multi taxa isotopic investigation of paleohydrology in the lower cretaceous cedar mountain formation eastern utah u s a deciphering effects of the nevadaplano plateau on regional climate we investigate the regional climatic effects of the formation of the nevadaplano plateau during the sevier orogeny in an overall warming world paleohydrology was reconstructed from 590 individual measurements of phosphate o isotopes in continental faunas of the lower cretaceous cedar mountain formation utah u s a semi aquatic turtles crocodiles and terrestrial dinosaurs taxa are compared to coeval pedogenic carbonates to interpret changing water sources over time samples were grouped into four stratigraphic faunas lower yellow cat upper yellow cat ruby ranch and mussentuchit members resulting isotopic values were converted to d18 ow values using established d 18 op d 18 ow and d 18 oc d 18 ow relationships at a formation scale turtles d 18 op 14 1 to 15 7 v smow and crocodiles d 18 op 15 0 to 19 2 document water compositions of 28 1 to 26 1 and 27 7 to 24 2 respectively within the zonal range for formation scale meteoric water at 34u n paleolatitude 27 1 to 24 8 established by pedogenic carbonates d18 oc 22 0 to 23 5 v smow these data suggest that like soil carbonates turtle and crocodile phosphate isotopes can be used as proxies for meteoric water isotopic composition dinosaurd18 op sauropods 19 7 to 21 9 ornithischians 16 6to 21 7 small theropods 16 9to 18 2 andlarge allosauroids 19 1 to 20 3 values generally exceed those of semi aquatic taxa using mass balance equations for modern terrestrial animals adjusted for size and inferred dinosaur physiology ingested water is calculated for the above dinosaur groups on a member scale when meteoric water values are compared with calculated dinosaur drinking water values are equal to or lighter than meteoric water for most herbivorous groups as low as 215 5 for ornithischians and equal to or heavier than meteoric water for most carnivorous groups as high as 22 0 for allosauroids changes in d18 ometeoric water d 18 odinosaur ingested water faunal assemblages and sedimentology from member to member correlate to thrusting events of the sevier orogeny high elevations in the orogeny attenuated the influences of pacific moisture causing rainshadow induced aridity on the leeward foreland basin during upper yellow cat time and hosted seasonal snow accumulation by the end of ruby ranch time as suggested by 18 o enriched water e g up to an average of 22 0 from an allosauroid tooth and extremely 18 o depleted water e g 215 5 for ornithischians in the ruby ranch member by mussentuchit time delivery of the western interior seaway dominated moisture to the region despite continued rise of the sevier mountains

trace and rare earth element compositions of silurian conodonts from the vesiku bone bed histological and palaeoenvironmental implications abstract in situ minor trace and rare earth element ree compositions have been measured in conodonts from the lower silurian vesiku bone bed estonia with the aim to visualize and to quantify conodont apatite elemental geochemistry to evaluate compositional differences between conodont histologies and to evaluate the use of conodont chemistry as a palaeobiological or palaeoenvironmental proxy tissue selective analyses of minor trace and rare earth element compositions of albid hyaline and basal tissues demonstrated significant chemical offsets among these histologies the albid tissue had the lowest ree and trace element concentrations suggesting crystallinity determined better resilience to diagenetic alteration as documented in previous studies conversely the basal tissue had highest concentrations of rees and many trace elements except for sr that showed an opposite trend the higher concentrations in albid and hyaline tissues supports the in vivo sr incorporation by conodont crown nonetheless the obtained sn normalized ree patterns were uniform through all the analyzed conodont taxa and different tissues implying common diagenetic history absence of a ce anomaly and defined negative eu anomaly indicate reducing conditions during early burial these results validate current interpretations of the palaeoenvironmental conditions during the deposition of vesiku bone bed and bolsters the use of rees in palaeozoic marine vertebrates as an important palaeoenvironmental proxy

use of multiple oxygen isotope proxies for elucidating arctic cretaceous palaeo hydrology stable oxygen isotope analysis of siderite and dinosaur tooth enamel phosphate from the campanian maastrichtian prince creek formation alaska usa are analysed to determine the palaeohydrology of the ancient colville basin north of the ancestral brooks range do of freshwater siderites relative to v pdb ranges between 214 86 and 216 21 dinosaur tooth enamel do from three different sites kikak tegoseak pediomys point liscomb range between 3 9 and 10 2 0 dometeoric water are calculated from dosiderite that formed at seasonal temperatures ranging from 22 to 14 5 8c with a mean annual temperature of 6 3 8c at 6 3 8c the dow calculated from siderite ranged between 222 23 and 220 89 v smow ingested water compositions are estimated from dinosaur teeth assuming body temperatures of 37 8c and local relative humidity of 77 5 resulting in values ranging from 228 7 to 220 4 v smow suggesting consumption of meteoric water and orographically depleted runoff from the brooks range the ranges in calculated dometeoric water are compatible between the two proxies and are mutually corroborating evidence of extremely o depleted precipitation at high latitudes during the late cretaceous relative to those generated using general circulation models this depletion is proposed to result from increased rainout effects from an intensified hydrological cycle which probably played a role in sustaining polar warmth supplementary material parameters used for generation of equations compared to kohn 1996 can be found at http www geolsoc org uk sup18642 stable isotopic proxies are invaluable tools for understanding past and current climates pedogenic carbonates siderite and calcite are commonly used to determine the isotopic composition of meteoric water lohmann 1988 hays grossman 1991 ludvigson et al 1998 ufnar et al 2004a suarez et al 2011 when analysed over a range of latitudes the resulting isotopic gradients can be used to determine global isotopic groundwater gradients this gradient is related to the isotopic composition of the precipitation which is itself related to temperature gradients humidity and in some instances orographic effects isotopic studies of the cretaceous are of particular importance because future climatic conditions kiehl 2011 are predicted to approach those pco2 temperature seen in the various greenhouse worlds of the cretaceous several studies on the cretaceous climate have revealed shallow equatorial topole air and ocean temperature gradients wolfe upchurch 1987 amiot et al 2004 jenkyns et al 2004 puceat et al 2007 while others have indicated equator to pole precipitation do gradients that are steeper than the modern climate system ludvigson et al 1998 ufnar et al 2002 suarez et al 2011 this steep gradient has been explained as resulting from increased rainout thereby increasing latent heat transport from the equator to the poles during greenhouse conditions ufnar et al 2004b these conclusions are based on empirical from bojar a v melinte dobrinescu m c smit j eds isotopic studies in cretaceous research geological society london special publications 382 http dx doi org 10 1144 sp382 3 the geological society of london 2013 publishing disclaimer www geolsoc org uk pub ethics by guest on june 17 2013 http sp lyellcollection org downloaded from

earthquakes of the holocene geologic studies of earthquakes involve mapping of coseismic surface faulting and secondary deformation from historical events trenching and geomorphic analysis to define the timing and size of past earthquakes and investigations of fault zone structure and geometry in both unconsolidated sediments and bedrock this research is now being referred to as paleoseismology seismic geology and earthquake geology since the mid 1970s it has led to some of the most exciting and important contributions to the understanding of earthquake behavior in space and time hanks 1985 allen 1986 the present report is the first of what is hoped will become a regularly contributed summary of the geologic aspects of the study of earthquakes

latitudinal temperature gradient during the cretaceous upper campanian middle maastrichtian y18o record of continental vertebrates latitudinal variations in model biogenic apatite d18o values were calculated using fractionation equations of vertebrates and weighted rainfall y18o values along with mean annual air temperatures provided by iaea wmo meteorological stations the reference equation obtained was used to compute a continental temperature gradient for the late campanian middle maastrichtian interval by using published and new d18o values of phosphate from vertebrates samples are mainly tooth enamel from crocodilians and dinosaurs that lived at paleolatitudes ranging from 83 4 n alaska to 32 3 s madagascar the temperature gradient was less steep 0 4 0 1 c latitude than the present day one 0 6 c latitude with temperatures that decreased from about 30 c near the equator to about 5 c at the poles above 30 of paleolatitude air temperatures were higher than at present the validity of these results is discussed by comparison with climatic criteria inferred from paleontological paleobotanical and sedimentological data the latitudinal distribution of oxygen isotope compositions of continental vertebrates is potentially a powerful tool for quantifying mesozoic terrestrial climates

apatite for destruction isotopic and geochemical analyses of bioapatites and sediments from the upper devonian escuminac formation miguasha quebec abstract the paleoenvironmental context and diagenetic history of the middle frasnian escuminac formation were investigated through geochemical rare earth elements and isotopic rb sr nd sm analyses of fossil fish material and sediments samples of sediments and bioapatite were collected from the base to the top of the escuminac formation strontium isotope ratios 87 sr 86 sr for bioapatites vary from 0 70804 to 0 70845 and overlap with frasnian seawater sr isotope compositions though most of the biogenic apatites analyzed show a variable drift from marine values toward a more radiogenic continental signature this trend is possibly the result of post mortem sr exchange between fossils and a fluid isotopically distinct from the waters in which they developed all bioapatites are heavily enriched in rare earth elements ree and display a shale normalized pattern that shows heavy ree hree depletion and a slight middle ree mree enrichment the e nd t values of the sediments range from 4 8 to 6 4 and are consistent with a sedimentary provenance derived from an appalachian source for the escuminac formation in contrast more radiogenic e nd t values ranging from 2 6 to 4 6 were obtained for the bioapatites the discrepancy between sediments and fossil material e nd t implies the presence of a second diagenetic nd reservoir for the escuminac bioapatites we propose that this reservoir reflects in part seawater the similarity between the nd isotope compositions of the escuminac fossils and late devonian conodonts from poland argues for a close connection between waters of the devonian rheic ocean and the escuminac formation collector basin

water utilization of the cretaceous mussentuchit member local vertebrate fauna cedar mountain formation utah usa using oxygen isotopic composition of phosphate abstract while the oxygen isotopic composition of pedogenic carbonate has successfully been used to address the effects of global climate change on the hydrologic cycle detailed regional paleohydrologic studies are lacking since the hydrologic cycle can vary extensively on local or regional scales due to events such as such as mountain building and since pedogenic carbonates calcite form in a narrow moisture regime other proxies such as vertebrate remains must be used to decipher local versus regional variations in paleohydrology in this study the oxygen isotopic composition 18op of phosphatic remains from a diverse set of vertebrate fossils fish turtles crocodiles dinosaurs and micro mammals from the mussentuchit member mm of the cedar mountain formation utah usa aptian to cenomanian are analyzed in order to determine differences among the available water reservoirs and water utilization of each taxon calculated changes in water reservoir 18ow over time are then used to determine the effects of the incursion of the western interior seaway wis and the sevier mountains on paleohydrology during the mm time calculation of 18ow from the results of isotopic analysis of phosphate oxygen suggests that turtles and crocodiles serve as another proxy for meteoric water 18o that can be used as a measure of average local precipitation 18ow similar to pedogenic calcite pedogenic calcites can be slightly biased toward higher values however due to their formation during evaporative conditions turtles and crocodiles can be used in place of pedogenic calcite in environments that are not conducive to pedogenic carbonate formation remains of fish with rounded tooth morphology have 18op values that predict temperatures consistent with other estimates of mean annual temperature for this latitude and time the 18op of ganoid scales and teeth with pointed morphology however indicates that these skeletal materials were precipitated from water that is 18o enriched due to migration to either evaporatively enriched water or 18o enriched estuarine waters of the western interior seaway wis another possibility that cannot be discounted and assuming all morphological remains are from the same taxon is that the pointed teeth and ganoid scales precipitated at different temperatures than rounded teeth mammal and herbivorous dinosaur 18op suggests they primarily drank isotopically depleted river water co existence of crocodiles turtles and mammals allows for calculation of relative humidity from site to site and these calculations suggest humidity averaged 58 and ranged between 42 and 76 the 18ow values estimated from semi aquatic taxa and pedogenic calcite suggest dominance of wis derived moisture during their growth herbivorous dinosaurs particularly indicate that altitude and catchment effects from the sevier mountains are seemingly important for river water 18ow in the fall through early spring these data suggest that temporal changes in the isotopic composition of the mm fauna are produced by the small scale regressive transgressive cycles of the wis

a multi proxy geochemical investigation of the early paleocene danian continental palaeoclimate at the fontllonga 3 site south central pyrenees spain chronologically well constrained non marine deposits across the cretaceous tertiary boundary ktb are exceptionally rare the fontllonga section tremp formation south central pyrenees lleida spain constitutes one of these rare global records stable isotope 18oco3 and 13c analyses have been performed on the carbonate fraction of 29 samples from diverse skeletal micro remains charophyte gyrogonites gastropod shells ostracod valves and isolated skeletal remains of lepisosteids and pycnodonts from the earliest danian site fontllonga 3 a mean ba ca water palaeotemperature of 28 0 6 7 c has been obtained from the ganoine of 25 lepisosteid scales this mean palaeotemperature is comparable with the temperature tolerance range for extant relatives of fossil osteoglossiform fish found at fontllonga 3 which require a temperature range of 24 35 c mean annual temperature 27 30 c to survive using the temperature range provided by the ba ca palaeothermometer 21 3 34 7 c it is possible to determine 18owater values from the isotopic content of charophyte gyrogonites gastropod shells ostracod valves and fish remains mean 18oco3 5 00 0 21 18owater values of between 4 01 and 0 95 vsmow are calculated which when combined with la yb n versus la sm n plots are in good agreement with the sedimentary interpretation of the site as an estuarine environment based upon a comparison with modern day meteorical conditions these isotopic values are relatively high for subtropical freshwaters suggesting a low precipitation rate amount effect high evaporation rate and or long residence time when combined with other isotopic palaeobotanical and mineralogical studies carried out in the pyrenean and tethys realms this first geochemical study of an early paleocene site is consistent with there being a subtropical seasonally dry climate in the south central pyrenees at this time

diagenesis of phosphatic hardgrounds in the monterey formation a perspective from bulk and clumped isotope geochemistry understanding the authigenesis of carbon ate fluorapatite through isotopic geochem istry can yield important information on fundamental geologic processes occurring on continental margins around the world this is particularly true for phosphatic hardgrounds which are often found in regions of upwell ing but of which questions remain about the initial formation and subsequent diagen esis here we apply standard isotopes 13 c 18 o alongside the novel clumped isotope 47 used in this study for the first time to reconstruct the temperature of formation of carbonate ions within the lattice of sedimen tary carbonate fluorapatite we investigated phosphatic hardgrounds of miocene age 12 7 10 8 ma sampled at el capitan state beach in the monterey formation the range of isotopic signatures observed is between 1 5 and 8 0 for 13 c relative to the vienna peedee belemnite vpdb standard and 9 5 and 6 0 vpdb for 18 o and val ues range between 0 599 and 0 615 for 47 the enriched 13 c and depleted 18 o signa tures are suggestive of recrystallization within the methanogenic zone clumped isotope geo chemistry further constrains this transforma tion as having taken place at a temperature of 61 66 c 5 c in line with previous esti mates for maximum burial of the monterey formation based on the silica phase transi tion the calculated 18 o for the connate fluid shows an expected range for seawater composition for the miocene suggesting only minor contribution of silica derived oxygen to the 18 o of carbonate fluorapatite the combined conventional and clumped isotope data set also points out that methanogenesis took place deeper within the sediment in the middle miocene than at present day within the santa barbara basin this study fur thers our understanding of phosphogenesis and potential links to burial processes in the monterey formation and it shows for the first time that the clumped isotope paleother mometer could be used to under stand funda mental geochemical processes in authigenic sedimentary phosphates

oxygen isotope variations in phosphate of biogenic apatites ii phosphorite rocks abstract phosphorites from sedimentary sequences ranging in age from archaean to recent were analysed for 18 o in both the po 4 18 o p and co 3 18 o c in the apatite lattice the oxygen isotope record is considerably better preserved in phosphates than in either carbonates or cherts the use of the longinelli and nuti 8 temperature equation yields temperatures for recent phosphorites that are in good agreement with those measured in the field the 18 o p values of ancient phosphorites decrease with increasing age these changes with time are not likely to be due to post depositional exchange changes in 18 o values of seawater and variations of temperature with time can account for the 18 o p time trend but the latter explanation is preferred in ancient phosphorites 18 o c in structurally bound carbonate in apatite is not a reliable geochemical indicator

nd and sr isotope compositions in modern and fossil bones proxies for vertebrate provenance and taphonomy abstract rare earth elements ree while not essential for the physiologic functions of animals are ingested and incorporated in ppb concentrations in bones and teeth nd isotope compositions of modern bones of animals from isotopically distinct habitats demonstrate that the 143 nd 144 nd of the apatite can be used as a fingerprint for bedrock geology or ambient water mass this potentially allows the provenance and migration of extant vertebrates to be traced similar to the use of sr isotopes although ree may be enriched by up to 5 orders of magnitude during diagenesis and recrystallization of bone apatite in vivo 143 nd 144 nd may be preserved in the inner cortex of fossil bones or enamel however tracking the provenance of ancient or extinct vertebrates is possible only for well preserved archeological and paleontological skeletal remains with in vivo like nd contents at the ppb level intra bone and tooth ree analysis can be used to screen for appropriate areas large intra bone nd concentration gradients of 10 1 10 3 are often measured nd concentrations in the inner bone cortex increase over timescales of millions of years while bone rims may be enriched over millenial timescales nevertheless e nd values are often similar within one e nd unit within a single bone larger intra bone differences in specimens may either reflect a partial preservation of in vivo values or changing e nd values of the diagenetic fluid during fossilization however most fossil specimens and the outer rims of bones will record taphonomic 143 nd 144 nd incorporated post mortem during diagenesis unlike ree patterns 143 nd 144 nd are not biased by fractionation processes during ree uptake into the apatite crystal lattice hence the e nd value is an important tracer for taphonomy and reworking bones and teeth from autochthonous fossil assemblages have small variations of 1 e nd unit only in contrast fossil bones and teeth from over 20 different marine and terrestrial fossil sites have a total range of e nd values from 13 0 to 4 9 n 80 often matching the composition of the embedding sediment this implies that the surrounding sediment is the source of nd in the fossil bones and that the specimens of this study seem not to have been reworked differences in e nd values between skeletal remains and embedding sediment may either indicate reworking of fossils and or a ree uptake from a diagenetic fluid with non sediment derived e nd values the latter often applies to fossil shark teeth which may preserve paleo seawater values complementary to e nd values 87 sr 86 sr can help to further constrain the fossil provenance and reworking

isotope compositions c o sr nd of vertebrate fossils from the middle eocene oil shale of messel germany implications for their taphonomy and palaeoenvironment abstract the middle eocene oil shale deposits of messel are famous for their exceptionally well preserved articulated 47 myr old vertebrate fossils that often still display soft tissue preservation the isotopic compositions o c sr nd were analysed from skeletal remains of messel s terrestrial and aquatic vertebrates to determine the condition of geochemical preservation authigenic phosphate minerals and siderite were also analysed to characterise the isotope compositions of diagenetic phases in messel diagenetic end member values of the volcanically influenced and due to methanogenesis 12 c depleted anoxic bottom water of the meromictic eocene maar lake are isotopically very distinct from in vivo bioapatite values of terrestrial vertebrates this unique taphonomic setting allows the assessment of the geochemical preservation of the vertebrate fossils a combined multi isotope approach demonstrates that enamel of fossil vertebrates from messel is geochemically exceptionally well preserved and still contains near in vivo c o sr and possibly even nd isotope compositions while bone and dentine are diagenetically altered enamel of the hippomorph perissodactyl propalaeotherium has low 13 c values 9 0 7 typical for c 3 plant feeders dentine of the same teeth has 13 c values 15 17 higher amongst the highest 13 c bioapatite values reported for terrestrial vertebrates this reflects diagenetic carbonate exchange with the strongly 12 c depleted anoxic lake bottom water enamel 87 sr 86 sr values 0 711 0 001 are consistent with propalaeotherium feeding on palaeozoic bedrocks surrounding lake messel and suggests that the basaltic tuff ring around the maar was already eroded 640 ka after its formation dentine has however much lower volcanically influenced 87 sr 86 sr 0 706 due to diagenetic sr uptake from the lake water oil shale enamel 18 o p values 18 0 6 of propalaeotherium are 2 3 lower than those of bones and scales of aquatic vertebrates that lived in the 18 o enriched lake water using transfer functions a 18 o h 2 o value of 5 1 for meteoric water and a mat of 18 2 5 c were reconstructed for messel

diet preferences and climate inferred from oxygen and carbon isotopes of tooth enamel of tarbosaurus bataar nemegt formation upper cretaceous mongolia abstract stable isotopes of oxygen and carbon of tooth enamel are increasingly being used as tracers to study palaeoecology and the diet preferences of fossil vertebrates we serially sampled tooth enamel carbonate along the growth axes of five early maastrichtian carnivorous dinosaur teeth tarbosaurus bataar tyrannosaurid from the nemegt formation mongolia in order to identify seasonal climatic variations and determine the diet of this apex predator additional bulk samples of dentine bone and surrounding sediment were analyzed in order to exclude diagenetic obfuscation of the isotopic record enamel samples of potential prey species for dietary studies were also analyzed in the case of the largest specimens the sampled teeth usually recorded annual cycles ranging between two thirds and a full year fluctuations in 18o values in tyrannosaurid teeth suggest seasonality high annual temperatures with distinct precipitation humidity maxima during summer months with mean annual temperatures mat ten degrees higher than those of present day mongolia the seasonal pattern of 18o shows similarities to that of the modern day shijiazhuang global network of isotopes in precipitation station northern china and suggests that the nemegt biota flourished when exposed to a cool temperate monsoon influenced climate herbivore and carnivore carbon isotopes 13c values from tooth enamel imply the presence of a woodland ecosystem dominated by coniferous trees such as araucariaceae and are consistent with the hypothesis that large sauropods and hadrosaurids were the preferred prey of tarbosaurus mean annual precipitation map based on the relationship between modern day c3 gymnosperms and local average map is estimated at 775 835 mm yr these results show that large theropod teeth can serve as valuable archives for palaeoenvironmental studies

oxygen and carbon stable isotope records of marine vertebrates from the type maastrichtian the netherlands and northeast belgium late cretaceous abstract stable isotope analysis of marine skeletal carbonates is an important tool for palaeoenvironmental reconstructions however in mesozoic sedimentary sequences diagenetic alteration often overprints the original skeletal carbonate isotope values yet even if carbonate diagenesis did occur in such sequences the original oxygen isotope values can still be preserved in enamel or bone phosphate of vertebrate fossils here are analysed the isotope compositions of tooth enamel structural carbonate and phosphate of various late maastrichtian and early palaeocene shark and ray taxa as well as carapace bone of a late maastrichtian marine turtle allopleuron hofmanni from the type area of the maastrichtian stage in the southeast netherlands and northeast belgium no correlation is observed between 18osc and 18op suggesting diagenetic alteration of at least one fraction in comparison to modern shark teeth oxygen isotope ratios of the maastrichtian palaeocene structural carbonate 18osc are significantly lower 5 as expected from previous isotope studies of calcitic fossils from the maastrichtian type area we believe the 18osc values to have been altered by meteoric diagenesis the oxygen isotope ratios of phosphate 18op in maastrichtian palaeocene shark and ray teeth are relatively wide ranging 16 9 to 25 0 vs vsmow with median values matching data for extant shark teeth 18op suggesting retention of the in vivo 18op signal similarly the 18osc in the cheloniid turtle a hofmanni is apparently overprinted by meteoric diagenesis while the cortical compact bone of the carapace is interpreted to reflect the in vivo 18op isotope composition using a phosphate water fractionation equation for biogenic apatite and median isotope values of late maastrichtian early palaeocene shark and ray teeth a seawater temperature of 19 7 c is calculated this is in good agreement with temperatures expected for the maastrichtian of this area carbon isotope analyses 13c of structural carbonate in shark teeth have yielded isotope ratios that agree well with those of modern subtropical sharks suggesting the in vivo carbon isotope signal to have been retained a comparison of a hofmanni bone carbonate 13c values with those of extant marine turtle species suggests a hofmanni to have had a carnivorous lifestyle also a hofmanni shows 13c values that are 10 lower than the average 13c of sharks and rays more similar to sympatric mosasaurs this distribution is interpreted to be the effect of respiratory physiology on 13c fractionation

oxygen isotopes from biogenic apatites suggest widespread endothermy in cretaceous dinosaurs the much debated question of dinosaur thermophysiology has not yet been conclusively solved despite numerous attempts we used the temperature dependent oxygen isotope fractionation between vertebrate body water 18obody water and phosphatic tissues 18op to compare the thermophysiology of dinosaurs with that of non dinosaurian ectothermic reptiles present day 18op values of vertebrate apatites show that ectotherms have higher 18op values than endotherms at high latitudes due to their lower body temperature and conversely lower 18op values than endotherms at low latitudes using a data set of 80 new and 49 published 18op values we observed similar and systematic differences in 18op values 18o between four groups of cretaceous dinosaurs theropods sauropods ornithopods and ceratopsians and associated fresh water crocodiles and turtles expressed in terms of body temperatures tb these 18o values indicate that dinosaurs maintained rather constant tb in the range of endotherms whatever ambient temperatures were this implies that high metabolic rates were widespread among cretaceous dinosaurs belonging to widely different taxonomic groups and suggest that endothermy may be a synapomorphy of dinosaurs or may have been acquired convergently in the studied taxa

palaeoenvironments of the late triassic rhaetian sea implications from oxygen and strontium isotopes of hybodont shark teeth the oxygen and strontium isotopic composition of 125 teeth of the hybodont sharks lissodus and hybodus from various late triassic rhaetian bone bed localities in the central european basin are used as environmental and ecological tracers for the shallow epicontinental rhaetian sea the preservation of tooth enameloid was ascertained by cathodoluminescence microscopy mean 18op values differ regionally across the rhaetian sea with values of 18 6 0 6 near the western gate 16 1 0 8 in the east 15 4 0 6 in the southeast and 17 7 0 9 in the south the 18op values in the eastern rhaetian sea are 4 5 lower relative to tethyan seawater while teeth from the southern and western parts close to the marine gates are less fractionated the strontium isotopic composition of teeth from most localities is more radiogenic in comparison to late triassic seawater the observed spatial 18op trend in the rhaetian sea indicates a shift from marine to brackish conditions in the south and west towards extensively brackish conditions with salinities of less than 16 in the east thus confirming the existence of two marine gates brackish conditions persisted throughout early rhaetian times and were maintained by increased fluvial discharge from the vindelician bohemian and fennoscandian highs as a result of enhanced atmospheric moisture availability in the course of the rhaetian transgression the 18op values of lissodus and hybodus indicate euryhaline behaviour of rhaetian hybodonts by exceeding modern shark intraspecific variability the lack of accordance in 18op values between different isotopically conspicuous localities in the rhaetian sea contradicts a basin wide migration pattern differences between co site taxa might indicate some degree of niche partitioning

rare earth element systematics of fossil bone revealed by la icpms analysis intra bone rare earth element ree fractionation trends were studied by la icpms analysis to put constraints on 1 the mechanisms controlling ree fractionation within fossil bones 2 the relative timing of ree uptake in various parts of fossil bone and 3 the origin of ree in fossil bones we have evaluated ree bone profiles across 54 fossil bones from a broad range of well characterised taphonomic settings ranging in age from triassic to early medieval ree patterns and concentration gradients are highly variable and intra bone fractionation trends in la yb n vs la sm n space of few specimens cover almost the entire range previously observed for bulk samples intra bone variability of ce anomalies as well as variable y ho and la la n is also observed sometimes diagenetic fluids with fractionated hree enriched compositions have entered the bone from the marrow cavity producing secondary ree uptake profiles theoretical intra bone fractionation trends modelled using lattice strain theory concur with most ree data but some trends cannot be modelled using realistic boundary conditions this fact as well as the occurence of positive and negative ce anomalies within the same fossil sample hint towards changing ree compositions of diagenetic fluids over the timescales of ree uptake because apparent ce anomalies frequently evolve over bone profiles and ce anomalies can be inherited from previous fractionation events ce anomalies are a highly ambiguous tracer for constraining ambient redox conditions in general bioapatite ree signatures may not always reliably reflect ambient taphonomic or redox conditions and diagenetic fluid compositions therefore ree patterns and ce anomalies of fossil bones must be interpreted cautiously as they vary spatially within skeletal remains and are affected by intra bone fractionation processes as well as changing compositions of the diagenetic fluid

the retention of primary oxygen isotope compositions of fossil elephant skeletal phosphate fossil elephant remains from sediments of plio pleistocene age in the vicinity of lake turkana kenya provide insights into the ability of the phosphate oxygen system to preserve original 18o values 18op in the depositional environment individual fossil specimens exhibit systematic variations in the 18op values of their various tooth and bone components differences in 18op values between these skeletal components can be as high as 3 6 despite the fact that equivalent phases for individual modern elephants have 18op values which vary by less than 0 6 xrd traces of the different skeletal phases of modern and fossil samples also infer differential preservation of primary apatite crystallinities among the various fossil phases fossil samples of dentine cementum and bone have x ray spectra with sharper and more intense peaks compared to their modern counterparts but little change in crystallinity is observed for fossil enamel samples a model based on the premise that the enamel phase preserves primary isotope signatures and that the accompanying skeletal phases are partially re equilibrated with the fluids associated with the microbial decomposition of the elephant s carcass is consistent with the features of the 18op dataset this isotopic evidence in conjunction with the physical and chemical attributes of enamel has led us to postulate that enamel could be preserving primary isotope signatures while other skeletal components are affected to varying degrees by alteration processes in the burial environment

diagenetic stability of the isotopic composition of phosphate oxygen palaeoenvironmental implications meteoric diagenesis of the lower pliocene varswater formation phosphate deposit cape province south africa has altered the chemistry of the francolite component the isotopic composition of the phosphate oxygen has been changed as have other chemical and isotopic parameters that are known to be susceptible to meteoric diagenesis from authors

δ 18 o of carbonate quartz and phosphate from belemnite guards implications for the isotopic record of old fossils and the isotopic composition of ancient seawater belemnite guards of cretaceous and jurassic age were found to contain varying amounts of quartz deposited both on the external surface and inside the rostrum the oxygen isotopic composition of coexisting carbonate quartz and phosphate from the same rostrum was measured according to well established techniques none of these compounds showed isotopic values in equilibrium with one another assuming 18o values of the diagenetic water within the range of meteoric waters the 18o sio2 yield temperatures in agreement with the apparent secondary origin of this phase the 18o co32 range with a certain continuity between 10 8 and 0 97 pdb 1 with most of the intermediate values being within the range of the carbonate isotopic values of mesozoic fossils the most positive isotopic results obtained from phosphate are close to 23 24 v smow they can hardly be related to a secondary origin of the phosphate or to the presence of diagenetic effects since these results are among the most positive ever measured on phosphate as far as we know there is no widespread diagenetic process determining an 18o enrichment of phosphate the very low concentration of phosphate did not allow the determination of its mineralogical composition all the available 18o po43 values from belemnite and non belemnite fossils of marine origin of tertiary and mesozoic age are reported along with the newly measured belemnites the following conclusions may be drawn from the data reported 1 the pristine oxygen isotope composition of fossil marine organisms either carbonate or phosphate may easily undergo fairly large changes because of oxygen isotope exchange processes with diagenetic water this process is apparent even in the case of geologically recent fossils 2 the 18o po43 of belemnite rostra seems to be at least in the case of the most positive results in isotopic equilibrium with environmental water because of the similarity between the results from cretaceous belemnites and the results from cretaceous and lower tertiary pelecypods and fish teeth 3 if so the only feasible interpretation that can be suggested for the 18o enriched data is the possibility of a relatively large variation of the oxygen isotopic composition of ocean paleowater from jurassic to recent time

analysis of the geochemical variability in lepisosteid scales from the fontllonga 3 site early danian tremp formation south central pyrenees spain implications for palaeoenvironmental studies rare earth element ree ba ca sr ca and 18opo4 analyses have been performed on the ganoine and isopedine of different types of isolated scales anterior middle posterior flank scales and dorsal body margin scales from juvenile lepisosteids from the fontllonga 3 site early danian tremp formation south central pyrenees spain with the aim of detecting the most suitable kind of scale to be used in palaeoclimate studies the ree flat shape patterns obtained in lepisosteid scales from fontllonga 3 are indicative of the absence of late stage diagenesis and recrystallization and have confirmed the identification of the palaeoenvironment where the fontllonga 3 lepisosteids inhabited to be that of an estuary the ba ca palaeothermometer shows that posterior flank scales record on average 4 52 c ganoine and 3 49 c isopedine higher temperatures when compared to middle flank scales which may be related to the fact that posterior flank scales grow preferentially during the warm season whilst middle flank scales which have the greatest number of layers of ganoine per unit of time and grow all year round record a greater amplitude with respect to palaeoenvironmental and palaeoclimatic variations temperature values obtained from anterior flank scales follow a pattern similar to that showed by middle flank scales whilst temperature values provided by dorsal scales resemble the pattern furnished by posterior flank scales the same relationship between scale position and temperature but to a lesser degree 1 48 c is also evident in the calculated 18opo4 temperatures the ba ca palaeothermometer was applied by considering ba ca ratios of the water for different types of environments and it has been found out that a ratio similar to that of marine waters yielded the best approximation to 18opo4 temperatures 29 82 3 76 c the mean ba ca temperature value obtained from the analysis of all the ganoine samples 26 96 5 72 c is also consistent with the temperature of the water in which extant relatives of osteoglossiform fish whose remains have been found in fontllonga 3 along with lepisosteid remains inhabit nowadays 24 40 c with mean values of 27 to 32 c the mean ba ca temperature values furnished by the isopedine are lower than that obtained on the ganoine which may be due to minor diagenetic alteration on account of these results it is recommended that a distinction should be made between different types of scales as this could provide information concerning the summer growth temperature posterior flank scales as well as the annual temperature range middle flank scales furthermore it is recommended that ganoine be used in all studies as it appears to be the most resistant tissue in lepisosteid scales to diagenetic alteration

high resolution records of location and stratigraphic provenance from the rare earth element composition of fossil bones abstract bone apatite acts as a natural timed sampling device scavenging trace elements from local pore waters over timescales of ca 1 50 ka the rare earth element ree and u th composition of fossil bones reflects associated pore water compositions during the period of recrystallisation the ree composition of fossil bones is controlled by partitioning of ree between pore waters and particle surfaces and the ree composition of fossil bones reflects the ree composition of pore waters which vary spatially and temporally light ree are preferentially sorped onto particle surfaces thus the high la yb values seen in many bones from coastal marine and aeolian environments are best explained by release of ree from light ree enriched particles to local pore waters and subsequent immobilisation in recrystallising bones the ree compositions of bones recovered from pedogenically altered diatomite sediments of the olorgesailie formation of southern kenya vary over spatial scales of less than 10 m location accounts for 48 of the observed variation in bone chemistry and bones recovered from eight discrete excavations within the same time equivalent stratigraphic layer can be assigned to their excavation location with 70 accuracy based on a discriminant analysis of ree u and th composition despite this within layer variation bones recovered from different stratigraphic horizons within the olorgesailie formation can also be distinguished on the basis of their trace element composition bones recovered from four stratigraphic horizons spanning ca 0 5 million years were assigned to their correct stratigraphic layer with 90 accuracy where sedimentological conditions are favourable the trace element composition of fossil bone may be used to test stratigraphic provenance and burial location in excavated bone with a temporal resolution of

rare earth element evolution of phanerozoic seawater recorded in biogenic apatites rare earth element ree contents of marine biogenic apatites have been shown to record seawater compositions a data base of available and newly acquired rare earth element ree contents of marine biogenic apatites has been created to assess the past seawater ree compositions to ensure that this data base contains only the pristine ree signals altered samples characterized by very low la sm n ratios where n stands for ree ratios normalized to the nasc composition gromet et al 1984 geochim cosmochim acta 48 1984 2469 acquired during apatite recrystallization are not included in the database these data reveal a change in the tethyan seawater composition between 110 and 80 ma after the end of the cretaceous the ree chemistry of seawater remains constant until present day this seawater composition change is likely due to concurrent changes in ree scavenging processes a strong correlation between decreasing sm yb n ratios and increasing ce anomalies for samples deposited during the 80 110 ma period is observed as ce anomalies are attributed to ocean water redox conditions changes in ree scavenging could reflect an evolution from stratified and poorly oxygenated waters towards well mixed and oxygenated waters this could have resulted from changing current patterns stemming from the contemporaneous opening of the atlantic ocean a major change in middle and late cretaceous oceanic circulation linked to plate tectonics would have favored the colonization of pelagic environments

preservation of successive diagenetic stages in middle triassic bonebeds evidence from in situ trace element and strontium isotope analysis of vertebrate fossils abstract bonebeds comprise reworked and time averaged constituents of different phosphatic vertebrate remains and hence provide an ideal substrate for the study of long and short term diagenetic processes to test whether trace elements u sr ree and 87 sr 86 sr ratios can be used for distinguishing between successive diagenetic signals we performed geochemical analyses on vertebrate remains bones teeth scales and coprolites from two triassic bonebeds located near palzem germany trace element analysis was done on 170 vertebrate remains by la icp ms while 87 sr 86 sr ratios were determined for 39 bioclasts using la mc icp ms although a low inter and intra bioclast ree variability indicates long term open system behaviour the observed ree patterns suggest the preservation of different diagenetic stages a distinct difference in the geochemical composition exists between dark luminescent sem cl domains and greyish ones dark domains represent dense diagenetically more resistant material of low porosities such as enamel and ganoine these domains display distinctly lower ree contents and a higher inter clast variability than those of various grey tones together with lower hence more seawater like 87 sr 86 sr ratios this argues for a preservation of an earlier diagenetic signal notably most dark domains are characterised by negative eu anomalies while all grey ones display positive eu anomalies with the exception of eu both domains display almost identical ree patterns with different concentrations indicating that late diagenetic ree uptake is not necessarily accompanied by fractionation processes in vertebrate bioclasts negative eu anomalies are most likely inherited from eu depleted surface waters possibly as a result of eu depleted aeolian input conversely positive eu anomalies were presumably affected by eu enriched late diagenetic fluids with a possible high temperature origin causing a fractionation of europium our study therefore demonstrates the potential of high resolution geochemical analysis in bonebed strata to disentangle different stages of diagenesis and to detect least altered areas in vertebrate fossils for recovering pristine palaeoenvironmental signals

middle late cretaceous climate of the southern high latitudes stable isotopic evidence for minimal equator to pole thermal gradients a detailed 18 o and 13 c stratigraphy has been generated from analysis of well preserved albian early maastrichtian foraminifera from deep sea drilling project dsdp sites 511 and 327 falkland plateau 58 s 62 s paleolatitude in the southern south atlantic and cenomanian and coniacian santonian foraminifera from dsdp site 258 naturaliste plateau 58 s paleolatitude in the southern indian ocean these results when combined with previously published maastrichtian stable isotope data from ocean drilling program odp site 690 weddell sea 65 s paleolatitude provide new insight into the climatic and oceanographic history of the southern high latitudes during middle late cretaceous time the planktonic foraminifer 18 o curves reveal a gradual warming of surface waters from the albian through the cenomanian followed by extremely warm surface waters from the turonian through the early campanian long term cooling of surface waters began in the late early campanian and continued through the end of the maastrichtian the benthic foraminifer 18 o record generally parallels changes in the oxygen isotopic curves defined by shallow dwelling planktonic foraminifera the vertical oxygen and carbon isotopic gradients were relatively low during the albian cenomanian high from the turonian early campanian and then low during the late campanian and maastrichtian foraminiferal oxygen isotopic data from published sources and this study are averaged for each site corrected for latitudinal changes in salinity based on modern day surface water values and plotted versus paleolatitude for the late albian coniacian santonian and late maastrichtian differences between lowand high latitude surface water paleotemperatures are estimated at 14 c during the late albian and late maastrichtian but the coniacian santonian reconstruction reveals only a 0 4 c latitudinal temperature gradient uncertainty regarding cretaceous salinity gradients and possible diagenetic alteration of 18 o values introduce error into our estimates of paleolatitudinal thermal gradients however apparent low equator to pole temperature differences could indicate much higher poleward heat transport than at present

oxygen isotope variations in phosphate of biogenic apatites iv mammal teeth and bones groups of rats grown from birth to death in identical conditions but with different 18o of drinking water w were studied for variations of 18o of their body water bw and bone phosphate p there is a high linear correlation r 0 99 between bw and between p and w the regression lines have similar slope coefficients 0 53 and 0 49 values of p of different teeth and bones are the same within the precision of the method 0 5 the isotopic fractionation coefficient between phosphate and body water is 1 0178 and close to the estimated value of 1 0173 derived from the phosphate paleotemperature equation deviations from constant fractionation between bone phosphate and environmental drinking water depend primarily on rates of drinking and metabolism environment conditions have relatively little effect on oxygen isotope fractionation between water sources and bone phosphate

taphonomy of the late cretaceous dinosaur bearing beds of the lano quarry iberian peninsula abstract the lano quarry located in the northern part of the iberian peninsula basque cantabrian region has yielded a diverse continental vertebrate assemblage from the late cretaceous late campanian to early maastrichtian the fossil assemblage consists of almost 40 species including bony fish amphibians lizards snakes turtles crocodilians dinosaurs pterosaurs and mammals lano is the most productive european vertebrate locality hitherto known from the late cretaceous the sedimentology of the lano section shows that the three associated fossiliferous beds known as l1a l1b and l2 were deposited in an alluvial system composed primarily of fluvial sands and silts the sedimentary structures are consistent with channel areas within an extensive braided river the l1a level was excavated in detail and mapped following a square metre grid system the main features of the multispecies vertebrate assemblage are as follows wide range of body size including microfossils large proportion of adult individuals rare articulated skeletal parts size sorting and dominance of small elements high spatial density long bones showing some preferential orientation variable dip variable degree of breakage and large proportion of splintering wide range of weathering and abrasion no evidence of predatory activity or chemical alteration on the basis of these features we suggest that the lano association lies between the taphonomic modes for attritional vertebrate assemblages in fluvial channels though it tends more toward the channel fill than the channel lag mode the l1a sample of lano is a heterogeneous assemblage of elements ranging from isolated bones and teeth to articulated skeletons with allochthonous and para autochthonous characteristics it consists of a mixture of vertebrates from different palaeocommunities and includes aquatic or semi aquatic elements and remains transported from a variety of habitats on the alluvial plain the dinosaur bones are commonly broken and show a greater degree of abrasion than those of freshwater vertebrates indicating that they may be allochthonous however actinopterygians amphibians pleurodiran turtles and eusuchian crocodilians are interpreted as being para autochthonous palaeobatrachid frogs bothremydid turtles and alligatoroid crocodilians are the most relatively abundant vertebrates of the lano fossil assemblage the occurrence of pelomedusid turtles and crocodilians is indicative of an intertropical warm climate

dinosaur bones fossils or pseudomorphs the pitfalls of physiology reconstruction from apatitic fossils abstract a prerequisite to any attempt to reconstruct thermophysiology of ancient animals through analysis of stable isotopes of oxygen is the assumption that apatitic fossils are isotopically unaltered parts of their original skeletons we suggest that sufficient evidence is available to seriously question this assumption because living bones contain about 1 3 by weight of organic matrix mass balance considerations show that at least half of an apatitic fossil must be new material added post mortem furthermore living apatitic skeletons contain almost no rare earth elements and uranium whereas apatitic fossils bear high concentrations of these elements additionally we found that while in living fish correlation between 18o of oxygen in the phosphate and that in the carbonate of apatite is poor these two values are linearly correlated in fossil fish this suggests diagenetic recrystallization has taken place perfect preservation of micro textures such as haversian canals does not prove the pristine condition of a fossil some of the most beautifully preserved fossils are highly silicified most apatitic fossils probably are pseudomorphs replacing original skeletal elements whereas distribution of stable isotopes of oxygen in fossils might provide information about their burial environment it could be misleading in attempts to interpret the organisms physiology this cautionary note is supported by the similarity of 18op in bones of coexisting fossil fish dinosaurs and various other reptiles at different latitudes the overlap of predicted 18op values in fish and mammals living in contact with the same environmental water also weakens the hope that ectotherms can be distinguished from endotherms by the isotopic composition of oxygen in their bones and teeth

planetary science magnetic impact craters aerial surveys of the vredefort impact crater in south africa suggest that it is only weakly magnetic the rocks themselves tell a different story but does this apply to giant impact basins on mars

oxygen isotope compositions of late jurassic vertebrate remains from lithographic limestones of western europe implications for the ecology of fish turtles and crocodilians oxygen isotopes can be used to reconstruct the palaeoenvironmental conditions in which vertebrates lived and thereby give an indication of their ecology this has been done for faunas from the famous late jurassic lithographic limestones of western urope oxygen isotope compositions of phosphate from apatite were measured in aquatic or semiaquatic vertebrate remains fish turtles and crocodilians deposited in these protected coastal marine environments the unknown water composition in the oxygen isotope fractionation equations between phosphate and water was solved for turtles by assuming that modern relationship between environmental water and turtle bone isotope compositions applies to the past the results show that 1 coastal marine waters were thermally homogenous at the regional scale of western europe 2 oxygen isotope data discriminate between coastal marine and freshwater to brackish water inhabitants 3 the plesiochelyid turtles were coastal marine inhabitants their 18o values allow the calculation of the oxygen isotope compositions of marine waters thus refining the estimate of water temperatures by combining 18o values from fish and 4 the marine isotopic signature and the cranial anatomy of plesiochelyid turtles lead us to propose that they had a salt excreting system i e the fundamental physiological feature that controls osmoregulation in the marine environment these late jurassic turtles are proposed to be the first know marine turtles several tens of million years before the chelonioids or sea turtles

the fossil vertebrates from lano basque country spain new evidence on the composition and affinities of the late cretaceous continental faunas of europe a newly discovered fossil locality at lano basque country has yielded a vertebrate assemblage of probably maastrichtian age comprising fishes amphibians reptiles and mammals it considerably enlarges our knowledge of the late cretaceous continental faunas of europe hitherto based on a much less complete record some taxa are recorded for the first time in europe and the fauna also contains the oldest known representatives of some groups amphisbaenians salamandrids the lan assemblage reveals an original fauna comprising both forms related to asian and north american groups and elements with gondwanan affinities

magnetic lineations in the ancient crust of mars the mars global surveyor spacecraft in a highly elliptical polar orbit obtained vector magnetic field measurements above the surface of mars altitudes 100 kilometers crustal magnetization mainly confined to the most ancient heavily cratered martian highlands is frequently organized in east west trending linear features the longest extending over 2000 kilometers crustal remanent magnetization exceeds that of terrestrial crust by more than an order of magnitude groups of quasi parallel linear features of alternating magnetic polarity were found they are reminiscent of similar magnetic features associated with sea floor spreading and crustal genesis on earth but with a much larger spatial scale they may be a relic of an era of plate tectonics on mars

oxygen isotope analyses of co existing carbonate and phosphate in biogenic apatite a way to monitor diagenetic alteration of bone phosphate abstract the oxygen isotopic composition of phosphate 18 op and structural carbonate 18 oc of hydroxylapatite was determined in 31 bone and tooth samples of modern mammals from different countries these two variables are highly correlate r 2 0 98 and the calculated best fit of linear regression is very similar to the equation calculated from the phosphate and carbonate palaeotemperature equations 1 2 according to previous measurements 3 6 on fossils of different ages from different areas it seems quite improbable to find isotopically altered skeletal remains showing a good correlation between 18 op and 18 oc as is the case with modern samples it therefore seems possible at least in some cases to use these measurements for monitoring fossil bone and tooth diagenetic alteration when a set of points lie on the equilibrium line or close to it the 18 o values could be considered close to the original values in contrast when the points lie to the left or to the right of this line this probably means that the values are diagenetically modified due to interaction with meteoric water or 18 o enriched water respectively

rare earth elements of shallow water articulated brachiopods a bathymetric sensor abstract variations in environmental physicochemical parameters result in corresponding changes in seawater rare earth element ree distributions for an archive to be utilized in paleoceanographic and paleoenvironmental reconstructions it should record these variations therefore an archive s proxy potentiality should be assessed analogous to modern oceanic settings articulated brachiopods of several shallow water localities the mean ree sn pattern of shallow water brachiopods is significantly different from that of their deep water counterparts with lower enrichments in lrees and mrees and depletion in hrees depth exercises a major control on the lree and mree fractionation with a milder one on hree fractionation the ce ce anomaly is not affected by either of these parameters in shallow water settings but in deep settings the depth effect dominates due to the importance of depth on ree fractionation in the shells from shallow settings their lree sn to hree sn ratios l h were divided into six discrete intervals for the bathymetric sensor the bathymetric sensor was applied to some fossils and whole rock in order to estimate their paleodepths the evaluation was successful in placing the permian gyanyima the pennsylvanian naco boggy and the silurian chicotte becscie and jupiter formations in shallow depths

geochemical study of vertebrate fossils from the upper cretaceous santonian csehbanya formation hungary evidence for a freshwater habitat of mosasaurs and pycnodont fish abstract the diverse vertebrate remains from the upper cretaceous freshwater settings at iharkut hungary contain two fossil groups pycnodontiformes fish and mosasauridae that are almost exclusively known from marine palaeo environments hence their appearance in alluvial sediments is very unusual trace element and isotope compositions of the remains have been analyzed to investigate the taphonomy and the ecological differences among the different fossil groups present at iharkut all examined fossils have undergone post depositional diagenetic alteration which resulted in high concentrations of ree u and fe together with almost complete homogenization of 18oco3 values similar ree patterns in different fossils suggest a common origin for all remains hence the discovered species most likely lived in the same local ecosystem despite partial diagenetic overprinting the 18opo4 values of the fossils indicate sufficient taxon specific isotopic diversity to permit some broad conclusions on the palaeo environment of the fossils in particular it is apparent that the isotopic composition of the pycnodontiformes fish and mosasauridae remains is most compatible with a freshwater palaeo habitat and incompatible with a marine palaeo environment in addition the sr concentration and isotope data indicate that the pycnodontiformes and mosasauridae likely lived predominantly in a freshwater environment and were not simply occasional visitors to the iharkut river ecosystem regarding other fossil groups high 18opo4 values of alligatoroidea and iharkutosuchus teeth suggest that these small crocodile species might have inhabited swamps and ponds where the water was relatively rich in 18o due to evaporation

crystal chemical controls on rare earth element concentrations in fossil biogenic apatites and implications for paleoenvironmental reconstructions abstract fossil biogenic apatites display rare earth element ree patterns which have been proposed to reflect environmental and biological controls on past seawater composition these patterns can be separated in two groups 1 patterns that are similar to those of open ocean and epicontinental waters and 2 patterns that exhibit a strong enrichment in intermediate ree bell shaped patterns because ree trapping in biogenic apatites occurs mostly post mortem it is essential to understand the crystal chemical inorganic factors that can influence the fractionation of ree between apatite and water a model is proposed by which partition coefficients of ree between apatite and water for a substitution mechanism can be extrapolated from mineral melt partition data to seawater or sedimentary basin conditions these are compared with available experimental partition coefficients for ree adsorption mechanism and used to discuss ree patterns in fossil biogenic apatites calculations of ree patterns for apatites at equilibrium with water show that the bell shaped patterns in fossil apatites can be explained by fractionation with seawater or continental fluids at low temperature under crystal chemical control involving a substitution mechanism and in the context of extensive or late diagenesis in that case the equilibrium composition of the fluid cannot be unequivocally determined from observed ree concentrations in fossil apatites this type of sample is inappropriate to discuss the past environmental or biological controls on ree concentrations in the ocean other sample compositions suggest little to moderate alteration of the original oceanic to freshwater pattern through the adsorption mechanism in the context of weak or early diagenesis and may be used with caution for that purpose

earthquake prediction a critical review summary earthquake prediction research has been conducted for over 100 years with no obvious successes claims of breakthroughs have failed to withstand scrutiny extensive searches have failed to find reliable precursors theoretical work suggests that faulting is a non linear process which is highly sensitive to unmeasurably fine details of the state of the earth in a large volume not just in the immediate vicinity of the hypocentre any small earthquake thus has some probability of cascading into a large event reliable issuing of alarms of imminent large earthquakes appears to be effectively impossible key word earthquake prediction

oxygen isotope variations in phosphate of biogenic apatites i fish bone apatite rechecking the rules of the game abstract the major advantage of the oxygen in phosphate isotope paleothermometry is that it is a system which records temperatures with great sensitivity while bone and teeth building organisms are alive and the record is nearly perfectly preserved after death fish from seven water bodies of different temperatures 3 23 c and different 18 o values 16 to 3 of the water were analysed the 18 o values of the analysed po 4 vary from 6 to 25 the system passed the following tests a the temperatures deduced from isotopic analyses of the sequence of fish from lake baikal are in good agreement with the temperatures measured in the thermally stratified lake b the isotopic composition of fish bone phosphate is not influenced by the isotopic composition of the phosphate which is fed to the fish but only by temperature and water composition isotopic analysis of fossil fish in combination with analysis of mammal bones should be a useful tool in deciphering continental paleoclimates

la icp ms analysis of rare earth elements in marine reptile bones from the middle triassic bonebed upper silesia s poland impact of long lasting diagenesis and factors controlling the uptake abstract the rare earth elements ree contained in fossil bones are widely used for provenance and palaeoenvironmental studies earlier works suggested that the ree uptake is limited to early diagenesis but more recent research provided evidence of long term open system diffusion in fossil bones we analysed thin walled reptile bones all collected from the same middle triassic 245 ma marine bonebed comprising vertebrate remains of likely different ages to check the influence of the long term diagenesis on the concentrations of ree in terms of impact of pore water the upper parts of the bones are contained in a low permeability crinoidal limestone whereas their lower parts have been affected by diagenetic fluids for a long time we measured ree and other trace element contents in 29 bones using la icp ms totally 660 spots in 45 depth profiles neither the absolute concentrations of the ree and the ree intra bone paas normalised patterns nor the inter element ratios and the la ce and eu anomalies appear useful to distinguish between the likely older and younger bones in the bonebed the mree n enrichment combined with the flat intra bone distributions of the ree lead to conclusion that ree fractionation and substitution for ca were the most important processes responsible for the selective uptake the low permeability host rock and diagenetic fluids had a significant impact on the trace element uptake and their intra bone distribution patterns the lower parts of the bones that likely had a long lasting contact with the diagenetic fluids reveal a relative enrichment in the ree and their easier diffusion into the bone centres the ability of fossil bones to incorporate trace elements over a long time span strongly limits the usage of particularly the older samples for provenance and palaeoenvironmental reconstructions additionally the presented new analyses fill the gap between the available databases of trace element concentrations in fossil bones with regard to middle triassic samples

oxygen isotope compositions of phosphate from middle miocene early pliocene marine vertebrates of peru phosphatic remains of marine vertebrates recovered from five fossil sites of the pisco formation ranging from the latest middle earliest late miocene ca 11 13 ma to the early pliocene ca 3 5 ma have been analysed for their oxygen isotope compositions 18op coexisting seals dolphins whales penguins and sharks from each locality have distinct 18op values reflecting ecology and physiology differences ranging from 18 2 to 21 4 for marine mammals from 19 5 to 21 5 for marine birds and from 20 9 to 23 1 for sharks systematic offsets observed between dolphin teeth and bones as well as between dolphin and whale bones indicate that the fractionation equation established by using data from extant cetaceans may not be directly applicable to miocene cetaceans in order to estimate water 18ow values assuming that polar ice caps were not totally developed during this time interval marine palaeotemperatures ranging from 13 0 1 3 c to 17 2 1 3 c were estimated comparison of our results with those obtained in other world s areas suggests that the oxygen isotope ratios of pisco vertebrates reflect the influence of both global and local events such as the setting of the atacama desert the cold humboldt current or the global phases of ice cap growth and decay

oxygen isotope fractionation between crocodilian phosphate and water oxygen isotope compositions of phosphate 18op were measured in tooth enamel from captive and wild individuals of 8 crocodilian species a rough linear correlation is observed between the 18op of all the studied species and the oxygen isotope composition of ambient water 18ow differences in mean air temperature diet and physiology could contribute significantly to the large scatter of 18op values the combination of these parameters results in a fractionation equation for which the slope 0 82 is lower than that expected 1 from predictive model equations that assume temperature and diet as fixed parameters taking into account large uncertainties the observed oxygen isotope fractionation between phosphate and ambient water does not statistically differ from that formerly established for aquatic turtles case studies show that 18op values of fossil crocodile tooth enamel can be used to discriminate between marine and freshwater living environments within a precision of about 2 only

warm palaeotemperatures from high late jurassic palaeolatitudes falkland plateau ecological environmental or diagenetic controls abstract oxygen and carbon isotopes have been determined from late jurassic oxfordian tithonian belemnites and inoceramid bivalves from two deep sea drilling project dsdp sites located on the falkland plateau mean belemnite 18o values derived from well preserved skeletal material were 1 29 from dsdp site 330 and 1 45 from dsdp site 511 assuming a seawater smow value of 1 0 mean palaeotemperatures calculated from the oxygen isotopic composition are 17 2 c and 17 9 c respectively the inoceramid bivalves yielded much lighter 18o values mean 3 58 petrographic and geochemical evidence points to the inoceramid bivalves being altered by diagenesis which accordingly accounts for the observed differences in isotopic values vital effects or the importation of belemnites or inoceramids from another area are considered not to account for the observed isotopic trends the palaeotemperatures interpreted from the belemnites are significantly warmer than other recent estimates of late jurassic temperature from oxygen isotope studies and climate model predictions from similar southern palaeolatitudes we suspect our apparent warmer temperatures are because of a combination of increased freshwater runoff depleting surface waters with respect to 18o and related to the semi enclosed nature of the depositional basin retaining warmth relative to the open ocean of similar latitudes

intra tooth study of modern rhinoceros enamel δ18o is the difference between phosphate and carbonate δ18o a sound diagenetic test abstract the carbonate and phosphate oxygen isotopic difference 18 o c p has been suggested as a test for diagenetic alteration of isotope values in fossil apatite samples the generally accepted 18 o c p value for well preserved enamel is 9 only a few studies have focussed on the potential natural variability of this difference in modern and fossil mammal teeth the aim of this study is to document the value of the carbonate phosphate oxygen isotopic fractionation factor co3 po4 at an intra tooth level we measured the enamel phosphate and carbonate oxygen isotopic compositions of two upper molars m1 and m2 of rhinoceros unicornis following a sequence from the apex to the cervix of the crown the average co3 po4 is 1 0082 0 0007 the mean value of the 18 o c p difference is 8 4 0 7 close to the literature values given for other species however we also show that the values of the 18 o c p difference for r unicornis upper molars can vary on a 2 range in the same tooth we develop a physiological model to explain the origin of inter species and intra tooth 18 o c p difference and to understand their implications on the status of 18 o c p as a tool for identifying diagenesis the results imply that by increasing the dataset of phosphate and carbonate oxygen isotopic composition for modern mammal species we will be able to define a maximal and precise envelope corresponding to the well preserved samples and to check a possible species dependence on the 18 o c 18 o p relationship

oxygen isotopes in phosphatic fish remains from israel paleothermometry of tropical cretaceous and tertiary shelf waters the isotopic composition of oxygen in phosphate was measured on 24 fossil fishes from israel and jordan ranging in age from cretaceous to eocene from these the first paleotemperatures were calculated for shallow water cretaceous paleotropics the results were compared to those of fish from other mediterranean localities and to late cretaceous marine reptiles from israel 18o in the fish average 18 0 in the early cretaceous 17 8 in the cenomanian 18 3 in the coniacian 18 2 in the santonian 19 4 in the campanian 20 1 in the maastrichtian and 18 4 in the early eocene such variations suggest a warm cenomanian turonian cooling towards the end of the cretaceous and warming up again in the eocene the deduced temperatures for the cretaceous range between 20 c and 34 c which is about 10 higher than cretaceous water surface temperatures in northern europe apatite from marine reptile skeletons yields similar 18o to coexisting fish the good agreement between these and previously known paleotemperature data give further credence to the validity of paleotemperatures obtained by isotopic analysis of oxygen in phosphates the relatively large thermal gradient between middle and low paleolatitudes favors barron s 1983 coolest cretaceous model

brachiopods as indicators of original isotopic compositions in some paleozoic limestones the original stable isotopic composition of paleozoic marine carbonate rocks is important to establish a baseline for evaluating diagenetic alteration and providing a reliable data base for modeling exogenic geochemical cycles of the elements we have compared the 18 o and 13 c values in the nonluminescent portions of brachiopods with similar published data of whole brachiopods other whole fossils and estimates of original isotopic composition of marine cements the oxygen and carbon isotopic records for each of these paleozoic components show generally good internal consistency significant discrepancies however were noted between results on the different components isotopic and trace element data presented in this study suggest that permo carboniferous whole brachiopods are little altered chemically nonetheless a more reliable but not fool proof approach for obtaining pristine isotopic values is microsampling of least altered regions based on cathodoluminescence in conjunction with staining techniques and elemental analyses the carbon and oxygen isotopic compositions of all components decrease in 18 o and 13 c in geologically older material neither temporal trend is monotonic however oxygen isotopic results suggest an important positive shift in 18 o of about 2 during the early carboniferous whereas the carbon isotope trend shows a major positive shift 2 3 during the mid carboniferous

oxygen isotope measurements of mammoth and reindeer skeletal remains an archive of late pleistocene environmental conditions in eurasian arctic 58 samples of fossil mammoth and reindeer teeth and bones of various ages and coming from different locations were studied for the oxygen isotopic composition of their phosphate samples from siberia have interstadial marine isotope stage 3 stadial mis 2 late glacial and post glacial ages russian and ukrainian samples refer to the late glacial and transitional between the interstadial and glacial stages time the 18o of palaeoenvironmental waters were calculated from the 18op obtained from fossil samples by means of the isotope equations calibrated on modern specimens of elephants and deer respectively the 18ow obtained are generally lighter than those measured nowadays in the same areas and not far from those measured on ice cores of holocene age the isotopic differences being not greater than a few units the calculated values are also in fairly good agreement with some isotopic values obtained from siberian permafrost samples according to the results obtained it seems that the elephant and deer equations can be reasonably used respectively in the case of fossil mammoth and deer skeletons to evaluate environmental palaeowaters

oxygen and carbon isotope compositions of middle cretaceous vertebrates from north africa and brazil ecological and environmental significance in order to investigate mid cretaceous terrestrial climates of low paleolatitudes moroccan tunisian and brazilian vertebrate apatites have been analyzed for their oxygen and carbon isotope compositions of phosphates delta 18 o p and carbonates delta 18 o c delta 18 c c at each site coexisting theropod dinosaurs titanosaurid sauropods pterosaurs crocodilians turtles and fish have distinct delta 18 o p and delta 18 c c values reflecting their ecologies diets and foraging environments oxygen isotope compositions of surface waters delta 18 o w estimated from turtle and crocodile delta 18 o p values range from 5 0 1 0 parts per thousand to 2 4 1 0 parts per thousand which do not differ from mean annual rainwater values occurring today under inter tropical sub arid to arid climates high water temperatures ranging from 21 6 degrees c to 34 2 degrees c deduced from fish delta 18 o p values are in agreement with those published for mid cretaceous low latitudes temporary or seasonal droughts are inferred from high delta 18 o p values of lungfish teeth even though lower reptile delta 18 o p values suggest the use of distinct and most likely larger or regularly renewed bodies of water environmental conditions of the studied low latitude regions during the aptian cenomanian interval were somewhat similar to those experienced today under semi arid to arid tropical or equatorial climates but with higher mean surface temperatures than present day ones

multiproxy reconstruction of the palaeoclimate and palaeoenvironment of the middle miocene somosaguas site madrid spain using herbivore dental enamel profound palaeoclimatic changes took place during the middle miocene the miocene climatic optimum 20 to 14 13 5 ma was followed by a sudden 200 ka decrease in temperature and an increase in aridity around the world as a consequence of the reestablishment of the ice cap in antarctica somosaguas palaeontological site madrid basin spain has provided a rich record of mammal remains coincident with this global event middle miocene biozone e 14 1 13 8 ma it contains four fossiliferous levels t1 t3 1 t3 2 and t3 3 with t1 being the oldest that span an estimated time of 105 125 ka scanning electron microscope sem and rare earth element ree analyses performed on herbivore tooth enamel gomphotherium angustidens anchitherium cf a cursor conohyus simorrensis prosantorhinus douvillei and ruminants indicate that diagenetic processes have not been intense enough as to obscure the original geochemical signal stable isotope 18oco3 13cco3 and 18opo4 analyses have been measured on the herbivore tooth enamel across these levels with the aim of determining to what extent the global cooling and aridity pattern is recorded at this site a decrease in 18oco3 and 18opo4 has been detected from t1 to t3 3 and t3 1 to t3 3 respectively indicating a progressive drop of about 6 c from around 18 c to 12 c in mean annual temperatures within t3 tooth enamel 13c values experience an increase from t3 1 to t3 3 suggesting an increase in aridity ba ca analyses have also been performed on the tooth enamel in order to detect changes in the palaeoecology of the studied taxa this ratio allows the establishment of particular feeding patterns such as a more browsing habit in the case of gomphotherium angustidens compared to anchitherium cf a cursor as suggested by higher ba ca values in the latter trace elements do not support any significant change across the succession in the dietary behaviour of the species analyzed despite the stable isotopes evidence of an important palaeoclimatic shift from t1 to t3 3

δ18o and ree contents of phosphatic brachiopods a comparison between modern and lower paleozoic populations 18o values of both carbonate 18 7 25 1 and phosphate 15 1 16 7 components of the francolite from the fossil brachiopod shells are interpreted as the result of a partial resetting of pristine isotopic compositions the similarity of hat shape ree patterns of some lower ordovician linguloids with those of extant littoral specimens suggests the preservation of a 500 myr old record of ree marine chemistry in agreement with the known paleogeography the phosphatic brachiopods have been deposited in a coastal environment under shallow and oxygenated marine waters however the contents and distribution of ree in some strongly altered brachiopod shells reveal an alteration of the original negative ce anomalies and both nd and sm enrichments that transformed the initial hat shape patterns of linguloids into strongly convex or bell shape patterns

fossil crocodilians as indicators of late cretaceous and cenozoic climates implications for using palaeontological data in reconstructing palaeoclimate abstract that the earth s climate has cooled over the last 100 million years has been recognized since the early nineteenth century the transition from the hot house world of the cretaceous a time interval without significant polar icesheets to the ice house world in which we now live today the dynamics process responsible for this change are being examined using computer models especially general circulation models gcm s through such work our understanding of the dynamics of the earth system improves and our ability to predict future trends is enhanced but the success of modelling experiments can only be assessed by comparing results with observations the pattern which for palaeoclimate are drawn exclusively from the geological record palaeoclimate interpreted from geological data is invariably based on analogy with the recent the validity of which depends on corroboration from multiple lines of evidence this requires the compilation and investigation of large global datasets of well constrained geological climate proxies this study uses the palaeodistribution of fossil crocodilians to examine the spatial distribution of palaeoclimate during this transition fossil crocodilians have a relatively good fossil record and are climatically limited in the recent they also provide a manageable global dataset with which to investigate other issues that impinge on the use of geologic data for reconstructing palaeoclimate taphonomy sampling effects time averaging tectonics and for fossils palaeobiogeography and evolution as such this study provides a possible template for examining other climate proxies in order to validate and hone palaeoclimatic interpretations an analysis of modern crocodilians indicates that temperature is the principal influence on their global distribution with the coldest month mean temperature cmm of 5 5 c marking the minimum thermal limit for the group corresponding today to a minimum mean annual temperature mat of 14 2 c the duration of warmth during the year partly indicated by the mean annual range of temperature mart is also important as this affects early juvenile development and survival the presence of standing water provides an essential thermal buffer against temperature extremes by analogy the palaeodistribution of fossil crocodilians suggests the following during the late cretaceous and early palaeogene mat s in excess of 14 2 c cmm s 5 5 c permeated throughout mid latitudes and coastal regions in high latitudes during the oligocene the restriction of fossil crocodilians to low latitudes suggests high latitude cooling as indicated by numerous other lines of evidence coeval restriction of crocodilians to coastal regions in mid latitude north america and much of asia consistent with increased seasonality and aridification in continental interiors may reflect local orographic changes as well as global climate change during the miocene fossil crocodilians return to the great plains of north america but do not reoccupy the continental interior of asia by the pliocene crocodilians are again restricted to low latitudes and coastal regions in mid latitudes coincident with further high latitude cooling and aridification and cooling of mid latitude continental interiors minor distributional changes during the holocene may reflect human effects

ratios of cave bear tooth enamel a record of climate variability during the pleistocene the oxygen isotope composition of apatitic phosphate in the teeth and bones of certain animals reflects the oxygen isotope composition of the water they ingest the isotopic composition of meteoric water is in turn well correlated with mean annual temperature so that there is potential for recovering paleotemperatures of the regions where the animals lived cave bear teeth have been examined for this purpose analyses were made of enamel from 53 canine teeth of cave bears males females adults and juveniles from 4 sites in spain phosphate was isolated as ag3po4 and reacted with graphite to produce co2 for isotopic analysis reproducibility of the analyses was normally 0 1 0 2 the oxygen isotope compositions of teeth from both the coastal site of cueva de santa isabel 350 200 ka and the inland site of cueva mayor 350 ka were uniform 1 4 total variation per site with mean 18o values of 18 9 and 17 2 respectively interpretations of these data include differences in global temperature between glacial and interglacial periods and differences due to geographic locations of the sites e g elevation and distance from the sea the teeth from cueva del reguerillo 90 60 ka in central spain were more variable in isotopic composition with an average value between those of teeth from the other caves cave bear teeth appear to preserve their original oxygen isotope composition can be dated and occur in abundance in many locations of europe and the near east the abundance of the teeth and their large size allows samples used for paleoclimate studies to be restricted to enamel of one type of tooth the 18o values of enamel and dentine from one tooth commonly differ thus the comparison of oxygen isotope composition among teeth from different individuals sites or times is facilitated if only enamel is used restricting analyses to only one type of tooth reduces variability due to changes of diet during the period of tooth growth the simple evolutionary line of descent of cave bears and the small number of species reduces the effects of interspecific differences in oxygen isotope fractionation they thus provide a good potential source of material for detailed investigations of pleistocene climates

environment and ecology of east asian dinosaurs during the early cretaceous inferred from stable oxygen and carbon isotopes in apatite abstract during the cold late barremian early albian interval terrestrial environments in east asia were populated by rich and diverse vertebrate faunas characterized by a strong provincialism the latitudinal gradient of temperature and the existence of geographic barriers likely accounted for some aspects of this heterogeneous distribution of faunas other factors however such as local environmental conditions and interactions within vertebrate communities which could have influenced their distribution have not yet been fully identified and understood therefore new and published oxygen and carbon isotope compositions of apatite from chinese and thai reptiles dinosaurs crocodilians and turtles have been analyzed and interpreted in terms of ecology local air temperature and precipitation amounts differences in carbon and oxygen isotope compositions between various groups of sympatric plant eating dinosaurs sauropods ornithopods and ceratopsians indicate food resources partitioning among them most likely to avoid competition mid latitude environments where the jehol biota flourished were submitted to cool temperate climatic conditions with mean air temperature mat of 10 4 c and mean annual precipitations map of about 600 mm yr compatible with the existence of forest environments by contrast sub tropical regions characterized by mat of about 20 25 c were either submitted to high amounts of seasonal precipitations of about 1200 mm yr in thailand or to significant aridity map of about 400 mm yr in south china this difference in precipitation regime between thailand and south china may be attributed to the occurrence of the coastal cordillera extending along the east margin of the south china block these mountain ranges likely prevented humid air masses from the pacific to penetrate some parts of south china thus generating a rain shadow effect mosaic environments characterizing east asia during the late early cretaceous may have acted as a cradle for the origination of advanced dinosaur taxa that subsequently radiated over eurasia and north america during the late cretaceous

oxygen isotope composition of continental vertebrate apatites from mesozoic formations of thailand environmental and ecological significance phosphatic remains tooth enamel turtle shell fragments and fish scales of continental vertebrates freshwater fish crocodilians turtles and theropod and sauropod dinosaurs recovered from eight localities of ne thailand ranging in age from the late jurassic to the late early cretac eous have been analysed for their oxygen isotopic compositions d 18 op from these preliminary data local meteoric water d 18 ow values estimated using d 18 op values of crocodilians and turtles range from 24 1 2 at the end of the jurassic to 28 3 2 during the early cretaceous suggesting a transition from dry to wetter climates with increasing amount of seasonal precipitation from several hundred millimetres per year to several thousand millimetres measurable offsets in d 18 op values observed between dinosaur taxa the spinosaurid theropod siamosaurus other ther opods and nemegtosaurid sauropods are interpreted in terms of differences in water strategies and suggest that siamosaurus had habits similar to those of semi aquatic vertebrates such as crocodi lians or freshwater turtles

the implication of the oxygen isotope records in coexisting cherts and phosphates 18 o values have been determined for 53 coexisting chert phosphate pairs from the phanerozoic and precambrian in addition 18 o values were also determined for 18 biogenic phosphates from the phanerozoic the oxygen isotope data for the chert phosphate pairs permit the calculation of the temperatures of formation of the chert phosphate pairs as well as the 18 o of the waters in which they equilibrated in turn the calculated 18 o of the waters permit the calculation of temperatures from the isotopic data of the biogenic phosphates the temperatures for the tertiary and mesozoic samples are compatible with the literature values determined from oxygen isotope data for well preserved calcareous marine skeletal remains the temperatures calculated from the chert phosphate pairs of the paleozoic are usually higher and vary in cycles of about a 150 million year period the early precambrian temperatures are as high as 80 c and decrease with time the use of chert phosphate pairs for temperature determinations are sufficiently promising to warrant further investigations of this type on well preserved chert phosphate or carbonate phosphate pairs

palaeomagnetism of the vredefort meteorite crater and implications for craters on mars magnetic surveys of the martian surface have revealed significantly lower magnetic field intensities over the gigantic impact craters hellas and argyre than over surrounding regions the reduced fields are commonly attributed to pressure demagnetization caused by shock waves generated during meteorite impact in the absence of a significant ambient magnetic field lower than average magnetic field intensities are also observed above the vredefort meteorite crater in south africa yet here we show that the rocks in this crater possess much higher magnetic intensities than equivalent lithologies found elsewhere on earth we find that palaeomagnetic directions of these strongly magnetized rocks are randomly oriented with vector directions changing over centimetre length scales moreover the magnetite grains contributing to the magnetic remanence crystallized during impact which directly relates the randomization and intensification to the impact event the strong and randomly oriented magnetization vectors effectively cancel out when summed over the whole crater seen from high altitudes as for martian craters the magnetic field appears much lower than that of neighbouring terranes implying that magnetic anomalies of meteorite craters cannot be used as evidence for the absence of the planet s internally generated magnetic field at the time of impact

oxygen isotopic composition of fossil equid tooth and bone phosphate an archive of difficult interpretation abstract variation in the concentration of the stable isotopes of hydrogen oxygen and carbon have been tested in continental records as tools for quantitative or semi quantitative paleoclimatological studies among the different methods the potential use of oxygen isotopes in mammal bone and tooth phosphate has recently been recognized measurements carried out on fossil mammal bones of holocene age and their paleoclimatological interpretation corresponded well with paleontological and paleobotanical records in the case of considerably older fossils diagenetic processes may change the primary oxygen isotopic composition of phosphate fossil horse bones and teeth principally of the species equus stenonis were studied to ascertain how far back in time fossil mammal remains may be considered reliable material for paleoclimatological studies the samples come from 13 different locations in southeastern spain their age ranging from maspinian late pleistocene to middle villafranchian pliocene apart from the variations of the 18o po43 values which may be related to climatic changes it is apparent that the isotopic composition of bones and teeth from the same deposit are frequently rather different from one another the isotopic differences range from a few tenths of one to several this suggests a strong influence of taphonomy over the measured isotopic values of fossils in each deposit time can be considered neither the only variable nor the most important one responsible for the change of the primary isotopic composition of fossils under these conditions it is rather difficult to establish lower or upper limits for the age of fossils to be studied for reliable paleoclimatological information since the limits are directly related to taphonomic history this in turn is related to local environmental conditions and not only to the age of fossils

variability of trace element uptake in marine reptile bones from three triassic sites s poland influence of diagenetic processes on the host rock and significance of the applied methodology abstract diagenetic alternation of apatite building vertebrate bioclasts is a complex process it is influenced by numerous factors but the impact of diagenetic processes affecting the host rock is commonly underestimated the present study aims at identifying the causes of different concentration levels and distribution patterns of ree and at examining the significance of the material chosen for normalisation we measured ree and other trace element concentrations in three bone assemblages of triassic marine reptiles using la icp ms and in the host rocks using icp ms two groups of hard parts reveal clearly different trace element contents and distribution patterns the remains from gogolin show a distinct mreen enrichment which must have been caused by replacement involving numerous substitutions that was possible due to a relatively high porosity of the host rocks and the presence of pore water the mreen enrichment and low concentrations of mg and sr combined with a relatively high content of u in these bones indicate solutions derived from meteoric water as the source of the incorporated ions the reductive dissolution of fe oxyhydroxides that are abundant in the host rock matrix and that likely were an important source of ree may have influenced and controlled the ree uptake the significant hreen enrichment over lreen as revealed in the rust coloured bones from raciborowice gorne is likely connected with local acidification of the pore water resulting from aqueous oxidation of pyrite infilling the pore spaces in the bones the material selected for normalisation of the chemical composition of apatite can have a significant impact on values of the normalised data used further for interpretations particularly when vertebrate bioclasts from carbonate host rocks are involved the carbonate rocks have element ratios that differ from those characterising the commonly used paas and nasc normalisation materials in particular ce anomaly values can distinctly vary depending on the applied normalisation procedure vertebrate hard parts that definitely spent more time in a host rock than in an animal body must be rigidly handled as a constituent of a specific rock never as a separate item

oxygen isotope composition of vertebrate phosphates from cherves de cognac berriasian france environmental and ecological significance abstract the european record of continental vertebrates during the earliest cretaceous berriasian is usually based on accumulation assemblages in littoral localities where faunas of various living environments and ecologies are mixed a recently excavated site located in the southwest of france cherves de cognac corresponds to a hyper saline lagoonal environment that has yielded a rich vertebrate fauna including brackish and freshwater fish amphibious crocodilians and turtles as well as terrestrial dinosaurs and mammals while some of these taxa were most likely parautochthonous others may have been transported from distant environments in order to decipher the respective living environments of these vertebrates and better understand the local climatic conditions apatite phosphates of their teeth or bones have been analyzed for their oxygen isotope compositions from these preliminary measurements differences in phosphate 18op values observed between taxa most likely reflect differences in sources of ingested waters that are compatible with their assumed ecologies reconstructed 18ow values of environmental waters using po4 water fractionation equations show that marine and brackish waters were submitted to enough evaporation for generating a hypersaline lagoon as reflected by 18ow values ranging from 1 7 to 1 7 whereas the more inland freshwaters have 18ow values ranging from 4 1 to 1 8 the lowest water 18ow value of about 4 estimated from the 18op value of terrestrial mammals which is assumed to be the composition of local meteoric waters leads to estimate a mean air temperature of about 20 3 c at cherves de cognac during the berriasian 30 35 n such temperatures are recorded today at similar latitudes however a weak equator to pole thermal gradient is evidenced by the latitudinal distribution of thermophilic taxa such as crocodilians

low latitude sea surface temperatures for the mid cretaceous and the evolution of planktic foraminifera isotopic data from exceptionally well preserved foraminifera show that the subtropical north atlantic had sea surface temperatures ssts between 30 and 31 c during the late albian and early cenomanian these temperatures were warmer than average modern temperatures in the tropical western atlantic and support previous inferences based on diagenetically suspect material of albian tropical ssts of 30 c this finding is consistent with basic theories of oceanic thermal response in the tropics to the high atmospheric carbon dioxide levels during the middle cretaceous greenhouse however our data do not support the concept of a super tethyan region of hypersaline waters in the western north atlantic during late albian and early cenomanian time because seawater salinities substantially higher than modern ones would require significantly higher ssts than those reported here isotopic analysis of mid cretaceous planktic foraminifera shows that planomalina ticinella and biticinella grew in surface waters and provide isotopic proxies for sst whereas deeper growing species include hedbergella rotalipora and praeglobotruncana none of these taxa display isotopic indications of photosymbiosis suggesting that this ecology did not evolve in planktic foraminifera before the late cretaceous contrary to previous hypotheses none of these species increased their depth habitat during their life cycles unlike many extant planktic foraminifera the rotaliporids may have been preferentially susceptible to extinction during oceanic anoxic events because they lived within or below the thermocline for most of their life cycles

stable isotopic characterisation of francolite formation stable isotopic data are presented for 112 samples of francolite from 18 separate phosphate deposits values of 13c and 34s in most offshore deposits suggest formation within oxic or suboxic environments either by carbonate replacement or direct precipitation of francolite from water of normal marine compositions the exceptions are concretionary francolite from namibia which has an isotopic composition in keeping with its formation within organic rich sediments and that from offshore morocco which has an isotopic signature of the anoxic suboxic interface onshore deposits from jordan mexico south africa and possibly the permian phosphoria formation in the western u s a are substantially depleted in18o they appear to be too altered for deductions to be made about their environments of formation in other onshore deposits which are unaltered or minimally altered the isotopic composition suggests that some formed within sulphate reducing sediments sedhura morocco whilst francolite from the georgina basin of australia formed at the oxic anoxic boundary where oxidation of biogenic h2s decreases the 34s of pore water in general pelletal samples show non oxic isotopic signatures whilst non pelletal samples show oxic isotopic signatures but samples from namibia peru ica plateau and the californian and moroccan margins are exceptions to this rule morphology may therefore be a misleading indicator of francolite genesis as no definitive relation exists between phosphorite type and isotopic signature

oxidative conditions can lead to exceptional preservation through phosphatization exceptional preservation through phosphatization is primarily controlled by a reduction in ph favoring the precipitation of apatite over that of calcite laboratory experiments have suggested that phosphatization results from anoxic decay here we report results of the fine scale mineralogical characterization of cretaceous phosphatized fossils of teleost fishes and crustaceans from the jebel oum tkout lagerstatte morocco data collected using complementary laboratory and synchrotron based x ray techniques reveal that oxidative conditions were established at a certain step of decay supporting these conclusions are the presence covering and embedded in the phosphatized tissues of fe iii rich mineral phases the precipitation of which was likely biologically induced during decay the present study highlights that the establishment of oxidative conditions during decay can be compatible with exceptional preservation of fossils through phosphatization

oxygen isotopes of east asian dinosaurs reveal exceptionally cold early cretaceous climates early cretaceous vertebrate assemblages from east asia and particularly the jehol biota of northeastern china flourished during a period of highly debated climatic history while the unique characters of these continental faunas have been the subject of various speculations about their biogeographic history little attention has been paid to their possible climatic causes here we address this question using the oxygen isotope composition of apatite phosphate from various reptile remains recovered from china thailand and japan values indicate that cold terrestrial climates prevailed at least in this part of asia during the barremian early albian interval estimated mean air temperatures of about 10 4 c at midlatitudes 42 n correspond to present day cool temperate climatic conditions such low temperatures are in agreement with previous reports of cold marine temperatures during this part of the early cretaceous as well as with the widespread occurrence of the temperate fossil wood genus xenoxylon and the absence of thermophilic reptiles such as crocodilians in northeastern china the unique character of the jehol biota is thus not only the result of its evolutionary and biogeographical history but is also due to rather cold local climatic conditions linked to the paleolatitudinal position of northeastern china and global icehouse climates that prevailed during this part of the early cretaceous

recent research on the physical aspects of earthquakes abstract recent developments in the field of physical aspects of earthquakes which encompasses in present day terminology the analysis of focal dynamics and of catastrophic effects of earthquakes are reviewed in particular individual sections of this review deal with the earthquake source effects of earthquakes on the ground the geographic and temporal distribution of earthquakes the characterization of seismic risk earthquake prediction and with the artificial release of earthquakes in this instance the review supplements earlier information by the author 1975 by new data published mainly between 1975 and 1984

thermal excursions in the ocean at the cretaceous tertiary boundary northern morocco δ18o record of phosphatic fish debris c lecuyer p grandjean j r o neil h cappetta and f martineau 1993 thermal excursions in the ocean at the cretaceous tertiary boundary northern morocco c lso record of phosphatic fish debris palaeogeogr palaeoclimatol palaeoecol 105 235 243 high precision oxygen isotope analyses were made of phosphate extracted from 17 samples of nektonic and benthic fish debris sampled across the stratigraphic cretaceous tertiary boundary in northern morocco a refinement of the silver phosphate method was used to isolate phosphate from biogenic materials measured 180 values of 18 6 20 5 o are interpreted as reflecting high resolution thermal variations that affected the ocean water column of the western tethys the warm 27 c water masses that characterized maastrichtian times underwent rapid cooling and stabilized at an average temperature of 19 c during the dano montian and thanetian this period of constant and cool temperature was followed by a relatively rapid but more gradual warming to about 25 c achieved in the middle ypresian significant small shifts in 6180 values between nektonic and benthic fauna recorded only during the stages of rapid warming or cooling may correspond to averaged thermal differences within the water column that developed in response to global climatic changes the indicated temperature distribution could have been caused by thermal changes in the atmosphere rather than some signal carried by deep ocean currents the oxygen isotope data coupled with previous measurements of ree and end ti on the same samples support the suggestion that paleo pacific westward currents progressed as far as the northwestern part of the african platform at the end of the cretaceous period

isotope geochemistry of oxygen and carbon in phosphate and carbonate of phosphorite francolite oxygen isotope ratios in phosphate delta sup 18 o sub p were determined in 219 samples of phosphoritic rocks from all major phosphogenic provinces of the world ranging in age from lower proterozoic to recent in 58 samples oxygen was analyzed in the two oxygen lattice sites of francolite both in phosphate and in structural carbonate delta sup 18 o sub c delta sup 13 c was also analyzed in the latter and in coexisting calcite for 10 of them both delta sup 18 o sub p and delta sup 18 o sub c decrease sharply from the recent to the cretaceous and decrease with a gentler slope to the precambrian the nature of the time variation is elucidated by means of a delta sup 18 o sub p vs delta sup 18 o sub c plot which suggests that a the main cause of the time trends is the increase in temperature between recent and the cretaceous b the pre cretaceous trend is overprinted by both low temperature nonequilibrium exchange between sup 18 o depleted water and the rocks and higher temperature exchange between phosphate and carbonate c the observed trend cannot be explained by sup 18 o depleted cretaceous and paleozoic oceans the calcite coexisting with apatite in phosphatic rocks is similar in both delta sup 18 o and delta sup 13 c to the structural carbonatemore of the apatite even though phosphate may exchange its oxygen with environmental water to a greater extent than the authors originally claimed it is probably still a very good isotopic recorder of sedimentary environments less

tooth enamel stable isotopes of holocene and pleistocene fossil fauna reveal glacial and interglacial paleoenvironments of hominins in indonesia abstract the carbon 13 c and oxygen 18 o isotope compositions of fossilized animal tissues have become important proxies of paleodiet and paleoenvironment but such stable isotope studies have not yet been extensively applied to the fossil assemblages of sundaland the biogeographical region comprising most of the indonesian archipelago here we use the isotope composition of tooth enamel to investigate the diet and habitat of bovids cervids and suids from several holocene and pleistocene sites on java and sumatra our carbon isotope results indicate that individual sites are strongly dominated by either c 3 browsers or c 4 grazers herbivores from the padang highlands sumatra and hoekgrot java cave faunas were mainly c 3 browsers while herbivores from homo erectus bearing sites trinil and sangiran java utilized an almost exclusive c 4 diet the suids from all sites show a wide range of 13 c values corroborating their omnivorous diet for the dataset as a whole oxygen and carbon isotope values are positively correlated this suggests that isotopic enrichment of rainwater and vegetation 18 o values coincides with an increase of c 4 grasslands we interpret this pattern to mainly reflect the environmental contrast between glacial drier more c 4 and interglacial wetter more c 3 conditions intermediate herbivore 13 c values indicating mixed c 3 c 4 feeding is relatively rare which we believe to reflect the abruptness of the transition between glacial and interglacial precipitation regimes in sundaland for seven homo erectus bone samples we were not able distinguish between diagenetic overprint and original isotope values underlining the need to apply this isotopic approach to homo erectus tooth enamel instead of bone importantly our present results on herbivore and omnivore faunas provide the isotopic framework that will allow interpretation of such homo erectus enamel isotope data

earthquake prediction 1982 overview short term earthquake prediction represents a more difficult scientific problem than most of us thought 5 yr ago when the national earthquake hazards reduction program commenced and our progress has not been as rapid as initially hoped at this point reasons can be cited for both encouragement and discouragement despite slow progress the goal of short term prediction remains realistic and research should continue vigorously albeit with some changes in scientific strategy in contrast progress in long term prediction and hazard evaluation has been far more rapid than initially envisaged

stable isotope composition and rare earth element content of vertebrate remains from the late cretaceous of northern spain lano did the environmental record survive abstract oxygen and carbon isotope measurements have been performed on phosphatic remains from faunal associations dinosaurs crocodiles turtles and fish of the late cretaceous continental and marine sediments from northern spain basque country the environmental meaning of the oxygen isotope record in fossil reptiles is discussed on the basis of known paleoecology modern fauna analogs and apatite chemistry rare earth elements ree co32 and po43 contents fossil remains in sandstones and argillites from two localities urria and cuezva have low down to 16 and scattered 18o po4 co3 and 13c values with ree patterns characterized by strong middle ree enrichments these geochemical compositions of the biogenic apatites have most likely been acquired during a multi stage late diagenesis involving complete recrystallization of the apatite in the presence of aqueous fluids ree contents of fossils preserved in the clayey sands from the site of lano suggest that samples have only been affected by early diagenesis despite the diversity of analyzed taxa and the close association of marine sharks and rays and freshwater species crocodiles and turtles evolving in a littoral environment the narrow range of phosphate 18o values is interpreted as reflecting the temperature and isotopic composition of groundwaters that prevailed in the burial environment the potential information relative to the physiology and thermal regime of the vertebrates has been erased during the process of early diagenesis if all oxygen in the phosphate has exchanged with groundwaters the oxygen isotope composition of vertebrate remains suggests that a warm climate t 20 25 c prevailed in northern spain during the late cretaceous

positive cerium anomaly in the doushantuo cap carbonates from the yangtze platform south china implications for intermediate water column manganous conditions in the aftermath of the marinoan glaciation abstract oxygenation exerted an important control on the emergence and diversification of metazoans in the aftermath of the marinoan glaciation however the relationship between the oceanic dissolved o2 do levels and early metazoan evolution remains equivocal to provide a temporal and spatial reconstruction of the redox conditions for this critical interval this study investigates the early ediacaran cap carbonate deposits within intra shelf facies at three localities in the three gorges area the yangtze platform south china trace and rare earth elements are sequentially extracted from the carbonate fraction for pristine temporal seawater signals the member ii dolostones of the duoshantuo formation which overlies the cap carbonates show a negative ce anomaly no ce anomaly is observed in the lower units of the cap carbonates in contrast positive ce anomalies ce ce 1 3 in the uppermost part of the cap carbonates are observed in all studied sections these positive ce anomalies are accompanied by high mn fe ratios ranging from 5 04 to 14 96 and slightly positive mree anomalies suggesting that a fe mn oxyhydro oxide coparticipation occurred during the cap carbonate deposition the positive ce anomalies may result from the reductive dissolution of the ce enriched mn oxyhydro oxides across a mn iv mn ii redoxcline in a distinct manganous water wedge that was sandwiched between well oxygenated and anoxic ferruginous deep water layers this wedge may have exhibited low oxygen conditions with approximately 10 m do dissolved oxygen in comparison to the 90 m do expected in an oxic setting and 0 m do in an anoxic setting therefore the presence of a positive ce anomaly in the uppermost part of the cap carbonates indicates a new intermediate manganous condition and further elucidates the water column redox structure that existed following the end of the marinoan glaciation early ediacaran metazoans were possibly restricted to fully oxygenated conditions and were absent in the manganous or ferruginous rich environments

oxygen and strontium isotopes from fossil shark teeth environmental and ecological implications for late palaeozoic european basins article i nfo fossil shark remains occur in both marine and nonmarine late palaeozoic deposits therefore their palaeo ecology is controversial the oxygen and strontium isotopic composition of biogenic fluorapatite in 179 teeth scales and spines predominantly of hybodontid lissodus and xenacanthiform orthacanthus xenacanthus bohemiacanthus triodus sharks from various late carboniferous moscovian to early permian artinskian basins of europe are used as ecological tracers to decipher diadromous or obligate freshwater lifestyle of the investigated taxa the 18 op values of the different shark teeth range from 11 7 to 20 2 within the different basins with mean values of 16 9 0 5 for the bohemian massif 16 2 0 8 for eastern germany 18 2 1 0 for southwestern germany 18 5 0 7 for southern central spain 17 6 0 4 for