utility of coal petrology for sequence stratigraphic analysis abstract sequence stratigraphy seeks to predict the depositional architecture of sediments based on the principle that their superposition and lateral arrangement are largely determined by the rate at which accommodation is made below depositional base level relative to the supply rate of sediments depositional base level is generally correlated with sea level which in paralic peat coal deposits controls the position of the groundwater table above which oxidation ablation and erosion would occur the current late quaternary sequence is used to discuss some of the constraints on coal formation that stem from the interaction of short and long period modulations on sequence forming eustatic cycles the results show that the mid transgressive systems tract is unlikely to produce significant coal deposits which is supported by a survey of the relevant literature from eight different countries it reveals a bimodal distribution of coal deposits with the strongest mode being situated in the early transgressive systems tract while a broader secondary mode occurs in the early and mid highstand position this concentration contrasts with the complete absence of any significant coal deposits in the early and mid lowstand systems tract and only a low occupancy of the late highstand systems tracts the reasons for this distribution are briefly discussed and attention is drawn to the possible over stating of the coal forming potential of the late lowstand systems tract following a brief discussion of the sequence stratigraphic interpretation of coal measures emphasis is put on the application of sequence stratigraphy to the study of coal seams and their composition at various levels of petrographic detail while in low rank coals botanical affinities contribute much to the lithotype based analysis a genetic assessment of bituminous coal seams relies primarily on physical and chemical palaeo environmental signatures simple properties such as maximum coal thickness low detrital mineral content and maximum preservation of vitrinite particularly of telovitrinite define a good balance between the former rates of accommodation versus peat accumulation iso metamorphic variations in telovitrinite reflectance and its dispersion measured by the coefficient of variation have also contributed to the palaeo environmental interpretation this paper confirms the identification within coal seams of most of the sequence stratigraphically significant surfaces e g sequence and parasequence boundaries transgressive flooding and maximum flooding surfaces it also gives examples of some new ones referred to as accommodation reversal non marine flooding give up transgressive terrestrialisation and paludification surfaces some of these are specific to coal measures but the give up transgressive and accommodation reversal surfaces may have wider significance

truncated higher order sequences as responses to compressive intraplate tectonic events superimposed on eustatic sea level rise abstract high resolution sequence stratigraphic analysis of the lignite bearing miocene siliciclastic sequence of the salotarjan lignite formation slf has been performed by lithostratigraphic dissection of more than 1350 boreholes and by detailed analysis of well logs from more than 150 boreholes biostratigraphic data indicate that the slf represents a single 3rd order eustatic sequence namely the bur 4 of vakarcs et al vakarcs g hardenbol j abreu v s vail p r varnai p tari g 1998 oligocene middle miocene depositional sequences of the central paratethys and their correlation with regional stages sepm special publication vol 60 209 231 as for facies conditions facies models for sandy shorefaces and or wave dominated deltas can be applied twenty six parasequences have been identified and mapped in the adjacent sub basins from well log correlations the sharp based sand bodies of ps 10 and 17 were interpreted as the falling stage systems tract fsst of higher order sequences the subsequent transgressive systems tracts tst are represented by retrograding sets of 2 3 parasequences ps 11 13 18 19 based on the regional unconformity at the base and the regionally extended sharp based sand bodies three sequence boundaries sb were determined that dissect the 3rd order sequence into three higher order sequences one of the special features of the sequence is that the fssts interrupt the rapid relative sea level rises ps 9 and 16 and lie directly on the silty material of nearshore environments leading to the lack of the higher order highstand system tracts hst truncated transgressive semi cycles another characteristic is the striking basinward fore stepping of the sedimentary depocentres and that of the facies belts of the lignite seams the rapid relative sea level falls implied by the two fssts are unexpected in the context of an overall eustatic rise thus the possibility of tectonic origin of shallowing was investigated this verification was based primarily on the observations that 1 the basin was united when parasequences 1 to 13 were developed whereas 2 by the end of the sequence development the palaeozoic basement protruded to the surface dividing the basin reflecting intense tectonic events simultaneous with sequence development the fssts with the sbs above and the formation of higher order sequences can thus be regarded as sedimentary responses to syn sedimentary tectonic elevation and tilting of the basement this elevation was induced by tectonic compression and associated imbrication along a regional reverse fault that was known as the darno line the imbrication could have controlled not only the repeated relative sea level falls but also the striking fore stepping of the sedimentary depocentres and facies belts of the associated lignite seams tectonic tilting influenced not only the fssts but the subsequent early tsts as well thus lignite seams associated with the tectonically counteracted tsts are characterized by multiple seams with several accessory seams va iiia b and ia while those associated with tectonically quiescent periods are aerially extensive and solitary comparison with other coal bearing formations enhanced the importance of the fsst in the interpretation of stratigraphic truncations coal seam geometry conditions facies shiftings and stratal geometry enabling a more accurate description of syn sedimentary tectonic events

depositional controls on coal distribution and quality in the eocene brunner coal measures buller coalfield south island new zealand abstract the buller coalfield on the west coast of the south island new zealand contains the eocene brunner coal measures the coal measures unconformably overlie paleozoic cretaceous basement rocks and are conformably overlain by and laterally interfinger with the eocene marine kaiata formation this study examines the lithofacies frameworks of the coal measures in order to interpret their depositional environments the lower part of the coal measures is dominated by conglomeratic lithofacies that rest on a basal erosional surface and thicken in paleovalleys incised into an undulating peneplain surface these lithofacies are overlain by sandstone mudstone and organic rich lithofacies of the upper part of the coal measures the main coal seam of the organic rich lithofacies is thick 10 20 m extensive locally split and locally absent this seam and associated coal seams in the buller coalfield are of low to high volatile bituminous rank vitrinite reflectance between 0 65 and 1 75 the main seam contains a variable percentage of ash and sulphur these values are related to the thickening and areal distribution of the seam which in turn were controlled by the nature of clastic deposition and peat forming mire systems marine transgression and local tidal incursion the conglomeratic lithofacies represent deposits of trunk and tributary braided streams that rapidly aggraded incised paleovalleys during sea level stillstands the main seam represents a deposit of raised mires that initially developed as topogenous mires on abandoned margins of inactive braidbelts peat accumulated in mires as a response to a rise in the water table probably initially due to gradual sea level rise and climate and the resulting raised topography served as protection from floods the upper part of the coal measures consists of sandstone lithofacies of fluvial origin and bioturbated sandstone mudstone and organic rich lithofacies which represent deposits of paralic deltaic barrier shoreface tidal and mire and marine environments the fluvial sandstone lithofacies accumulated in channels during a sea level stillstand the channels were infilled by coeval braided and meandering streams prior to transgression continued transgression ranging from tidal channel estuarine incursions to widespread but uneven paleoshoreline encroachment accompanied by moderate basin subsidence is marked by a stacked back stepping geometry of bioturbated sandstone and marine mudstone lithofacies final retrogradation sea level highstand is marked by backfilling of estuaries and by rapid landward deposition of the marine kaiata formation in the late eocene

stomatal proxy record of co2 concentrations from the last termination suggests an important role for co2 at climate change transitions a new stomatal proxy based record of co2 concentrations co2 based on betula nana dwarf birch leaves from the hasseldala port sedimentary sequence in south eastern sweden is presented the record is of high chronological resolution and spans most of greenland interstadial 1 gi 1a to 1c allerod pollen zone greenland stadial 1 gs 1 younger dryas pollen zone and the very beginning of the holocene preboreal pollen zone the record clearly demonstrates that i co2 were significantly higher than usually reported for the last termination and ii the overall pattern of co2 evolution through the studied time period is fairly dynamic with significant abrupt fluctuations in co2 when the climate moved from interstadial to stadial state and vice versa a new loss on ignition chemical record used here as a proxy for temperature lends independent support to the hasseldala port co2 record the large amplitude fluctuations around the climate change transitions may indicate unstable climates and that tippingpoint situations were involved in last termination climate evolution the scenario presented here is in contrast to co2 records reconstructed from air bubbles trapped in ice which indicate lower concentrations and a gradual linear increase of co2 through time the prevalent explanation for the main climate forcer during the last termination being ocean circulation patterns needs to re examined and a larger role for atmospheric co2 considered

a rapid climatic change at the end of the younger dryas in south sweden palaeoclimatic and palaeoenvironmental reconstructions based on fossil insect assemblages a rapid climatic change at the end of the younger dryas in s sweden palaeoclimatic and palaeo environmental reconstructions based on fossil insect assemblages

holocene recolonization and extinction of the pond turtle emys orbicularis l 1758 in europe we reconstruct the holocene range fluctuations of the european pond turtle emys orbicularis for northern and central europe based on 529 subfossil records and radiocarbon dating of critical finds we provide evidence that e orbicularis experienced a rapid range expansion with holocene warming phylogeographic data argue for a colonization of northern and central europe from a glacial refuge located in the south eastern balkans already in the late preboreal 9100 8600 cal bc the species occurred in northern central europe and was widespread in denmark and southern sweden skane during the boreal 8600 7100 cal bc the maximum range extension occurred during the holocene climatic optimum atlantic 7100 3750 cal bc with records in southern england middle sweden and northern estonia after the early subboreal 3750 1750 cal bc northern populations collapsed coinciding with a climatic cooling and oceanization northern populations were most likely established via long distance dispersal rafting using rivers debouching in the north and baltic seas after northern europe was reached a minimum dispersal of 50 km per 100 years may be hypothesized for the boreal c 2007 elsevier ltd all rights reserved

summer temperature gradients in northwest europe during the lateglacial to early holocene transition 15 8 ka bp inferred from chironomid assemblages abstract we present a series of summer air temperature isotherm maps based on chironomid inferred temperatures from northwest europe covering the lateglacial and early holocene 15 8 ka bp these maps are the first of their kind and use data derived from 22 lateglacial sites and 34 early holocene sites the isotherms are generated by weighted spatial interpolation kriging the major patterns of chironomid inferred summer temperatures are spatially well resolved in both the lateglacial and early holocene the isotherm maps indicate that there was a strong west to east gradient during the lateglacial interstadial gi 1 due to the influence of thermohaline circulation in the regions bordering the north atlantic which diminishes eastwards a strong north to south temperature gradient is also apparent particularly in eastern regions influenced by the extent of the scandinavian ice cap peak temperatures are achieved early in the interstadial in the south of the region but occur towards the end of the interstadial in the north holocene warming varies spatially and temporally and is earliest in the south and east but later in the north and west during the period covered in our study maximum warmth is reached ca 10 ka bp the chironomid based lateglacial isotherm maps are compared with previously published isotherm maps from the same region based on beetle inferred temperatures while the trends shown in the two datasets are similar beetle inferred temperatures are often warmer than chironomid inferred temperatures this is especially marked in gi 1e and may be due to microclimatic effects causing the chironomids to underestimate air temperatures and or the beetles to over estimate air temperatures the spatial coherence between sites in both the lateglacial and early holocene suggest that the chironomid based temperature estimates are largely reliable although data testing suggests that estimates from southern scandinavia may be less reliable perhaps due to high topographical relief influencing local climate more data points are required particularly from northwest scotland southwest england and wales northeast france denmark finland and the baltic states to confirm trends and provide even coverage and a denser network of sites

interaction between faulting and sedimentation during dinantian extension of the solway basin sw scotland the ene wsw trending north solway fault acted as a northern marginal fault to the solway basin during dinantian sedimentation structural sedimentological and diagenetic relationships suggest syn sedimentary dinantian movement was dip slip and normal a later carboniferous phase of dextral transtension is also indicated allokinetic deformation features increase in abundance and intensity towards the north solway fault their presence and nature being strongly facies dependent syn sedimentary fault deformation of the hanging wall sediments also increases towards this fault both distributed and localized shearing characterizes these early faults and is thought to be related to the water content of beds at the time of deformation local minor thrusting and reverse fault movement also occurred within the sediments during basin extension due to dextral transtensional movement on the north solway fault n s and nw se trending faults appear to show no evidence for syn sedimentary dinantian movement and are interpreted as the products of 9hercynian9 basin shortening and mesozoic basin formation

data model comparison of the younger dryas event discussion rutter et al 2000 present an interesting overview of global evidence for the younger dryas event yd 11 500 13 000 calendar years ago as inferred from various kinds of proxy data such an overview is important for a better understanding of mechanisms behind rapid climate change moreover rutter et al make an effort to compare these data with a coupled atmosphere ocean model experiment on the yd performed by fanning and weaver 1997 in this experiment the production of north atlantic deep water nadw collapses after the release of a large amount of fresh water in the north atlantic based on the data model comparison rutter et al conclude that the model results reveal a global pattern and regional magnitude which generally agree with temperature changes interpreted from paleoclimatic reconstructions abstract p 811 this implies that the yd temperature change is

atmospheric variability over the 14 7 kyr bp stadial interstadial transition in the north atlantic region as simulated by an agcm the echam4 t42 atmospheric general circulation model was applied to study the change in atmospheric variability in the north atlantic region over the similar to14 7 kyr cal bp climatic transition from greenland stadial 2a gs 2a end of pleniglacial to greenland interstadial le gi le start late glacial the following three climates are simulated 1 present day 2 gs 2a and 3 gi le we focus on climatic parameters near the earth s surface temperature precipitation and sea level pressure results on two different temporal scales are analysed seasonal and daily the seasonal fields show that the main change over the 14 7 kyr bp transition occurred in winter we calculated daily standard deviations of temperature and pressure about the seasonal means and the high pass filtered less than six days variability of pressure the largest change in atmospheric variability occurred in northwest europe here the daily temperature variability decreased by 50 whereas storm activity also decreased substantially these changes are related to a northward shift of the atlantic sea ice margin at 14 7 kyr bp leading to a northward relocation of the atlantic storm track in the gs 2a experiment a strong storm track was located over northwest europe where frequent depressions produced alternations of northerly air flow below 30 degreesc and southerly air flow close to 0 degreesc this strong daily atmospheric variability decreased in gi le because the storm track had a sw ne orientation over the atlantic towards iceland the decrease in atmospheric variability at 14 7 kyr bp probably contributed to landscape stabilization for instance through decreasing eolian transport

early holocene temperature variability inferred from chironomid assemblages at hawes water northwest england this paper presents the first high resolution chironomid inferred mean july air temperature c it reconstruction for the early holocene from england the reconstruction is based on a core recovered from a terrestrialised carbonate bench at hawes water a small hard water lake in northwest england the record shows that temperatures rose rapidly after the younger dryas with temperatures reaching 14 0 c at the beginning of the holocene over millennial timescales the temperature record points to a slight rise in temperatures towards the top of the sequence at around 8000 years before the year 2000 b2k the trend is punctuated by a series of cool oscillations at 11 200 11 400 10 700 10 400 9300 and 8300 b2k and by a short period 11 300 to 10 250 b2k when temperatures were considerably warmer up to 14 9 c the five cool oscillations coincide with temperature reversals found elsewhere in the north atlantic region and in the greenland ice core records these cool events correlate well with both me

the mid cenozoic challenger rift system of western new zealand and its implications for the age of alpine fault inception analysis of the structure and sedimentary geology of western new zealand has identified a middle eocene to early miocene continental rift system 1 200 km long and 100 200 km wide named here the challenger rift system four phases of rift development occurred 1 infra rift subsidence 2 active axial trough subsidence 3 expanded rift subsidence involving collapse of the rift shoulders and 4 incipient sea floor spreading the spatial and temporal distribution of these phases identifies a north island and a south island rift segment and shows that rifting propagated toward the center of the rift from both ends the northern segment shows a simple pattern of rifting that is comparable with vink9s model of rift propagation the southern segment with locked zones and rift nucleation segments is comparable to courtillot9s model of rift propagation the sea floor spreading history of the southwest pacific shows that the northern rift segment probably linked with a sea floor spreading center in the norfolk basin and the southern segment linked with the southeast indian ridge this is corroborated by the good correlation between the ages of sea floor magnetic anomaly lineations that are aligned with the rift and the biostratigraphic ages of rifting the probable continuity of the rift system in its early development precludes pre miocene transcurrent displacement on the alpine fault an early miocene 23 m y b p age of alpine fault inception is indicated by the age and pattern of rift disruption attributed to compression that originated at the australia pacific plate boundary the modern australia and pacific plates were not discrete entities therefore until the early miocene

sedimentary structures associated with extensional fault movement from the westphalian of ne england at an opencast coal mine in southern co durham close to the major butterknowle fault an exposed upper westphalian a sequence displays a plethora of tectonically associated structures fractures across the area of the opencast site were found to contain high concentrations of minerals which were apparently introduced at the time of formation of the n pennine orefield carboniferous permian from authors

a late weichselian stable isotope stratigraphy compared with biostratigraphical data a case study from southern sweden late weichselian lake sediments from a site in southern sweden were analysed for stable carbon and oxygen isotopes as well as plant macrofossils and insect remains by comparison of independent d

the origin and tectonic significance of asymmetrical meander belts in the hebgen lake area of sw montana the madison and south fork rivers occupy the northeast sides of their respective meander belts the form of the abandoned meander loops within these asymmetric meander belts indicates that they were produced by gradual northeast migration of the active channels this progressive migration can be related to tectonic tilting produced by regional extensional faulting at a high angle to the original channel belt axis which ran down a gently sloping outwash cone asymmetric channel sandstone bodies in the rock record can be recognized by the preferred dip of successive lateral accretion units in meander loops together with soft sediment deformation facies and thickness variations they may indicate tectonic deformation of the sedimentary surface

sequence stratigraphic distribution of coaly rocks fundamental controls and paralic examples significant volumes of terrigenous organic matter can be preserved to form coals only when and where the overall increase in accommodation approximately equals the production rate of peat accommodation is a function of subsidence and base level for mires base level is very specifically the groundwater table in paralic settings the groundwater table is strongly controlled by sea level and the precipitation evaporation ratio peat accumulates over a range of rates but always with a definite maximum rate set by original organic productivity and space available below depositional base level groundwater table below a threshold accommodation rate nonzero no continuous peats accumulate due to falling or low groundwater table sedimentary bypass and extensive erosion by fluvial channels this is typical of upper highstand lowstand fan and basal lowstand wedge systems tracts higher accommodation rates provide relatively stable conditions with rising groundwater tables mires initiate and copyright 1997 the american association of petroleum geologists all rights reserved 1manuscript received september 7 1995 revised manuscript received november 25 1996 final acceptance may 5 1997 2exxon production research company 3120 buffalo speedway houston texas 77096 3exxon production research company 3120 buffalo speedway houston texas 77096 present address conoco inc p o box 2197 houston texas 77252 we benefited from the input and assistance of many people of special assistance were the teams involved in collaborative studies with esso australia and esso malaysia p moore m sloan j emmett b burns a partridge s creaney hanif hussein r hill r lovell and m feeley we also thank the rock springs team r beauboeuf p mclaughlin w devlin a carroll y y chen g grabowski jr k miskell gerhardt m farley r webster and j schwalbach group members d curry and j yeakel were always helpful we also enjoyed and profited from many discussions of these concepts with our colleagues outside exxon c diessel r boyd k shanley b zaitlin p mccabe m hendricks a cohen and m kirschbaum we thank the reviewers of company reports whose careful comments on several generations of this work improved it s creaney m feeley j van wagoner f wehr j yeakel and a young f weber and j zullig provided extensive management support k linke translated our sketches into the fine figures herein we value all the help

floral evidence for high summer temperatures in southern scandinavia during 15 11 cal ka bp abstract the global climate transition from the lateglacial to the early holocene is dominated by a rapid warming trend driven by an increase in orbital summer insolation over high northern latitudes and related feedbacks the warming trend was interrupted by several abrupt shifts between colder stadial and warmer interstadial climate states following instabilities of the atlantic meridional overturning circulation amoc in response to rapidly melting ice sheets the sequence of abrupt shifts between extreme climate states had profound impacts on ecosystems which make it challenging to reliably quantify state variables like july temperatures within a non analogue climate envelope for europe there is increasing albeit inconclusive evidence for higher stadial summer temperatures than initially thought here we present a comprehensive floral compilation of plant macrofossils from lake sediment cores of 15 sites from s scandinavia covering the period 15 to 11 ka bp we find evidence for a continued presence of plant species indicating high july temperatures throughout the last deglaciation the presence of hemiboreal plants in close vicinity to the southern margin of the fennoscandian ice sheet implies a strong thermal summer forcing for the rapid ice sheet melt consistent with some recent studies we do not find evidence for a general stadial summer cooling which indicates that other reasons than summer temperatures caused drastic setbacks in proxy signals possibly driven by extreme winter cooling and or shorter warm seasons

the devensian weichselian lateglacial palaeoenvironmental record from gransmoor east yorkshire england a contribution to the north atlantic seaboard programme of igcp 253 termination of the pleistocene abstract palynological and coleopteran data are described from a section through late devensian weichselian deposits at gransmoor east yorkshire england the pollen evidence shows that following an initial open habitat episode first juniperus scrub and later betula woodland became established in the area during the lateglacial interstadial this woodland was replaced during the loch lomond younger dryas stadial by a predominatly herbaceous flora with arctic alpine steppe and halophytic elements the coleopteran evidence indicates a similar local environment and that the thermal maximum of the interstadial when mean july temperatures may well have exceeded 18 c occurred prior to the deposition of the earliest polleniferous sediments by the time of the juniperus expansion summer temperatures had fallen by 2 4 c to levels comparable with those of the present day a further temperature decline followed the expansion of betula during the later interstadial and another fall occurred at the lateglacial interstadial loch lomond stadial boundary during the loch lomond stadial mean july temperatures of 9 11 c are implied with winter temperatures as low as 15 to 20 c collectively the evidence reemphasises the point that for the first 1000 years or so of the lateglacial interstadial there was a disequilibrium between the palynological and coleopteran records in terms of climatic signal during the later interstadial however a closer relationship is apparent between both proxy data sources of particular significance in this respect is the fluctuation in reconstructed summer and winter temperatures and a rise and subsequent fall in betula pollen frequencies this may be the correlative of one of the pre younger dryas climatic oscillations recorded in other proxy data sources including palynological records from britain and eastern canada oxygen isotope traces from swiss lake sediments isotopic and electrical conductivity profiles from the greenland ice sheet and diatom and foraminiferal records in cores from the norwegian sea and the north atlantic ocean

is there a single surge mechanism contrasts in dynamics between glacier surges in svalbard and other regions 1 during the 1990s monacobreen a 40 km long tidewater glacier in svalbard underwent a major surge we mapped the surge dynamics using ers synthetic aperture radar images differential dual azimuth interferometry and intensity correlation tracking a series of 11 three dimensional 3 d velocity maps covering the period 1991 1997 show a months long initiation and years long termination to the surge with no indication of a surge front travelling downglacier during the surge the front of the glacier advanced 2 km the velocity and derived strain rate increased by more than an order of magnitude and maximum ice flow rates measured during 1994 were 5 m d 1 the spatial pattern of both velocity and strain rate was remarkably consistent and must therefore be controlled by spatially fixed processes operating at the glacier bed we combine these results with those published in the literature to construct a typical svalbard glacier surge cycle and compare this to surge dynamics of glaciers from other cluster regions especially those of variegated glacier in alaska the strong contrast in dynamics suggests that there exist at least two distinct surge mechanisms

sediment deformation structures and the palaeotectonic analysis of sedimentary basins with a case study from the carboniferous of northern england

reconstruction of a lateglacial younger dryas mountain ice field in sutherland northwestern scotland and its palaeoclimatic implications quaternary geomorphological and geological mapping of a large area 1800 km2 in the northwestern scottish highlands has led to the reconstruction of a coherent mountain ice field approximately 45 km long and 30 km wide at its maximum extent this west sutherland ice field covered an area of 350 km2 and had a mean equilibrium line altitude of 334 m assuming that the outlet glaciers all reached their maxima simultaneously numerical dating strongly suggests a younger dryas 12 9 11 7 ka age of the mapped limits of this mountain ice field this study also shows that the area of northwestern scotland covered by younger dryas glaciers was five times larger than previously thought palaeo temperature estimates obtained from chironomid and beetle assemblages elsewhere have been used to reconstruct palaeo precipitation during the younger dryas for west sutherland using a previously published global empirical dataset annual precipitation of 2344 248 mm a 1 at sea level is inferred from our new palaeo glacier reconstruction suggesting slightly wetter conditions compared to the present day these figures are in good agreement with those reconstructed for other parts of the scottish highlands and islands and this may indicate a marked w e palaeo precipitation gradient during the younger dryas this paper goes on to discuss the wider validity of palaeo climatic reconstructions from inferred palaeo glacier geometries and presents a number of possible scottish lateglacial climate scenarios which warrant further testing copyright 2010 john wiley sons ltd

a late middle pleistocene temperate periglacial temperate sequence oxygen isotope stages 7 5e near marsworth buckinghamshire uk abstract river channel and colluvial deposits near marsworth buckinghamshire record a temperate periglacial temperate sequence during the late middle pleistocene the deposits of a lower channel contain tufa clasts bearing leaf impressions that include acer sp and sorbus aucuparia and containing temperate arboreal pollen attributed to ash dominated woodland the tufa probably formed at the mouth of a limestone spring before being redeposited in a small river whose deposits contain plant remains mollusca coleoptera ostracoda and vertebrate bones of temperate affinities the sediments sedimentary structures and limited biological remains above the lower channel deposits indicate that fluvial deposition preceded climatic cooling into periglacial conditions fluvial deposition recurred during a later temperate episode as shown by the mammalian bone assemblage in stratigraphically higher channel deposits the upper channel deposits are confidently attributed to oxygen isotope sub stage 5e ipswichian on the basis of their vertebrate remains however the age of the lower channel deposits is less clear the mammalian and coleopteran remains in the lower channel strongly suggest correlation with oxygen isotope stage 7 on the basis of their similarities to other sites whose stratigraphy is better known and the clear difference of the lower channel assemblage from well established faunas of ipswichian or any other age by contrast u th dating of the tufa clasts suggests an age post 160 ka bp while aile ile ratios on mollusca point to an ipswichian age and younger four ways of interpreting this age discrepancy are considered the preferred one correlating the lower channel deposits with oxygen isotope stage 7

on balanced and unbalanced accommodation peat accumulation ratios in the cretaceous coals from gates formation western canada and their sequence stratigraphic significance coal composition was investigated by means of photometric and maceral analyses on closely spaced lithotype based strip samples over the full thickness of several paralic coal seams from the cretaceous gates formation of the western canadian sedimentary basin the aim of this investigation was to test various methods of identifying accommodation trends in coal and use them to refine sequence stratigraphic interpretation of continental sediments conventional sequence stratigraphy derives its subdivisions and significant surfaces from the records left by relative sea level oscillations these records either do not project into the continental realm or are difficult to recognise in clastic non marine sediments paralic coal seams have been selected to study this problem because they are not entirely removed from marine influence and compared with most inorganic deposits coal has stored a greater wealth of information that can be analysed at a higher level of resolution the study has led to the identification of five new surfaces with chronostratigraphic potential in the sequence stratigraphic analysis of non marine sediments two of these surfaces called paludification surface pas and terrestrialisation surface tes occur at the bases of the investigated coal seams while two other surfaces referred to as non marine flooding surface nfs and give up transgressive surface guts form the tops of the coal the fifth and probably most important new surface called the accommodation reversal surface ars is independent of any particular facies and may either coincide with some of the other surfaces or occur separately the proportion of detrital minerals has been used as the chief discriminator between different mire types and accommodation trends other useful indicators of mire type and peat dispersal have been the proportions of sporinite and inertodetrinite as well as some derived maceral and or mineral ratios e g the groundwater influence index and the tissue preservation index isometamorphic variations of telovitrinite reflectance and fluorescence as well as their coefficients of variation were also found to contribute to the identification of cyclic shifts between balanced and unbalanced accommodation peat accumulation ratios some of these cycles which are backed up by clastic stratigraphy appear to correspond to the development of shallowing upward and deepening upward parasequences superimposed high frequency low amplitude perturbations in the coal cycles relate to smaller scale accommodation cycles of sub parasequence level not always recognised in non marine strata these sub parasequence coal cycles do not always continue the shallowing upward trend typical of conventional parasequences several coals were found to contain stacks of small scale cycles with upward increasing accommodation signatures either in their lower or upper halves or over the whole seam section

integrating human dimensions of arctic palaeoenvironmental science sead the strategic environmental archaeology database environmental change has a human dimension and has had so for at least the last 10 000 years the prehistoric impact of people on the arctic landscape has occasionally left visible traces such as house and field structures more often than not however the only evidence available is at the microscopic or geochemical level such as fossil insect and seed assemblages or changes in the physical and chemical properties of soils and sediments these records are the subject of sead a multidisciplinary database and software project currently underway at umea university sweden which aims to create an online database and set of tools for investigating these traces as part of an international research infrastructure for palaeoecology and environmental archaeology

weichselian upper pleniglacial environmental variability in north western europe reconstructed from terrestrial mollusc faunas and its relationship with the presence absence of human settlements abstract during the weichselian glaciation millennial timescale climatic changes are a major cause of environmental variability which influence the composition of large mammal fauna and the geographical distribution of human prehistoric populations nevertheless precise environmental contexts of archaeological artefacts may remain unknown due to an unclear stratigraphy and or to the bad preservation of paleoenvironmental proxies as pollen is badly preserved in glacial loess deposits a compilation of age constrained high resolution molluscan records is used to initiate the establishment of a canvas of millennial timescale spatial and temporal environmental changes in the european loess belt during the weichselian upper pleniglacial ca 37 20 ka to look for relationships with spatial distribution of human settlements in this study new terrestrial mollusc assemblages have been added to the database previously established for north western europe they strengthen the position of the limit between the two molluscan based biogeographical domains initially highlighted for north western europe a flat and poorly vegetated western domain extending around the channel and in belgium and a hilly domain with more diversified vegetation to the east the analysis of molluscan data shows the persistence of these two domains throughout alternations of loess deposition phases interstadial stadial transitions and stadial phases with phases of development and degradation of tundra gley horizon stadial interstadial transitions and interstadial phases the interpretation of malacofauna from both domains combined with associated pedological and sedimentological features climate modelling and comparisons with present tundra environments reveals a significant effect of both seasonality and snow cover along a longitudinal gradient between both domains but also between phases of loess deposition and phases of tundra gley development during interstadial phases the intense functioning of the active layer and the degradation of permafrost in north western europe led to more homogeneous environments which were less favourable for the diversity of both vegetation and terrestrial mollusc fauna presently uncertainties of numerical ages still preclude precise correlations of loess units and tundra gley horizons between different sites and with nonlocal prehistoric occupations however a first raw comparison of the molluscan data with spatial distributions of aurignacian gravettian and solutrean upper magdalenian lithic cultures reveals that the northern limit of the first two ones fits well with the south eastern border of the poorly vegetated western domain also characterised by well developed ice wedge networks during phases of permafrost installation later an important southward shift of human populations in western europe resulted from the extreme aridity of the last glacial maximum

influence of seasonality on glacier mass balance and implications for palaeoclimate reconstructions climates inferred from former glacier geometries in some areas exhibit discrepancies with regional palaeoclimates predicted by general circulation models gcms and modelling of palaeoecological data possibly as a consequence of their differing treatments of climatic seasonality since glacier based climate reconstructions potentially offer an important tool in the calibration of gcms which themselves need validation if used to predict future climate scenarios we attempt to resolve mismatches between these techniques by 1 investigating the influence of seasonality on glacier mass balance and 2 refining the methodology used for the derivation of glacier based palaeoclimates focussing on the younger dryas stadial glaciation of scotland northeast atlantic we show that sea ice amplified seasonality led to a significantly drier climate than has been suggested by glacier based interpretations this was characterised by a relatively short ablation season and the survival of a more substantial winter snowpack we suggest that if palaeoglaciological studies were to account for changes in seasonal temperature and precipitation variability their results would agree more closely with the cold arid northeast atlantic palaeoenvironment predicted by atmospheric modelling and northwest european pollen studies and would therefore provide more accurate constraints for gcm calibration

early holocene coastal environments and climate in southeast sweden a reconstruction based on macrofossils from submarine deposits early holocene coastal environments and climate in southeast sweden a reconstruction based on macrofossils from submarine deposits

chironomid inferred summer temperatures for the last glacial interglacial transition from a lake sediment sequence in muir park reservoir west central scotland lake sediments spanning the last glacial interglacial transition lgit ca 14 7 to 8 ka bp from muir park reservoir mpr in west central scotland were analysed for chironomids the site lies just outside the southern limit of a former glacier that advanced into the loch lomond basin during the loch lomond younger dryas stadial chironomid inferred mean july temperatures were derived using a modern norwegian calibration dataset three tephra layers constrain the sequence chronologically inferred temperatures decline from a high value early in the interstadial punctuated by two cold oscillations probably equivalent to gi 1d and gi 1b in the greenland ice core record and a warm oscillation equivalent to gi 1a immediately before the severe cooling at the start of the loch lomond stadial gs 1 when summer temperatures fell by about 5 c below the interstadial average summer temperatures fell by about 3 c below the interstadial average during gi 1d which is less severe than inferred from other chironomid records from eastern scotland and may reflect the influence of an oceanic continental gradient cooling during gi 1b was particularly strong at mpr when minimum temperatures were about the same as those reached during gi 1d unlike other sites investigated where gi 1d is usually between 1 and 2 c cooler than gi 1b

palaeoecology of a late allerod peat bed at godoy western norway a peat bed found under solifluction deposits on godoya island western norway accumulated during a few decades around 11 000 yr bp at the end of the allerod period of the late weichselian palaeoecological investigations showed a local vegetation succession on wet sand culminating in a mire community dominated by carex nigra periodic flooding brought in sand and silt which decreased as drainage was impeded sufficiently for standing water to develop the surrounding terrestrial vegetation was dominated by salix scrub with some open heath and alpine habitats nearby apart from two aquatic species the 29 insect taxa recorded are characteristic of alpine heaths plant litter under salix scrub and stream sides their remains together with the terrestrial plant macrofossils were washed into the mire from nearby because the fossils are locally derived the environmental reconstructions are of the actual conditions at godoy at ca 11 000 yr bp palaeotemperature estimates from beetles and plants are in agreement the coleopteran estimates mutual climatic range method suggest mean july temperatures of 10 13 c slightly cooler than today 13 5 and january temperatures between 1 and 10 c similar to or much colder than today summer temperature estimates from individual plant taxa indicate that temperatures during the allerod period were similar to today s but estimates from the reconstructed vegetation and timber line positions give estimates up to 3 5 cooler temperatures fell 2 5 7 5 c at the younger dryas this abrupt and severe cooling initiated the solifluction processes on godoya that buried the peat the godoy peat bed and its contained fossils provide a rare glimpse of allerod biota and environments at the local site scale

chironomidae insecta diptera succession in żabieniec bog and its palaeo lake central poland through the late weichselian and holocene abstract subfossil chironomidae assemblages were studied in a sediment sequence from abieniec bog in central poland the climate history and habitat changes in the palaeo lake were reconstructed from these assemblages currently no chironomid based climate calibration set is available from poland and so past mean july air temperatures were inferred from chironomid climate calibration data sets from norway russia and switzerland during the late weichselian the three calibration functions from these data sets provided similar temperature inferences but there was some divergence in the reconstructions for the younger dryas and holocene in the late pleniglacial inferred summer air temperature was relatively low 8 12 c and the lake was oligotrophic at about 16 5 ka bp temperature rapidly rose to 15 c and assemblage diversity substantially increased during the interstadial temperature stayed at this level in the younger dryas july air temperature was only 1 2 c lower than in the interstadial as inferred from the norwegian calibration data set whereas the russian and swiss calibration functions did not indicate any temperature decrease from the beginning of the holocene taxa typical of meso eutrophic conditions dominated there was an increased abundance of phytophilous species and the assemblage composition was also influenced by changes in water level palaeotemperature reconstructions differed in their values from 8 0 to 8 7 ka bp inferences based on the swiss and russian data sets indicated a cold oscillation while reconstructions based on the norwegian data set did not show any temperature decrease after 2 5 ka bp assemblage diversity and head capsule concentrations decreased in the last millennium semi terrestrial taxa dominated except from late medieval to early modern times when shallow water species reappeared

temperature gradients in northern europe during the last glacial holocene transition 14 914c kyr bp interpreted from coleopteran assemblages late glacial and early holocene climatic conditions have been reconstructed for northern europe using the mutual climatic range mcr palaeoclimate method based on fossil coleopteran assemblages altogether beetle faunas from 77 sites have been analysed ranging from ireland in the west to poland and finland in the east and mcr estimates calculated the results are plotted on 16 maps each representative of a selected time slice covering the period from 14 5 14c kyr bp to 9 0 14c kyr bp eight of the maps show the mcr estimates of tmax mean temperature of the warmest month derived from each site for which data are available while the remainder show estimated tmax isotherms interpolated from these values it can be demonstrated that at times the thermal climate was fairly uniform throughout the study area whereas at others temperature gradients were much steeper than they are in the region today there also appears to be a distinct contrast between cold periods when contours trended nw se and warmer periods when contours trend w e or even ne sw the pattern of climatic changes that emerges is shown to be very different from the traditional view that has been used up to now as a template for classifying late glacial climatic events on a wide even global scale the suddenness and intensity of changes in the thermal climate may have been partially responsible for an apparent lack of equilibrium between the flora and fauna of the time and the physical environment in which they lived 1998 john wiley sons ltd

the influence of half graben syn depositional tilting on thickness variation and seam splitting in the brunner coal measures new zealand abstract the brunner coal measures buller coalfield new zealand comprise a fluviatile sequence of eocene age that is generally 30 100 m thick the sequence rests on basement and is dominated by coarse to granular very coarse sandstone the measures contain one mineable coal seam the buller seam member that is laterally extensive and up to 20 m thick it is characterized by simple splitting with a thin upper split a thick lower split and a split separation of up to 30 50 m locally the buller seam member exhibits splitting to form numerous thin seams areas of shale out comprise thin linear belts between areas of thick coal with a low ash yield the coincidence of faults and maximum thickness of seam isopachs indicates that the thickness and splitting characteristics of the buller seam member were largely controlled by syn depositional faulting and tilting of small half graben blocks thickness variation in basal sequences is primarily due to syn depositional faulting syn depositional tilting of fault blocks also influenced the migration of river channels and hence the stacking and distribution of sandstone and locally thick mudstone units overlying coal

direct comparison of uk temperatures and greenland snow accumulation rates 15000 12000 yr ago a palaeotemperature record based on fossil coleopteran evidence and dated by accelerator mass spectroscopy ams 14c determinations on plant macrofossils has been obtained for the last glacial interglacial transition from the site of gransmoor in eastern england calibration of the radiocarbon measurements enabled a direct comparison to be made between this palaeotemperature curve and the snow accumulation record from the gisp 2 greenland ice core the similarity between the two data sets suggests a degree of correspondence in the pattern and timing of climatic change in greenland and the british isles at the end of the last cold stage

a compilation of western european terrestrial records 60 8 ka bp towards an understanding of latitudinal climatic gradients terrestrial records of past climatic conditions such as lake sediments and speleothems provide data of great importance for understanding environmental changes however unlike marine and ice core records terrestrial palaeodata are often not available in databases or in a format that is easily accessible to the non specialist as a consequence many excellent terrestrial records are unknown to the broader palaeoclimate community and are not included in compilations comparisons or modelling exercises here we present a compilation of western european terrestrial palaeo records covering entirely or partially the 60 8 ka intimate time period the compilation contains 56 natural archives including lake records speleothems ice cores and terrestrial proxies in marine records the compilation is limited to include records of high temporal resolution and or records that provide climate proxies or quantitative reconstructions of environmental parameters such as temperature or precipitation and that are of relevance and interest to a broader community we briefly review the different types of terrestrial archives their respective proxies their interpretation and their application for palaeoclimatic reconstructions we also discuss the importance of independent chronologies and the issue of record synchronization the aim of this exercise is to provide the wider palaeo community with a consistent compilation of high quality terrestrial records to facilitate model data comparisons and to identify key areas of interest for future investigations we use the compilation to investigate western european latitudinal climate gradients during the deglacial period and despite of poorly constrained chronologies for the older records we summarize the main results obtained from nw and sw european terrestrial records before the lgm

dips ramps and rolls evidence for paleotopographic and syn depositional fault control on the western kentucky no 4 coal bed tradewater formation bolsovian illinois basin abstract the western kentucky no 4 coal is a high volatile b to high volatile c bituminous coal that has been heavily mined along the southern margin of the western kentucky coal field the seam has a reputation for rolling floor elevation elongate trends of floor depressions are referred to as dips and rolls by miners some are relatively narrow and straight to slightly curvilinear in plan view with generally symmetric to slightly asymmetric cross sections others are broader and asymmetric in section with sharp dips on one limb and gradual ramp like dips on the other some limbs change laterally from gradual dip to sharp dip to offset of the coal lateral changes in the rate of floor elevation dip are often associated with changes in coal thickness and in underground mines changes in floor elevation are sometimes associated with roof falls and haulage problems in order to test if coal thickness changes within floor depressions were associated with changes in palynology petrography and coal quality the coal was sampled at a surface mine across a broad ramp like depression that showed down dip coal thickening increment samples of coal from a thick 150 cm down ramp and thinner 127 cm up ramp position at one surface mine correlate well between sample sites a distance of 60 m except for a single increment the anomalous increment 31 cm in the lower middle part of the thick coal bed contained 20 more lycospora orbicula spores the rolling floor elevations noted in the study mines are inferred to have been formed as a result of pre peat paleotopographic depressions syn depositional faulting fault controlled pre peat paleotopography and from compaction beneath post depositional channels and slumps although the association of thick coal with linear trends and inferred faults has been used in other basins to infer syn depositional faulting changes in palynology within increment samples of the seam along a structural ramp in this study provide subtle evidence of faulting within a specific increment of the coal itself the sudden increase in l orbicula produced by paralycopodites in a single increment of a down ramp sample of the western kentucky no 4 coal records the reestablishment of a rheotrophic mire following a sudden change in edaphic conditions paralycopodites was a colonizing lycopod which in this case became locally abundant after the peat was well established along a fault with obvious growth during peat accumulation because many coal mire plants were susceptible to sudden edaphic changes as might accompany faulting or flooding changes in palynology would be expected in coals affected by syn depositional faulting

geochronology of betula extensions in pollen diagrams of alpine late glacial lake deposits a case study of the late glacial deposits of the gasserplatz soil archives vorarlberg austria pollen diagrams of alpine late glacial calcareous lake deposits show several extensions of betula the geochronology of these extensions cannot be based on radiocarbon dating due to reservoir effects of such lakes on the radiocarbon ages a robust geochronology can be based on the oxygen isotope stratigraphy additionally recognition of 12 920 calbp lst in the sediment cores provides a secure time marker the combined results of pollen macro remains and stable isotope analyses of the gasserplatz cores point to a correlation of the betula extensions with the oscillations in the oxygen isotope curve and are related to global climatic oscillations this is sustained by the correlation of the gasserplatz isotope oscillations with the oscillations as registered in the greenland ice cores comparison of the results of the gasserplatz cores with the results of similar alpine lake deposits makes clear that the fluctuations in the betula curve are not a local but a regional phenomenon

an event stratigraphy for the last termination in the north atlantic region based on the greenland ice core record a proposal by the intimate group it is suggested that the grip greenland ice core should constitute the stratotype for the last termination based on the oxygen isotope signal in that core a new event stratigraphy spanning the time interval from ca 22 0 to 11 5 k grip yr bp ca 19 0 10 0 k 14 c yr bp is proposed for the north atlantic region this covers the period from the last glacial maximum through termination 1 of the deep ocean record to the pleistocene holocene boundary and encompasses the last glacial late glacial of the traditional northwest european stratigraphy the isotopic record for this period is divided into two stadial episodes greenland stadials 1 gs 1 and 2 gs 2 and two interstadial events greenland interstadials 1 gi 1 and 2 gi 2 in addition gi 1 and gs 2 are further subdivided into shorter episodes the event stratigraphy is equally applicable to ice core marine and terrestrial records and is considered to be a more appropriate classificatory scheme than the terrestrially based radiocarbon dated chronostratigraphy that has been used hitherto 1998 john wiley sons ltd

changes in hydrocarbon maturity indices with coal rank and type buller coalfield new zealand abstract the buller coalfield south island new zealand is an inverted late paleogene basin that contains middle eocene bituminous coals which exhibit considerable variation in both coal rank across basin and coal type in seam twenty two fractionated bitumen extracts of brunner coal measures coal samples from 12 drillholes were analyzed by gc and gc ms to characterize the effect of coal rank and type on conventional hydrocarbon maturity indices at the beginning and end of the oil window 0 56 1 26 ro max the carbon preference index pristane phytane and isoprenoid n alkane ratios evolve throughout the high volatile bituminous b rank stage while other biomarker ratios 18 h 22 29 30 trisnorneohopane 17 h 22 29 30 trisnorhopane ts tm 18 h 21 h 30 norneohopane c 29 ts 17 h 21 h 30 norhopane and c 30 diahopane hopane do not show appreciable change in value until medium volatile bituminous rank various aromatic based ratios appear to be more effective in delineating rank throughout the entire oil window in particular the methylphenanthrene index and vitrinite reflectance are positively correlated over the entire bituminous rank range however subtle changes in depositional conditions variable coal type complicate these rank estimates within a given coal seam variation in cpi isoprenoid n alkane and hopane sterane ratios appear to be related to the hydrogen content of the coal while the homohopane index and the oleanane hopane ratio covary with sulfur content as with depressed vitrinite reflectance values mpi is similarly lowered in the perhydrous samples the mechanisms that control these hydrocarbon parameters during deposition and diagenesis are complex and convoluted however changes in bacterial activity and community with marine incursion appear to play an important role due to these anomalies none of the hydrocarbon maturity indices calculated can be singularly used to constrain coal rank

peat accumulation on a drowned coastal braidplain the mullins coal upper carboniferous sydney basin nova scotia abstract the mullins coal lies within the braided fluvial south bar formation the lateral extent 15 km and thickness 2 m of the coal suggest that controls for peat accumulation were allogenic marine inundation of the distal braidplain as indicated by the high sulphur content of the coal and the occurrence of agglutinated foraminifera in associated shales caused ponding of freshwater near maximum marine transgression with accumulation of thick paralic peat across a stable platform of sandy fluvial sediments highstand parasequences with thin capping coals were subsequently incised beneath a sequence boundary as the braidplain readvanced the mullins coal thins and splits in association with muddy bayfill deposits eastward towards the glace bay syncline a long lived palaeotopographic element related to fault bounded basement blocks although relative sea level change controlled the stratigraphic position of the precursor peats differential tectonic subsidence and or compaction modified their extent thickness and quality

a multiproxy study of younger dryas and early holocene climatic conditions from the grabia river paleo oxbow lake central poland abstract a multi proxy reconstruction of water depth temperature and precipitation inferred from cladocera chironomidae and pollen assemblages has been obtained from wierczyna paleo oxbow central poland during the younger dryas yd and early holocene results suggest that the yd was relatively cold and comprised two main phases the first ca 12 500 12 000 cal yrs bp is characterized by a continental climatic regime and a decrease in winter temperatures and precipitation but an increase in spring summer precipitation the second phase ca 12 000 11 500 cal yrs bp was more mild with a variable continental climate an increase in summer and winter temperature a lengthening of the growing season and increased annual precipitation the reconstructed water level generally follows changes in spring and summer precipitation and length of growing season the frequency and timing of hydroclimatic oscillations at wierczyna show strong similarities to records from other sites in europe this confirms that oxbows and valley mire ecosystems respond to rapid climate change during the yd and early holocene this study therefore brings new insights into the effects of climate changes on river environments especially during the yd we also discuss the limitations of water depth temperature and precipitation reconstructions inferred from the studied biotic assemblages

regression coefficients of thermal gradients in northwestern europe during the last glacial holocene transition using beetle mcr data palaeotemperature estimates obtained from 74 sites in northern europe and collectively spanning approximately the last 45 000 yr radiocarbon time scale have been compiled as a major component o

paleoceanographic reconstructions of surface ocean conditions in the greenland iceland and norwegian seas through the last 14 ka based on diatoms prior reconstructions of the last glacial maximum and the holocene did not include detailed paleoclimate data from the greenland iceland and norwegian gin seas which cover sensitive areas for oceanographic boundaries sea ice distribution and deep water formation in order to fill this gap we studied nine well dated sediment cores from this area and reconstructed the paleoceanographic conditions of the surface gin seas at 2000 year intervals since 13 400 bp based on the diatom record results show that a n s extending sea ice free corridor had opened along norway already at 13 400 bp indicating a northward flow of a branch of the north atlantic drift possibly caused by a change in the jet stream flow due to the decreased height of the north american ice sheet a major change of climatic conditions occurred over the gin seas as the insolation anomaly reached its maximum around 9000 bp when the sea ice cover and the oceanic fronts retreated to a northwesterly position along greenland and the ocean temperatures rose the first half of the holocene is recorded as the warmest period during the last 13 400 bp in the gin seas the duration of this climatic optimum decreased both toward the north and toward the margins of the area the second half of the holocene is characterized by a cooling trend in step with the decreasing insolation these results support the proposal of imbrie et al 1992 that the gin seas region acts as an initial responder to insolation changes