greenland flow variability from ice sheet wide velocity mapping using radarsat synthetic aperture radar data we have mapped the flow velocity over much of the greenland ice sheet for the winters of 2000 01 and 2005 06 these maps provide a detailed view of the ice sheet flow including that of the hundreds of glaciers draining the interior the focused patterns of flow at the coast suggest a strong influence of bedrock topography differences between our two maps confirm numerous early observations of accelerated outlet glacier flow as well as revealing previously unrecognized changes the overall pattern is one of speed up accompanied by terminus retreat but there are also several instances of surge behavior and a few cases of glacier slowdown comprehensive mappings such as these at regular intervals provide an important new observational capability for understanding ice sheet variability

middle to late holocene decreased fluvial aggradation and widespread peat initiation in the ishikari lowland northern japan this study investigated the influence of sea level and climate changes on the decreased fluvial aggradation and subsequent widespread peat initiation in the middle to late holocene in the ishikari lowland which is a coastal floodplain formed in response to the postglacial sea level change by introducing a new approach to separately evaluate the rates of organic and clastic sediment input we demonstrated that the peat began to form when the fluvial sedimentation rate was significantly decreased less than 0 6 mm yr while plant macrofossil analysis suggested that lowering of water level is also important to the peat initiation such changes in sedimentary environment may be associated with the abrupt abandonment of crevasse splays the concentrated ages of the peat initiation around 5600 5000 4600 4300 and 4100 3600 cal bp suggest that an allogenic control promoted the abandonment of crevasse splays and different onset ages can be explained by different fluvial responses of the ishikari river and i

vegetation zones and diagnostic pollen profiles of a coastal peat swamp bocas del toro panama abstract a survey of the dominant vegetative cover of a large domed coastal swamp near changuinola in the province of bocas del toro panama has been undertaken as an initial step in reconstructing the holocene history of peat accumulation on this coast seven phasic communities of peat forming vegetation are defined and mapped 1 rhizophora mangle mangrove swamp 2 mixed back mangrove swamp 3 raphia taedigera palm swamp 4 mixed forest swamp 5 campnosperma panamensis forest swamp 6 sawgrass stunted forest swamp 7 myrica cyrilla bog plain pollen extracted from surface peat samples and collected from dominant vegetation at representative sites is used to prepare a pollen profile of each phasic community these profiles are then compared to pollen distribution in 2 peat cores one from the deep central part of the deposit and the second from a site near the marine margin in order to construct a history by floral succession of the 4000 year evolution of the deposit the changuinola mire originated as freshwater palm and hardwood forest swamps that developed in close proximity to both the changuinola river mouth probably behind a barrier bar and freshwater lagoon system adjacent to a low energy mangrove dominated bay the early swamp was likely drained to the southeast by brackish blackwater creeks much as it is today and formerly extended considerably farther in the direction of almirante bay the palm swamp was succeeded by hardwood forest swamp dominated by a very limited number of specialized species only one of which campnosperma panamensis is prone to forming monospecific stands increasing accumulation of woody peat promoted by the everwet climate impeded drainage of the mire leading to doming increased oligotrophy and establishment of bog plain conditions in a manner similar to that described by the anderson model of succession in the coastal swamps of malaysia and indonesia development of the changuinola mire did not require the initial mangrove phase which is common to the peat swamps of southeast asia as the palm raphia taedigera is able to colonise and institute peat accumulation in a variety of freshwater and brackish environments

a new ice thickness and bed data set for the greenland ice sheet 1 measurement data reduction and errors ice thickness data collected between 1993 and 1999 using a coherent ice penetrating radar system developed at the university of kansas have been combined with data collected by the technical university of denmark in the 1970s to produce a new ice thickness grid for greenland crossover analysis was used to assess the relative accuracy of the two data sets and they were weighted accordingly and interpolated onto a regular 5 km spacing grid using a kriging interpolation procedure a high resolution land ice mask was used to help constrain the interpolation of the ice thickness data near the ice sheet margins where in the past the relative errors have been largest the ice thickness grid was combined with a new digital elevation model of the ice sheet and surrounding rock outcrops to produce a new bed elevation data set for the whole of greenland the ice thickness grid was compared with the currently available data set differences in the center of the ice sheet where the ice is thickest were of the order of a few percent near the margins however large differences of as much as a factor of 10 were found the total volume of ice contained in the ice sheet was reestimated and found to have a value of 2 93 x 10 6 km 3 the ice thickness grid was used to calculate the spatial pattern of gravitational driving stress over the ice sheet anomalous patterns of stress were found in areas that appeared to be associated with areas of rapid flow

opaline and al si phytoliths from a tropical mire system of west malaysia abundance habit elemental composition preservation and significance abundant and unique opaline and al si phytoliths and opaline bioliths have been discovered in holocene peat deposits of tropical tasek bera in peninsular malaysia these are secreted mainly by plants higher plants and algae and incorporated in the sediment cycle during the rapid biomass turnover many wetland plants have entire skeletons secreted the study shows that differing plant parts of same species as well as same parts of differing plant species incorporate different amounts of elements whilst deciduous trees of the swamp forest have phytoliths enriched in al most phytoliths of palms sedges and grasses of the littoral swamp are composed of opaline silica incorporation of al and many other elements into relatively stable phytoliths is the result of high evapotranspiration rate and ample plant available elements and can serve to detoxify the soil solution because of the abundance of such opaline and al si structures spongillid and algal remains in acid peat accumulating environments tropical peatlands represent repositories of si and al which together with variable amounts of other elements could provide the prime material for silicate neoformation during later diagenetic processes neoformation of minerals from bioliths would explain the scarcity of biogenic remains in carboniferous and tertiary coal deposits furthermore incorporation of major elements in phytoliths may limit the rate of leaching of these elements in an environment where biomass turnover is rapid thus reducing the loss of nutrients and other plant essential elements most nutrients of tropical peats are recycled by plants within the top 150 cm and an upward migration of plant essential elements such as mg ca or p but also of si and al occurs during peat accumulation such elemental cycling strongly influences the geochemical composition of the peats during mire evolution utilizing al for normalization of major and minor elements of tropical peats for paleoclimatic and paleodepositional analyses may thus result in incorrect interpretations

biota and palaeoenvironment of a high middle latitude late triassic peat forming ecosystem from hopen svalbard archipelago a siliceous permineralized peat block recovered from hopen in the svalbard archipelago hosts a low diversity late triassic flora dominated by autochthonous roots and stems of bennettitaleans and lycophytes and parautochthonous leaves sporangia spores and pollen from a small range of pteridophytes and gymnosperms some parenchymatous bennettitalean root cells show interactions with chytrid fungi and bacteria the remains of other fungi and fungi like organisms are dispersed within the peat s detrital matrix cavities excavated through some roots and compacted detritus contain abundant coprolites probably derived from sapro xylophagous oribatid mites although no body fossils have yet been identified sparse larger coprolites containing leaf fragments attest to the presence of invertebrate folivores in the ancient ecosystem the low diversity flora relatively few trophic levels and simple nutritional web together with sedimentological aspects of the host formation and the peat structure collectively favour accumulation of the organic mass as a fibric root dominated peat within a temperate high middle latitude well aerated mire

sulfur in the changuinola peat deposit panama as an indicator of d the environments of deposition of peat and coal abstract the sulfur s content of coal is often used to infer aspects of paleoclimate trophic state and proximity to marine influence of the mire in which it was deposited in this study the s content of peat in a large back barrier mire complex on the caribbean coast of panama is related to climatic biological and tectonic factors of the depositional environment earthquake generated subsidence is greatest to the southeast leading to drowning of the deposit beneath almirante bay and 40 of the peat is now below sea level coastal mangrove peats with moderately high s content 1 5 wt s and high salinity 1 0 wt dominate the eastern margin and extend beneath the salt water and shallow marine sediments of the adjoining bay marine influence extends only a short distance onsho e except in the vicinity of brackish blackwater creeks that drain the swamp peats associated with these tidal channels are low in salinity 1 0 wt and very high in s 5 to 14 wt s apparently the result of a biogeochemical chain of s reactions leading to the concentration of c s sulfides the western part of the deposit is domed and the vegetation and the peat are concentrically zoned stunted sawgrass dominated vegetation that produces fibric very low s 0 25 wt s peat occupies the central bog plain around the bog plain mixed forest and palm forest swamps produce dense hemic and fine heroic peat with higher s content 0 250 5 wt s the s content is in proportion to the degree of humification of the peat and both are independent of the ph of the groundwater the distribution of forms of organic and inorganic sulfur in the tropical peats are found to be comparable to published values for temperate and subtropical peats despite differences in vegetation and climate the distribution of high sulfur peats in the eastern part of the deposit and low sulfur peats in the western part and the se nw transgression parallel to the trend of the coastline reflects the regional structural trend of coseismic subsidence greatest to the southeast

cap carbonates and neoproterozoic glacigenic successions from the kimberley region north west australia the term cap carbonate is commonly used to describe carbonate units associated with glacigenic deposits in neoproterozoic successions attempts to use carbonate units as stratigraphic markers have been counfounded by inconsistent identification of cap carbonates and a somewhat broad use of the term systematic sedimentological and geochemical analysis of carbonate rocks mostly dolomite associated with glacigenic deposits from the neoproterozoic succession of the kimberley region north western australia shows that it is possible to characterize such units by their specific mineralogical sedimentological petrographic geochemical and stratigraphic features hence it is possible to differentiate true cap carbonates from other carbonate units that are associated with glacigenic deposits in the kimberley successions two broad carbonate types are identified that reflect two stratigraphically distinct depositional realms carbonate rocks from the egan formation and boonall dolomite the youngest carbonate units in the succession are characterized by sedimentary components and features that are consistent with deposition on shallow platforms or shelves analogous to phanerozoic warm water carbonate platform deposits in contrast dolomite from the walsh landrigan and moonlight valley tillites preserves a suite of sedimentary and geochemical characteristics that are distinctly different from phanerozoic like carbonate rocks they are thin ca 6 m laterally persistent units of thinly laminated dolomicrite dolomicrospar recording 13c fluctuations from 1 to 5 these latter features are consistent with a marinoan style cap carbonate rock described from other neoproterozoic successions the similarity and broad distribution of these rocks in australia when considered within the context of genetic models suggesting a global oceanographic atmospheric event support their use as a lithostratigraphic marker horizon for the start of the ediacaran period at ca 635 ma

coherent radar ice thickness measurements over the greenland ice sheet we developed two 150 mhz coherent radar depth sounders for ice thickness measurements over the greenland ice sheet we developed one of these using connectorized components and the other using radio frequency integrated circuits rfics both systems are designed to use pulse compression techniques and coherent integration to obtain the high sensitivity required to measure the thickness of more than 4 km of cold ice we used these systems to collect radar data over the interior and margins of the ice sheet and several outlet glaciers we operated both radar systems on the nasa p 3b aircraft equipped with gps receivers radar data are tagged with gps derived location information and are collected in conjunction with laser altimeter measurements we have reduced all data collected since 1993 and derived ice thickness along all flight lines flown in support of program for regional climate assessment parca investigations and the north greenland ice core project radar echograms and derived ice thickness data are placed on a server at the university of kansas http tornado rsl ukans edu greenlanddata htm for easy access by the scientific community we obtained good ice thickness information with an accuracy of 10 m over 90 of the flight lines flown as a part of the parca initiative in this paper we provide a brief description of the system along with samples of data over the interior along the 2000 m contour line in the south and from a few selected outlet glaciers

the stratigraphy and fire history of the kutai peatlands kalimantan indonesia abstract the equatorial peatlands of the kutai lowland of eastern kalimantan are generally 4 10 m in thickness but some sections exceed 16 m in depth the deposition of peat commenced about 8000 yrs ago after shallow flooding of the basin by the mahakam river the earliest vegetation is a pandanus swamp which grades upwards to swamp forest dominated by dipterocarps the peatland has expanded laterally and rivers have maintained narrow levee channel tracks through the swamp which has grown vertically in balance with river accretion historical fires are associated with extreme el nino years of drought but human agency is important the fires of 1982 1983 and 1997 1998 burnt up to 85 of the vegetation on the peatland although charcoal analyses show that fire has occurred throughout the history of the peatland it is rare in forests remote from rivers until the last 3000 years and only common within the last millennium fires are earlier and more frequent in sites accessible from waterways and floodplains have been widely burnt down to water table or below forming extensive lakes

greenland ice sheet surface properties and ice dynamics from ers 1 sar imagery c band synthetic aperture radar sar imagery from the european space agency s ers 1 satellite reveals the basic zonation of the surface of the greenland ice sheet the zones have backscatter signatures related to the structure of the snowpack which varies with the balance of accumulation and melt at various elevations the boundaries of zones can be accurately located with the use of this high resolution imagery the images also reveal a large flow feature in northeast greenland that is similar to ice streams in antarctica and may play a major role in the discharge of ice from the ice sheet

characterization and quantification of inorganic constituents of tropical peats and organic rich deposits from tasek bera peninsular malaysia implications for coals abstract since the carboniferous tropical latitudes have been the site of formation of many economic coal deposits most of which have a restricted range of mineralogical composition as a result of their depositional environment climatic conditions and diagenesis mineralogical and microscopic investigations of tropical peats from tasek bera peninsular malaysia were performed in order to better understand some of these factors controlling the nature distribution and association of inorganic matter in peat forming environments distribution and nature of the inorganic fraction of peat deposits give insight into the weathering conditions and detrital input into the mire system because the inorganic composition of peat deposits is determined by plant communities height of water table and climate the results of the quantitative and qualitative analysis can be used to reconstruct palaeoclimatic conditions tasek bera is a peat accumulating basin in humid tropical malaysia with organic deposits of low to high ash yield and thus representative of many ancient peat forming environments clay minerals dominate the mineralogical composition of the peat and organic rich sediments while quartz and clays dominate the underlying siliciclastic deposits kaolinite is the most abundant clay mineral in the organic deposits with minor amounts of illite and vermiculite particle size analyses indicate that 50 of the inorganic detrital fraction is 75 of the ash constituents as a consequence the vegetational communities make an important contribution to the inorganic and overall ash composition of peats and coals the ash content of the often inundated peat consists on average of 10 opaline silica from diatoms and sponge spicules while the ash of the top deposits may have up to 50 biogenic silica hence al and si hydroxides and the opaline silica from diatoms and sponges represent a large repository of al and si which may form the basis of mineral transformation neoformation and alteration processes during coalification of the peat deposits as a result most coal deposits from paleotropical environments are anticipated to have little to no biogenic inorganic material but high amounts of secondary clays such as kaolinite detrital kaolinite resilisified kaolinite or desilisified gibbsite or illite and various amounts of detrital and authigenetic quartz

a new ice thickness and bed data set for the greenland ice sheet 2 relationship between dynamics and basal topography new data sets of bed and surface elevation have been combined with balance velocities bed topography and radar reflectivity to investigate the relationship between ice flow and bed conditions it has been found that the bed topography affects the local driving stresses and initiates the onset of streaming flow in specific areas where there are large undulations this onset region only appears significantly inland in three areas the northeast greenland ice stream kangerdlugssuaq gletscher and a region in the southwest associated with abnormally low driving stresses and an apparently unnamed but active glacier bed reflectance values below the northeast ice stream suggest that basal melting could be occurring along its length and it seems likely therefore that the enhanced flow observed inland from the onset of streaming may be due in part to basal sliding

development and carbon sequestration of tropical peat domes in south east asia links to post glacial sea level changes and holocene climate variability abstract tropical peatlands of se asia represent a significant terrestrial carbon reservoir of an estimated 65 gt c in this paper we present a comprehensive data synthesis of radiocarbon dated peat profiles and 31 basal dates of ombrogenous peat domes from the lowlands of peninsular malaysia sumatra and borneo and integrate our peatland data with records of past sea level and climate change in the region based on their developmental features three peat dome regions were distinguished inland central kalimantan borneo kutai basin borneo and coastal areas across the entire region with the onset of the holocene the first peat domes developed in central kalimantan as a response to rapid post glacial sea level rise over the sunda shelf and intensification of the asian monsoon peat accumulation rates in central kalimantan strongly declined after 8500 cal bp in close relation to the lowering rate of the sea level rise and possibly influenced by the regional impact of the 8 2 ka event peat growth in central kalimantan apparently ceased during the late holocene in association with amplified el nino activity as exemplified by several truncated peat profiles peat domes from the kutai basin are all younger than 8300 cal bp peat formation and rates of peat accumulation were driven by accretion rates of the mahakam river and seemingly independent of climate most coastal peat domes the largest expanse of se asian peatlands initiated between 7000 and 4000 cal bp as a consequence of a holocene maximum in regional rainfall and the stabilisation and subsequent regression of the sea level these boundary conditions induced the highest rates of peat accumulation of coastal peat domes the late holocene sea level regression led to extensive new land availability that allowed for continued coastal peat dome formation until the present the time weighted mean holocene peat accumulation rate is 0 54 mm yr 1 for central kalimantan 1 89 mm yr 1 for kutai and 1 77 mm yr 1 for coastal domes of sumatra and borneo the mean holocene carbon sequestration rates amount to 31 3 g c m 2 yr 1 for central kalimantan and 77 0 g c m 2 yr 1 for coastal sites which makes coastal peat domes of south east asia the spatially most efficient terrestrial ecosystem in terms of long term carbon sequestration

a new bedrock and surface elevation dataset for modelling the greenland ice sheet a new digital elevation model of the surface of the greenland ice sheet and surrounding rock outcrops has been produced from a comprehensive suite of satellite and airborne remote sensing and cartographic data sets the surface model has been regridded to a resolution of 5 km and combined with a new ice thickness grid derived from ice penetrating radar data collected in the 1970s and 1990s a further data set the international bathymetric chart of the arctic ocean was used to extend the bed elevations to include the continental shelf the new bed topography was compared with a previous version used for ice sheet modelling near the margins of the ice sheet and in particular in the vicinity of small scale features associated with outlet glaciers and rapid ice motion significant differences were noted this was highlighted by a detailed comparison of the bed topography around the north east greenland ice stream

seafloor precipitates and c isotope stratigraphy from the neoproterozoic scout mountain member of the pocatello formation southeast idaho implications for neoproterozoic earth system behavior abstract macroscopic seafloor precipitated crystal fans are rare in post paleoproterozoic strata but they are more common in the unusual carbonates that cap certain neoproterozoic glacial strata the uppermost carbonate and marble unit of the scout mountain member of the neoproterozoic pocatello formation younger than 667 5 ma contains seafloor fans records negative 13 c values and lies within a transgressive sequence all features consistent with such post glacial carbonate units it does not however rest directly upon a known glaciogenic deposit or sequence boundary instead it occurs within a cyclic upward fining succession that overlies an erosional contact on the pink dolostone post glacial carbonate atop the late sturtian scout mountain member diamictites it is possible that the carbonate unit in question is a cap carbonate and thus requires recognition of an additional glaciation recorded in the pocatello formation alternatively it may imply that means independent of glaciation such as overturn of an anoxic ocean foster the deposition of cap like carbonates independent of post glacial processes thus neoproterozoic carbonate units with unusual lithofacies and negative carbon isotope values need not indicate the aftermath of low latitude glaciation additionally the radiometrically calibrated 13 c record of the pocatello formation demonstrates that the interval from 700 to 580 ma has more variation than previous compilations would suggest

holocene floodplain evolution in the shiribeshi toshibetsu river lowland northern japan abstract the influence of sea level and climate changes on the evolution of coastal floodplains is an important problem in fluvial geomorphology and geology however few studies have constructed detailed chronologies of floodplain evolution and the influence of sea level and climate changes at submillennial time scales is not clear this study investigated the holocene evolution of the floodplain in the shiribeshi toshibetsu river lowland hokkaido northern japan based on 13 auger cores 15 radiocarbon ages and 2 cross sections made using existing columnar sections in the study area peat beds 3 6 m thick in the uppermost holocene sediments are underlain by fluvial sediment that mainly consists of sand beds resulting from crevassing or progradational avulsion age elevation plots of the bases of these peat beds suggest that fluvial aggradation was continuous until peat formation began which in turn suggests that peat beds began to form with the cessation of fluvial deposition the chronology of floodplain sediments based on radiocarbon ages indicates that peatlands began to develop locally before ca 6500 cal bp and became moderately widespread before 5600 cal bp peatlands then became more extensive after two periods of rapid expansion during ca 5300 5000 and 4100 3900 cal bp comparison with sea level and regional climate changes suggests that the initiation of these peat beds before 5600 cal bp was associated with the deceleration of sea level rise at ca 7000 cal bp the two later periods of peatland expansion may have been strongly influenced by reduced fluvial activity due to decreased precipitation from a weakened east asian summer monsoon this interpretation suggests that floodplain evolution was controlled by sea level and climate changes and that the response to climate change occurred at submillennial time scales a comparison with the ishikari lowland on hokkaido showed that the two floodplains have slightly different histories possibly because of differences in internal characteristics of the fluvial systems such as the number and size of tributary rivers water discharge and sediment supply although their responses to sea level and climate changes were similar the fluvial response to sea level and climate changes revealed in this study has implications for studies of the holocene evolution of other coastal floodplains

the age palaeoclimate palaeovegetation coal seam architecture mire types paleodepositional environments and thermal maturity of syn collision paralic coal from mukah sarawak malaysia abstract the mukah coal accumulated in the balingian formation where the time stratigraphic position is poorly defined by fauna though a probable late miocene age has always been assigned to this formation samples collected in the present study that yielded an abundance of casuarina pollen associated with occurrences of dacrydium stenochlaena palustris florschuetzia levipoli and also stenochlaena areolaris spores compare closely to zone pr9 of the palynological zonation of the malay basin and can be tied to depositional sequences of malay basin seismic sequences i2000 i3000 indicating an early miocene age for the studied coal the early miocene age shows that the mukah coal was formed during the collision between luconia block dangerous grounds with the borneo that lasted from late eocene to late early miocene the rapid increase of deposition base level caused by the collision is clearly reflected by the architecture of the mukah coal seams that were generally thin and also by the reverse order of the paleo peat bodies the studied coal samples contained large amounts of detrohuminite without the enrichment of liptinite group macerals usually explained by the dominance of herbaceous plants in the paleomires however the pollen assemblages recovered in the present study provide no support for a herbaceous swamp instead the peats were likely formed mainly from forest vegetation based on the recovery of dominant arboreal pollen assemblages in the present study palynomorph assemblages recovered in the present study with abundance of casuarina pollen associated with common occurrences of dacrydium strongly suggest kerangas vegetation and kerapah type peat swamps indicating a very wet climate the occurrence of rattan and pandanus pollens shows that the kerapah type peat swamps were locally bordered by rattan and pandanus swamps this shows that the prevailing use of coal petrography to discern the type of vegetation that was present in the peat forming mires may lead to wrong conclusions therefore a multi disciplinary approach must be applied for a more accurate and reliable spatial interpretation of the type of vegetation that was present in the peat forming mires consistent with the low sulphur content evidence from the palynomorph assemblages recovered from the coal seams shows that the coal forming peat was deposited in freshwater mires with little or no marine influence despite the fact that the accumulation of the mukah coal forming peat took place within a coastal plain setting moreover the fauna present in the host rock formation also suggested a brackish water environment of deposition

bed roughness beneath the greenland ice sheet the roughness of the bed beneath ice streams exerts an important control on their dynamics here the first in depth analysis of roughness beneath the greenland ice sheet is presented much of the interior is underlain by a smooth bed while the margins are much rougher this is particularly pronounced in the east where more mountainous topography dominates and fast flow features are laterally constrained in deep narrow valleys in contrast fast flow in the west is much less laterally constrained and areas of high roughness are less extensive and pronounced it is proposed that there is a major geological control on the distribution of bed variability since a significant thrust fault coincides approximately with the boundary between rough terrain in the east and the smooth central region furthermore there is an abrupt change in roughness approximately coinciding with the crossing of this fault line this suggests a limiting factor on the extent of fast flow in the east which is lacking in the west the size of many glaciers draining greenland makes their local bed conditions difficult to determine with great confidence however the much larger petermann glacier lies in a deep trough characterized by a smooth bed that extends some distance into the ice sheet the smooth bed may be due to deformable marine sediments which facilitate faster flow although smoothing could also result from ice dynamics and subglacial erosion that the smooth bed of petermann glacier extends some considerable distance raises concerns about the possible stability of this feature and perhaps others in greenland too

steady state characteristics of the greenland ice sheet under different climates the greenland ice sheet is modelled to simulate its extent and volume in warmer climates and also to find out whether the ice sheet would re form on theice free bedrock under present climatic conditions the ice sheet model is a three dimensional thermo mechanical model with a fine resolution grid thebedrock surface beneath the ice sheet was mapped using radio echo sounding measurements by the electromagnetic institute copenhagen the modelexperiments show that increased temperature will result in ice margin retreat but the ice sheet is relatively stable it takes a rather high temperature rise of atleast 6ic for the ice sheet to disappear completely which indicates that the ice sheet probably survived the last interglacial also it appears that the greenlandice sheet is not a mere relict ice mass from a previously colder climate but that the ice sheet will still re form on the bare bedrock under the present or evenslightly warmer climatic conditions

rates of southeast greenland ice volume loss from combined icesat and aster observations 1 repeat satellite laser altimetry is critical for observing the rapidly changing mass balance of the greenland ice sheet however sparse sampling and high surface slopes over rapidly thinning coastal outlet glaciers may result in underestimation of mass loss here we supplement icesat derived surface elevation changes with differenced aster digital elevation models of outlet glaciers in southeastern greenland the region with the largest concentrated change in outlet glacier mass loss we estimate a 2002 2005 regional volume loss rate of 108 km3 yr our results are consistent with drainage scale grace and mass budget estimates when differences in observation periods are taken into account the two largest glaciers kangerdlugssuaq and helheim account for only 28 of the mass loss illustrating the combined importance of smaller glaciers and the need for complete observational coverage additionally we find that rapid concentrated thinning within the outlets represents a small contribution to the total volume change compared to dispersed inland thinning

observation and analysis of ice flow in the largest greenland ice stream we have applied satellite radar interferometry methods to map the velocity field of the recently discovered northeast greenland ice stream we have used these data in conjunction with ice thickness and accumulation data to determine that the ice stream is in balance within the measurement errors we used control methods to invert a finite element model of ice sheet flow constrained by the data to infer the ice stream s basal shear stress distribution our results reveal that flow in a section of the downstream end has much in common with the streaming flow of the ross ice streams of west antarctica e g a weak bed and fast flow in the presence of low driving stresses for several hundred kilometers along the middle of the ice stream the basal shear stress balances the driving stress in the upstream area where the ice stream is first visible in the velocity data the bed appears to be weak which may contribute to the initiation of the ice stream

a new high resolution digital elevation model of greenland fully validated with airborne laser altimeter data a new digital elevation model of the greenland ice sheet and surrounding rock outcrops has been produced at 1 km postings from a comprehensive suite of satellite remote sensing and cartographic data sets height data over the ice sheet were mainly from ers 1 and geosat radar altimetry these data were corrected for a slope dependent bias that had been identified in a previous study the radar altimetry was supplemented with stereophotogrammetric data sets synthetic aperture radar interferometry and digitized cartographic maps over regions of bare rock and where gaps in the satellite altimeter coverage existed the data were interpolated onto a regular grid with a spacing of 1 km the accuracy of the resultant digital elevation model over the ice sheet was assessed using independent and spatially extensive measurements from an airborne laser altimeter that had an accuracy of between 10 and 12 cm in a comparison with the laser altimetry the digital elevation model was found to have a slope dependent accuracy ranging from 1 04 1 98 m to 0 06 14 33 m over the ice sheet for a slope range of 0 0 1 0 the mean accuracy over the whole ice sheet was 0 33 6 97 m over the bare rock areas the accuracy ranged from 20 to 200 m dependent on the data source available the new digital elevation model was used as an input data set for a positive degree day model of ablation the new elevation model was found to reduce ablation by only 2 compared with using an older 2 5 km resolution model which suggests that resolution induced errors in estimating ablation are no longer important

chemostratigraphy of predominantly siliciclastic neoproterozoic successions a case study of the pocatello formation and lower brigham group idaho usa abstract isotopic chemostratigraphy has proven successful in the correlation of carbonate rich neoproterozoic successions in successions dominated by siliciclastic rocks chemostratigraphy can be problematic but if thin carbonates punctuate siliciclastic strata useful isotopic data may be obtained the upper pocatello formation and lower brigham group of southeastern idaho provide an opportunity to assess the potential and limitations of isotopic chemostratigraphy in overwhelmingly siliciclastic successions the 5000 m thick succession consists predominantly of siliciclastic lithologies with only three intervals that contain thin intercalated carbonates its depositional age is only broadly constrained by existing biostratigraphic sequence stratigraphic and geochronometric data the lowermost carbonates include a cap dolomite atop diamictites and volcanic rocks of the pocatello formation the delta 13c values of these carbonates are distintly negative 5 to 3 similar to carbonates that overlie neoproterozoic glaciogenic rocks worldwide stratigraphically higher carbonates record a major positive delta 13c excursion to values as high as 8 8 within the carbonate member of the caddy canyon quartzite the magnitude of this excusion is consistent with post sturtian secular variation recorded elsewhere in the north american cordillera australia svalbard brazil and nambia and exceeds the magnitude of any post varanger delta 13c excursion documented to date in most samples sr isotopic abundances have been altered by diagenesis and greenschist facies metamorphism but a least altered value of approximately 0 7076 supports a post sturtian and pre marinoan varanger age for upper pocatello and lower brigham rocks that lie above the pocatello diamictite thus even though available chemostratigraphic data are limited they corroborate correlations of pocatello formation diamictites and overlying units with sturtian glaciogenic rocks and immediately post sturtian successions in western north america and elsewhere

bedrock controls on subglacial landform distribution and geomorphological processes evidence from the late devensian irish sea ice stream abstract ice streams play an important role as regulators of the behaviour of modern ice sheets taking the form of corridors of fast flowing ice similar zones of fast moving ice have also been recognised draining the margins of the late devensian british and irish ice sheet although the geomorphological and sedimentary signatures of palaeo ice streams have received significant attention allowing the identification of these former ice streams the influence of bedrock geology on the processes occurring beneath these palaeo ice streams is less well understood even though subglacial geology has been shown to control the location ice streams within the west antarctic ice steam this paper highlights the role played by bedrock geology on landform distribution beneath a much older ice stream the late devensian irish sea ice stream the spatial relationships displayed between subglacial landforms and bedrock geology are described from anglesey northwest wales and the rhins of galloway southwest scotland both sites occur close to the eastern margin of this irish sea ice stream a link has been established between landform morphology and distribution and the disposition of the main tectonostratigraphical units within the bedrock changes in landform morphology are shown to have been locally controlled by large scale faults and or major lithological boundaries with less durable bedrock lithologies controlling the location and lateral extent of relatively faster flowing portions of the ice stream

vegetation development in an amazonian peatland recent investigations of wetlands in western amazonia have revealed the presence of extensive peat deposits up to 7 5 m thick developing under a variety of vegetation types we report the first attempt to establish the long term centennial to millennial scale vegetation history of one of these peatland sites quistococha a palm swamp close to iquitos in northern peru pollen and sedimentological analyses show that peat formation began at the core site under sedge fen or floating mat vegetation c 2200 calendar years before present cal yr bp a seasonally flooded woodland developed c 1880 cal yr bp the permanently waterlogged palm swamp which persists today began to form c 1000 cal yr bp with the present vegetation community established by c 400 years ago the vegetation at this site has undergone continuous change throughout the period of peat formation with several abrupt transitions and reversals and repetitions in the apparent trajectory of change the pollen data combined with sedimentary evidence suggest that the dominant control on ecosystem functioning and development is the flooding regime there appears to have been a decrease in fluvial influence over time there is no clear evidence of direct climatic or anthropogenic influence although we cannot rule out the possibility of climatically driven hydrological changes our results caution against adopting a simple model of peatland vegetation succession in this region

peat or no peat why do the rajang and mahakam deltas differ abstract coastal and deltaic holocene peat accumulations around the equatorial island of borneo southeast asia have served as models for economic coal bearing sequences in the stratigraphic record although climatic conditions vegetational communities and sedimentary regimes are comparable peat accumulations are not found on both the western and eastern sides of the island the rajang river delta and coastal plain sarawak east malaysia are covered in areally extensive thick peat deposits that have attained at least a thickness of 13 m in ombrogenous peat domes marudi baram river peat swamp biomass began to accumulate over pleistocene podzols when sea level stabilized 7 5 ka and delta progradation was initiated the mahakam river delta and coastal plain east kalimantan indonesia also began progradation at this time but there is no evidence in any part of the coastal region for peat accumulation rather poorly developed organic rich gleysols occur throughout the delta plain both the rajang river and mahakam river deltas are tidally influenced fine grained systems with a sediment provenance in the central massif sediment transported through the rajang river delta differs in that as much as 60 of the clay minerals deposited in the system are mixed layer i s and expandable k e clays that act to restrict pore water flow in the tidal and overbank deposits that comprise the delta plain these result in the development of an aquiclude above which paludal conditions develop promoting accumulation of organic matter in contrast there is a low proportion of mixed layer and expandable clays transported in the mahakam river system this precludes the development of a stilted water table within the delta allowing for organic matter recycling without peat accumulation the presence of a high proportion of expandable clay minerals on the western side of borneo is a reflection of the weathering and eroding source rocks on this side of the central borneo massif

problems in applying preservation facies and sequence models to sinian neoproterozoic glacial sequences in australia and asia abstract the sinian 800 530 ma is an extraordinary period of earth history characterized by the transition from simple to complex multicellular organisms and by extreme variations in climate eustasy and possibly tectonics understanding sinian stratigraphy may help interpret the co evolution of life and environment during the period though sinian successions are poorly dated and difficult to correlate preservation facies and sequence models based on mesozoic recent successions may be used to interpret them preservation models based on basin subsidence permit estimates of how thick and complete successions can be in different tectonic settings and how long it took for them to be deposited facies models for rift craton shelf slope and basin environments help in identification of these different tectonic settings sequence models facilitate interpretation of the interplay of tectonic subsidence eustasy rates of sedimentation and climate such models applied to the sinian successions of australia and asia indicate the following great shallowing upwards megacycles occur in sinian successions and each ends with regional glaciations deep rift basins formed around 850 800 ma preserve the oldest megacycles but these basins soon were filled with rapidly deposited glaciogenic sediments relatively complete sequences are found only in deep basins subject to repeated rifting cratons and shallow shelves preserve only the youngest megacycles older deposits have been removed by younger glacial advances deep shelves and slopes preserve one to three megacycles depending on the timing of the start of passive margin subsidence megasequences can be correlated based on limited radiometric dating and inferred regional distribution of unique rock types but these sequences are not developed to the same extent in all blocks problems in correlating the four great megacycles recognized elsewhere with those of asia will persist until the requisite facies analysis and u pb dating of interbedded volcanics are done

mechanisms of fast flow in jakobshavns isbrae west greenland part i measurements of temperature and water level in deep boreholes several holes were drilled to depths of 1500 1630 m along a profile across jakobshavns isbrae 50 km upstream from the calving front drilling was by hot water and required approximately 20 h the holes were rapidly closed by refreezing but it was possible to instrument them with thermistors and tilt sensors before this occurred near the margins of the ice stream the holes reached the bed and connected with the subglacial drainage system water level changes recorded in these holes are discussed in terms of the basal hydraulic system the temperature measurements show that the glacier is temperate based moreover extrapolation of a measured temperature profile and its curvature suggests that a temperate layer of substantial thickness may exist at the bed near the center of the ice stream there is a striking difference in the shapes of temperature profiles measured at different locations beneath the center line the temperature minimum is at a considerably smaller relative depth than near the margins but it is nearly the same in magnitude 22 1 c this may indicate a disproportionately large vertical stretching of the basal ice in the center of the ice stream since the basal ice is warmer and much less viscous than the ice above a thickening of that layer would cause a corresponding increase of surface velocity we presume that this mechanism contributes to the fast flow of jakobshavns isbrae

cordaiteans in paleotropical wetlands an ecological re evaluation abstract cordaiteans in cordaite dominated permineralized peat from pennsylvanian coals in iowa have been reconstructed as mangroves using root anatomy peat taphonomy and geochemical data macrofloral palynofloral and conodont biostratigraphy indicate that these peats come from the latest atokan blackoak coal and earliest desmoinesian cliffland coal mid moscovian both in the kalo formation thus their depositional setting can be used to evaluate the mangrove hypothesis in recent mires thick mangrove peats have accumulated in tropical to subtropical carbonate systems in contrast thick tropical freshwater peats have accumulated in siliclastic systems kalo formation coals which we interpret as freshwater deposits formed in siliciclastic depositional settings similar to those of modern tropical freshwater peat and to other pennsylvanian coals in north america interpreted as freshwater deposits in the late atokan and earliest desmoinesian mid moscovian cordaiteans and tree ferns predominated in the western interior and illinois basins lycopsids and cordaiteans predominated in the appalachian and donets basins the scarcity of lycopsid only mires in north america during the late atokan earliest desmoinesian mid moscovian suggests drier climates than during the mid to late desmoinesian late moscovian rather than indicating mangrove swamps cordaite dominated peat may indicate climates with a low rain season although most plants in cordaite dominated peat probably grew in freshwater coastal mires in climate zones with seasons of low rain may harbor mangrove taxa the changuinola swamp of panama a modern peat accumulating wetland that has a low rain season is a possible analog of ancient cordaite dominated mires in changuinola most plants require freshwater however mangroves sustained by salt water influx into the swamp grow along the seaward edge and along blackwater creeks the low rain season hypothesis has implications for understanding rainfall amount and continuity during pennsylvanian cyclothem deposition the floral succession in diverse cordaite coals from cordaiteans to tree ferns to lycopsids suggests increasingly wet climate during coal accumulation the position of these coals immediately above the sequence boundary suggests humid climate during early glacial melting for these cyclothems

neoproterozoic loess and limits to snowball earth abstract neoproterozoic tillites overlain by limestones and dolostones cap carbonates have been interpreted as evidence of abrupt climate change from glaciers to tropical seas on the assumption that cap carbonates were marine this assumption is here challenged by evidence for loess deposition of the nuccaleena formation of south australia from granulometry angular randomly oriented silt modal diameter 7 and sedimentary structures climbing translatent cross stratification linear dunes in addition a variety of palaeosols in the nuccaleena formation have red clayey horizons replacive micritization expansion cracks and thufur mounds as well as low carbon and oxygen isotope values high strontium isotope ratios and geochemical evidence of leaching and clay formation this cap carbonate has no definitively marine features and is here interpreted as periglacial loess overlying the fluvioglacial intertidal elatina formation so it is not a record of abrupt global warming from snowball earth other cap carbonates around the world differ in various ways and may have formed in different depositional environments but could profitably be reconsidered from the new perspective of the loess depositional model proposed here supplementary material tabular comparison of marine and non marine interpretations of cap carbonates petrographic textures and composition and new isotopic and chemical analyses of nuccaleena formation are available at http www geolsoc org uk sup18443

8000 years of vegetation dynamics and environmental changes of a unique inland peat ecosystem of the jambi province in central sumatra indonesia abstract despite their importance as global carbon sinks peatlands of southeast asia have been rarely studied and our current knowledge of the dynamics and ecology of these ecosystems remains incomplete paleoecological and palynological multi proxy analyses including analysis of pollen spores charcoal testate amoebae and sediments were carried out on a 733 cm long core taken from the air hitam peatland in the jambi province central sumatra indonesia the radiocarbon chronology reveals that peat formation started ca 7800 years ago the site was covered by dipterocarp swamp mixed rainforest during the first 2000 years after which freshwater swamp taxa became more important in particular durio trees this lasted until ca 4500 years ago when the swamp vegetation shifted to a pole forest with abundant pandanus thickets in response to a system change from minerotrophic to ombrotrophic conditions for this period macro charcoal analysis reveals that fire frequency increased possibly as a consequence of climate change linked to the onset of the modern el nino southern oscillation enso in the late holocene the ombrogenous pandanus pole forest phases were characterized by lower water table fluctuations and higher peat accumulation rates the area of air hitam has been for thousands of years a highly effective carbon sequestering peatland natural climate variability in the past did not affect the carbon storage function as suggested by the general increase in peat accumulation during relatively drier phases and increasing enso variability in the late holocene however the recent changes caused by selective logging drainage and conversion to oil palm plantations have caused a decline in the peat swamp forest communities changing the ecological functions of the peatland it is likely that the accumulated carbon will be released in the atmosphere due to exposure to aerobic conditions and its function will be lost unless a better management of the watershed is applied

trace and rare earth elemental investigation of a sturtian cap carbonate pocatello idaho evidence for ocean redox conditions before and during carbonate deposition abstract this study examines the trace element and ree y geochemistry of a thin pink dolomite in the scout mountain member of the pocatello formation idaho the pink dolomite meets the criteria of a cap carbonate and provides an opportunity to examine ocean redox state and hydrothermal inputs on the margin of laurentia at the terminal stages of the sturtian glaciations here high resolution chemostratigraphy of the dolomite shows that the local marine conditions were rapidly changing during cap emplacement normalized trace metal concentrations of zn cd cu cr mn and ni suggest that transiently reducing conditions prevailed immediately following the initial deposition of the pink dolomite enrichments in eu suggest a hydrothermal vent source for marine waters present during deposition the pink dolomite lacks evidence for persistent sulfide mineralization and its associated enrichments in mo suggesting that anoxia was restricted to areas below the sediment water interface no notable enrichments are recorded in the glacial diamictite though the signal might be masked by high rates of sedimentation our data suggest that the deposition of the pink dolomite progressed through 1 the overturn of local ocean containing a strongly stratified hydrothermally influence water column 2 the delivery of micronutrients to the shallow ocean 3 a biotic bloom in response to micronutrient availability and 4 related organic matter scavenging of metals finally we argue that this period of anoxia was brief and conditions quickly returned to an environment of oxic deposition

ice flow in the northeast greenland ice stream as the use of satellite data for icesheet research has accelerated new discoveries have changed the way that we think about ice discharge and new tools have changed the way that we measure it we have begun to apply a combination of remote sensing and ice sheet modeling techniques to study ice flow in the recently identified northeast greenland ice stream this ice stream shows evidence of organized flow far into the interior and has low slope areas of rapid flow and regions of enhanced shear that resemble the ice streams of west antarctica the onset of rapid flow close to the ice divide and the evolution of its flow pattern however make this ice stream unique our investigation is aimed at increasing our understanding of this ice stream and its origins and role in the discharge of ice from the ice sheet and the effects that discharge may have on the history and evolution of the ice in northern greenland the ice flow data comes from satellite radar interferometry tied to reference points we have applied this technique to measure the velocity over the entire ice stream which is more than 700 km in length the velocity contours reveal distinct well developed shear margins which are coincident with linear features in the synthetic aperture radar sar amplitude imagery it is surprising to see such defined enhanced flow so far inland and so close to the ice divide the velocity data and topography data are being used to feed a modeling effort that allows us to study the dynamics and character rapid flow additional information is contained in the original

new classification systems for tropical organic rich deposits based on studies of the tasek bera basin malaysia most schemes in common use for field and laboratory classification of peats were developed in boreal and humid temperate regions and do not recognize the distinctive features and specific uses of tropical peats such as those of the tasek bera basin in tropical peninsular malaysia the important aspects of peat texture morphology of constituents and their arrangement and laboratory ash content residue after ignition need modification to be valuable for classifying these and other tropical peat deposits in the tasek bera basin most of the deposits would not be considered as peat according to some classification schemes even though most have c contents 25 we propose a new three group fibric hemic sapric field texture classification applicable to tropical organic deposits which is similar to the system of the us soil taxonomy the classification is based on the following factors 1 visual examination of the morphology of the peat constituents texture and 2 estimates of fiber content and matrix finest fraction of peat consisting of highly humified organic matter and inorganic material the classification is applicable to all organic deposits with 35 loss on ignition we also present a new laboratory classification of organic soils based on ash and c content the us soil taxonomy classifies organic soils as having more than 12 18 organic c depending on clay content ash content and these limits for organic soils allow the discrimination of four main groups peat muck organic rich soil sediment and mineral soil sediment peat is defined as having an ash content of 0 55 muck 55 65 organic rich soil sediment 65 80 and mineral soil sediment 80 100 the peat class is further subdivided into very low ash 0 5 low ash 5 15 medium ash 15 25 high ash 25 40 and very high ash 40 55 subclasses

hypsometry and volume of the arctic ocean and its constituent seas 1 this paper presents an analysis of the arctic ocean and its constituent seas for seafloor area distribution versus depth and ocean volume the bathymetry from the international bathymetric chart of the arctic ocean ibcao is used together with limits defining this ocean and its constituent seas from the international hydrographic organization iho as well as redefined limits constructed to confine the seas to the shallow shelves ibcao is a bathymetric grid model with a resolution of 2 5 2 5 km which significantly improved the portrayal of the arctic ocean seafloor through incorporation of newly released bathymetric data including echo soundings from u s and british navies scientific nuclear submarine cruises and icebreaker cruises this analysis of seafloor area and ocean volume is the first for the arctic ocean based on this new and improved portrayal of the seafloor as represented by ibcao the seafloor area and volume are calculated for different depths starting from the present sea level and progressing in increments of 10 m to a depth of 500 m and in increments of 50 m from 550 m down to the deepest depth within each of the analyzed seas hypsometric curves expressed as simple histograms of the frequencies in different depth bins and depth plotted against cumulative area for each of the analyzed seas are presented the area and volume calculations show that the entire iho defined arctic ocean makes up 4 3 of the total ocean area but only 1 4 of the volume furthermore the iho arctic ocean is the shallowest mean depth 1201 m of all the major oceans and their adjacent seas the continental shelf area from the coasts out to the shelf break make up as much as 52 9 of the total area in the arctic ocean defined in this work as consisting of the oceanic deep arctic ocean basin the broad continental shelves of the barents kara laptev east siberian chukchi and beaufort seas the white sea and the narrow continental shelf off both the canadian arctic archipelago and northern greenland this result indicates that the arctic ocean has significantly larger continental shelves compared with all the other oceans where previous studies show that the proportion of shelves from the coasts out to the foot of the continental slopes only ranges between about 9 1 and 17 7 furthermore the derived hypsometric curves show that most of the arctic ocean shelf seas besides the barents sea beaufort sea and the shelf off northern greenland have a similar shape with the largest seafloor area between 0 and 50 m the east siberian and laptev seas in particular show area distributions concentrated in this shallow depth range and together with the chukchi sea they form a large flat shallow shelf province composing as much as 22 of the entire arctic ocean area but only 1 of the volume this implies that the circulation in the arctic ocean might be very sensitive to eustatic sea level changes one of the aims with this work is to make up to date high resolution area and volume calculations for the arctic ocean at various depths available for download

late pleistocene and holocene development of the interior peat accumulating basin of tropical tasek bera peninsular malaysia the stratigraphy of holocene peat deposits from an interior lowland basin of tropical peninsular malaysia provides insight into the hydrological ecological and climatic controls on tropical peatland development interpretations about vegetation and climate dynamics including storm intensity over the past 5000 years are integrated with regional and global climatic and eustatic changes to serve as a proxy for past ecology and climate tasek bera basin tbb is a lowland dendritic basin in tropical peninsular malaysia accumulation of organic matter occurred in local lakes during the last glacial maximum lgm but widespread peat deposition did not start until 5300 bp when climatic changes led to the evolution of a wetland system peat accumulation progressively expanded with terrestrialisation of channels and subbasins to paludification of the riparian part of the lowland forest zone lithofacies can be distinguished despite the highly diverse peat and organic rich sediment composition as a result of the climatic and hydrologic changes over the past 5300 years peat accumulation rates ranging from 0 7 to 2 5 mm year are highest in pandanaceae environments and lowest in high ash swamp forests and environments dominated by cyperaceae transects of peat cores across the mire system show the stratigraphic complexities of the peat is the result of hydrological variations and thus plant successional changes ash yield shows that periods of high mineral matter input into the drainage system occurred since the mid holocene indicating rapid and cyclic changes in frequency and magnitude of runoff events and by inference storms stratigraphic analysis of peat and ash yield are tools that provide a proxy for development of holocene hydrologic events in topogenous peat deposits

anisotropic texture of ice sheet surfaces 1 in this paper we analyze the magnitude and spatial organization of small scale surface features the surface texture of the greenland and antarctic ice sheets the texture is revealed in shaded relief maps of digital elevation models because surface slopes emphasize short wavelength topography we show that the surface slope components parallel to and perpendicular to the ice flow direction of ice sheets are both qualitatively and quantitatively different from one another the parallel component variations are larger in magnitude than the perpendicular component variations and features in maps of the parallel component are elongated perpendicular to the ice flow direction while features in maps of the perpendicular component are elongated at a diagonal to the ice flow direction these properties may be explained by a simple model of glacier dynamics in which a linearly viscous slab of ice flows over a random isotropic red noise bed in this model an anisotropic surface results from an isotropic bed because the surface anisotropy derives from the anisotropic transfer of bed topography to the surface by viscous flow dynamics the modeling results suggest that analysis of surface texture magnitude and anisotropy can be used to identify areas of sliding ice from surface topography data alone and can be used to roughly estimate sliding rates where bed topography is known

geochemical data as indicators of palaeosalinity in coastal organic rich sediments abstract a geochemical study of extractable major minor and trace elements peatlands from e spain elucidated variations in salinity related to the interpretation of relative sea level change samples were taken from different peatlands from the subsiding valencia castellon quaternary basin e spain these correspond to back barrier marshes with brackish and freshwater influence containing carex juncus typha and phragmites samples from a highland sphagnum moss freshwater peat bog were also included for comparison this paper categorizes palaeosalinity indicators in this coastal peat deposits as follows b br i na s ge u this compares with low rank coal which shows the following relationship b br i s na ge u the formulation of an index for characterising the organic detrital content using k or al concentration is also proposed this resulted in the following salinity index for peat b k br k i k na k s k ge k u k and for low rank coal b k br k i k s k na k ge k u k