evidence for increased latent heat transport during the cretaceous albian greenhouse warming quantitative estimates of increased heat transfer by atmospheric h2o vapor during the albian greenhouse warming suggest that the intensified hydrologic cycle played a greater role in warming high latitudes than at present and thus represents a viable alternative to oceanic heat transport sphaerosiderite d 18 o values in paleosols of the north american cretaceous western interior basin are a proxy for meteoric d 18 o values and massbalance modeling results suggest that albian precipitation rates exceeded modern rates at both mid and high latitudes comparison of modeled albian and modern precipitation minus evaporation values suggests amplification of the albian moisture deficit in the tropics and moisture surplus in the mid to high latitudes the tropical moisture deficit represents an average heat loss of 75 w m 2 at 108n paleolatitude at present 21 w m 2 the increased precipitation at higher latitudes implies an average heat gain of 83 w m 2 at 458n at present 23 w m 2 and of 19 w m 2 at 758n at present 4 w m 2 these estimates of increased poleward heat transfer by h2o vapor during the albian may help to explain the reduced equator to pole temperature gradients

meteoric sphaerosiderite lines and their use for paleohydrology and paleoclimatology sphaerosiderite a morphologically distinct millimeter scale spherulitic siderite feco 3 forms predominantly in wetland soils and sediments and is common in the geologic record ancient sphaerosiderites are found in paleosol horizons within coal bearing stratigraphic intervals and like their modern counterparts are interpreted as having formed in water saturated environments here we report on sphaerosiderites from four different stratigraphic units each of which has highly variable 13 c and relatively stable 18 o compositions the unique isotopic trends are analogous to well documented meteoric calcite lines which we define here as meteoric sphaerosiderite lines meteoric sphaerosiderite lines provide a new means of constraining ground water 18 o and thus allow evaluation of paleohydrology and paleoclimate in humid

estimating the oxygen isotopic composition of equatorial precipitation during the mid cretaceous abstract recent studies utilize the oxygen isotopic composition of pedogenic carbonates siderite and calcite to evaluate empirically the global hydrologic cycle during the cretaceous pedogenic carbonates are used as a proxy for the isotopic composition of meteoric waters in order to estimate precipitation rates in the aptian albian via a mass balance model these modeling studies have previously been limited to mid latitude to high latitude data and thus a more extensive latitudinal data set is needed to produce a more globally constrained model this study provides an equatorial 2 s paleolatitude data set from pedogenic sphaerosiderites of the caballos formation from the upper magdalena valley colombia in addition macroscopic and microscopic morphological features of paleosols were used to identify ancient soil conditions the gleyed appearance and presence of sphaerosiderites suggest that soils were dominated by water saturated conditions with occasional incursions of marine influenced water resulting in pyrite precipitation this observation constrains the sampling sites to paleoelevations near sea level paleosols are interpreted to have been entisols inceptisols and ultisols similar to soils in coastal equatorial regions of modern colombia relatively invariant 18o values and more variable 13c values produce vertical trends in 13c vs 18o space called meteoric sphaerosiderite lines the average oxygen isotopic composition for these trends is 4 41 0 37 vpdb the average oxygen isotopic composition of meteoric waters precipitating the sphaerosiderites is estimated at 4 56 0 38 vsmow these are slightly more enriched than modern and modeled cretaceous estimates of equatorial precipitation 18o but are generally in agreement with expected oxygen isotopic compositions of precipitation for this paleolatitude

analytical techniques for the separation and sem identification of heavy minerals in mudrocks heavy mineral investigations must be preceded by effective heavy mineral separation identification and determination of mineral compositions provenance determinations by heavy mineral variations and direct measurement of the control of trace elements by heavy minerals in mudrocks has not been possible because of the difficulties in separating heavy minerals from the obscuring mass of the clay matrix the technique to separate identify and determine the variability of heavy minerals in mudrocks presented here is nondestructive and works well with mudrocks of variable induration and maturation from mudstones to shales this methodology uses lithium metatungstate for heavy liquid separations of bulk samples and a combination of optical and scanning electron microscopy sem for identification and quantification of heavy mineral proportions

the northernmost and latest occurrence of the fossil porcupine hystrix brachyura vinogradovi argyropulo 1941 in the altai mountains in the late pleistocene ca 32 000 41 000 cal bp abstract several new finds of the late pleistocene porcupine hystrix brachyura vinogradovi in the altai mountains of southern siberia and the urals occur far north of previously assigned range for porcupine these finds have necessitated a renewed study of this species s chronology and spatial distribution we conclude that the oldest records of this porcupine in the ural mountains date to mis 5e and its geographic range possibly included also the altai at that time directly radiocarbon dated porcupine bones in the altai fall in mis 3 ca 32 000 41 000 cal bp it is the northernmost record of this species and the youngest find outside its current geographic range

constraints on palaeoenvironments in the lower cretaceous wealden of southern england from the geochemistry of sphaerosiderites abstract sphaerosiderites are millimetre scale concretions of feco 3 that form predominantly in waterlogged environments and are of use in palaeoenvironmental and palaeohydrological studies we present petrographic elemental and stable isotopic 13 c 18 o data from sphaerosiderites collected from the lower cretaceous wealden sediments of southern england the sphaerosiderites are composed of very pure feco 3 with only small amounts of ca mg and mn present suggesting that they are well preserved and were precipitated from fresh groundwater 13 c values display a relatively large range from about 5 to 30 vpdb in contrast 18 o values are relatively invariant 1 0 83 with an average of 3 01 vpdb the relationship between carbon and oxygen suggests that the sphaerosiderites faithfully record palaeo groundwater 18 o likely 18 o values for groundwater were calculated using a published experimentally derived siderite water fractionation equation and plausible assumed values for palaeotemperature the average estimate was 4 9 smow the wealden sphaerosiderite oxygen isotope values are comparable with other early cretaceous data from similar palaeolatitudes but lower than estimated holocene values for equivalent latitudes this observation may indicate greater rainfall at 30 n during the cretaceous relative to the holocene and also suggests relative stability of palaeoclimatic conditions during the early cretaceous at this palaeolatitude

middle to late pleistocene hominin occupation in the three gorges region south china the contributions of the chinese paleolithic record to broader ranging paleoanthropological debates have long been difficult to decipher the primary problem that hinders many contributions that include or focus on the chinese record is that relatively few regions outside of the main flagship sites basins e g zhoukoudian nihewan basin bose basin have been intensively researched fortunately systematic archaeological survey and excavations in the three gorges region south china over the past two decades has led to the discovery of a number of important hominin fossils and paleolithic stone artifact assemblages that have contributed to rethinking of ideas about hominin adaptations in pleistocene china this paper provides a detailed review of the results of recent paleoanthropological particularly paleolithic archaeological research from this region the three gorges region is located in the transitional zone between the upper and middle reaches of the yangtze river changjiang river vertebrate paleontological studies indicate that the faunas from this region belong primarily to the ailuropoda stegodon faunal complex a group of taxa representative of a subtropical forest environment systematic field surveys identified sixteen paleolithic sites in caves and along the fluvial terraces of the yangtze river based on geomorphology biostratigraphy and geochronology studies these sites were formed during the middle to late pleistocene follow up excavations at these sites led to the discovery of a large number of paleolithic stone artifacts pleistocene mammal fossils as well as some hominin fossils analysis of these materials has provided the opportunity to reconstruct hominin technological and mobility patterning in a restricted spatial point the paleolithic technology from the three gorges region is essentially an oldowan like industry i e mode 1 core and flake technologies comprised of casual cores whole flakes fragments and chunks as well as a low percentage of retouched pieces the utilized stone raw material is primarily high sphericity cobbles and limestone which were locally available along the ancient river bed and surrounding terraces most of the artifacts are fairly large in size all flaking is by direct hard hammer in a single direction without core preparation unifacial choppers are the predominant core category with fewer bifacial choppers sporadic discoids polyhedrons and bifaces the flake types demonstrate that the first stage of core reduction is represented by a low percentage of type iii and vi flakes some flakes are retouched unifacially by direct hard hammer percussion on the dorsal surface of the blanks archaic homo sapiens and modern h sapiens identified from some of the cave deposits are likely the hominins responsible for the production of the stone artifacts implications for oldowan like technological patterning in south china are discussed c 2012 elsevier ltd and inqua all rights reserved

the mid cretaceous water bearer isotope mass balance quantification of the albian hydrologic cycle a latitudinal gradient in meteoric n 18 o compositions compiled from paleosol sphaerosiderites throughout the cretaceous western interior basin kwib 34 75 n paleolatitude exhibits a steeper more depleted trend than modern predicted values 3 0x 34 n latitude to 9 7x 75 n lighter furthermore the sphaerosiderite meteoric n 18 o latitudinal gradient is significantly steeper and more depleted 5 8x 34 n to 13 8x 75 n lighter than a predicted gradient for the warm mid cretaceous using modern empirical temperature n 18 o precipitation relationships we have suggested that the steeper and more depleted relative to the modern theoretical gradient meteoric sphaerosiderite n 18 o latitudinal gradient resulted from increased air mass rainout effects in coastal areas of the kwib during the mid cretaceous the sphaerosiderite isotopic data have been used to constrain a mass balance model of the hydrologic cycle in the northern hemisphere and to quantify precipitation rates of the equable greenhouse albian stage in the kwib the mass balance model tracks the evolving isotopic composition of an air mass and its precipitation and is driven by latitudinal temperature gradients our simulations indicate that significant increases in albian precipitation 34 52 and evaporation fluxes 76 96 are required to reproduce the difference between modern and albian meteoric siderite n 18 o latitudinal gradients calculations of precipitation rates from model outputs suggest mid high latitude precipitation rates greatly exceeded modern rates 156 220 greater in mid latitudes 2600 3300 mm yr 99 greater at high latitudes 550 mm yr the calculated precipitation rates are significantly different from the precipitation rates predicted by some recent general circulation models gcms for the warm cretaceous particularly in the mid to high latitudes our mass balance model by no means replaces gcms however it is a simple and effective means of obtaining quantitative data regarding the mid cretaceous hydrologic cycle in the kwib our goal is to encourage the incorporation of isotopic tracers into gcm simulations of the midcretaceous and to show how our empirical data and mass balance model estimates help constrain the boundary conditions

the shuidonggou site complex new excavations and implications for the earliest late paleolithic in north china the initial late paleolithic said to appear between 40 and 30 kya in eastern asia is defined by the appearance of many innovations these archaeological indicators include the appearance of more refined stone tool making techniques e g include the appearance of blade and microblade technology complex hearth construction use of pigments and personal ornamentation as well as worked faunal implements such as bone and antler tools we report here new findings from a multidisciplinary research project conducted at the shuidonggou choei tong keou site complex in northern china a series of localities that date from the initial late paleolithic to the neolithic six new localities sdg7e12 were discovered and five localities sdg2 previously identified and sdg7e9 and 12 were excavated yielding more than 50 000 stone artifacts fauna ostrich eggshell beads and hearths dating results suggest that human occupation of the shuidonggou area occurred during the late pleistocene to middle holocene w32 000e6000 bp some sites are characterized by small irregular flakes casually retouched tools modified or informally retouched tools i e non standardized tools with sporadic retouch which was not well controlled and small numbers of blades or no blades others lithic assemblages are dominated by blades and microblades at two sites higher quality or exotic raw materials were exploited but at the majority of sites locally available river cobbles were used in addition to blades microblades and hearths more than 80 finely perforated and polished ostrich eggshell beads mostly colored with red ochre were recovered from three sites several worked bone needles and an awl were also uncovered from the youngest site sdg12 in deposits dating to c 13 000 cal bp the implications for the initial appearance of the late paleolithic in china and movement of modern human populations into north china are discussed

holocene survival of late pleistocene megafauna in china a critical review of the evidence late quaternary megafaunal extinction chronologies are poorly understood across eastern and southeast asia previous radiometric studies suggested that surprisingly many extinct late pleistocene large mammal species survived into the holocene in northern china bos primigenius coelodonta antiquitatis mammuthus primigenius and southern china ailuropoda baconi crocuta crocuta ultima megatapirus augustus stegodon orientalis sus cf xiaozhu indicating that chinese megafaunal extinctions may have been staggered across the late quaternary we critically re examined all radiometric evidence suggesting holocene survival of chinese late quaternary megafauna and conducted new dating of mammal material from reportedly holocene sites containing characteristically late pleistocene faunas evidence for holocene survival of any chinese late pleistocene megafaunal species is weak or untenable no previous radiometric dates used to support holocene megafaunal survival represent direct bone dates for species of interest and stratigraphic association between material yielding holocene dates and megafaunal remains is dubious at most sites concerns over accurate identification of faunal material further confuse claims for holocene survival of many species robust radiometric last occurrence dates for extinct chinese megafauna are all restricted to the late pleistocene similar to the timing of many other late quaternary megafaunal species extinctions elsewhere in eurasia and the americas c 2013 elsevier ltd all rights reserved

diagenetic overprinting of the sphaerosiderite palaeoclimate proxy are records of pedogenic groundwater delta18o values preserved meteoric sphaerosiderite lines msls defined by invariant d 18 o and variable d 13 c values are obtained from ancient wetland palaeosol sphaerosiderites millimetre scale feco3 nodules and are a stable isotope proxy record of terrestrial meteoric isotopic compositions the palaeoclimatic utility of sphaerosiderite has been well tested however diagenetically altered horizons that do not yield simple msls have been encountered well preserved sphaerosiderites typically exhibit smooth exteriors spherulitic crystalline microstructures and relatively pure 95 mol feco3 compositions diagenetically altered sphaerosiderites typically exhibit corroded margins replacement textures and increased crystal lattice substitution of ca 2 m g 2 and mn 2 for fe 2 examples of diagenetically altered cretaceous sphaerosideritebearing palaeosols from the dakota formation kansas the swan river formation saskatchewan and the success s2 formation saskatchewan were examined in this study to determine the extent to which original early diagenetic d 18 o and d 13 c values are preserved all three units contain poikilotopic calcite cements with significantly different d 18 o and d 13 c values from the co occurring sphaerosiderites the complete isolation of all carbonate phases is necessary to ensure that inadvertent physical mixing does not affect the isotopic analyses the dakota and swan river samples ultimately yield distinct msls for the sphaerosiderites and mcls meteoric calcite lines for the calcite cements the success s2 sample yields a covariant d 18 o vs d 13 c trend resulting from precipitation in pore fluids that were mixtures between meteoric and modified marine phreatic waters the calcite cements in the success s2 formation yield meteoric d 18 o and d 13 c values a stable isotope mass balance model was used to produce hyperbolic fluid mixing trends between meteoric and modified marine end member compositions modelled hyperbolic fluid mixing curves for the success s2 formation suggest precipitation from fluids that were 25 sea water

new fossil remains of elephas from the southern levant implications for the evolutionary history of the asian elephant abstract we describe new fossil remains of elephant elephas cf hysudricus from archaeological sites in the levant ma ayan baruch israel and ain soda jordan both sites date to the middle pleistocene based on stone artefacts typical of levantine late acheulian assemblages the elephant remains show primitive dental features reminiscent of e hysudricus from the plio pleistocene of the siwaliks northern india the species thought to be ancestral to asian elephant e maximus regionally the new fossils are chronologically intermediate between an earlier ca 1 ma record of elephas sp from evron quarry israel and holocene remains of e maximus from archaeological sites in nw syria turkey iraq and iran it is unclear at present whether this represents continuity of occupation or more plausibly independent westward expansions

a micromorphological record of contemporary and relict pedogenic processes in soils of the indo gangetic plains implications for mineral weathering provenance and climatic changes

high latitude meteoric δ18o compositions paleosol siderite in the middle cretaceous nanushuk formation north slope alaska siderite bearing pedogenic horizons of the nanushuk formation of the north slope alaska provide a critical high paleolatitude oxygen isotopic proxy record of paleoprecipitation supplying important empirical data needed for paleoclimatic reconstructions and models of greenhouse world precipitation rates siderite 18 o values were determined from four paleosol horizons in the national petroleum reserve alaska npr a grandstand 1 core and the values range between 17 6 and 14 3 peedee belemnite pdb with standard deviations generally less than 0 6 within individual horizons the 13 c values are much more variable ranging from 4 6 to 10 8 pdb a covariant 18 o versus 13 c trend in one horizon probably resulted from mixing between modified marine and meteoric phreatic fluids during siderite precipitation groundwater values calculated from siderite oxygen isotopic values and paleobotanical temperature estimates range from 23 0 to 19 5 standard mean ocean water smow minor element analyses show that the siderites are impure having enrichments in ca mg mn and sr minor element substitutions and mg fe and mg ca mg ratios also suggest the influence of marine fluids upon siderite precipitation the pedogenic horizons are characterized by gleyed colors rare root traces abundant siderite abundant organic matter rare clay and silty clay coatings and infillings some preservation of primary sedimentary stratification and a lack of ferruginous oxides and mottles the pedogenic features suggest that these were poorly drained reducing hydromorphic soils that developed in coal bearing delta plain facies and are similar to modern inceptisols model derived estimates of precipitation rates for the late albian of the north slope alaska 485 626 mm yr are consistent with precipitation rates necessary to maintain modern peat forming environments this information reinforces the mutual consistency between empirical paleotemperature estimates and isotope mass balance models of the hydrologic cycle and can be used in future global circulation modeling gcm experiments of greenhouse world climates to constrain high latitude precipitation rates in simulations of ancient worlds with decreased equator to pole temperature gradients

micromammals from an early holocene archaeological site in southwest china paleoenvironmental and taphonomic perspectives abstract investigations of the well known paleontological and archaeological site of tangzigou in western yunnan province in 2003 and 2006 yielded plentiful mammalian remains and a large number of stone and bone artifacts among the mammalian remains were those of many micromammals representing modern taxa of scandentia insectivora and rodentia the micromammal assemblage is dominated by rodents which constitute 92 of the total number of identifiable elements murids are the most common elements followed by rhizomyids sciurids and hystricids the tangzigou deposits appear to have been created over a period of 200 300 years in the early to middle holocene judging from the tight cluster of ams radiocarbon dates between 9000 and 8745 bp based on the known habitat preferences of the living species most of the tangzigou micromammals were arboreal or dwellers of the forest floor the micromammal assemblage thus indicates that subtropical forest including bamboo dominated the environment around tangzigou the assemblage is remarkable for the near absence of very small micromammal species such as small mice this bias appears to have been introduced by humans who collected the larger bodied species of micromammals for food this interpretation is supported by the presence of a large number of burned elements especially dentaries the analysis of the larger mammals also showed that tangzigou was a place where prehistoric people gathered to butcher the hunted scavenged animals

xas evidence for ni sequestration by siderite in a lateritic ni deposit from new caledonia mineralogical and spectroscopic analyses were conducted on a lateritic ni deposit from southern new caledonia results show that ni is incorporated in siderite feco3 found between 37 and 40 m depth in the laterite and saprolite units of the regolith sem edxs analyses of siderite rich samples indicate that a significant amount of nickel can be hosted by this crystalline phase 0 8 wt nio ni and fe k edge extended x ray absorption fine structure exafs spectroscopic analyses of the siderite rich samples from the regolith as well as comparison with synthetic ni bearing and ni free siderites demonstrate isomorphous substitution of ni2 for fe2 in the siderite structure linear combination fitting lcf of the ni k edge exafs data reveals that this ni bearing siderite species accounts for more than 90 of the total ni pool 1 wt nio in the siderite rich horizons of the regolith in addition lcf analysis of the exafs spectra indicates that goethite and serpentine are the major ni hosts in the upper horizons laterite and lower horizons saprolite of the regolith respectively formation of siderite an uncommon mineral species in such oxidized environments is attributed to the development of swampy conditions in organic rich lateritic materials that accumulated at the bottom of dolines these results thus show the importance of siderite as a host for nickel in lateritic ni deposits that have been affected by late hydromorphic and reducing conditions

reconstructing a mid cretaceous landscape from paleosols in western canada abstract the albian stage of the mid cretaceous was a time of equable climate conditions with high sea levels and broad shallow epeiric seas that may have had a moderating affect on continental climates a late albian landscape surface that developed during a regression and subsequent sea level rise in the western canada foreland basin is reconstructed on the basis of correlation of paleosols penetrated by cores through the paddy member of the peace river formation reconstruction of this landscape refines chronostratigraphic relationships and will benefit future paleoclimatological studies utilizing continental sphaerosiderite proxy records the paleosols developed in estuarine sandstones and mudstones and they exhibit evidence of a polygenetic history upon initial exposure and pedogenesis the paddy member developed deeply weathered well drained cumulative soil profiles later stages of pedogenesis were characterized by hydromorphic soil conditions the stages of soil development interpreted for the paddy member correlate with inferred stages of pedogenic development in time equivalent formations located both basinward and downslope upper viking formation and landward and upslope boulder creek formation on the basis of the genetic similarity among paleosols in these three correlative formations the paleosols are interpreted as having formed along a single continuous landscape surface results of this study indicate that the catena concept of pedogenesis along sloping landscapes is applicable to ancient successions sphaerosiderites in the paddy member paleosols are used to provide proxy values for meteoric 18o values at 52 n paleolatitude in the cretaceous western interior basin the meteoric 18o values are used to refine existing interpretations about the mid cretaceous paleolatitudinal gradient in meteoric 18o values and the mid cretaceous hydrologic cycle

evidence for multiple episodic mid holocene hypsithermal recorded in two soil profiles along an alluvial floodplain catena southeastern tennessee usa abstract floodplain soil paleosol successions are valuable archives for reconstructing pleistocene holocene climate changes but have been relatively unstudied in the southern appalachian region two soil profiles on a small floodplain in southeastern tennessee usa were described and sampled in detail using both pedological and geological approaches including stable carbon isotope analysis of soil organic matter som correlation between the 2 profiles was constrained by uncalibrated ams 14c ages of bulk humates and using som 13c values both mobile and immobile elements four distinct 2 5 4 shifts towards less negative 13c values for som suggest 300 yr cyclicity and transient warmer and drier climate events with either water stressed c3 vegetation or as much as 35 c4 plants present during the mid holocene these postulated multi episodic drier climate conditions have never before been documented in the southern appalachian region and are tentatively correlated with mid holocene warming and drying in the eastern us the nearly time equivalent mid holocene events documented in texas the us high plains and in the gulf of mexico high rates of floodplain sediment accumulation 0 5 3 mm yr high clay content and maintenance of poorly drained soil conditions favor preservation of high resolution climate archives in floodplain deposits by inhibiting oxidation and translocation of organic c

the good the bad and the ugly evaluating the radiocarbon chronology of the middle and late upper paleolithic in the enisei river valley south central siberia abstract the 14 c record for the upper paleolithic in siberia has remained largely unevaluated and includes good bad and ugly dates too often researchers accept either all published dates or only those dates that tend to support proposed chronological hypotheses regardless of sample quality and association this article systematically evaluates all published 14 c dates including several newly obtained ams dates from middle and late upper paleolithic sites in the enisei river valley of south central siberia to establish a reliable chronology for the region and address the tempo of modern human dispersals in siberia during late pleistocene times the revised chronology indicates humans were present before and after the last glacial maximum but absent during this climatic event results also suggest that human population in the region may have increased during the oldest dryas

recognizing the albian cenomanian oae1d sequence boundary using plant carbon isotopes dakota formation western interior basin usa analysis of bulk sedimentary organic matter and charcoal from an albian cenomanian fluvial estuarine succession dakota formation at rose creek pit rcp nebraska reveals a negative excursion of 3 in late albian strata overlying cenomanian strata have 13c values of 24 to 23 that are similar to pre excursion values the absence of an intervening positive excursion as exists in marine records of the albian cenomanian boundary likely results from a depositional hiatus the corresponding positive 13c event and proposed depositional hiatus are concordant with a regionally identified sequence boundary in the dakota formation d2 as well as a major regressive phase throughout the globe at the albian cenomanian boundary data from rcp confirm suggestions that some positive carbon isotope excursions in the geologic record are coincident with regressive sea level phases we estimate using isotopic correlation that the d2 sequence boundary at rcp was on the order of 0 5 m y in duration therefore interpretations of isotopic events and associated environmental phenomena such as oceanic anoxic events in the shallow marine and terrestrial record may be influenced by stratigraphic incompleteness further investigation of terrestrial 13c records may be useful in recognizing and constraining sea level changes in the geologic record

experimental study of thermal field evolution in the short impending stage before earthquakes phenomena at critical points are vital for identifying the short impending stage prior to earthquakes the peak stress is a critical point when stress is converted from predominantly accumulation to predominantly release we call the duration between the peak stress and instability the meta instability stage which refers to the short impending stage of earthquakes the meta instability stage consists of a steady releasing quasi static stage and an accelerated releasing quasi dynamic stage the turning point of the above two stages is the remaining critical point to identify the two critical points in the field it is necessary to study the characteristic phenomena of various physical fields in the meta instability stage in the laboratory and the strain and displacement variations were studied considering that stress and relative displacement can be detected by thermal variations and peculiarities in the full field observations we employed a cooled thermal infrared imaging system to record thermal variations in the meta instability stage of stick slip events generated along a simulated precut planer strike slip fault in a granodiorite block on a horizontally bilateral servo controlled press machine the experimental results demonstrate the following 1 a large area of decreasing temperatures in wall rocks and increasing temperatures in sporadic sections of the fault indicate entrance into the meta instability stage 2 the rapid expansion of regions of increasing temperatures on the fault and the enhancement of temperature increase amplitude correspond to the turning point from the quasi static stage to the quasi dynamic stage our results reveal thermal indicators for the critical points prior to earthquakes that provide clues for identifying the short impending stage of earthquakes

possible late holocene equatorial palaeoclimate record based upon soils spanning the medieval warm period and little ice age loboi plain kenya abstract wetland and floodplain soils in the east african rift of kenya provide a record of changing palaeoclimate and palaeohydrology compatible with climate records for the mid holocene through the late holocene medieval warm period ad 800 1270 and little ice age ad 1270 1850 documented previously in nearby lacustrine sites soils forming from volcaniclastic source materials in both loboi swamp and laterally adjacent kesubo marsh two wetland systems of latest holocene age were investigated using micromorphology whole soil geochemical analysis and stable isotope analysis of soil organic matter som wetland formation was abrupt and possibly related to climate shift from drier conditions associated with the mid holocene and medieval warm period to wetter conditions associated with the little ice age pre wetland sediments are floodplain volcanic sandy silts comprising buried inceptisols som 13c 15 pdb that fine upward to fine silt and clay which are overlain by clays and organic rich sediment peat som 13c 26 pdb stable isotopes record an abrupt shift from 20 to 40 c3 vegetation scrubland mixture of warm season grasses and acacia to 100 c3 wetland dominated by typha that occurred about 680 40 years bp c 14 date from seeds soils developed on the periphery of the wetland show evidence for fluctuations in hydrologic budget including siderite and redoximorphic features formed during wetter phases and vertic shrink swell and clay illuviation features developed during drier phases soils at kesubo marsh located 2 3 km east of loboi swamp consist of two buried mid holocene 4000 4600 years bp two c 14 dates from bulk som inceptisols developed from fluvially derived volcanic sand som 13c 15 pdb and separated from the latest holocene surface soil som 13c 17 5 pdb by an unconformity and prominent stone line both the loboi swamp and kesubo marsh surface soils show increases in zr fe and s relative to buried soils as well as higher leaching indices elevated zr may reflect zircon grain inputs by either aeolian dust during drier climate conditions or fluvial sheetflood inputs whereas higher leaching and elevated fe and s represent pyritization associated with wetter conditions

diagenetic siderite and other ferroan carbonates in a modern subsiding marsh sequence abstract mineralogical and carbon and oxygen stable isotope compositions in siderite rich concretions from a marsh within the mississippi river deltaic plain are highly variable the concretions have sideritic interiors and become more calcitic and dolomitic ankeritic near their margins 13c values of these concretions range from 10 0 to 7 4 pdb and 1 o values range from 2 4 to 8 9 pdb the stable isotope compositions exhibit two general trends one is a growth trend that shows 13c an 18o depletion from the centers to the margins of the nodules and bands the other is a progressive burial trend that shows 13c enrichments and 18o depletions at the centers of the concretions with depth a zonal model for carbonate precipitation with emphasis on an early fresh water non sulfidic methanic phase followed by a sulfidic stage associated with marine inundation of the marsh explains much of the observed carbon isotopic variations mixing of fluids plus precipitation in a partially closed chemical microsystem accounts for most of the oxygen isotope fractionations documented between growth layers and casts doubt on the utility of change in 18o shifts as an indicator of depth or relative temperature of concretion formation for concretions that form in coastal environments

groundwater table fluctuations recorded in zonation of microbial siderites from end triassic strata in a terrestrial triassic jurassic boundary succession of southern sweden perfectly zoned sphaerosiderites are restricted to a specific sandy interval deposited during the end triassic event underlying and overlying this sand interval there are several other types of siderite micromorphologies i e poorly zoned sphaerosiderite spheroidal ellipsoid siderite spherical siderite and rhombohedral siderite siderite overgrowths occur mainly as rhombohedral crystals on perfectly zoned sphaerosiderite and as radiating fibrous crystals on spheroidal siderite concretionary sparry microspar and or micritic siderite cement postdate all of these micromorphologies the carbon isotope composition of the siderite measured by conventional mass spectrometry shows the characteristic broad span of data probably as a result of multiple stages of microbial activity sims secondary ion mass spectrometry revealed generally higher 13c values for the concretionary cement than the perfectly zoned sphaerosiderite spheroidal siderite and their overgrowths which marks a change in the carbon source during burial all the various siderite morphologies have almost identical oxygen isotope values reflecting the palaeo groundwater composition a pedogenic freshwater origin is supported by the trace element compositions of varying fe mn ratios and low mg contents fluctuating groundwater is the most likely explanation for uniform repeated siderite zones of varying fe mn ratios reflecting alternating physiochemical conditions and hostility to microbial life activity bacterially mediated siderite precipitation likely incorporated mn and other metal ions during conditions that are not favourable for the bacteria and continued with fe rich siderite precipitation as the physico chemical conditions changed into optimal conditions again reflecting the response to groundwater fluctuations

anomalous diffuse co2 emission prior to the january 2002 short term unrest at san miguel volcano el salvador central america on january 16 2002 short term unrest occurred at san miguel volcano a gas and steamash plume rose a few hundred meters above the summit crater an anomalous microseismicity pattern about 75 events between 7 30 and 10 30 hours was also observed continuous monitoring of co2 efflux on the volcano started on november 24 2001 in the attempt to provide a multidisciplinary approach for its volcanic surveillance the background mean of the diffuse co2 emission is about 16 g m 2 d 1 but a 17 fold increase up to 270 g m 2 d 1 was detected on january 7 nine days before the january 2002 short term unrest at san miguel volcano these observed anomalous changes on diffuse co2 degassing could be related to either a sharp increase of co2 pressure within the volcanic hydrothermal system or degassing from an uprising fresh gas rich magma within the shallow plumbing system of the volcano since meteorological fluctuations cannot explain this observed increase of diffuse co2 emission

paleopedologic and paleohydrologic records of precipitation seasonality from early pennsylvanian underclay paleosols u s a underclays in the crooked fork group lower pennsylvanian atokan langsettian in eastern tennessee u s a are paleosols associated with fourth order depositional sequences that record changing paleohydrologic conditions during their formation climate changes possibly milankovitch driven resulted in evolution of soil landscapes from well drained seasonally wet floodplains and delta plains dominated by vertic vertisol like paleosols to very poorly drained everwet swamps dominated by sideritic gley paleosols coals paleohistosols cap most underclays and record peat swamp development during everwet conditions followed by marine submergence pedogenic slickensides and angular blocky ped structures in conjunction with illuviated clay pore fillings and sepic plasmic microfabric indicate an initial better drained phase of paleosol development stage i gley overprinting characterized by drab low chroma paleosol colors fe reduction in upper portions of paleosols sideritic rhizocretions sphaerosiderite and pyrite nodules extensive leaching and translocation of alkali and alkaline earth elements and kaolinitization of smectites and hydroxy interlayer vermiculite hiv indicate a later poorly drained stage of paleosol development characterized by saturated conditions moderate to low eh and low ph stage ii as well as peat swamp development lastly burial and juxtaposition of marine facies on top of terrestrial deposits terminated paleosol and peat development stage iii paleosols likely formed under conditions of marked seasonality of rainfall judging from both modern analog systems in sumatra and pennsylvanian paleoclimate models the chemical index of alteration without potash cia k was used as a proxy for atokan paleoprecipitation estimated as 1300 mm yr this estimate is comparable with mean annual precipitation map in modern tropical to subtropical rainy environments

ams 14c chronology of the world s southernmost woolly mammoth mammuthus primigenius blum the world s definite southernmost woolly mammoth record is a molar from ji nan around 36 degrees n shandong province china ams c 14 dating of the specimen gave a conventional c 14 age of 33 150 250 bp the period of 40 30 ka bp corresponds to the later phase of the marine oxygen isotope stage 3 mis 3a recognized as the global interstadial of the last glacial period however it is known that the winter monsoon strengthened in asia during the period 35 33 ka bp and the age of the woolly mammoth specimen from ji nan corresponds to that age the specimen suggests that this area became cold and dry in 33 ka bp and grassland or open forest suitable habitat for woolly mammoths developed during this short time span this age is similar to the age of the southernmost woolly mammoth record in europe therefore supporting a hypothesis by porter and an 1995 correlation between climate events in the north atlantic and china during the last glaciation nature 375 305 308 that an important component of chinese palaeoclimates may be linked to changes in north atlantic oceanic conditions c 2007 elsevier ltd all rights reserved

background stress state before the 2008 wenchuan earthquake and the dynamics of the longmen shan thrust belt a stress reconstruction was performed based on focal mechanisms around the longmen shan region prior to the 2008 ms 8 0 wenchuan earthquake using a newly developed algorithm known as mca the method determines the stress tensor including principal axes orientations and quantitative stress values such as the effective confining pressure and maximum shear stress the results of the mca application using data recorded by the regional network from 1989 to april 2008 show the background stress state around the longmen shan belt before the wenchuan earthquake the characteristics of the stress orientation reveal that the longmen shan region is primarily under the eastward extrusion of the eastern tibetan plateau non uniform quantitative stress distributions show low stress levels in the upper crust of the middle longmen shan segment which is consistent with the observed high angle reverse faulting associated with the 2008 wenchuan earthquake in contrast other study areas such as the bayankela block and the nw strip extending to the sichuan basin show high stress intensity this feature coincides with heterogeneity in the wave speed image of the upper crust in this region which shows high s wave speed in the high stress areas and comparatively low s wave speed in low stress areas deformation features across the longmen shan belt with the slow rates of convergence determined by gps and the distribution of surface deformation rates also are in keeping with our stress results we propose a dynamic model in which sloping uplift under the longmen shan which partly counteracts the pushing force from the eastern plateau causes the low quantitative stresses in the upper crust beneath the longmen shan the decreasing gravitational potential energy beneath the longmen shan leads to earthquake thrust faulting and plays an important role in the geodynamics of the area that results from ductile thickening of the deep crust behind the sichuan basin creating a narrow steep margin

effect of bacteria on the elemental composition of early diagenetic siderite implications for palaeoenvironmental interpretations many ancient early diagenetic siderite concretions are thought to have been precipitated by microbially mediated reactions and their trace element chemistry has been used to infer palaeoenvironments of formation e g marine versus freshwater in this study pure cultures of the microorganism geobacter metallireducens were used to precipitate siderite in the laboratory at a range of temperatures 18 40 c magnesium and calcium in three different ratios 3 1 as in seawater 1 1 and 1 3 as in freshwater or manganese were added to some cultures at each incubation temperature to study trace element incorporation the siderite produced exhibited the rhombohedral crystal form typical of concretionary siderite however this microbial siderite did not simply retain the trace element chemistry of the water from which it precipitated as is assumed in palaeoenvironmental interpretations instead manganese and calcium incorporation were found to be inversely proportional to the rate of microbial activity which itself is dependent upon the nutritional status of the microorganisms magnesium incorporation was found to be rate independent and at high mg ca ratios it caused inhibition of calcium incorporation in short the influence of microorganisms on the trace element composition of early diagenetic siderite must be taken into account in order to produce valid palaeoenvironmental interpretations

asynchronous holocene optimum of the east asian monsoon abstract the spatial and temporal distribution of summer monsoon precipitation or effective moisture during the holocene has been reconstructed on the basis of geological data including lake levels pollen profiles and loess paleosol records in addition the summer july precipitation increment effective precipitation and monsoon strength index have been obtained from numerical modeling experiments both geological data and numerical modeling indicate that the holocene optimum as defined by peak east asian summer monsoon precipitation was asynchronous in central and eastern china reaching a maximum at different times in different regions e g ca 10 000 8000 yr ago in northeastern china 10 000 7000 yr ago in north central and northern east central china ca 7000 5000 yr ago in the middle and lower reaches of the yangtze river and ca 3000 yr ago in southern china in southwestern china the maximum appeared ca 11 000 yr ago but probably was related to the maximum landward extension of the indian summer monsoon the regional shift in the maximum precipitation belt from northwest to southeast over the past 10 000 yr is interpreted as a response to changing seasonality related to orbital forcing of the climate the southeastward shift of the east asian summer monsoon maximum is consistent with the progressive weakening of the summer monsoon as the summer solar radiation anomaly decreased progressively through the holocene and the east asian monsoon index declined while the early maximum in southwestern china matches the maximum of the indian monsoon index

quaternary environmental changes in the drylands of china a critical review abstract this paper reviews our current understanding of quaternary climate and landscape changes in the desert areas of northern china a key portion of the middle latitude drylands on earth combining earlier studies with our recent research and experience we offer a comprehensive picture of the state of chinese deserts during the quaternary and in the interest of enhancing future research identify knowledge gaps and areas of uncertainty lacustrine deposits found over an area ranging from china s western taklamakan desert to the eastern hunshandake sandy lands suggest that extensive lakes occurred in china s deserts during the pleistocene analysis of digital elevation models from srtm shuttle radar topography mission data supports this interpretation and shows the significant extent of these former lakes new estimates of mean annual evaporation of ca 1000 mm from lake surfaces and ca 100 mm from land surfaces confirms that local and regional rainfall is critical for maintenance of desert lakes in this temperate zone especially during intervals when the mean annual rainfall is more than 100 mm rapid shifts between sand seas and lakes in geologically and environmentally diverse settings suggest that the drylands of china are very sensitive ephemeral systems and not long lasting as previously thought available chronologies suggest that there were large lakes in the western taklamakan desert and the chadamu basin during mis marine isotope stage 3 at 30 ka probably related to a period of strong influence of northern hemispheric westerly winds channels and elevation models revealed by srtm data and remains of lacustrine sediments also indicate that there was a large lake in the hunshandake sandy lands in the eastern portion of the desert belt during the quaternary there is significant evidence that during the middle holocene strong summer monsoons led to a relatively large increase in moisture availability in the entire desert belt of northern china lacustrine records from the badain jaran desert in western inner mongolia suggest that it was generally dry before 10 cal ka becoming wetter from 10 to 4 cal ka and dry again afterwards study of palaeosols widely occurring in dune stratigraphy in the eastern portion of the desert belt suggests that there was a period of wet and warm climate in this region during the mid holocene optimum at a minimum between 6 ka and 4 ka but possibly lasting longer recent observations dealing with the generation and transport of dust from central asia indicate that the causal relationship between sand seas and loess sequences is not as close as previously assumed these results suggest that there is an urgent need to examine whether the frequency and amplitude of climatic variation in chinese deserts are somehow similar to that having occurred in the sahara desert of north africa deserts in northern china were also important focal regions for neolithic cultures during intervals when environmental conditions supported a denser vegetative cover there is evidence that some areas of woody vegetation to the west of badain jaran desert were deforested by humans by ca 4000 yr b p although it is still debatable whether humans have had a significant impact in other areas at that time opinions on the severity of desertification vary and are sometimes contradictory due to the lack of long term field based investigations

u series dating and taphonomy of quaternary vertebrates from brazilian caves abstract the geochronology and taphonomy of internationally important fossil bearing cave deposits were studied both in the semi arid northern bahia area and the subtropical southeastern lagoa santa area of brazil taphonomic analysis suggests that the processes responsible for bone accumulation in the brazilian caves vary between sites and taphonomic bias can therefore be significant in causing differences in faunal composition in the toca da boa vista caves the presence of single articulated skeletons and the entrance related distribution indicate that random penetration of animals is the main mechanism of fossil accumulation a process that biases the assemblage to smaller species and takes place over extended time periods in nearby toca dos ossos cave transport by runoff in the cave river is predominant and biases the fauna remains to larger more robust bones and species deposition probably also occurred only at times of enhanced runoff giving a more contemporaneous assemblage similar processes were responsible for emplacement of the copious fossil remains in the more humid lagoa santa area where terrigenous fossil deposits are found intercalated by massive speleothem calcite layers in this area runoff under a drier climate probably accounts for the sediment emplacement inside caves in both areas the mode of emplacement implies bias in the fossil record resulting in fossil assemblages that do not mirror surface faunas limiting palaeoenvironmental reconstruction mass spectrometric u series analysis of speleothem calcite overlaying fossil remains gives minimum ages for fossil deposition these ages confirm the previous view that many of the deposits derive from the late glacial but also show that much older material some 350 000 yr is also present the habitat requirements of critical fossil species such as bats and monkeys strongly suggest that they derive from much wetter periods when forest cover was present in the currently semi arid northern bahia area taphonomy exerts a major control on the diversity and mode of emplacement of cave fossil deposits in eastern brazil and thus detailed sedimentological and hydrological studies coupled with a sound geochronological approach are essential in quantifying the relative importance of each taphonomic processes before faunal and palaeoecological interpretations can be attempted

extinction chronology of the woolly rhinoceros coelodonta antiquitatis in the context of late quaternary megafaunal extinctions in northern eurasia abstract megafaunal extinctions in northern eurasia excluding mediterranean islands since the last interglacial claimed about 37 of species with body weights 44 kg here we review the dating evidence for the timings of these extinctions which were staggered over tens of millennia moreover individual species disappeared at different times in different geographical areas for example cave bear probably disappeared ca 30 5 28 5 ka at approximately the onset of gs 3 beginning of lgm whereas cave lion survived until the lateglacial ca 14 ka others survived into the holocene woolly mammoth until ca 10 7 ka in the new siberian islands and ca 4 ka on wrangel island giant deer to at least 7 7 ka in western siberia and european russia it is evident that climatic and vegetational changes had major impacts on species ranges and moreover the contrasting chronologies and geographical range contractions are consistent with environmental drivers relating to their differing ecologies however the possible role of humans in this process has still to be satisfactorily explored we present a detailed review of the radiocarbon record and extinction chronology of an exclusively northern eurasian species the woolly rhinoceros coelodonta antiquitatis an animal adapted to feeding on low growing herbaceous vegetation and a dry climate with minimal snowfall during the last glacial the overall time averaged range of c antiquitatis extended across most of northern eurasia but the species failed to reach north america on the basis of 233 ultrafiltered ams radiocarbon dates together with 50 others which pass our auditing criteria we reconstruct a detailed chronology for this species c antiquitatis was widespread over most of the time span covered by radiocarbon dating but from ca 35 ka calibrated it apparently contracted towards the east culminating in its probable extinction ca 14 ka with the latest dates from north eastern siberia it disappeared from britain at the western more oceanic end of its range at ca 35 ka bp apparently corresponding with the onset of interstadial gi 7 in north eastern siberia c antiquitatis survived through much of gi 1d e and probably went extinct at or close to the onset of gi 1c allerod ca 13 9 ka bp its final extinction probably relates to lateglacial interstadial warming and increased precipitation especially snowfall accompanied by the replacement of low growing herbaceous vegetation by shrubs and trees the survival of woolly rhinoceros in north eastern siberia when it had disappeared further west may relate to the later persistence of open vegetation in that region the timing of its final extinction could relate to the fact that the lateglacial interstadial was significantly warmer than any other event in the previous 50 millennia there are indications of gaps in the pattern of dates in certain areas that may have significance in terms of temporary absences of c antiquitatis some of which may correspond to interstadial phases the radiocarbon record of c antiquitatis is still poor in some potentially important areas and further work will corroborate or reject the hypotheses of regional gaps in occurrence and might perhaps reveal currently unsuspected later survival

stratigraphic implications of meteoric sphaerosiderite 18o values in paleosols of the cretaceous albian boulder creek formation ne british columbia foothills canada abstract the md 80 08 coal exploration core from the albian boulder creek formation of northeastern british columbia contains 90 m of alluvial strata that underwent extensive pedogenic modification gleyed colors pedogenic slickensides clay coatings mottling sphaerosiderite and sedimentary pyrite characterize the paleosols the isotopic compositions of 30 sphaerosiderite bearing horizons commonly show trends of invariant 18o and variable 13c values equal area plots of 18o vs 13c were used to construct meteoric sphaerosiderite lines msls the msls indicate that meteoric groundwater compositions ranged from approximately 11o oo to 16o oo smow the sphaerosiderite 18o values indicate formation in shallow groundwaters predominantly recharged by local precipitation the sphaerosiderite isotopic compositions are a proxy record of mid cretaceous precipitation and are useful for quantifying changes in the hydrologic cycle during humid greenhouse periods micromorphology of a 1 15 meter interval 69 75 68 6 m with a 1 31o oo increase in the average 18o values records a polygenetic history of paleosol development the pedocomplex has a four stage developmental history characterized by 1 an initial well drained phase with wet dry cycles and relatively low baselevel 2 erosion baselevel rise and coarser grained sedimentation 3 saturated reducing soil conditions high baselevel with some marine influence on pedogenesis and 4 meteoric water dominated hydromorphic soil conditions high baselevel and sphaerosiderite precipitation the 18o excursion recorded through this interval reflects minor mixing of marine and meteoric groundwaters the modal abundance of pyrite and increased mg ca mg and mg fe cation ratios in the sphaerosiderites further substantiate marine influence on pedogenesis the alluvial section of the boulder creek formation is aggradational and several changes in baselevel recorded in the paleosols are interpreted to have been driven by minor parasequence scale changes in relative sea level

testing the savannah corridor hypothesis during mis2 the boh dambang hyena site in southern cambodia abstract the boh dambang karstic site in southern cambodia kampot province is a mammal bone rich deposit in a hyena site very few hyena sites have been recovered in the pleistocene of southeast asia thus little information is known about the foraging abilities of hyenas during that period and their decline in the region while the other hypercarnivores tiger leopard and dhole persisted until present day to constrain the site we applied luminescence red tl and single grain osl esr and u th dating methods to the sediments and faunal teeth respectively the resulting age estimates suggest that the site represents an accumulation of a young deposit with faunal teeth in the range of 25 18 ka that was last exposed to sunlight between 8 and 7 ka and an older deposit containing older teeth 100 80 ka that have been eroded from the upper caves in the system and incorporated into the younger deposit thus the faunal age of 25 18 ka mis2 provides the best estimate for the age of the hyena site during lgm 26 5 19 ka we analysed the assemblage of isolated teeth in terms of taxonomic diversity and abundance the role of bone accumulators either carnivores or rodents has been precised through a taphonomic analysis diet was reconstructed through measurement of 13 c values of tooth enamel the taphonomic analysis reveals that the hyenas were the main bone accumulators at boh dambang porcupines were aslo a factor in the accumulation of remains the results show that the spotted hyenas hunted large sized herbivores 600 kg in a mixed environment dominated by grassland these data along with evidence from other pleistocene faunas from southeast asian mainland in terms of prey preference of hyenas rhinoceroses versus large bovines also reveal marked differences in relation to habitat type possible causes of the decline of the spotted hyena in the indochinese sub region hypercarnivory high trophic level comparable foraging strategies with hunters gatherers and climatic changes are tentatively proposed at this point

a sustainable review of the middle pleistocene benchmark sites including the ailuropoda stegodon faunal complex the proboscidean point of view abstract the different ecologies times of extinction and last stand of both elephas and stegodon in south east asia cover almost two million years in the middle pleistocene both taxa belong to the complex ailuropoda stegodon this regional complex is considered to have a chronological significance and further palaeoecological palaeobiogeographical or biochronological studies use this assemblage as a benchmark nevertheless such studies do not provide sufficient information regarding site formation and duration to be consistent enough to do so at an appropriate resolution mis timescale focussing attention on the occurrence of proboscideans a critical review of the robustness of the geological taphonomical and chronological data of middle pleistocene faunal assemblages suggests the necessity to undertake a deep reappraisal of this biochronological benchmark recommendations were provided in the 1980s not to use mixtures of faunal assemblages and progress in geochronology for two decades is available nevertheless a review of proboscideans suggests the necessity of a severe revision leading to scepticism concerning the use of the ailuropoda stegodon complex as an ecological marker extended to other taxa this review casts serious doubts on former and current paleoecological modellings and studies

tectonically induced anomalies without large earthquake occurrences in this study we documented a case involving large scale macroscopic anomalies in the xichang area southwestern sichuan province china from may to june of 2002 after which no major earthquake occurred during our field survey in 2002 we found that the timing of the high frequency occurrence of groundwater anomalies was in good agreement with those of animal anomalies spatially the groundwater and animal anomalies were distributed along the anninghe zemuhe fault zone furthermore the groundwater level was elevated in the northwest part of the zemuhe fault and depressed in the southeast part of the zemuhe fault zone with a border somewhere between puge and ningnan counties combined with microscopic groundwater geodetic and seismic activity data we infer that the anomalies in the xichang area were the result of increasing tectonic activity in the sichuan yunnan block in addition groundwater data may be used as a good indicator of tectonic activity this case tells us that there is no direct relationship between an earthquake and these anomalies in most cases the vast majority of the anomalies including microscopic and macroscopic anomalies are caused by tectonic activity that is these anomalies could occur under the effects of tectonic activity but they do not necessarily relate to the occurrence of earthquakes

micromorphology and stable isotope geochemistry of historical pedogenic siderite formed in pah contaminated alluvial clay soils tennessee u s a abstract alluvial clay soil samples from six boreholes advanced to depths of 400 450 cm top of limestone bedrock from the chattanooga coke plant ccp site were examined micromorphologically and geochemically in order to determine if pedogenic siderite feco3 was present and whether siderite occurrence was related to organic contaminant distribution samples from shallow depths were generally more heavily contaminated with polycyclic aromatic hydrocarbons pahs than those at greater depth the upper 1 m in most boreholes consisted of mixtures of anthropogenically remolded clay soil fill containing coal clinker cinder grains and limestone gravel most layers of coarse fill were impregnated with creosote and coal tar most undisturbed soil below 1 m depth consisted of highly structured clays exhibiting fine subangular blocky ped structures as well as redox related features pedogenic siderite was abundant in the upper 2 m of most cores and in demonstrably historical 100 years old soil matrices two morphologies were identified 1 sphaerosiderite crystal spherulites ranging from 10 to 200 m in diameter and 2 coccoid siderite comprising grape like clusters of crystals 5 20 m in diameter the siderite formed in both macropores and within fine grained clay matrices indicates development of localized anaerobic low eh conditions possibly due to microbial degradation of organic contaminants stable isotope compositions of the siderite have 13c values spanning over 25 7 to 18 vpdb indicating fractionation of dic by multiple microbial metabolic pathways but with relatively constant 18o values 4 8 0 66 vpdb defining a meteoric sphaerosiderite line msl calculated isotope equilibrium water 18o values from pedogenic siderites at the ccp site are from 1 to 5 per mil lighter than the groundwater 18o values that we estimate for the site if confirmed by field studies in progress this observation might call for a reevaluation of low temperature siderite water 18o fractionations investigations at the ccp site thus provide valuable information on the geochemical conditions under which siderite can form in modern soils and thus insight on controls on siderite formation in ancient soils

spherulitic siderites in the holocene coastal deposits of korea eastern yellow sea elemental and isotopic composition and depositional environment abstract siderite concretions are recovered from both freshwater unit ii and tidal unit i deposits in the holocene macrotidal flat of kyunggi bay west coast of korea siderites from both units show a spherulitic and well rounded texture and well developed equant rhombs on the external surfaces the size of the concretions in unit ii 50 150 m in diameter is normally larger than that in unit i 10 20 m the siderites in unit ii are chemically pure and highly enriched in fe whereas those of unit i are relatively impure and distinctly zoned demarcating high mn up to 69 1 mol in the core and high fe up to 75 9 mol in the margin within siderites of unit i substitution for fe by ca and mg reaches up to 20 3 mol mean 15 1 mol and 16 1 mol mean 12 6 mol respectively bulk 18 o values 0 7 to 1 3 peedee belemnite pdb for siderites in unit i are relatively higher than those 7 1 to 0 5 pdb in unit ii regardless of units siderite 13 c values 21 3 to 11 2 pdb are persistently low indicating microbially mediated precipitation at shallow burial depth extensive mn ca and mg substitution coupled with enrichment of 18 o in the siderites of unit i seems to reflect marine influence during the holocene transgression the occurrence of early diagenetic siderites provides supporting evidence on the depositional environment marine vs non marine of the holocene muddy coastal deposits of korea eastern yellow sea

characteristics of pleistocene megafauna extinctions in southeast asia the extinction of large bodied taxa from the pleistocene in southeast asia is examined although the chronological resolution of these extinctions is poor and number of excavations in the region relatively few broad characteristics of these extinctions can be described many taxa which became extinct appear to have been endemic to regions within southeast asia while some taxa which experienced extinction or severe range reduction occurred in several regions members of the latter group include proboscideans stegodon and palaeloxodon the pygmy hippopotamus hexaprotodon the orangutan pongo hyenas crocuta and hyaena the giant panda ailuropoda tapirs tapirus and megatapirus rhinoceroses rhinoceros and the giant asian ape gigantopithecus the loss of these species cannot be assigned to a single cause rather their disappearance is likely tied to both climatic and human agents unlike other regions which experienced megafauna extinctions eustatic changes in sea level in southeast asia seems to have been an important factor

hydrological and climatic changes in deserts of china since the late pleistocene article i nfo article history large areas in western china were wetlands or less arid between 40 and 30 ka corresponding to the greatest lake period on the adjacent tibetan plateau during the last glacial maximum some of these western chinese deserts again experienced wetter conditions however at the same time the sandy lands in the eastern chinese desert belt experienced an activation of aeolian dunes while interpretations of the mid holocene environment in the deserts of china are controversial it is quite likely that it was more humid not only in the eastern areas influenced by monsoon climate systems but also in the western deserts where moisture is currently associated with westerlies evaluation of lacustrine records in the lakes recharged by dryland rivers and the complex interactions of these systems as well as other paleoenvironmental proxies such as the artemisia chenopodiaceae ratio should be interpreted with greater caution facing the highlighted uncertainties in our understanding of climate changes in chinese deserts it is hoped that this special issue will improve our knowledge considerably

the youngest stegodon remains in southeast asia from the late pleistocene archaeological site liang bua flores indonesia stegodon remains originating from late pleistocene layers of the archaeological cave site liang bua on the indonesian island of flores are described as a new endemic dwarf subspecies stegodon florensis insularis subsp nov some fossil stegodon fragments were found in association with the recently described remains of homo floresiensis but many occur in levels with high artefact concentrations the direct ancestor is the larger sized s florensis florensis known from early pleistocene and early middle pleistocene sites on flores the assemblage from liang bua comprises mostly dental and skeletal elements of juvenile individuals s f insularis is characterized by an advanced molar ridge formula and diminutive size on average the molars are 30 per cent smaller in linear dimensions as compared to the ancestral species hominin activities are likely to have played a role in the stegodon bone accumulation at liang bua

sem and light microscopic observations of minerals in bog ores of the belgian campine abstract stoops g 1983 sem and light microscopic observations of minerals in bog ores of the belgian campine geoderma 30 179 186 soft bog ore deposits are frequently present in alluvial soils of the nete valley province of antwerp belgium a profile was studied consisting of four layers of which the upper three were analyzed with the light microscope and sem scanning electron microscope the top layer consisted mainly of clay and fragmented diatom shells isotropic fe oxihydrates and radiating goethite needles were present in the underlying limonitic layer siderite and vivianite were found in the third layer the former often present in the wall of root channels whereas the latter was frequently found within the channels vivianite was also found associated with decaying roots or alone inside root channels pyrite framboids were also found in the lower part of the profile the presence close to each other of different minerals such as goethite pyrite siderite and vivianite cannot be explained by macroenvironmental mineral equilibria alone it requires the existence of different microenvironments which can vary in time and place the study of such microenvironments however requires additional in situ microchemical submicroscopic techniques

isotopic composition of low latitude paleoprecipitation during the early cretaceous the response of the hydrologic cycle in global greenhouse conditions is important to our understanding of future climate change and to the calibration of global climate models past greenhouse conditions such as those of the cretaceous can be used to provide empirical data with which to evaluate climate models recent empirical studies have utilized pedogenic carbonates to estimate the isotopic composition of meteoric waters and calculate precipitation rates for the aptianalbian these studies were limited to data from mid 35 n to high 75 n paleolatitudes and thus future improvements in accuracy will require more estimates of meteoric water compositions from numerous localities around the globe this study provides data for tropical latitudes 18 5 n paleolatitude from the tlayua formation puebla mexico in addition the study confi rms a shallow nearshore depositional environment for the tlayua formation petrographic observations of fenestral fabrics gypsum crystal molds stromatolitic structures and pedogenic matrix birefringence fabric support the interpretation that the strata represent deposition in a tidal fl at environment carbonate isotopic data from limestones of the tlayua formation provide evidence of early meteoric diagenesis in the form of meteoric calcite lines these trends in 18 o versus 13 c

pedogenesis of late quaternary deposits northern kyonggi bay korea implications for relative sea level change and regional stratigraphic correlation abstract late pleistocene and early holocene paleosols are described from construction pits and boreholes in the northern kyonggi bay west coast of korea thin section petrography chemistry clay mineralogy and geotechnical properties of the paleosols were examined to infer relative sea level fluctuations during the late quaternary relict laminae and gradational contacts with underlying tidal rhythmites confirm that the late pleistocene paleosol is a pedogenically altered tidal deposit illuvial clay coatings rootlets and enrichment of kaolinite and chemically stable oxides indicate that pedogenesis occurred on a well drained stable surface during the last glacial period redoximorphic features such as drab colored root traces and sphaerosiderite however suggest that waterlogged conditions developed temporarily due to a rise of the water table at the end of the last glacial period as sea level rose an early holocene paleosol formed in freshwater bog deposits burying the late pleistocene paleosol the early holocene paleosol has abundant sphaerosiderites and organic material the presence of weakly developed illuvial clay coatings oxidized siderites and pellets however indicates oxidizing condition associated with water table fall occurred during the early holocene despite the similarity in the degree of chemical and clay mineralogical weathering the late pleistocene paleosol is distinguished from its early holocene counterpart by thicker and more abundant illuvial clay coatings more fe 2 o 3 and a greater degree of consolidation duration of pedogenesis might be a primary cause for the difference of the pedofeatures with climate playing a secondary role the widespread presence of similar late pleistocene paleosols highlights its significance as a key stratigraphic marker for regional correlations along the west coast of korea

anomalous streamflow and groundwater level changes before the 1999 m7 6 chi chi earthquake in taiwan possible mechanisms streamflow recorded by a stream gauge located 4 km from the epicenter of the 1999 m7 6 chi chi earthquake in central taiwan showed a large and rapid anomalous increase of 124 m3 s starting 4 days before the earthquake this increase was followed by a comparable co seismic drop to below the background level for 8 months in addition groundwater levels recorded at a well 1 5 km east of the seismogenic fault showed an anomalous rise 2 days before the earthquake and then a unique 4 cm drop beginning 3 h before the earthquake the anomalous streamflow increase is attributed to gravity driven groundwater discharge into the creek through the openings of existing fractures in the steep creek banks crossed by the upstream shueilikun fault zone as a result of pre earthquake crustal buckling the continued tectonic movement and buckling together with the downward flow of water in the crust may have triggered the occurrence of some shallow slow slip events in the shueilikun and other nearby fault zones when these events propagate down dip to decollement where the faults merges with the seismogenic chelungpu fault they may have triggered other slow slip events propagating toward the asperity at the hypocenter and the chelungpu fault these events may then have caused the observed groundwater level anomaly and helped to trigger the earthquake

recognition of interfluve sequence boundaries integrating paleopedology and sequence stratigraphy in shallow marine and coastal plain strata sequence boundaries are easily recognized at the base of incised valley fills between valleys however it is more difficult to recognize sequence boundaries where they are expressed as interfluve paleosols we suggest that interfluve paleosols can be most reliably identified using a combination of 1 stratigraphic position 2 field observations such as thickness structure color and degree of rooting and 3 micromorphological features such as bioturbation fabric clay coatings ferruginous features and siderite and barite only micromorphology permits recognition of temporal changes in drainage surface stability and protracted pauses in sedimentation that typify these surfaces this three part approach has been successfully employed to identify interfluve sequence bounding paleosols in the cenomanian dunvegan formation in alberta and british columbia canada