from remote sensing data

Abstract This study investigates the geodetic mass balance of nearly all glaciers in the Ladakh region, which are crucial for local water security. Utilizing multiple digital elevation models from 2000 and 2021, we estimate glacier mass balances. Climatic drivers of glacier mass balances are explored using ERA5-Land reanalysis data, evaluated by in situ climate data. The study also examines the role of nonclimatic (morphological) variables on glacier mass balances. Results indicate Ladakh glaciers experienced negative mass balances during 2000–2021, with significant spatial variability. Western Ladakh glaciers lost slightly higher mass (−0.35 ± 0.07 to −0.37 ± 0.07 m w.e. a−1) than eastern Ladakh glaciers (−0.21 ± 0.07 to −0.33 ± 0.05 m w.e. a−1). While warming is the main driver of widespread mass loss in Ladakh, the spatial variability in mass loss is attributed to changes in regional precipitation and glacier morphological settings. Eastern Ladakh glaciers, being smaller and at higher elevations, experience lower mass loss, whereas western Ladakh glaciers, larger and at lower elevations, are more susceptible to the impact of temperature, resulting in higher mass loss. The study underscores the potentially greater vulnerability of western Ladakh glaciers to a warming climate compared to their eastern counterparts.

Harmony in nature: understanding the cultural and ecological aspects of plant use in Ladakh

BackgroundTraditional knowledge (TK) in Ladakh encapsulates a repository of experimental wisdom cultivated over millennia. Despite this cultural wealth, dwindling interest among the younger generations in the region’s age-old practices underscores the urgency to document TK. The current study investigates the diverse usage of plants in Surru, Wakha and Lower Indus valleys of Western Ladakh exploring the influence of socioeconomic and ecological factors.MethodsA stratified random sample approach was adopted to select 540 respondents for gathering information of useful plants through interviews and questionnaires. Participant observation, questionnaires, open-ended and semi-structured interviews were conducted for data collection. Free listing was done to create an extensive list of plants and their uses. Ethnobotanical metrics such as relative frequency of citation (RFC), relative importance index (RI), cultural value (CV) index and cultural importance (CI) index were computed to assess species applicability. Additionally, one-way analysis of variance (ANOVA) was utilized to discern significant differences in knowledge levels based on valleys, gender, education and religion using TK as a response variable.ResultsAltogether, we recorded 246 plant species under various ethnobotanical uses from Western Ladakh. These include medicinal (126), fodder (124), wild ornamentals (86), food (81), fuel wood (54), dye (20), religious (31) and others (34). Novel plant reports include Berberis brandisiana Ahrendt and Dactylorhiza kafiriana Renz. The dominant plant family is Asteraceae with 35 species. Suru valley exhibits the highest number of cited plants followed by Wakha-chu and Lower Indus valleys (192, 168 and 152 species, respectively).ConclusionDisparities in plant use understanding are evident among different groups, prompting further investigation through intercultural comparisons. Plants such as Arnebia euchroma, Juniperus semiglobosa, and Artemisia species emerge with cultural importance. Gender, valley affiliation, religious background and the remoteness of a village all influence local plant knowledge. These variations are linked to socioeconomic disparities among communities.

Perception of medical health care practitioners and health care consumers towards traditional health care systems in western Ladakh, India

Background: This study focussed on the perception of Medical Health Care Professionals (MHCPs) and Local Health Care Consumers (LHCCs) on traditional health-care systems (THCS) and collaboration of both traditional and modern health-care system in western Ladakh, India. Methods: The study area was based on the distribution of three different socio-cultural groups in three valleys (Lower Indus, Suru and Wakha Chu) in western Ladakh. A detailed field investigation was undertaken for the perception, which involved semi-structured questionnaire survey of 30 MHCPs and 540 LHCCs, to document their opinion regarding integration of traditional and modern medicine. Results: Although local communities comprehend health problems and solutions within their cultural frame of reference but now it has changed over the years. The majority of MHCPs and LHCCs were agreed on the collaboration of both the health care systems. Conclusions: Of all the THCS the Amchi system seems to be the most scientific and therefore the most logical one to be integrated into the modern medicine system. Keywords: Age class, Amchi system, Akhons, Shamans Lower Indus valley, Sowa-rigpa, Suru-valley

Geochemistry and petrogenesis of ophiolitic rocks from the Indus Suture Zone (ISZ), Ladakh Himalaya: insights for depleted mantle beneath an intra-oceanic island arc complex

ABSTRACT The Indus Suture Zone preserves the ophiolitic remnants of the eastern part of the Neo-Tethys Ocean. Parts of these ophiolitic remnants are exposed along the Khangral-Chiktan and Dras-Kargil road sections of western Ladakh. The observed rock types include ultramafic-mafic cumulates, gabbros, and volcanics emplaced as faulted blocks over the Mesozoic Dras arc complex. Geochemically, these rocks show sub-alkaline tholeiitic characteristics with basalt to basaltic-andesite compositional variation. Based on modal mineralogy, the ultramafic cumulates classify as olivine-websterite, the mafic cumulates as olivine-norite, and the gabbros as norite to hornblende-gabbro. The ultramafic cumulates depict depleted chondrite normalized REE patterns [(La/Yb)N = 0.6–1.1] while the mafic cumulates display depleted to enriched REE patterns [(La/Yb)N = 0.6–3.2]. Fractionated patterns are observed in gabbros [(La/Yb)N = 1.6–4.1], while flat and enriched chondrite normalized REE-patterns in volcanics [(La/Yb)N = 1.0–12.3] similar to NMORB, and EMORB. The multi-element patterns depict subduction-related geochemical characteristics such as enriched LILE and depleted HFSE compared to the primitive mantle. Presence of Mg-rich olivines, orthopyroxenes, and clinopyroxenes while Ti-poor clinopyroxenes in ultramafic-mafic cumulates reflect their derivation from previously depleted mantle sources at high-pressure and temperature comparable to the base of modern intra-oceanic island arc tholeiitic sequences. The studied rocks exhibit close similarity to an intra-oceanic subduction system contemporaneous to the Dras-Shergol-Suru-Thasgam ophiolitic slices of western Ladakh.

Prevailing traditional health care services in Western Ladakh, Indian Trans-Himalaya

Background: There has been a spurt in revival of Traditional Health Care Services (THCS) in different parts of the world due to increasing awareness about their importance and the initiatives taken by the local governments. Ladakh, located in the Indian Trans-Himalaya represents an ethno-cultural landscape with well-established history of use of traditional medicines in healing of different ailments. However, several THCS so far remained informal and have not been documented properly. The present study aimed to assess and document the status of three different THCS viz., Amchis, Akhons and Shamans in western Ladakh. Methods: Both qualitative and quantitative data about the 36 Amchis, 53 Akhons and 21 Shamans was collected through questionnaire surveys, semi-structured interviews and participatory appraisals in three valleys of western Ladakh were organized. Results: The Amchis and Akhons were mostly middle aged and older men while Shamans were mostly young women. All the three healers were generally illiterate with weak socio-economic status. Amchis and Akhons were more experienced as it was their main profession and received the knowledge hereditary. Amchis and Shamans were mostly Buddhist while Akhons were Muslim. These traditional healers treated 17 different ailments. Conclusion: The local population of the western Ladakh reported that most of the sub-centers and primary health centers lack medical equipment, drugs, and skilled workforce. Due to deficiencies in health care services the use of indigenous healthcare practices is common. Efforts should be made to fortify THCS by collaborating with modern medicine systems to improved local health care. Of all the THCS, the Amchi system or Sowa-rigpa seems to be the most codified and might therefore be the most logical one to be integrated into the public health care system. Keywords: Traditional health care system, Amchi, Akhon, Shaman, Western Ladakh

Non-silicate needles and metals in peridotites from Himalayan ophiolite, Western Ladakh, India: evidence of deep Earth origin

Non-silicate needles and metals in peridotites from Himalayan ophiolite, Western Ladakh, India: evidence of deep Earth origin

Petrological and geochemical characterization of the arc-related Suru–Thasgam ophiolitic slice along the Indus Suture Zone, Ladakh Himalaya

AbstractThe Ladakh Himalayan ophiolites preserve remnants of the eastern part of the Neo-Tethyan Ocean, in the form of Dras, Suru Valley, Shergol, Spongtang and Nidar ophiolitic sequences. In Kohistan region of Pakistan, Muslim Bagh, Zhob and Bela ophiolites are considered to be equivalents of Ladakh ophiolites. In western Ladakh, the Suru–Thasgam ophiolitic slice is highly dismembered and consists of peridotites, pyroxenites and gabbros, emplaced as imbricate blocks thrust over the Mesozoic Dras arc complex along the Indus Suture Zone. The Thasgam peridotites are partially serpentinized with relict olivine, orthopyroxene and minor clinopyroxene, as well as serpentine and iron oxide as secondary mineral assemblage. The pyroxenites are dominated by clinopyroxene followed by orthopyroxene with subordinate olivine and spinel. Gabbros are composed of plagioclase and pyroxene (mostly replaced by amphiboles), describing an ophitic to sub-ophitic textural relationship. Geochemically, the studied rock types show sub-alkaline tholeiitic characteristics. The peridotites display nearly flat chondrite-normalized rare earth element (REE) patterns ((La/Yb)N = 0.6–1.5), while fractionated patterns were observed for pyroxenites and gabbros. Multi-element spidergrams for peridotites, pyroxenites and gabbros display subduction-related geochemical characteristics such as enriched large-ion lithophile element (LILE) and depleted high-field-strength element (HFSE) concentrations. In peridotites and pyroxenites, highly magnesian olivine (Fo88.5-89.3 and Fo87.8-89.9, respectively) and clinopyroxene (Mg no. of 93–98 and 90–97, respectively) indicate supra-subduction zone (SSZ) tectonic affinity. Our study suggests that the peridotites epitomize the refractory nature of their protoliths and were later evolved in a subduction environment. Pyroxenites and gabbros appear to be related to the base of the modern intra-oceanic island-arc tholeiitic sequence.

PGE and isotopic characteristics of Shergol and Suru Valley Ophiolites, Western Ladakh: Implications for supra-subduction tectonics along Indus Suture Zone

Present study reports the PGE-geochemistry of mantle peridotites and Nd-isotope geochemistry of arc related mafic rocks from the Indus Suture Zone (ISZ), western Ladakh. The total PGE concentration of the Shergol and Suru Valley peridotites (∑PGE = 96–180 ppb) is much higher than that of the primitive mantle and global ophiolitic mantle peridotites. The studied peridotites show concave upward PGE-distribution patterns with higher palladium-group PGE/Iridium-group PGE ratios (i.e., 0.8–2.9) suggesting that the partial melting is not the sole factor responsible for the evolution of these peridotites. The observed PGE-distribution patterns are distinct from residual/refractory mantle peridotites, which have concave downward or flat PGE-distribution patterns. Relative enrichment of palladium-group PGE as well as other whole-rock incompatible elements (e.g., LILE and LREE) and higher Pd/Ir ratio (1.1–5.9) reflects that these peridotites have experienced fluid/melt interaction in a supra-subduction zone (SSZ) tectonic setting. Also, the Shergol mafic intrusives and Dras mafic volcanics, associated with the studied peridotites, have high 143Nd/144Nd ratios (i.e., 0.512908–0.513078 and 0.512901–0.512977, respectively) and positive εNd(t) (calculated for t = 140 Ma) values (i.e., +5.3 to +8.6 and + 5.1 to +6.6, respectively), indicating derivation from depleted mantle sources within an intra-oceanic arc setting, similar to Spongtang and Nidar ophiolites from other parts of Ladakh Himalaya. The transition from SSZ-type Shergol and Suru Valley peridotites to Early Cretaceous tholeiitic Shergol mafic intrusives followed by tholeiitic to calc-alkaline Dras mafic volcanics within the Neo-Tethys Ocean exhibit characteristics of subduction initiation mechanism analogous to the Izu-Bonin-Mariana arc system within western Pacific.

Petrology and Geochemistry of Mafic Intrusive Rocks from the Sapi-Shergol Ophiolitic Mélange, Indus Suture Zone, Western Ladakh: Constraints on Petrogenesis and Tectonic Setting

This article reports the existence of subduction-related tholeiitic, normal mid-ocean ridge basalt (N-MORB)-type mafic intrusives emplaced within the Sapi-Shergol ophiolitic mélange of the Indus Suture Zone, western Ladakh. The Shergol mafic intrusives show Fe enrichment with basalt to basaltic-andesite composition. Based on their mineralogy and textures, these mafic rocks can be identified as fine- to medium-grained gabbros that have undergone greenschist-grade metamorphism. These rocks have N-MORB-type geochemical characteristics, exhibiting nearly flat to depleted light rare earth element patterns ((La/Sm)N=0.66–1.05). Petrogenetic modeling suggests <20% partial melting of a depleted MORB-type mantle source, within the spinel peridotite stability. The presence of slightly negative anomalies of high field strength elements like Nb, Zr, and Ti in multielement patterns reflect the influence of subduction zone magmatism. The presence of low-Ti clinopyroxene (En38–50Fe11–25Wo31–43; enstatite-ferrosilite-wollastonite), Ca-rich plagioclase (An2–36; andesine), and pargasitic amphibole also reflects their subduction-related depleted-mantle origin. The MORB–island arc tholeiite signature displayed by the Shergol gabbros intrusive in Shergol peridotites reflect their generation in a mantle wedge associated with the Early Cretaceous intraoceanic subduction within the Neo-Tethys Ocean. They are similar to Spongtang ophiolite gabbros intrusive in the Spongtang ophiolite mantle peridotites from south Ladakh, ophiolitic mélange gabbros from southern Tibet, and Muslim Bagh ophiolite gabbros from Pakistan. Based on this study, we offer a geodynamic model suggesting that the Sapi-Shergol ophiolitic slice was intruded by mafic intrusive rocks that represent the relict of the intraoceanic substratum of the Cretaceous Dras arc complex.

The tectonic evolution of the Dras arc complex along the Indus Suture Zone, western Himalaya: Implications for the Neo-Tethys Ocean geodynamics

In this study we present new whole-rock geochemical data on the Dras arc complex exposed along the Dras–Kargil National Highway, western Ladakh. This complex forms a part of the Indus Suture Zone, which is a major tectonic unit extending along the Himalaya from the Pakistan in the west to the Tibet in the east. The Dras arc complex is dominated by mafic volcanics, with subordinate gabbros at the base exposed near Kargil. The Dras volcanics have augite and plagioclase phenocrysts embedded in a groundmass of plagioclase and pyroxene with porphyritic, intergranular and ophitic textural relationships. Also chlorite and epidote are present as secondary mineral assemblage in these volcanics. Plagioclase and pyroxene are the dominant mineral assemblage in the Kargil gabbro, with minor amounts of oxides and relict olivine. These rock types are characterized by ophitic textures and are devoid of any secondary mineral assemblage when compared to the mafic volcanics, which have suffered greenschist metamorphism. Geochemically, the Dras volcanics and the Kargil gabbros are classified as sub-alkaline tholeiites and show a compositional variation from basalt to basaltic andesite. On a Nb/Yb vs. Th/Yb diagram, they fall within the compositional field of arc-related rocks. NMORB-normalized multi-element patterns shows enrichment in large ion lithophile elements (e.g., Rb, Ba, Th, U, K and Pb) and light rare earth elements (LREE), but a depletion in high field strength elements (e.g., Nb, P, Zr and Ti), which supports a subduction-related origin. Lower Ba/La and La/Yb ratios indicate contribution from fluid fluxing, rather than slab melts to the mantle wedge. The Dras volcanics show similar geochemical trends to volcanic arc rocks from the Nidar and the Spongtang ophiolite complex of the Ladakh Himalaya as well as the Hasanbag and Kata Rush arc rocks from the Iraqi Zagros Suture, having similar age relationships in the context of the Neo-Tethys Ocean.

Residues of Ancient Beliefs among the Shin in the Gilgit-Division and Western Ladakh

The Gilgit-Division (northern Pakistan) and the Dah-Hanu area (the westernmost part of Ladakh, India) have always been difficult to access. This is due in part to the mountainous terrain, which is made even more treacherous by the prevailing security instability (certain areas are still off limits for foreigners due to the Kashmir conflict). Hence, there has been very little anthropological research undertaken in this area over the last 50 years. The present paper attempts to revive the interest in these neglected regions by examining ancient traits of shamanism, as well as the worship of pre-Islamic and pre-Buddhist deities, still prevailing around Gilgit and in the Dah-Hanu area. Furthermore, this study sheds light on the history, culture and religion of the Shin people. It does so by elaborating on the changes the old Dardic belief system underwent in order to adapt to the missionary efforts of “world-religions” conquering the region. Finally, this work attempts to explain and date the different Shin-migrations, which took these people from their homesteads in Kohistan to the Gilgit region and from there to the Dah-Hanu area. The research is based on interviews carried out by the author in Gilgit, Bagrot, Hunza and Nagar, as well as in the Dah-Hanu area (15 male and 15 female shamans; 6 male priests, and numerous villagers) between 2011 and 2013. In addition, the author witnessed the very rare initiation of a male shaman in Lower Hunza. He further observed two shamanic séances in the Dah-Hanu area.

Changing aspects of Traditional Healthcare System in Western Ladakh, India

Ethnopharmacological relevanceThe Sowa-rigpa system of traditional healing has been practiced from time immemorial in western Ladakh but its existence is in jeopardy today. Documentation of information on various aspects of this system such as treatment methods, materials used for medicine and socio-cultural aspects is needed to ensure the long-term survival of this system. Materials and methodsExtensive field surveys were conducted from March 2009 to June 2011 in three different Valleys of the Kargil district. Interviews with traditional healers, village heads and local people were conducted using semi-structured questionnaires and participatory observations to assess the current status of traditional medicine system. Plant specimens were collected from the field for identification and herbarium preparation which were later deposited in herbaria for future reference. Results160 plants were recorded to be used by traditional healers of Western Ladakh. Traditional healing system (THS) is taking care of 30% of public healthcare. Only 36 traditional healers are left in this region of which 67% was found along the Wakha-chu Valley, followed by the Lower Indus Valley (17%) and the SuruValley (16%). The transfer of knowledge to the next generation is very low (25%) in Kargil. Low income and continuously deteriorating social status of healers has contributed to the decline of this system. ConclusionsLack of interest in young generation in adopting this system may pose a threat to the survival of Sowa-rigpa. Integration of this system with the modern healthcare system and more government support may prove effective to enhance its deteriorating conditions.

Sedimentation pattern in a trans-Himalayan Quaternary lake at Lamayuru (Ladakh), India

Located on the Indo-Tsangpo Suture Zone, Lamayuru Lake in western Ladakh was created by neotectonic instability around 35–40 ka. The valley fill sequence, about 110 m thick, reveals an interplay of lacustrine to fluvio-deltaic to colluvial processes operating in response to changing climate and tectonic conditions. Based on integrated approach of sedimentology and palaeontological analysis, we propose a sedimentation model for Lamayuru Lake with reference to changing climatic conditions and neotectonics. The coarsening upward succession was divided into five lithofacies associations (Associations A–E). Each association, comprising one or more lithofacies, represents a specific depositional environment, and marks an independent episode of sedimentation. A dominantly muddy sequence of Facies Association A, a product of a lacustrine environment, is followed by coarsening upward cycles (Association B) composed of silt to sand that implies laterally shifting deltas. Thereafter, thick sand and gravel deposits constituting fining upward (FU) unit cycles (Associations C and D) represent deposition in a fluvial domain. The upper part of Association D, composed of matrix-supported gravel horizons, was deposited as debris flows and marks the termination of sedimentation in the valley. The clastic lithofacies (Facies Associations A to D) with plant fragments and charcoal presumably indicate warm–humid climatic conditions. In contrast, Association E, comprising marl lithofacies occurring at four different levels is biogenic and indicates arid to semi-arid climatic phases. Five main types of trace fossils (including rhizoliths) seem to be representatives of Scoyenia ichnofacies and animal burrows indicating a thin population of soft-bodied annelid and arthropod communities living under low energy condition. Nine fossiliferous horizons have yielded characteristic ostracods, charophytes and gastropods indicating shallow, low energy and cold-water ecological conditions. Coarsening up lake succession, extensive synsedimentary deformation, tilting of lake beds and the entrenchment of the Lamayuru drainage indicate basin evolution under an effective role of neotectonics in the area.

The cretaceous Ladakh arc of NW himalaya—slab melting and melt–mantle interaction during fast northward drift of Indian Plate

The Kohistan–Ladakh Terrane in the NW Himalaya is a remnant of a Cretaceous arc sequence obducted onto the Indian margin. This paper presents a geochemical study (major and trace elements and Sr, Nd, Pb isotopes) of the Mid-Cretaceous lavas of the Ladakh side of the arc sequence, which were erupted in response to northward subduction of Neo-Tethys oceanic crust. Lavas from the western Ladakh in Pakistan can be divided into three groups which, from north to south, are: (1) the Northern Group of back-arc tholeiites [0.5<(La/Yb) N<1.4; 0.3<(Nb/La) N<1.4; 4<εNd<8; 38.66< 208Pb/ 204Pb<38.80], (2) the Southern Group of arc tholeiites [1.8<(La/Yb) N<3.9; 0.1<(Nb/La) N<0.6; 5<εNd<6; 38.40< 208Pb/ 204Pb<38.66], and (3) the Katzarah Formation of tholeiitic Nb-rich lavas [3.4<(La/Yb) N<9.8; 1.4<(Nb/La) N<2.1; 3<εNd<5], including radiogenic Pb lavas [39.31< 208Pb/ 204Pb<39.51] and less radiogenic lavas [38.31< 208Pb/ 204Pb<38.55]. Magmas from the eastern Ladakh in India show a simple series of more evolved arc volcanics from basalts to rhyolites [basalts and basaltic andesites: 2.5<(La/Yb) N<5.7; 0.4<(Nb/La) N<0.5; 1.8<εNd<5.5; 38.70< 208Pb/ 204Pb<38.80]. Isotope and trace element data of western Ladakh lavas are compatible with high-degree melting (14–21%) of a fertile MORB-mantle source. An adakitic lava [(La/Yb) N=55.8; (Nb/La) N=0.3; εNd=1.7; 208Pb/ 204Pb=39.00] and a Mg-poor Nb-rich basalt [(La/Yb) N=4.6; (Nb/La) N=1.3; εNd=−2; 208Pb/ 204Pb=39.07] are spatially associated with the tholeiitic arc lavas. Isotope compositions of all the lavas, and in particular the radiogenic Nb-rich and adakitic lavas suggest three-component mixing between depleted mantle similar to the Indian MORB mantle, and enriched components similar to the volcanogenic or pelagic sediments. The geochemical diversity of magma types is attributed to contribution of melts from the subducted crust and associated sediments, and their subsequent interaction with the mantle. Such melt–mantle interactions can also be inferred from relicts of sub-arc mantle found in Indian Ladakh. These results lead to a geodynamic reconstruction of the Kohistan–Ladakh arc as a single entity in the Mid-Cretaceous, emplaced south of the Asian margin. Slab melting imply subduction of young oceanic crust, as already proposed for the Oman ophiolite farther west. The fast northward drift of the Indian Plate could have triggered wide-scale inversion of the divergent tectonic regime responsible for the opening of the Neo-Tethys Ocean. Our results suggest breaking of the young oceanic crust initiated at the ridge rather than at passive plate boundaries.

Formation of mélanges in the Indus Suture Zone, Ladakh Himalaya by successive subduction-related, collisional and post-collisional processes during Late Mesozoic-Late Tertiary time

Abstract The classic Indus Suture Zone in western Ladakh includes two zones (southern and northern) of highly dismembered rocks, that in the past were widely interpreted as ophiolitic mélanges, created mainly by subduction/accretion processes. The ‘ophiolitic mélange’ was reported to include chaotically distributed blocks of ophiolitic rocks (e.g. serpentinite, gabbro, basalt) and sedimentary rocks (chert, limestone) set in a matrix of deep-sea clastic sediments. This accretionary hypothesis is tested in this paper and found to be inadequate. Units formed simply by oceanic subduction-accretion (i.e. local mud-matrix mélange) are minimal (&lt;1% by volume). In reality, the southern and northern mélange zones are the end products of complex multi-stage tectonic processes, involving subduction (mid-Late Cretaceous to Early Tertiary), initial emplacement (latest Cretaceous), collision (Palaeocene-Eocene) and post-collisional (Late Tertiary) stages. Important components of the mélange as a whole include thrust sheets and broken formation of relatively coherent volcanic-sedimentary successions related to the North Indian passive margin (Karamba and Lamayuru complexes), also mid-Late Cretaceous oceanic arc-type volcanics and volcaniclastic sediments (Dras arc complex). Dismembered serpentinite thrust sheets, cut by swarms of (subduction influenced) diabase dykes, most likely record detached oceanic basement related to the oceanic Dras arc complex. Associated serpentinite was injected along tectonic contacts and into adjacent units during collisional and post-collisional deformation, locally forming serpentinite mélange. Post-collisional, Early-mid-Tertiary non-marine coarse clastic sediments (Indus Group) unconformably overlie various units (serpentinite, volcaniclastics, blueschists) in different locations, and were later thrusted and folded within the southern and northern mélange zones in response to regional Late Tertiary tightening of the suture. As a result, backthrusting reversed the original thrust stacking order, placing the originally most southerly units at the highest structural level. The Indus Suture Zone ‘ophiolitic mélanges’ in western Ladakh are, thus, mainly not ophiolitic (i.e. dismembered oceanic crust), or mélange in entirety (i.e. chaotic block), but are instead dominated by disrupted thrust sheets and broken formation of the Mesozoic Lamayuru-Karamba continental margin and the Upper Cretaceous oceanic Dras arc complex, with only minor preserved remnants of units formed by subduction/accretion (e.g. mud-matrix mélange; oceanic exotics). The southern and northern mélange zones reflect the existence of several N-dipping subduction zones active in latest Cretaceous-Palaeogene times. Although only minor volumes of accreted oceanic material (oceanic lithosphere and trench-type sediments) are preserved within the Indus Suture Zone in western Ladakh, additional accreted material was bulldozed further south onto the Zanskar continental shelf and is now preserved as mélanges beneath the Spontang ophiolite. Similar mélange is also preserved in eastern Ladakh. Subduction zones evolved into a major interconnected shear zone (suture) during Early Tertiary (54–50 Ma) collisional deformation, dismembering upper (oceanic arc) and lower plate (continental margin) units to produce most of the southern and northern mélange zones. After suturing and initial deposition of non-marine coarse clastic cover sediments, inherited weakness zones within the Indus Suture Zone were exploited, increasing disruption during Late Tertiary regional backthrusting. The methods used here in the analysis of the Indus Suture Zone mélange could well prove to be useful elsewhere in the Himalaya and in other orogenic belts. This work also emphasizes the need to distinguish between true mélange v. thrust sheets and broken formation in the field, and also cautions against use of the term ophiolitic mélange unless all the components of a dismembered ophiolite are actually present together.

Phu mkhar rdzong, un lieu de pèlerinage au Ladakh

Abstract Phu mkhar rdzong, a pilgrimage site in Ladakh This paper describes the pilgrimage of Phu mkhar rdzong, a sacred place "opened" by Padmasambhava and still venerated by Buddhists, but situated in Purig (Western Ladakh), a region inhabited mostly by Ladakhi Muslims. The description of the place given in "the new explanation of the holy site" (gnas bshadgso ma), written in 1993 by rTogs Jdan Rin po che, the head of the 'Bri gung pa school in Ladakh who had a long career in Ladakhi politics, is compared with the discourse and behaviour of lay pilgrims. On the basis of this study, the author questions the revitalisation of the pilgrimage and, more generally, the awakening of "national" consciousness among Ladakhi Buddhists along religious / communal lines.

Mesozoic deep-water slope/rise sedimentation and volcanism along the North-Indian passive margin: evidence from the Karamba Complex, Indus suture zone (Western Ladakh Himalaya)

Mesozoic deep-water sedimentary and basic volcanogenic rocks, defined as the Karamba Complex, are exposed within the Indus suture zone of Western Ladakh (N India). The Karamba Complex originated as part of the North-Indian passive margin in its entirety, and does not include exotic melange or accreted oceanic units, as recently suggested. The complex preserves younger, more distal equivalents relative to more proximal deep-water slope (Lamayuru Complex) and shelf (Zanskar) successions of the North-Indian passive margin. The Karamba Complex is mainly inverted, youngs to the NNW, and includes many outcrop-scale folds that face NNW. The Complex was initially emplaced onto the Zanskar Shelf as three main thrust slices probably in the latest Cretaceous, and later inverted, faulted and sheared during mid–late Tertiary NW backthrusting that accompanied uplift of the High Himalaya. Sedimentation in the Karamba Complex began in the Mid–Late Triassic, with mainly siliciclastic turbidites derived from the Indian basement, together with redeposited limestones and minor basic volcanics. Mixed radiolarian sediments, siliciclastic turbidites and redeposited shelf-derived calciturbidites accumulated in Early–Mid Jurassic, accompanied by eruption of alkaline volcanic rocks, mainly in the Mid Jurassic. The probable cause of the Jurassic volcanism was a pulse of crustal extension along the continent–ocean transition zone, triggered by late-stage rifting of India from Gondwana, as a precursor to its northward drift. Quartzose sandstone turbidites accumulated on the upper slope in the Early Cretaceous, whereas sedimentation on the lower slope/rise was pelagic, marked by depositional hiatuses and sediment redeposition. During the Late Cretaceous a switch to mainly calcareous pelagic deposition took place, interspersed with radiolarian accumulation on the lower slope/rise. Initial thrust emplacement onto the Zanskar Shelf in the latest Cretaceous is suggested by the absence of post-Upper Cretaceous sediments within the Karamba Complex.

High-P metamorphic rocks from the Himalaya and their tectonic implication — a review

The suture zones bordering the Indian subcontinent on the E, N and W are characterized in several places by the occurrence of ophiolitic complexes and tectonic melanges. High-P metamorphic rocks have recently been discovered in the melanges in Burma, Naga Hills, southern Tibet, eastern and western Ladakh, Kohistan (Jijal, Allai, Shangla) and Khost (Afghanistan). The development of these rocks has an important bearing on the plate tectonics of the Himalaya. The High-P metamorphic rocks belong to prehnite-pumpellyite, blueschist and high-P greenschist facies but extensive garnet-granulites have developed at 35 km depth in Jijal. In the Indus-Zangbo suture zone (IZS) the high-P metamorphism is complemented to the N by low- or medium-P metamorphism and calc-alkaline magmatism in Tibet, Ladakh as well as Kohistan. High-P metamorphism in Jijal has been dated at 104 Ma, in Shangla at 70–100 Ma and in western Ladakh during mid-Cretaceous. Elsewhere, the timing of the high-P metamorphism is not known but a Cretaceous age is inferred. Since collision along the IZS occurred during Eocene, the high-P metamorphism is therefore related to the northwards subduction of the neo-Tethyan lithosphere under Tibet or late Mesozoic magmatic arcs. The timing of high-P metamorphism coincides with the breakup of India from Gondwanaland and its rapid northwards movement, whereas the tectonic melanges may principally have formed during Eocene collision and obduction.