Invasive Common Reed (Phragmites australis (Cav.) Trin. ex Steud.): A Serious Ecological Threat to Ladakh Tethys Himalayan Biodiversity in Changing Climate

Ladakh’s cropped and non-cropped areas suffer greatly from weedy invasion under subsistence agricultural system where weeding is not a priority but total crop + weed biomass together contribute to livestock feeding significantly. As agriculture along with livestock rearing is major activity of livelihood options, thereby contributing significantly to Ladakh economy and income generation for supporting resource poor farmers. Amongst various invasive weed species, the common reed (Phragmites australis) has become a serious ecological threat for agri-silvi-pastoral system biodiversity and accelerated its expansion in cropped lands including many wetland and salt-affected habitats of cold arid region due to its intermediate plant growth habit of C3 - C4 photosynthetic ecotypes. This character makes Phragmites a climate-resilient species, which is a major challenge for cold arid agriculture in the changing climatic patterns. Simultaneously, it is one of the best fodder substitute available under harsh climate. This paper deals with its unique characters and potential threats to the agrobiodiversity of Ladakh.

The Complex Phenomenon of Glaciers of Nubra Valley, Karakorum (Ladakh), India

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.

PALAEOSHORELINES AS INDICATOR OF LATE CENOZOIC CLIMO-TECTONIC CHANGES IN LADAKH TRANS HIMALAYA:AN ILLUSTRATION FROM TSO KAR LAKE

Compression movements generated by continental collision apart from leading to uplift of the intervening ocean sediments brings about closure of the oceanic body in a phased manner.In the culminating phase of uplift when ocean sediments assume the form of a gigantic mountain system, a number of depressions or closed basins of various dimensions are developed in the orogenic belt. These depressions are principally developed by the differential folding of rocks coupled with faulting and thrusting associated with the uplift process.The mountain drainage gets impounded in these depressions and gives rise to the formation of lakes..During cold climate the depressions are also developed by glacial abrasion wh ich are subsequently filled by snowmelt to form the lakes of various dimensions.Himalaya is dotted with a number of lakes of both tectonic and glacial origin and signify the crown stage of tectonic development of the World’s tallest and youngest mountain belt.A number of lake basins have developed in the various longitudinal belts of this mountain system. Several lake basins like Tso Morari, Pangong Tso and Tso Kar have developed in close proximity of the Indus Suture zone (ISZ),the tectonic belt which marks the zone of continental collision between India and Asia.These lakes by virtue of their location, size, sediment content, water chemistry and associated geomorphic features are the potential source of information in regard to climo\|tectonic changes witnessed by Himalaya\|Tibet region in late Cenozoic period. The paper attempts at elucidating these changes that have occurred in Ladakh Trans Himalaya citing the illustration of the Tso Kar lake.

Geochemistry of eclogites of the Tso Morari complex, Ladakh, NW Himalayas:Insights into trace element behavior during subduction and exhumation

Whole rock major and trace element compositions of seven eclogites from the Tso Morari ultra-high pressure(UHP) complex, Ladakh were determined with the aim of constraining the protolith origins of the subducted crust. The eclogites have major element compositions corresponding to sub-alkaline basalts. Trace element characteristics of the samples show enrichment in LILE's over HFSEs(Rb, Th, K except Ba) with LREE enrichments((La/Lu)n = 1.28-5.96). Absence of Eu anomaly on the Primitive Mantle normalized diagram suggests the absence of plagioclase fractionation. Positive correlation between Mg# with Ni and Cr suggests olivine fractionation of mantle melts. Narrow range of(La/Yb)n(2.1-9.4) and Ce/Yb(6.2-16.2) along with Ti/Y(435-735) ratios calculated for the Tso Morari samples is consistent with generation of melts by partial melting of a garnet free mantle source within the spinel peridotite field. Ternary diagrams(viz. Ti-Zr-Y and Nb-Zr-Y) using immobile and incompatible elements show that the samples range from depleted to enriched and span from within plate basalts(WPB)to enriched MORB(E-MORB) indicating that the eclogite protoliths originated from basaltic magmas.Primitive Mantle normalized multi element plots showing significant Th and LREE enrichment marked by negative Nb anomalies are characteristic of continental flood basalts. Positive Pb, negative Nb, high Th/Ta, a narrow range of Nb/La and the observed wide variation for Ti/Y indicate that the Tso Morari samples have undergone some level of crustal contamination. Observed geochemical characteristics of the Tso Morari samples indicate tholeiitic compositions originated from enriched MORB(E-MORB) type magmas which underwent a limited magmatic evolution through the process of fractional crystallization and probably more by crustal contamination. Observed geochemical similarities(viz. Zr, Nb, La/Yb, La/Gd,La/Nb, Th/Ta ratios and REE) between Tso Morari eclogites and the Group I Panjal Traps make the trap basalt the most likely protoliths for the Tso Morari eclogites.

OBSERVATIONS ON THE QUATERNARY GEOLOGY OF THE LADAKH RANGE, NORTHWEST INDIAN HIMALAYA

Ladakh is a critical area in a determination of the nature of Himalayan glaciation as it lies north of the arid area of Zanskar, where the glacial extent was limited through much of the Late Pleistocene, and south of the Karakoram Range which remains the most heavily glaciated area outside the polar areas and was a centre of extensive glaciation during the Pleistocene.This variation in glacial style and extent across the Himalaya may reflect the interplay between monsoon driven south\|westerly air masses from the Indian Ocean and the westerly air masses from the Mediterranean/Black Sea areas. This paper reports on the first detailed geomorphological observations from within the Ladakh Range and demonstrates the former existence of large glaciers with a number of distinct limits to allow a first approximation of the glacial sequence. Samples for OSL age estimates are currently being processed to constrain a chronostratigraphy. No evidence has been observed for glaciation within the main Indus valley, but large (>80m high) moraine ridges indicate the former existence of glaciers entering from the southern tributary valleys of the Ladakh Range, descending to altitudes of c. 3500m.The Nimu glacier diverted the Indus southwards to erode a new valley with the abandonment of its former valley that can be traced westwards. In the tributary valley north of Leh, impressive termino\|lateral moraine ridges appear to lie on top of older weathered smaller moraine ridges, suggesting a more complex glacial sequence than previously reported.

SERPENTINIZATION OF THE MANTLE WEDGE BY FLUIDS DERIVED FROM CONTINENTAL CRUSTAL MATERIAL: EVIDENCE FROM Nd ISOTOPIC SIGNATURES OF SERPENTINITES (TSO MORARI DOME,ELADAKH)

The well preserved eclogitic rocks of the Tso Morari dome in eastern Ladakh, northwest Himalaya, provide information relevant to the exhumation of high pressure/low temperature rocks, and the early stage of the Himalayan orogeny. The Tso Morari unit outcrops south of the Indus suture zone (Fig.1). The eclogitic dome is underlined on its eastern part by the Zildat normal fault where serpentinite lenses and partially hydrated peridotites are abundant. The close association of the high pressure rocks and serpentinites suggests a possible role of serpentinites in the exhumation of ultrahigh\|pressure rocks. To evaluate this possibility, geochemical analyses were carried out on the serpentinites closely associated with the Tso Morari eclogites.

^(40)Ar-^(39)Ar GEOCHRONOLGY OF THE OPHIOLITE OF INDUS SUTURE ZONE,LADAKH,INDIA:IMPLICATION FOR THE TIMING OF INITIATION OF THE COLLISION

The collision between and Indian and Asian plate has not only give rise to some of the highest mountains of the world but also is responsible for the various global phenomena associated with paleoclimate and paleo\|oceanography.Various indirect approaches have been employed in order to constrain the age of initiation of this collision (Beck et al 1995,D.B.Rowley 1996,Dewey 1989).Still it is being quoted anywhere between ca.60 to 40Ma in the literature.The main reason for the poor constraints on the age of the initiation of the collision is unavailability of a direct method to date this.In this paper we present the Ar\|Ar ages of the ophiolites from the Indus Suture,Ladakh and discuss the scope of this approach in constraining the age of the collision more narrowly.1\ Samples and methodology\;Several ophiolitic melange occurrences have been reported belonging to the Indus Suture in the Ladakh sector.These are characterized by the typical oceanic floor assemblages like chert,limestone etc mixed with the peridotites,serpentinites,dolerites,basalts,and pillow lavas (K.K.Sharma 1990).We present here the 40 Ar\| 39 Ar age spectra of two volcanics from the Sumdo Nala section of central Ladakh and one pillow lava from Chiktan,which is about 100km west of the Sumdo Nala.These samples were analysed using Ar\|Ar step heating method following the procedures described by Venketesan et al.1993.

^(40)Ar-^(39)Ar GEOCHRONOLOGY OF THE SUTURE ZONE, LADAKH, INDIA

Introduction\;A suture zone in an orogenic belt marks the paleo\|plate boundaries with its characteristic ocean floor assemblages. In Himalayas, the best and most spectacular example of the continent\|continent collision orogeny, the suture zone can be traced all along the 2500km long mountain chain and marks the boundary between the Indian and Asian plates. Ladakh region of North\|West Himalaya probably presents the best preserved history of pre\|, syn\|, and post\|collision signatures. It has rocks ranging from Precambrian passive margin sediments to the post collision molasses. The suture zone in Ladakh, referred to as the Indus Suture Zone (ISZ), is characterized by the several occurrences of ophiolitic melange. (M.P. Searle et al, 1987) .Apart from these, various linear belts of the volcanic rocks have been found in the Indus Suture Zone, though their inter relationship is not very clear (K.K.Sharma 1990).

GEOBAROMETRIC CONSTRAINTS ON THE DEPTH OF EMPLACEMENT OF GRANITE FROM THE LADAKH BATHOLITH, NORTHWEST HIMALAYA, INDIA

The Ladakh batholith is exposed along the 600km long and 20 to 80km wide NW—SE trending Ladakh range north of the Indus\|Tsangpo Suture Zone. It was emplaced into an unmetamorphosed thick pile of mafic and felsic volcanics, ultramafics and sediments of Upper Cretaceous\|Eocene age (Dras Volcanics, Khardung Volcanics). The granites from the Ladakh batholith within the Leh\|Khardung La and Sakti—Chang La sections (samples collected between altitude of 3600m and 5440m above mean sea level, Fig.1) have been estimated for pressure and temperature of crystallization employing the hornblende geobarometer of Schmidt (1992) and hornblende\|plagioclase geothermometer of Blundy and Holland (1990), with the results of pressure of (250±60)MPa and temperature of (695±22)℃. Therefore, these granites were solidified at a depth of (8 6±2)km suggesting an unroofing of this thickness in this region. The importance of this geobarometric data in conjunction with age data on the cooling and unroofing history of the Trans\|Himalayan Ladakh batholith and geodynamic implications of the India—Asia collision are discussed.

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^(143)Nd/^(144)Nd ratios(i.e.,0.512908-0.513078 and 0.512901-0.512977,respectively)and positiveε_(Nd)(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.

Geodynamic evolution of the Tethyan lithosphere as recorded in the Spontang Ophiolite,South Ladakh ophiolites(NW Himalaya,India)

The Spontang Ophiolite complex represents the most complete ophiolite sequence amongst the South Ladakh ophiolites and comprises mantle rocks(depleted harzburgites,dunites and minor lherzolites)as well as crustal rocks(basalt,isotropic gabbros,layered gabbros etc.).In the present study,detailed geochemistry(whole rock as well as mineral chemistry)and Sr-Nd isotopic analyses of thirty-six ultramaficmafic samples have been attempted to constraint the evolution and petrogenetic history of the Tethyan oceanic crust.Major,trace-element and REE patterns of the peridotites and their minerals indicate that the lherzolites experienced lower degrees of partial melting resembling abyssal peridotites(at higher temperatures,TREE=$1216℃)than the harzburgites(6%–8%versus 15%–17%).Elevated eNd(t)and variable^(87) Sr/^(86) Sr(t)ratios along with REE patterns suggest that the Spontang mafic rocks display N-MORB affinity with negligible participation of oceanic sediments in their genesis are originated from a depleted upper mantle with little contribution from subduction-related fluids.MORB-type Neotethyan oceanic crust is associated with the earliest phase of subduction(of older Jurassic age)through which a younger intra-oceanic island arc(Spong arc)subsequently developed.Harzburgites REE display typical U-shaped patterns,suggesting that these rocks have been metasomatized by LREE-enriched fluids.On the other side,mafic rocks are characterized by heterogeneous(Nb/La)PMand(Hf/Sm)PMand relatively homogeneous eNd(t),indicating interaction of subduction-related melts with the upper mantle during the initiation of subduction,in Early Cretaceous times.

The occurrence of keratinophilic fungi in selected soils of Ladakh (India)

138 soil samples were collected from various loca-tions in Ladakh, a cold desert in the Himalayan region, India and the samples were screened for the presence of keratinophilic fungi using the hair baiting techniques. 58 isolates were recovered and identified. The cultures were identified based on their macro- and micro-morphological features. A total of six genera and fourteen species were isolated namely Amauroascus kuehnii (0.72%), Aphanoascus keratinophilus (4.34%), Aphanoascus terreus (2.17%), Auxarthron alboluteum (0.72%), Auxarthron conjugatum (0.72%), Chrysosporium articulatum (0.72%), Chrysosporium mephiticum (0.72%), Chrysosporium minutisporosum (2.17%), Chrysosporium siglerae (0.72%), Chrysosporium sp. (1.44%), Chrysosporium tropicum (15.94 %), Chrysosporium submersum (3.62%), Chrysosporium state of Ctenomyces serratus (6.52%) and Geomyces pannorum (1.45%). The present study shows that keratinophilic fungi exist in the cold desert of Ladakh.

Two more bird’s nest fungi from cold desert of Ladakh,India

Two taxa of Agaricaceae viz.,Cyathus colensoi and Cyathus renweii collected from Leh district of Ladakh were described and illustrated.Of these,C.renweii is a new report to India and C.colensoi is being reported for the first time from Jammu and Kashmir.

印度Ladakh地区沙棘叶、果实、种子蛋白含量与叶内硝基酶活性间的关系

沙棘是一种非豆科固氮植物。其蛋白的定性定量评价显示，除了海拔2530～3350m间的种类M-8以外，具有结节的植物普遍比没有结节的植物具有更高的蛋白质含量。在17个沙棘种类的叶、果实、种子中蛋白质水平随着海拔高度的变化在9．65到21．07mg／g鲜重之间变化。其中种子为1．62～5．11mg／g，果实中为0．68～3．51mg／g。数据显示，叶中硝基还原酶活性与蛋白含量存在正相关关系。在海拔较低的Ladakh地区（2500-2850m）发现的种类（M-2，8，13）比海拔高于2850m的种类具有更高的蛋白质含量（12．38-15．10mg／g鲜重），此外，在河畔生长的品种比丘陵斜坡上生长的种类蛋白含量更高。这暗示在荒芜的Ladakh地区，这种沙棘叶可能为人或动物提供多样的食物供给。可以鼓励农业或商业种植沙棘用于饲料。

Glacier Fluctuations between 1975 and 2008 in the Greater Himalaya Range of Zanskar,Southern Ladakh

Glaciers in the Himalaya are often heavily covered with supraglacial debris,making them difficult to study with remotely-sensed imagery alone.Various methods such as band ratios can be used effectively to map clean-ice glaciers;however,a thicker layer of debris often makes it impossible to distinguish between supraglacial debris and the surrounding terrain.Previously,a morphometric mapping approach employing an ASTER-derived digital elevation model has been used to map glaciers in the Khumbu Himal and the Tien Shan.This study on glaciers in the Greater Himalaya Range in Zanskar,southern Ladakh,aims (i) to use the morphometric approach to map large debris-covered glaciers;and (ii) to use Landsat and ASTER data and GPS and field measurements to document glacier change over the past four decades.Field work was carried out in the summers of 2008.For clean ice,band ratios from the ASTER dataset were used to distinguish glacial features.For debris-covered glaciers,topographic features such as slope were combined with thermal imagery and supervised classifiers to map glacial margins.The method is promising for large glaciers,although problems occurred in the distal and lateral parts and in the fore field of the glaciers.A multi-temporal analysis of glaciers in Zanskar showed that in general they have receded since at least the mid-to late-1970s.However,some few glaciers that advanced or oscillated - probably because of specific local environmental conditions - do exist.

论拉达克国王策旺纳木扎勒与清廷的关系——以乾隆朝满文档案《叶尔羌办事大臣期成额等奏图伯特伯克策旺纳木扎勒遣使呈报爱乌罕屯兵事宜折》为中心

本文通过乾隆朝满文档案《叶尔羌办事大臣期成额等奏图伯特伯克策旺纳木扎勒遣使呈报爱乌罕屯兵事宜折》为中心,结合现有藏学研究成果,首先对拉达克王国地域界定进行简要阐述;其次考述策旺纳木扎勒的身份;再次对满文文献内记载的有关策旺纳木扎勒通过叶尔羌办事大臣处与清廷的互动进行梳理,并对一些人名、地名等进行考证;最后论证总结乾隆朝清廷在处理与拉达克国王及王国关系问题上的基本准则。笔者认为,通过以乾隆朝满文档案为基础,挖掘、分析、论证文献内记载的珍贵历史线索,研究乾隆朝拉达克王国与清廷的关系,对于今天我国在处理与周边国家和地区,尤其是涉及与中亚、南亚关系等方面,仍具有重要的历史价值和战略意义。

8—12世纪拉达克地区的石刻造像及其历史意蕴

针对拉达克地区8—12世纪的一批佛教石刻造像,在系统整理造像遗存的基础上,结合造像题记、地理位置及历史文献,对石刻造像的赞助人、造像题材、开凿意图、造像功能及其背后所呈现的阿里三围对吐蕃王朝遗产的承续关系进行讨论。拉达克地区石刻造像是在藏族人主导下所建的,其时间从吐蕃王朝中后期持续到阿里三围初期,石刻造像传统的延续反映出两代不同政权之间的文化接续;吐蕃王朝时期石刻造像题材以大日如来佛为主,阿里三围初期石刻造像则更流行菩萨题材,石刻造像题材的转变与政权更迭后的宗教政策有关;造像题记所载人物皆为王公贵族,造像所处地理位置与文献记载的政治军事活动相契合,展现出石刻造像始终承载的军政象征等多重历史意涵。

巴基斯坦西北喜马拉雅构造结科希斯坦—拉达克地体Pb同位素组成特征及其示踪意义

作为西北喜马拉雅构造结的重要组成部分,科希斯坦-拉达克地体的Pb同位素组成具有混合Pb的特征。笔者在前人研究的基础上重新分析了Pb同位素组成特征,并计算了H-H单阶段演化模式年龄,以及μ、ω、Th/U、Δβ、Δγ值等重要参数。分析表明,Pb主要来源于壳幔混合物质,但也混入了部分亚洲大陆地壳物质,其类型相当于受岩浆控制的俯冲带Pb同位素组成。通过研究,发现Pb同位素比值具有DUPAL异常特征,推测异常Pb可能来源于亚洲大陆边缘,这可作为研究本区岩浆作用及演化的重要基础资料。

20世纪上半叶拉达克口岸的藏盐贸易

藏盐贸易是历史上拉达克地区与我国西藏西部阿里、藏北羌塘一带重要的传统贸易内容。本文主要依据来自英国印度事务部的贸易档案资料,对20世纪上半叶处在英属印度控制下的拉达克与我国西藏之间的食盐交易情况进行了细致的探析,揭示出这一贸易过程呈现的主要特点以及影响贸易开展的主要因素,表明在该贸易背后两地人民间深层次的经贸与文化生活联系。

拉达克藏传佛教寺院建筑地域性艺术特征研究

拉达克地区历史上属于藏传佛教文化圈,其境内现存的藏传佛教建筑有藏式宫殿、寺院和簌堵坡等。除了鲜明的藏传佛教建筑特征,拉达克藏传佛教建筑艺术因为受印度文化和中亚文化的双重影响,显示出一定的国际化特征。其寺院平面布局、建筑装饰以及塑像和壁画,对世界建筑史和艺术史研究都有重要意义。本文试图通过对拉达克藏传佛教寺院建筑与装饰的中亚元素、印度元素与西藏元素的比较,从建筑史和文化史角度说明拉达克藏传佛教寺院的地域性特征。