holocene palaeoclimates from peat stratigraphy macrofossil proxy climate records from three oceanic raised bogs in england and ireland quantified analyses of plant macrofossil remains have been made from three profiles of peat from raised bogs spanning a distance of 425 km from western ireland to northern england the reconstructed vegetation of each profile is related to changing bog surface wetness bsw and since the bogs are ombrotrophic these bsw changes are interpreted in terms of changing climate using age depth models based on a total of 49 radiocarbon dates a number of wetter and drier phases are identified and phase shifts to wetter and or cooler climates are defined prominent coincident changes to wetter conditions are dated in at least two of the profiles to ca 4400 4000 1750 1400 and 1000 cal bp and in all three profiles at 3200 2750 2350 2250 and around 700 cal bp these phases are related to proxy climate changes in other terrestrial data sets from northwest europe and a broad degree of synchroneity is demonstrated

vegetation climate and environmental history of the last 4500 years at lake shkodra albania montenegro three parallel overlapping cores have been taken in the albanian side of lake shkodra albania montenegro the chronological frame of the record spanning approximately the last 4500 years has been assessed using four radiocarbon dates and four well known tephra layers of italian volcanoes multidisciplinary analyses turned out to be decisive to understand environmental climatic changes and human impact here we focus on palynology the humidity at shkodra was always enough to allow the developing of a luxuriant arboreal vegetation the pollen percentage diagram does not record important changes in terrestrial plants percentages arboreal pollen ap shows only a rather slight decrease with natural forests replaced by intensive cultivation of chestnut and walnut in the last seven eight centuries the rather minimal changes in composition and dominance are because of the fact that the pollen rain comes from different vegetation belts from the mediterranean to the alpine one two major periods of hu

compilation of non annually resolved holocene proxy climate records stacked holocene peatland palaeo water table reconstructions from northern britain abstract the number and range of holocene palaeoclimate reconstructions from various regions of the world have increased dramatically over the last decade the data density for many regions and proxies now offers the potential of robust regional scale reconstructions that avoid the problems of records from individual sites and improve communication between palaeoclimate subdisciplines and climate modellers however there are problems with chronological uncertainties and quantification of proxies which make compilation of multiple records difficult here we explore a stacking and tuning approach to the derivation of regional records from peatland climate proxies to test its applicability to non annually resolved terrestrial records twelve individual records from northern britain based on water table reconstructions from testate amoebae analysis were divided into four regions records were detrended normalised and compared within regions to identify clear correlative events the original chronologies of the records were tuned using both these events and independent age markers the stacked record for northern britain indicates pronounced changes to wet conditions at 3600 2760 and 1600 cal yr bp with more minor changes at 3060 2050 1260 860 550 and 260 cal yr bp the main wet phases are highly correlated with mid european lake highstands wider north atlantic climate change inferred from ocean and ice core records and solar variability tuning and stacking of non annual terrestrial palaeoclimate records is a new approach to the compilation and reconciliation of individual records within coherent climatic regions and provides a tool for upscaling of palaeoclimate records for climate model data comparisons

major features and forcing of high latitude northern hemisphere atmospheric circulation using a 110 000 year long glaciochemical series the greenland ice sheet project 2 glaciochemical series sodium potassium ammonium calcium magnesium sulfate nitrate and chloride provides a unique view of the chemistry of the atmosphere and the history of atmospheric circulation over both the high latitudes and mid low latitudes of the northern hemisphere interpretation of this record reveals a diverse array of environmental signatures that include the documentation of anthropogenically derived pollutants volcanic and biomass burning events storminess over marine surfaces continental aridity and biogenic source strength plus information related to the controls on both high and low frequency climate events of the last 110 000 years climate forcings investigated include changes in insolation of the order of the major orbital cycles that control the long term behavior of atmospheric circulation patterns through changes in ice volume sea level events such as the heinrich events massive discharges of icebergs first identified in the marine record that are found to operate on a 6100 year cycle due largely to the lagged response of ice sheets to changes in insolation and consequent glacier dynamics and rapid climate change events massive reorganizations of atmospheric circulation that are demonstrated to operate on 1450 year cycles changes in insolation and associated positive feedbacks related to ice sheets may assist in explaining favorable time periods and controls on the amplitude of massive rapid climate change events explanation for the exact timing and global synchroneity of these events is however more complicated preliminary evidence points to possible solar variability climate associations for these events and perhaps others that are embedded in our ice core derived atmospheric circulation records

persistent solar influence on north atlantic climate during the holocene surface winds and surface ocean hydrography in the subpolar north atlantic appear to have been influenced by variations in solar output through the entire holocene the evidence comes from a close correlation between inferred changes in production rates of the cosmogenic nuclides carbon 14 and beryllium 10 and centennial to millennial time scale changes in proxies of drift ice measured in deep sea sediment cores a solar forcing mechanism therefore may underlie at least the holocene segment of the north atlantic9s 1500 year cycle the surface hydrographic changes may have affected production of north atlantic deep water potentially providing an additional mechanism for amplifying the solar signals and transmitting them globally

proxy records of climate change in the uk over the last two millennia documented change and sedimentary records from lakes and bogs this project of collaborative research project ha of the nerc tigger programme terrestrial initiative in global geological environmental research into the climatic history of the late holocene used a variety of techniques both tested and experimental on carefully chosen sites in lowland and upland environments to derive high quality proxy records of climatic change over the last 2000 years the methodology involved the use of high resolution analyses diatoms cladocera chironomids ostracods magnetics pollen macrofossils humification lipid biomarkers and stable isotopes of the stratigraphy of well dated ams and conventional 14 c 210 pb pollen tephra scp spheroidal carbonaceous particles cores from a remote montane lake and lowland lakes and from a montane blanket and a lowland raised bog linked to historical records of climate change this paper reviews some of the major results obtained both in the magnitude synchroneity and periodicity of change especially during the little ice age and in the evaluation of the various techniques used the fact that such techniques can be validated and calibrated against a known climatic signal in the recent past allows for better interpretation of changes in the more distant past

holocene climate variability as reflected by mid european lake level fluctuations and its probable impact on prehistoric human settlements abstract a data set of 180 radiocarbon tree ring and archaeological dates obtained from sediment sequences of 26 lakes in the jura mountains the northern french pre alps and the swiss plateau was used to construct a holocene mid european lake level record the dates do not indicate a random distribution over the holocene but form clusters suggesting an alternation of lower and higher climatically driven lake level phases they provide evidence of a rather unstable holocene climate punctuated by 15 phases of higher lake level 11 250 11 050 10 300 10 000 9550 9150 8300 8050 7550 7250 6350 5900 5650 5200 4850 4800 4150 3950 3500 3100 2750 2350 1800 1700 1300 1100 750 650 cal bp and after 1394 ad a comparison of this mid european lake level record with the gisp2 polar circulation index pci record the north atlantic ice rafting debris ird events and the 14 c record suggests teleconnections in a complex cryosphere ocean atmosphere system correlations between the gisp2 pci the mid european lake level the north atlantic ird and the residual 14 c records suggest that changes in the solar activity played a major role in holocene climate oscillations over the north atlantic area

age geochemistry and distribution of the mid holocene hekla s kebister tephra the middle holocene hekla s kebister tephra originates in the hekla volcanic system on sw iceland the distal distribution of the tephra includes the faroe islands shetland and central sweden indicating a main dispersal towards the east the chemical composition of the tephra follows the pattern of other major eruptions of hekla and ratios between selected oxides may in some cases allow separation from other major holocene tephras from hekla tephra from the plinian phase dominates in eastern sites while tephra also from later phases is found in the faroe sites wiggle matching of radiocarbon dates around the tephra in a swedish peat bog suggests an age around 3720 cal yr bp 3750 3700 cal yr bp which is in accordance with previous attempts to date this tephra this is within a period with significant climate changes in nw europe and opens possibilities for exact comparisons of peat and lake sediment records from different geographical areas

replicated proxy climate signals over the last 2000 yr from two distant uk peat bogs new evidence for regional palaeoclimate teleconnections ombrotrophic peat is an established source of proxy climate data but previous records have been produced by different methods and have been difficult to compare high resolution plant macrofossil analysis has been applied to a lowland raised bog at fallahogy northern ireland and a montane blanket bog moine mhor in the cairngorms scotland although the bogs are 300 km apart and differ floristically the results demonstrate parallel responses to climatic forcing especially that of the little ice age this approach provides a powerful tool for reconstructing proxy climate records wherever suitable peat deposits exist in contrast to the ocean and ice core records these proxies are from a terrestrial source and related to climate changes on land over most of the holocene

the climate of scotland over the last 5000 years inferred from multiproxy peatland records inter site correlations and regional variability the mid to late holocene climates of most of scotland have been reconstructed from seven peat bogs located across north south and east west geographical and climatological gradients the main techniques used for palaeoclimatic reconstruction were plant macrofossil colorimetric humification and testate amoebae analyses which were supported by a radiocarbon based chronology aided by markers such as tephra isochrons and recent rises in pine pollen and in spheroidal carbonaceous particles scps field stratigraphy was undertaken at each site in order to show that the changes detected within the peat profiles were replicable proxy climate records were reconstructed using detrended correspondence analysis dca of the plant macrofossil data and a mean water table depth transfer function on the testate amoebae data these reconstructions coupled with the humification data were standardised for each site and used to produce a composite record of bog surface wetness bsw from each site the results show coherent wet and dry phases over the last 5000 years and suggest regional differences in climate across scotland specifically between northern and southern scotland distinct climatic cycles are identified all of which record a millennial scale periodicity which can be correlated with previously identified marine and ice core holocene cycles the key role of the macrofossil remains of sphagnum imbricatum a taxon now extinct on many sites is discussed in relation to the identified climatic shifts

a 5500 year proxy climate and vegetation record from blanket mire at talla moss borders scotland a monolith of peat taken from an upland blanket mire at talla moss southern scotland was sub jected to peat humification and pollen analyses to produce both a proxy climate record and a vegetational history covering the last 5500 years while the peat showed little visible stratigraphy with no intimation of major peat humification changes colorimetric data indicate a markedly oscillatory climate record which is apparently largely independent of or out of phase with major vegetational changes the raw data imply particular wet shifts in climate at c 3455 bp c 2600 bp c 1930 bp c 1095 bp with a markedly wet or cool and wet episode commencing at c 540 bp these are central age estimates and should not be regarded as precise dates for the inferred climate shifts other wet shifts apparently date from c 3070 bp c 2265 bp and c 1700 bp although the first of these corresponds with pollen evidence for significant prehistoric human activity in the locality spectral analysis of the peat h

solar forcing of climatic change during the mid holocene indications from raised bogs in the netherlands two cores of mid holocene raised bog deposits from the netherlands were 14 c wiggle match dated 14 c as a proxy for changes in solar activity is validated this paper adds to the increasing body of evidence that solar variability forced climatic changes during the holocene 14 c wiggle match dating mid holocene wet shifts

mire development pathways and palaeoclimatic records from a full holocene peat archive at walton moss cumbria england plant macrofossil data have been used to identify the successive mire communities occupying both central and marginal locations in the walton moss peatland complex during the last 10 500 years the reconstructed pathways of mire development indicate that early holocene fen and fen carr communities were succeeded by species indicative of deep mire water tables and oligotrophic conditions the character of the fen bog transition fbt is compared with similar records of peatland development from britain and scandinavia and with independent climate data for the early holocene the pseudohochmoor of central europe is suggested as an approximate modern analogue for the dry pioneer oligotrophic mire type and alternative explanations for its presence are explored the first major increase in ombrotrophic sphagna occurred at c 7800 cal bp overlying sphagnum peats provide a continuous record of climate change inferred from fluctuations in raised mire surface wetness the proxy palaeoclimate record reconstr

pyloniid stratigraphy a new tool to date tropical radiolarian ooze from the central tropical indian ocean pyloniid stratigraphy a faunal abundance variation stratigraphic tool similar to cycladophora davisiana stratigraphy employed at high latitudes is found to work well for tropical radiolarian ooze the relationship between the spatial distribution of 25 modern radiolarian groups in surface sediments and monsoonal surface salinity from the central indian ocean is analyzed among them pyloniids exhibit the potential to serve in the same way as the c davisiana stratigraphy down core temporal variation of pyloniids in a sediment core is compared with i the sum of the earth s orbital eccentricity axial tilt and precession etp ii solar insolation at the core site 8 s and 65 n and iii the specmap 18o stratigraphy the multi taper mtm spectral analysis of pyloniids for the last 485 ka in a core aas 2 3 reveals significant climatic cycles at the eccentricity 100 ka tilt 41 ka and precession 23 ka bands cross spectral analyses suggest coherent 90 pyloniid cycles lag both the etp and june insolation 65 n by 9 ka at 100 ka eccentricity and are almost 2 ka in phase with 41 ka tilt and 23 ka precession cycles coherent pyloniid cycles lag specmap 18o by 14 ka at 41 ka tilt and 6 ka at 23 ka precession while they lag insolation at the core site by 7 ka at 100 ka lead 18 ka at 41 ka and show in phase relation with 23 ka cycles marginal lead of 10 ka by etp and insolation over pyloniids at 100 ka eccentricity and in phase relation at 41 ka tilt and 23 ka precession cycles suggest pyloniids variation could be used as a tool to derive age models in tropical radiolarian ooze during the late neogene quaternary

the fluvial record of climate change fluvial landforms and sediments can be used to reconstruct past hydrological conditions over different time scales once allowance has been made for tectonic base level and human complications field stratigraphic evidence is explored here at three time scales the later pleistocene the holocene and the historical and instrumental period new data from a range of field studies demonstrate that croll milankovitch forcing dansgaard oeschger and heinrich events enhanced monsoon circulation millennial to centennial scale climate variability within the holocene probably associated with solar forcing and deep ocean circulation and flood event variability in recent centuries can all be discerned in the fluvial record although very significant advances have been made in river system and climate change research in recent years the potential of fluvial palaeohydrology has yet to be fully realized to the detriment of climatology public health resource management and river engineering

a 2800 year palaeoclimatic record from tore hill moss strathspey scotland the need for a multi proxy approach to peat based climate reconstructions analyses of plant macrofossils testate amoebae and humification have been carried out on a 2800 year core from tore hill moss a raised bog in the strathspey region of scotland all three analyses were carried out at the same 4 cm intervals allowing exact correlation and the core was dated by nine accelerator mass spectrometry radiocarbon dates and the glen garry tephra layer the results have been combined and compared to present a bog surface wetness bsw record within which the limitations of each proxy method can be assessed and this has highlighted the advantages of a combined rather than a single proxy approach significant wet shifts are recorded at ca cal 560 bc 60 bc ad 430 ad 570 ad 700 ad 1090 and ad 1640 significant shifts to drier periods are also suggested ca cal ad 220 ad 500 and ad 820 some of the recorded shifts and phases are related to phases of wetter and drier climate such as the sub boreal sub atlantic transition the dark age deterioration and the romano british warm period the dark ages are notable as a period of rapid peat accumulation and frequent water table fluctuations time series analysis revealed a significant wet shift cycle of 560 years from the testate amoebae data

a sensitive high resolution record of late holocene climatic change from a raised bog in northern england proxy climatic data in the form of plant macrofossils have been analysed from a 5 m core from bolton fell moss cumbria uk detailed analysis of peat from the upper 50 cm of this core is used to demonstrate a strong correlation between changes in the relative proportion of taxa and known climatic changes over the last 1000 years the record of changes in bog vegetation contained within the peat profile is used to reconstruct changes in bog surface wetness for the latter half of the holocene as bog surface wetness is directly controlled by the prevailing climatic conditions this reconstruction can be viewed as a proxy climate record twelve radiocarbon age estimates on the 5m core suggest that between 50 and 500 cm peat accumulated at a relatively constant rate of 12 4 yr cm 1 the regular sampling intervals thus provide a time series of past bog surface wetness spectral analyses of this series indicates that wetness changes are cyclic with a ca 800 year periodicity

replicability and variability of the recent macrofossil and proxy climate record from raised bogs field stratigraphy and macrofossil data from bolton fell moss and walton moss cumbria england replication of results is a basic tenet of science but in palaeoecology this is very time consuming and the signal is subject to noise the derivation of proxy climate signals from ombrotrophic peat was carried out originally using samples from open peat faces where the stratigraphic relationships could be easily observed now that such sections are rare and often degraded there is a need to demonstrate that data can be replicated from core profiles ten short cores taken from two adjacent bogs have been analysed for macrofossils and show a coherent series of changes which are also similar to previous profiles from the same sites it is concluded that variation between profiles is slight and less than observations of present vegetation mosaics might suggest recommendations for a standard approach to fieldwork on raised bogs that emphasises the utility of subfossil pool layers are proposed and the need for a secure chronology is stressed 1998 john wiley sons ltd

paleohydrological records from peat profiles and speleothems in sutherland northwest scotland abstract paleohydrological changes during the late holocene are inferred from humification testate amoebae and pollen evidence from three blanket peat profiles in northwest scotland replicate peat humification records from the traligill basin share the same patterns of change for a 600 yr period of overlap between 1800 and 2400 cal yr b p the shared patterns inferred from samples with a resolution of 5 13 yr represent basinwide hydrological changes in a nearby but hydrologically separate area with caves beneath peat the luminescence emission wavelength measured in two speleothem samples correlated with the humification record in the overlying peat this correlation implies that speleothem luminescence emission wavelength depends primarily on decay rates in the soils from which drip waters are derived as long as there is no major change in soil or vegetation the peat and speleothem records from the cave site further correlate with the peat records from the traligill basin taken together the records thus represent a regional climatic signal peaks in surface wetness replicated in two or more records occur at ca 2300 2090 2030 1820 1600 and 1440 cal yr b p further peaks occur at 800 570 and 115 cal yr b p in the humification and stalagmite records that extend to the present day correlative changes have been observed not only in other peat records from scotland but also in ice accumulation at gisp2 these further correlations imply that precipitation regimes in scotland and greenland were in phase during the late holocene

all age depth models are wrong but how badly the uncertainty and error associated with fitted age depth models were investigated by fitting a range of models to sets of simulated radiocarbon dates based on varved sediments and comparing the modelled relationship with the varve timescale with large numbers of dates cubic smooth splines out perform other models with few dates no model reliably provides a good fit to reality and calculated confidence intervals are over optimistic c 2003 elsevier ltd all rights reserved

snapshots in time precise correlations of peat based proxy climate records in scotland using mid holocene tephras mid holocene tephra layers have been located and geochemically analysed from seven ombrotrophic bogs in scotland the tephras found in these scottish peats occur as stratigraphically discrete horizons not visible to the naked eye and originate from volcanic activity in iceland identifying and geochemically typing the tephra layers can enable precise correlations between sites on regional scales depending on the spatial extent of the airfall events dispersal of both the glen garry and hekla 4 tephras is excellent over scotland enabling snapshot views of the past at the time of these tephra depositions palaeoecological analyses have also been undertaken on these bogs providing detailed reconstructions of past changes in bog vegetation and surface wetness a proxy for past climates correlations between the ombrotrophic bogs at the time of the glen garry tephra revealed significant differences between the proxy climate records in the north and the south of scotland suggesting asynchronous changes between northern scotland and the rest of great britain

mid and late holocene climatic changes a test of periodicity and solar forcing in proxy climate data from blanket peat bogs a wide range of palaeoenvironmental evidence from the holocene has suggested periodicities in the earth s climate of 10s to 1000s of years identifying these millennial century and decadal periodicities and their impacts is critical in developing a fuller understanding of natural climate variability any solar induced climatic change needs to be distinguished from other causes of natural climate variability and from short term catastrophic events induced either by external or internal processes such events might themselves generate a periodicity or in combination with other forcing factors they may contribute towards a periodicity and so spuriously imply a universal and continuing periodicity in the climate record or they may resonate with a solar induced periodicity here evidence from peat records for periodicity in climate change over the mid to late holocene is reviewed and this is followed by a test of the replicability of claimed periodicities using blanket peat data covering the past 2000 yr from four sites in the british isles results suggest that the mires studied do go through phases of being responsive to periodic forcing factors with ca 200 ca 80 and 60 50 yr wavelengths reflected in some data sets however the patterns shown are not consistent this could be the result of local conditions at individual mires human impact sensitivity and vegetation succession or of changes in the strength or nature of global forcing factors assessing a solar mire link remains difficult because the century scale variations of the sun show different intervals between solar minima the durations of which are themselves unequal and because the proxy climate data sets from peat profiles may themselves not be dated with sufficient precision and or accuracy

a proxy record of late holocene climate change from may moss northeast england quantitative reconstruction of changes in mire surface wetness has been used to reconstruct proxy climate from an upland ombrotrophic blanket mire on the north york moors in northeast england may moss testate amoebae plant macrofossil and humification analyses were carried out for six peat profiles transfer functions are used to generate estimates of water table levels from the testate amoebae stratigraphy which complement the semi quantitative indications of changing surface wetness provided by plant macrofossil and humification analysis 14c dates provide the chronology for the stratigraphy differences were encountered between ams 14c dates on pure sphagnum remains and radiometric dates on bulk peat from the same horizon which perhaps arise from the heterogeneity of peat replicate palaeoecological analysis of adjacent cores identifies consistency within testate amoebae and plant macrofossil stratigraphies and reveals a strong agreement between the water table level proxies the record of hydrological changes at sites across may moss are in synchrony and so climate change is the most likely cause of the moisture fluctuations changes to a wetter or cooler climate were identified cal ad 260 540 ca ad 550 650 cal ad 670 980 ca ad 1350 1450 cal ad 1400 1620 and ca ad 1700 1800 periods with a drier or warmer climate precede all of these wet shifts with particularly dry periods between cal ad 650 860 and 690 980 and between cal ad 1290 1410 and 1400 1620 copyright 2001 john wiley sons ltd

regional climate change from peat stratigraphy for the mid to late holocene in central ireland at the millennial scale bog surface wetness bsw records show a clear holocene climate event stratigraphy with major phases comparable with other regional climate proxies such as chironomid inferred temperature records moving towards the centennial scale however and towards the limits of chronological certainty within the records regional differences are apparent which likely reflect the more heterogeneous precipitation patterns which occur on shorter timescales the bsw data presented in this paper are reconstructed from testate amoebae assemblages from central ireland and are compared with other regional records the results suggest that this region is in phase with the north of ireland in terms of timings and durations of climate change but the comparisons are less clear with a stacked and tuned record from northern britain that shows an apparent offset compared to the irish records this may reflect variations in past regional precipitation or be a function of the tuning and stacking process the broad phases of comparison between the irish records and the extension of the central irish record back to 6000 cal bp allow comparisons with low frequency temperature reconstructions from chironomids which also show a broad level of correlation with cooler temperatures relating to wetter bsw at centennial to millennial timescales

solar influences on holocene climatic changes illustrated by correlations between past lake level fluctuations and the atmospheric 14c record chronological correlations established at different time scales among the lake level fluctuations in the jura and french subalpine ranges glacier movements in the swiss and austrian alps and the atmospheric 14c record during the last 7 millennia show coincidences between lake level rises glacier advances and high 14c production and vice versa these correspondences suggest that the short term 14c variations may be an empirical indicator of holocene palaeoclimates and argue for possible origins of holocene climatic oscillations 1 the varying solar activity refers to secular climatic oscillations and to major climatic deteriorations showing a ca 2300 yr periodicity 2 a question is raised about a relationship between the earth s magnetic field and climate first the weak strength periods of the earth s dipole magnetic field between 3800 and ca 2500 b c coincide with higher climate variability and vice versa second the ca 2300 yr periods revealed by the 14c record and also by the major climatic deteriorations re corded in jurassian lakes ca 1500 a d ca 800 b c and ca 3500 b c coincide with the ca 2300 yr periods revealed by the earth s nondipole geomagnetic field the present warming induced by anthropogenic factors should be intensified during the next few centuries by natural factors of climate evolution

proxy climate record for the last 1000 years from irish blanket peat and a possible link to solar variability recent research has shown that ombrotrophic mires can yield a proxy climate signal based on changes in the degree of peat humification 1 2 and that oceanic margin sites show the most sensitive record 3 we compare humification records for the last 1000 yr from two radiocarbon dated blanket peat profiles from western ireland and show several corresponding periods of climatic fluctuations periods favouring reduced peat decomposition suggestive of wetter and or cooler climatic conditions seem to coincide with periods of reduced sunspot activity and atmospheric14c anomalies whilst climatologists have continued to debate a link between solar variability on a century timescale and climate change the exact nature of that link remains elusive 4 7 the results from ireland demonstrate that data derived from mires could be relevant to the debate as to the extent of solar forcing in natural climatic variability and the curves shown provide a continuous record to add to previous evidence for the so called medieval optimum and little ice age 8 the record may imply that during the past millennium climatic change at the oceanic margin of the northeast atlantic largely corresponded to inferred variations in solar output

multiproxy surface wetness records from replicate cores on an ombrotrophic mire implications for holocene palaeoclimate records ombrotrophic mires can provide records of palaeoclimate over the mid to late holocene in several areas of the world their potential is currently partly limited by difficulties with scaling indices based on plant macrofossils and humification and the need to account for the internal variability of the mire system this paper explores the use of testate amoebae analysis as a third technique and assesses the minimum within site variability by comparing results from two closely spaced cores reconstruction of surface wetness changes was carried out on cores from the centre of an intermediate raised blanket mire coom rigg moss northumberland by analysis of testate amoebae plant macrofossils and humification surface wetness changes were expressed as mean annual water table changes inferred from testate amoebae assemblages two separate indices based on plant macrofossils and percentage transmission of humification extracts comparisons between the proxies suggest good agreement of general trends in sphagnum peats but some differences in monocot and ericaceous peats the magnitude of surface wetness changes also differs within sphagnum peats the records from the separate cores converge over time and replicability between cores is best in the last 1000 yr changes over this period are similar to those shown by estimates based on documentary sources good agreement is obtained between a normalised plant macrofossil index and normalised reconstructed water table values and it is suggested that this approach could form the basis for improved composite multiproxy records from peatlands copyright 1999 john wiley sons ltd

a 7500 year peat based palaeoclimatic reconstruction and evidence for an 1100 year cyclicity in bog surface wetness from temple hill moss pentland hills southeast scotland analyses of plant macrofossils peat humification and testate amoebae were used to reconstruct a proxy climate record spanning the last 7500 years from an ombrotrophic bog temple hill moss in southeast scotland the plant macrofossil data were subjected to detrended correspondence analysis dca which modelled effectively the significant wet shifts within the record a mean water table depth transfer function was applied to the testate amoebae data to provide quantifiable changes the three proxy records show coherent phase changes which are interpreted as variability in past effective precipitation two tephra horizons glen garry and lairg a were used in conjunction with radiocarbon dates to construct an age depth model producing a robust geochronology from which a time series was calculated the palaeoclimatic reconstruction identified major wet shifts throughout the holocene with specific events occurring around cal 6650 5850 5300 4500 3850 3400 2800 2450 1450 1350 and 250 150 bp spectral analysis of the plant macrofossil dca and colorimetric humification data produced a millennial scale periodicity of 1100 years the same periodicity has also been found in a palaeoclimatic reconstruction from a site in cumbria walton moss and may be linked with millennial scale periodicities found in oceanic palaeoclimatic records

dating of recent lake sediments in the united kingdom and ireland using spheroidal carbonaceous particle scp concentration profiles spheroidal carbonaceous particles scps produced from fossil fuel combustion are found in lake sediments and provide a historical record of atmospheric pollutant deposition the sediment record of these particles is remarkably consistent and the main features are now seen throughout europe and beyond once the scp record from a region has been established using accurately dated cores scp profiles can be used to determine dates at other sites in the region this technique was developed in sweden brit until recently has had limited use in the uk and ireland as the most useful dating feature the subsurface peak was not present in all cores in recent cores this can now almost always be observed dating features for uk and irish cores are found to differ slightly between regions the potential exists for extra dates to be allocated to a profile by using characterisation of scp surfaces to determine changes in fuel type use dates could then be allocated to these changes using documentary sources to derive combustion histories in future years scp dating will become increasingly valuable especially for mid to late nineteenth century sediments as continual decay renders 210 pb progressively less useful for this time interval