evolution of a tertiary volcanogenic trough in sw turkey the alakaya basins of the lycien belt field study of several stratigraphic sections from allochthonous thrust fault slices of sw turkey reveal that a deeply subsiding volcanogenic trough the alakaya basin existed during paleocene middle eocene times along the lycian belt the alakaya basin was located along a tectonically active zone of weakness between two relatively stable tectonic terrains the menderes massif to the northwest and the beydaglari continental platform to the southeast the basin was underlain by continental substratum all known outcrops of the alakaya sediments overlie platform carbonates of cretaceous age that correlate with the beydaglari shelf sediments the generation of the volcanogenic alakaya basin reflects a tensional period that culminated in middle eocene when basic volcanic activity took place the tensional stage was replaced by a compressional regime in late eocene and large scale overthrust faulting took place the alakaya basin was closed when the tefenni nappe from the north was emplaced on its sediments in late eocene the alakaya sediments overlying the tefenni nappe and underlying the cretaceous platform carbonates moved southeastward over a hundred kilometers onto the autochthonous sediments of the beydaglari terrain in miocene time the alakaya basin is analogous to the maden basin of se turkey thrust fault belt both basins were located along tectonically active belts the main stage of basin subsidence and volcanism was in middle eocene closure of both basins by large scale thrust faulting was in late eocene the creation and destruction of the volcanogenic alakaya basin may be related to the regional adjustments in plate motions in paleocene eocene times

bibliography on infrasonic waves the following bibliography is current through 1970 and is composed of references related to the generation propagation and detection of sound radiation at ground level and ionospheric heigbts the frequency range of the pressure signals considered here encompasses those normally associated with acoustic infrasonic acousticgravity and gravity waves as an aid in locating references the material has been broken into a number of subject categories which are given below each entry is listed only under the subject that is considered to be the primary topic of the paper

mutvei s solution an ideal agent for resolving microgrowth structures of biogenic carbonates accretionary hard parts of many organisms provide excellent archives of past climate and environmental conditions or life history traits variable growth rates function as environmental and physiological proxies and growth increments as calendars recognition of growth structures is thus a prime necessity for sclerochronological studies here we present a new handy easy to use and time efficient technique that resolves annual and sub annual growth structures in skeletons of a wide range of different organisms mutvei s solution simultaneously etches biogenic carbonates and calcium phosphates fixates the soluble and insoluble organic matrices and fibers and stains mucopolysaccharides it produces a filigreed three dimensional relief of etch resistant ridges growth lines and etched depressions growth increments and stains skeletal growth structures in shadings of blue growth lines stand out as crisp darker blue stained lines reflected optical light microscopy axial and oblique illumination and scanning electron microscopy can be used to analyze the microgrowth structures we demonstrate the use of the technique on hard tissues of various marine and freshwater bivalves a coral a sclerosponge a barnacle gastropods a cephalopod a fish otolith and a whale s ear bone this technique may be of interest for paleoclimatologists geochemists and biologists it can significantly expand the use of biogenic hard parts as environmental and physiological indicators because it reveals microgrowth structures of biogenic skeletons that potentially form on a periodic basis and thus function as calendars

tropical sea surface temperatures for the past four centuries reconstructed from coral archives most annually resolved climate reconstructions of the common era are based on terrestrial data making it a challenge to independently assess how recent climate changes have affected the oceans here as part of the past global changes ocean2k project we present four regionally calibrated and validated reconstructions of sea surface temperatures in the tropics based on 57 published and publicly archived marine paleoclimate data sets derived exclusively from tropical coral archives validation exercises suggest that our reconstructions are interpretable for much of the past 400 years depending on the availability of paleoclimate data within and the reconstruction validation statistics for each target region analysis of the trends in the data suggests that the indian western pacific and western atlantic ocean regions were cooling until modern warming began around the 1830s the early 1800s were an exceptionally cool period in the indo pacific region likely due to multiple large tropical volcanic eruptions occurring in the early nineteenth century decadal scale variability is a quasi persistent feature of all basins twentieth century warming associated with greenhouse gas emissions is apparent in the indian west pacific and western atlantic oceans but we find no evidence that either natural or anthropogenic forcings have altered el nino southern oscillation related variance in tropical sea surface temperatures our marine based regional paleoclimate reconstructions serve as benchmarks against which terrestrial reconstructions as well as climate model simulations can be compared and as a basis for studying the processes by which the tropical oceans mediate climate variability and change

stratigraphy and geochemistry of pillow basalts within the ophiolitic melange of the izmir ankara erzincan suture zone implications for the geotectonic character of the northern branch of neotethys the izmir ankara erzincan suture zone of turkey is a broad zone of ophiolitic melange containing numerous fragmented blocks ranging in age from triassic to cretaceous stratigraphic sequences for various melange units are compared together with the geochemistry of associated basaltic pillow lavas of cretaceous age a review of geochemical data for the pillow lavas demonstrate a a dominant group of alkalic basalts with enriched incompatible elements variable zr y and zr nb ratios and b a range of tholeiitic basalts with slightly depleted to mildly enriched normalized rare earth patterns la yb n 0 4 3 0 and generally low zr y ratios the alkalic basalts can be chemically matched to pacific ocean seamounts although the close association of red radiolarites and cherts suggests that many basalts represent the margins of such structures rather than the main seamount edifice nd sr isotope data are typical for ocean island basalts and represent an admixture of a dominant em 1 source and a depleted morb like source enhanced 18o compositions are a consequence of submarine alteration and not crustal contamination tholeiitic compositions have affinities with both n and e type morb although most are probably representative of tholeiitic ocean islands overall the basalts are mainly representative of structures built on the ocean floor rather than the oceanic crust itself being scraped off the subducting crust and preserved in the melange of the accretionary wedge

determination of sea surface temperatures using oxygen isotope ratios from phorcus lineatus da costa 1778 in northern spain implications for paleoclimate and archaeological studies changes in oxygen isotope ratios from shell carbonates are mainly dependent on sea surface temperature which enables the estimation of temperatures during periods of shell growth and helps to dete

advancements in the use of speleothems as climate archives abstract speleothems have become a cornerstone of the approach to better understanding earth s climatic teleconnections due to their precise absolute chronologies their continuous or semicontinuous deposition and their global terrestrial distribution we review the last decade of speleothem related research building off a similar review by mcdermott 2004 in three themes i investigation of global teleconnections using speleothem based climate reconstructions ii refinement of climate interpretations from speleothem proxies through cave monitoring and iii novel technical methods of speleothem based climate reconstructions speleothem records have enabled critical insight into the response of global hydroclimate to large climate changes this includes the relevant forcings and sequence of climatic responses involved in glacial terminations and recognition of a global monsoon response to climate changes on orbital and millennial time scales we review advancements in understanding of the processes that control speleothem 13 c values and introduce the idea of a direct atmospheric pco 2 influence we discuss progress in understanding kinetic isotope fractionation which with further advances may help quantify paleoclimate changes despite non equilibrium formation of speleothems this feeds into the potential of proxy system modeling to consider climatic hydrological and biogeochemical processes with the objective of quantitatively interpreting speleothem proxies finally we provide an overview of emerging speleothem proxies and novel approaches using existing proxies most recently technical advancements made in the measurement of fluid inclusions are now yielding reliable determinations of paleotemperatures

precise temporal correlation of holocene mollusk shells using sclerochronology abstract annual growth bands of mollusk shells record several types of paleoenvironmental information including geochemical proxies for water properties and morphological characteristics of growth and mortality sclerochronology the marine counterpart of dendrochronology offers a way to link individual shells together to form long continuous records of such parameters it also allows for precise dating of recent shells and identification of contemporaneous fossil individuals the longevity of the ocean quahog arctica islandica commonly 100 yr makes this species well suited for sclerochronology band width records of contemporaneous a islandica specimens from the same region exhibit high correlations 0 60 0 80 for spans of 30 bands indicating some common environmental influences on shell growth by adopting several strict criteria fossil dead collected shells can be linked into composite sclerochronologies a seven shell 154 yr chronology was constructed for georges bank using three live collected and four dead collected shells band width matching indicates that the dead collected individuals died in a d 1950 1971 1978 and 1989 sclerochronological age assignments were verified using aspartic acid racemization dating construction of a 1000 yr sclerochronology is judged to be feasible using the described methods

food for thought mathematical approaches for the conversion of high resolution sclerochronological oxygen isotope records into sub annually resolved time series abstract oxygen isotope 18 o records of incrementally banded marine calcifiers provide high resolution information about modern and past environmental conditions however given their biological origin these records are often distorted by ontogenetic and seasonal growth pattern to evaluate their reliability many studies correlate skeletal 18 o records with instrumentally measured time series of environmental conditions using a variety of methods to recalculate their temporal framework lacking consistency and a limited traceability of many temporal alignment methods underline the need for standardized and flexible method for the temporal alignment of sclerochronological records here two methods for the temporal alignment of sclerochronological data and their application on measured oxygen isotope signatures of a fish otolith and a marine bivalve shell are presented and compared the first method is a flexible approach using a linear interpolation between carefully selected temporal reference points for recalculating ontogenetic growth effects with an optional extension accounting for seasonal growth oscillations the second approach uses the seasonally oscillating von bertalanffy growth function parameterized based on the oxygen isotope record to reconstruct the underlying growth model and reconstruct thereby its temporal framework using these methods we re align 18 o based water temperature records of a carlarius heudelotii otolith and a venus crebrisulca shell with measured sea surface temperature time series and compare the resulting correlation as well as the different underlying growth models our results show that both methods represent useful tools for the temporal alignment of sclerochronological records however underlying growth models strongly differ depending on the temporal alignment method and the parameters used for the reconstruction of the temporal framework this underlines the importance of a careful selection of a particular alignment method depending on the complexity of distortion due to seasonal and ontogenetic growth trajectories moreover we show that both organisms represent reliable paleoenvironmental archives providing sub seasonally resolved water temperature records

shell sclerochronology and stable isotopes of the bivalve anomalocardia flexuosa linnaeus 1767 from southern brazil implications for environmental and archaeological studies abstract this study presents the first stable isotopic and sclerochronological calibration of the bivalve anomalocardia flexuosa linnaeus 1767 in relation to environmental variables in a subtropical coastal area of southern brazil we investigate incremental shell growth patterns and 18o and 13c values of modern specimens collected alive from the laguna lagoonal system lls shells of anomalocardia flexuosa are also one of the main biological components of pre columbian archaeological shell mounds and middens distributed along the brazilian coastline we therefore selected archaeological specimens from a local late holocene shell mound cabecuda to compare their stable carbon and oxygen isotope values with those of modern specimens shell growth increments 18o and 13c values respond to a complex of environmental conditions involving for example the effects of temperature and salinity the isotopic information extracted from archaeological specimens from cabecuda shell midden in the lls indirectly indicates that environmental conditions during the late holocene were different from present day in particular intra shell 18o and 13c values of archaeological shells reveal a stronger marine influence at 3 ka cal bp which is in contrast to the seasonal freshwater seawater balance that currently prevails at the lls

coralline algal growth increment widths archive north atlantic climate variability over the past decade coralline algae have increasingly been used as archives of paleoclimate information encrusting coralline algae which deposit annual growth increments in a high mg calcite skeleton are amongst the longest lived shallow marine organisms in fact a live collected plant has recently been shown to have lived for at least 850 years based on radiometric dating while a number of investigations have successfully used geochemical information of coralline algal skeletons to reconstruct sea surface temperatures less attention has been paid to employ growth increment widths as a temperature proxy here we explore the relationship between growth and environmental parameters in clathromorphum compactum collected in the subarctic northwestern atlantic results indicate that growth increment widths of individual plants are poorly correlated with instrumental sea surface temperatures sst however an averaged record of multiple growth increment width time series from a regional network of c compactum specimens up to 800 km apart reveals strong correlations with annual instrumental sst since 1950 hence similar to methods applied in dendrochronology averaging of multiple sclerochronological records of coralline algae provides accurate climate information a 115 year growth increment width master chronology created from modern collected and museum specimens is highly correlated to multidecadal variability seen in north atlantic sea surface temperatures positive changes in algal growth anomalies record the well documented regime shift and warming in the northwestern atlantic during the 1990s large positive changes in algal growth anomalies were also present in the 1920s and 1930s indicating that the impact of a concurrent large scale regime shift throughout the north atlantic was more strongly felt in the subarctic northwestern atlantic than previously thought and may have even exceeded the 1990s event with respect to the magnitude of the warming

seasonal temperature variability of the neoglacial 3300 2500 bp and roman warm period 2500 1600 bp reconstructed from oxygen isotope ratios of limpet shells patella vulgata northwest scotland abstract seasonal sea surface temperature variability for the neoglacial 3300 2500 bp and roman warm period rwp 2500 1600 bp which correspond to the bronze and iron ages respectively was estimated using oxygen isotope ratios obtained from high resolution samples micromilled from radiocarbon dated archaeological limpet patella vulgata shells the coldest winter months recorded in neoglacial shells averaged 6 6 0 3 c and the warmest summer months averaged 14 7 0 4 c one neoglacial shell captured a year without a summer which may have resulted from a dust veil from a volcanic eruption in the katla volcanic system in iceland rwp shells record average winter and summer monthly temperatures of 6 3 0 1 c and 13 3 0 3 c respectively these results capture a cooling transition from the neoglacial to rwp which is further supported by earlier studies of pine history in scotland pollen type analyses in northeast scotland and european glacial events the cooling transition observed at the boundary between the neoglacial and rwp in our study also agrees with the abrupt climate deterioration at 2800 2700 bp also referred to as the subboreal subatlantic transition and therefore may have been driven by decreased solar radiation and weakened north atlantic oscillation conditions

origin and tectonic setting of some melange units in turkey a geologic study of three different melange belts in turkey revealed that the melange units in these belts were formed by gravity sliding in basins underlain by continental basement rather than by tectonic crushing in trenches mafic volcanic activity is a characteristic feature of such basins which are located on continental margins adjacent to tectonically active belts the peridotite and gabbro blocks of the melange units were transported but some of the basalts radiolarites and mudstones originated within the basins and hence are not part of an ophiolite suite

geochemical perspectives on coral mineralization corals open an exceptional window into many phenomena of geological geochemical climatic and paleontological interest from the paleozoic to the present corals provide some of the finest high resolution archives of marine conditions corals are likewise exceptional for chronometric purposes and even the terrestrial 14c timescale has now been calibrated against coral 230th 234u corals also represent a testing ground for basic ideas about mineralogy and geochemistry the shapes sizes and organization of skeletal crystals have been attributed to factors as diverse as mineral supersaturation levels and organic mediation of crystal growth the coupling between calcification and photosynthesis in symbiotic corals is likewise attributed to everything from photosynthetic alkalinization of the water to efforts by the coral to prevent photosynthetic alkalinization corals also leave a significant geochemical imprint on the oceans their aragonite skeletons accept about 10 times more strontium than does calcite hence the proportion of marine aragonite precipitation affects the oceanic chemical balance biological carbonates represent the biosphere s largest carbon reservoir hence calcareous organisms affect the ocean s ph co2 content and ultimately global temperatures through the greenhouse gas connection finally corals present some geochemical puzzles for ecology and conservation how do symbiotic corals obtain nutrients in some of the most nutrient deficient parts of the planet are global geochemical changes partially responsible for the widespread declines in coral reefs during recent decades we will address many of these issues but will concentrate on coral skeletal structure and calcification mechanism these topics bear most directly on the biomineralization process and generally affect the choice of skeletal materials and analytical techniques used in geochemical investigations the coral reef is probably the planet s most spectacular biomineralization product these grand and complex ecosystems build on the accumulated skeletal debris of countless generations of organisms especially calcareous algae and symbiotic

assessment of ba ca in arctica islandica shells as a proxy for phytoplankton dynamics in the northwestern atlantic ocean abstract despite its major role as a global climate regulator little is known about the recent evolution of the north atlantic ocean especially prior to the fifties principally because of the lack of long term instrumental data moreover the north atlantic ocean is undergoing rapid changes at the physical scale leading to modifications at the biological scale increasing interest to monitor the environment the phytoplankton is the base of the ocean life and its perturbation can lead to further changes in the food chain recording its dynamics implies to observe both its spatial and temporal variations this study brings forward the use of the ba ca ratio from shells of the long living bivalve arctica islandica collected in the northwestern atlantic ocean near saint pierre and miquelon spm as a recorder of the past and present phytoplankton dynamics a high inter and intra reproducibility and synchrony between ba cashell profiles were demonstrated allowing the reconstruction of a 124 years annually resolved ba cashell master chronology from 1893 to 2016 this master chronology was positively correlated to the surface chlorophyll a measured by satellite sensor at regional around spm and global scales northwestern atlantic

sclerochronology and geochemical variation in limpet shells patella vulgata a new archive to reconstruct coastal sea surface temperature 1 climate archives contained in shells of the european limpet patella vulgata accumulated in archaeological deposits can potentially provide much needed information about holocene environmental change in midlatitude coastal areas before reconstructing climate information preserved in these zooarchaeological records we studied the controls on oxygen and carbon isotope ratios 18o and 13c respectively in modern specimens we tested the hypothesis that p vulgata precipitates its shell in isotopic equilibrium with the ambient water by comparing 18oshell with predicted values predicted 18oshell was constructed using observed sea surface temperature sst records and the equilibrium fractionation equation for calcite and water we assumed a constant 18owater value of 0 10 vsmow based on published regional measurements comparison of 18oshell with predicted values revealed that 18oshell values were higher than expected by 1 01 0 21 consequently estimated sst calculated from 18oshell was 4 2 2 3 c lower than observed sst however because of the relatively uniform offset between observed and expected 18o an adjustment can be made to account for this predictable vital effect thus past climate can be reliably reconstructed using this temperature proxy once the offset is taken into account 13c values have a similar cyclicity to the 18o variation and therefore vary seasonally however 13c is slightly out of phase relative to 18o an overall negative shift in 13cshell over the lifetime of the individual indicates a vital effect associated with ontogeny further study of environmental and ecological factors that influence shell 13c is required to evaluate fully the potential of carbon isotope ratios as a useful environmental proxy

shell morphometry of seven limpet species from coastal shell middens in southern africa measurements of shell parts and features elements of marine limpets can be used to derive morphometric equations for estimating total shell lengths this is demonstrated for seven limpet species commonly found on the southern african coast the equations can be used to reconstruct whole shell lengths for highly fragmented limpet samples in prehistoric shell middens a linear regression model is based on measurements of all shell elements resulting in high coefficients of determination with excellent predictive power in most cases these morphometric equations would enable archaeologists to derive more metrical information from fragmentary archaeological material than was previously the case we also present a case study where morphometric equations of two limpet species are applied to an archaeological sample from the south african west coast for the purpose of investigating possible biases in limpet shell preservation we conclude that small whole limpet shells survive longer than the bigger ones in this particular case but that many more such case studies need to be conducted in order to fully understand differential preservation of southern african limpet shells in archaeological sites

u series and radiocarbon dates on mollusc shells from the uppermost layer of the archaeological site of khb 1 ra s al khabbah oman the archaeological site of khb 1 oman has been investigated in order to improve the chronological knowledge of the site which is dated to the beginning of the fourth millennium b c on the basis of the archaeological context mollusc shells of the genus anadara coming from the uppermost layers of the site have been dated using two different methods radiocarbon and u series technique the results of the two techniques date the last occupational phase of the site from the end of the fourth millennium b c to the beginning of the third millennium b c

observations of infrasound and subsonic disturbances related to severe weather summary during the past 10 years the geoacoustics group of noaa s wave propagation laboratory studied travelling low frequency pressure variations related to thunderstorms and severe weather two general categories of waves were associated with severe weather conditions subsonic pressure disturbances and infrasonic waves with acoustic velocities the low frequency pressure variations were measured at the earth s surface using microphone arrays located at times thousands of kilometres from the severe weather disturbance the radiated infra sound was related to thunderstorms penetrating the tropopause and spectral analyses were performed on several signals possible practical applications to storm warning and classification are discussed for both infrasound and subsonic pressure disturbances past measurements of these signals are reviewed

coupled north atlantic slope water forcing on gulf of maine temperatures over the past millennium to investigate ocean variability during the last millennium in the western gulf of maine gom we collected a 142 year old living bivalve arctica islandica l in 2004 and three fossil a islandica shells calibrated 14cams 1030 78 ad 1320 45 ad 1357 40 ad for stable isotope and growth increment analysis a statistically significant relationship exists between modern gom temperature records shell isotope derived 30 m r 0 79 p 0 007 prince 5 50 m r 0 72 p 0 019 boothbay harbor sst r 0 76 p 0 011 and labrador current lc transport data from the eastern newfoundland slope during 1993 2003 in all cases as lc transport increased gom water temperatures decreased the following year decadal trends in the north atlantic oscillation nao and the atlantic multidecadal oscillation amo influence gom water temperatures in the most recent period with water temperatures decreasing during nao and amo negative modes most likely linked to lc transport and gulf stream interaction mean shell derived isotopic changes 18oc during the last 1 000 years were 0 47 and likely reflect a 1 2 c cooling from 1000 ad to present based on these results we suggest that observed cooling in the gom during the last millennium was due to increased transport and or cooling of the lc and decreased gulf stream influence on the gom

investigating δ 18 o of turbo sarmaticus l 1758 as an indicator of sea surface temperatures abstract the large marine gastropod turbo sarmaticus was and still is an important food item for coastal foragers along the south coast of south africa opercula of this species are well preserved in both holocene and pleistocene archaeological sites offering the opportunity to reconstruct past sea surface temperatures from 18o of shell carbonate over much of the last glacial cycle we have analysed 18o and 13c in 16 opercula and one shell of modern animals collected alive from an area with good sst records in order to explore how reliably this species records water temperature through the year and to investigate possible vital effects that may influence the isotope record we find that t sarmaticus deposits aragonite in both operculum and shell in oxygen isotopic equilibrium with seawater operculum 18o values of this species reliably reflect water temperatures between c 14 and 24 c although they do not always capture temperature extremes especially in winter likely due to slower growth under stressful growth conditions these thresholds probably alter according to factors such as variations in nutrient supply the averaged maximum and minimum values across the set of sixteen serially sampled opercula very closely approximate the temperatures of the warmest and coolest months and therefore provide a good measure of the seasonal temperature range and of mean annual sst 18o of edge increments can to some extent be used to indicate season of collection within the broad categories of warmer cooler seasons

unionid shells hyriopsis cumingii record manganese cycling at the sediment water interface in a shallow eutrophic lake in china lake taihu abstract aquatic eutrophication is becoming a serious environmental problem throughout the world the utility of bivalves as bio filters to improve water quality and reduce algal blooms has been widely acknowledged but the potential usefulness of bivalve shells as retrospective monitors of eutrophication induced environmental change has received little attention here we present the first multi year high resolution mn ca shell records of the freshwater mussel hyriopsis cumingii lea 1852 from a shallow eutrophic lake lake taihu china mn ca shell time series of the two studied shells exhibit a high degree of synchrony after being placed in a precise temporal context by means of growth pattern analysis there is a large inter annual variability of mn ca shell records during 2011 2015 with the highest value occurring in 2013 mn ca shell also displays a pronounced intra annual variability with maxima consistently occurring during late spring early summer the high reproducibility of mn ca shell time series among contemporaneous specimens highlights the existence of strong environmental rather than biological control on the incorporation of mn into the shells in particular the striking feature of late spring early summertime mn ca shell maxima is synchronous with the occurrence of reducing conditions beneath the sediment water interface swi the latter results in substantial increases of biologically available mn 2 in the sediment pore water and organic particles the element being rapidly taken up from these sources by the mussels with subsequent incorporation of mn into their shells therefore mn ca shell can potentially serve as a high resolution proxy of the mobility of mn at the swi as demonstrated by the present study documenting and understanding geochemical properties of bivalve shells can help to retrospectively monitor eutrophication induced environmental change in aquatic ecosystems

calibrating the element composition of donax deltoides shells as a palaeo salinity proxy abstract bivalve shell chemistries provide valuable insights into past environments if relationships between shell chemistry and environmental conditions are known this study assessed the suitability of goolwa cockle donax deltoides shell element composition as an environmental proxy for southern australia a region lacking high resolution environmental records cockles were collected along an environmental gradient and the element composition of corresponding water and shell samples were quantified using a combination of icp aes and icp ms for water samples and la icp ms for shells of the elements analysed ba ca li ca and mg ca in shells reflected ambient water chemistries shell ba ca concentrations showed a significant negative relationship with recorded salinities and a positive non significant trend was observed between mg ca and water temperature further assessment of environmental and biological controls on element incorporation are required however ba ca in d deltoides shells appears a suitable palaeo salinity tool and has the potential to provide an easily accessible and valuable proxy to gain insights into past environmental conditions over extensive time scales

marine mollusc exploitation in mediterranean prehistory an overview abstract marine molluscs have been recovered from sites around the mediterranean sea dating as far back as the lower palaeolithic when hominins might have started consuming them ca 300 ka during the middle palaeolithic and the early upper palaeolithic humans homo neanderthalensis and homo sapiens ate molluscs at many sites across the mediterranean at least as early as the last interglacial although the scale of this exploitation is still unclear due to biases produced in the coastal archaeological record by late glacial and post glacial sea level rise the exploitation of marine molluscs apparently increased in the late glacial and early holocene when humans collected them in relatively large quantities and from all available ecosystems the consumption of shellfish and of other small animals aquatic and continental probably contributed to the success of the flexible and opportunistic subsistence strategies adopted by mediterranean hunter gatherers for much of prehistory this is particularly evident in later foraging economic systems i e late upper palaeolithic and mesolithic in which coastal resources probably acted as buffers against the negative outcomes of environmental and anthropogenic impacts on available resources

mississippian paleocean chemistry from biotic and abiotic carbonate muleshoe mound lake valley formation new mexico u s a abstract it has been proposed that phanerozoic variation in the mg ca ratio of seawater has resulted in variation in the primary mineralogies of shallow water carbonates between aragonite and calcite dominated seas to test this hypothesis this study estimates the mississippian oceanic mg ca and sr ca ratios from the composition of marine carbonate cements and crinoidal carbonate both of which have been suggested to faithfully record seawater chemistry the early mississippian tournaisian visean muleshoe mound lake valley fm alamogordo nm u s a lends itself well to this endeavor because it contains abundant crinoids and marine carbonate cement stable isotope and elemental analyses as well as cathodoluminescence characteristics elucidate the diagenetic history of the bioherm and identify the least diagenetically altered materials for reconstruction of paleoseawater chemistry isotopic analyses document two diagenetic trends one meteoric and one burial diverging from values similar to literature estimates of mississippian marine calcite 1 5 18o 4 5 13c the burial diagenetic trend follows from this origin to more negative oxygen values 7 18o 3 13c the meteoric diagenetic trend is defined by a meteoric calcite line at 3 18o similarity of non luminescent marine cement and non luminescent crinoid isotopic and elemental compositions suggests that crinoidal carbonate was completely replaced by cement in the marine environment average elemental ratios for least altered marine cements are mg ca 11 mmol mol sr ca 0 2 mmol mol mn ca 0 2 mmol mol and fe ca 0 4 mmol mol early mississippian seawater is estimated to have had a mg ca ratio of 0 2 0 3 mol mol this mg ca ratio is compatible with the early mississippian being an interval of calcite sea conditions and compares well with the devonian estimate from marine cements 0 5 though it is 5 10 times lower than estimates from mass balance modeling the sr ca for early mississippian seawater was between 0 5 and 0 9 mmol mol which is much lower than previous estimates of 6 mmol mol from brachiopod calcite and argues for the development of a sr sink aragonite in the latest devonian to earliest mississippian

shell oxygen isotope values and sclerochronology of the limpet patella vulgata linnaeus 1758 from northern iberia implications for the reconstruction of past seawater temperatures abstract understanding environmental conditions faced by hunter fisher gatherers during the pleistocene and holocene and interpretation of subsistence strategies social organisation and settlement patterns are key topics for the study of past human societies in this respect oxygen isotope values 18o of mollusc shell calcium carbonate can provide important information on palaeoclimate and the seasonality of shell collection at archaeological sites in this paper we tested p vulgata shells from northern iberia as a paleoclimate archive through the study of shell oxygen isotope values and sclerochronology of modern samples results showed that limpets formed their shells close to isotopic equilibrium with an average offset between measured and predicted values of 0 36 this offset is significantly reduced with respect to those reported in previous studies probably due to the use of highly resolved data on the isotopic composition of the water when calculating predicted values despite large intra specific variability shell growth patterns of p vulgata revealed a common pattern of higher growth in spring and a growth cessation slowdown in summer and winter the seasonal growth cessation slowdown did not exceed three months therefore a correct interpretation of the season of shell collection is still possible reconstructed seawater temperature exhibited a high correlation with instrumental temperature r2 0 68 to 0 93 p

climate variability over the last 35 000 years recorded in marine and terrestrial archives in the australian region an oz intimate compilation abstract the australian region spans some 60 of latitude and 50 of longitude and displays considerable regional climate variability both today and during the late quaternary a synthesis of marine and terrestrial climate records combining findings from the southern ocean temperate tropical and arid zones identifies a complex response of climate proxies to a background of changing boundary conditions over the last 35 000 years climate drivers include the seasonal timing of insolation greenhouse gas content of the atmosphere sea level rise and ocean and atmospheric circulation changes our compilation finds few climatic events that could be used to construct a climate event stratigraphy for the entire region limiting the usefulness of this approach instead we have taken a spatial approach looking to discern the patterns of change across the continent the data identify the clearest and most synchronous climatic response at the time of the last glacial maximum lgm 21 3 ka with unambiguous cooling recorded in the ocean and evidence of glaciation in the highlands of tropical new guinea southeast australia and tasmania many terrestrial records suggest drier conditions but with the timing of inferred snowmelt and changes to the rainfall runoff relationships driving higher river discharge at the lgm in contrast the deglaciation is a time of considerable south east to north west variation across the region warming was underway in all regions by 17 ka post glacial sea level rise and its associated regional impacts have played an important role in determining the magnitude and timing of climate response in the north west of the continent in contrast to the southern latitudes no evidence for cooling during the younger dryas chronozone is evident in the region but the antarctic cold reversal clearly occurs south of australia the holocene period is a time of considerable climate variability associated with an intense monsoon in the tropics early in the holocene giving way to a weakened monsoon and an increasingly el nino dominated enso to the present the influence of enso is evident throughout the southeast of australia but not the southwest this climate history provides a template from which to assess the regionality of climate events across australia and make comparisons beyond our region

new research in the methods and applications of sclerochronology abstract because the instrumental record is short and does not extend to periods before the initiation of significant human impacts full understanding of the processes and dynamics involved in the modern phase of very rapid global change depends on the interpretation of high resolution and precisely dated proxy archives the identification of very long lived species of bivalve mollusc in the extratropical marine environment has been a crucial recent advance these molluscs form patterns of periodic usually annual banding in their shells that are synchronous within populations so that long centennial and millennial stacked chronologies can be built by crossdating from live collected to fossil shells the variable growth rates and precisely dated geochemical data from the shell material provide long term real world data that can in principle be used to constrain climate models and to define long baselines for environmental monitoring however the signals in these data usually result from the complex interaction of multiple influences and the deconvolution and understanding of these influences is a major target of the scientific field of sclerochronology this special issue presents some of the latest research into the sclerochronology of mollusc shells it includes contributions to our understanding of shell growth including the identification of endogenous non environmental growth rhythms that persist throughout ontogeny and analysis in two papers of variability through ontogeny in the season of growth and the implications of such variability for temperature reconstruction one paper presents a new network of bivalve chronologies for uk waters with a 200 year seawater temperature reconstruction three papers cover trace element geochemistry including a novel approach to sampling for la icp ms that enables giant clam shells to be sampled at daily resolution an attempt to identify an independent temperature proxy for coastal waters using limpet shells and a detailed study of the drivers of variability in sr ca and ba ca ratios one study looks at shell microstructure as a temperature proxy finding a coherent temperature response in the shape of the prisms

oceanography in northwestern europe during the last interglacial from intrashell δ18o ranges in littorina littorea gastropods abstract coastal sea surface temperature sst and sea surface salinity sss including seasonality in northwest nw europe during the early phase of the eemian interglacial ca 125 ka ago were reconstructed from littorina littorea common periwinkle gastropods the results were based on intra annual 18o analyses in recent and fossil shells mainly originating from the sea of kattegat sweden and the english channel united kingdom and confined to intertidal settings the eemian l littorea shells indicated annual ssts in the range 8 18 c for the english channel and 8 26 c for kattegat all specimens from the eemian sites experienced summer ssts of ca 1 3 c above recent conditions the estimated winter sst in the english channel during the eemian was comparable to modern measurements of ca 8 c however the kattegat region displayed eemian winter sst approximately 8 c warmer than today and similar to conditions in the western english channel the recent fossil isotope analogue approach indicated high sss above 35 practical salinity units psu for a channel south of england in full contact with the north atlantic ocean during the last interglacial in addition the kattegat shells indicated a sss of ca 29 psu which points out a north sea affinity for this region during the eemian

sea surface temperature estimates from the southwest pacific based on planktonic foraminifera and oxygen isotopes planktonic foraminiferal census data were collected on 34 surficial sediment samples from east of new zealand sea surface temperature estimates were derived from the data using the modern analogue technique mat and compared to data from climap s fa 20 equation they were also computed from oxygen isotope analyses of globigerina bulloides the temperature estimates compared well between the three methods and were found to correlate closely with the appropriate seasonal sea surface temperature as measured by satellite the foraminiferal assemblages and derivative temperatures clearly identify the major watermasses and oceanic fronts in the region and thus can be applied to palaeoceanographic analysis of southwest pacific sediments

isotope paleontology growth and composition of extant calcareous species abstract isotope paleontology uses the isotopic composition of fossil remains of organisms to make inferences about the physical surroundings of growth of the organisms especially temperature and to obtain clues about life history and modes of growth in calcareous fossils oxygen isotopes are mainly used in the former and carbon isotopes in the latter however since physical surroundings and organism response are intimately associated both types of information are contained in each of the isotopic signals to explore the potential of isotope paleontology and to provide a basis for reconstruction a broad range of extant organisms has been studied taking the pioneering work of epstein and associates as a starting point results are summarized for a representative sampling of these studies with emphasis on work at the laboratories of the authors from the mid seventies to the present the organisms considered are nannoplankton benthic algae planktonic and benthic deep sea foraminifera larger foraminifera sponges corals bryozoans polychaetes arthropods bivalves gastropods cephalopods and vertebrates fish otoliths the survey broadly suggests that regarding oxygen isotopes materials tend to be precipitated close to equilibrium with the surrounding seawater as postulated by urey and that for carbon isotopes disequilibrium is the rule life spans growth rates differential seasonal growth and age of reproductive activity can be extracted under favorable circumstances from individual shells and skeletal parts in detail the interpretation of isotope records of individual shells is quite complicated and simple models will fail to give satisfactory results in many or most cases

high resolution analysis of trace elements in crustose coralline algae from the north atlantic and north pacific by laser ablation icp ms we have investigated the trace elemental composition in the skeleta of two specimens of attached living coralline algae of the species clathromorphum compactum from the north atlantic newfoundland and clathromorphum nereostratum from the north pacific bering sea region amchitka island aleutians samples were analyzed using laser ablation inductively coupled plasma mass spectrometry la icp ms yielding for the first time continuous individual trace elemental records of up to 69 years in length the resulting algal mg ca sr ca u ca and ba ca ratios are reproducible within individual sample specimens algal mg ca ratios were additionally validated by electron microprobe analyses amchitka sample algal sr ca u ca and ba ca ratios were compared to algal mg ca ratios which previously have been shown to reliably record sea surface temperature sst ratios of sr ca from both clathromorphum species show a strong positive correlation to temperature dependent mg ca ratios implying that seawater temperature plays an important role in the incorporation of sr into algal calcite linear sr ca sst regressions have provided positive but weaker relationships as compared to mg ca sst relationships both algal mg ca and sr ca display clear seasonal cycles inverse correlations were found between algal mg ca and u ca ba ca and correlations to sst are weaker than between mg ca sr ca and sst this suggests that the incorporation of u and ba is influenced by other factors aside from temperature

new research on the development of high resolution palaeoenvironmental proxies from geochemical properties of biogenic carbonates abstract geochemical signatures from biogenic carbonates are being increasingly employed as palaeoenvironmental proxies in turn many of these proxy archives including mollusc shells corals and otoliths have periodic growth structures which allow the reconstruction of chronologically constrained records of palaeoenvironmental variability at unparalleled high temporal resolution studying the growth and chemistry of these periodic growth structures is known as sclerochronology biogenic hard parts accumulate in geological or archaeological deposits and can be directly dated using radiometric and racemisation methods they therefore offer the opportunity for high resolution palaeoenvironmental reconstructions across many time intervals all over the globe such data are important for several reasons 1 understanding past climate and environmental change provides a means of contextualising current and future climate change and ecological disturbance 2 high resolution palaeoenvironmental records are essential for constraining testing and validating global and regional numerical climate models 3 palaeoenvironmental records from biogenic carbonates can provide an environmental framework from which to understand the behavioural changes and interactions of peoples with their environment however inter and intra species differences in growth rate physiology and environmental response can cause variations in the chemical profiles of biogenic carbonates before geochemical data is employed for palaeoenvironmental reconstructions it is thus necessary to examine modern specimens of the target species or related taxa to understand how geochemical variations are influenced by local environmental conditions kinetic and vital effects this allows the generation of quantitative and more reliable proxy records of environmental change this special issue brings together the latest research on palaeoenvironmental proxy development and validation in biogenic carbonates it includes studies on marine freshwater and estuarine organisms molluscs corals and echinoderms and on traditional as well as novel geochemical proxies the papers presented here include in situ field calibration studies laboratory growth experiments as well as methodological studies into the effects of sampling and pre treatment the geographical scope is broad encompassing both the northern and southern hemispheres including south africa south america australia asia the mediterranean sea and the north atlantic

paleoenvironmental proxies in echinoid spines eucidaris galapagensis doderlein 1887 along a natural water temperature gradient abstract the use of paleoenvironmental proxies such as oxygen isotopes in echinoderm skeletons has been a matter of controversial debate many previous studies showed a variety of environmental as well as biological processes causing deviations from equilibrium incorporation of geochemical proxies during the formation of echinoderm skeletons however given the global distribution of echinoids their fast spine growth and their occurrence throughout the entire phanerozoic species specific calibrations of geochemical proxies in echinoid spines can disclose a valuable bio archive for reconstructing ancient environmental conditions throughout earth s history if samples are adequately preserved in the sedimentary record here we present data on oxygen isotopes 18 o carbon isotopes 13 c and mg ca ratios measured in eucidaris galapagensis doderlein 1887 spines which were sampled along the natural water temperature gradient of the galapagos archipelago we found a negative correlation of 18 o calcite with ambient water temperature following the equation 1000 ln 23 03 10 3 t 1 k 47 90 we also found 13 c calcite be positively correlated with water temperature following the equation 13 c calcite vpdb 47 585 0 164 t k mg ca ratios also showed a significant correlation with water temperature however with a low correlation coefficient the large scatter of 18 o calcite values within the upwelling region indicates higher growth rates during seasons of colder water temperatures considering this and the observed steeper slope in the temperature 18 o calcite relationship our data suggest that the common assumption of respiration affecting oxygen isotope fractionation does not apply for the tropical species e galapagensis overall our data show that e galapagensis spines represent valuable paleoenvironmental archives which might have the potential to provide sub annually resolved water temperature records if spine architecture and growth pattern are well constrained

reproducibility of trace element time series na ca mg ca mn ca sr ca and ba ca within and between specimens of the bivalve arctica islandica a la icp ms line scan study abstract trace element time series in bivalve mollusk shells and other biogenic materials can potentially serve as environmental proxies yet the applicability of element to calcium ratios is often challenging because non environmental factors such as vital effects distort or mask environmental signals if a trace element time series is driven by an environmental factor it should be reproducible within and between coeval specimens of the same species in the present study we tested whether time series of trace element to calcium ratios can be reproduced within and between coeval specimens of the bivalve arctica islandica and thus whether an external signal is encoded in the temporal variations of trace elements along the shells we determined the concentration of sodium magnesium manganese strontium and barium by means of la icp ms in line scan mode in the hinge area of seven specimens from the isle of man the gulf of maine and iceland in each specimen the element composition was determined along two replicate line scans to gauge intra specimen reproducibility the degree to which trace element time series can be reproduced was inferred from linear regression analysis and equaled on average 95 4 for ba ca 82 27 for mg ca 83 18 for sr ca 74 23 for mn ca and 22 4 for na ca ratios values correspond to coefficients of determination of the linear regression analysis expressed in percent the synchrony of ba ca time series between contemporaneous specimens from the same habitat has already been demonstrated in previous studies here we observed common high frequency variations i e peaks among coeval a islandica from the same site for mg ca sr ca mn ca and na ca ratios especially among specimens of similar ontogenetic age and with similar shell growth patterns the results of the present study should be considered in interpretations of trace element time series in bivalve shells as they can help to improve environmental and climate reconstructions

non linear variation with salinity of sr ca and mg ca ratios in water and aragonitic bivalve shells and implications for paleosalinity studies abstract fresh water and sea water usually differ considerably in their sr ca and mg ca ratios this suggests that these ratios in fossil shells could be used to determine paleosalinities calculation of the sr ca and mg ca ratios in mixtures of sea water and average fresh water using a mixing equation shows that the ratios first increase rapidly with salinity to about 100 but subsequently remain nearly constant the source of most of the ca sr and mg in mixtures of fresh and sea water is the sea water thus except at low salinities the trace element to ca ratio of mixtures differs little from that in sea water analysis both of waters across a spectrum of salinities and of aragonitic mollusc shells growing in water of various salinities conforms to the predicted pattern however trace element to ca ratios offer potential for paleosalinity determination in waters of salinity below about 100

coralline red algae as high resolution climate recorders most high resolution proxy based paleoclimate research has concentrated on tropical oceans while mid and high latitude marine regions have received less attention despite their importance in the global climate system at present sclerochronological analyses of bivalve mollusks supply the bulk of annual to subannual resolution extratropical marine climate data even though interpretation is complicated by a slowdown of growth with increasing shell age hence in order to address the need for additional high resolution proxy climate data from extratropical regions we conducted the first year long in situ field calibration of the coralline red alga clathromorphum compactum in the gulf of maine united states coralline red algae are widely distributed in coastal regions worldwide and individual calcified plants can live continuously for several centuries in temperate and subarctic oceans stable oxygen isotopes extracted at subannual resolution from growth increments of monitored specimens of c compactum relate well to in situ measured sea surface temperatures during the may to december calcification period highlighting the suitability of coralline red algae as an extratropical climate archive furthermore there is a strong correlation between a 30 yr 18 o record of c compactum and an instrumental sea surface temperature record r 0 58 p 0 0008 and a proxy reconstruction derived from the bivalve arctica islandica collected in the central gulf of maine r 0 54 p 0 002

climate records from a bivalved methuselah arctica islandica mollusca iceland we measured annual shell growth rates of a 374 year old radiometrically confirmed bivalve mollusk specimen of arctica islandica linnaeus this bivalve represents the oldest ever reported individual animal in addition we analyzed 1051 individual powder samples from ontogenetic years two to 40 80 of the entire shell height for isotope analyses oxygen and carbon isotopes exhibit clear intra annual cycles the highest measured carbon isotope values on average 2 73x occurred during summer i e during maximum primary productivity the d 18 oaragonite derived temperature time series cover the period of ad 1496 1533 temperatures calculated from oxygen isotopes ranged from 4 5 to 9 3 8c and exhibit a mean value of 6 2 8c the latter coincides well with the 1854 2003 mean value of 6 81 8c for sea surface temperature between february and september growing season of a islandica neither oxygen nor carbon isotopes exhibit age related unidirectional trends however d 13 caragonite and d 18 oaragonite values fluctuated at decadal periods of four six and eight to nine years nao type periods as well as 12 14 years which may represent teleconnections to cycles in the tropical atlantic annual shell growth is positively correlated to intra annual d 18 oaragonite minima i e warm summer temperatures r 2 0 34 and to intra annual d 13 caragonite minima higher food supply r 2 0 42 using a linear multiregression model 65 of the variation in annual shell growth can be explained by summer temperature and food supply the formation of extremely narrow annual increments coincides with major volcanic eruptions e g tambora 1815 a period of extremely variable growth occurred during the culmination of the little ice age in iceland between ca ad 1550 and 1620 shell growth during ad 1765 1780 however was characterized by very little year to year variability probably as the result of extremely mild climate near the end of the little ice age this study demonstrates that shells of a islandica provide

contrasting shell growth strategies in two mediterranean bivalves revealed by oxygen isotope ratio geochemistry the case of pecten jacobaeus and glycymeris pilosa abstract high resolution stable isotope ratio data 18 o 13 c were used to study growth strategies of two bivalve species pecten jacobaeus calcitic shell and glycymeris pilosa aragonitic shell from the north adriatic sea the principal objectives of this study were to identify the period of the year when the growth line is formed in the shell of two target species to identify the main growing season of these two species to identify the environmental drivers of shell growth and to evaluate the potential applicability of 18 o and 13 c values for the reconstruction of environmental variability samples were collected from the north adriatic sea by commercial bean trawl p jacobaeus december 2013 and january 2014 n 4 and scuba diver glycymeris pilosa march 2016 n 3 samples for the oxygen 18 o and carbon 13 c isotope composition of the calcium carbonate were collected by drilling the outer shell layer across several annual cycles temporal and spatial temperature and salinity values inside the investigated area were simulated using the 3d numerical ocean model roms the 18 o cycles corresponded to the number of seasonal growth marks observed on the external shell surface of both target species thereby confirming the annual periodicity of these growth patterns in february 2012 extreme cooling of the water column accompanied by dense water formation occurred in the adriatic sea an event recorded by p jacobaeus shells this study indicates that p jacobaeus and g pilosa have contrasting shell growth strategies pecten jacobaeus grows during winter and slows shell growth during the warmest part of the year and thereby may be an interesting archive for winter conditions due to its longevity and continuous growth during the warmest part of the year g pilosa is a promising archive for the reconstruction of summer seawater temperatures

oxygen isotopes from phorcus osilinus turbinatus shells as a proxy for sea surface temperature in the central mediterranean a case study from malta abstract the marine topshell phorcus osilinus turbinatus is a common component of many archaeological sites in the mediterranean this species has been successfully used as a palaeoclimate proxy in italy to test whether 18 o from p turbinatus shells can serve as a reliable palaeoclimate archive for other regions of the mediterranean we collected live p turbinatus from the northeast coast of malta each month for a year the 18 o shell values of the outermost growth increments of these live collected shells ranged between 0 4 and 2 4 these values correspond to growing temperatures calculated from shell edge 18 o of between 15 c and 27 c calculated shell edge sea surface temperatures are highly correlated with instrumental records of sea surface temperature recorded over the period of collection the individuals analysed for this study are smaller than p turbinatus from populations studied elsewhere in the mediterranean nonetheless 18 o shell provides a robust record of sea surface temperatures suggesting that smaller younger shells in archaeological deposits can still provide reliable palaeothermometry records this study extends the upper growth limit p turbinatus by 2 c compared with the previous studies of p turbinatus in the mediterranean and suggests that contrary to the previous studies growth shutdown does not occur in all p turbinatus when sea surface temperatures exceed 25 c this may reflect the higher sample resolution that can be obtained from smaller faster growing shells or it may reflect actual higher growth tolerances of p turbinatus populations in malta by showing that p turbinatus precipitate their shells in 18 o equilibrium with surrounding sea water this study reinforces the potential for the stable isotope chemistry of p turbinatus shells preserved in mediterranean archaeological sites to provide a window into the climate and seasonality regimes of the past

further amino acid racemisation evidence for glacial age multiple lowstand deposition on the new south wales outer continental shelf southeastern australia abstract amino acid racemisation aar analyses total acid hydrolysate on the fossil bivalve molluscs pecten fumatus and glycymeris radians from 10 vibracores from the new south wales continental shelf in present water depths ranging between 123 and 152 m below present sea level and extending some 300 km of latitude provide further evidence for multiple lowstand deposition at times of glacial maxima the extent of racemisation as determined for the amino acids alanine ala aspartic acid asp leucine leu and valine val indicate that the fossil molluscs plot into three principal aminogroups of contrasting age and in general accord with results previously obtained from three vibracores for the molluscs p fumatus and placamen placidium comparable extents of racemisation are evident in the fossil molluscs from the different cores providing a framework for a shelf wide regional aminostratigraphy fossil molluscs of the past three glacial maxima marine oxygen isotope stages ois 2 6 and 8 are identified within the vibracores based on amino acid racemisation evidence calibrated by radiocarbon dating of the same shell associations and correlation with independently dated deposits in southeastern australia the results extend the known geographical range of glacial age lowstand deposits on the mid and outer continental shelf of new south wales southeastern australia and help constrain the magnitude of sea level fall for the past three glaciations to at least 120 m below present sea level the extent of racemisation in specimens of p fumatus of marine ois 6 age with strongly indurated sediment encrustations adhering to the shell surfaces is significantly higher than for shells of equivalent age but without adhering sediment the higher extent of racemisation is consistent with a higher diagenetic temperature history for these specimens by implication these individual shells are likely to have remained within a relatively shallow water environment during the last glacial maximum resulting in the high degree of sediment induration and the higher extent of racemisation

increased seasonality in the western mediterranean during the last glacial from limpet shell geochemistry the seasonal cycle is a fundamental aspect of climate with a significant influence on mean climate and on human societies assessing seasonality in different climate states is therefore important but outside the tropics very few palaeoclimate records with seasonal resolution exist and there are currently no glacial age seasonal resolution sea surface temperature sst records at mid to high latitudes here we show that both mg ca and oxygen isotope 18o ratios in modern limpet patella shells record the seasonal range of sst in the western mediterranean a region particularly susceptible to seasonal change analysis of a suite of fossil limpet shells from gibraltar shows that sst seasonality was greater during the last glacial by 2 c as a result of greater winter cooling these extra tropical seasonal resolution sst records for the last glacial suggest that the presence of large ice sheets in the northern hemisphere enhances winter cooling this result also indicates that seasonality in the mediterranean is not well represented in most palaeoclimate models which typically show little change in seasonal amplitude and provides a new test for the accuracy of climate models

sea surface water temperatures over the period 1884 1983 reconstructed from oxygen isotope ratios of a bivalve mollusk shell arctica islandica southern north sea although climate system modeling cannot be imagined without long sea surface temperature sst records observational data is spatiotemporally incomplete and inhomogeneous prior to about 1950 moreover almost no high resolution sst proxies exist from temperate and boreal marine settings here we present a temporally equidistant high resolution sst proxy record of the southern north sea during the period 1884 1983 calculated from oxygen isotope ratios 18oaragonite of arctica islandica l a bivalve mollusk shell arctica islandica produces daily growth increments which enable precise intraannual dating the growing season of specimens from about 25 m water depth upper well mixed layer of the ocean started in february and ended in september observational coads etc and 18oaragonite derived sst data during february through september compare well to each other especially after 1950 apart from similar overall sst trends we found north atlantic oscillation type cycles of 7 9 years in our proxy sst record and in various different instrumentally determined sst chronologies no vital effects exist so that 18oaragonite ratios determined across the shell i e throughout lifetime of the studied specimen reflect ambient water temperatures that occurred during shell growth results of our study demonstrate that a islandica provides long independent and high resolution sst proxy chronologies from higher latitudes such records can complement and further validate observational sst data and help improving climate system models

assessment of mg ca in saccostrea glomerata the sydney rock oyster shell as a potential temperature record bivalve shell mg ca records can be important potential tracers of paleo temperature but evidence has shown that the temperature dependence of trace metal incorporation rates can vary significantly between different species and even within the same species this study assesses one such bivalve specimen as a potential temperature proxy for the east coast of australia specimens of the sydney rock oyster saccostrea glomerata were cultured for approximately one year at two locations on the east coast of australia moreton bay queensland a semi enclosed bay with consistently marine conditions and pambula lake new south wales a tidal lake which can undergo significant variations in salinity as a result of rainfall and river discharge transects of the oysters growth axis were analysed via la icp ms mg ca temperature relationships for the oysters show a robust temperature dependence but there is also a clear discrepancy between the two sites however this discrepancy was not evident when the temperature dependence of mg partition coefficients dmg was determined indicating that the difference seen in the direct mg cashell temperature relationships can be accounted for by variation in salinity at the estuarine site of pambula lake this has implications for the use of mg ca as a paleo temperature tracer within estuarine fauna as knowledge of the water chemistry is required to determine dmg values however s glomerata mg ca remains a promising paleo temperature tracer as the direct mg ca temperature relationships can still be applied to samples from environments that experienced little variation in salinity combined analysis of mg ca coupled with 18oshell records has the potential to enable the deconvolution of the combined salinity temperature signal in the 18oshell and mg cashell records

marine or estuarine radiocarbon reservoir corrections for mollusks a case study from a medieval site in the south of england abstract mollusk shells are frequently radiocarbon dated and provide reliable calibrated age ranges when the regional marine reservoir correction is well established for mollusks from an estuarine environment the reservoir correction may be significantly different than the regional marine reservoir correction due to the input of bedrock or soil derived carbonates some mollusk species such as oysters are tolerant of a significant range of salinities which makes it difficult to determine which reservoir correction is appropriate a case study is presented of an anomalous radiocarbon age for an oyster shell paint dish found in the fabric of the ruined nave walls of st mary s church shoreham by sea west sussex england stable isotopes 18 o and 13 c were used to establish the type of environment in which the oyster had lived paired marine and terrestrial samples from a nearby medieval site were radiocarbon dated to provide an appropriate reservoir correction

echinoderm skeletal preservation calcite aragonite seas and the mg ca ratio of phanerozoic oceans abstract the alternation between abiotic calcite and aragonite precipitation in shallow seawater and the oscillation of seawater mg ca ratio throughout the phanerozoic are both popular hypotheses echinoderms with well preserved stereom provide new empirical evidence that supports both these hypotheses analyses are reported from 29 specimens cambrian to eocene age containing ossicles preserved either as mg calcite 3 3 to 8 mole mgco3 or as mixed calcite and dolomite 5 to 12 5 mole mgco3 echinoderms with high mole mgco3 occur in the early cambrian and late carboniferous to triassic low values come from the silurian and jurassic to cretaceous the average composition of echinoderms with preserved stereom does not fall below 3 5 mol mgco3 during the phanerozoic and reaches its highest mean value of 16 0 mol mgco3 today an empirical partition coefficient of 0 03182 for modern tropical echinoids is used to indicate the mg ca ratio of ancient seawater from the mg ca ratio of fossil stereom some assumptions are involved and a likely error is calculated from the mg2 variation of modern echinoids high mean seawater mg ca ratios are calculated for early cambrian 3 3 and the late carboniferous to triassic 2 3 but never reached today s value of 5 2 low mg ca ratios 1 1 are indicated from jurassic to cretaceous echinoderms the 29 echinoderm samples plot close to first order mg ca seawater oscillations derived from geochemical models and mg ca ratios determined from fluid inclusions but considerable discrepancies exist when shorter 106 myr time intervals are considered further data and improved understanding of mg partitioning is required before accurate secular variation in the mg ca of seawater can be determined from echinoderms however they are an underused resource in this context and provide an excellent seawater archive

the prina complex in eastern crete and its relationship to possible miocene strike slip tectonics abstract the basal neogene formations in the ierapetra region eastern crete are strongly influenced by a late serravallian tectonic phase which resulted in the breakup of pre existing palaeogeographic patterns important vertical movements caused the southward emplacement of neogene sediments together with parts of the underlying pre neogene nappe pile the resulting chaotic association of exotic blocks and sediments known as the prina complex has the properties of a sedimentary melange it can be traced for more than 15 km from north to south in the north a relatively coherent accumulation of large slide masses overlies deformed neogene coarse clastics and pre neogene rocks distally it comprises a poorly stratified sequence of breccias and intermixed finer grained sediments which locally contains olistostromes and debris flows and interfingers to the south with submarine fan deposits the intricate relation of faulting and gravity sliding in a rapidly subsiding basin can be explained by generation in a strike slip setting it is suggested that the ierapetra basin and its offshore extension the south cretan trough were initiated by sinistral movements along a ne sw oriented fault zone implications of this model for the geodynamic evolution of the south aegean area are discussed

high resolution palaeoclimatology of the last millennium a review of current status and future prospects this review of late holocene palaeoclimatology represents the results from a pages clivar intersection panel meeting that took place in june 2006 the review is in three parts the principal high resolution proxy disciplines trees corals ice cores and documentary evidence emphasizing current issues in their use for climate reconstruction the various approaches that have been adopted to combine multiple climate proxy records to provide estimates of past annual to decadal timescale northern hemisphere surface temperatures and other climate variables such as large scale circulation indices and the forcing histories used in climate model simulations of the past millennium we discuss the need to develop a framework through which current and new approaches to interpreting these proxy data may be rigorously assessed using pseudo proxies derived from climate model runs where the answer is known the article concludes with a list of recommendations first more raw proxy data are required from the diverse disciplines and from more locations as well as replication for all proxy sources of the basic raw measurements to improve absolute dating and to better distinguish the proxy climate signal from noise second more effort is required to improve the understanding of what individual proxies respond to supported by more site measurements and process studies these activities should also be mindful of the correlation structure of instrumental data indicating which adjacent proxy records ought to be in agreement and which not third large scale climate reconstructions should be attempted using a wide variety of techniques emphasizing those for which quantified errors can be estimated at specified timescales fourth a greater use of climate model simulations is needed to guide the choice of reconstruction techniques the pseudo proxy concept and possibly help determine where given limited resources future sampling should be concentrated

effects of sample pretreatment and external contamination on bivalve shell and carrara marble δ 18 o and δ 13 c signatures abstract stable isotope signatures of bivalve shells serve as important paleoclimate proxies however such data can be biased as a consequence of physical and chemical sample pretreatment and contamination during sampling as yet the potential isotope error induced by paleontological preservation techniques and specific methods used in bivalve sclerochronology have not been systematically assessed to address these issues homogenized powder of a well preserved aragonitic fossil shell glycymeris obovata ca 30 ma old as well as carrara marble powder calcite were exposed to ultrasound a set of different staining solutions and cleaning agents in addition these reference materials were artificially contaminated with increasing proportions of powder prepared from periostracum alcian blue and cured adhesives whereas some treatments rinsing with milli q water immersion in alizarin red s solution and possibly mutvei s solution did not affect the isotope values of the carbonate samples severe isotope shifts were observed after immersing shell powder in feigl s solution 18 o 0 62 and mixing carrara marble powder with gluetec metal epoxy a contamination level of 41 7 wt shifted 18 o and 13 c values by 2 12 and 1 74 respectively increasing levels of metal epoxy in the sample resulted in a sharp non linear decrease of the isotope values the majority of tested treatments conducted with the carbonate powders and contaminants added to them caused minor to moderate mainly statistically significant isotope offsets bleaching with naocl and h 2 o 2 exposure to ethyl alcohol and rewoquat w 3690 pg a surfactant ultrasonic cleaning contamination with powder of alcian blue cured superglue several different polyepoxies methacrylates and polyvinyl butyral resins as well as periostracum in conclusion pretreatment of bivalve shells with an intended use for isotope analysis should be kept at an absolute minimum and contamination with adhesives etc should be avoided specimens from museum collections that underwent special conservation methods may be of limited value for isotope studies unless the history of sample treatment is known although only a few of the tested substances and methods strongly biased the isotope signatures even small changes can accumulate to levels that are inacceptable for high resolution paleoclimatology

biostratigraphic data from the cetmi melange northwest turkey palaeogeographic and tectonic implications abstract the cetmi accretionary melange is cropping out in the biga peninsula of northwest turkey it is characterised by an isolated position relatively far from the accretion complexes of the nearest suture zones which raises the question of its lateral correlations a detailed biostratigraphic investigation of the limestone and radiolarite blocks and the matrix of the cetmi melange allowed to propose a solution for this palaeogeographic problem scarce red nodular limestones in the han bulog facies represent the oldest lithology in the melange their late scythian ladinian age is based on chiosella gondolleloides the co occurrence of gladigondolella sp and nicoraella cf kockeli and paragondolella fuelopi light grey limestone blocks are a characteristic feature of the cetmi melange they occur in two distinct facies facies a consists of packstone to grainstone and is characterised by unsorted and poorly washed pelbiosparites facies b consists of wackestone to packstone and is characterised by poorly washed biopelmicrites to biopelsparites the foraminiferal assemblage of facies a containing triasina hantkeni is of late norian to rhaetian age the foraminiferal assemblage of facies b never contains t hantkeni and is characteristic of a late triassic carnian to norian rhaetian age radiolarian cherts are widely distributed in the cetmi melange they record fully pelagic sedimentation from the upper bajocian to the aptian the matrix of the cetmi melange consists of brown to black shales sometimes silty or siliceous intercalated with dark grey greywackes palynomorphs of one sample of brownish silty shale yielded an early to middle albian age based on the co occurrence of several dinoflagellate cysts the age of the matrix representing the youngest lithology within the melange and of the unconformable overlaying section latest albian cenomanian indicate that the melange forming process stopped between the early albian and the latest albian cenomanian at a regional scale the cetmi melange has little in common with the melanges from the izmir ankara and intra pontide sutures of northwestern turkey precluding a direct correlation on the other hand the cetmi melange shares several characteristics with the melange like units of the eastern rhodope zone bulgaria and greece like a major cenomanian transgression the reworking of triassic limestones and middle jurassic lower cretaceous radiolarians and the absence of jurassic cretaceous passive margin lithologies the occurrence of rhodopian units on the biga peninsula suggests that the studied units represent an isolated fragment of the rhodope zone in nw turkey

changing patterns of eastern mediterranean shellfish exploitation in the late glacial and early holocene oxygen isotope evidence from gastropod in epipaleolithic to neolithic human occupation layers at the haua fteah cave libya abstract the seasonal pattern of shellfish foraging at the archaeological site of haua fteah in the gebel akhdar libya was investigated from the epipaleolithic to the neolithic via oxygen isotope 18 o analyses of the topshell phorcus osilinus turbinatus to validate this species as faithful year round palaeoenvironmental recorder the intra annual variability of 18 o in modern shells and sea water was analysed and compared with measured sea surface temperature sst the shells were found to be good candidates for seasonal shellfish forging studies as they preserve nearly the complete annual sst cycle in their shell 18 o with minimal slowing or stoppage of growth during the terminal pleistocene early epipaleolithic locally known as the oranian with modeled dates of 17 2 12 5 ka at 2 probability douka et al 2014 analysis of archaeological specimens indicates that shellfish were foraged year round this complements other evidence from the archaeological record that shows that the cave was more intensively occupied in this period than before or afterwards this finding is significant as the period of the oranian was the coldest and driest phase of the last glacial cycle in the gebel akhdar adding weight to the theory that the gebel akhdar may have served as a refugium for humans in north africa during times of global climatic extremes mollusc exploitation in the latest pleistocene and early holocene during the late epipaleolithic locally known as the capsian c 12 7 to 9 ka and the neolithic c 8 5 to 5 4 ka occurred predominantly during winter other evidence from these archaeological phases shows that hunting activities occurred during the warmer months therefore the timing of holocene shellfish exploitation in the gebel akhdar may have been influenced by the seasonal availability of other resources at these times and possibly shellfish were used as a dietary supplement when other foods were less abundant

origin of the allochthons in the lycien belt southwest turkey abstract the lycien belt of southwest turkey lies between the menderes metamorphic massif to the northwest and the bey da lari carbonate platform to the southeast the belt is characterized by thrust faults melanges and peridotites stratigraphic and structural relationships suggest that the allochthons of the lycien belt were derived from two distinct tectonic terrains the koyce iz and elmali thrust slices were from south of the massif the tefenni nappe originated far north of the menderes massif the latter incorporates platform sediments melanges and ophiolites represent the edge of a continental platform opening into the tethys oceanic realm correlation of the elmali and koyce iz thrust slices and autochthonous tectonic elements shows that the lycien belt between the menderes massif and the bey da lari was a tectonically active zone of weakness the belt which may be at the extension of the ionian zone was subjected to repeated cycles of deep basin subsidence and intense deformation in triassic jurassic early cretaceous and tertiary times the tefenni nappe passed over the menderes massif and emplaced onto the lycien terrain in the late eocene the lycien terrain was subsequently fragmented and overthrusted southeastward onto the bey da lari shelf sediments in late miocene time

impact of atmospheric p co 2 seawater temperature and calcification rate on the δ 18 o and δ 13 c composition of echinoid calcite echinometra viridis the tropical echinoid echinometra viridis was reared in controlled laboratory experiments at temperatures of approximately 20 c and 30 c to mimic winter and summer temperatures and at carbon dioxide co2 partial pressures of approximately 487 ppm v and 805 ppm v to simulate current and predicted end of century levels spine material produced during the experimental period and dissolved inorganic carbon dic of the corresponding culture solutions were then analyzed for stable oxygen 18oe 18odic and carbon 13ce 13cdic isotopic composition fractionation of oxygen stable isotopes between the echinoid spines and dic of their corresponding culture solutions 18o 18oe 18odic was significantly inversely correlated with seawater temperature but not significantly correlated with atmospheric pco2 fractionation of carbon stable isotopes between the echinoid spines and dic of their corresponding culture solutions 13c 13ce 13cdic was significantly positively correlated with pco2 and significantly inversely correlated with temperature with pco2 functioning as the primary factor and temperature moderating the pco2 13c relationship echinoid calcification rate was significantly inversely correlated with both 18o and 13c across treatments with effects of pco2 and temperature controlled for through anova therefore calcification rate and potentially the rate of co occurring dissolution appear to be important drivers of the kinetic isotope effects observed in the echinoid spines study results suggest that echinoid 18o monitors seawater temperature but not atmospheric pco2 and that echinoid 13c monitors atmospheric pco2 with temperature moderating this relationship these findings coupled with echinoids long and generally high quality fossil record support prior assertions that fossil echinoid 18o is a viable archive of paleo seawater temperature throughout phanerozoic time and that 13c merits further investigation as a potential proxy of paleo atmospheric pco2 however the apparent impact of calcification rate on echinoid 18o and 13c suggests that paleoceanographic reconstructions derived from these proxies in fossil echinoids could be improved by incorporating the effects of growth rate

unraveling environmental histories from skeletal diaries advances in sclerochronology high resolution proxy archives from aquatic settings are essential to better understand processes and mechanisms of global change during the last decade it has become increasingly evident that calcified tissues of bivalve mollusks and cold water corals in particular can significantly increase our knowledge of seasonal to multi decadal paleoclimate and paleoenvironmental variability in the extratropical oceans and coastal marine settings daily tidal fortnightly and annual growth patterns of periodically formed skeletal hard parts provide a means to place the proxy record in a precise temporal context their extreme longevity coupled with the running similarity between growth increment time series of contemporaneous bivalves opens the possibility of constructing stacked chronologies covering centuries to millennia which provide information on decadal climate and environmental variability and magnitudes of climate variability through time a current major research focus is on how to translate geochemical properties of the skeletons into quantifiable environmental proxy data and how to eliminate the adverse influence of vital effects on the proxy records this special issue presents the most recent advances in the field of sclerochronology specifically calcified tissues of bivalve mollusks cold water corals and tropical shallow water corals the majority of the contributions deal with the potential reconstruction of temperature ph and productivity through the analysis of variable growth rates sr ca mg ca ba ca u ca li ca 13c 18o and 44 40ca four papers present composite chronologies of two long lived bivalve species and discuss inherent decadal climate variability and one study demonstrates that sclerochronology can shed light on socioeconomic patterns of past human populations as well as resource use and resource management by people

a late pleistocene refugium in mediterranean north africa palaeoenvironmental reconstruction from stable isotope analyses of land snail shells haua fteah libya abstract the late pleistocene to holocene archaeological record of north africa is key to understanding the emergence of anatomically modern humans into west asia and europe and the broadening of subsistence strategies in the shift from hunter gatherer to pastoral agricultural lifeways some contend that these developments were modulated by major shifts in climate and environment evaluation of this hypothesis requires the pairing of local and regional climate records with well dated archaeological sequences the haua fteah archaeological site in the gebel akhdar region of libya provides a key site to test this hypothesis as the cave contains one of the longest and most complete sequences of human occupation in north africa as well as abundant material for palaeoenvironmental reconstruction this study uses stable isotope analyses 18o and 13c of the terrestrial mollusc helix melanostoma to construct a palaeoenvironmental framework for interpreting north african human environment interactions from the upper palaeolithic to the neolithic 30 000 to 5000 years ago the land snail stable isotope records from haua fteah suggests that cool arid conditions in the cave peaked during marine isotope stage mis 2 this stage was however only marginally drier than previous and subsequent stages and coincided with an increase in occupation density in the cave this suggests that the gebel akhdar may have served as an environmental refugium from the more extreme aridity in the surrounding sahara and arid coastal plains for late stone age lsa populations in north africa conditions became progressively wetter towards the holocene however generally wetter conditions were interrupted by two arid episodes at c 8 0 ka and 7 3 ka that appear to coincide with regional changes reflected elsewhere in the mediterranean basin

the role of seasonality in abrupt climate change abstract a case is made that seasonality switches dominated by wintertime were instrumental in abrupt climate changes in the north atlantic region during the last glaciation and into the holocene the primary evidence comes from mismatches between mean annual temperatures from greenland ice cores in comparison with snowline changes in east greenland northern europe and north america the most likely explanation is a shutdown or reduction in strength of the conveyor this allows the spread of winter sea ice across the north atlantic thus causing the northern region to experience much colder winters because they mimic the greenland temperature rather than the snowline signal changes in the atlantic intertropical convergence zone and the asian monsoon may also share a winter linkage with greenland thus the paleoclimate record is consistent with the notion that a huge continental sector of the northern hemisphere stretching from greenland to asia was close to an extreme winter threshold during much of the last glaciation winter climate crossed this threshold repeatedly with marked changes in seasonality that may well have amplified and propagated a signal of abrupt change throughout the hemisphere and into the tropics

accurate increment identification and the spatial extent of the common signal in five arctica islandica chronologies from the fladen ground northern north sea 1 the creation of networks of shell based chronologies which can provide regionally extensive high resolution proxies for the marine environment depends on the spatial extent of the common environmental signal preserved in the shell banding and on the reliability of the dating model here arctica islandica chronologies from five neighboring sites in the north sea are compared and the strength of the common environmental signal across distances up to 80 km is analyzed using statistical techniques derived from dendrochronology the signal is found to be coherent across these distances in a linked study chronologies based on one of the same sites but constructed by two different research teams are compared methodological differences in increment interpretation are found to lead to slippage in the dating models systematic inclusion or exclusion of intermittently occurring increments results in the two chronologies becoming misaligned by 4 years over a 70 year period comparisons with neighboring chronologies indicate that such increments can generally be regarded as genuine annual increments even if they are not visible in all shells

changes of shell microstructural characteristics of cerastoderma edule bivalvia a novel proxy for water temperature abstract shells of bivalves potentially provide an excellent archive for high resolution paleoclimate studies however quantification of environmental variables specifically water temperature remains a very challenging task here we explore the possibility to infer water temperature from changes of microstructural characteristics of shells of the common cockle cerastoderma edule the size and elongation of individual microstructural units i e prisms in the outer shell layer of seven three to five year old specimens collected alive from the intertidal zone of the north sea near texel the netherlands and schillig germany were measured by means of automatic image processing growth patterns circatidal ciralunidian and fortnightly increments and lines shell oxygen isotope values and mark and recovery experiments were used to place the shell record in a precise temporal context irrespective of the locality and ontogenetic age size and elongation of the prisms increased non linearly with water temperature small 0 12 0 05 m 2 and round prisms elongation 2 42 0 31 were formed at temperatures of ca 10 c late april whereas larger 0 33 0 11 m 2 and more elongated prisms 3 26 0 28 occurred during hot summer ca 22 c no clear cut or consistent correlation existed between microstructural characteristics and growth rate as well as a variety of other environmental variables such as salinity chlorophyll a and turbidity based on these findings a model was constructed from three shells at texel that enables reconstruction of water temperature with a precision of 1 7 1 0 c from prism size and elongation sst 9 02 17 25 p s 1 10 p e this model was successfully tested at four shells from schillig the new temperature proxy can be of particular interest for paleoclimate studies in nearshore settings when non recrystallized c edule shells are available future studies are required to verify our findings and check if other species with the same and different microstructures show similar relationships with water temperature

oxygen isotope composition of modern and archaeological otoliths from the estuarine hardhead catfish ariopsis felis and their potential to record low latitude climate change abstract shells and otoliths fish ear bones from archaeological deposits of pine island southwest florida provide valuable archives of ecological patterns climate change and associated human responses many remains from these deposits that can be used for climate reconstruction are from estuarine animals the challenge in using oxygen isotope composition of their carbonate hard parts lies in deconvoluting the effects of temperature and salinity mixing of fresh and saltwater each having different isotopic compositions otoliths of the hardhead catfish ariopsis felis linneaus 1766 may provide a record of winter temperature without the complication of salinity variation because this fish spends winter months in waters of marine to near marine salinities hence 18 o water can be constrained when employing published temperature equations here we present geochemical data from modern and archaeological otoliths to evaluate whether they preserve winter temperature a modern catfish was caught near pine island sound and the otoliths lapilli removed archaeological otoliths from the 2nd 3rd century ad falling within the roman optimum ro and the 13th 14th century ad falling within the little ice age lia were obtained from the florida museum s collections oxygen isotope compositions were converted to temperature using published temperature equations and assuming 1 for gulf water isotopic compositions for the modern otolith range from 3 55 to 0 29 the lia otolith ranges from 3 92 to 0 52 and the ro otolith ranges from 1 80 to 0 84 all three otoliths record winter temperature 20 c similar to modern conditions calculated summer temperatures for the modern and lia otoliths 40 c are overestimated and reflect the combined influence of temperature and salinity when catfish inhabit brackish estuarine waters during their reproductive season in contrast summer temperature estimates for the ro otolith are similar to modern conditions indicating estuarine water during the summer was close to 1 this result suggests that seasonal rainfall patterns during the time period represented by the ro otolith were different than today such that the summer wet season was not prevalent

climatic records over the past 30 ka from temperate australia a synthesis from the oz intimate workgroup temperate australia sits between the heat engine of the tropics and the cold southern ocean encompassing a range of rainfall regimes and falling under the influence of different climatic drivers despite this heterogeneity broad scale trends in climatic and environmental change are evident over the past 30 ka during the early glacial period 30 22 ka and the last glacial maximum 22 18 ka climate was relatively cool across the entire temperate zone and there was an expansion of grasslands and increased fluvial activity in regionally important murray darling basin the temperate region at this time appears to be dominated by expanded sea ice in the southern ocean forcing a northerly shift in the position of the oceanic fronts and a concomitant influx of cold water along the southeast including tasmania and southwest australian coasts the deglacial period 18 12 ka was characterised by glacial recession and eventual disappearance resulting from an increase in temperature deduced from terrestrial records while there is some evidence for climatic reversals e g the antarctic cold reversal in high resolution marine sediment cores through this period the high spatial density of holocene terrestrial records reveals an overall expansion of sclerophyll woodland and rainforest taxa across the temperate region after 12 ka presumably in response to increasing temperature while hydrological records reveal spatially heterogeneous hydro climatic trends patterns after 6 ka suggest higher frequency climatic variability that possibly reflects the onset of large scale climate variability caused by the el nino southern oscillation

continuous marine radiocarbon reservoir calibration and the 13c suess effect in the irish sea results from the first multi centennial shell based marine master chronology abstract the identification in various proxy records of periods of rapid decadal scale climate change over recent millennia together with the possibility that feedback mechanisms may amplify climate system responses to increasing atmospheric co2 highlights the importance of a detailed understanding at high spatial and temporal resolutions of forcings and feedbacks within the system such an understanding has hitherto been limited because the temperate marine environment has lacked an absolute timescale of the kind provided by tree rings for the terrestrial environment and by corals for the tropical marine environment here we present the first annually resolved multi centennial 489 year absolutely dated shell based marine master chronology the chronology has been constructed by detrending and averaging annual growth increment widths in the shells of multiple specimens of the very long lived bivalve mollusc arctica islandica collected from sites to the south and west of the isle of man in the irish sea the strength of the common environmental signal expressed in the chronology is fully comparable with equivalent statistics for tree ring chronologies analysis of the 14c signal in the shells shows no trend in the marine radiocarbon reservoir correction r although it may be more variable before 1750 the 13c signal shows a very significant r2 0 456 p

reconstructing mid to high latitude marine climate and ocean variability using bivalves coralline algae and marine sediment cores from the northern hemisphere quantifying the role and contribution of the world s oceans in past present and future global change is an essential goal in climate paleoclimate and environmental studies although the global oceans interact and influence climate greatly the marine environment is substantially under represented in key climate assessment reports especially during the last millennium ipcc 2007 see palaeoclimate chapter 6 6 the last 2000 years the under representation of marine records in key climate documents likely results from the often imprecise chronologies associated with many marine based archives which greatly hinders singular climate comparisons lag lead phasing relationships with well dated and or annually resolved archives however several marine archive records have excellent chronological constraint in particular many marine bivalve taxa and coralline algae have annual increments that form within their carbonate framework that can be used to establish an absolutely dated chronology via cross dating techniques from the marine environment additionally in some cases where sedimentation rates are high and alternative chronological dating methods exist e g tephrochronology other than radiocarbon measurements often greater than 40 years uncertainty sediment archives can provide continuous sub decadal records of environmental change for centuries to millennia this brief introductory article and accompanying special issue will focus on the utilization of bivalves coralline algae and high resolution marine sediment cores in paleoclimate and environmental studies within the most recent millennium with a focus on the northern hemisphere

stone age midden deposition assessed by bivalve sclerochronology and radiocarbon wiggle matching of arctica islandica shell increments abstract sclerochronology the study of the skeletal diaries of mollusks and corals is a high resolution geochronological tool of versatile usage in archaeology and paleontology with increasingly growing opportunities much of the recent efforts have concentrated on building multi centennial bivalve growth records using annually deposited increments in the holocene shells comparable to tree ring chronologies in the context of geoarchaeology the hitherto unachieved potential includes the application of sclerochronology to reconstruct long term settlement histories here we contribute to both of these critical issues by presenting the first multi shell sclerochronology constrained by methods originally developed in tree ring research using anthropogenically deposited bivalve shells of arctica islandica excavated from a stone age midden in north norway our systematic chronological approach to shell growth histories lays the foundation for a multi dimensional dating framework that interacts between the incremental radioisotopic and stratigraphic evidence we show how the crossdating within and between the single shell records yields a 155 year multi shell sclerochronology supported by the 14 c ams dates that demonstrates minimum midden accumulation of 82 years and a depositional rate of 0 3 cm yr sclerochronology paves the way for radiocarbon wiggle matching which narrows the probabilistic 2 uncertainty range for the oldest and youngest 14 c ams dates to 3150 2980 and 3060 2890 bc respectively we attribute the spectral characteristics of the chronology primarily to the north atlantic oscillation suggesting essentially similar influences of climate variability on the stone age culture and our own society

coralline algae are global palaeothermometers with bi weekly resolution abstract high resolution palaeoclimate data are required for the holocene to resolve differences recorded by current proxies the pole to pole distribution of rhodoliths coralline algae with their annual and sub annual calcite bands make these attractive candidates for such a role these bands contain climate information in the form of elemental traces in situ temperature ist was recorded at two rhodolith beds for 1 5 years the concentrations of mgco 3 and srco 3 mol deposited in lithothamion glaciale and phymatolithon calcareum over this 18 month period were determined using electron and ion microprobes highly significant linear relationships exist between mg sr and ist as well as sea surface temperature calibration between mg concentration and ist was used to obtain a 2 year temperature profile from a subfossil rhodolith thallus indicating half the seasonal peak to peak temperature amplitude earlier during the holocene than the present day both slow growing species 1 allowed sampling resolutions of 23 year 1 which is equivalent to 1 reading every 2 weeks sub monthly mg and sr records in rhodoliths make them unique globally distributed palaeothermometers which may help refine regional climate histories during the holocene

complex evolution of the erzincan basin eastern turkey abstract two new tectonic models are presented to explain the pull apart opening of the erzincan basin our field studies indicated that the erzincan basin is not a typical rhombic pull apart basin instead it has a rather complex single or two stage pull apart opening mechanism the basin was initially formed as a result of a 4 km wide releasing stepover and a 15 divergence angle between segments 1 and 2 of the north anatolian fault zone nafz along which the westward tectonic escape of the anatolian block has been taking place the single stage model refers to the partitioning of the transtensional deformation by coeval normal and strike slip displacements on parallel trending faults which remained since their initiation the two stage model infers that the basin opening was modified later by the formation of the left lateral ovacik fault which caused fragmentation of the anatolian block the two stage pull apart basin opening mechanism accounts for the observed geometry of the erzincan basin the present day geometry of the basin indicates that there had been 35 5 km of right lateral displacement along the nafz and 5 2 km of left lateral displacement along the ovacik fault

new views of tropical paleoclimates from corals abstract corals offer a rich archive of past climate variability in tropical ocean regions where instrumental data are limited and where our knowledge of multi decadal climate sensitivity is incomplete in the eastern equatorial pacific coral isotopic records track variations in enso related changes in sea surface temperature further west corals record variability in sea surface temperature and rainfall that accompanies zonal displacement of the indonesian low during enso events these multi century records reveal previously unrecognised enso variability on time scales of decades to centuries outside the enso sensitive equatorial pacific long term trends towards recent warmer wetter conditions suggest the tropics respond to global forcings new coral paleothermometers indicate that surface ocean temperatures in the tropical southwestern pacific were depressed by 4 6 c during the younger dryas climatic event and rose episodically during the next 4000 yr high temporal resolution measurements of sr ca and 18 o in corals provide information about the surface ocean hydrologic balance and can resolve the seasonal balance between precipitation and evaporation radiocarbon measurements in corals coupled with ocean circulation models may be used to reconstruct near surface ocean circulation past mixing rates and the distribution of fossil fuel co2 in the upper ocean most recently seasonal to interannual variations in the radiocarbon of corals from the equatorial pacific have been linked to the redistribution of surface waters associated with the enso

late quaternary climatic variability in northern patagonia argentina based on δ18o of modern and fossil shells of amiantis purpurata bivalvia veneridae abstract amiantis purpurata is a common warm temperate water bivalve species distributed from southern brazil to northern patagonia argentina which has a rich and well preserved fossil record in the san matias gulf smg dating back to the late quaternary this study aims to establish a purpurata shells as a new palaeoarchive of past marine conditions in south america we compared the stable oxygen and carbon profiles 18oshell 13cshell of eleven specimens of a purpurata from different geological times modern late holocene and interglacial late pleistocene and additionally present in situ oxygen isotope values of seawater within smg 18owater using both sets of information we calculated and reconstructed palaeowater temperatures for the late holocene and compared them to modern water temperatures our findings indicate that a purpurata records past environmental parameters such as water temperatures on a seasonal scale and can therefore be considered a suitable candidate for future palaeoenvironmental reconstructions in northern patagonia this study is the first step towards further stable isotope analyses on fossil a purpurata shells which will show whether and if so to what extent important global climate events such as the neoglacial early holocene the hypsithermal middle holocene and the little ice age late holocene occurred in south america

oxygen isotopes from limpet shells implications for palaeothermometry and seasonal shellfish foraging studies in the mediterranean abstract limpet shells are common components of many archaeological sites in the mediterranean to test whether 18o values from archaeological patella caerulea shells can serve as a reliable palaeothermometer for the mediterranean and a reliable archive of season of collection information we collected live p caerulea from eight mediterranean locations in croatia israel libya malta tunisia and turkey shell growth patterns were studied in section and samples for oxygen isotope analysis were milled from the shells and used to calculate sea surface temperature sst as with other species of limpet sst reconstructed from p caerulea 18o values were lower than expected from observational records however when a correction factor of 0 72 was applied the shells recorded sst within the range of instrumental sst sst calculated from 18oshell values of the most recently formed shell portion of monthly collected shells from one site in libya were strongly and significantly correlated with instrumental sst in the region r2 0 95 oxygen isotope curves from individual shells sampled at high resolution from each of the study sites across the mediterranean exhibited sinusoidal patterns annual growth lines correlated with the lowest 18oshell values and were thus formed in summer however shell growth rates varied markedly between the sites some sites with larger shells recorded less than a year of growth in broad highly irregularly shaped increments at other sites medium sized shells recorded several years of growth with clear regular growth increments a sclerochronological approach can therefore be used to pre screen limpet shell sections before geochemical sampling the 18oshell values from shells sampled at high resolution recorded the full seasonal range of instrumental sst at each collection site this reinforces the potential of this species as one of the few sub seasonal resolution palaeoenvironmental archives in the region additionally the pattern of 18oshell variation from the last formed shell portion was studied to determine whether accurate season of collection information could be identified from p caerulea shells the correct season was interpreted 80 of the time indicating that this species is a good candidate for seasonal shellfish foraging studies using archaeological shells

the ksâr akil lebanon mollusc assemblage zooarchaeological and taphonomic investigations abstract shells of marine molluscs exploited by prehistoric humans constitute archives of palaeoecological and palaeoclimatic data as well as of human behaviour in coastal settings here we present our investigations on the mollusc assemblage from ks r akil lebanon a key site in southwestern asia occupied during the middle and upper palaeolithic the site plays an important role in understanding modern human dispersals into eurasia taxa from intertidal rocky shore subtidal soft bottom and rocky littoral habitats dominate the marine component of the invertebrate assemblage terrestrial snails indicate wooded and open half shaded habitats in the vicinity of the site species composition suggests that these habitats were present throughout the upper palaeolithic humans transported marine molluscs to the rockshelter as food packages for dietary purposes e g patella caerulea patella rustica phorcus turbinatus and shells of other taxa to be used as tools e g glycymeris sp or possibly for ornamental purposes e g nassarius gibbosulus and columbella rustica in the initial upper palaeolithic collection focussed on empty shells as raw material for utilitarian purposes in the subsequent early upper palaeolithic and later periods mollusc gathering was performed in an increasing number of habitats and shifted towards collection for human consumption which was the main reason for the introduction of shells to the site during the epipalaeolithic concurrent size shifts of live collected as well as beached specimens suggests that size changes were linked to environmental change rather than to potential overexploitation of dietary taxa by humans

a review of sea ice proxy information from polar ice cores sea ice plays an important role in earth s climate system the lack of direct indications of past sea ice coverage however means that there is limited knowledge of the sensitivity and rate at which sea ice dynamics are involved in amplifying climate changes as such there is a need to develop new proxy records for reconstructing past sea ice conditions here we review the advances that have been made in using chemical tracers preserved in ice cores to determine past changes in sea ice cover around antarctica ice core records of sea salt concentration show promise for revealing patterns of sea ice extent particularly over glacial interglacial time scales in the coldest climates however the sea salt signal appears to lose sensitivity and further work is required to determine how this proxy can be developed into a quantitative sea ice indicator methane sulphonic acid msa in near coastal ice cores has been used to reconstruct quantified changes and interannual variability in sea ice extent over shorter time scales spanning the last 160 years and has potential to be extended to produce records of antarctic sea ice changes throughout the holocene however the msa ice core proxy also requires careful site assessment and interpretation alongside other palaeoclimate indicators to ensure reconstructions are not biased by non sea ice factors and we summarise some recommended strategies for the further development of sea ice histories from ice core msa for both proxies the limited information about the production and transfer of chemical markers from the sea ice zone to the antarctic ice sheets remains an issue that requires further multidisciplinary study despite some exploratory and statistical work the application of either proxy as an indicator of sea ice change in the arctic also remains largely unknown as information about these new ice core proxies builds so too does the potential to develop a more comprehensive understanding of past changes in sea ice and its role in both long and short term climate changes

stable isotope fractionation between mollusc shells and marine waters from martinique island abstract forty nine aragonitic and calcitic shells from 14 species of marine tropical molluscs bivalvia gastropoda polyplacophora and ambient waters from martinique have been analyzed for their carbon and oxygen isotope compositions mineralogy of shells was systematically determined by raman spectroscopy that reveals composite shell structures and early processes of diagenetic alteration in mangrove brackish waters result from the mixing between 89 1 of seawater and 11 1 of freshwater a hydrological budget quantified by both oxygen isotope and salinity mass balance calculations mollusc shells from the mangrove environment s 31 18 o 0 5 are characterized by mean 13 c values 1 2 lower than those 2 6 living in the open sea s 35 18 o 1 these low carbon isotope compositions result from the oxidation of organic matter into bicarbonate ions used in the building of mollusc shells the oxygen isotope compositions of the studied mollusc species are mainly controlled by the temperature and composition of seawater whereas the role of the so called vital effects is negligible contrasting with carbon isotopes variability in the 18 o values among and within species of mollusc shells is very low 1 0 15 for a given littoral environment using ambient temperatures of seawater 28 30 c oxygen isotope fractionations between all studied living species and environmental waters match those extrapolated from the fractionation equation established for molluscs by grossman and ku chem geol isot geosci sect 59 1986 59 in the range 3 20 c by analyzing calcite and aragonite layers from the same shell or by comparing shells from different species living in the same environment there is no evidence that oxygen isotope fractionation between aragonite and water differs from that between calcite and water on the basis of these results we conclude that the oxygen isotope compositions of shells from most fossil mollusc species are suitable to estimate past seawater temperatures at any paleolatitude

seasonal climate signals 1990 2008 in a modern soreq cave stalagmite as revealed by high resolution geochemical analysis article high resolution isotopic and geochemical analyses in a modern 1990 2008 soreq cave stalagmite are com pared to instrumental records of rainfall and dripwater from the cave with the aim of determining how seasonal resolutionclimateinformationistransmittedtospeleothemgeochemistry insitu micron scaleanalysis of oxygen isotope ratios 18 o and trace elements by ion microprobe in combination with a continuous linear traverse of trace element concentrations by laser ablation icp ms la icp ms allow the definition of geochem ical pathways within the cave fluorescent banding imaged by confocal laser fluorescent microscopy clfm as well as

multi proxy reconstructions of northeastern pacific sea surface temperature data from trees and pacific geoduck abstract we demonstrate the potential for developing sea surface temperature sst reconstructions in the northeast pacific from combinations of tree ring and growth increment chronologies of the long lived marine bivalve the pacific geoduck six pacific geoduck chronologies developed from site along the washington british columbia coast are compared and combined with tree ring chronologies from california to alaska all chronologies are annually resolved and strongly relate to local to regional scale sst though differences in the response season as well as the spectral properties of the two proxies are observed both proxy types closely track sst and when used in combination yield a more robust sst reconstruction than tree ring or geoduck chronologies could provide alone in total variance explained in sst is 63 9 at the regional scale and 68 2 at a local scale providing sst estimates for more than 60 years prior to the start of continuous instrumental records in this region this study represents one of the few climate reconstructions where both proxies are annually resolved and is the first to integrate regional networks of geoduck chronologies and tree ring chronologies

high resolution records of growth temperature and life history of two nacella limpet species tierra del fuego argentina abstract stable isotope ratios in patelloid limpets of the genus patella have been established as proxies for coastal environmental change at sub monthly resolution along the eastern north atlantic and mediterranean sea nacella deaurata gmelin 1791 and n magellanica gmelin 1791 are common intertidal species of patelloid limpets inhabiting the coast of tierra del fuego argentina chile and are commonly found in holocene archaeological deposits here we examine oxygen and carbon isotope ratios 18oshell and 13cshell respectively of modern specimens of n deaurata and n magellanica to test the hypotheses that 1 they form their shells in isotopic equilibrium with ambient water and 2 prominent growth lines form annually based on growth margin analysis of 18oshell values we identified a positive offset of 1 3 0 4 n deaurata and 1 3 0 3 n magellanica from expected equilibrium similar to other patelloid limpets because the offset is relatively consistent between observed and expected values it can be taken into account to reliably reconstruct growth temperature seawater temperature estimated from oxygen isotope time series data falls within the observed range thus n deaurata and n magellenica shells serve as reliable proxy archives of seasonal variation in coastal seawater temperature time series of 13cshell values do not vary seasonally in all shells hence the influence on its variation requires further study the timing of prominent growth lines contextualized by the 18oshell time series form twice a year and therefore cannot be used to estimate lifespan future isotopic analysis of archaeological nacella shells can potentially provide much needed information about holocene climate change at sub monthly resolution from high latitude south american locations and contribute to our understanding of human behavior and human climate interactions

shell midden sclerochronology abstract sclerochronological analysis of shell midden faunal remains offers a unique opportunity to study climate and environmental change in relation to human activity middens exist near most aquatic habitats almost worldwide for much of the late pleistocene and holocene they afford good preservation of accretionary calcium carbonate remains such as mollusk shells and fish otoliths in comparatively well dated contexts as such midden samples are a source of sequential proxy records of past climate and environmental conditions and may provide detailed pictures of human environment interaction however midden samples present several challenges to the development and application of sclerochronological proxies including unique taphonomic concerns here these challenges are outlined within descriptions of the major applications of midden sclerochronology archeological concerns including season of capture reconstructing the history of anthropogenic environmental impacts and paleoclimate environment proxy reconstructions

north atlantic oscillation dynamics recorded in shells of a long lived bivalve mollusk existing reconstructions of the winter north atlantic oscillation wnao are based on terrestrial proxies and historical documents no direct high resolution long term rec ords from marine settings are available for this major climate dictating phenomenon which severely affects a variety of economic aspects of our society here we present a 245 yr proxy wnao index based on shells of the long lived marine bivalve mollusk arctica islandica variations in annual rates of shell growth are positively correlated with wnao related changes in the food supply maximum amplitudes in frequency bands of 7 9 and 5 7 yr fall exactly within the range of instrumental and other proxy wnao indices these estimates were obtained for specimens collected live 2000 km apart in the central north sea and on the norwegian shelf hence the wnao influences hydrographic regimes of large regions of the ocean our study demonstrates that a islandica can reliably reconstruct wnao dynamics for time intervals and regions without instrumental records our new tool functions as a proxy for the wnao index prior to the twentieth century greenhouse forcing and has the potential to further validate other proxy based wnao records

an explanation of the effect of seawater carbonate concentration on foraminiferal oxygen isotopes abstract stable oxygen isotope ratios of foraminiferal calcite are widely used in paleoceanography to provide a chronology of temperature changes during ocean history it was recently demonstrated that the stable oxygen isotope ratios in planktonic foraminifera are affected by changes of the seawater chemistry carbonate system the 18 o of the foraminiferal calcite decreases with increasing co 3 2 concentration or p h this paper provides a simple explanation for seawater chemistry dependent stable oxygen isotope variations in the planktonic foraminifera orbulina universa which is derived from oxygen isotope partitioning during inorganic precipitation the oxygen isotope fractionation between water and the dissolved carbonate species s h 2 co 3 hco 3 co 3 2 decreases with increasing p h provided that calcium carbonate is formed from a mixture of the carbonate species in proportion to their relative contribution to s the oxygen isotopic composition of caco 3 also decreases with increasing p h the slope of shell 18 o vs co 3 2 of orbulina universa observed in culture experiments is 0 0022 mol kg 1 1 spero et al 1997 whereas the slope derived from inorganic precipitation is 0 0024 mol kg 1 the theory also provides an explanation of the nonequilibrium fractionation effects in synthetic carbonates described by kim and o neil 1997 which can be understood in terms of equilibrium fractionation at different p h the results presented here emphasize that the oxygen isotope fractionation between calcium carbonate and water does not only depend on the temperature but also on the p h of the solution from which it is formed