quaternary glaciation of the himalayan tibetan orogen glacial geological evidence from throughout the himalayan tibetan orogen is examined to determine the timing and extent of late quaternary glaciation in this region and its relation to similar changes on a global scale the evidence summarised here supports the existence of expanded ice caps and extensive valley glacier systems throughout the region during the late quaternary however it cannot yet be determined whether the timing of the extent of maximum glaciation was synchronous throughout the entire region or whether the response was more varied the lack of organic material needed for radiocarbon dating has hindered past progress in glacial reconstruction however application of optically stimulated luminescence and terrestrial cosmogenic radionuclide methods has recently expanded the number of chronologies throughout the region limits to the precision and accuracy available with these methods and more importantly geological uncertainty imposed by processes of moraine formation and alteration both conspire to limit the time resolution on which correlations can be made to milankovitch timescales several ka in order to put all studies on a common scale well dated sites have been re evaluated and all the published terrestrial cosmogenic nuclide ages for moraine boulders and glacially eroded surfaces in the himalayan tibetan orogen have been recalculated locally detailed studies indicate that there are considerable variations in the extent of glaciation from one region to the next during a glaciation glaciers throughout monsoon influenced tibet the himalaya and the transhimalaya are likely synchronous both with climate change resulting from oscillations in the south asian monsoon and with northern hemisphere cooling cycles in contrast glaciers in pamir in the far western regions of the himalayan tibet orogen advanced asynchronously relative to the other regions that are monsoon influenced regions and appear to be mainly in phase with the northern hemisphere cooling cycles broad patterns of local and regional variability based on equilibrium line altitudes have yet to be fully assessed but have the potential to help define changes in climatic gradients over time copyright 2008 john wiley sons ltd

quaternary glaciation of the tashkurgan valley southeast pamir the quaternary glacial history of tashkurgan valley in the transition between the pamir and karakoram in xinjiang province china was examined using remote sensing field mapping geomorphic analysis of landforms and sediments and 10be terrestrial cosmogenic nuclide dating moraines were assigned to four glacial stages 1 the dabudaer glacial stage that dates to the penultimate glacial cycle and or earlier and may represent one or more glaciations 2 the tashkurgan glacial stage that dates to early last glacial most likely marine oxygen isotope stage mis 4 3 the hangdi glacial stage that dates to mis 2 possibly early mis 2 and 4 the kuzigun glacial stage that dates to the mis 2 possibly the global last glacial maximum and is younger than the hangdi glacial stage younger moraines and rock glaciers are present at the heads of tributary valleys but these were inaccessible because they are located close to politically sensitive borders with pakistan afghanistan and tajikistan glaciers during the dabudaer glacial stage advanced into the central part of the tashkurgan valley during the tashkurgan glacial stages glaciers advanced several kilometers beyond the mouths of the tributary valleys into the tashkurgan valley glaciers during the hangdi and kuzigun glacial stages advanced just beyond the mouths of the tributary valleys glaciation in this part of the himalayan tibetan orogen is likely strongly controlled by northern hemisphere climate oscillations although a monsoonal influence on glaciation cannot be ruled out entirely

quaternary glaciations and glacial landform evolution in the tailan river valley tianshan range china abstract the tailan river originates on the southern slope of tumur peak the largest center of modern glaciation in the tianshan range five moraine complexes and associated fluvioglacial deposits in this valley record a complex history of quaternary glacial cycles and landform evolution electron spin resonance esr dating of glacial sediments was carried out using germanium ge centers in quartz grains which are sensitive to both sunlight and grinding based on the dating results as well as geomorphic and stratigraphic data the piyazilike end moraines the second moraine complex were deposited during neoglaciation the largest glacial advances during the last 3 4 ka in western china and an early holocene glacial advance the third set of moraines was deposited in marine isotope stage mis 2 4 and the glacial landforms of the tailan glaciation the fourth moraine complex which include hummocky moraines on the piedmont were formed in mis 6 penultimate glaciation the end moraines of the innermost moraine complex the first moraine complex are inferred to have been deposited during the little ice age lia thus the landforms and dates indicate compound valley glaciers from the lia to mis 2 4 and piedmont glaciers during mis 6 the oldest tills studied belong to the kokdepsang glacial stage and occur on a high plateau based on similar glacial landforms glacial deposits on a high plateau and a high glacial terrace and their esr ages in adjacent valleys on the southern slope of tumur peak the kokdepsang glacial stage is assigned to mis 12

reconstruction of the 2 4 million km2 late pleistocene ice sheet on the tibetan plateau and its impact on the global climate during 20 expeditions new data were obtained on the maximum extent of glaciation in tibet and the surrounding mountains evidence was found of moraines at altitudes as low as 460 m on the southern flank of the himalayas and 2300 m on the northern slope of the tibetan plateau in the qilian shan on the northern slopes of the karakorum aghil and kuen lun moraines occurred as far down as 1900 m in southern tibet radiographic analyses of erratics document former ice thicknesses of at least 1200 m glacial polishing and knobs in the himalayas and karakorum are proof of glaciers as thick as 1200 2000 m on the basis of this evidence a 1100 1600 m lower equilibrium ela line was reconstructed for the ice age which would mean 2 2 4 million km2 of ice covering almost all of tibet since the equilibrium ela line was far below the average altitude of tibet on mount everest and k2 radiation was measured up to 6650 m yielding values of 1200 1300 w m2 because of the subtropical latitude and the high altitude solar radiation in tibet is 3 4 times greater than the energy intercepted between 60 and 70 n or s with an area of 2 2 4 million km2 and an albedo of 90 the tibetan ice sheet caused the same heat loss on the earth as a 6 9 6 million km2 sized ice sheet at 60 70 n because of its proximity to the present day equilibrium ela line tibet must have undergone large scale glaciation earlier than other areas being subject to intensive radiation the tibetan ice must have performed an amplifying function during the onset of the ice age

extent and spatial distribution of pleistocene glaciations in eastern tibet as a contribution to the controversial discussion regarding the nature and extent of the pleistocene glaciation on the tibetan plateau additional observations and results were obtained during several chinese german joint expeditions in the investigation area of the eastern and central tibetan plateau it will be shown that the maximum extent of the last glaciation was limited to the glaciation of isolated mountain groups or smaller plateau glaciations these glaciations are characterized by glacial erosional features such as u shaped valleys in the inner mountain massifs and cirques in the higher summit areas accumulation forms such as terminal and lateral moraines less common than basal moraines are marked by granitic and basaltic erratics using two examples from the eastern margin of the tibetan plateau nianbaoyeze shan and northern chola shan the extent of pleistocene glaciations can be mapped by the distribution of terminal and lateral moraines and erratic granite boulders on the slopes of the surrounding schists two to three main pleistocene glaciations can be separated using weathering criteria paleosols and the overlying stratum on the moraines and associated terrace sequences overlying stratum consist of aeolian sandy silt or solifluction debris the younger moraines are found to be characterized by large erratics were therefore named big boulder moraine and can be found over the investigated area the ice free areas are characterized by pleistocene terraces along the main rivers loess deposits with sand and ice wedges at higher elevations e g the basin of zoige and paleosols in the basins below 3500 m a s l e g aba basin or garze basin the hypothesis of an extensive plateau glaciation could not be verified for this region a rising snowline equilibrium line altitudes elas is revealed in two cross sections during the last glacial maximum lgm at the eastern and northern margin of the tibetan plateau snowlines migrated from about 4000 m in the east minshan to 4300 m in the nianbaoyeze and to about 4700 m in the west bayan har shan a rise was also recorded from about 3800 m in the north central qilian shan up to a range of 4300 4950 m different exposures in the kunlun shan to approximately 5200 m in the tanggula shan in the center of the tibetan plateau the general increase of modern and lgm snowlines or elas towards the plateau corresponds with a decrease of precipitation from east to west and from north to south respectively precipitation was more pronounced at the eastern margin during glacial times than compared to present

timing and style of late quaternary glaciation in northeastern tibet glacial successions in the anyemaqen and nianbaoyeze mountains of northeastern tibet are reassessed and new glacial chronologies are presented for these regions cosmogenic radionuclide and optically stimulated luminescence dating indicates that two glacial advances occurred in marine isotope stage mis 3 and mis 2 in the anyemaqen mountains a third advance occurred in the early holocene we suggest that glaciation was synchronous in the anyemaqen and nianbaoyeze mountains as well as in other glaciated areas of tibet and the himalaya that are influenced by the asian monsoon the maximum extent of glaciation occurred early in the last glacial cycle mis 3 during a time of increased insolation when the monsoon intensified and supplied abundant precipitation as snow at high altitude to feed high altitude glaciers this suggests that precipitation as snow is fundamental in controlling glaciation in these regions however the occurrence of glacial advances during the insolation minimum of mis 2 suggests that despite reduced precipitation at this time the annual temperatures were cold enough to maintain positive glacier mass balances the numerically defined chronologies for the anyemaqen and nianbaoyeze mountains presented here provide a framework for comparing glacial advances in other parts of high asia

on the problem of quaternary glaciations and the extent and patterns of pleistocene ice cover in the qinghai xizang tibet plateau abstract data accumulated during investigations since the 1960s indicate that up to four pleistocene glaciations can be recognized in the qinghai xizang tibet plateau and the adjacent himalaya mountains in order of decreasing age these are the xixabangma nyanyaxungla guxiang and baiyu glacial episodes the history of pleistocene glacial evolution in various areas throughout the plateau differs and the pattern is very complex throughout the early pleistocene the elevation of the qinghai xizang plateau was approximately 2000 m above sea level during the xixabangma glacial episode recorded at higher elevations the climate and topographical conditions on the plateau were largely unfavourable for the development of glaciers present investigations have revealed that the oldest till is only found at isolated localities on the plateau glaciofluvial or alluvial deposits such as the gongba conglomerate dating from 2 4 to 0 73 ma bp and the fluvial lacustrine deposits of the qiantang group dating from 2 4 to 1 7 ma bp are present rather than glacial till therefore the postulate of a large early pleistocene ice sheet proposed previously has been disproves during the most recent glaciation uplift of the plateau and the himalayas continued the majority of the qinghai xizang plateau reached 4000 m a s l and the great himalaya were approximately 6000 m a s l the mountains formed a barrier against the incursion of the indian monsoon so that precipitation decreased sharply on the northern flank of the himalayas and the climate to the north became cold and dry all of the glaciers on the qinghai xizang plateau underwent extensive retreat thus during the pleistocene no unified glacial cover existed over the qinghai xizang plateau similarly the source area of the hwang he yellow river did not support a local ice sheet

far flung moraines exploring the feedback of glacial erosion on the evolution of glacier length abstract over many glacial cycles the glacial erosion of alpine valleys can be sufficient to reduce the length of glaciers in the most recent cycles we document field cases illustrative of this erosional feedback and model the long term evolution of glacier lengths analytically and numerically the general feature we target is a moraine deposited well beyond the last glacial maximum lgm limit which we refer to as a far flung moraine firstly we assemble published observations to illustrate that far flung moraines are documented around the world the observations suggest that the downvalley distance to such far flung moraines can exceed the distance to lgm moraines by up to twofold secondly we address the problem analytically making several simplifying assumptions to demonstrate that glacier length scales linearly with erosion depth finally we employ a numerical model to test the analytical solution this 1d depth integrated flowline model includes i a depth averaged longitudinal coupling stress approximation ii prescribed winter and summer surface mass balance profiles iii evolving ice temperature calculated via the conventional heat equation and iv glacier sliding velocity parameterized as a function of basal ice temperature and spatially and temporally variable prescribed flotation fraction the simulated alpine landscape is modified through the competing processes of glacier erosion which is dependent on glacier sliding velocity and prescribed bedrock erodibility and prescribed uplift rate the climate controlling surface mass balance is prescribed by time series of air temperature and snowfall approximated by the sum of two sinusoidal cycles the recurrence statistics of these prescribed climate drivers closely match those of the marine isotopic record hence the prescribed climate drivers faithfully mimic observed long term climate drivers consistent with earlier landscape evolution studies we find that the primary effect of repeated glaciations is to flatten a valley floor and steepen its headwall effectively cutting a longitudinal notch in a fluvial valley profile analytical and numerical model results also demonstrate that far flung moraines are an inevitable consequence of repeated glaciations glaciers in tectonically inactive regions can sufficiently erode their valleys so that the earliest glaciations leave moraines many kilometers down valley from moraines left by the latest glaciations despite similar climates this suggests that a different landscape rather than a different climate is capable of explaining the early glacier extents as a corollary the long term drift toward reduced glacier length favors the survival of early moraines in the face of later glacial advances finally rock uplift can defeat this erosional feedback while rock subsidence enhances the feedback

quaternary glacial chronology of the kanas river valley altai mountains china the kanas river originates on the southern slope of youyi peak the largest center of modern glaciation in the altai mountains in central asia glaciers advanced and retreated repeatedly during quaternary glacialeinterglacial cycles in the kanas river valley and four moraine complexes and associated glaciofluvial deposits are preserved in the valley optically stimulated luminescence osl dating has been used to determine ages of glaciofluvial deposits sand lenses sandwiched between tills in moraines using a single aliquot regenerative dose sar protocol based on dating results from this and previous studies including 14 c electron spin resonance esr and osl dates and geomorphic relationships the innermost moraine complex was concluded to deposit during the little ice age lia the second akekule moraine complex was deposited during the neoglacial the third kanas moraine complex was deposited during the last glacial cycle marine oxygen isotope stage mis 2e4 and the outermost set of moraines is mis 6 in ages penultimate glaciation the kanas moraine complex could be divided into three subsets iii1 iii2 and iii3 with inferred ages of mis 2 mid mis 3 and mis 4 respectively which is consistent with moraine records from other areas in central asia and climate reconstructions from the guliya ice core the glaciers in the kanas valley at their maximum extents during the lia neoglacial last glaciation and penultimate glaciation were 13 8 km 32 km w100 km and w120 km long respectively

review of the timing and extent of glaciers during the last glacial cycle in the bordering mountains of tibet and in east asia new accelerator mass spectrometry 14c ams14c electron spin resonance esr and thermoluminescence tl dates for glacial successions in tibetan bordering mountains and in east asia show that glacier extent during the early middle mis3 4 parts of the last glacial cycle was larger than that of the late stage mis2 in last glacial cycle glaciation was not synchronous with the north hemisphere ice sheet maxima and changes in oceanic circulation that predominately control global climate there exist three seasonal precipitation patterns that control the accumulation and ablation on glaciers in the study areas areas dominated by westerlies including the east asia coastal islands experience glacier advance mainly because of increased winter precipitation these glaciers expand during glacial stages in contrast in areas dominated by summer precipitation in the interior of mainland except in the monsoonal high precipitation zone in southeast tibet and the hengduan mountain range tend not to develop large glaciers during major glacial stages

summer temperature reconstruction on the central tibetan plateau during 1860 2002 derived from annually resolved ice core pollen 1 we present a 140 year ice core pollen record with annual time resolution from the puruogangri ice field in the central tibetan plateau a linear regression model between the sum of the steppe and meadow pollen taxa and summer temperature at naqu accounts for 66 of the summer temperature variance for the period 1955 2002 on the basis of this model we reconstructed summer temperature history for the central tibetan plateau from 1860 to 2002 three marked warm periods during the 1870s 1890s and 1990s and five cold periods during the 1860s 1880s 1900s 1950s and 1960 1970s were identified within the last 100 years late 20th century warming is distinctive and may have had a major role in the present retreat of most glaciers on the tibetan plateau the pollen record is also significantly correlated with average annual temperatures over the whole tibetan plateau suggesting that these proxy data have the potential for reflecting large scale regional temperature change the statistically significant similarity between the puruogangri ice core pollen record and the 18o time series indicates that both are reliable indicators of temperature change at annual to multiyear timescales in this region

esr dating studies of palaeo debris flow deposits in dongchuan yunnan province china abstract the ages of palaeo debris flow deposits in dongchuan yunnan province were determined by esr dating they are consistent with a 14 c age estimate the results suggest that the debris flow deposits were formed during humid periods of the late pleistocene simulation experiments and sem analysis show that the resetting of ge centres in quartz is most likely due to collisions of the quartz grains during the process of rapid deposition

a review of glacial sequences of the kunlun pass northern tibetan plateau abstract in the kunlun pass area of northern tibet glacial landforms and sediments provide evidence for three major quaternary glaciations esr and tl dating suggest that they date to 600 700 ka wangkun glaciation 260 ka yakou glaciation and 61 13 ka yuzhufeng glaciation the last glacial each glaciation is less extensive than its predecessor the wangkun glaciation is the largest quaternary glaciation the extent of the glaciers during the wangkun glaciation was 3 5 times larger than that of the present glaciers during the last glacial glaciers advanced several times the moraines near the modern glaciers are probably the products of neoglaciation and little ice age

osl dating of glacier extent during the last glacial and the kanas lake basin formation in kanas river valley altai mountains china the kanas river originates on the southern slope of youyi peak the largest center of modern glaciers in altai mountains china three sets of moraines and associated glacial sediments are well preserved near the kanas lake outlet recording a complex history and landscape evolution during the last glacial dating the moraines allows the temporal and spatial glacier shift and climate during the last glacial to be determined and then constrains when and how the kanas lake basin was formed dating of the glacial tills was undertaken by utilizing the optically stimulated luminescence osl method results date four samples from the three sets of moraines to 28 0 34 4 38 1 and 49 9 ka and one sample from outwash sediment to 6 8 ka the kanas lake basin is a downfaulted basin and was eroded by glacier before 28 0 ka and the glacial moraines blocked the glacier melt water after the glacier retreat which made the present day kanas lake eventually form at least before 6 8 ka bp in altai mountains the glacier advance was more extensive in marine isotope stage mis 3 than mis 2 probably because the mid latitude westerlies shifted northward and or intensified during the mis 3 resulting in a more positive glacier mass balance nevertheless the siberian high dominated the altai mountains in mis 2 resulting in a relative decrease in precipitation

climatic and topographic controls on the style and timing of late quaternary glaciation throughout tibet and the himalaya defined by 10be cosmogenic radionuclide surface exposure dating abstract temporal and spatial changes in glacier cover throughout the late quaternary in tibet and the bordering mountains are poorly defined because of the inaccessibility and vastness of the region and the lack of numerical dating to help reconstruct the timing and extent of glaciation throughout tibet and the bordering mountains we use geomorphic mapping and 10 be cosmogenic radionuclide crn surface dating in study areas in southeastern gonga shan southern karola pass and central western nyainqentanggulha shan and tanggula shan tibet and we compare these with recently determined numerical chronologies in other parts of the plateau and its borderlands each of the study regions receives its precipitation mainly during the south asian summer monsoon when it falls as snow at high altitudes gonga shan receives the most precipitation 2000 mm a 1 while near the margins of monsoon influence the karola pass receives moderate amounts of precipitation 500 600 mm a 1 and in the interior of the plateau little precipitation falls on the western nyainqentanggulha shan 300 mm a 1 and the tanggula shan 400 700 mm a 1 the higher precipitation values for the tanggula shan are due to strong orographic effects in each region at least three sets of moraines and associated landforms are preserved providing evidence for multiple glaciations the 10 be crn surface exposure dating shows that the formation of moraines in gonga shan occurred during the early mid holocene neoglacial and little ice age on the karola pass during the lateglacial early holocene and neoglacial in the nyainqentanggulha shan date during the early part of the last glacial cycle global last glacial maximum and lateglacial and on the tanggula shan during the penultimate glacial cycle and the early part of the last glacial cycle the oldest moraine succession in each of these regions varies from the early holocene gonga shan lateglacial karola pass early last glacial western nyainqentanggulha shan and penultimate glacial cycle tanggula shan we believe that the regional patterns and timing of glaciation reflect temporal and spatial variability in the south asian monsoon and in particular in regional precipitation gradients in zones of greater aridity the extent of glaciation has become increasingly restricted throughout the late quaternary leading to the preservation of old 100 ka glacial landforms in contrast in regions that are very strongly influenced by the monsoon 1600 mm a 1 the preservation potential of pre lateglacial moraine successions is generally extremely poor this is possibly because lateglacial and holocene glacial advances may have been more extensive than early glaciations and hence may have destroyed any landform or sedimentary evidence of earlier glaciations furthermore the intense denudation mainly by fluvial and mass movement processes which characterize these wetter environments results in rapid erosion and re sedimentation of glacial and associated landforms which also contributes to their poor preservation potential

quaternary glacial chronology of the ateaoyinake river valley tianshan mountains china abstract the ateaoyinake river originates on the southern slope of the tumur peak the largest center of modern glaciation in the central tianshan mountains in china six sets of moraines and associated glacial sediments are well preserved in the ateaoyinake river drainage recording a complex history of quaternary glacial cycles and landscape evolution dating the landforms allow the temporal and spatial shifts of past cryosphere and climate to be determined dating of the tills and outwashes was undertaken with electron spin resonance esr and optically stimulated luminescence osl two osl ages date outwash and till to 7 3 0 8 ka and 12 3 1 2 ka respectively the esr ages date six sets of moraines to 3 4 ka 14 27 ka 40 54 ka 55 62 ka 134 4 12 6 ka and 219 7 20 5 ka 440 6 41 7 ka if these are correct ages of deposition they suggest that glaciers advanced during the neoglacial and during marine oxygen isotope stages mis 2 3b 4 6 and 12 the mis 3b moraine was created by a glacier nearly as large as or possibly larger than those of the global last glacial maximum of mis 2 the oldest till belongs to the qingshantou glacial stage its single age is consistent with two published esr ages 459 7 46 and 471 1 ka from the gaowangfeng till near the headwaters of the urumqi river in the eastern tianshan mountains these dates suggest that the central and the eastern segments of the tianshan mountains were high enough to be glaciated by mis 12 the geochronology of the glacial landforms in this valley is the first step towards understanding glacial and landscape evolution in this region furthermore this geochronology and previously published geochronology near the headwaters of the urumqi river provide a temporal framework for examining the rates of landscape evolution in the glaciated regions of the tianshan mountains

climate lithology and tectonics interaction in shaping a hazardous salt karst a case from the middle late miocene evaporite succession of ne iran abstract karst landforms cover a considerable area of the earth s surface with increasing population and demand for further land exploitation the prospect of being affected by karsts has increased dramatically over the past decades among karst landforms salt karsts show higher vulnerability and faster evolution in the human life span in iran most of salt karst studies have been carried out in the south mainly zagros contrariwise the northern and central parts of the country have been rarely studied this study investigates a salt karst system in the northeastern part of the central iran field investigation and satellite image analysis of the area revealed a salt karst in the upper red formation urf comprising elements of a mature karstic system including dolines ponors caves shafts valleys poljes springs and streams tectonics by creating open fractures in impermeable salts provided conduits for fluid transport and development of the karst since salts are highly soluble and disappear very soon arid climate in the studied area led to the preservation of the salt karst although the area is a cold desert with small amounts of precipitation it is hydrologically active this is ascribed to the increased water efficiency by the karst system that immediately funnels the runoffs into the ground and prevents from evaporation water efficiency is amplified by an impermeable substrate of the karst and timing of the precipitation the studied karst partly underlies the tehran mashhad railway which endangers the infrastructure and can cause failure and casualties since the salt bearing urf extends throughout large parts of central iran this study suggests comprehensive geomorphological hydrogeological and geophysical studies of this formation for providing hazard maps

landscape analysis of the huang he headwaters ne tibetan plateau patterns of glacial and fluvial erosion the large scale geomorphology of the huang he yellow river headwaters centered around the bayan har shan 5267 m asl in the northeastern part of the tibetan plateau is dominated by an uplifted

influence of climate change on saline lakes of the tibet plateau 1973 2010 abstract levels and surface areas of saline lakes are indicators of climate change and climate variability the surface extents of 93 saline lakes with areas larger than 20 km2 excluding dry saline lakes on the tibet plateau were delineated from landsat images obtained in 1973 1977 1989 1992 1999 2001 and 2008 2010 based on remote sensing spatial analysis techniques and gis the dynamic changes of the saline lake surface areas from 1973 to 2010 were analyzed the total surface area of these saline lakes increased especially since around 2000 and the total surface area increased by 47 during 1973 1977 to 2008 2010 during 1973 1977 to 1989 1992 saline lakes with decreased areas were mainly distributed in the northern and middle parts of the tibet plateau whereas those in other places tended to expand since around 2000 nearly all the saline lakes expanded mean annual temperature mean annual maximum temperature mean annual minimum temperature annual precipitation and evaporation on the tibet plateau were analyzed over the past four decades the climate has become warmer and wetter rising temperature and dropping evaporation are two dominant factors responsible for saline lake expansion the salinity of many saline lakes decreased during this climate warming new analyses included factors responsible for the changes i e tectonics climate lake basin shape glaciers catchments open or closed systems and human activities

the sequence of quaternary glaciation in the bayan har mountains four periods of quaternary glaciation in the pleistocene have been found in the area of the bayan har mountains they represent respectively the two stages of the last glacial age the penultimate ice age and an earlier ice age during the late stage of the last glacial age glaciers developed only near the mountain ridges of the bayan har in the earlier stage glaciers expanded down to the piedmont of the bayan har mountains and were as much as 40 km long in the penultimate ice age an extensive ice cover developed depositing an areally widespread till sheet erratics were transported 60 km from bayan har peak to qingshuihe town to the south and to yematan land to the north granitic erratics are also distributed over elevated geomorphological positions such as chalaping ridge the area of ice cover encompassed up to 50 000 km2 furthermore evidence including glacial landforms and sediments shows that a larger glaciation existed in this area in an earlier time possibly during the third most recent ante penultimate glaciation the scale of this glaciated area is greater than those of the more recent events in the qinghai xizang plateau extending over 80 000 km2 this glaciation covered the source area of the yellow river from xingsuhai in the west to duogerangtan in the east including the areas of gyaring and ngoring lakes based on the extent and locations of the glaciations the bayan har stage and galalahai stage of the last glacial age the yematan ice age and the huanghe glacial age can be recognized

glacier mass loss induced the rapid growth of linggo co on the central tibetan plateau remote sensing and gis techniques in conjunction with field investigations show how glacier mass loss has led to the rapid growth of linggo co a glacier fed lake on the central tibetan plateau which has expanded by 21 3 in area between 1974 and 2010 with a lake level rise of 11 2 m the lake volume of linggo co increased at a rate of 0 02 10 6 42 67 10 6 and 65 8 10 6 m 3 a 1 during the periods 1974 92 1992 99 and 1999 2010 respectively other non glacier fed lakes in the vicinity i e longwei co amur co and darngo co ngion shrank considerably from the early 1970s to 1992 and then expanded from 1992 to 2010 despite being in the same climate region linggo co and the non glacier fed lakes have differed in response to climate change the glaciers in the catchment of linggo co retreated by 2 4 in area between 1974 and 2007 and their mean thickness decreased by 6 19 1 91 m between 1974 and 2000 with an associated glacier meltwater runoff of 7 52 2 32 10 8 m 3 the results indicate that glacier mass loss had a significant impact on the growth of linggo co over the past 40 years

cosmogenic radionuclide evidence for the limited extent of last glacial maximum glaciers in the tanggula shan of the central tibetan plateau abstract cosmogenic radionuclide crn exposure ages provide evidence for the limited extent of last glacial maximum glaciers in the tanggula shan central tibetan plateau the most extensive advances occurred during or before marine oxygen isotope stage 6 mis 6 based on previous crn exposure ages the second most extensive advance occurred during or before mis 4 based on previous ages and new ages of 41 400 4300 and 66 800 7100 10 be yr a mis 2 advance of less than 3 km occurred between 31 900 3400 and 16 000 1700 10 be yr

quaternary glaciation of tibet the geological evidence the question of the number and extent of pleistocene glaciations on the qinghai xizang tibet plateau remains contentious there has been considerable research activity in tibet by chinese scientists since the late 1950s and their principal findings including data on glacial and periglacial geomorphology sedimentology tectonics stratigraphy and lake history have been used to reconstruct ice margins and palaeosnowlines three and in places four distinct glaciations have been recognised the most extensive occurring in the later middle pleistocene valley and piedmont glacial systems with some mountain ice caps and a small ice sheet on the upper reaches of the huang he have been recognised but there is no evidence of a single tibetan ice sheet as the plateau and the himalaya karakoram underwent accelerating uplift through the quaternary there occurred progressive desiccation in the interior as the influx of indian ocean moisture was constrained equilibrium line elevations in the last glacial maximum were 4000 m in the south east and northeast plateau margins rising to 5500 m in the northwest interior the heat island provided by the plateau the progressive reduction in precipitation most marked during the glacials and the strong southeast to northwest precipitation gradients produced a glacier distribution pattern dominated by the trans tibetan mountain ranges tectonics and periglacial including aeolian processes have played an equal role with glaciation in generating the plateau s quaternary sedimentary succession

the u pb ages and hf isotopes of detrital zircons from hainan island south china implications for sediment provenance and the crustal evolution in situ u pb dating and hf isotopic of detrital zircons from beach sediments of yalong bay were analyzed to trace sedimentary provenance and reveal the crustal evolution of hainan island in south china the grain size distribution of the sediments displays a clear single peak feature indicating the sediments were formed under the same condition of hydrodynamic force the detrital zircons had th u ratios of greater than 0 1 and ree pattern displayed a positive ce anomaly and a negative eu anomaly indicating that these zircons are predominantly of magmatic origin the u pb spectrum of detrital zircons mainly peaked at the yanshanian 96 185 ma hercynian indosinian 222 345 ma and caledonian 421 477 ma a portion of the detrital zircons were of neoproterozoic origin 728 1 003 ma which revealed that the basement in the eastern region of hainan island was mainly of neoproterozoic with rare archean materials the positive ehf t values 0 to 10 1 of the neoproterozoic detrital zircons indicated that the juvenile crust grew in the southeastern hainan island mainly during the neoproterozoic period the neoproterozoic orogeny in the southeastern part of the island 0 7 1 0 ga occurred later than in the northwestern region of the island 1 0 1 4 ga importantly the grenvillian orogeny in the southeastern area of hainan island shared the same timing with that of the western cathaysia block i e both areas concurrently underwent this orogenic event thereby forming a part of the rodinia supercontinent afterwards the crust experienced remelting and reworking during the caledonian hercynian indosinianand yanshanian accompanied by the growth of a small amount of juvenile crust

quaternary glaciation of puruogangri the largest modern ice field in tibet abstract the puruogangri the largest modern ice field in the tibetan plateau with an area of over 400 km2 in total is in the inner plateau although it is very difficult to reach the scale of the ice field makes it important to study the quaternary glaciation in this inland area to determine whether there was a unified ice sheet in the tibetan plateau during the quaternary field observation showed that five moraine groups termed moraine i v of terminal moraines and lateral moraines are present located from the snouts of modern glaciers to the piedmont based on geomorphic locations stratigraphic correlation relative weathering reworked degrees by wind action and the esr ages of the sands covering the gobi with erratics as well as through comparison with the quaternary glaciations with numerical ages in western chinese mountains these moraine groups represent the modern moraine the little ice age neoglacial the late stage of the last glaciation and the early stage of the last glaciation respectively the granite boulders of moraine v are scattered for 6 km from the mountain front on an extensive peneplain this suggests that the ancient glaciers in the west slope of the ice field advanced to the piedmont during the late pleistocene but did not integrate with the ice in the mountains nearby to form a unified ice sheet

accelerated glacier mass loss 2011 2016 over the puruogangri ice field in the inner tibetan plateau revealed by bistatic insar measurements abstract the temporal variation of glacier mass balance during recent years remains poorly known for the mountain glaciers in the inner tibetan plateau itp due to the lack of field measurements in this study we retrieved the annual glacier mass balance of the puruogangri ice field which is the largest modern ice mass in the itp by differencing multi temporal digital elevation models dems generated with five pairs of tandem x bistatic interferometric synthetic aperture radar insar images acquired between april 2011 and january 2016 we compared the tandem x dems in january and april 2012 to estimate the x band radar penetration depth difference 0 61 0 06 m which enabled systematic bias correction in the estimation of annual glacier mass balance the observed mass balance reveals a glacier mass gain of 0 44 0 10 m w e yr 1 in 2011 12 which was followed by accelerated glacier mass loss in 2012 16 glacier mass balances of 0 13 0 03 0 34 0 06 and 0 52 0 10 m w e yr 1 were estimated for the periods of 2012 13 2013 14 and 2014 16 respectively this accelerating trend of glacier mass loss is likely caused by the continuous decrease in annual precipitation according to the climate data recorded by adjacent meteorological stations this study demonstrates that repeated bistatic insar measurement is a promising method for monitoring glacier elevation change and mass balance at regular intervals

relative dating of quaternary moraines rongbuk valley mount everest tibet implications for an ice sheet on the tibetan plateau abstract relative dating studies applied to high altitude moraines 5000 5500 m in the rongbuk valley on the northern flank of mt everest reveal strong contrasts in the weathering characteristics of the boulders exposed along moraine crests these differences serve to define three intervals of major pleistocene glaciation that on the basis of the degree of weathering are interpreted to extend back to at least the penultimate glaciation and probably encompass at least one still older glaciation either interpretation indicates that some of these moraines are considerably older than their previously assigned ages the magnitude of equilibrium line lowering during neoglacial and late pleistocene times is calculated to be ca 50 100 and 350 450 m respectively the data described here are incompatible with the recently proposed model kuhle 1987 for large scale ice sheet development on the tibetan plateau the reconstructed equilibrium line lowering in the everest region is only 30 of that cited in the ice sheet model moreover the flow patterns and geometry of the former rongbuk glaciers are in opposition to those proposed by the model based on the data from the everest region it appears that valley glaciation rather than ice sheet growth characterized the southern margin of the tibetan plateau during the middle and late pleistocene glaciations