turbulent viscosity in natural surf zones 1 waves breaking in the shallow surf zone near the shoreline inject turbulence into the water column that may reach the bed to suspend sediment breaking wave turbulence in the surf zone is however poorly understood which is one of the reasons why many process based coastal evolution models predict coastal change during severe storms inadequately here we use data collected in two natural surf zones to derive a new parameterization for the stability functionc that determines the magnitude of the eddy viscosity tin two equation turbulent viscosity models t c k2 e where k is turbulent kinetic energy and e is the turbulence dissipation rate in both data sets the ratio of turbulence production to dissipation is small 0 15 while vertical turbulence diffusion is significant this differs from assumptions underlying existing c parameterizations which we show to severely overpredict observed c for most conditions additionally we rewrite our new c parameterization into a formulation that accurately reproduces our reynolds stress based estimates of turbulence production this formulation is linear with strain consistent with earlier theoritical work for large strain rates also it does not depend oneand can therefore also be applied in one equation turbulent viscosity models we anticipate our work to improve turbulence modeling in natural surf zones and to eventually lead to more reliable predictions of coastal evolution in response to severe storms

accelerator mass spectrometer ages for the younger dryas event in atlantic canada abstract in atlantic canada bulk sediment dates for the onset of a late glacial cooling widely regarded as the younger dryas event are highly variable ranging from 14 300 270 to 10 800 100 yr b p we present the first accelerator mass spectrometer ams 14c dates from atlantic canada at or close to the boundaries of this event from six sites in new brunswick and nova scotia the mean of five dates places the onset of this cooling at ca 10 770 yr b p the inclusion of a sixth perhaps anomalously old date changes the mean to 10 880 yr b p the termination averages three dates ca 10 000 yr b p these dates place the timing of the younger dryas event in atlantic canada closer in line with the traditional chronozone boundaries of 11 000 and 10 000 yr b p in northwest europe

response of interior north america to abrupt climate oscillations in the north atlantic region during the last deglaciation several broad scale climatic oscillations during the last deglaciation are well documented in regions around the north atlantic ocean this paper reviews empirical evidence for these deglacial climatic oscillations from non coastal north america and discusses implications for testing climatic simulations and for understanding the cause and transmittal mechanisms paleoclimatic interpretation of oxygen isotope records from several small sites in the eastern great lakes region indicates a classic deglacial climatic sequence that is comparable with records from europe and greenland the climatic events as interpreted from crawford lake oxygen isotopes include the bolling allerod boa warming at 12 700 14c bp a warm boa at 12 500 10 920 14c bp an intra allerod cold period shortly before 11 000 14c bp a cold younger dryas yd climate reversal at 10 920 10 000 14c bp the holocene warming at 10 000 14c bp a brief preboreal oscillation pb at 9650 14c bp and an early holocene cold event at 7500 14c bp 8200 cal bp some of these events were also evident from changes in upland and aquatic vegetation and sediment lithology the pronounced yd climatic reversal has been documented from pollen records along the ecotones at this time and from glacier readvances in the great lakes region along the rocky mountains from alberta to colorado the yd event is indicated by alpine glacier advance and or shift in timberline vegetation in minnesota and upper new york early holocene climatic instability is also suggested by oxygen isotope records and or varve thickness the regional variations in evidence for the yd and other events in north america suggest that climatic oscillations may have different expressions in paleo records depending on geographic location and characteristics of a particular site the extent and magnitude of these climatic oscillations across north america suggest that these oscillations are an expression of climatic change that was probably widespread rather than locally induced by a nearby glacier the location of these sites implies that climatic signals were likely carried over the northern hemisphere through the atmosphere as indicated by general circulation models we hypothesize that the lack of evidence for a cold yd in interior north america west of the great lakes region and east of the rocky mountains was caused by the trapping of cold arctic air mass north of the laurentide ice sheet and by uninterrupted northward expansion of warm caribbean air this strongly contrasted climate also produced non analogous biological assemblages

vegetation et fluctuations climatiques postglaciaires sur la cote septentrionale gaspesienne quebec the postglacial ca 13 000 bp vegetational and climatic history is reconstructed from the pollen analytical study of the sediments of two lakes located in coastal northern gaspe peninsula j arrive lake altitude 56 m was submerged by the goldthwait sea until about 11 400 bp euloge lake 83 m in altitude and less than 1 km from the shore escaped the marine invasion before 10 400 bp the vegetation very scarce at first evolved to a herb tundra that lasted for over a millenium a cold climatic oscillation correlative with the younger dryas is identified at both sites between 10 700 and 10 400 bp during this herb tundra phase after 10 400 bp dwarf birch and willows colonized the sites leading to a shrub tundra the afforestation of the area began only around 9300 bp with the late arrival of spruce and aspen this phase was interrupted at 8650 bp by the upsurge of green alder in response to another cold oscillation since 7250 bp the present forested landscape finally developed in three steps characterized by i a high diversity of forest species until 2500 bp ii a loss of diversity until 1000 bp that favoured spruce and balsam fir and iii an increase of heliophilous trees shrubs and herbs these reconstructions contribute to the late glacial palaeogeography of eastern north america through the unravelling of conditions close to the retreating ice

late quaternary paleohydrology of the gulf of st lawrence quebec canada based on diatom analysis abstract postglacial sediments from three cores raised from the gulf of st lawrence along the path of the laurentian channel were analyzed for diatoms a sequence of four distinct zones was defined from oldest to youngest 1 characterized by low diatom concentrations this zone is mainly represented by heavily silicified species delphineis surirella stephanopyxis turris coscinodiscus radiatus and paralia ornata that were probably deposited by glacial drift in a glaciomarine environment from about 18 000 to 14 000 years bp 2 this postglacial sedimentation zone deposited around 13 000 years bp is marked by high diatom concentrations with cold water marine species thalassiosira antarctica resting spores and porosira glacialis the upper part of the zone suggests a gradual warming with the appearance of temperate water species bacterosira bathyomphala and chaetoceros spp both resting spores and vegetative cells 3 an important cooling of surface temperatures is noticed by the resurgence of cold species porosira glacialis thalassiosira antarctica resting spores and thalassiosira hyalina this zone is associated with the younger dryas chronozone dated from 10 800 to 10 300 years bp this interval is also characterized by two marked freshwater pulses coming from the outflow of laurentide ice sheet meltwater on the surface layer of the goldthwait sea although well defined in the northwestern gulf area core 90 031 015 the influence of this meltwater decreases considerably or even disappears in cabot strait core 89 007 111 and offshore core 90 031 044 evidence of reduced postglacial glacial runoff on surface water supports the conclusion that it could not have generated the younger dryas cooling episode 4 the diatom assemblages from 10 000 years bp through recent correspond to the progressive establishment of modern like surface water conditions

the climate of north america and adjacent ocean waters ca 6 ka the climate of north america and the adjacent ocean at 6000 bp was estimated using five independent approaches using pollen data the terrestrial climate was estimated by the movement of ecozone boundaries and by the method of modern analogues both analyses indicate warmer temperatures in the western great lakes area and the northern great plains a model of sphagnum dominated peatland initiation when forced by canadian climate model 6 ka output projected a cooler and or wetter climate for continental western north america contrary to this a reconstruction of the distribution of sphagnum dominated peatlands in western canada indicates that they were located north of their modern distribution suggesting warmer and or drier conditions at 6000 bp this interpretation is strengthened by observations of lower lake levels at 6000 bp in western canada this drier climate may have been associated with warmer conditions as indicated by the quantitative climate reconstructions in general eastern north a

geochemistry petrology and palynology of the pond creek coal bed northern pike and southern martin counties kentucky abstract the geochemistry petrology and palynology of the duckmantian age pond creek coal bed were investigated in northern pike and southern martin counties eastern kentucky the coal bed exhibits significant vertical variation in the investigated geochemical parameters with many diagenetic overprints of the original geochemistry included in the range of geochemical signatures are the presence of elements particularly tio 2 and zr suggesting the detrital influences at the time of deposition of a low vitrinite durain a high cao zone with elevated b be both suggesting marine influence in a lithotype in the middle of the coal bed and the postdepositional emplacement of pyrite in the uppermost lithotype individual lithotypes each representing distinct depositional environments all complicated to some degree by diagentic overprints comprise the complex history of the coal bed

the relative influence of laurentide and local ice sheets during the last glacial maximum in the eastern chic chocs range northern gaspe peninsula quebec geochemical signatures erratic dispersal and striae indicate glacial flows in the north central gaspe peninsula exclusively from appalachian sources except for the coastal fringe during the last glacial maximum lgm ice from the monts mcgerrigle flowed northward and northwestward over the summits of the eastern chic chocs range and the coastal plateau to the gulf of st lawrence lesser flows also occurred to the north from mont albert and the western chic chocs range where intersecting striae were noted the older flows are associated with a locally developed ice cap the rare occurrences of striae and erratics and morphometric and lithological characteristics of summit diamictons imply limited basal erosion by both local and regional ice caps this is postulated to result from early protection of rock surfaces by the initial buildup of thin frozen based ice in the eastern chic chocs range a compact till mantle in the cols and on the coastal plateau and striae parallel to col directions indica

comparison of marine and terrestrial holocene climatic reconstructions from northeastern north america quantitative climate reconstructions based on marine dinocysts and terrestrial pollen sequences are consistent through the holocene in northeastern north america principal components analysis pca indicates a large scale climate signal in the dinocysts and pollen the combined and separate analyses of marine and nearby terrestrial pollen sequences from hudson bay labrador and the st lawrence estuary differentiate tun dra boreal forest and deciduous forest assemblages in time and space these analyses indicate that the marine pollen record reflects vegetation changes of the regional terrestrial environment and allows direct correlations between the marine and terrestrial stratigraphies sea surface temperatures estimated from dinocysts and terres trial air temperatures from pollen using the method of modern analogs show that the three regions had differing climate histories associated with their location with respect to deglaciation and air mass boundaries high frequency climatic changes reconstructed

comparative radiocarbon dating of terrestrial plant macrofossils and aquatic moss from the ice free corridor of western canada in order to assess the reliability of aquatic moss for radiocarbon dating sup 14 c analyses were performed on a stratigraphic series of terrestrial plant macrofossils and samples of drepanocladus crassicostatus from a small hard water lake ph 8 2 in the ice free corridor of alberta all sup 14 c dating was done by using accelerator mass spectrometry mazama ash provided an independent chronological control the aquatic bryophyte samples consistently produced sup 14 c ages significantly older than the terrestrial macrofossils the relation between the radiocarbon dates from the macrofossils and the moss was not linear and age differences ranged from approximately 1400 to 6400 yr the sup 14 c content of d crassicostatus growing in the lake at present was less than 85 modern despite the apparent inability to take up sup 14 c deficient carbon by the direct incorporation of bicarbonate the bryophytes clearly do not provide reliable material sup 14 c dating the sup 14 c deficiency of aquatic mosses may be explained by the generation of sup 14 c deficient co sub 2 through isotopic exchange the formation of co sub 2 from bicarbonate by chemical processes and metabolic co sub 2 production these results demonstrate the potential unreliability of sup 14 c dates from aquatic mosses and raise serious concernsmore about the deglaciation dates from the ice free corridor that were obtained from aquatic drepanocladus less

mercury content of the springfield coal indiana and kentucky abstract with pending regulation of mercury emissions in united states power plants its control at every step of the combustion process is important an understanding of the amount of mercury in coal at the mine is the first step in this process the springfield coal middle pennsylvanian is one of the most important coal resources in the illinois basin in indiana and western kentucky hg contents range from 0 02 to 0 55 ppm the variation within small areas is comparable to the variation on a basin basis considerable variation also exists within the coal column ranging from 0 04 to 0 224 ppm at one kentucky site larger variations likely exist since that site does not represent the highest whole seam hg nor was the collection of samples done with optimization of trace element variations in mind estimates of hg capture by currently installed pollution control equipment range from 9 53 capture by cold side electrostatic precipitators esp and 47 81 hg capture for esp flue gas desulfurization fgd the high cl content of many illinois basin coals and the installation of selective catalytic reduction of no x enhances the oxidation of hg species improving the ability of esps and fgds to capture hg

wisconsinan late glacial environmental change in nova scotia a regional synthesis a synthesis of the interpreted vegetational and climatic history of nova scotia during the wisconsinan late glacial period 14 9 ka bp is presented and described in 500 year intervals the concomitant regional deglaciation history of the region is also described a synthesis chart is provided which includes a qualitative curve of temperature reconstructions for the late glacial period

paleothermicity in the central asturian coal basin north spain this research shows for the first time maps of vitrinite reflectances and paleotemperatures from the central asturian coal basin north spain which is a carboniferous pennsylvanian basin mainly of moscovian age vitrinite reflectance values decrease from north to south whereas volatile matter distribution increases from south to north vitrinite reflectance and volatile matter parameters indicate a coal rank ranging from high volatile bituminous coal in the north to semianthracite and anthracite in the south rock eval data show that the organic matter of this basin is type iii kerogen with a maturation ranging from oil to gas window paleotemperatures were calculated by diverse methods using vitrinite reflectance data for different durations of heating and rock eval results the calculated paleotemperatures and vertical paleotemperature gradients decrease from south to north the thermal gradient variation in the central asturian coal basin points to the influence of at least two heating events that affected the organic matter the first associated with a regular geothermal gradient operating over a long period of time and the second linked to a southern granitic event of short duration estimated by tectonic data the short thermal event was located at the end of sedimentation late moscovian and late westphalian d and after folding but before the overthrusting during the asturian tectonic phase located before the early kasimovian cantabrian and stephanian deposits finally a simulation of paleotemperatures around the granitic pluton was calculated and compared to maps of paleotemperatures obtained by various methods these maps refer to an initial depth of one or two km in accordance with the selected methods that are compatible with local erosion this approach was preferred in order to explain the metamorphism of coal rather than the hypothesis of hydrothermal fluid flow proposed for other foreland basins this regional thermal anomaly could be important for future coalbed methane assessment

vertical variations of mercury in pennsylvanian coal beds from indiana abstract twenty three in situ coal sections were sampled in indiana mines to investigate mercury hg concentrations with a special reference to in seam vertical variations in hg distribution in addition to raw coal corresponding float fractions were also analyzed to evaluate the effectiveness of hg reduction during conventional pre combustion washing hg content in indiana coals in the locations studied averages 0 11 mg kg which after recalculation into equal energy units corresponds to 9 2 lb hg 1012 btu 39 5 kg hg 1010 mj hg content is reduced after washing to 0 07 mg kg on average corresponding to an equal energy hg loading of 5 2 lb hg 1012 btu 22 3 kg hg 1010 mj a large portion of hg appears to be associated with pyrite as in the springfield coal member of the petersburg formation pennsylvanian in the samples from the danville coal member of the dugger formation pennsylvanian hg is associated to a larger extent with organic matter large differences in hg content may exist between different portions of a coal bed in a single location indicating that very careful complete sampling is necessary to get representative hg concentration data

mapped plant macrofossil and pollen records of late quaternary vegetation change in eastern north america abstract macrofossil presence absence maps and isopoll maps in 3000 year intervals show how ranges and abundance maxima for 12 eastern north american tree and shrub taxa picea p glauca p mariana larix laricina abies balsamea tsuga canadensis pinus strobus p resinosa p banksiana betula papyrifera b alleghaniensis b series humiles have changed from the last glacial maximum to the present the macrofossil maps corroborate patterns shown by the isopoll maps and provide spatial detail and taxonomic resolution the macrofossils confirm the inference from pollen data that unglaciated southeastern north america was cooler during the last glacial maximum 18 and 15 ka than simulated by the cohmap experiments with the ncar ccm0 general circulation model the geographic distribution of macrofossil occurrences during the late glacial 12 and 9 ka indicate that migration lag of boreal species did not occur at regional to subcontinental scales and that pollen assemblages lacking modern analogs resulted from climate gradients lacking modern analogs early holocene 9 and 6 ka macrofossil maps show rapid northward expansion of tree species ranges into deglaciated regions the data also show modest contractions of northern range limits of temperate species and expansions of southern range limits of boreal species in response to cooling trends during the late holocene 3 and 0 ka comparison of modern macrofossil maps of nine of these taxa with corresponding range maps confirm that the macrofossils record the geographic ranges accurately comparison of the modern macrofossil maps with maps of tree growing stock volume shows that for some taxa abies tsuga macrofossil occurrences were most frequent in regions of maximum tree abundance comparison of modern isopoll maps with the modern range and growing stock volume maps indicate that in contrast to the macrofossil data the pollen data provide poorer resolution of range limits for most taxa but better indications of abundance maxima and minima within the ranges

mechanisms of coal metamorphism case studies from paleozoic coalfields controls on coal metamorphism can be complex in this paper we examine four paleozoic coalfields the western kentucky portion of the illinois basin the pennsylvania anthracite fields the south wales coalfield and the bowen basin an increase in temperature with depth of burial is certainly a factor in coal metamorphism in many coalfields however including the coalfields reviewed here it has become apparent that such a simple mechanism does not explain the coal rank patterns observed the flow of hydrothermal fluids through the coals has been proposed as a cause of coal metamorphism evidence includes inverted rank gradients elevated cfl as an indicator of brine fluids isotopic evidence for hydrothermal fluids and vein and cleat mineral assemblages in any case multiple hypotheses must often be evaluated in the examination of any coalfield since the simple paradigm of coal rank increases with a simple increase in temperature with increasing depth does not fit the evidence observed in many cases

cooling in the gulf of st lawrence and estuary region at 9 7 to 7 2 14c ka 11 2 8 0 cal ka palynological response to the pbo and 8 2 cal ka cold events laurentide ice sheet air mass circulation and enhanced freshwater runoff abstract an examination of post younger dryas yd pollen stratigraphies in the gulf of st lawrence and st lawrence estuary region reveals features in the pollen records that represent breaks in the normal vegetation succession widespread vegetation suppression and a delay in migration of plant taxa between 9 7 and 7 2 14 c ka 11 2 and 8 0 cal ka the domination of alnus crispa at sites bordering the st lawrence estuary gulf region in gaspesie and northern new brunswick within this timeframe represents a diversion from the typical vegetation progression from picea and or populus or picea betula to pinus and or betula and signifies a shift to a cooler drier climate coinciding with the a crispa expansion and domination in that region was the contraction of picea populations in other areas in southwestern new brunswick and eastern and southeastern nova scotia picea was replaced by the first appearance of tree birch b papyrifera whereas in western and southwestern newfoundland picea gave way to a resurgence of shrub birch betula glandulosa the picea contraction and immediate resurgence of betula represents cooling and is reliably dated at 9720 110 14 c bp 10 800 11 240 cal bp in southwest newfoundland this first post yd episode of widespread cooling is correlated with the north atlantic preboreal oscillation pbo centered around 9650 14 c bp 10 900 11 180 cal bp in the adjacent great lakes region sites exposed to winds from the gulf of st lawrence in eastern new brunswick prince edward island and northern nova scotia show a lingering persistence of picea and delay in arrival of pinus to 8 0 and 7 7 14 c ka 9 0 and 8 4 cal ka yet pinus was dominant as early as 9 4 14 c ka 10 6 cal ka in southwestern new brunswick at the same time tundra vegetation persisted at high elevations in western and southwestern newfoundland only to be replaced by upslope migration of shrub birch heath by 8 14 c ka prolonged broad scale cooling to 8 14 c ka and to as late as 7 7 14 c ka extended up to 200 km inland in areas exposed to the st lawrence estuary and gulf region and was in response to strong cold dry anticyclonic winds coming off the retreating laurentide ice sheet in combination with enhanced freshwater runoff through the gulf of st lawrence the end of the period of prolonged cooling and onset of regional warming coincided with the diversion of western canada runoff and agassiz ojibway drainage to hudson bay and reduced effect or final break up of the laurentide ice sheet several sites document a subsequent cold shift that interrupted regional warming at 7650 to 7200 14 c bp 8400 to 8000 cal bp and which is variously represented by the suppression of pinus and resurgence of picea sometimes with a crispa quebec maritime region or by an abrupt decrease of picea and resurgence of betula western newfoundland this second post yd cool interval is equated with the 8200 cal bp cold event registered in the greenland ice isotopic record

postglacial palaeophytogeography of the eastern st lawrence river watershed and the climatic signal of the pollen record abstract pollen analytical studies of the sediments of over 150 lakes and bogs in southern quebec have led to the indentification of a limited number of sequential types or temporal suites of the various pollen assemblages within each of three main stages of the postglacial development of vegetation the non arboreal stage the afforestation stage and the forest stage these sequential types within any of the three stages show distinct geographical and chronological distributions in southern quebec during the last 12 000 yr when compared in a broader geographic context they demonstrate a strong differentiation of the pollen record within and around the great lakes st lawrence river watershed during the last 15 000 yr b p amongst the most striking gradients identified stand the late glacial perichamplainian gradients ca 11 500 10 000 yr b p and the early holocene gradients the former involve seaward and northeastward clines from closed coniferous forests to tundras and the latter northeastward changes in the nature and duration of the afforestation stage the modern pattern of even the broader vegetational gradients in southern quebec was not attained before 3000 yr b p palynological reconstruction of the various regional paleoclimates highlights the interaction of local regional and global climatic forcings through time mesoscale climate modelling and palaeoclimatology should find boundary conditions in those regional reconstructions

wisconsinan late glacial environmental change in newfoundland a regional review the distribution of 75 lake and bog sites from which pollen stratigraphical evidence relevant to the late quaternary of newfoundland has been obtained is presented the detailed records of lithology pollen and diatoms supplemented by geochemical data are discussed for three of the sites southwest brook lake woody hill brook pond and leading tickles and interpretations made are based on vegetational history relative climatic changes and extent of ice cover radiocarbon data from 14 sites are summarised a summary chart of late glacial environmental changes including a qualitative palaeotemperature curve is provided

effects of environmental change on scree slope development throughout the postglacial period in the chic choc mountains in the northern gaspe peninsula quebec abstract the combined study of present day processes and stratigraphic data has permitted the reconstruction of the dynamics of scree slopes of the northern gaspe peninsula throughout the postglacial period in this region liberated progressively from beneath an ice cover between 13 500 and 10 000 years bp the scree slopes have to be seen as an integral part of a regional geosystem evolution of these slopes has been rapid influenced by local paraglacial conditions glacio isostatic rebound glacio eustatic fluctuations and re equilibration of glacially over steepened rockwalls which operated against a backdrop of late glacial and holocene climatic fluctuations during the younger dryas and part of the early holocene period as the foot slopes emerged from beneath the goldthwait sea the basal part of several scree slopes advanced onto marine terraces as lobate rock glaciers under the influence of a periglacial climate characterised by permafrost many scree slopes continued to transfer debris downslope after regional establishment of a closed forest cover at ca 7250 years bp forest colonisation in the early pre emergent phase of the postglacial period was retarded due to constant replenishment of the debris removed from the foot slopes by marine processes in the later post emergent phase development of a complete forest cover has only been possible on slopes where the summit rockwall segment has been completely eliminated a condition not yet fulfilled for many geomorphologically active scree slopes of the region in fact both of these paraglacial influences have been diachronous on a regional scale advance upslope of the forest front on the scree slopes appears to have been slow difficult and subject to periodic regressions of possible climatic origin as indicated by numerous buried soils in colluvial stratigraphic sequences and for the past 150 years by dendro ecological studies stratigraphic exposures along with direct observation of slope events have revealed the operation of a large variety of debris transfer processes including niveo aeolian sedimentation and frost coated clast flows the latter representing an important process first recognised on the scree slopes of gaspesie

holocene vegetation dynamics of anticosti island quebec and consequences of remoteness on ecological succession abstract the postglacial vegetation history of anticosti island in the gulf of st lawrence quebec was reconstructed from pollen analysis of three sites providing the first paleoecological data for the island the earliest plant communities 8550 7770 14c yr b p 9500 8500 cal yr b p were characterized by a high representation of green alder alnus crispa indicating an open environment with sparse spruce picea between 7770 and 3700 14c yr b p 8500 4000 cal yr b p the island was colonized by mixed deciduous and coniferous forests dominated by paper birch betula papyrifera and spruce a major increase in the abundance of balsam fir abies balsamea occurred ca 3700 14c yr b p 4000 cal yr b p indicating development of the closed fir spruce forests as they exist today the island s remoteness from continental seed plant sources influenced plant colonization afforestation and ecological succession the gulf of st lawrence slowed plant migration and tree species had to spread from the gaspe peninsula repeated drops in fir pollen percentages during the last 4 000 years may reflect the activity of defoliating insects

tracking mercury from the mine to the power plant geochemistry of the manchester coal bed clay county kentucky abstract the high volatile a bituminous manchester coal bed was sampled at five mine sites in central clay county southeastern kentucky the coal bed has a high mercury concentration at certain sites particularly in the high sulfur uppermost lithology whole coal hg contents range up to 0 52 ppm in a sample with 3 36 pyritic sulfur hg is enriched in the upper lithotype at several of the sites arsenic content exceeds 700 ppm ash basis for all of the whole channel samples and exceeds 1000 ppm for several of the lithotype samples regional geochemical trends from an area of approximately 75 60 km were determined using data from this study in combination with data published by the u s geological survey hg as pb and cl contents exhibit highs in the northwestern portion of the region within the smaller area covered by the detailed mine study the two western sites both have a high sulfur upper lithotype containing high levels of as and hg basement structures previously described in the study area could have influenced the regional coal rank and geochemistry possibly acting as conduits for mineralizing fluids

sudden changes in north atlantic circulation during the last deglaciation sudden changes in the flow of warm atlantic surface waters into the norwegian sea occurred frequently during the last deglaciation typically involving shifts in sea surface temperature of 5 c in fewer than 40 years these led to equally large and rapid changes in atmospheric temperatures and to shifts in atlantic deep thermo haline circulation and ice sheet melting rates

notes on the marginal enrichment of germanium in coal beds germanium distribution in coal has long been a topic of interest the enrichment of ge near margins of coals including the margins of partings within the coal has been noted in many coals from numerous coalfields throughout the world in this paper a summary of literature on ge geochemistry on the upper and lower margins of coal seams with special emphasis on the literature of russia and the former soviet union and japan is presented

wisconsinan late glacial environmental chage in new brunswick a regional synthesis a synthesis is presented of the history of deglaciation vegetation cover and climate in new brunswick canada during that part of the wisconsinan late glacial period 12 9 ka bp for which detailed records exist curves of inferred temperature variations in the region during this period are presented based upon qualitative interpretations of plant records and quantitative estimates based upon fossil chironomid assemblages

geological and geochemical characteristics of high arsenic coals from endemic arsenosis areas in southwestern guizhou province china southwest guizhou province is one of the most important areas of disseminated sediment hosted type au deposits in china and is an important area of coal production the chemistry of most of the coals in sw guizhou is similar to those in other parts of china their as content is near the chinese coal average but some local small coal mines contain high as coals the highest as content is up to 3 5 wt in the coal the use of high as coals has caused in excess of 3000 cases of as poisoning in several villages the high as coals are in the longtan formation which is an alternating marine facies and terrestrial facies the coals are distributed on both sides of faults that parallel the regional anticlinal axis the as content of coal is higher closer to the fault plane the as content of coal changes greatly in different coal beds and different locations of the same bed geological structures such as anticlines faults and sedimentary strata control the distribution of high as coals small au deposits as well as sb hg and th mineralization are found near the high as coals although some as bearing minerals such as pyrite arsenopyrite realgar as bearing sulfate as bearing clays and phosphate are found in the high as coals their contents cannot account for the abundance of as in some coals analysis of the coal indicates that as mainly exists in the form of as5 and as3 perhaps combined with organic compounds the occurrence of such exceptionally high as contents in coal and the fact that the as is dominantly organically associated are unique observations

ecosystem response to lateglacial and early holocene climate oscillations in the great lakes region of north america abstract fossil pollen plant macrofossils gastropods and elemental and stable isotope geochemistry in a sediment core from twiss marl pond southern ontario canada were used to document climate oscillations during the last glacial interglacial transition 13 000 8500 14 c bp and understand their ecological effects chronology was provided by ams 14 c dating and regional pollen correlation oxygen isotope 18 o results from mollusc shells chara encrustations and bulk carbonates show a classic climate sequence of a warm bolling allerod boa at 12 500 10 920 14 c bp a cold younger dryas yd at 10 920 10 000 14 c bp the holocene warming at 10 000 14 c bp a brief preboreal oscillation pb at 9650 14 c bp and a possible gerzensee killarney g k cooling shortly before 11 000 14 c bp clay sediments at the base of the core contain high herb and shrub pollen and abundant arctic alpine plant macrofossils indicating a treeless tundra with severe soil erosion in watershed during the boa warm period authigenic marl began to be deposited and picea woodland became established the establishment of picea woodland after peaks of 18 o and of carbonate accumulation suggests a lagged response of upland vegetation to boa warming in contrast the occurrence of warmth loving aquatics najas flexilis and typha latifolia at that time indicates sensitive responses of aquatic plants the yd cooling is indicated by a 1 5 negative excursion in 18 o an increase in minerogenic matter and higher concentrations of erosion derived elements al na k ti and v pollen data show no forest transformation in response to yd cooling which is attributed to the insensitive nonecotonal vegetation at that time however more openings in the forests and increased erosion in the watershed are indicated by a slight increase of herb pollen high concentrations of erosion elements and a pediastrum peak the onset of the holocene was marked by an abrupt increase of 2 in 18 o and the replacement of picea woodland by pinus dominated forest the picea recurrence at 9650 14 c bp demonstrates sensitive response of ecotonal vegetation to the pb climate oscillation which is also indicated by 0 4 negative excursion of 18 o these new results suggest the importance of multiproxy records for reliable paleoclimate reconstruction reevaluation and revised chronologies of previously published sites gage street and nichols brook in the eastern great lakes region show their major 18 o shifts correlative to the yd and pb oscillations as documented from twiss marl pond and nearby crawford lake the sequence and magnitude of climatic oscillations from these sites match in detail with records from the atlantic seaboard suggesting that these oscillations are an expression of broad scale probably global climate change rather than local meltwater induced climate cooling