a positive altitude gradient of isotopes in the precipitation over the tianshan mountains effects of moisture recycling and sub cloud evaporation abstract a negative stable isotope altitude gradient is commonly observed on the windward side of a mountain however after the precipitation passes over a mountain range to the leeward side the altitude effect becomes ambiguous as a result of an orographic rain shadow in addition to other complex processes such as sub cloud evaporation and additional moisture mixing in this study we found a positive precipitation 18 o altitude gradient with a value of 0 12 100 m in the urumqi river catchments on the leeward side of the tianshan mountains through an analysis of water isotopes sampled in this region processes including both sub cloud evaporation and moisture recycling were found to be responsible for the positive gradient a simple model was built to analyze the observations quantitatively we defined the difference of the recycled evaporated fraction as the recycled evaporated fraction at the lower station minus the fraction at the higher station the model showed that the 18 o altitude gradient rises by 0 28 100 m with the difference of the recycled fraction increasing by 1 100 m and declining by 0 15 100 m with the difference of the evaporated fraction increasing by 1 100 m the effect of moisture recycling is more significant than that of sub cloud evaporation on the leeward side of the tianshan mountains therefore the precipitation in the tianshan mountains has a positive 18 o altitude gradient the model also explains the distribution of water isotope data points in the 2 h 18 o figure of northwest china while the data points of the mountainous water isotopes are located above the local meteoric water line lmwl because of moisture recycling most data points of basin water isotopes are located below the lmwl because of evaporation accordingly we concluded that the stable isotope altitude gradient on the leeward side of a mountain is very sensitive to local atmospheric processes an inference that should be taken into consideration while quantifying the paleo altitude of orogeny and groundwater recharge area using stable water isotopes

empirical relationship between leaf wax n alkane δd and altitude in the wuyi shennongjia and tianshan mountains china implications for paleoaltimetry article i nfo estimating past elevation not only provides evidence for vertical movements of the earth s lithosphere but also increases our understanding of interactions between tectonics relief and climate in geological history development of biomarker hydrogen isotope based paleoaltimetry techniques that can be applied to a wide range of sample types is therefore of continuing importance here we present leaf wax derived n alkane d dwax values along three soil altitudinal transects at different latitudes in the wuyi shennongjia and tianshan mountains in china to investigate dwax gradients and the apparent fractionation between leaf wax and precipitation ewax p we findthatsoil dwax trackaltitudinal variationsof precipitation d along the three transects that span variable environment conditions and vertical vegetation spectra an empirical dwax altitude relation is therefore established in which the average dwax lapse rate of 2 27 0 38 100 m is suitable for predicting relative paleoelevation change relative uplift the application of this empirical gradient is restricted to phases in the mountain uplift stage whenthe atmospheric circulation had not distinctly changed and to when the climate was notarid anempirical dwax latitude altitudeformulaisalsocalculated dwax 3 483lat 0 0227alt 261 5 which gives the preliminary spatial distribution pattern of dwax in modern china meanvalue of ewax p intheextreme humid wuyimountainsisquite negative 154 compared to the humid shennongjia 129 and the arid but with abundant summer precipitation tianshan mountains 130 which suggests aridity or water availability in the growing season is the primary factor controlling soil sediment ewax p along the tianshan transects values of ewax p are speculated to be constant with altitude while along the wuyi and shennongjia transects ewax p are also constant at the low mid altitudes but become slightly more negative at high altitudes which could be attributed to overestimates of precipitation d or the vegetation shift to grass conifer additionally a reversal of altitude effect in the vertical variation of dwax was found in the alpine zone of the tianshan mountains which might be caused by atmospheric circulation change with altitude this implies that the paleo circulation pattern and its changes should alsobe evaluated whenstable isotope based paleoaltimetry is applied

soil n alkane δd and glycerol dialkyl glycerol tetraether gdgt distributions along an altitudinal transect from southwest china evaluating organic molecular proxies for paleoclimate and paleoelevation abstract organic molecular proxies provide a record of the hydrogen isotopic composition of ambient precipitation and paleoenvironmental temperature in terrestrial settings two classes of organic biomarkers are commonly utilized to reconstruct these past environmental conditions straight chained normal alkanes n alkanes and branched glycerol dialkyl glycerol tetraethers brgdgts we measured the dn alkane and the ratio of cyclisation and methylation indexes of branched tetraethers cbt mbt from surface soils along a 1000 km transect along the southeast margin of the tibetan plateau to assess how these proxies record changes in climate parameters that are related to elevation despite variations in ecosystem abundance weighted dnc27 31 data record the d of precipitation across the orogen and indicate minimal change in apparent fractionation en alkane water 133 with elevation n alkane d mirrors the pattern of rayleigh distillation of an air mass undergoing rainout as moisture moves from the bay of bengal into the se margin of the tibetan plateau soil tetraether temperatures provide a reliable measure of modern temperature with an mbt cbt calculated temperature lapse rate 5 8 c km close to the moist adiabat these data reflect ground level conditions that are independent of the shape of the orogen or the source of moisture in combination with a rayleigh distillation model that incorporates temperature and precipitation isotope data paired tetraether temperature and leaf wax isotope data produce a reliable record of changes in environmental conditions associated with modern elevation change across the largest orogen however some tetraether calibrations may impart systematic temperature bias most notably in cold or dry climates these calibration uncertainties can result in underestimates of paleoelevations by up to 1 5 2 km paired isotopic and temperature paleoelevation reconstructions can minimize errors associated with an individual proxy method however we recommend that application of tetraether temperature paleoelevation reconstruction take potential calibration biases into account in paleoelevation estimates

the late cenozoic landscape development in the westernmost mediterranean southern spain abstract the terrains of the western costa del sol in the westernmost mediterranean represent an outstanding example of the influence of major tectonic and climatic factors in the development of the landscape this region belongs to the alboran domain which is a small continental lithosphere fragment embedded between the large eurasian and african plates the territory between malaga and marbella is composed mainly of the sierra de mijas and three adjacent subsidence areas malaga torremolinos and fuengirola basins from the late miocene dip faults of approximate directions n s ne sw and nw se limited the sierra de mijas with respect to the adjacent subsidence areas and have marked the main features of the coastal morphology since then the sierra underwent mainly erosive processes linked to strong uplifting while the surrounding basins were subjected to alternate stages of sedimentation and erosion thus the paleogeographic and geomorphological evolution has been driven both by the regional tectonics and by significant base level changes ranging from the spectacular messinian low stand to the catastrophic overflow at gibraltar followed by the global late tertiary and quaternary sea level changes in the mountain relief three different erosive leveling surfaces have been recognized which developed in a staggered sequence during the miocene and are currently fragmented by tectonics at different elevations the first two leveling surfaces continental in origin were carved during the middle miocene pro part the late one correlating with upper miocene marine deposits from the malaga basin appears to correspond partially to an abrasion platform developed during the highstand of the late tortonian the strong incision of the fluvial network especially due to the low sea level during the messinian salinity crisis but also to the tectonic rise of the sierra has largely eroded these surfaces which can be recognized only in narrow inter fluvial areas the noteworthy marine transgression in the miocene pliocene transition reached the edge of the sierra de mijas developing both a broad marine abrasion platform around it and the main stage of sedimentary filling in the malaga basin tectonics combined with sea level changes influenced the formation of a lower second abrasion platform in the torremolinos sector and along the s edge of the sierra showing continuity with the late zanclean marine deposits in the torremolinos and fuengirola areas during most of the late pliocene and the gelasian the region remained emerged and subjected to erosion conversely climate eustatic changes throughout the pleistocene and holocene led to the development of three major generations of progradant alluvial fans interrupted by stages of erosion and incision of the fluvial network in parallel up to five episodes of travertine build up occurred usually coinciding with the humid and warm odd numbered isotopic stages

stable isotope based paleoaltimetry abstractthe quantitative estimation of paleoaltitude has become an increasing focus of earth scientists because surface elevation provides constraints on the geodynamic mechanisms operating in mountain belts as well as the influence of mountain belt growth on regional and global climate the general observation of decreasing 18o and 2h values in rainfall as elevation increases has been used in both empirical and theoretical approaches to estimate paleoelevation these studies rely on the preservation of ancient surface water compositions in authigenic minerals to reconstruct the elevation at the time the minerals were forming in this review we provide a theory behind the application of stable isotope based approaches to paleoaltimetry we apply this theory to test cases using modern precipitation and surface water isotopic compositions to demonstrate that it generally accords well with observations examples of the application of paleoaltimetry techniques to himalaya tibet and the andes are discussed

biomarker reconstruction of the early eocene paleotopography and paleoclimate of the northern sierra nevada we reconstruct ancient temperature and elevation gradients across the early eocene 52 49 ma northern sierra nevada california united states using organic molecular proxies that record atmospheric and ground level effects of topography paleoelevation was determined by reconstructing the change in the hydrogen isotopic composition of precipitation d precip and mean annual temperature t gdgt glycerol dialkyl glycerol tetraethers from the isotopic composition of fossil angiosperm leaf n alkanes and the distribution of microbially produced soil tetraethers preserved in leaf bearing sediments organic molecular data produce equivalent range scale d n alkane and channel t gdgt paleoelevation estimates that show the northern sierra nevada was a warm 6 8 c warmer than modern high elevation 2 km and moderate to low relief landscape at the eocene climatic optimum modern northern sierra nevada topography likely refl ects post paleocene reduction of mean surface elevation and late cenozoic increases in relief

empirical relationships between elevation and the stable isotope composition of precipitation and surface waters considerations for studies of paleoelevation change a compilation of 68 studies from throughout many of the world s mountain belts reveals an empirically consistent and linear relationship between change in elevation and change in the isotopic composition of precipitation along altitudinal transects the isotopic composition of precipitation decreases linearly with increasing elevation in most regions of the world except in the himalayas and at elevations 5000 m there are no significant differences in isotopic lapse rates from most regions of the world 0 28 permil 100 m except at the extreme latitudes where isotopic lapse rates are higher given information on past changes in the isotopic composition of precipitation preserved in pedogenic or authigenic minerals this global isotopic lapse rate can be used to place numerical constraints on the topo graphic development of some ancient mountain belts or plateaus there are many complicating factors that can confound interpretation of paleoel evation change based on stable isotopes and many of these are unique to specific mountain belts or time periods relevant to all stable isotope based paleoelevation change studies is the temperature dependent isotope fractionation between a pedo genic or authigenic mineral and the water from which it forms in cases where isotopic proxy minerals are sampled from localities where temperature will change simulta neously with elevation change the apparent change in the isotopic composition of precipitation may be dampened by several permil this suggests that samples taken from the rainshadow side of an emerging orographic barrier may be more likely to preserve isotopic changes resulting from mountain uplift than samples taken from atop a rising mountain range or plateau

ca chloride brines at common outlets of the bet shean harod multiple aquifer system israel abstract the bet shean and harod valleys are regional recipients and mixing zones for groundwaters draining into them from a multiple aquifer system which includes carbonate and basalt aquifers and deep seated reservoirs of brine the outlets of the three aquifers are located at the mountain border separating the valleys from the gilboa and ramot issakhar mts the aquifers drain through two types of outlets unique and common the latter type is mainly conditioned by the occurrence of fault blocks acting as connecting media between the aquifers upon reaching the interconnecting zones fresh groundwater flowing from carbonate and basalt aquifers intermix losing their hydrochemical identities ca chloride brines originating from deep seated and confined reservoirs leak along the deep seated faults characterizing the common outlet zones and contaminate the relatively fresh mixing products originating from the three regional aquifers two types of dilute ca chloride brines were identified in the study area the devora type is a hot and hypersaline source brine which was identified at great depth and under very high hydrostatic pressures this brine could be the residual product of seawater that evaporated during the cambrian cretaceous continental interval and subsequent prolonged interaction with surrounding carbonate rocks the neve ur type brine seems to be genetically related to the neogene inland sdom sea that preceeded the contemporary dead sea

biomarkers of modern plants and soils from xinglong mountain in the transitional area between the tibetan and loess plateaus abstract organic compounds found in living plants and modern soils in different bioclimatic areas are important in understanding the paleoenvironmental implications of the organic matter signals from geological records using gc ms techniques a series of biomarkers mainly including n alkanes and n alkan 2 ones were identified from the typical plants e g broadleaf deciduous trees and conifers and the soils collected from xinglong mountain a transitional area between tibetan and loess plateaus the c 15 c 33 n alkane homologues were present in all samples typically c 27 or c 29 n alkanes were most abundant in tree samples and c 31 was most abundant in grasses samples meanwhile the soil samples were mainly dominated by c 29 and c 31 homologues the n alkan 2 ones showed a strong odd over even predominance of carbon numbers c 23 c 25 or c 29 n alkan 2 one homologues were most abundant in plant samples while c 27 or c 29 was abundant in soils samples the lipid biomarker distribution patterns of all the plants and soil samples suggest that the vegetation is a primary source of organic matter for the soils and that reprocessing of microbes and physicochemical reactions in the soil played an important role in the degradation of organic matter research has advanced knowledge about transformation of biomarkers in the plants organic matter microbes forest system it also can help reconstruct the process of plant successions recorded by the lipids

paleoenvironmental reconstruction of the late santonian songliao paleo lake the late cretaceous is often characterized as having a variable greenhouse climate however the relatively few continental sites preserving geologic records from this time exist limiting information on terrestrial climate and environments worldwide the songliao basin slb of northeastern china is one of the largest cretaceous age continental rift basins thus this well preserved lacustrine deposit provides a unique record of terrestrial paleoenvironmental conditions during the cretaceous here we report organic geochemical data from late cretaceous age lacustrine deposits lower nenjiang formation from the eastern side of the slb outcrop samples were collected from the houjingou section and the following analyses were performed 1 total organic carbon toc content and isotopic composition 2 biomarker distribution including the identification and determination of relative amounts of both aliphatic and aromatic hydrocarbons and steranes and 3 compound specific stable carbon and hydrogen isotopic compositions of n alkanes the biomarker distribution and stable carbon isotopic values 13c of the toc indicate organic matter om from the uppermost section of the first member of the nenjiang formation upper k2n1 was mainly sourced from aquatic macrophytes and land plants in the lower part of the second member of the nenjiang formation lower k2n2 the biomarker distribution and 13c of both the toc and n alkanes indicate that om was sourced from a mixture of algae bacteria and higher plants as a result of marine transgression seawater incursions indicated by the presence of 24 n propyl cholestanes and 24 iso propyl cholestanes occurred episodically in lower k2n2 the negative hydrogen isotopic composition 2h of short chain n alkanes in lower k2n2 indicates an extremely humid environment and it is likely that an influx of freshwater caused large scale flooding of the songliao paleo lake high resolution biomarker and stable isotope records from the houjingou section demonstrate abrupt environmental changes in the songliao paleo lake following seawater incursions during the late cretaceous

paleoelevation measurement on the basis of vesicular basalts the vesicles bubbles in basaltic lava flows can be used to determine paleoelevation at the time of eruption in the repertoire of paleoelevation proxies presently available to the research community it represents one of very few direct proxies of elevation the technique is based on the sizes of vesicles at the tops and bottoms of lava flows we assume that bubbles do not know a priori that they will reside in one part of the flow or another when they are erupted from a volcanic vent as such the mass of gas is evenly distributed throughout the flow the volume of the bubbles will therefore depend on pressure which at the top of the flow is just atmospheric pressure and at the bottom is atmospheric plus hydrostatic pressure from lava overburden since lava thickness can be measured in the field and bubble size distributions most notably the modal size can be measured in the lab a simple relation can be solved for atmospheric pressure and using the standard atmosphere elevation can be determined the key parameters that must be determined are lava flow thickness at the time of emplacement and cooling of the upper and lower parts of the flow and the sizes of the vesicles each of these requires some analysis measured flow thickness in the field is not necessarily the same as that during solidification of the upper and lower several cm of the flow as inflation and deflation of the flow could have occurred thus changing the thickness from that which provided lava overburden to determine vesicles sizes in the lower part of the flow lava flows must be examined in cross section in the field to ensure that the indications of inflation or deflation are absent either would alter the proper vesicularity profile as a function of stratigraphic position within the flow for a given flow thickness only flows displaying the correct vesicularity profile can be meaningfully sampled vesicle sizes can be measured in a number of ways but the most accurate is computed x ray tomography which provides 3d information regarding size shape distribution and connectivity of vesicles in a sample we have developed numerical routines for extracting quantitative size distributions from tomographic data the basalt paleoaltimeter can be applied to any tectonic region in which basalts are present we tested the method by measuring the elevation of mauna loa hawaii and then as a first application to a tectonic issue placed constraints on the timing of uplift of the colorado plateau while further testing of this tool for paleoelevation analysis would always be helpful the technique is sufficiently refined for general use by the geologic community provided appropriate samples are collected from lavas demonstrating simple emplacement history and vesicle sizes are measured with sufficient quantitative accuracy to resolve elevation to within a few hundred meters as for any proxy the best results can be obtained with multiple sampling and when possible multiple independent proxies for the most reliable determination of paleoelevation history

the inverse altitude effect of leaf wax derived n alkane δd on the northeastern tibetan plateau the response of soil wax derived n alkane hydrogen isotope values ddwax the abundance weighted average dd values of the c29 and c31 n alkanes and isotopic lapse rates the average change in ddwax with elevation to factors other than elevation change should be assessed and taken into account for quantitative elevation reconstructions to shed more light on how plant wax derived n alkanes may be used for this purpose soil and gramineae samples analyzed for ddwax values those were derived from the foreland basin the mountain vegetation zone and glacier catchment areas along the beida river a tributary in the heihe river basin up to the headwaters of the qiyi glacier and the xiying river catchment up to the headwaters and glaciated areas of the lenglong range located on the northeastern tibetan plateau for comparison this study analyzed surface soils from the maxian mountains for ddwax as a whole the trend in ddwax in the study regions seems to primarily reflect ddrw dd values of river water and or ddp dd values of precipitation these data show good inverse linear relationships between gramineae and soil ddwax values and elevation altitude effect in the mountain vegetation zone of the xiying river catchment 2200 3500 m and maxian mountains 2800 3700 m where the elevation effect becomes the main control factor even in the dry qilian mountains however at the low elevation sites soil and gramineae ddwax values from the xiying river 1750 2200 m and maxian mountains 2060 2800 m show the inverse altitude effect the recycled fraction and trajectory of water vapor may result in these positive ddwax elevation gradients in dry continental settings the inverse altitude effect has also been observed in periglacial regions below the qiyi glacier and from the lenglong range we interpret this effect as evidence of stronger fractionation processes occurring in the freeze thaw mass exchange between the solid and liquid phases at high elevations thus the inverse altitude effect can be attributed to the decrease of precipitation amount in the upper valley and to marked fractionation in soil water and the residual or melting snow in periglacial regions which may complicate the isotope thermometry when interpreting changes of long term dd and d 18

hydrological and hydrogeochemical methods for the delineation of complex groundwater flow systems as evidenced in the bet shean valley israel abstract the bet shean valley northern israel is the base level of groundwater draining from three regional aquifers in the natural undisturbed state i e at the beginning of the six ties groundwater drained through many springs with widely different chemical composition and with a total discharge of about 135 million m 3 for the efficient utilization of water resources it was decided to recover groundwater from wells at the cost of a considerable reduction of spring discharges since the sequence and the rate of spring decay diverged from the pattern that had been predicted it became necessary to delineate aquifers and their connections to the various springs three groups of methods were employed for this purpose a analysis of discharge characteristics and their relation to source aquifers b methods for the identification of well fields that affect the discharge of a particular spring and c hydrogeochemical methods for the delineation of flow paths the paper presents the relevant data the methods employed and the results that were achieved the utility and the limitations of the various methods were discussed and general guidelines for the delineation of groundwater flow in multi aquifer systems were formulated

sedimentary patterns in perched spring travertines near granada spain as indicators of the paleohydrological and paleoclimatological evolution of a karst massif perched spring travertines of the granada basin south spain constitute a perched system with four well defined steps which are formed by several facies associations deposited in different sub environments travertine pools dams and cascades these perched travertines are considered as a freshwater reef system with a facies zonation and stratigraphic architecture closely resembling that of marine reef terraces and prograding carbonate platforms the travertine deposits have been dated by 230 th 234 u and 14 c methods as in other mediterranean areas the travertine deposition occurred episodically during warm and wet interglacial periods coinciding with isotopic stages 9 7 and 5 and with the transition between isotopic stages 2 1 during these periods underground dissolution large outflow in the springs and subsequent calcium carbonate precipitation occurred in the same way that evolution of reef systems indicates sea level changes the geomorphology age and architecture of perched spring travertine systems may be used to interpret former climatically controlled changes in outflow in base level marked by the altitude of springs and in the chemistry of spring waters thus aggradation or climbing progradation may indicate an increase of outflow at the spring progradation with toplap is due to a stable base level and conversely dowlapping progradation may signify that the base level was gradually dropping therefore the travertines can be considered semiquantitative indicators of the paleohydrological evolution of karstic massifs and used as an important terrestrial proxy climate record d 2003 elsevier science b v all rights reserved

a review of paleotemperature lapse rate methods for estimating paleoelevation from fossil floras one widely applied method for estimating paleoelevation from fossil floras uses the relation between vegetation and temperature to estimate mean annual temperature from two isochronous fossil assemblages one at elevation and one at or near sea level and the difference between these temperatures is multiplied by the reciprocal of a temperature lapse rate to estimate paleoelevation three fundamentally different approaches have been developed and these vary both in the method by which paleotemperatures are estimated and in the way by which modern lapse rates can be measured paleotemperature methodologies include the use of plant physiognomy or the use of nearest living relatives lapse rate methodologies use either a global terrestrial lapse rate as the world mean a regional terrestrial lapse rate that represents a large portion of a continent or a local terrestrial lapse rate for areas narrowly confined by latitude and longitude other variables and or corrective factors that should be considered in these applications include the thermal effects of continentality and elevated land surfaces in the continental interior and standardization to compensate for fluctuations or variability in sea level global climate change and paleolatitude these different methodologies can be contrasted by their common application to the late eocene florissant flora of colorado with results ranging from 455 to 4133 meters

stable isotope based paleoaltimetry theory and validation paleoaltimetry is the quantitative estimate of the surface height above mean sea level of ancient landforms atmospheric thermodynamic modeling of the behavior of 18o relative to 16o during condensation from water vapor establish the systematic relationship that exists between 18o p and elevation where 18o p is the difference between a low altitude preferably sea level 18o p and a potentially high elevation sample comparison of model predictions with observations suggests that the model captures the first order behavior of 18o p during condensation and precipitation in orographic settings the actual relationship between 18o p and elevation depends sensitively on climate and specifically starting temperature and to a lesser degree relative humidity thermodynamic modeling allows the 18o p and elevation relationship to be explicitly calculated for any given starting climate state this makes the theoretical approach significantly more appropriate than empirically calibrated approaches based typically on quite limited samples presently available in most orographic settings today paleoaltimetry archives derive their isotopic compositions from surface and or ground water and hence it is important to understand the systematic differences between these reservoirs and precipitation surface waters and ground waters integrate not just the change in isotopic composition with altitude but also variations in hypsometry within the drainage basin and precipitation amount as functions of elevation thus these archives should reflect the precipitation amount weighted hypsometric mean elevation of the paleo drainage basin from which they derive their waters analysis of modern data from the himalayan region supports this expectation foreland basin rivers are such integrators and it is shown using an example from the siwaliks that the rivers draining the front of the himalayas in the past had isotopic compositions comparable with modern rivers draining the himalayan front suggesting little net change in himalayan hypsometry over the past 11 million years

orographic precipitation isotopic ratios in stratified atmospheric flows implications for paleoelevation studies an idealized fully nonlinear atmospheric model was used to evaluate the effects of stratified atmospheric flows on orographic precipitation isotopic ratios with the aim of improving the foundation for interpreting proxy records used for paleoelevation studies orographic precipitation isotopic ratios can be understood in terms of two nondimensional parameters the flow parameter nh u where n is the moist brunt vaisala frequency a measure of atmospheric stratification h is the large scale relief and u is the upstream horizontal wind speed perpendicular to the orogen and the horizontal aspect ratio the ratio of the along strike length of the orogen to its across strike width existing rayleigh condensation models for paleoaltimetry studies are only strictly applicable when nh u 0 much of the time high values of both nh u and favor precipitation upstream of the terrain leading to isotopic ratios that are more depleted than predicted by the rayleigh model high nh u and low favor low level deflection of winds around the terrain which substantially reduces lifting and condensation leading to precipitation isotopic ratios in that are less depleted than predicted by the simple rayleigh model changes in climate or the horizontal terrain aspect ratio can change precipitation isotopic ratios at least as much as changes in surface elevation and surface uplift need not always affect precipitation isotopic ratios suggesting that proxy records must be interpreted within a broad context of climate variability and landscape evolution

hydrogen isotope ratios of recent lacustrine sedimentary n alkanes record modern climate variability abstract hydrogen isotope ratios were measured on n alkanes n c12 to n c31 extracted from recent lake surface sediments along a n s european transect to test if modern climate variability is recorded in these biomarkers d values of the n alkanes are compared to d values of meteoric water from the iaea gnip database spanning a range from 119 in northern sweden to 41 in southern italy to lake water d values and to mean annual temperatures varying between 2 0 c in the north and 13 7 c in the south d values of the short chained n alkanes n c12 to n c20 excluding algal derived n c17 and n c19 are higher in the north and lower in the south the isotopic fractionation e for hydrogen between meteoric water and the short chained n alkanes is increasing from n to s by more than 100 and is significantly correlated to mean annual temperature for n c16 and n c18 this suggests that these n alkanes may originate from a different source in the northern lakes possibly due to petroleum contamination or are synthesized using a different biochemical pathway the n c17 and n c19 alkanes of algal origin the n c21 and n c23 alkanes originating from water plants and the long chain n alkanes n c25 n c27 n c29 and n c31 of terrestrial origin clearly correlate with d values of meteoric water lake water and mean annual temperature indicating that they excellently record the d value of meteoric water the mean hydrogen isotope fractionation ec17 w of 157 sd 13 between n c17 and meteoric water is fairly constant over the wide range of different climates and lake environments suggesting only minor influence of environmental factors on this biochemical fractionation this suggests that d values of n c17 are suitable to reconstruct the isotopic composition of source water the mean fractionation between the long chain n alkanes and water is 128 sd 12 the mean difference of 31 between both e values is likely due to evaporative enrichment of deuterium in the leaf water if this is the only influence on the enrichment the difference between the d values of terrestrial and aquatic compounds might be suitable to reconstruct terrestrial evapotranspiration of the lake environment

paleoelevation records from lipid biomarkers application to the tropical andes new results from two novel lipid biomarker based proxies help to constrain the late cenozoic surface elevation history of the eastern cordillera in the tropical northern andes of colombia previous well known studies have suggested rapid latest miocene pliocene 6 3 ma uplift on the basis of an abrupt shift in pollen species assemblages within sedimentary basin fill of the elevated bogota plateau from resampling of these original study localities we provide a revised chronology based on magnetic polarity stratigraphy and we evaluate paleotemperatures using the mbt cbt indices methylation of branched tetraethers cyclization of branched tetraethers and hydrogen isotopic composition d of leaf waxes as two independent proxies of past surface elevation reconstructed paleotemperatures from the mbt cbt proxy show a more gradual cooling trend from ca 7 6 ma to present consistent with less than 1000 m of elevation gain since latest miocene pliocene time and in agreement with geologic evidence for accelerated shortening and exhumation at this time the leaf wax isotopic data on the other hand lack a systematic trend potentially due to fractionation changes associated with uplift induced turnover in floral populations such changes could obscure isotopic variations in meteoric water suggesting that leaf wax isotopic compositions may not provide a direct proxy for elevation in this particular situation involving uplift in a heterogeneous tropical environment more promising in this case is the mbt cbt proxy which may offer a suitable alternative to carbonate based paleoelevation proxies in tropical regions where year round high precipitation rates prevent formation of soil carbonates

different altitude effect of leaf wax n alkane δd values in surface soils along two vapor transport pathways southeastern tibetan plateau abstract here we present 76 hydrogen isotope values for leaf wax derived n alkanes d wax being the abundance weighted average d values of c 29 and c 31 n alkanes in surface soils along two vapor transport pathway transects running across the southeastern tibetan plateau tp the first is the south himalayan sh transect with an altitude range of 1660 5050 m above sea level and representing the southern himalayan air mass and the second a combination of the zayu bomi zb altitude 1468 4800 m and bayi lhasa bl altitude 3050 4970 m transects together representing the brahmaputra yarlung zangbo river valley air mass d wax values and their relation to altitude did exhibit some variability nonetheless altitude was the predominant factor in determining soil d wax values with a lapse rate of 2 2 100 m r 2 0 78 n 76 based on overall soil d wax values despite changes in precipitation amount relative humidity rh and vegetation type furthermore our e wax rw values the isotopic fractionation between the d wax and d values of river water d rw remained approximately constant at 104 5 ranging between 99 and 110 confirming that the relation between altitude and isotopic hydrology river water and precipitation controls the n alkane d wax altitudinal gradients for all of the sample localities in the southern himalaya sh and the southern tp this endorses the efficacy of using d wax to reconstruct paleoelevation along the sh transect soil d wax values varied from 151 to 264 with an altitudinal lapse rate of 2 4 100 m r 2 0 84 n 32 this was due to the significant change in altitude over short distances along the zb transect soil d wax values varied from 174 to 263 with a lower lapse rate of 1 9 100 m r 2 0 68 n 29 the altitudinal lapse rate was 3 3 100 m above 3000 m r 2 0 63 n 19 and 1 35 100 m below 3000 m r 2 0 64 n 10 in the lower sub transect the latitudinal effect significantly counteracted the altitude effect along the bl transect soil d wax values varied from 205 to 244 with an altitudinal lapse rate of 1 4 100 m r 2 0 74 n 15 the lower lapse rate for soil d wax reflects a combination of local continental and altitudinal effects the differences we observed in soil d wax altitudinal lapse rates along the two vapor transport pathways imply that they are affected by subtle local environmental conditions moisture sources latitude and topography this should be considered fully during any reconstruction of paleoelevation

evaluation of leaf wax δd and soil brgdgts as tools for paleoaltimetry on the southeastern tibetan plateau abstract the orogenic history of the tibetan plateau tp and surrounding mountain ranges continues to be a major source of disagreement among geologists particularly concerning the uplift models for the cenozoic evolution of the tp and estimates for when the highest and largest plateau on earth reached its current elevation quantitative reconstructions of past elevation from geologic samples are necessary to document the uplift history of tp and examine the interactions between tectonic relief and climate over geological time scales several studies establishing lipid biomarker based paleoaltimetry based on leaf wax d values and brgdgts have been reported in recent years for the tp and surrounding regions but have yet to be synthesized into a regional framework for paleoelevation determination and uncertainty analysis here we report new leaf wax d and brgdgts data developed from surface soil samples along an elevation transect spanning 1250 3900 m a s l in the hengduan mountains on the southeastern edge of the tp we find that the abundance weighted mean leaf wax d n c27 n c29 and n c31 values dwax lapse rates determined for the hengduan mountains and for five other nearby study locations are statistically indistinguishable and can be combined to provide a regional dwax lapse rate of 1 97 0 04 1 100 m for use in regional paleoelevation studies across the southeastern tp we also find a strong correlation r2 0 71 between brgdgts and elevation dependent mean annual air temperature which contributes to a number of studies in the region that support the use of fossil brgdgts as a paleoelevation proxy our results reveal that dwax and brgdgts for the hengduan mountains provide similar empirical uncertainty in paleoelevation reconstruction with standard errors of elevation estimation se of 483 m 1 and 394 m 1 respectively we propose a paleoaltimetric approach that combines dwax and brgdgt data in order to derive paleoelevation estimates with lower uncertainties in the hengduan mountains data set the approach yields a se 286 m 1 that is 27 40 lower than when dwax values and brgdgts are applied separately

spatial patterns of soil n alkaneδd values on the tibetan plateau implications for monsoon boundaries and paleoelevation reconstructions 1 between 2010 and 2011 this project collected and analyzed forty nine superficial soil samples for wax derivedn alkane d values dwax along a south to north transect of the tibetan plateau from the southern plateau and nepalese himalayas passing through the nam co basin to qilian mountains twenty two paired river water samples were also collected from northeastern tibet during this period and analyzed for d drw the drw and dwaxvalues become progressively more negative northward from 27 5 n and reach a minimum at 30 6 n nam co basin north of the nam co basin to 35 n isotope values increase due to increasing contributions from the year round westerlies and recycled moisture from the plateau relatively high and constant dwax and drw values prevail in areas north of 35 n in northeastern tibet results show that these dwaxvalues vary considerably with location and relate closely to the influences of the summer monsoon and circulation changes these changes track the spatial variability of isotopes from modern river water and precipitation at large spatial scales paleoelevation reconstructions should take into account the impact of mixing between continental and monsoon derived moisture on the relationships with elevation and dwax and linear isotopic lapse rates for central northeastern tibet based on extended and more sensitive relative to 18o dwax and drw values we infer that in the past the westerlies reached further south to the north piedmont of the nyainqentanglha range and that indian summer monsoon moisture pushes across the tanggula mountains and approaches the kunlun mountains

altitudinal shift in stable hydrogen isotopes and microbial tetraether distribution in soils from the southern alps nz implications for paleoclimatology and paleoaltimetry abstract the southern alps are an ideal locality for studying patterns of isotopic fractionation associated with orographic precipitation we have evaluated whether altitudinal change is reflected in the stable hydrogen isotopic composition 2 h of stream water plant stem water and leaf wax lipids n alkanes from living plants and soils as well as in soil temperature samples were collected along an altitudinal transect from the windward side of the southern alps to lake hawea in the rain shadow the results indicate that 2 h values of stem water overlap with stream water demonstrating a gradual decrease with elevation that complied with modeled rayleigh distillation reflecting an isotopic lapse rate of 18 0 1 1 1 km leaf and soil n alkanes shared similar 2 h values and were 2 h depleted relative to stem stream waters the values for soil n alkanes indicated an isotopic lapse rate of 21 8 2 0 1 km consistent with precipitation data and long term observations mbt cbt derived soil temperature values based on the relative distribution of microbial tetraether lipids were similar to midsummer temperature observations displaying an elevational decrease rate of 5 6 1 5 1 c km consistent with regional and global observations the results indicate that sedimentary lipid 2 h and microbial tetraether temperature estimates captured altitudinal trends in the isotopic composition of precipitation and mean temperature and further support their application in the reconstruction of past climate and surface uplift histories however notable differences in isotopic composition and temperature estimates between in situ soils and those with downslope transport of material emphasize the importance of facies analysis when interpreting past systems

the geology of vertical movements of the lithosphere an overview defining and quantifying horizontal movements of the earth s crust has been a common activity for geoscientists during the last decades due to the success of structural geology in measuring magnitudes of shortening or extension via balanced cross sections and strain analysis coupled with the popularization of continental drift and plate tectonics theory on the larger scale on the other hand vertical movements of rocks or of the surface of the earth although perceived for over two centuries have been more elusive because of the smaller magnitude of translations the difficulties in finding unambiguous markers and because more often their characterization requires the concurrence of integrated approaches some of them recently developed downward movements i e subsidence associated with the formation of sedimentary basins are better quantified and understood but often not coupled with the areas experiencing upward vertical movements over the past decades considerable progress has beenmade in the understanding and quantification of vertical motions of the lithosphere and in particular of the earth s surface thanks to the implementation of new tectonic geomorphologic geochemical and geophysical techniques largely motivated by the strong implications of uplift and subsidence for landscape and environmental issues in addition there is an increased perception that areas experiencing upward and downwardmovements mountains and basins should be looked at as parts of a single tectonic geomorphic and sedimentologic system a significant number of challenges remain to be addressed an inspection of the recent literature clearly indicates that the geology of vertical movements is a field of very active multidisciplinary research the esf sponsored topoeurope initiative with its national counterparts topoiberia toposcandia etc is an obvious demonstration of the increased attention of the geoscience community towards processes controlling the development of continental topography with this in mind on 28 31 september 2007 we convened a workshop entitled the geology of vertical movements uplift and subsidence mountains and basins in the framework of the international lithosphere program s task force on sedimentary basins the workshop was hosted by the 1 convention of the moroccan association of petroleum geologists mapg and the venue was the town of marrakech in the frame of the superb moroccan mountains and basins e g fig 1 which have been the recent objective of many studies thus the workshop intended a particular emphasis on african

evaluation of branched gdgts and leaf wax n alkane δ2h as paleo environmental proxies in east africa the role of mountain evolution on local climate is poorly understood and potentially underestimated in climate models one prominent example is east africa which underwent major geodynamic changes with the onset of the east african rift system ears more than 250 myr ago this study explores at the regional east african scale a molecular approach for terrestrially based paleo climatic reconstructions that takes into account both changes in temperature and in altitude potentially leading to an improved concept in paleo climatic reconstructions using surface soils collected along pronounced altitudinal gradients in mt rungwe n 40 southwest tanzania and mt kenya n 20 central kenya we investigate the combination of 2 terrestrial proxies leaf wax n alkane 2h 2hwax and branched glycerol dialkyl glycerol tetraether br gdgt membrane lipids as paleo elevation and paleo temperature proxies respectively at the mountain scale a weak link between 2hwax and altitude r2 0 33 is observed at mt kenya but no relationship is observed at mt rungwe it is likely that additional parameters such as decreasing relative humidity rh or vegetation changes with altitude are outcompeting the expected 2h depletion trend along mt rungwe in contrast br gdgt derived absolute mean annual air temperature maat and temperature lapse rate 0 65 c 100 m for both mountains are in good agreement with direct field measurements further supporting the robustness of this molecular proxy for paleo temperature reconstructions at the regional scale estimated and observed 2h data in precipitation along 3 mountains in east africa mts rungwe kenya and kilimanjaro highlight a strong spatial heterogeneity preventing the establishment of a regional based calibration of 2hwax for paeloaltitudinal reconstructions different from that an improved regional soil calibration is developed between br gdgt distribution and maat by combining the data from this study mts rungwe and kenya with previous results from east african surface soils along mts kilimanjaro tanzania and rwenzori uganda this new regional calibration based on 105 samples improves both the r2 0 77 and rmse root mean square error 2 4 c of br gdgt derived maat over the global soil calibrations previously established r2 0 56 rmse 4 2 c and leads to more accurate paleo temperature reconstructions in the region

hydrogen isotope ratios of terrestrial leaf wax n alkanes from the tibetan plateau controls on apparent enrichment factors effect of vapor sources and implication for altimetry abstract empirical evidence suggested that the altitudinal dependence of hydrogen isotope ratios of leaf wax n alkanes d wax can be used to estimate paleoaltitudinal changes however the application of d wax based paleoaltimetry remains difficult as the impacts of evaporative transpirative and biosynthetic processes on hydrogen isotope fractionations in changing environments and the influence of likely changing water vapor sources are not well explored for this study we sampled stream waters soils and plant leaves along two transects spanning large gradients of altitude precipitation amount vapor source temperature and vegetation type on the tibetan plateau tp d values of stream water as an approximation for d p soil water d sw and plant leaf water d lw as well as leaf wax n alkanes were measured in order to quantify isotopic fractionations in the formation of leaf waxes most interestingly we found a strong negative correlation between the evapotranspirative enrichment of leaf water against precipitation e lw p which combines the effects of soil evaporation and leaf transpiration and the biosynthetic hydrogen isotope fractionation e wax lw which describes isotopic enrichment between leaf wax and leaf water the relationship yields a steady apparent isotopic enrichment factor e wax p between leaf wax and precipitation which is independent from climatic parameters and has an average value of 107 26 for grasses monocotyledons and 77 22 for trees dicotyledons since the terrestrial n alkanes especially n c 27 and n c 29 in sediments are derived from trees and grasses the likely change of the vegetation type in the uplift of mountains can change the isotopic estimates by about 30 which corresponds to an altitudinal change of 1600 m we therefore suggest that hydrogen isotope ratio of sedimentary n c 31 alkane which is mainly derived from grasses might be better proxies to reconstruct paleoaltitudes our large dataset of d wax from trees and grasses that aimed to mirror the variability of environmental factors over geological time frames showed the lapse rates were significant but much smaller than in previous studies most importantly our result demonstrated that the lapse rate significantly differed for both transects p 0 0068 i e 0 87 0 71 100 m r 2 0 28 p 0 2841 n 6 and 2 28 0 82 100 m r 2 0 34 p 0 0135 n 17 for indian monsoon and westerly dominated areas respectively this suggests that different moisture sources might strongly affected the observed lapse rates in consequences altitude reconstructions are strongly complicated in areas with likely changing air masses like the tibetan plateau

soil n alkane δd vs altitude gradients along mount gongga china the altitude effect on the isotopic composition of precipitation and its application to paleoelevation reconstruction using authigenic or pedogenic minerals have been intensively studied however there are still no studies on variations in biomarker d along altitude transects to investigate its potential as a paleoelevation indicator although it has been observed that d of higher plant lipid may record changes in precipitation d dp here we present d values of higher plant derived c27 c29 and c31n alkanes from surface soil along the eastern slope of mount gongga china with great changes in physical variables and vegetation over a range from 1000 to 4000 m above sea level the weighted mean d values of these n alkanes dwax show significant linear correlations with predicted dp values r2 0 76 with an apparent isotopic enrichment ewax p of 137 9 indicating that soil dwax values track overall dp variation along the entire altitudinal transect leaf dwax is also highly correlated with mountain altitude by a significant quadratic relationship r2 0 80 evapotranspiration is found declining with altitude potentially lowering dwax values at higher elevations however this evapotranspiration effect is believed to be largely compensated by the opposing effect of vegetation changes resulting in less varied ewax p values over the slope transect this study therefore confirms the potential of using leaf dwax to infer paleoelevations and more generally to infer the d of precipitation

leaf wax stable isotopes from northern tibetan plateau implications for uplift and climate since 15 ma abstract the growth of tibetan plateau is considered to have played a key role during the evolution of asian climate our understanding of the relationship between the plateau growth and asian climate changes is limited however due to the scarcity of well dated sedimentary sequences that could provide parallel information of the evolution of elevation and climate here we report a high resolution time series record of the stable hydrogen isotopic composition of leaf wax n alkanes d n alk from a continuous neogene stratigraphic sequence 15 1 8 ma from the qaidam basin on the northern tibetan plateau these data are used to reconstruct the isotopic composition of meteoric waters d m and subsequently applied to interpret the history of paleotopography and climate in qaidam our results indicate four stages in the evolution of hydrology in the qaidam basin in stage i 15 ma to 10 4 ma d m gradually decreases from 24 9 to 75 5 synchronous with a period of active tectonism the estimated topographic growth of 2 1 0 3 km is comparable to the height of qaidam basin relative to the foreland hexi corridor we note that c 3 plants were dominant in this region since the miocene we take this as independent evidence that this area was mountainous before the c 4 expansion in late miocene and pliocene d m variability in subsequent stages appears to be related to shifts in dry and moist conditions and independent of topographical changes a conclusion supported by other independent climatic records on the tibetan plateau high d m values in stage ii 10 4 ma to 6 9 ma are related to severe aridity and stage iii 6 9 ma to 4 1 ma is marked by low d m values suggestive of moist conditions related to the strengthening east asia summer monsoon high d m values in stage iv 4 1 ma to 1 8 ma reflect a climate drier than the present

paleotemperature variability in central china during the last 13 ka recorded by a novel microbial lipid proxy in the dajiuhu peat deposit the asian summer monsoon is a very important climatic component affecting the land ecosystem on the eastern asian continent here we assess microbe derived lipid biomarker evidence from a well date

a new approach to stable isotope based paleoaltimetry implications for paleoaltimetry and paleohypsometry of the high himalaya since the late miocene the change in oxygen isotopic composition of precipitation is modeled using equilibrium fractionation during rayleigh distillation linked to the thermodynamics of atmospheric ascent and water vapor condensation the primary controllers of the vertical variation in isotopic composition with elevation are the low elevation temperature and relative humidity as these control the vertical distribution of condensation an empirical fit of precipitation versus model condensation based on alpine stations is derived this fit is represented in the model as the weighted mean composition of condensation within a 1000 m thick air parcel 1500 500 m above the ground surface and is used for all other regions comparison of model versus observed modern precipitation reveals a close fit particularly of more highly elevated sites comparison of modern waters in the himalayas and southern tibet with model predictions particularly as revealed by comparison of observed and predicted hypsometry provides additional support to the validity of the model finally application of this model to estimates of paleo waters in the himalayas and southern tibet reveals that this region had already achieved its present hypsometry by the late miocene about 10 ma ago fl 2001 published by elsevier science b v

preservation of lipid hydrogen isotope ratios in miocene lacustrine sediments and plant fossils at clarkia northern idaho usa abstract we measured d h ratios of individual lipids isolated from plant fossils and water lain sediments from the miocene clarkia lacustrine deposit 15 20 ma in northern idaho usa in order to assess the preservation potential of lipid hydrogen isotope ratios distinct n alkyl lipid profiles in plant fossils platanus quercus salix and the sedimentary matrix demonstrate the high degree of lipid preservation as previously reported our data suggest that original hydrogen isotope ratios of carbon bound hydrogen in lipids may have been preserved after 15 20 million years of burial in the water lain lacustrine sediment because d values of individual lipids show large variations between different fossil genera and between fossils and sediments and hydrogen isotope values of fossil lipids differ by more than 123 from the associated sediment water these data are consistent with minimal isotopic exchange between carbon bound hydrogen in lipids and sediment water hydrogen our results validate the use of lipid hydrogen isotope ratios for paleoecological studies over an extended geological time period

stable isotopic variations in west china a consideration of moisture sources 1 in this study individual precipitation samples collected over 2 years at stations in different climatic regions of west china tibetan plateau region tianshan region and altay were analyzed for the stable isotopes of precipitation to improve our understanding of how vapor transport impacts the modern stable isotopic distribution our results identify regional patterns in both 18o and deuterium excess d excess defined as d 8 18o and in particular we have identified the northward maximum extent of the southwest monsoon over the tibetan plateau this demarcation is also the boundary for the fractionation effect of temperature on stable isotopes in precipitation the patterns we have identified are as follows 1 in the southern tibetan plateau along the southern slope of the himalayas our results show a distinct seasonality for both 18o and d excess as a result of the shift of summer monsoon moisture and winter westerly moisture transport the signals of 18o in the western tibetan plateau reveal that the region receives southwest monsoonal moisture in the east of the plateau stable isotopic variation shows alternation between monsoon intrusion and recycling of northern moisture 2 in contrast in tianshan there is an apparent temperature effect in 18o with enriched values occurring in summer and depleted values occurring in winter seasonal d excess values opposite to those observed in the southern tibetan plateau are controlled by differing seasonal evaporation conditions 3 in altay the most northern mountain region the seasonal 18o shows the same variation with that in tianshan region however d excess shows no apparent seasonal variation

climatic and hydrologic changes in the tien shan central asia abstract the authors analyze climatic and hydrologic data from 110 sites collected from the middle of the twentieth century to the present in the tien shan one of the largest mountain systems of central asia in spite of a few confounding interregional variations in the temporal changes of surface air temperature precipitation runoff glacier mass and snow thickness in the tien shan it has been possible to establish statistically significant long term trends in these key hydroclimatic variables the average rise in air temperature was 0 01 c yr 1 over the range with slightly lower values below 2000 m elevation the precipitation in the tien shan increased 1 2 mm yr 1 over the past half century the precipitation increase is larger at low altitudes in the northern and western regions than at altitudes above 2000 m a decrease in snow resources occurred almost everywhere in the tien shan the maximum snow thickness and snow duration have decreased on average 10 cm and 9 days respectively the annual

predicting paleoelevation of tibet and the himalaya from δ18o vs altitude gradients in meteoric water across the nepal himalaya the 18o value of meteoric water varies with elevation providing a means to reconstruct paleoelevation if the 18o values of paleowater are known in this study we determined the 18o values of water 18omw from small tributaries along the seti river and kali gandaki in the nepal himalaya we found that 18omw values decrease with increasing altitude for both transects 18omw vs altitude along the kali gandaki in west central nepal fit a second order polynomial curve consistent with increasing depletion of 18o with increasing elevation as predicted by a rayleigh type fractionation process this modern 18omw vs altitude relationship can be used to constrain paleoelevation from the 18o values of miocene pliocene carbonate 18oc deposited in the thakkhola graben in the southern tibetan plateau paleoelevations of 3800 480 m to 5900 350 are predicted for the older tetang formation and 4500 430 m to 6300 330 m for the younger thakkhola formation these paleoelevation estimates suggest that by 11 ma the southern tibetan plateau was at a similar elevation to modern

can sedimentary leaf waxes record d h ratios of continental precipitation field model and experimental assessments abstract d h ratios of leaf waxes d wax derived from terrestrial plants and preserved in lake sediments can provide important information on past continental hydrology ideally d wax can be used to reconstruct precipitation d h ratios d p which is a well established paleoclimate proxy however many other factors such as vegetation and relative humidity rh also affect d wax variation how the combination of these factors affects sedimentary d wax is unclear here we use a transect of 32 lake surface sediments across large gradients of precipitation relative humidity and vegetation composition in the southwestern united states to study the natural factors affecting sedimentary d wax d values of c 28 n alkanoic acids show significant correlation with d p values r 2 0 76 with an apparent isotopic enrichment of 99 8 indicating that sedimentary d wax values track overall d p variation along the entire transect leaf waxes produced by plants grown under controlled conditions rh 80 60 40 show a small increase in d h ratios as rh decreases consistent with prediction from the craig gordon model however the isotopic effect of rh on d wax along the natural transect is partially countered by the opposing influence of vegetation changes the correlation between d wax and d p values is significantly higher r 2 0 84 in the drier portions of the transect than in the wetter regions r 2 0 64 this study suggests that d h ratios of sedimentary leaf waxes can be used as a proxy for precipitation d variations with particularly high fidelity in dry regions although more studies in other regions will be important to further test this proxy

paleoclimate significance of n alkane molecular distributions and δ2h values in surface peats across the monsoon region of china abstract leaf wax molecular distributions and isotopic values are generally considered paleohydrologic proxies here we evaluate the sensitivity of alkane chain length distributions and compound specific hydrogen isotopic compositions 2halk in surface peats to environmental parameters across the monsoon region of china the alkane average chain length acl carbon predominance index cpi and 2halk values show relatively large variations in multiple samples from a single site highlighting the complexity of the processes affecting these ratios at small spatial scales nonetheless the site averaged cpi values correlate significantly with the mean annual temperature r 0 57 p

effect of precipitation regime on δ d values of soil n alkanes from elevation gradients implications for the study of paleo elevation we measured dd values of long chain n alkanes isolated from 30 surface soil samples along two elevation transects on the tibetan plateau differing in precipitation regime and water source the east asian monsoon precipitation dominates the wetter regime on the eastern slope from 1230 to 4300 m of gongga shan on the eastern tibetan plateau precipitation from the polar westerlies dominates the drier region on the slope from 1900 to 5000 m in the west kunlun shan on the northwestern tibetan plateau the decrease in dd value with elevation in the wetter region greatly exceeded that in drier region by 1 9 0 1 100 m and 1 4 1 0 100 m respectively the apparent fractionation between leaf wax and precipitation ewax p values in the wetter region ca 164 were more negative than those in drier region ca 125 above 3200 m we also measured dd values in leaves of six common living trees values from 287 to 193 from gongga shan ranging from about 2900 4200 m the abundance weighted average values of the nalkanes ddwax show a strong reverse correlation with sample source elevation r 2 0 78 for soils from 2 0 85 for soils from west kunlun shan above 3200 m suggesting that n alkane ddwax faithfully records the precipitation dd and that the isotopic altitude effect of precipitation controls ddwax altitudinal gradients in the mountains the data show a fairly strong monotonic dependency of n alkane dd values on elevation for the eastern plateau but a complex relationship between n alkane dd values and elevation for the northwestern plateau the ddwax values at sites below 3200 m from the kunlun shan area exhibit an unexpected positive correlation with elevation the study confirms the potential for using sediment ddwax values to reconstruct paleo elevation in wetter regions but suggests caution in applying the approach to dry regions our results also show it is essential to consider the intricacy of the pattern of atmospheric circulation and water sources and their influence on the lapse rate of dd values with elevation

paleoaltimetry of the tibetan plateau from d h ratios of lipid biomarkers abstract the past elevation of the land surface provides a unique constraint on the underlying lithospheric structure during mountain and plateau formation development of new paleoaltimetry techniques that can be applied to a wide variety of sample types is therefore of continuing importance this study evaluates organic substrates that preserve the d ratio of surface waters as a new approach to reconstruct paleoaltimetry we measured the hydrogen isotope composition of n alkanes from epicuticular plant waxes preserved in lacustrine deposits to reconstruct the d of precipitation in cenozoic basins that have been elevated as part of the tibetan plateau n alkane d and carbonate 18 o inferred water compositions from the eocene miocene lunpola basin and miocene hoh xil basin plot near or at enriched values relative to the global meteoric water line as expected for evaporative lakewater and leafwater systems that have the same precipitation source n alkane d based water compositions are nearly identical to the minimum carbonate 18 o based values demonstrating that plant wax d is minimally affected by evaporation compared to lacustrine calcite 18 o this agreement strongly supports the presence of similar precipitation isotopic compositions in both archives despite different isotope systems source water reservoirs archive materials modes of incorporation and diagenetic processes paleoelevations for each basin and time period were calculated from precipitation isotope ratios using the isotope altitude relationship derived from both a simple thermodynamic model and modern precipitation sampling from the plateau region our new results from the hoh xil basin suggest 1700 to 2600 m of uplift may have occurred some time between the late eocene and early miocene the timing of this uplift is consistent with late oligocene compressional deformation of the hoh xil basin and northward growth of the tibetan plateau however the calculated uplift is not a unique solution from the paleoisotope data because of uncertainties in eocene and miocene moisture sources and isotope gradients for the northern plateau our results demonstrate the utility of lipid based estimates of paleoelevation and expand the types of deposits amenable to paleoaltimetry analysis

paleoelevation reconstruction using pedogenic carbonates paleoelevation reconstruction using stable isotopes although a relatively new science is making a significant contribution to our understanding of the recent growth of the world s major orogens in this review we examine the use of both light stable isotopes of oxygen and the new clumped isotope 47 carbonate thermometer in carbonates from soils globally the oxygen isotopic composition 18 o of rainfall decreases on average by about 2 8 km of elevation gain this effect of elevation will in turn be archived in the 18 o value of soil carbonates and paleoelevation can be reconstructed provided 1 temperature of formation can be estimated 2 the effects of evaporation are small 3 the effects of climate change can be accounted for and 4 the isotopic composition of the carbonate is not diagenetically altered we review data from modern soils to evaluate some of these issues and find that evaporation commonly elevates 18 o values of carbonates in deserts an effect that would lead to underestimates of paleoelevation some assessment of paleoaridity using qualitative indicators or carbon isotopes from soil carbonate is therefore useful in evaluating the oxygen isotope based estimates of paleoelevation sampling from deep 50 cm in paleosols helps reduce the uncertainties arising from seasonal temperature fluctuations and from evaporation the new clumped isotope 47 carbonate thermometer expressed as 47 offers an independent and potentially very powerful approach to paleoelevation reconstruction in contrast to the use of 18 o values nothing need be known about the isotopic composition of water from which carbonate grew in order to estimate of temperature of carbonate formation from 47 values using assumed temperature lapse rates with elevation paleoelevations can thereby be reconstructed case studies from the andes and tibet show how these methods can be used alone or in combination to estimate paleoelevation in both cases the potential for diagenetic alteration of primary carbonate values first has to be assessed clear examples of both preservation and alteration of primary isotopic values are available from deposits of varying ages and burial histories 47 values constitute a relatively straightforward test since any temperature in excess of reasonable surface temperatures points to diagenetic alteration for 18 o values preservation of isotopic heterogeneity between different carbonate phases offers a check on diagenesis results of these case studies show that one area of south central tibet attained elevations comparable to today by the late oligocene whereas 2 7 0 4 km of uplift occurred in the bolivian altiplano during the late miocene

variation of the stable isotopes of water with altitude in the saint elias mountains of canada the stable isotopes of water measured in melt samples taken from snow pits and cores at locations between 1750 and 5930 m altitude on mount logan 5951 m and between 2900 and 4900 m on mount steele 5079 m in the saint elias mountains yukon show a distinctive altitudinal distribution several 18o and d versus altitude profiles indicate the general persistence of a nearly iso step or staircase structure separating a lower region of altitude dependent isotopic fractionation between 1750 and 3350 m from another apparent fractionation sequence appearing above about 5300 m both of these sequences but especially the lower one indicate orderly processes on the one hand postdepositional changes to isotope ratios in snow at different altitudes may cause distortions to an otherwise nearly monotonic isotope fractionation sequence but the main anomaly appears to be far too large to be explained in this way on the other hand an explanation linked to processes occurring in the lower and midtroposphere is based on established meteorological principles as well as on upper air data this hypothesis is proposed as the primary one to explain the gross features of the observed isotope profiles it is compatible with the concept of secondary source moisture arriving via the upper troposphere and it does not exclude the effects of postdepositional stratigraphic and stable isotope ratio changes over interannual time scales any vertical modulation of the observed isotope altitude structure from for example changes in wind regime would give rise to an additional signal in any ice core time series these findings identify a potential difficulty in the interpretation of stable isotope records obtained from high mountain ice core sites it is possible that the results may have application to atmospheric circulation modeling where the effects of extreme topography are being studied

orographic controls on rain water isotope distribution in the mount lofty ranges of south australia summary hydrogen and oxygen isotopes of water are common environmental tracers used to investigate hydrological processes such as evaporation vegetation water use surface water groundwater interaction and groundwater recharge the water isotope signature in surface water and groundwater evolves from the initial rain signature in mountain terrain rain water stable isotope composition spatially varies due to complex orographic precipitation processes many studies have examined the isotope elevation relationships while few have quantitatively investigate the terrain aspect and slope effect on rain isotope distribution in this paper we examine the orographic effects more completely including elevation terrain slope and aspect on stable isotope distribution in the mount lofty ranges mlr of south australia using a multivariate regression model the regression of precipitation isotope composition suggests that orographic effects are the dominant controls on isotope spatial variability about 75 of spatial variability in 18 o and deuterium excess is represented by the regression using solely orography related variables elevation terrain aspect and slope with about 25 of 18 o spatial variability attributed to the terrain aspect and slope effect the lapse rate is about 0 25 for every 100 m at both windward and leeward slopes however at the same elevation 18 o at the leeward slope eastern mlr is 0 5 larger than that at the windward slope the difference can be explained by different mechanisms continuous rain out processes on the windward side and sub cloud evaporation on the leeward side both 18 o and deuterium excess maps 1 km resolution are constructed based on the regression results for the mlr both maps are consistent with groundwater of local precipitation origin and useful to examine groundwater recharge

the significance of paleotopography topographic change is one of the most informative measures of continental deformation yet precise records of past elevation are scarce to non existent in most orogenic belts recent advancement and new development of techniques to measure paleoelevation promise significant progress in understanding continental tectonic processes and how erosion acts on rising topography to shape the earth s surface outstanding issues in continental tectonics include understanding driving forces to deformation how strain is vertically partitioned in the lithosphere and how mass is redistributed or conserved in the lithosphere during deformation geodynamic and mechanical models that explore these topics make testable predictions of topographic evolution this review explores key examples of how paleotopography relates to outstanding issues in continental tectonics that motivate development of robust quantitative measures of paleoelevation

stable isotope paleoaltimetry a critical review stable isotope paleoaltimetry makes use of systematic trends in the distribution and isotopic composition of modern precipitation with climate and topography and of the potential to estimate the isotopic composition of paleoprecipitation from authigenic in situ formed minerals to illustrate the usefulness as well as potential limitations of this method we review 1 processes controlling the isotopic composition of modern precipitation 2 stable isotope data from modern precipitation across regions of high topography and 3 stable isotope data from authigenic minerals that have been used to infer paleotopography from this we conclude that stable isotope studies of authigenic minerals can permit useful inferences on paleotopography with uncertainties that critically depend on a detailed understanding of local to global scale paleoclimate during the time interval of interest

a 1700 year n alkanes hydrogen isotope record of moisture changes in sediments from lake sugan in the qaidam basin northeastern tibetan plateau we present a hydrogen isotopic record of long chain n alkanes in lake sugan to reconstruct regional moisture changes in the last 1700 years at a sampling resolution of 25 years the d values decreased by over 30 from the medieval warm period mwp c ad 600 1500 to the little ice age lia c ad 1500 1850 and indicated that the moisture pattern included a relatively humid climate before the mwp becoming drier overall in the mwp wetter in the lia and then tending towards drought in the post industrial era in the study region chenopodiceae shrubs were more abundant in dry climates than in wet meanwhile d values of shrubs were more positive than those of grasses therefore we suggest that the vegetation type shrub or grass which depends on moisture changes is the controlling factor for d variations in lake sugan

assessment of the difference between mid and long chain compound specific δdn alkanes values in lacustrine sediments as a paleoclimatic indicator abstract previous studies have proposed that the difference between compound specific hydrogen isotopic composition of n alkanes d n alkanes of possible terrestrial origin and aquatic origin in lacustrine sediments is an indicator of hydroclimatic conditions for a lake environment e g terrestrial evapotranspiration of the lake drainage area or evaporation inflow ratio for the lake sachse d radke j gleixner g 2004 hydrogen isotope ratios of recent lacustrine sedimentary n alkanes record modern climate variability geochimica et cosmochimca acta 68 4877 4889 sachse d radke j gleixner g 2006 d values of individual n alkanes from terrestrial plants along a climatic gradient implications for the sedimentary biomarker record organic geochemistry 37 469 483 mugler i sachse d werner m xu b q wu g j yao t d gleixner g 2008 effect of lake evaporation on d values of lacustrine n alkanes a comparison of nam co tibetan plateau and holzmaar germany organic geochemistry 39 711 729 and this proposed indicator has been applied to a paleoclimatic study of koucha lake kcl on the northeastern tibetan plateau netp however the application was not very successful due to an apparent discrepancy between the reconstructed possible hydroclimatic variation based on the proposed indicator and precipitation amount variation based on pollen in the same lake aichner b herzschuh u wilkes h vieth a bohner j 2010a d values of n alkanes in tibetan lake sediments and aquatic macrophytes a surface sediment study and application to a 16 ka record from lake koucha organic geochemistry 41 779 790 we report new compound specific d n alkanes data for sediments since the last glacial from hurleg lake klk and genggahai lake ggh both also on the netp ca 300 km apart together d n alkanes data from the three lakes were analyzed to assess the difference between mid chain and long chain compound specific d n alkanes values in the sediments as a paleoclimatic indicator our results indicate that mid chain n c 23 and n c 25 and long chain n c 27 n c 29 and n c 31 n alkanes as compounds representative of aquatic and terrestrial origins respectively were valid only for klk correspondingly the use of differences between mid chain and long chain compound specific d n alkanes as a possible paleoclimatic indicator was feasible only for this lake hence our results emphasize the complex relationship between the chain length of lacustrine n alkanes and their actual origins and suggest that the correlation analysis of d n alkanes data for different chain length could be part of the possible evaluation method for the application of lacustrine compound specific d n alkanes data in paleoclimatic studies

sensitivity of climate to late cenozoic uplift in southern asia and the american west numerical experiments experiments with general circulation models with no mountains half mountains and full modern mountains show the sensitivity of atmospheric circulation patterns to progressive amounts of uplift the experiments were motivated by geologic evidence for large kilometer scale uplift in the late cenozoic in southern asia and the american west particularly within the last 10 m y in january the amplitude of the mid latitude upper tropospheric planetary waves increased with uplift and the low level winds were progressively blocked or diverted around the topographic features in july the progressive uplift caused monsoonlike circulations to develop in the vicinity of the colorado and tibetan plateaus atmospheric heating rates midtroposphere vertical motion and upper tropospheric planetary wave amplitudes varied approximately linearly with progressive uplift these results suggest that geologically recent kilometer scale uplift may have had climatic consequences comparable in magnitude and pattern to those of earlier stages of uplift comparison of the simulated climatic effects of uplift with the geologic evidence for late cenozoic climatic change especially for the last 10 m y is given in accompanying papers

δd values of individual n alkanes from terrestrial plants along a climatic gradient implications for the sedimentary biomarker record abstract the compound specific hydrogen isotope composition d of sedimentary n alkanes is increasingly used as a palaeoclimate proxy to explore the origin of the hydrogen isotope signal of n alkanes from higher terrestrial plant biomass in sedimentary organic matter of small lakes we have analysed the n alkane composition and d values of 31 plant biomass samples birch betula beech fagus oak quercus alder alnus hornbeam carpinus and myrtle myrtus as well as non stomata containing sphagnum cladonia and moss from 14 sites along a climatic gradient from northern finland to southern italy eleven of the sites were previously investigated for the n alkane d values in adjacent lake sediments and are compared to the leaf wax n alkane d values the distribution of terrestrial n alkanes in lake sediments was not found to be characteristic of the dominant vegetation around the lake evidently n alkane distributions within the same species at different sites were found to be variable these findings complicate the use of certain n alkane distributions in sediments as a palaeoenvironmental indicator d values of plant biomass n alkanes show a significant positive correlation with the precipitation d values biomass n alkane d values are in general less negative than the associated sedimentary n alkanes of terrestrial origin possibly due to the stronger evapotranspiration during the summer when sampling took place this suggests that n alkanes in leaves show seasonal variations and the sedimentary organic matter receives the lighter isotope signal of the autumn when most leaves are incorporated into the sediment the variability of the d values from non stomata containing plants is much higher than for broadleaf trees since stomata can regulate water loss through evapotranspiration the average chain length acl of n alkanes from deciduous tree leaves increases from north to south with increasing acl the hydrogen isotopic fractionation e between source water and n alkanes also increases our results prove that terrestrial n alkane d values record the d value of precipitation modified by the amount of isotope enrichment in the leaf water due to plant anatomy stomata vs no stomata and site specific meteorological conditions such as evapotranspiration relative humidity and soil moisture therefore terrestrial n alkanes in lake sediments can deliver information on changes in these parameters over geological timescales in lake sediments where aquatic n alkanes such as n c 17 record the lake water d value the isotopic difference between terrestrial and aquatic n alkanes could therefore be used to reconstruct changes in evapotranspiration

holocene hydrologic and vegetation developments in the orange river catchment south africa and their controls the summer rainfall zone srz in the south african interior experienced pronounced hydrological and vegetation changes during the holocene inferred to be driven mainly by shifts in atmospheric and

δ13c δ18o and deposition rate of tufa in xiangshui river sw china implications for land cover change caused by climate and human impact during the late holocene

high relief topography of the nima basin in central tibetan plateau during the mid cenozoic time abstract there remains inconsistence of uplift history of the tibetan plateau here we estimated paleoelevation of mid cenozoic nima basin located in central tibet using multi proxies they included meteoric water and vegetation isotope proxies based on hydrogen and carbon isotopic compositions d and 13c respectively of terrestrial plant wax lipid of n alkanes and temperature proxy derived from microbial membrane lipid of branched glycerol dialkyl glycerol tetraethers brgdgts lipid analysis on sedimentary rocks in the nima basin yielded 222 12 and 30 0 0 7 for d and 13c of n c29 alkane respectively and brgdgt derived mean annual air temperature maat of 21 5 3 1 c for the paleo basin using the sea level meteoric water 18o and miocene siwalik paleovegetation 13c as low elevation references values of d and 13c of n c29 alkane in this study suggested paleoelevations of 4546 m and 2800 m respectively whereas by using a subtropical sea surface temperature as a reference brgdgt derived maats suggested a paleoelevation of 893 m we believed that the three estimates reflect a high relief topography in the study basin during the mid cenozoic representing elevations of orographic barrier of southerly oceanic moisture basin catchment and basin lake level respectively this scenario implies a low elevation of the basin relative to the lhasa terrane located to the south during the mid cenozoic hence challenging the classical crustal thickening models assuming a simple crustal thickening uplift relationship

effect of lake evaporation on δd values of lacustrine n alkanes a comparison of nam co tibetan plateau and holzmaar germany compound specific hydrogen isotope ratio values of lacustrine n alkanes from two contrasting ecosystems the semiarid to arid nam co central tibet and the humid holzmaar germany were compared in order to assess whether or not these environmental conditions are recorded in the isotopic signatures of biomarkers increased evaporation of lake water at nam co is recorded by the n alkanes of aquatic origin hence isotopic enrichment results in a di erence between terrestrial and aquatic n alkanes in the opposite direction 68 from that known for humid climate conditions 30 predominating at holzmaar based on this isotopic di erence between terrestrial and aquatic n alkanes evaporation to inflow ratio e i values were estimated and suggest that the isotopic di erence is indicative of the general hydroclimatic characteristics of a lake system moreover the comparison with e i values calculated with actual stable water isotope data showed that the dd values of aquatic and terrestrial lacustrine n alkanes serve as a proxy for the relative isotopic di erences between lake and inflow waters and can be used to assess the proportion of water undergoing evaporation relative to the inflow and thus to reconstruct the lake water balance in the past 2008 published by elsevier ltd

age and paleoclimatic implications of the bet shean travertines abstract from 41 000 to over 22 000 yr b p a massive and areally extensive spring travertine was deposited in the bet shean valley israel this travertine is coeval with the ami az member of the lisan formation which represents a high lake stand the travertine deposition is contemporaneous with a more active hydrologic regime associated with wetter conditions in the arid zones of the southern levant adjacent to southern israel these wetter conditions facilitated formation of a widespread spring tufa and also enhanced the water levels of lake lisan

δ18o and δd of streamwaters across the himalaya and tibetan plateau implications for moisture sources and paleoelevation reconstructions abstract this study presents new 18o and d data from 191 streams across the himalaya and tibetan plateau to better constrain the spatial variability of stable isotopes in modern precipitation over this region moisture penetrating into the southeastern tibetan plateau is predominantly derived from monsoonal airmasses originating from the bay of bengal and transported into the eastern himalayan syntaxis along the brahmaputra river progressive rainout during orographic lifting and cooling results in clear relationships between 18o and d and catchment hypsometric elevation on the plateau margin however monsoonal derived moisture is progressively mixed with central asian airmasses in more western and northern parts of the tibetan plateau as a result predicted isotope elevation relationships that are based on empirical lapse rates or thermodynamic models of the isotopic evolution of an airmass produce large 1 3 km misfits between measured and predicted catchment elevations for much of the tibetan plateau including some areas directly north of the central himalayan crest this suggests that changes in the 18o or d of paleoprecipitation on the central and southwestern tibetan plateau may reflect surface uplift along moisture transport pathways or changes in the penetration of monsoonally derived moisture rather than regional surface uplift histories

last glacial warm events on mount hermon the southern extension of the alpine karst range of the east mediterranean abstract this study focuses on warm last glacial episodes in the southernmost extension of the alpine karst range of the eastern mediterranean levant region through the study speleothems in mizpe shelagim cave located in mt hermon the alpine karst range extends from turkey through syria and lebanon reaching its southern limit in mt hermon at an elevation of more than 2000 m under present day conditions southern mt hermon receives 1000 2000 mm precipitation mostly as snow that originates in the eastern mediterranean sea speleothems deposition in this high altitude region was continuous during interglacials but during the last glacial growth only occurred when average annual temperatures exceeded 3 c as inferred from the study of speleothem fluid inclusions warming episodes occurred at 65 ka 56 ka 54 5 ka 52 5 51 ka 49 ka 42 ka and 36 ka and are coincident with maximum insolation at 65 n the main depositional period from 56 ka to 51 ka coincides with dansgaard oeschger interstadial 15 and 14 and warming in the northeastern basin of the mediterranean sea warming in the southern alpine karst range of the eastern mediterranean was manifested by vegetation development together with significant snow melting that resulted in the drainage of large amount of water to the dead sea rift valley

compound specific δd values of long chain n alkanes derived from terrestrial higher plants are indicative of the δd of meteoric waters evidence from surface soils in eastern china the stable carbon and hydrogen isotope composition of higher plant derived long chain n alkanes 13cn alkanes and dn alkanes from 45 surface soil samples within well characterized vegetation zones from eastern china 18 n 50 n are reported the weighted average dn alkanes value for n c27 n c29 and n c31 in the samples and the annual average d of meteoric water recorded at 12 weather stations proximal to the sampling sites show similar spatial variations the d of n alkanes shows a gradual depletion in value with increasing latitude the results demonstrate that on a large spatial scale the d values of long chain n alkanes derived from higher plants have the potential to record the d of meteoric water although many other factors can also influence the isotope values there appears to be no apparent relationship between the d of the n alkanes extracted from the surface soil and the overlying vegetation type i e forest grassland or c3 c4 composition therefore palaeoenvironmental studies utilizing dn alkanes from higher plant derived material in geological samples have the potential to provide additional information with regard to the past hydrological cycle