crustal differentiation due to partial melting of granitic rocks in an active continental margin the ryoke belt southwest japan abstract the continental margin of pacific asia is dominated by the voluminous cretaceous to paleogene granitic rocks the ryoke granitoids that occur in the ryoke belt in the southwest japan arc are divided into the older and younger granites the high k kibe granite represents the younger granitic intrusion and is exposed in the yanai area in the western part of ryoke belt the kibe granite is associated with the coeval himurodake quartz diorite and their intrusive age is 91 ma however the gamano obatake granodiorite the older granite intruded the host ryoke gneisses at 95 ma the gamano obatake granodiorite is characterized by the localized development of migmatitic structure attributed to the intrusion of the himurodake quartz diorite into the granodiorite leucocratic pools and patches occur in the granodiorite in the vicinity of the quartz diorite the sr and nd isotopic compositions of the gamano obatake granodiorite corrected to 91 ma are plotted within those of the kibe granite geochemical modeling suggests that partial melting took place in the gamano obatake granodiorite and resulted in the formation of the kibe granite magma the himurodake quartz diorite is believed to be a heat source for this event this can be considered as an essential process for the formation of the evolved younger ryoke granite and for the crustal differentiation in the active continental margin

implications of subduction and subduction zone migration of the paleo pacific plate beneath eastern north china based on distribution geochronology and geochemistry of late mesozoic volcanic rocks several major volcanic zones are distributed across the eastern north china craton from northwest to southeast the greater xing an range jibei liaoxi xishan and songliao basins and the yanji huanghua and ludong volcanic zones the huanghua depression within the bohai bay basin was filled by middle late mesozoic volcanic rocks and abundant cenozoic alkaline basalts zircon la icp ms and shrimp u pb dating show that basic intermediate volcanic rocks were extruded in the early cretaceous of 118 8 1 0 ma weighted mean 206pb 238u age before late cretaceous acid lavas at 71 5 2 6 ma an inherited zircon from andesite has a paleoprotoerozoic core crystallization age of 2 424 22 ma 206pb 207pb age indicating that the basement of the bohai bay basin is part of the north china craton early cretaceous basic and intermediate lavas are characterized by strong enrichments in lree and lile and depletions in hree and hfse indicating a volcanic arc origin related to oceanic subduction depletion in zr only occurs in basic and intermediate volcanic rocks while depletions in sr and ti exist only in acid samples indicating that the acid series is not genetically related to the basic intermediate series formation ages and geochemical features indicate that the late cretaceous acid lavas are products of crustal remelting in an extensional regime combined information from all these volcanic zones shows that subduction related volcanic rocks were generated in the jibei liaoxi and xishan volcanic zones during the early jurassic about 60 ma earlier than their analogues extruded in the huanghua and ludong volcanic zones during the early cretaceous this younging trend also exists in the youngest extension related volcanism in each of these zones early cretaceous asthenosphere derived alkaline basalts in the northwest and late cretaceous in the southeast a tectonic model of northwestward subduction and continuous oceanward retreat of the paleo pacific plate is proposed to explain the migration pattern of both arc related and post subduction extension related volcanic rocks as the subduction zone continuously migrated active continental margin and backarc regimes successively played their roles in different parts of north china during the late mesozoic j1 k2

high spatial resolution electron probe microanalysis of tephras and melt inclusions without beam induced chemical modification wavelength dispersive analysis of tephra grains and melt inclusions by epma has been carried out using a focused beam of 3 m diameter without detected loss of sodium or potassium in standard glasses including anhydrous basalts a slightly hydrated rhyolite and a sodium rich intermediate composition the ability to make analyses without chemical modification is strongly dependent upon current density at the analysis site analysis with narrow beams requires extremely low beam currents that are normally associated with energy dispersive analysis experiments indicate that a value of 0 1 na m2 must not be exceeded at least for moderately hydrated samples if sodium loss is to be avoided high resolution analysis without beam induced analytical artefacts enables fully quantitative analysis of very distal and or highly vesicular tephras and very small melt inclusions without the need to use post analysis corrections this development has enabled high quality analyses from crypto tephra layers that were pre

plutonic rock types series discrimination of various granitoid series and related rocks abstract the streckeisen qap diagram discriminates four characteristic type series among the large variety of granitoids associated in intrusions three of them integrate varied compositions from basic to acid terms 1 the calcalkaline series with its low k or trondhiemite medium k or granodioritic high k or monzonitic variants 2 the alkaline series with its characteristic syenitic members 3 the tholeiitic series deprived of k feldspars the fourth 4 corresponds to mobilizates associated with migmatites of varied composition but always quartz rich the generalization in the qapf system allowing the plotting of undersaturated alkaline series provides an excellent visual display of the major associations and trends for the plutonic rocks

chironomids can be reliable proxies for holocene temperatures a comment on velle et al 2010 velle et al 2010 discussed discrepancies between scandinavian holocene chironomid inferred temperature estimates which they attribute to the response of chironomids to environmental variables other than temperature and to taxonomic shortcomings they suggest ways in which the reliability of chironomid based paleotemperature reconstructions could be improved by taking into account ecological complexity while we agree with many of their recommendations based on the results of other work we think their paper is unnecessarily pessimistic regarding the ability of existing chironomid based temperature inference models to provide reliable estimates of past temperature we offer a critique of the main points discussed by velle et al 2010 and provide evidence that chironomid based temperature inference models can reliably reconstruct mean july air temperature in the lateglacial and holocene over millennial and centennial timescales

biological responses to rapid climate change at the younger dryas holocene transition at krakenes western norway a fine resolution pollen stratigraphical study supported by macrofossil analysis has been made at krakenes lake western norway through the younger dryas holocene transition and the early holocen

rapid climate change during the weichselian lateglacial in ireland chironomid inferred summer temperatures from fiddaun co galway a lacustrine sediment core from fiddaun western ireland was studied to reconstruct summer temperature changes during the weichselian lateglacial this site is located close to the atlantic ocean and so is potentially sensitive to climatic changes associated with changes in ocean circulation the record comprising the end of the weichselian pleniglacial to the early holocene was analysed for fossil chironomids lithology and oxygen and carbon isotopes in the sedimentary carbonates these proxies clearly show rapid warming at the onset of the lateglacial interstadial relatively high summer temperatures during the interstadial pronounced cooling during the younger dryas and subsequent warming at the transition to the holocene chironomid inferred mean july air temperatures for the interstadial are 12 5 14 5 c 7 5 c for the younger dryas and 15 0 c for the early holocene furthermore this research provides evidence for at least two cold events during the interstadial these more moderate temperature oscillations can be correlated to greenland interstadial events 1b and 1d on the basis of the age depth model for the fiddaun sequence based on multiple proxies the first cold oscillation gi 1d was the more severe of the two in ireland

chironomid inferred late glacial summer air temperatures from lough nadourcan co donegal ireland western ireland located adjacent to the north atlantic and with a strongly oceanic climate is potentially sensitive to rapid and extreme climate change we present the first high resolution chironomid inferred mean july temperature reconstruction for ireland spanning the late glacial and early holocene lgit 15 10 ka bp the reconstruction suggests an initial rapid warming followed by a short cool phase early in the interstadial during the interstadial there are oscillations in the inferred temperatures which may relate to greenland interstadial events gi 1a e the temperature decrease into the stadial occurs in two stages this two stage drop can also be seen in other late glacial chironomid inferred temperature records from the british isles a stepped rise in temperatures into the holocene consistent with present day temperatures in donegal is inferred the results show strong similarities with previously published lgit chironomid inferred temperature reconstructions and with the ngrip oxygen isotope curve which indicates that the oscillations observed in the ngrip record are of hemispherical significance the results also highlight the influence of the north atlantic on the irish climate throughout the lgit copyright 2010 john wiley sons ltd

the impact of the north atlantic ocean on the younger dryas climate in northwestern and central europe the main results of multiproxy climate reconstructions for the younger dryas and experiments carried out with an atmospheric general circulation model are discussed quantitative temperature inferences for northwestern and central europe show that winter conditions were remarkably extreme with values of 20 30 c below that of today annual temperature ranges with a continental signature 30 34 c were reconstructed for the entire study area compared with today the greatest cooling was experienced in the seaboard area the comparison of the climate reconstructions and simulation experiments indicates that sea ice in the north atlantic ocean played a decisive role in the climate of the study area by cooling the surface air temperatures and by controlling the position of the storm track surface air circulation was westerly even during younger dryas winters a slight northward shift of the mean atlantic sea ice margin during winter may explain the proposed subdivision of the younger drays into a phase of maximum cold and humidity succeeded by a less cold and relatively dry phase 1998 john wiley sons ltd

high resolution lateglacial and early holocene summer air temperature records from scotland inferred from chironomid assemblages abstract lateglacial and early holocene mean july air temperatures have been reconstructed using a chironomid based inference model from lake sediment sequences from abernethy forest in the eastern highlands of scotland and loch ashik on the isle of skye in north west scotland chronology for abernethy forest was derived from radiocarbon dates of terrestrial plant macrofossils deposited in the lake sediments chronology for loch ashik was derived from tephra layers of known ages the first age depth model of this kind chironomid inferred temperatures peak early in the lateglacial interstadial and then gradually decline by about 1 c to the beginning of the younger dryas yd at abernethy forest the lateglacial interstadial is punctuated by three centennial scale cold oscillations which appear to be synchronous with the greenland interstadial events gi 1d when temperatures at abernethy fell by 5 9 c gi 1c when temperatures fell by 2 3 c and gi 1b when temperatures fell by 2 8 c at loch ashik only the oscillation correlated with gi 1d is clearly defined when temperatures fell by 3 8 c the start of the yd is clearly marked at both sites when temperatures fell by 5 5 c at abernethy forest and 2 8 c at loch ashik a warming trend is apparent during the late yd at abernethy forest but at loch ashik late yd temperatures became very cold possibly influenced by its close proximity to the skye ice field the rapidly rising temperatures at the yd holocene transition occur about 300 years earlier at both sites than changes in sediment lithology and loss on ignition the temperature trends at both sites are broadly similar although between site differences may result from the influence of local factors similar climate trends are found at other sites in the northern british isles however the british summer temperature records differ in detail from trends in the oxygen isotope records from the greenland ice cores and from other chironomid inferred temperature records available from scandinavia north west europe and central europe which suggest important differences in the influence of climatic forcing at regional scales

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

an adakitic pluton on kyushu island southwest japan arc abstract an adakitic pluton is designated the shiraishino granodiorite ca 15 km2 in outcrop area on kyushu island southwestern japanese arc sr y and rare earth element concentrations and crystallization characteristics of the pluton are similar to those of adakites geochemical and tectonic considerations show that the pluton was derived from partial melting of a subducted slab with minor contamination of high 87sr 86sr material and subsequent fractional crystallization of plagioclase hornblende compiled sr and y data indicate that most cretaceous granitic rocks of southwestern japan generated by partial melting of mafic lower crust adakitic plutons derived by slab melting occur rarely and have older ages it is concluded that plutonism in the southwestern japanese arc during cretaceous time was began with the emplacement of small adakitic intrusions and progressed to more abandant granitic rocks of the type derived from the mafic lower crust

chironomid inferred air temperatures from lateglacial and holocene sites in north west europe progress and problems abstract non biting midges insecta diptera chironomidae are now widely recognised as powerful biological proxies for inferring past climatic change in this paper the response of chironomid assemblages to lateglacial and holocene climatic change from sites in scotland and norway is discussed analyses have shown that midge assemblages have responded to major and minor climatic fluctuations during the last 15 000 yr such as the aegelsee oscillation gerzensee oscillation and younger dryas in the lateglacial and the thermal optimum little ice age and cooling events at 8 2 and 2 0 cal ka bp in the holocene in an attempt to quantify these and other climatic fluctuations a chironomid mean july air temperature inference model based on a modern calibration set of 109 lakes in norway and svalbard has been developed the 3 component weighted averaging partial least squares inference model performs well with a root mean squared error of prediction of 0 90 c and a maximum bias of 0 59 c both based on leave one out cross validation which is lower than chironomid temperature inference models developed in canada switzerland and finland however while temperature inference models perform well in the lateglacial the more subtle climatic changes of the holocene are more difficult to reconstruct because the likely temperature changes are close to the limits of the prediction errors of the existing models to address this problem future work is required to refine and develop the calibration set by further improving taxonomic resolution by adding more lakes to the calibration set and by investigating the influence of other environmental variables on chironomid distributions and abundances

chironomid inferred late glacial air temperatures at whitrig bog southeast scotland this paper presents the first chironomid inferred mean july air temperature reconstruction for the late glacial in britain the reconstruction suggests that the thermal maximum occurred early in the interstadial with temperatures reaching about 12 degreesc there was then a gradual downward trend to about 11 degreesc punctuated by four distinct cold oscillations of varying intensity at the beginning of the younger dryas mean july temperatures fell to about 7 5 degreesc but gradually increased to about 9 degreesc before a rapid rise at the onset of the holocene the chironomid inferred temperature curve agrees closely both in general trends and in detail with the grip ice core oxygen isotope curve the reconstructed temperatures are 2 4 degreesc lower than coleopteran inferred temperatures but are closer to those inferred from plant macrofossils and glacial equilibrium line altitudes during the younger dryas copyright c 2000 john wiley sons ltd

high pmetamorphism pattern of induced flow in the mantle wedge and the link with plutonism in paired metamorphic belts the convex form of subduction stage pressure temperature p t paths up to c 2 0 gpa implies the sambagawa high p metamorphic belt japan formed a few million years before ridge subduction additional compilation of p t conditions for higher p sambagawa rocks c 2 0 2 5 gpa reveals that the thermal profile along the slab surface shows a remarkable high t ward warping at c 2 0 gpa c 65 km previous thermal models indicate that this warping corresponds to the onset of induced mantle flow towards the subducting slab if a normal thickness continental crust of c 30 km was present this implies the hangingwall region between 30 and 65 km depth was occupied by serpentinized wedge mantle isolated from large scale mantle flow subsequent arrival of the spreading ridge reheating and dehydration of the serpentinized wedge probably supplied the water necessary for causing granitic magmatism in the ryoke high t metamorphic belt which is paired with the sambagawa belt

dehydration melting and water saturated melting of basaltic and andesitic greenstones and amphibolites at 1 3 and 6 9 kb

improved age estimates for key late quaternary european tephra horizons in the reset lattice abstract the research project response of humans to abrupt environmental transitions reset used tephra layers to tie together and synchronise the chronologies of stratigraphic records at archaeological and environmental sites with the increasing importance of tephra as chronological markers in sedimentary sequences both in this project and more generally comes a requirement to have good estimates for the absolute age of these volcanic horizons this paper summarises the chronology of the key tephra in the reset tephra lattice in the time range 10 60 ka bp from the existing literature from papers produced as part of the reset project and reanalysis conducted for this paper the paper outlines the chronological approach taken to the dating of tephra within the reset project and the basis for further work as part of the intimate integrating ice core marine and terrestrial records initiative for each of the tephra layers in the lattice the existing literature is discussed and where relevant date estimates updated using the latest radiocarbon calibration curves intcal13 and marine13 and methods maps show the approximate extent of tephra finds giving a visual indication of the coverage of the lattice in different time periods

delayed deglaciation or extreme arctic conditions 21 16 cal kyr at southeastern laurentide ice sheet margin 1 the conventionally accepted ages of the last glacial maximum lgm retreat of the southeastern laurentide ice sheet lis are 26 21 cal kyr derived from bulk sediment radiocarbon ages and 28 23 cal kyr varve estimates utilizing accelerator mass spectrometry ams 14c dating of earliest macrofossils in 13 lake bog inorganic clays we find that vegetation first appeared on the landscape at 16 15 cal kyr suggesting ice had not retreated until that time the gap between previous age estimates and ours is significant and has large implications for our understanding of ocean atmosphere linkages older ages imply extreme arctic conditions for 9 5 cal kyr a landscape with no ice yet no deposition in lakes our new ams chronology of lis retreat is consistent with marine evidence of deglaciation from the n atlantic showing significant freshwater input and sea level rise only after 19 cal kyr with a cold meltwater lid perhaps delaying ice melt

interhemispheric atlantic seesaw response during the last deglaciation the asynchronous relationship between millennial scale temperature changes over greenland and antarctica during the last glacial period has led to the notion of a bipolar seesaw which acts to redistribute heat depending on the state of meridional overturning circulation within the atlantic ocean here we present new records from the south atlantic that show rapid changes during the last deglaciation that were instantaneous within dating uncertainty and of opposite sign to those observed in the north atlantic our results demonstrate a direct link between the abrupt changes associated with variations in the atlantic meridional overturning circulation and the more gradual adjustments characteristic of the southern ocean these results emphasize the importance of the southern ocean for the development and transmission of millennial scale climate variability and highlight its role in deglacial climate change and the associated rise in atmospheric carbon dioxide

rapid oceanic and atmospheric changes during the younger dryas cold period the younger dryas event which began approximately 12 900 years ago was a period of rapid cooling in the northern hemisphere driven by large scale reorganizations of patterns of atmospheric and oceanic circulation 1 3 environmental changes during this period have been documented by both proxy based reconstructions 3 and model simulations 4 but there is currently no consensus on the exact mechanisms of onset stabilization or termination of the younger dryas 5 8 here we present high resolution records from two sediment cores obtained from lake krakenes in western norway and the nordic seas multiple proxies from lake krakenes are indicative of rapid alternations between glacial growth and melting during the later younger dryas meanwhile reconstructed sea surface temperature and salinity from the nordic seas show an alternation between sea ice cover and the influx of warm salty north atlantic waters we suggest that the influx of warm water enabled the westerly wind systems to drift northward closer to their present day positions the winds thus brought relatively warm maritime air to northern europe resulting in rising temperatures and the melting of glaciers subsequent input of this fresh meltwater into the ocean spurred the formation of sea ice which forced the westerly winds back to the south cooling northern europe we conclude that rapid alternations between these two states immediately preceded the termination of the younger dryas and the permanent transition to an interglacial state the impact of freshwater pulses released from northern hemisphere ice sheets on the north atlantic meridional overturning circulation has been suggested as a likely mechanism for the younger dryas cooling 7 11 in addition a responsive sea ice cover has been proposed as a mechanism that could rapidly alter the heat exchange between the ocean and atmosphere during the last glacial period 12 13 the roles of the ocean and the atmosphere in triggering the climate shifts around the younger dryas are much discussed 9 these hypotheses are difficult to resolve partly because the temporal resolution of most palaeoclimate archives is too coarse to enable the anatomy of the younger dryas stadial to be adequately described 14 to address these questions we here present a lake sediment record at sub annual resolution together with new data on the sea surface conditions of the norwegian atlantic current nwac throughouttheyoungerdryasstadial fig 1

evidence for significant clockwise rotations of the korean peninsula during cretaceous abstract in an effort to evaluate the cretaceous magnetostratigraphy for the korean peninsula and to establish the tectonic coherence of its various elements we collected paleomagnetic data from 121 samples from 20 sites within the chilgok formation 108 3 109 9 ma in the gyeongsang basin together with previously published data we evaluate the results from a total of 163 sites in the basin we combine our age model with results from recent stratigraphic paleomagnetic and radiometric geochemical studies in this study we found that two distinct declination shifts decrease with younging direction indicating two clockwise rotational events of the korean peninsula with respect to the eurasia continent the earlier event took place during 130 100 ma phase i newly termed goguryeo disturbance and a later one during 80 50 ma phase iii belonging to bulguksa orogeny the mean rotation rate in the interval from 115 2 to 103 8 ma phase i is about 0 74 ma while the rate from 90 9 to 79 8 ma phase ii is 0 19 ma based on paleolatitude change during phase i we infer that the korean peninsula eastern part of the sino korea block migrated southward about 300 km after the complete amalgamation of the sino korea block into the eurasian continent resulting in n s compression within the korean peninsula and manchuria large scale strike slip faults e g tan lu fault okcheon boundary fault were probably rejuvenated in the sino korea block during phase i

a multiproxy micro xrf pollen chironomid and stable isotope lake sediment record for the lateglacial to holocene transition from thomastown bog ireland a multiproxy lateglacial environmental record is presented for a ca 3 5 m lacustrine sequence retrieved from a small basin ca 2 km2 at thomastown bog in county meath ireland sediment chemistry pollen chironomid and stable isotope data provide a detailed picture of catchment and lake system changes from the end of the last glacial gs 2a to the early holocene that correspond closely to existing local and regional models of climate change concomitant adjustments in independent proxy records are matched to the ngrip oxygen isotope curve giving 12 event episodes ranging from major climatic shifts to lower amplitude centennial to sub centennial scale adjustments including a previously unreported regressive period of landscape instability during the north west european rammelbeek phase the study emphasizes the potential of palaeoenvironmental reconstruction from sediment chemistry where the sediment mixing system reflects autochthonous versus allochthonous inputs the investigation also indicates problems of interpreting isotope data derived from bulk marl due to possible lag effects controlling the delivery of soil and groundwater and multiple sources of hco3 aq these research findings have implications for core site selection and for studies attempting to use stable isotopes for correlation purposes

topographic controls on plateau icefield recession insights from the younger dryas monadhliath icefield scotland plateau icefields are a common form of mountain ice mass frequently found in mid latitude to high arctic regions and increasingly recognized in the quaternary record their top heavy hypsometry makes them highly sensitive to changes in climate when the equilibriaum line altitude ela lies above the plateau edge allowing ice to expand significantly as regional elas decrease and causing rapid recession as climate warms with respect to future climate warming it is important to understand the controls on plateau icefield response to climate change in order to better predict recession rates with implications for water resources and sea level rise improving knowledge of the controls on glacier recession may also enable further palaeoclimatic information to be extracted from the quaternary glacial record we use the distribution of moraines to examine topographic controls on younger dryas icefield recession in scotland we find that overall valley morphology influences the style of recession through microclimatic and geometric controls with bed gradient affecting moraine spacing ice mass reconfiguration may occur as recession progresses because ice divide migration could alter the expected response based on hypsometric distribution these results add to a growing body of research examining controls on glacier recession and offer a step towards unravelling non linear ice mass behaviour less

tephrochronology and the extended intimate integration of ice core marine and terrestrial records event stratigraphy 8 128 ka b2k the comparison of palaeoclimate records on their own independent timescales is central to the work of the intimate integrating ice core marine and terrestrial records network for the north atlantic region an event stratigraphy has been established from the high precision greenland ice core records and the integrated gicc05 chronology this stratotype provides a palaeoclimate signal to which the timing and nature of palaeoenvironmental change recorded in marine and terrestrial archives can be compared to facilitate this wider comparison without assuming synchroneity of climatic change proxy response intimate has also focussed on the development of tools to achieve this in particular the use of time parallel marker horizons e g tephra layers volcanic ash coupled with the recent temporal extension of the greenland stratotype as part of this special issue we present an updated intimate event stratigraphy highlighting key tephra horizons used for correlation across europe and the north atlantic we discuss the advantages of such an approach and the key challenges for the further integration of terrestrial palaeoenvironmental records with those from ice cores and the marine realm

dating synthesis and interpretation of palaeoclimatic records of the last glacial cycle and model data integration advances by the intimate integration of ice core marine and terrestrial records cost action es0907 since 2010 the intimate integration of ice core marine and terrestrial records network has been operating as a cost action designated es0907 this paper outlines the accomplishments of the intimate cost action in the context of how the intimate ideas have evolved during the network s twenty year life span and highlights a number of challenges that can guide further work in the second part of the paper the contributions that comprise this intimate special issue are introduced

precise 14c ages of the vedde and saksunarvatn ashes and the younger dryas boundaries from western norway and their comparison with the greenland ice core gicc05 chronology the greenland ice cores with the gicc05 chronology represent a standard for late quaternary climate events and their ages whereas many other palaeoclimatic archives are dependent on 14 c dates it is therefore critical to know if the ice core and the calibrated 14 c chronologies are identical and if not to quantify the offset between them we present bayesian age depth modelling of 118 accelerator mass spectrometry 14 c dates from kraukenes lake calibrated using intcal09 that provide high precision ages of 12 066 42 and 10 210 35 cal a bp for the vedde and saksunarvatn ashes respectively the lower and upper younger dryas boundaries have ages of 12 710 52 and 11 546 59 cal a bp respectively the four dated levels coincide with correlative levels in gicc05 within the dating uncertainties but are all consistently younger at kraukenes the ages of the tephra chronostratigraphic markers suggest a mean offset of 70 years to older ages in the gicc05 compared with the intcal09 time scale responses to small climate changes 30 years before the younger dryas boundaries at kraukenes are suggested to correspond to the defined greenland stadial 1 boundaries this suggested difference in timing 30 years and time scale offset 70 years mean that the greenland stadial 1 boundaries appear 100 years older than the younger dryas boundaries copyright 2013 john wiley sons ltd

new age estimates and climatostratigraphic correlations for the borrobol and penifiler tephras evidence from abernethy forest scotland the emerging tephrostratigraphy of nw europe spanning the last termination ca 15 9 ka provides the potential for synchronizing marine ice core and terrestrial records but is currently compromised by stratigraphic complications geochemical ambiguity and imprecise age estimates for some layers here we present new tephrostratigraphic radiocarbon and chironomid based palaeotemperature data from abernethy forest scotland that refine the ages and stratigraphic positions of the borrobol and penifiler tephras the borrobol tephra 14 14 13 95 cal ka bp was deposited in a relatively warm period equated with greenland interstadial sub stage gi 1e the younger penifiler tephra 14 09 13 65 cal ka bp is closely associated with a cold oscillation equated with gi 1d we also present evidence for a previously undescribed tephra layer that has a major element chemical signature identical to the vedde ash it is associated with the warming trend at the end of the younger dryas and dates between 11 79 and 11 20 cal ka bp copyright 2011 john wiley sons ltd

influence of interaction between small asperities on various types of slow earthquakes in a 3 d simulation for a subduction plate boundary recently the occurrence of slow earthquakes such as low frequency earthquakes and very low frequency earthquakes have been recognized at depths of about 30 km in southwest japan and cascadia these slow earthquakes occur sometimes in isolation and sometimes break into chain reaction producing tremor that migrates at a speed of about 5 15 km day and suggesting a strong interaction among nearby small asperities in this study we formulate a 3 d subduction plate boundary model with two types of small asperities chained along the trench at the depth of 30 km our simulation succeeds in representing various types of slow earthquakes including low frequency earthquakes and rapid slip velocity in the same asperity and indicates that interaction between asperities may cause the very low frequency earthquakes our simulation also shows chain reaction along trench with propagation speed that can be made consistent with observations by adjusting model parameters which suggests that the interactions also explain the observed migration of slow earthquakes

the reset tephra database and associated analytical tools abstract an open access database has been set up to support the research project studying the response of humans to abrupt environmental transitions reset the main methodology underlying this project was to use tephra layers to tie together and synchronise the chronologies of stratigraphic records at archaeological and environmental sites the database has information on occurrences and chemical compositions of glass shards from tephra and cryptotephra deposits found across europe the data includes both information from the reset project itself and from the published literature with over 12 000 major element analyses and over 3000 trace element analyses on glass shards relevant to 80 late quaternary eruptions the reset project has generated an important archive of data when added to the published information the database described here has a total of more than 22 000 major element analyses and nearly 4000 trace element analyses on glass from over 240 eruptions in addition to the database and its associated data new methods of data analysis for assessing correlations have been developed as part of the project in particular an approach using multi dimensional kernel density estimates to evaluate the likelihood of tephra compositions matching is described here and tested on data generated as part of the reset project

the last glacial termination a major puzzle of paleoclimatology is why after a long interval of cooling climate each late quaternary ice age ended with a relatively short warming leg called a termination we here offer a comprehensive hypothesis of how earth emerged from the last global ice age a prerequisite was the growth of very large northern hemisphere ice sheets whose subsequent collapse created stadial conditions that disrupted global patterns of ocean and atmospheric circulation the southern hemisphere westerlies shifted poleward during each northern stadial producing pulses of ocean upwelling and warming that together accounted for much of the termination in the southern ocean and antarctica rising atmospheric co2 during southern upwelling pulses augmented warming during the last termination in both polar hemispheres

age and evolution of a late archean to paleoproterozoic upper to lower crustal section in the wutaishan hengshan fuping terrain of northern china abstract the taihangshan wutaishan area forms part of the central north china craton and consists of three main components the hengshan and fuping complexes containing predominantly ductilely deformed late archean to paleoproterozoic high grade granitoid orthogneisses intruded by mafic dykes of gabbroic composition and the low grade late archean wutai greenstone belt developed between the high grade terrains and consisting of bimodal volcanic rocks and metasediments associated with coeval granitoids zircon dating shows that both the hengshan and fuping complexes were intruded by major granitoid bodies between 2 52 and 2 48 ga with rare occurrences of 2 7 ga gneisses wutai granitoids adjacent to the fuping complex also contain 2 7 ga xenocrysts all possibly reflecting the same older basement rare granitic gneisses in the hengshan have emplacement ages of 2 35 ga and show the same structural features as the older rocks indicating that the main deformation occurred after 2 3 ga deposition of supracrustal rocks and emplacement of mafic dykes occurred in the paleoproterozoic together with intrusion of granitic bodies at 2 1 2 0 ga and all underwent regional metamorphism at 1 88 1 85 ga we interpret the hengshan and fuping granitoid gneisses as the lower plutonic part of a late archean to early paleoproterozoic japan type magmatic arc with the upper volcanic part represented by the wutai complex components of this arc may have evolved at a continental margin as indicated by the 2 7 ga zircons virtually all magmatic events are recorded in all three complexes however the 1 85 ga metamorphic event is only recorded in the higher grade portions of the wutai since low grade and presumably high crustal level precluded metamorphic zircon growth shear zones in the hengshan are interpreted as major lower crustal discontinuities post dating the peak of high pressure granulite metamorphism we suggest that they formed during orogenic collapse and uplift of the hengshan complex in the late paleoproterozoic 1800 ma

late orogenic post orogenic and anorogenic granites distinction by major element and trace element chemistry and possible origins granites classified into four categories based solely on tectonics of occurrence and associated rock types also have compositional characteristics that are consistent within groups and different am

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

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

an initial continental margin plutonism cretaceous older ryoke granitoids southwest japan the emplacement of the older ryoke granitoids took place in the mid cretaceous period in the outermost side of the inner zone of southwest japan which was located at the eastern margin of the eurasian continent before the opening of the japan sea the ryoke belt constitutes a long segment of the cretaceous to palaeogene felsic magmatic belt of pacific asia the older ryoke granitoids represent its initial magmatism related to the subduction of an oceanic plate underneath the eurasian plate in that time their magmas were generated in the lower to middle crust beneath the ryoke belt in the subduction regime they were emplaced during the ryoke regional metamorphism and converted to orthogneisses

synchronisation of palaeoenvironmental events in the north atlantic region during the last termination a revised protocol recommended by the intimate group abstract the north atlantic intimate group of the inqua palaeoclimate commission has previously recommended an event stratigraphy approach for the synchronisation of records of the last termination using the greenland grip isotopic record as the regional stratotype and intcal98 for the calibration of radiocarbon dates lowe j j hoek w intimate group 2001 inter regional correlation of palaeoclimatic records for the last glacial interglacial transition a protocol for improved precision recommended by the intimate project group quaternary science reviews 20 1175 1187 here we present a revised protocol for time stratigraphic correlation in the north atlantic region over a more extended time period 30 8 ka this employs the new ngrip isotopic record and associated greenland ice core chronology 2005 gicc05 as the regional stratotype intcal04 for the calibration of radiocarbon dates bayesian based statistical procedures for the construction of age models and tephrochronology to validate correlations between regional site records

a stratigraphic framework for abrupt climatic changes during the last glacial period based on three synchronized greenland ice core records refining and extending the intimate event stratigraphy due to their outstanding resolution and well constrained chronologies greenland ice core records provide a master record of past climatic changes throughout the last interglacial glacial cycle in the north atlantic region as part of the intimate integration of ice core marine and terrestrial records project protocols have been proposed to ensure consistent and robust correlation between different records of past climate a key element of these protocols has been the formal definition and ordinal numbering of the sequence of greenland stadials gs and greenland interstadials gi within the most recent glacial period the gs and gi periods are the greenland expressions of the characteristic dansgaard oeschger events that represent cold and warm phases of the north atlantic region respectively we present here a more detailed and extended gs gi template for the whole of the last glacial period it is based on a synchronization of the ngrip grip and gisp2 ice core records that allows the parallel analysis of all three records on a common time scale the boundaries of the gs and gi periods are defined based on a combination of stable oxygen isotope ratios of the ice 18o reflecting mainly local temperature and calcium ion concentrations reflecting mainly atmospheric dust loading measured in the ice the data not only resolve the well known sequence of dansgaard oeschger events that were first defined and numbered in the ice core records more than two decades ago but also better resolve a number of short lived climatic oscillations some defined here for the first time using this revised scheme we propose a consistent approach for discriminating and naming all the significant abrupt climatic events of the last glacial period that are represented in the greenland ice records the final product constitutes an extended and better resolved greenland stratotype sequence against which other proxy records can be compared and correlated it also provides a more secure basis for investigating the dynamics and fundamental causes of these climatic perturbations

regional consistency in lateglacial chironomid inferred temperatures from five sites in north west england abstract high resolution lateglacial ice core records from greenland show both millennial and centennial scale change and have been used as a benchmark for lateglacial climatic stratigraphy throughout the north atlantic region and beyond in this study we assess the local reflection in north west europe of climatic events recognised in ice cores and identify differences in the climate signature between greenland uk and sites in continental europe this study uses chironomid inferred temperature analysis and loss on ignition data from five carbonate lakes in north west england to determine the pattern of lateglacial climatic change and demonstrates the reproducibility of chironomid inferred temperature reconstructions both within a catchment and from sites within a small area at both millennial and centennial scales our results show statistical similarities between sites giving a clear regional signal chironomid assemblages pick out the rapid shifts at the major event boundaries at all sites and indicate temperatures of between 12 and 13 c for the region at the beginning of greenland interstadial 1 a rapid fall of around 4 c into the younger dryas and a rise of around 5 c in the early holocene at a finer scale four centennial cooling events are identified within the interstadial together with an oscillation in the early holocene which we tentatively identify as the pre boreal event the records were analysed statistically using redundancy analysis and sequence slotting techniques differences in the impact of individual climatic events demonstrate that subtle changes in the chironomid inferred temperatures reflect the local geographical setting and morphology of the lakes with more marked impact registered in higher altitude and more wind exposed sites whilst the overall pattern of lateglacial climate can be recognised from greenland to central europe important regional differences that can be attributed to marine influence and perhaps changes in atmospheric circulation are beginning to emerge

a new and less destructive laboratory procedure for the physical separation of distal glass tephra shards from sediments abstract tephrochronology a key tool in the correlation of quaternary sequences relies on the extraction of tephra shards from sediments for visual identification and high precision geochemical comparison a prerequisite for the reliable correlation of tephra layers is that the geochemical composition of glass shards remains unaltered by natural processes e g chemical exchange in the sedimentary environment and or by laboratory analytical procedures however natural glasses particularly when in the form of small shards with a high surface to volume ratio are prone to chemical alteration in both acidic and basic environments current techniques for the extraction of distal tephra from sediments involve the cleaning of samples in precisely such environments and at elevated temperatures the acid phase of the cleaning process risks alteration of the geochemical signature of the shards while the basic phase leads to considerable sample loss through dissolution of the silica network here we illustrate the degree of alteration and loss to which distal tephras may be prone and introduce a less destructive procedure for their extraction this method is based on stepped heavy liquid flotation and which results in samples of sufficient quality for analysis while preserving their geochemical integrity in trials this method out performed chemical extraction procedures in terms of the number of shards recovered and has resulted in the detection of new tephra layers with low shard concentrations the implications of this study are highly significant because i the current database of distal tephra records and their corresponding geochemical signatures may require refinement and ii the record of distal tephras may be incomplete due to sample loss induced by corrosive laboratory procedures it is therefore vital that less corrosive laboratory procedures are developed to make the detection and classification of distal glass tephra more secure

volcanic ash reveals time transgressive abrupt climate change during the younger dryas knowledge of regional variations in response to abrupt climatic transitions is essential to understanding the climate system and anticipating future changes global climate models typically assume that major climatic changes occur synchronously over continental to hemispheric distances the last major reorganization of the ocean atmosphere system in the north atlantic realm took place during the younger dryas yd an 1100 yr cold period at the end of the last glaciation within this region several terrestrial records of the yd show at least two phases an initial cold phase followed by a second phase of climatic amelioration related to a resumption of north atlantic overturning we show that the onset of climatic amelioration during the yd cold period was locally abrupt but time transgressive across europe atmospheric proxy signals record the resumption of thermohaline circulation midway through the younger dryas occurring 100 yr before deposition of ash from the icelandic vedde eruption in a german varve lake record and 20 yr after the same isochron in western norway 1350 km farther north synchronization of two high resolution continental records using the vedde ash layer 12 140 40 varve yr b p allows us to trace the shifting of the polar front as a major control of regional climate amelioration during the yd in the north atlantic realm it is critical that future climate models are able to resolve such small spatial and chronological differences in order to properly encapsulate complex regional responses to global climate change

acid dissolution of antigorite chrysotile and lizardite for ex situ carbon capture and storage by mineralisation serpentine minerals serve as a mg donor in carbon capture and storage by mineralisation ccsm the acid treatment of nine comprehensively examined serpentine polymorphs and polytypes and the subsequent microanalysis of their post test residues highlighted several aspects of great importance to the choice of the optimal feed material for ccsm compelling evidence for the non uniformity of serpentine mineral performance was revealed and the following order of increasing mg extraction efficiency after three hours of acid leaching was established al bearing polygonal serpentine 5 al bearing lizardite 1t 5 antigorite 24 29 well ordered lizardite 2h1 65 al poor lizardite 1t 68 chrysotile 70 poorly ordered lizardite 2h1 80 nanotubular chrysotile 85 it was recognised that the mg extraction efficiency of the minerals depended greatly on the intrinsic properties of crystal structure chemistry and rock microtexture on this basis antigorite and al bearing well ordered lizardite were rejected as potential feedstock material whereas any chrysotile non aluminous widely spaced lizardite and or disordered serpentine were recommended the formation of peripheral siliceous layers tens of microns thick was not universal and depended greatly upon the intrinsic microtexture of the leached particles this study provides the first comprehensive investigation of nine carefully selected serpentine minerals covering most varieties and polytypes under the same experimental conditions we focused on material characterisation and the identification of the intrinsic properties of the minerals that affect particle s reactivity it can therefore serve as a generic basis for any acid based ccsm pre treatment

geochemical characteristics and variations of the ryoke granitoids southwest japan petrogenetic implications for the plutonic rocks of a magmatic arc abstract geochemical characteristics and variations of the ryoke granitoids southwest japan have been elucidated based on more than 70 analyses from the mikawa and kinki districts for major and trace elements including ree the ryoke granitoids are the products of a continental margin arc magmatism of pacific asia during late cretaceous period and represent its magmatic front they are classified into the older and younger groups according to their intrusive ages and textural and petrographic characteristics the older ryoke granitoids were emplaced at ca 20 km depth during 100 85 ma and deformed and recrystallized together with the host ryoke metamorphic rocks the younger ryoke granitoids are post tectonic plutons emplaced at ca 15 km depth 85 75 ma and accompanied by the formation of contact aureoles the majority belongs to i type and ilmenite series granitoids the granitoids of both groups are geochemically quite similar calcic alkali lime index 65 very low in fe 3 fe 2 ratio and both metaluminous and peraluminous they have low rb