u series dating of fossil teeth and carbonates from snake cave thailand abstract snake cave thailand is an important site for the study of the evolution in southeast asia leading to a discovery of rich and various faunas including a human tooth fossils of large and small mammals converge to indicate on the basis of faunal assemblage a late middle pleistocene age for the fossiliferous layers on the other hand previous u series dating of carbonates furnished a lower limit for the fossils of about 130 ky in order to achieve a better comprehension of the chronology of the cave the uranium series method for absolute age determination has been applied to some carbonates older than those studied previously and to fossils themselves we used the isochron technique approach to yield valuable ages because spleleothem samples consist in a mixture of calcite and detrital contamination the results obtained suggest that the main fossiliferous level is older than about 160 ky the application of the u series method to tooth samples from this tropical cave leads to erroneous ages probably because of post depositional groundwater movements

restrictions on fluorine depth profiling for exposure age dating in archaeological bones archaeological fragments of bone and teeth that are exposed to a humid environment take up fluorine from the surrounding soil the fluorine ion replaces the hydroxyl group in the mineral phase of the bone forming chemically more stable fluorapatite in cortical parts of the long bone diaphysis a fluorine concentration profile can be observed which decreases from the outer surface and the marrow cavity towards the inner parts of the bone matrix geological time spans are needed for this process to reach equilibrium and for the distribution to become uniform as the shape of the profile which can be described by a diffusion model contains information on the exposure duration of the fossil object several attempts to use fluorine profiling as a dating method have been undertaken the distribution of fluorine in an archaeological sample however is strongly influenced by environmentally induced processes of bone diagenesis i e alteration in the structure and composition of the mineral phase and degradation of organic components that may make the time information indistinct the primary chemical composition of bones can thus be obscured by diagenesis within tens hundreds or thousands of years this depends more on the diagenetic environment than on the geological age to observe the impact of environmental influence on the profile shape samples from several burial sites featuring various soil conditions have been analyzed for their fluorine distribution and preservation state this paper provides an overview on the restrictions that have to be considered when attempts are undertaken to relate a fluorine diffusion pattern to the archaeological age of a bone specimen

the precision of porosity measurements effects of sample pre treatment on porosity measurements of modern and archaeological bone abstract bone porosity plays an important role in the taphonomic trajectory of bones porosity analysis of archaeological material can indicate diagenetic events in the bones taphonomic history furthermore measuring the porosity of modern bone material can potentially provide a method for assessing the relative likelihood of survival for different skeletal elements here we critically assess the use of nitrogen adsorption porosimetry and mercury intrusion porosimetry for analysing porosity of a range of bone preservation types from modern fresh material to highly degraded archaeological material in addition a number of sample preparation methods were assessed our results indicate that bone porosity measurements show large variation which may limit their usefulness when analysing modern material features observed in pore size distribution graphs are however consistent and thus this data would appear to be a useful indicator of diagenetic processes that have occurred in the bone the most effective method for preparation of the bone is lyophilisation which renders the bone dry enough for analysis and does not appear to cause a visible systematic error in the measurements

early diagenesis of bone and tooth apatite in fluvial and marine settings constraints from combined oxygen isotope nitrogen and ree analysis abstract fossil bones and teeth of late pleistocene terrestrial mammals from rhine river gravels rs and the north sea ns that have been exposed to chemically and isotopically distinct diagenetic fluids fresh water versus seawater were investigated to study the effects of early diagenesis on biogenic apatite changes in phosphate oxygen isotopic composition 18opo4 nitrogen content wt n and rare earth element ree concentrations were measured along profiles within bones that have not been completely fossilized and in skeletal tissues bone dentine enamel with different susceptibilities to diagenetic alteration early diagenetic changes of elemental and isotopic compositions of apatite in fossil bone are related to the loss of the stabilizing collagen matrix the ree concentration is negatively correlated with the nitrogen content and therefore the amount of collagen provides a sensitive proxy for early diagenetic alteration ree patterns of rs and ns bones indicate initial fossilization in a fresh water fluid with similar ree compositions bones from both settings have nearly collagen free ree u f and sr enriched altered outer rims while the collagen bearing bone compacta in the central part often display early diagenetic pyrite void fillings however ns bones exposed to holocene seawater have outer rim 18opo4 values that are 1 1 to 2 6 higher compared to the central part of the same bones 18opo4 18 2 0 9 n 19 surprisingly even the collagen rich bone compacta with low ree contents and apatite crystallinity seems altered as ns tooth enamel 18opo4 15 0 0 3 n 4 has about 3 lower 18opo4 values values that are also similar to those of enamel from rs teeth therefore ree concentration n content and apatite crystallinity are in this case only poor proxies for the alteration of 18opo4 values seawater exposure of a few years up to 8 kyr can change the 18opo4 values of the bone apatite by 3 therefore bones fossilized in marine settings must be treated with caution for palaeoclimatic reconstructions however enamel seems to preserve pristine 18opo4 values on this time scale using species specific calibrations for modern mammals a mean 18oh2o value can be reconstructed for late pleistocene mammalian drinking water of around 9 2 0 5 which is similar to that of late pleistocene groundwater from central europe

now a bone then calcite abstract critical transformation and degradation of skeletal tissues most frequently affect their organic components while the mineral component of bones and fossils comprises one of the most stable mineral groups on earth the apatites the case we present here relates to fossil bones from palaeolake shores whose shapes are preserved within the sediment itself but which disintegrate into a chalky disaggregated substance at the slightest touch or breath the rarity of bone apatite transformation into calcite is due to the extreme insolubility and stability of bone mineral which is highly tolerant of ionic substitutions and inclusions without changing its basic mineral nature and composition observation of this chalky substance under high magnifications reveals a delicate structure of microcrystals these crystals enclose microtunnels and grooves identical in shape and size to the characteristic bone bioerosion caused by aquatic microorganisms this microtunnelling preservation allows us to confirm that disaggregate calcite crystals replaced areas where once there had been bone furthermore the bone chalky material transformation had to occur when microorganisms were still in the interior of these tunnels otherwise the delicate empty microtunnels observed today would have collapsed two calcareous palaeo lakeshore sites show identical phenomenon detailed taphonomic environmental and chemical studies indicate that the transformation process was initiated by microorganisms arising from a combination of their metabolism and the alkaline environment they inhabited that caused a local and sudden increase in local acidity this chalky material is referred to as biogenic in contrast to environmental calcite deposits geodes and calcite infilling bone fissures that formed in the lake conditions the calcium carbonate phase of both biological and environmental origin in these two palaeolakes is aragonite which forms under restricted situations of aridity and warming and may provide a precise indication of environmental conditions when these sites formed similar situations may occur today in arid areas

bone diagenesis and origin of calcium phosphate nodules from a hominid site in the lukeino formation tugen hills kenya the lukeino formation 6 09 5 68 ma kenya is a fossiliferous fluvio lacustrine sedimentary sequence 100 m thick which yielded the fossil remains of the oldest east african bipedal hominid called orrorin tugenensis at one of the hominid sites aragai centimetric to pluri centimetric indurated calcium phosphate nodules occur in a specific sedimentary layer mineralogical and geochemical analyses coupled with sem optical microscopy and cathodoluminescence observations were performed on four calcium phosphate nodules and one bone showing differential alteration with characteristics locally similar to that of the nodules in order to determine the nature and origin of these nodules a crystallinity index ci and histological index hi were also assigned to these samples to characterize their degree of transformation analyses reveal that all nodules and the studied bone have a similar mineralogical and chemical composition nodules show no internal structure and are composed of a carbonate fluorapatite matrix including feldspars clays and spheres of iron and manganese oxides their high ci indicates significant recrystallization compared to modern bone the altered bone shows infilling of the trabecular cavities characterized by a clay deposit along the walls oxide spheres with a silica center and carbonate fluorapatite baguettes in the highly altered area of the bone a phenomenon of dissolution and dismantlement of bone structures adjacent to an area characterized by the presence of a phosphate matrix is observed the genesis of these calcium phosphate nodules seems to result from an advanced stage of transformation of bones due to a combination of physical chemical and biological bacterial processes the different stages of diagenesis are characterized by the incorporation of components from the sedimentary layer including diatoms and by neoformations of clays and oxides in the bone pores the bone structure is affected by fracturing and dissolution of carbonate hydroxylapatite which reprecipitated in bone cavities under the form of carbonate fluorapatite automorphic crystals then the bone structures and mineral neoformations were affected by a dismantlement phenomenon which increased the dissolution of the bone apatite this resulted in a carbonate fluorapatite matrix in which no trace of the initial bone structure is visible this particular mechanism of genesis of calcium phosphate nodules most probably takes place by action of fluid circulation in a confined environment such as a lake edge or marsh

pre screening techniques for identification of samples suitable for radiocarbon dating of poorly preserved bones under certain environmental conditions post depositional diagenetic loss of bone collagen can severely reduce the number of bones from a particular archaeological site that are suitable for stable isotopic analysis or radiocarbon dating this study examined nearly 300 bones from 12 archaeological sites across southern england known to yield poor or variable preservation to try to identify one or more pre screening technique s that would indicate suitable collagen preservation for radiocarbon dating the most reliable method was shown to be the percent nitrogen n of whole bone powder which has an 84 chance of successfully predicting whether or not a bone will yield sufficient i e 1 weight collagen for dating

identification of degraded bone and tooth splinters from arid environments using palaeoproteomics abstract the analysis of the skeletal remains of vertebrates in archaeological contexts provides information about human animal relationship and their environment their taxonomic identification based on macroscopic observation is not always possible due to fragmentation and poor preservation in recent years proteomics has emerged as an alternative but there is clearly a lack of data in arid environment where diagenesis rapidly affects the integrity of bone proteins here we report the efficiency of three protocols for protein extraction the protocols used harsh 1 m hcl and 0 6 m hcl and soft tris edta decalcification agents and were tested on unidentified splinters from the 2000 years old site of toteng botswana the preservation of the organic phase was first estimated using attenuated total reflectance fourier transform infrared spectroscopy and a set of samples with contrasted collagen contents were selected for palaeoproteomics the extracted proteins were submitted to a bottom up proteomic approach involving trypsin digestion followed by ultra high performance liquid chromatography coupled to mass spectrometry uhplc ms our results identify tris edta buffer as the most suitable decalcification protocol for poorly preserved bones and propose a collagen content threshold of 3 weight content for successful detection of peptides this approach combined with biogeographical and chronological repartitions of mammals in africa allows refining taxonomic attributions for four out of nine splinters leading to species identification data are available via proteomexchange with identifier pxd010725

bone diagenesis in the european holocene ii taphonomic and environmental considerations we have applied cluster analysis to mercury intrusion porosimetry data from 219 archaeological bones 121 human and 98 animal and soil chemistry data from 219 accompanying soil samples 1 per bone sample to investigate the influence of soil chemistry on bone preservation the samples chosen for the study were obtained from sites ranging in time from the pre modern to the mesolithic and were representative of burial environments across europe from the baltic to the mediterranean these results represent the single largest database for archaeological bone preservation in the european holocene to date and demonstrate the potential for large scale diagenetic studies to help develop long term preservation strategies for our european heritage despite the variety of sites and environments bones could be categorised into only four main diagenetic types furthermore soil chemistry appears to significantly affect only one type of preservation the pathway characterised by loss of mineral in neutral to basic soils taphonomy and in particular the differences between the treatment of human and animal remains becomes the dominating factor in determining preservation using these results strategies for heritage management of archaeological sites can be suggested grouping sites into those requiring immediate excavation and those where in situ preservation is viable

two phase southward subduction of the mongol okhotsk oceanic plate constrained by permian jurassic granitoids in the erguna and xing an massifs ne china abstract geodynamics of the mongol okhotsk oceanic plate southward subduction are still pending problems this paper presents new zircon la icp ms u pb age and whole rock geochemical data for the middle permian to middle jurassic granitoids in the western erguna and central xing an massifs 267 264 ma 241 ma and 173 ma i type granites and 216 ma a type granites were identified in the erguna and xing an massifs ne china the i type granites were produced by partial melting of the lower mafic crust the 216 ma a type granites were derived from partial melting of crustal materials with tonalitic to granodioritic compositions the 267 264 ma and 241 ma i type granites were generated in an andean type arc setting wheras the 216 ma a type and 173 ma granites were formed in supra subduction extensional setting we summarized previous age data of the middle permian to middle jurassic magmtaic rocks in the erguna and xing an massifs and identified two isolated phases of magmatic activity including the ca 267 225 ma and ca 215 165 ma periods with a significant magmatic gap at ca 225 215 ma these middle permian to middle jurassic magmatic rocks are closely related to the southward subduction of the mongol okhotsk ocean a two stage tectonic evolutionary model was proposed to account for these geological observations in the erguna and xing an massifs involving permian to middle triassic continuous southward subduction of the mongol okhotsk oceanic plate and late triassic to jurassic slab rollback and supra subduction extension

micromorphological indicators for degradation processes in archaeological bone from temperate european wetland sites abstract micromorphological investigations of archaeological bones make it possible to study decay processes and the associated depositional environment in one go a selection of micromorphological thin sections from soil samples from three wetland sites in switzerland the netherlands and norway that contained bone fragments were studied the goal was to investigate the type and the timing of decay processes to better understand the taphonomy of bones in such sites using optical microscopy and scanning electron microscopy with energy dispersive x ray spectroscopy sem edx a range of biological decay processes and chemical mineralogical transformations were observed in two of the sites zug riedmatt in switzerland and hazendonk in the netherlands a relatively short exposure to adverse conditions must have occurred some of the bones from zug riedmatt show localized collagen decay related to exposure to fresh ashes others show cyanobacterial tunnelling related to submersion in shallow clear water in hazendonk bone fragments and fish scales apparently have first been exposed to bacterial decay related to putrefaction subsequently alternations between wet and dry conditions resulted in the dissolution of some of the bone mineral and the formation of ca fe iii phosphates probably mitridatite fungal decay caused extensive tunnelling of bone and fish scales as well as the secondary phosphates these processes apparently ended when the bone rich layer became permanently waterlogged and anoxic in stavanger bone mineral is transformed into mitridatite and possibly other ca fe iii phosphates indications that the redox conditions are variable at present suggest that these processes are still active

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

a new taphonomic bioerosion in a miocene lakeshore environment abstract this study describes a new type of taphonomic alteration of fossil bone that occurred in a continental carbonate palaeolake environment at the reference spanish miocene site of cerro de la garita concud teruel scanning electron microscopy showed this type of alteration to be characterized by microtunnels that penetrate inward from the bone surface and by a branching meandering arrangement of microchannels on the bone surface these microtunnels had a highly electron dense inner wall seen as a characteristic rim in transverse section microspheres were seen inside the microtunnels both this electron dense layer and these microspheres were found to be composed of calcium phosphate these taphonomic modifications bear some similarities to but also differs from those caused by bacterial attack on bone and enamel in marine and terrestrial environments suggesting the present process to be a new type of bioerosion the microspheres inside the microtunnels were similar in size shape and composition to the fossilized bacteria covering fossils from fossil lagersttaten palaeolake sites such as libros teruel spain and messel germany under the transmission electron microscope these structures showed an apparent cell wall suggesting them to be fossilized coccoid bacteria

mineral microbial structures in a bone of the late cretaceous dinosaur saurolophus angustirostris from the gobi desert mongolia a raman spectroscopy study abstract bones while buried undergo diagenetic transformations the intensity of which depends on a variety of geochemical factors microbial degradation is one of the main processes acting on bones during early diagenesis we present mineral microspheres formed during bone diagenesis from the inner walls of the left tibia of the late cretaceous dinosaur saurolophus angustirostris from the gobi desert mongolia the microspheres occur either as individual bodies from a few micrometers to about 70 m in diameter or aggregated in clusters micro raman analysis shows that the microspheres are composed of various fe oxides mostly hematite and goethite that form regular reddish brown rings with organic matter at their cores the bone itself is composed for the most part of diagenetically transformed carbonate fluorapatite calcite cement was identified around the spheres and at points of contact with bone tissue negative ce anomalies indicative of ce iv in the diagenetic environment indicate oxic burial conditions all the size distribution of the microspheres their mode of occurrence and the presence of organic matter in cores surrounded by concentric fe oxide envelopes indicate early diagenetic microbially mediated mineralization in aerobic conditions the presence of microspheres and other mineral phases in the studied bone gives evidence of at least two mineralization episodes 1 fe oxide formation during an early diagenetic microbial attack on the bone and 2 later calcite barite gypsum cementation

diagenesis in bone and enamel apatite carbonate the potential of density separation to assess the original composition abstract this paper presents a new approach to the isotopic measurement of diagenetically altered archaeological bone apatite carbonate we describe how the existing differential dissolution method may be combined with a new approach to remove diagenetically reformed material on the basis of its greater specific gravity we show that heavier more diagenetically altered fraction has a higher altered 13 c and also increased crystallinity within one individual in addition we proposed one potential tool to check the validity of bone carbonate by comparing bone collagen enamel carbonate and bone carbonate values of 13 c and radiocarbon content from the same individual in the case of danebury cattle we estimated the biogenic 13 c apa value for dc83 and dc89 although it is still difficult to overcome diagenesis in order to meet the expected value which is shown to be 1 9 dc83 and 3 5 dc89

petrous bone diagenesis a multi analytical approach abstract the discovery of petrous bone as an excellent repository for ancient biomolecules has been a turning point in biomolecular archaeology especially in adna research but excessive and uncontrolled sampling could result in loss of this valuable resource for future research this study reports on the histological optical microscopy physical ftir atr elemental chn and biochemical collagen and dna analysis preservation of 15 human petrous bones spanning from the c 2100 bce to 1850 ce through the combined application of a number of diagenetic parameters general histological index infrared splitting factor carbonate phosphate ratio amide phosphate ratio col wt c n and c n of whole bone and collagen endogenous dna we provide new insights into petrous bone micromorphological characteristics and diagenesis and new evidence to enhance screening practices for adna and collagen analysis

contextualising the dead combining geoarchaeology and osteo anthropology in a new multi focus approach in bone histotaphonomy abstract histotaphonomy has become an important area of research in funerary archaeology it focuses on diagenetic alterations in bone microstructure and the reconstruction of post mortem processes microbial bioerosion is the most common diagenetic change observed in archaeological bone and its probable causes have been the subject of ongoing discussions this paper presents a new integrative approach that combines methods from physical anthropology and geoarchaeology the aim is to contextualise samples in regard to their sedimentary milieu sediment type the sedimentation processes they underwent and the specific archaeological features they originate from the analysis is based on 208 human and animal skeletal fragments from the late la tene site of basel gasfabrik recovered from various feature types and embedded in different sediments both 80 m and 30 m thin sections were graded semi quantitatively on a scale of 0 or 1 to 5 in regard to bacterial attack bai wedl tunnels wti cyanobacterial attack cai the formation of cracks cri the collagen content coi and thermal alterations hei our results evinced no correlations between the intensity of bacterial attack and sediment types or sedimentation processes respectively we therefore deduce that bacterial degradation of bone is mainly caused by endogenous gut bacteria wedl tunnels on the other hand are chiefly found in bones from exposed surfaces bone collagen content as measured by birefringence is dependent on a variety of factors with thermal alteration being among the most important unlike the 80 m sections used in anthropological investigations the 30 m thin sections typically utilized in geoarchaeological analyses permitted a reliable distinction of microbial bioerosion types our context oriented histotaphonomic approach allows detailed conclusions on the causes of microbial bioerosion in bone moreover it provides an important tool for reconstructing the post mortem biographies of human and animal remains especially in regard to multi stage mortuary practices and the analysis of sedimentation processes thus this novel approach generates a wealth of information from individual skeletal elements as well as from bone fragments embedded in soil samples

use of micro computed tomography imaging and porosity measurements as indicators of collagen preservation in archaeological bone abstract collagen isolated from archaeological bone is a common material for radiocarbon dating stable isotope analysis and zooarchaeology by mass spectrometry zooms however not all bones contain extant collagen leading to unnecessary destruction of unproductive bones and wasted laboratory time and resources an aim of this research is to study bone diagenesis particularly collagen destruction in an effort to develop a minimally destructive method for identifying bones with high collagen content in a multi method study of variably preserved bones from etton cambridgeshire uk we examined material properties of neolithic cattle and sheep bones including porosity surface area and elemental composition micro computed tomography microct is an imaging technique that furnishes three dimensional images of mineralized materials such as bone cortical bone porosity the percentage of total bone volume consisting of empty space as calculated using microct can act as a proxy for bone collagen preservation in general bones with high cortical porosity are unlikely to contain sufficient collagen for further analysis bones with apparently low cortical porosity have a more varied range of collagen preservation bone samples with low porosity and no extant collagen often contain micropores with a diameter of 10 nm or less that cannot be seen in microct images but are apparent in pore size distributions measured by mercury porosimetry and indicated by high surface areas measured by nitrogen adsorption furthermore a re evaluation of light induced breakdown spectroscopy data from this same assemblage confirms that ratios of calcium to fluorine may likewise indicate the state of diagenesis

middle cambrian to permian subduction related accretionary orogenesis of northern xinjiang nw china implications for the tectonic evolution of central asia abstract middle cambrian to permian subduction related records are widely distributed in northern xinjiang which can be grouped into the chinese altay east junggar eastern tien shan west junggar yili and tarim domains by integrating paleogeographic and geological data we suppose that the chinese altay east junggar eastern tien shan domain was more closely located to siberia while the west junggar and yili domains occupied an intermediate position near the kazakhstan block in the early paleozoic paleoasian ocean distribution of andean type magmatic arcs island arcs accretionary wedges ophiolitic slices and or microcontinents shows an archipelago paleogeography forming a huge accretionary active margin sequences the tarim domain was on the opposite side of the early paleozoic paleoasian ocean remaining passive margin these tectonic units drifted northwards and approached the southern active margin of the siberian craton in the late paleozoic leading to termination of the paleoasian ocean and formation of a complicated orogenic collage between siberian craton and the tarim block between the end permian and triassic these multiple accretion processes significantly contributed to the lateral growth of central asia

bacterial origin of iron rich microspheres in miocene mammalian fossils abstract in their taphonomic study of a cretaceous dinosaur fossil from the gobi desert mongolia kremer et al 2012 noted that the histological sections of this fossil preserved within their core iron oxide microspheres containing carbonaceous matter they interpreted the carbonaceous nature of these structures as organic matter and suggested a microbial origin probably bacterial for the structures microspheres similar both in composition and shape have been identified in fossils from cerro de la garita a miocene mammalian site in teruel spain in the latter case compact bone was also attacked by terrestrially associated bacteria microscopic focal destruction mfd which were enriched in iron and gives support to the idea that bacteria acted as the biological agent for iron precipitation during soft tissue decomposition in the early stages of bone diagenesis subsequent diagenetic episodes of mineralization related to the environmental context differ between these two sites calcite precipitation at the palaeo lakeshore of cerro de la garita and calcite and gypsum in the gobi desert study case of kremer et al 2012 if the microsphere is bacterial in origin it may be a useful taphonomic indicator of terrestrial exposure within a transitional environment of land and water

calcite moonmilk crystal morphology and environment of formation in caves in the italian alps abstract calcite moonmilk which is a cave deposit formed of calcite crystals and water is found in many caves in the italian alps these modern and ancient deposits are formed of fiber calcite crystals 50 500 nm wide and 1 to 10 m long and polycrystalline chains that have few crystal defects radiocarbon dating indicates that most moonmilk deposits in these caves are fossil and that for most precipitation ceased 6400 cal years bp at the end of the mid holocene hypsithermal in the caves of the italian alps the optimal conditions for formation of calcite moonmilk are 1 a temperature range of 3 5 5 5 c 2 low discharge volumes of seepage waters that are slightly supersaturated sical 0 0 to 0 2 and 3 relative humidity that is at or close to 100 microbial activity apparently did not play an active role in the formation of the calcite moonmilk conditions for moonmilk formation are typically found in caves that are located beneath land surfaces which are soil covered and support a conifer forest precipitation of the fiber calcite crystals apparently involved very slow flow of slightly supersaturated fluids the fact that moonmilk appears to form under a narrow range of environmental conditions means that this cave deposit has potential as a paleoclimatic indicator in high alpine karst areas

characterisation of post depositional taphonomic processes in the accumulation of mammals in a pitfall cave deposit from southeastern australia mceachern s deathtrap cave g49 50 is a classic pitfall trap located in southeastern australia which has been collecting terrestrial animals since the late quaternary dispersal and breakage of fossil bone elements are recognised as dominant taphonomic processes the sedimentary sequence contained within the cave consists of an upper and lower sequence where two distinct types of bone modification are identified the degree of bone breakage gradually increases with depth and is attributed to sediment compression and trampling minor in situ breakage has occurred as a result of rock fall and or trampling bone dispersal processes are indicated by a deficit in element representation required to account for whole skeletons based on mni calculations bone elements that are easily transportable by flowing water have a low frequency of representation in the sedimentary sequence in the cave floor bone lag deposit shallow intermittent flowing water is suggested by the dominance of transverse limb orientations and the low frequency of stable orientations that only occur in the most sensitive flow indicators e g pelves

reconstructing taphonomic histories using histological analysis abstract recent years have seen rapid advances in the understanding of diagenetic changes to bone tissues and how these influence the chemistry microstructure and histological appearance of ancient bone it is now possible to recognise many characteristic features of diagenetically modified bone and this has led to the potential use of these parameters in estimating the potential survival of biogenic signals such as dna lipids proteins and stable isotopes these characteristic features also hold the potential for preserving a record of different post mortem environments in individual bones or assemblages of bones from the same site in sites where the burial conditions have changed over archaeological or geological timescales histological analyses can shed light on these different burial environments and permit the reconstruction of taphonomic histories of some bones examination of polished sections of bone using bse sem has been used to identify characteristic features attributed to aerobic soil bacteria cyanobacteria and sulphate reducing bacteria the approach shows promise for providing supplementary evidence when phasing complex sites such as graveyards which developed over several hundred years

patterns of diagenesis in bone i the effects of site environments abstract we have measured a suite of diagenetic parameters for several populations of archaeological bones buried in a number of northwest european sites since the last ice age these are the structural damage due to microbes changes in bone micro and macro porosity protein content a measure of the crystallinity of hydroxyapatite as reflected in the phosphate infra red spectrum peak splitting and a measure of the carbonate content as given by the ratio of carbonate to phosphate infra red absorption peaks the results provide a database that clearly characterises the patterns which are often site dependent of diagenetic change in buried bone our main conclusions are that individual site hydrology appears to have a strong influence on the outcome of bone preservation and that porosity is the most effective single diagenetic parameter which both determines and reflects the preservation of bone in the burial environment

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

bone preservation in hayonim cave israel a macroscopic and mineralogical study abstract understanding the cause of patchy bone distributions in archaeological sites requires that one distinguish bone decomposition in place from empty areas where bones were never present marked horizontal variations in bone abundance are found in the thick mousterian layer e of hayonim cave a large paleolithic site in northern israel infra red analyses of minerals in the sediments identify zones of advanced diagenesis and decomposition alongside zones whose chemistry clearly favoured the preservation of bones and wood ash these differences adhere closely to the distribution of recognizable bones in the deposits indicating that spatial variation in bone abundance is essentially a product of differential preservation conditions however the few bones present in the bone poor units are in surprisingly good condition the higher degree of abrasion damage and more random orientations of these bones indicate that small amounts of recent material were introduced into older layers by small burrowing animals and perhaps localized trampling the ratio of post mousterian to mousterian artifacts in layer e and the numeric contrasts in bone abundance among stratigraphic units indicate that time averaging from mechanical intrusion was quantitatively unimportant 2 5 throughout this 2 4 m thick layer our findings support karkanas et al 2000 suggestion that bone and ash mineral diagenesis in caves follow step wise rather than gradual transformations in geological time good preservation environments can be distinguished from poorer ones on the basis of mineral assemblages in sediments and deposits that once contained bone and wood ash can be identified long after the visible traces of these materials have disappeared

nanomechanical properties of modern and fossil bone abstract relatively little is known about how diagenetic processes affect the mechanical properties of mineralized tissues such as vertebrate bones diagenesis can involve the alteration of bone s organic phase mineral phase and structural organization all of which contribute to bone s nanomechanical properties nanoindentation allows submicrometer investigation of alterations in bone properties that occur during diagenesis in this preliminary study the nanomechanical properties modulus and hardness of recent and fossil bone were compared through the use of depth sensing nanoindentation additionally x ray diffraction and density measurements were used to investigate changes in the mineral phase nanoindentation revealed that the basic mechanical anisotropy of modern bone can be preserved in fossil bones going back at least to the early eocene 50 ma as the elastic modulus i e stiffness values measured perpendicular to the long axis of each bone sample were consistently lower than longitudinal values as is the case for modern bones while a general increase in mechanical properties was observed with the geological age of the samples a relatively small increase was seen in fossil bone samples older than the miocene suggesting that mineral infilling is limited by spatial saturation as the modulus approached that of fully dense minerals such as quartz or apatite further evidence for modification of the mineral phase was demonstrated by an increase in crystallinity and density with the geological age of the bone both increased crystallinity and density correlated with increased modulus values suggesting that the size and perfection of the bioapatite crystals contribute to the mechanical properties of the bones rather unexpectedly the early oligocene aged bones demonstrated reduced modulus and hardness values compared to the miocene and eocene samples which we hypothesize to be related to the diagenetic environment specifically the fossil bearing strata at the oligocene aged locality contain volcanic ash which is known to dissolve bone mineral a plausible cause for the decreased mechanical properties of the oligocene bones our study demonstrates that nanoindentation a relatively nondestructive tool is useful in investigating tissue level diagenesis in bone that cannot be seen with the naked eye and can provide insight into the functional significance of mineralized tissues even after diagenesis has occurred

intra skeletal variability in trace elemental content of precolumbian chupicuaro human bones the record of post mortem alteration and a tool for palaeodietary reconstruction this study applies an intra skeletal sampling strategy to examine post mortem alteration of archaeological human bone from west mexico and to reconstruct ancient diet human bone from the chupicuaro culture mexico preclassic period constitutes an ideal material with which to examine subsistence strategies because the specific hydrothermal environment in which the population lived would have provided certain food components hydrothermal waters and carbonates with distinct signature in ca mg f li sr mn v and u values four to ten samples were taken from the long bones of six skeletons bone trace element content ca p f mn mg na li v zn rb sr ba y la ce nd th u and bone alteration parameters crystallinity organic matter and secondary calcite content were analysed at the intra skeletal level stable isotopic signatures bone d13c and d18ocarbonate and histological analyses were also performed on a single bone from each individual results indicate that all of the skeletons were affected by post mortem mineralogical structural and geochemical transformations biological bone d13c values seem preserved for most of the individuals but an increase in crystallinity accompanies depletion in bone d18o values the combination of bone alteration parameters with bone elemental content shows that in this very specific context a widespread dissolution recrystallisation is unlikely of the hydrothermal tracers sr f and li were of particular interest because their retention in living tissues is related to the amount ingested the intra skeletal li content does not reveal any pattern but li depletion is not excluded in contrast sr and f show a progressive intra skeletal diagenetic enrichment likely due to gradual diffusioneadsorption processes the bones with the lowest concentrations in these elements are assumed to yield the best representative ante mortem values the signal extracted from each skeleton a very unusually high bone sr f and li content is interpreted as reflecting the consumption of the local hydrothermal products which are also enriched in these elements

variability of bone preservation in a confined environment the case of the catacomb of sts peter and marcellinus rome italy most of the studies investigating the diagenetic trajectory of fossil bones focus on open air sites and very little work have been published in confined environments such as catacombs while the stable thermal history of catacombs should favor bone preservation the accumulation of corpses over a short period of time could favor their destruction the aim of this study is to describe the diagenetic trajectory of 128 human bone samples coming from six different burial chambers of the catacomb of sts peter and marcellinus sspm rome italy a multi proxy approach was undertaken to provide an assessment of the molecular preservation as well as a direct record of the isotopic composition itself collagen yield carbon and nitrogen abundances c n ratio ft ir based collagen and carbonate contents and crystallinity index radiocarbon dating and stable isotope analysis of bone collagen and carbonate indicate that both the mineral and the organic fractions are impacted by diagenesis to various degrees and that bones originating from the small burial chambers are more affected than those coming from the large ones while some of the bones were strongly recrystallized the impact of bone diagenesis on the stable isotope values of bone carbonate was limited comparison with contemporary sites from the latium showed that conditions prevailing in catacombs seem overall to favor rather than disadvantage bone preservation

how to obtain earthquake ground motions for engineering design abstract the earthquake ground motions that ultimately are selected for engineering design depend chiefly on the criticality of a site or structure and the engineering analyses that are to be performed several key steps are necessary in this selection process they are 1 a reconnaissance to understand the hazards and obtain preliminary earthquake ground motions 2 decisions on the application of deterministic or probabilistic methods 3 selection of appropriate motions for requirements in design 4 consideration of thresholds at which motions become significant for engineering and 5 decisions on specifying appropriate earthquake ground motions for sizes of earthquakes distances from sources the structures sites and testing to be done this paper presents five tables that show steps for evaluating these factors and for enabling the investigator to specify earthquake ground motions appropriate for engineering design

chemical compositional changes in archaeological human bones due to diagenesis type of bone vs soil environment abstract diagenesis in human remains is a subject of growing interest due to the increase in bone chemical studies to reconstruct pre and post mortem features in archaeological and forensic sciences the efforts made during the last decades have solidified our understanding of diagenetic processes however their high complexity demands more research to address them empirically specifically considering factors such as types of soil substratum and skeletal element in this work a geochemical study of human remains from the archaeological site of a lanzada nw spain is performed to understand diagenesis i e chemical alteration and life environmental exposure three types of bone thoracic long and cranial from 30 skeletons of two periods 9 roman 21 post roman were analysed by x ray fluorescence bones were recovered from burials located in slightly alkaline haplic arenosol calcaric and acidic cambic umbrisol humic soils principal components analysis was applied to extract the main chemical signatures and analysis of variance to determine the influence of different factors bone composition was characterized by four chemical signals related to i alteration of bone bioapatite ii metal sorption from the soil solution iii presence of fine silt clay soil particles and iv lead incorporation thoracic bones were found to be more sensitive to diagenesis and the burial environment long bones and crania presented a similar response skeletons buried in the acidic soil were significantly poorly preserved lead content was higher in bones of the roman period which seems to be related to pre mortem conditions previous investigations on palaeopollution in nw spain enable us to hypothesize that roman individuals may have been subjected to a high exposure of pb due to elevated atmospheric metal contamination

bone and enamel carbonate diagenesis a radiocarbon prospective abstract the debate regarding the susceptibility of bone and enamel carbonate to preserve in vivo carbon isotope ratios is as old as paleodietary research after more than three decades of controversy a consensus seems to have been reached and archeological bone apatite is generally considered suitable while enamel has become the gold standard for pre quaternary studies but the absence of a quantitative diagenetic test to assess the preservation of bone and enamel carbonate 13c values is problematic here radiocarbon 14c dating is used as a tracer to quantify carbon isotope exchange in bone dentine and enamel carbonate during early diagenesis samples covering most of the range of radiocarbon dating and coming from different burial environments and climates were dated when possible enamel dentine and bone from the same individuals were selected all tissues record an uptake of modern carbon leading to a change in the radiocarbon age of the sample which becomes significant after about 8000 bp in some of the sites enamel is older than bone or dentine carbonate from the same individual while in others the contrary is observed an intermediate case where identical 14c ages were measured between bone carbonate and enamel was also observed suggesting either a lack of alteration or similar degree of c isotope exchange for the two tissues overall no systematic 14c difference was found between bone dentine and enamel from the same individual suggesting that differences in crystallinity or porosity do not play a major role during the early stage of bone and enamel diagenesis and that 13c values measured in bone apatite are as reliable as in enamel at least for the past 40 000 yr

individual faults can t produce a gutenberg richter earthquake recurrence abstract individual faults within a region cannot have a gutenberg richter recurrence if the total of earthquakes within the region follow a gutenberg richter recurrence few faults have produced and adequate number of earthquakes to establish the nature of recurrence on them broad seismic regions however for which there is a statistically viable earthquake data set have been shown to obey a gutenberg richter recurrence with a slope of about 1 a gutenberg richter recurrence is often assumed for faults in probabilistic seismic hazard analyses the requirement that individual faults cannot produce earthquakes with this recurrence casts doubt on the validity of such probabilistic methods errors in probabilistic seismic hazard analysis tend to be amplified in the calculation of rare earthquake probabilities and it is these rare earthquakes for which critical facilities must be designed therefore sole use of probabilistic seismic hazard analysis for critical facilities is not recommended

sediments of biśnik cave poland lithology and stratigraphy of the middle palaeolithic site abstract bi nik cave is an important palaeolithic site located in the krakow czestochowa upland the cave fill is a complex well stratified sequence composed of 35 layers sublayers interrupted by number of hiatuses and ranging from pliocene till modern times fifteen middle palaeolithic horizons some of them among the oldest in poland represent the most important part of the sequence from an archaeological point of view the sedimentary sequences in particular parts of the cave have been studied for more than 20 years to investigate the chronostratigraphy and palaeoenvironment the recent multi proxy study is based on the application of new methods for the site analysis of sedimentary and post sedimentary structures and weathering stage of limestone rubble and fossil bones pollen analysis molecular biomarkers palaeomagnetic analysis and radiometric dating results indicated a more intensive role of re working and re deposition in the cave older sediments were transported into some stratigraphic horizons from sources within the cave itself as well as from outside including palaeontological and archaeological materials some the detected layers therefore represent a mix derived from different sources a record of two interglacials eemian interglacial mis 5e and penultimate interglacial mis 7 was established in layers nos 15 14 13a 13 and 19a 19 respectively middle upper pleistocene sedimentary units were identified with mis 3 mis 7 8 instead of previous interpretation to mis 4 mis 9 the age of the basal vario colored complex previously interpreted mostly as pre pleistocene was newly correlated with mis 7 8 and early pleistocene pliocene

diagenetic changes on bone histology of quaternary mammals from a tropical cave deposit in southeastern brazil abstract karst caves are suitable environments for the accumulation and preservation of fossils cave deposits are often complex and the environmental conditions within cave sites result from intricate interactions between various biological physical and chemical factors however it is not fully understood how the complexity of the environmental conditions of caves influences bone diagenesis the study of the initial stages of bone diagenesis depends to a large extent on understanding the changes in the bone histology to contribute to this issue we examine a set of postmortem changes affecting the bone histology of quaternary mammals that accumulated naturally in locus 2 a pitfall site in cuvieri cave located in the tropical region of brazil our analyses show that bones deposited in caves may be subject to a peculiar set of environmental conditions that in tropical regions may prevent the preservation of bone histological structure the effect of diagenetic processes on the bones differs depending on the taphonomic stage of the bone and the diagenetic alterations appear to have influenced each other the deposition of bioclasts following the entrapment of individuals in locus 2 favours the proliferation of bacteria on bones and appears to be important in directing the diagenetic alteration the hydrological regime of the cave that is recharge with potential phases of higher humidity also is important in directing the diagenetic alteration and further decreased the preservation potential of the bone microstructure the formation of macroscopic and microscopic cracks related to bone weathering in caves shows that the taphonomic processes peculiar to these environments are poorly understood highlighting the need for more research to be conducted on cave taphonomy

light at the end of the tunnels the origins of microbial bioerosion in mineralised collagen abstract microbial bioerosion in all its manifestations is one of the major factors determining the long term survival of archaeologically and environmentally important artefacts and ecofacts made from mineralised collagen bones antler teeth and ivory the bone diagenesis literature contains extensive descriptions of different morphologies and classifications of microbial bioerosion microscopical focal destruction wedl tunnels linear longitudinal budded and lamellate tunnelling etc but the causative agents remain to be discovered palaeontologists are in a similar situation when describing ichnofossils where bioerosion is classified by its characteristic morphology and only tentatively assigned to specific causes in archaeological bones wedl tunnels have traditionally been ascribed to fungi but a re examination of wedl s original paper and subsequent literature has shown that all the early specimens examined came from aquatic environments and that euendolithic microflora cyanobacteria or chlorophytes might have been responsible these microorganisms are known to tunnel into marine shells linear longitudinal budded and lamellate tunnelling have all been ascribed to bacteria however analyses using a combination of backscatter sem bsem and mercury intrusion porosimetry hgip of bones excavated from terrestrial soils suggest that the various tunnelling morphologies described by earlier researchers are actually all manifestations of a single architecture the differences arising from the inherent variability of bone microstructure and the hydrology of the burial environment an examination of the bsem and hgip data also indicates that the bacteria responsible may spread through dead bone tissues by expanding the canalicular network or dentinal tubules in teeth rather than creating new tunnels long term field burial experiments using de fleshed cow bone specimens have now demonstrated that bacterial tunnelling develops over decades rather than months as was previously thought even in warm tropical soils this has obvious implications for the origin of the bacteria responsible soil bacteria versus endogenous gut bacteria since the bone specimens were quickly isolated from gut contents although no attempt is made here to identify a specific organism or organisms responsible for tunnelling in terrestrial archaeological bones a tentative model is proposed for how cycles of wetting and drying or changes in local dissolved oxygen levels could lead a common gram positive soil bacterium to produce the pattern of bacterial bioerosion seen in exhumed bones this soil organism may act in a similar way to staphylococcus aureus which proliferates in living bone causing osteomyelitis by infiltrating and enlarging the canalicular network

age and tectonic setting of volcanic rocks of the tamulangou formation in the great xing an range ne china abstract zircon u pb chronological and geochemical research has been undertaken on the volcanic rocks of the tamulangou formation in the zhalantun area middle part of the great xing an range in ne china the volcanic rocks yield ages of 147 ma the late jurassic 14 17 myr younger than volcanic rocks of the same formation in the northern part of the great xing an range indicating that volcanism spanned the middle late jurassic the tamulangou volcanic rocks together with the jixiangfeng formation and rhyolite of the shangkuli formation constitute bimodal volcanics related to widespread coeval a type granites suggesting the tamulangou formation volcanics formed in an extensional environment spatial variations in petrological geochronological and geochemical features of the volcanic rocks of the tamulangou formation indicate subduction to the southeast following orogenesis and closure of the mongol okhotsk ocean

bone diagenesis in the european holocene i patterns and mechanisms diagenetic changes in archaeological bone are known to influence the data derived from such material and have thus been the subject of numerous studies a number of general trends have been observed but many of the processes that occur are still not fully understood we present here the analysis of 195 bones excavated from 32 sites in five different countries from eurasia characterized using 10 simple diagenetic parameters the results reveal that most european holocene archaeological bone can be categorized by only four main diagenetic states related to three distinct trajectories that describe more than 60 of the variation in these parameters given the potential amount of variation in the dataset the small number of diagenetic pathways is surprising but highlights the large importance of a few key factors that influence bone diagenesis mercury intrusion porosimetry is a key technique for identifying modes of degradation

early cretaceous lower crustal reworking in ne china insights from geochronology and geochemistry of felsic igneous rocks from the great xing an range this paper presents new zircon la icp ms u pb ages and whole rock geochemical data for two granitic plutons and rhyolites of the baiyingaolao formation in the western xing an range ne china the two syenogranite granitic plutons yield identical zircon u pb age of 142 1 ma and the baiyingaolao rhyolites yield zircon u pb age of 138 2 ma the granites contain some hornblendes and show low zr and zr nb ce y contents and low a cnk 0 98 1 11 mg 6 55 and feot mgo values rhyolite samples show similar geochemical characteristics with a cnk of 0 99 1 10 and mg of 14 21 in combination with the high k2o contents 4 43 5 61 wt and negative correlations between p2o5 and sio2 both the granites and rhyolites were classified as high k calc alkaline i type granitoids all samples give high zirconium saturation temperature of 794 964 c with few initially inherited zircons and belong to high temperature i type granitoids they were generated by dehydration melting of biotite muscovite from sub alkaline meta basalts in lower crust depth leaving garnet amphibole and plagioclase as the major residual minerals the syenogranites and rhyolites are likely formed in mongol okhotsk oceanic subduction setting incorporating other lower crust originated felsic rocks in erguna and xing an massifs and songliao basin it is argued that lower crustal reworking is pronounced in ne china during early cretaceous

measurements and relationships of diagenetic alteration of bone from three archaeological sites four diagenetic parameters have been chosen to represent the state of diagenesis of bone buried on archaeological sites they are histological preservation protein content crystallinity and porosity how these parameters are measured is described and results from populations of bones from three different sites are presented the results show the extent and variation in the degree of change both within a site and between sites in particular the correlations between diagenetic parameters are examined which give clues about the processes which cause alteration the value of porosity determinations both at the intercrystalline level and at coarser levels in revealing the degree of diagenetic change in bone and in underlying the dynamics of the interaction between buried bone and the surrounding water is stressed the data also indicate but are too restricted to prove the following microbiological attack is generally complete within less than 500 years substantial levels of protein may remain in bone after maximal micromorphological alteration loss of protein appears to be independent of other diagenetic change the correlated lose of microporosity with increase of crystallinity suggests these changes may arise from the dissolution perhaps with subsequent recrystallization of the smallest hydroxyapatite crystallites

bone diagenesis variability among multiple burial phases at al khiday sudan investigated by atr ftir spectroscopy abstract in this study the diagenetic pathways of archaeological human bones are investigated through fourier transform infrared spectroscopy in attenuated total reflection mode atr ftir archaeological excavations at al khiday 16 d 4 site khartoum sudan revealed a multi stratified cemetery with distinct burial phases chronologically attributed to different periods spanning from the early holocene to the beginning of the 1st millennium ce atr ftir measurements are carried out on a set of 56 bone samples representative of each burial phase parameters related to collagen content and to bioapatite crystallinity and structural carbonate are calculated from infrared spectra in order to monitor the types and extent of diagenetic alteration to assess the preservation state of bones and to define the alteration processes occurring during burial a new method is here developed to quantify the amount of secondary calcite and to remove its contribution to the infrared spectrum when interfering with the signal of structural carbonate from bioapatite considering the wide span of time covered by the archaeological record the variability of bones alteration among burial phases is related to the climatic changes occurring in central sudan during the holocene the more humid environment occurring in the early holocene characterised by higher precipitation rates seasonal swamps and palaeo lakes progressively changed towards drier conditions until the current arid climate of the sub saharan belt the change of palaeoenvironmental and local burial conditions over time differently influenced the types and extent of diagenetic processes affecting bones during burial in this research are also discussed advantages and disadvantages of atr ftir spectroscopy with respect to the more established ftir spectroscopy in transmission mode

diagenesis of archaeological bone and tooth an understanding of the structural complexity of mineralised tissues is fundamental for exploration into the field of diagenesis here we review aspects of current and past research on bone and tooth diagenesis using the most comprehensive collection of literature on diagenesis to date environmental factors such as soil ph soil hydrology and ambient temperature which influence the preservation of skeletal tissues are assessed while the different diagenetic pathways such as microbial degradation loss of organics mineral changes and dna degradation are surveyed fluctuating water levels in and around the bone is the most harmful for preservation and lead to rapid skeletal destruction diagenetic mechanisms are found to work in conjunction with each other altering the biogenic composition of skeletal material this illustrates that researchers must examine multiple diagenetic pathways to fully understand the post mortem interactions of archaeological skeletal material and the burial environment

late mesozoic calc alkaline volcanism of post orogenic extension in the northern da hinggan mountains northeastern china abstract late mesozoic calc alkaline volcanism in the northern da hinggan mountains ndhm ne china exhibits geochemical and sr nd isotopic characteristics similar to those of cenozoic calc alkaline volcanism in the basin and range province usa whole rock k ar dating results show that these volcanic sequences were erupted during 138 116 ma composed of basaltic andesites trachyandesites group 1 hornblende andesites trachytes group 2 and rhyolite lavas group 3 they are characterized by low mgo contents 4 20 lile lree enrichment and significant nb ta depletion as well as a little depleted to slightly enriched nd and weakly enriched sr isotopic ratios group 1 initial 87sr 86sr 0 70502 0 70572 nd t 0 78 to 0 91 group 2 initial 87sr 86sr 0 70497 0 70518 nd t 0 86 to 1 26 group 3 initial 87sr 86sr 0 70510 0 70635 nd t 0 41 to 0 25 the systematic variations in major and trace elements homogeneous sr nd isotope data and temporal consistency among three volcanic groups indicate that they were derived from a similar mantle source metasomatized by fluids related to the closure of the paleo asian and or mongolia okhotsk oceans and were produced through different degrees of fractional crystallization of the primary melts group 1 basaltic rocks were formed through removal of olivine and pyroxene of the primary melts while group 2 trachytes which contain the lowest lree contents e g la 24 28 ppm and relatively less enriched sr and higher nd isotope ratios were generated after removal of a few percent of lree rich minerals such as hornblende clinopyroxene and apatite of melts like group 1 group 3 rhyolite lavas exhibiting the highest abundances of strongly incompatible elements such as rb and k moderate lree contents e g la 28 53 ppm as well as apparently negative eu and sr anomalies represent the final crystallized products following a plagioclase predominant fractionation of melts like group 2 the low mgo contents and evolved affinities of the volcanic rocks imply that beneath the ndhm there existed many crustal magma reservoirs throughout the eruption episodes in which mantle derived primary melts had experienced intense differentiation these facts in combination with the contemporaneous basin and range tectonic regime suggest that the extensive calc alkaline volcanism in the ndhm was attributed to post orogenic diffuse extension rather than either an upwelling mantle plume or mesozoic oceanic plate subduction

geodynamics of the western part of the mongolia okhotsk collisional belt trans baikal region russia and mongolia abstract after the western edge of the mongolian microcontinent joined the siberian continent in the region of central mongolia in the earliest permian these two continental blocks remained turned at an angle of about 120 with respect to each other and separated on greater extent of their present day boundary by an enormous gulf of the paleopacific called the mongolia okhotsk ocean closure of this ocean at the early middle jurassic boundary led to the complete collision of siberia and mongolia which by then had already become part of the mongolia north china continent this main collisional episode which lasted through the middle and late jurassic involved thrusting folding and magmatism and produced the mongolia okhotsk belt the onon island arc which was located in the mongolia okhotsk ocean was squeezed between the two major continents inasmuch as the third element the island arc was involved in the collision it is reasonable to distinguish two branches of the mongolia okhotsk suture these branches control the spatial distribution of gold mineralization in the trans baikal region on the southeastern periphery of siberia the crust thickened considerably after the collision and a plateau like uplift formed in the early cretaceous when compression ceased the collisional uplift collapsed and the thrusts were transformed into low angle normal faults the motions on which were responsible for the formation of rift basins and exhumation of metamorphic core complexes

bone diagenesis in arid environments an intra skeletal approach bone trace element content and isotopic composition are closely related to human nutrition the investigation of archaeological bone geochemistry can help us to better understand the relationship between past populations and their environment alongside cultural practices as inferred from dietary reconstruction however dietary in formation may be altered post mortem by diagenetic processes in soil in this study bone mineralogy ca p sec ondary minerals organic matter content and bone apatite crystallinity histology element content mg na f sr ba mn fe la ce and u and stable isotope composition 13cand 18o carbonate were investigated at the intra individual scale in order to understand the effects of diagenesis on skeletons buried in different saharo sahelian environments between 10 to 18 bone samples were taken from 4 neolithic skeletons excavated in the mauritanian dhar oualata and nema and in the daounas mali additionally the enamel of two third molar teeth was also analysed from each skeleton for comparison with bone the results show that the four skeletons buried in the same desert climate area all exhibited different degrees of diageneticmodification relatedto localtaphonomic conditions highly drainedand periodically flooded environments generated substantial bone bacterial damage low to moderate apatite crystallinity and secondary minerals in bone pores bone trace element content and isotopic composition were more diagenetically affected than in bones from skeletons buried in a drier environment which display little bioerosion high apatite crystallinity and the absence or late precipitation of secondary minerals in their bone pores intra skeletal variability of the geochemical composition and the comparison of geochemical data from bones and teeth enables the approximation of ante mortem bone trace element and stable isotope compositions using the best preserved bones from each skeleton

evolution of the solonker suture zone constraints from zircon u pb ages hf isotopic ratios and whole rock nd sr isotope compositions of subduction and collision related magmas and forearc sediments abstract the solonker zone in northern inner mongolia china is considered as the suture between the north china craton and the south mongolian microcontinent two magmatic belts are recognized along the suture zone a subduction related magmatic belt represented by the baolidao arc rocks and a younger collision related granite belt represented by the halatu granites we use zircon u pb ages zircon in situ hf isotopic analyses and whole rock nd sr isotopic data of the two magmatic belts and related forearc sediments the xilinhot metamorphic complex to constrain timing of the suturing and to discuss the petrogenesis of the magmatic rocks a gabbroic diorite bld 1 of the baolidao arc was dated at 310 5 ma by shrimp this sample shows an e nd t value of 2 5 and i sr of 0 7052 hf isotopic analyses on 25 zircons from the same sample show e hf t 5 4 to 11 5 another diorite sample xh 2 of the same arc from south of xilinhot displays even more depleted isotopic compositions with e nd t 5 6 and i sr 0 7037 the main population of zircons from this sample have highly variable and depleted hf isotopic compositions e hf t 0 18 3 the large variation in hf isotopic composition of zircons with largely the same crystallization age from a single pluton is explained by a mixing process between depleted mantle derived magma and continental crust in an active continental arc setting the halatu granite hlt 2 was dated at 234 7 ma by shrimp zircons from the granite also show a large variation of e hf t values 9 1 to 26 despite most samples having whole rock e hf t 2 the large variation in e hf t values suggests that the granite formed probably by partial melting of two source regions a dominant juvenile crust and a subordinate old continental crust most zircons from the xilinhot metamorphic complex show ages comparable with those of the baolidao arc rocks suggesting that the protolith of the metamorphic complex was probably deposited during or after arc magmatism some zircons however show precambrian ages that fall into two groups one with ages of 780 900 ma resembling those from the south mongolian microcontinent and the other with ages of 1524 2900 ma similar to those of the north china craton thus the protolith of the metamorphic complex probably formed in a forearc basin during convergence of the two continents and metamorphosed subsequently during collision in the late paleozoic our zircon age data thus constrain timing of collision between the south mongolian microcontinent and the north china craton to have been between 296 and 234 ma

what drove late mesozoic extension of the northern china mongolia tract the northern china mongolia tract exhibited a tectonic transition from contractional to extensional deformation in late mesozoic time late middle to early late jurassic crustal shortening is widely thought to have resulted from collision of an amalgamated north china mongolia block and the siberian plate but widespread late late jurassic early cretaceous extension has not been satisfactorily explained by existing models some prominent features of the extensional tectonics of the northern china mongolia tract are 1 late jurassic voluminous volcanism prior to early cretaceous large magnitude rapid extension 2 overlapping in time of contractional deformation in the yinshan yanshan belt with development of extensionrelated basins in the interior of the northern china mongolia tract and 3 widespread occurrence of alkali granitic plutonism extensional basins and metamorphic core complexes in the early cretaceous a new explanation is advanced in this study for this sequence of events the collision of amalgamated north china mongolia with siberia led to crustal overthickening of the northern china mongolia tract and formation of a high standing plateau subsequent breakoff at depth of the north dipping mongol okhotsk oceanic slab is suggested as the main trigger for late mesozoic lithospheric extension of that tract slab breakoff resulted in mantle lithospheric stretching of the adjacent northern china mongolia tract with subsequent ascent of hot asthenosphere and magmatic underplating at the base of the crust collectively these phenomena triggered gravitational collapse of the previously thickened crust leading to late late jurassic early cretaceous crustal extension and importantly coeval contraction along the southern margin of the plateau in the yinshan yanshan belt the proposed model provides a framework for interpreting the spatial and temporal relationships of distinct processes and reconciling some seemingly contradictory phenomena such as the synchronous extension of northerly terranes during major contraction in the neighboring yanshan yinshan belt d 2003 elsevier b v all rights reserved

on porosity of archeological bones ii textural characterization of mesoamerican human bones abstract human bone porosity may be an indicator of many bone diseases but it can also reflect the influence of postmortem alterations the usually reported values for textural parameters such as specific surface area or porosity of archeological bones are not consistent as pathology and taphonomy may alter bone morphology at nano and or micrometrical levels to illustrate those points four archeological human bones were chosen they differ in the environment where they were found and on their attributed diseases complementary analysis techniques commonly mentioned in material science were used to characterize the chosen samples gas adsorption small angle x ray scattering and scanning electron microscopy it is shown that even if the differences between human pathological and healthy bones can be clear in fresh materials such alterations may be masked by taphonomy in archeological bones

bone diagenesis new data from infrared spectroscopy and x ray diffraction abstract this paper combines non destructive high resolution fourier transform infrared spectroscopic techniques attenuated total reflectance in the mid infrared atr and diffuse reflectance in the near infrared nir with x ray diffraction and rietveld analysis in the study of bone diagenesis sixty fossil bones from two upper miocene sites in greece pikermi and chalkoutsi and one upper pleistocene site in cyprus aghia napa are investigated in comparison to various mineral and biological apatites diagenetic trends common to all these sites include a subtle but systematic decrease of the unit cell volume and a axis of carbonate hydroxylapatite as well as a parallel increase of the coherence length along the c axis chemometric modelling reveals that the changes in the unit cell and the coherence length are highly correlated to and can be predicted on the basis of the atr spectra besides using chemometrics as a convenient predictive tool we have been able to identify that the correlation with the xrd data is primarily based on the intensity of infrared bands at 577 865 and 1092 cm 1 as well as on the position of the 1 phosphate mode at ca 960 cm 1 these structural changes constitute the vibrational signature of diagenesis throughout our set of bone samples and can be accounted for by the stabilization of a distorted co 3 2 species in the b sites of apatite and to a lesser extent by the substitution of oh by f nir spectroscopy allowed for the identification of a well defined h 2 o species absorbing at 5318 and 7240 cm 1 this species is labile appears to characterize mostly biogenic apatite and is therefore considered to be chemisorbed on the surface of the crystallites

geochronology and geochemistry of the wunugetushan porphyry cu mo deposit in ne china and their geological significance abstract the wunugetushan porphyry cu mo deposit is located in the manzhouli district of ne china on the southern margin of the mesozoic mongol okhotsk orogenic belt concentric rings of hydrothermal alteration and cu mo mineralization surround an early middle jurassic monzogranitic porphyry the cu mo mineralization is clearly related to the quartz potassic and quartz sericite alteration molybdenite re os and groundmass 40 ar 39 ar of the host porphyry dates indicate that the ore formation and porphyry emplacement occurred at 177 6 4 5 ma and 179 0 1 9 ma respectively geochemically the host porphyry of the deposit is characterized by strong lree hree fractionation enrichment in lile ba rb u th and pb and depletion of hfse nb ta ti and hree the sr nd pb isotopic compositions of the porphyry display an varied initial 87 sr 86 sr i ratio a positive e nd t values and high 206 pb 204 pb t 207 pb 204 pb t and 208 pb 204 pb t ratios these data indicate that the magmatic source of the host porphyry comprised two end members lithospheric mantle metasomatized by fluids derived from the subducted slab and continental crust we infer that the primitive magma of the host porphyry was derived from crust mantle transition zone based on regional geology and geochemistry of the host porphyry the wunugetushan deposit is suggested to form in a continental collision environment after closure of the mongol okhotsk ocean

spatial temporal relationships of mesozoic volcanic rocks in ne china constraints on tectonic overprinting and transformations between multiple tectonic regimes abstract la icp ms zircon u pb ages and geochemical data are presented for the mesozoic volcanic rocks in northeast china with the aim of determining the tectonic settings of the volcanism and constraining the timing of the overprinting and transformations between the paleo asian ocean mongol okhotsk and circum pacific tectonic regimes the new ages together with other available age data from the literature indicate that mesozoic volcanism in ne china can be subdivided into six episodes late triassic 228 201 ma early middle jurassic 190 173 ma middle late jurassic 166 155 ma early early cretaceous 145 138 ma late early cretaceous 133 106 ma and late cretaceous 97 88 ma the late triassic volcanic rocks occur in the lesser xing an zhangguangcai ranges where the volcanic rocks are bimodal and in the eastern heilongjiang jilin provinces where the volcanics are a type rhyolites implying that they formed in an extensional environment after the final closure of the paleo asian ocean the early middle jurassic 190 173 ma volcanic rocks both in the erguna massif and the eastern heilongjiang jilin provinces belong chemically to the calc alkaline series implying an active continental margin setting the volcanics in the erguna massif are related to the subduction of the mongol okhotsk oceanic plate beneath the massif and those in the eastern jilin heilongjiang provinces are related to the subduction of the paleo pacific plate beneath the eurasian continent the coeval bimodal volcanic rocks in the lesser xing an zhangguangcai ranges were probably formed under an extensional environment similar to a backarc setting of double direction subduction volcanic rocks of middle late jurassic 155 166 ma and early early cretaceous 145 138 ma age only occur in the great xing an range and the northern hebei and western liaoning provinces limited to the west of the songliao basin and they belong chemically to high k calc alkaline series and a type rhyolites respectively combined with the regional unconformity and thrust structures in the northern hebei and western liaoning provinces we conclude that these volcanics formed during a collapse or delamination of a thickened continental crust related to the evolution of the mongol okhotsk suture belt the late early cretaceous volcanic rocks widely distributed in ne china belong chemically to a low to medium k calc alkaline series in the eastern heilongjiang jilin provinces i e the eurasian continental margin and to a bimodal volcanic rock association within both the songliao basin and the great xing an range the volcanics in the eastern heilongjiang jilin provinces formed in an active continental margin setting related to the subduction of the paleo pacific plate beneath the eurasian continent and the bimodal volcanics formed under an extensional environment related either to a backarc setting or to delamination of a thickened crust or both late cretaceous volcanics limited to the eastern heilongjiang jilin provinces and the eastern north china craton ncc consist of calc alkaline rocks in the eastern heilongjiang jilin provinces and alkaline basalts in the eastern ncc suggesting that the former originated during subduction of the paleo pacific plate beneath the eurasian continent whereas the latter formed in an extensional environment similar to a backarc setting taking all this into account we conclude that 1 the transformation from the paleo asian ocean regime to the circum pacific tectonic regime happened during the late triassic to early jurassic 2 the effect of the mongol okhotsk suture belt on ne china was mainly in the early jurassic middle late jurassic and early early cretaceous and 3 the late early cretaceous and late cretaceous volcanics can be attributed to the subduction of the paleo pacific plate beneath the eurasian continent

bone diagenesis at the micro scale bone alteration patterns during multiple burial phases at al khiday khartoum sudan between the early holocene and the ii century ad abstract histological analysis is widely applied to archaeological and fossil bones in order to identify diagenetic changes in bone microstructure diagenetic processes affecting bones from the body deposition to the discovery strongly depend on environmental conditions therefore the study of diagenetic alterations provides valuable information on the taphonomic history of bones and on their burial environment histological analysis was performed on 58 samples of human compact bone found at al khiday khartoum sudan a multi stratified archaeological site that revealed a cemetery with distinct burial phases dating from the early holocene to the ii century ad the well defined archaeological context provides a set of bone samples belonging to the same site but buried in different phases and under different environmental conditions central sudan was characterised by a humid environment with seasonal swamps and palaeo lakes in the early holocene while in the ii century ad the environmental conditions were more similar to the current arid climate of the sub saharan belt scanning electron microscopy sem and high resolution x ray computed micro tomography ct analysis revealed extensive bacterial and fungal attack and secondary phases precipitation and dissolution in the samples the analysis of textural relationships between each diagenetic feature enabled to establish a relative chronological sequence of events acting during burial moreover different patterns of diagenetic alterations were observed for burial phases of different ages proving a strong relationship between diagenesis and environmental conditions

patterns of diagenesis in bone ii effects of acetic acid treatment and the removal of diagenetic co32 abstract archaeological bones of varying preservation have been treated with 0 1 m acetic acid in order to investigate the effect on structural and chemical alterations caused by diagenesis acetic acid is commonly used as a cleaning agent for removing diagenetic carbonate from bone and enamel in an attempt to recover original biogenic signals for use in dietary and14c dating studies diagenetic parameters were measured before and after treatment on a range of archaeological bones with good and bad preservation histological preservation defined the behaviour of the correlating parameters where correlation coefficients between carbonate content and crystallinity microporosity and macroporosity increased significantly after treatment for histologically well preserved material acetic acid is effective at returning carbonate content to around that of modern bone where bone is extensively damaged by micro organisms loose diagenetic material can be removed but a fraction largely composed of hypermineralized bioapatite remains which we believe cannot be reliably used to obtain accurate biological signals

an evaluation of nitrogen porosimetry as a technique for predicting taphonomic durability in animal bone to date direct measurements of bone porosity have been used primarily to quantify the degree of diagenetic alteration qualitative zooarchaeological observations over many years have suggested that for equivalent burial conditions the bones of different taxa degrade at different rates and that even within a single skeleton systematic variation often occurs given that freedom of access of water to the internal bone surface is likely to be an important factor in controlling the rate of chemical alteration we postulate that the initial porosity of a bone may be an important factor in predicting the rate of degradation to test this we have used nitrogen porosimetry as a technique for comparing the total pore volume and size distribution of pores between a selection of anatomical elements taken from a range of modern animals commonly represented on european archaeological sites we show that the bones of modern domestic pig are on average more porous than those of other ungulates and should therefore be likely to degrade faster after burial systematic differences in porosity are also shown between different anatomical elements from a single individual and between adult and juvenile bone however we also show that porosity measurements are affected by sample storage and preparation methodology particularly freezing variations in bone porosity between different skeletal elements and taxa necessitate careful sample selection and matching in order to minimize variation we conclude that despite these restrictions direct measurement of variations in bone porosity shows good potential for contributing to a predictive model for bone diagenesis

microbial attack of archaeological bones versus high concentrations of heavy metals in the burial environment a case study of animal bones from a mediaeval copper workshop in paris abstract microbial attack is one of the key processes altering archaeological bone during the early stage of diagenesis some burial conditions seem more prone to prevent microbial attack in archaeological bone it is generally admitted that the presence of certain metals in the burial environment such as copper may have an inhibiting effect on microbial destruction of archaeological bone this study was aimed at evidencing such effects by the investigation of different archaeological animal bones excavated from several activity zones of one french archaeological urban site corresponding to a mediaeval copper alloys workshop in paris at hotel de mongelas the analytical approach combined morphological observations sem structural investigations ft ir xrd and tem and chemical analyses sem edx and pixe pige of archaeological bones at different scales down to the nanoscale it permitted the classification of the bones as a function of their contamination with heavy metals their conservation state and the presence of signs of microbial attack correlations between the observed alteration features and the metallurgical activity on this site as well as the underlying alteration processes are discussed an inhibiting effect of heavy metals on the microbial attack could be deduced from the available though restricted data in agreement with the expectation however the relationship between heavy metal uptake and microbial alteration of bone depends on other diagenetic factors and their progress such as bone collagen content crystallinity of bone mineral soil geochemistry and hydrology significant changes in environmental conditions over time which can especially occur in urban sites can also influence alteration phenomena generally simultaneous alterations induced by heavy metal uptake and microbial attack seem to take place in the very early stage of diagenesis and influence one another in sites with soils highly contaminated in heavy metals

examining histology to identify burned bone abstract early research suggests that examination of the microscopic internal structure is a valid method for distinguishing burned from unburned bone in the archaeological record this study compares burned and unburned modern bones with archaeological bones from sibudu cave ca 60 000 years ago and cave of hearths over 200 000 years ago to more fully describe the heat induced histological changes to bone we also explore the effects of diagenesis on those changes to determine if histological evidence of burning preserves through fossilisation and diagenetic processes and can be successfully used to identify ancient burning application of this technique can help in addressing various issues including the origins of controlled use of fire and understanding animal butchery and disposal

the hulan group its role in the evolution of the central asian orogenic belt of ne china the hulan group of central jilin province northeastern ne china consists of felsic volcanic and sedimentary rocks that underwent sub greenschist to amphibolite facies metamorphism and multiple phases of deformation during formation of the central asian orogenic belt young nd model ages of 1100 ma obtained in this study do not support earlier models that the hulan group was either rifted from the north china craton to the south or from the jiamusi block to the north since both these blocks have much older nd model ages detrital zircon u pb ages from a meta sedimentary rock of the hulan group define a maximum age of deposition of 287 6 ma not early palaeozoic as previously believed rb sr mineral isochron data indicate that metamorphism of the hulan group occurred at 250 ma this conclusion is further supported by an age of 248 4 ma for the dayushan granite which intruded the hulan group these new isotopic data together with evaluation of the regional geology indicate that final oceanic closure in the chinese segment of the central asian orogenic belt took place in the late permian the hulan area is located along the solonker xra moronchangchun suture that extends from inner mongolia across to central jilin province it is this zone that marks the final ocean closure resulting in the amalgamation of the north china and siberian cratons 2007 elsevier ltd all rights reserved