origin and composition of three heterolithic boulder and cobble bearing deposits overlying the murray and stimson formations gale crater mars heterolithic boulder containing pebble strewn surfaces occur along the lower slopes of aeolis mons mt sharp in gale crater mars they were observed in hirise images acquired from orbit prior to the landing of the curiosity rover the rover was used to investigate three of these units named blackfoot brandberg and bimbe between sols 1099 and 1410 these unconsolidated units overlie the lower murray formation that forms the base of mt sharp and consist of pebbles cobbles and boulders blackfoot also overlies portions of the stimson formation which consists of eolian sandstone that is understood to significantly postdate the dominantly lacustrine deposition of the murray formation blackfoot is elliptical in shape 62 26 m while brandberg is nearly circular 50 55 m and bimbe is irregular in shape covering about ten times the area of the other two the largest boulders are 1 5 2 5 m in size and are interpreted to be sandstones as seen from orbit some boulders are light toned and others are dark toned rover based observations show that both have the same gray appearance from the ground and their apparently different albedos in orbital observations result from relatively flat sky facing surfaces chemical observations show that two clasts of fine sandstone at bimbe have similar compositions and morphologies to nine chemcam targets observed early in the mission near yellowknife bay including the bathurst inlet outcrop and to at least one target pyramid hills sol 692 and possibly a cap rock unit just north of hidden valley locations that are several kilometers apart in distance and tens of meters in elevation these findings may suggest the earlier existence of draping strata like the stimson formation that would have overlain the current surface from bimbe to yellowknife bay compositionally these extinct strata could be related to the siccar point group to which the stimson formation belongs dark massive sandstone blocks at bimbe are chemically distinct from blocks of similar morphology at bradbury rise except for a single float block oscar sol 516 conglomerates observed along a low sinuous ridge at bimbe consist of matrix and clasts with compositions similar to the stimson formation suggesting that stream beds likely existed nearly contemporaneously with the dunes that eventually formed the stimson formation or that they had the same source material in either case they represent a later pulse of fluvial activity relative to the lakes associated with the murray formation these three units may be local remnants of infilled impact craters especially circular shaped brandberg decayed buttes patches of unconsolidated fluvial deposits or residual mass movement debris their incorporation of stimson and murray rocks the lack of lithification and appearance of being erosional remnants suggest that they record erosion and deposition events that post date the exposure of the stimson formation

concentration of h si cl k fe and th in the low and mid latitude regions of mars 1 we report maps of the concentrations of h si cl k fe and th as determined by the gamma ray spectrometer grs on board the 2001 mars odyssey mission for 45 latitudes the procedures by which the spectra are processed to yield quantitative concentrations are described in detail the concentrations of elements determined over the locations of the various mars landers generally agree well with the lander values except for fe although the mean of the grs fe data agrees well with that of martian meteorites the water equivalent concentration of hydrogen by mass varies from about 1 5 to 7 5 by mass with the most enriched areas being near apollinaris patera and arabia terra cl shows a distribution similar to h over the surface except that the cl content over medusae fossae is much greater than elsewhere the map of fe shows enrichment in the northern lowlands versus the southern highlands silicon shows only very modest variation over the surface with mass fractions ranging from 19 to 22 over most of the planet though a significant depletion in si is noted in a region west of tharsis montes and olympus mons where the si content is as low as 18 k and th show a very similar pattern with depletions associated with young volcanic deposits and enrichments associated with the tes surface type 2 material it is noted that there appears to be no evidence of significant globally distributed thick dust deposits of uniform composition

chemistry mineralogy and grain properties at namib and high dunes bagnold dune field gale crater mars a synthesis of curiosity rover observations the mars science laboratory curiosity rover performed coordinated measurements to examine the textures and compositions of aeolian sands in the active bagnold dune field the bagnold sands are rounded to subrounded very fine to medium sized 45 500 m with 6 distinct grain colors in contrast to sands examined by curiosity in a dust covered inactive bedform called rocknest and soils at other landing sites bagnold sands are darker less red better sorted have fewer silt sized or smaller grains and show no evidence for cohesion nevertheless bagnold mineralogy and rocknest mineralogy are similar with plagioclase olivine and pyroxenes in similar proportions comprising 90 of crystalline phases along with a substantial amorphous component 35 15 yet bagnold and rocknest bulk chemistry differ bagnold sands are si enriched relative to other soils at gale crater and h 2o s and cl are lower relative to all previously measured martian soils and most gale crater rocks mg ni fe and mn are enriched in the coarse sieved fraction of bagnold sands corroborated by visible near infrared spectra that suggest enrichment of olivine collectively patterns in major element chemistry and volatile release data indicate two distinctive volatile reservoirs in martian soils 1 amorphous components in the sand sized fraction represented by bagnold that are si enriched hydroxylated alteration products and or h 2o or oh bearing impact or volcanic glasses and 2 amorphous components in the fine fraction 40 m represented by rocknest and other bright soils that are fe s and cl enriched with low si and adsorbed and structural h 2o

environmental changes during the holocene climatic optimum in central europe human impact and natural causes abstract the priority programme changes of the geo biosphere aimed to reconstruct the environmental history of central europe with emphasis on the time interval from 9000 to 5500 cal bp time slice ii coinciding with the holocene climatic optimum during this period the onset of human activities such as settlement agriculture and animal husbandry caused environmental changes studies of different landscape units in germany were carried out to identify these anthropogenically induced changes and to distinguish them from natural effects on the environmental system the investigated archives included laminated lake sediments fluvial sediments colluvia and soils speleothems peat and coastal sediments the different archives were examined using refined research methods including a variety of sedimentary and geochemical analyses together with pollen analysis and dating methods for the establishment of a reliable chronology the results of the various research groups are summarised and critically discussed based on these results the climatic optimum can be subdivided into three periods 1 the early atlantic from 9000 to 7500 cal bp with negligible human impact and stable environmental conditions 2 the late atlantic during early and middle neolithic from 7500 to 6300 cal bp with pollen evidence for vegetation changes but only negligible changes detectable in other proxy records and 3 the late atlantic during the younger neolithic jungneolithikum after 6300 cal bp with human impact observed in many archives and proxy records especially in the pollen record but also in lacustrine and fluvial sediments during the whole climatic optimum natural causes such as minor shifts of temperature did not induce substantial environmental changes though some changes such as temporary droughts may have facilitated and amplified the observed human impact

the chemcam remote micro imager at gale crater review of the first year of operations on mars abstract the mars science laboratory rover curiosity landed near the base of a 5 km high mound of layered material in gale crater mounted on the rover mast the chemcam instrument is designed to remotely determine the composition of soils and rocks located a few meters from the rover using a laser induced breakdown spectrometer libs coupled to a remote micro imager rmi we provide an overview of the diverse imaging investigations that were carried out by chemcam s rmi during the first year of operation on mars 1182 individual panchromatic rmi images were acquired from sol 10 to sol 360 to document the chemcam libs measurements and to characterize soils rocks and rover hardware we show several types of derived imaging products including mosaics of images taken before and after laser shots difference images to enhance the most subtle laser pits merges with color mastcam 100 images micro topography using the z stack technique and time lapse movies the very high spatial resolution of rmi is able to resolve rock textures at sub mm scales which provides clues regarding the origin igneous versus sedimentary of rocks and to reveal information about their diagenetic and weathering evolution in addition to its scientific value over the range accessible by libs 1 7 m we also show that rmi can also serve as a powerful long distance reconnaissance tool to characterize the landscape at distances up to several kilometers from the rover

assessment of aeolis palus stratigraphic relationships based on bench forming strata in the kylie and the kimberley regions of gale crater mars abstract the stratigraphic context of rock layers is a critical piece of information needed for accurate reconstruction of their geologic history although sedimentary rocks are widespread in gale crater efforts to deduce stratigraphic relationships of rocks were challenging early in the mars science laboratory mission because vertical bedrock exposures were relatively rare along the first 3 km the rover traversed across aeolis palus potential insights into the three dimensional configuration of rock layers were made once the rover passed dingo gap especially in the informally named kylie and kimberley regions here the terrain exhibits low relief 75 m curiosity mastcam and navcam images show that the cliffs are capped by resistant bench forming rock layers corresponding to two facies a poorly sorted weakly stratified pebble conglomerate and a massive dark toned vuggy sandstone in places the inclination of the topographic surface northward 2 to 3 is similar to the apparent dip of the underlying strata suggesting the presence of dip slopes in an area inferred to be generally flat lying conformable rock units further we assessed potential strata correlations via plane fitting exercises and a regional comparison to other capping strata we speculate that bench forming strata in the study region could be part of a widespread package of draping strata the siccar point group that post dates deposition and exhumation of the lower strata of mount sharp

simulating the decadal to millennial scale dynamics of morphology and sequestered carbon mobilization of two thermokarst lakes in nw alaska 1 thermokarst lakes alter landscape topography and hydrology in widespread permafrost regions and mobilize significant permafrost carbon pools including releasing methane ch4 to the atmosphere despite this the dynamics of lake evolution permafrost thawing and carbon mobilization are not well known we present a 3 d numerical model of thermokarst lakes on organic rich yedoma permafrost terrains with surface water flow and pooling naturally defining lakes that deepen expand laterally and drain due to talik formation bank retreat and both gradual and catastrophic drainage we predict the 3 d pattern of microbial methane production within the talik over time as a first model test and calibration beginning with small protolakes we simulated 10 000 years of evolution of pear and claudi lakes two neighboring thermokarst features on the northern seward peninsula alaska simulated lakes approximated observed bathymetry but results are sensitive to initial topography and soil ice content local topography caused markedly different dynamics for the two lakes pear expanded rapidly across low relief topography fully drained multiple times and released little methane in later stages due to pleistocene carbon depletion by the first and largest lake generation claudi grew slowly and continuously across high relief topography forming high subaerial banks partial drainages left remnant horseshoe lakes that continued to expand into virgin yedoma mobilizing carbon at roughly the same rate irrespective of lake drainage the 2 discrepancy between simulated ch4 production and observed emission rates in claudi likely results from misestimation of hot spot ebullition labile carbon content ch4 co2 production ratio or microbial ch4 oxidation

discordant k ar and young exposure dates for the windjana sandstone kimberley gale crater mars k ar and noble gas surface exposure age measurements were carried out on the windjana sandstone kimberley region gale crater mars by using the sample analysis at mars instrument on the curiosity rover the sandstone is unusually rich in sanidine as determined by chemin x ray diffraction contributing to the high k 2o concentration of 3 09 0 20 wt measured by alpha particle x ray spectrometer analysis a sandstone aliquot heated to 915 c yielded a k ar age of 627 50 ma reheating this aliquot yielded no additional ar a second aliquot heated in the same way yielded a much higher k ar age of 1710 110 ma these data suggest incomplete ar extraction from a rock with a k ar age older than 1710 ma incomplete extraction at 900 c is not surprising for a rock with a large fraction of k carried by ar retentive k feldspar likely variability in the exact temperature achieved by the sample from run to run uncertainties in sample mass estimation and possible mineral fractionation during transport and storage prior to analysis may contribute to these discrepant data cosmic ray exposure ages from 3he and 21 ne in the two aliquots are minimum values given the possibility of incomplete extraction however the general similarity between the 3he 57 49 and 18 32 ma mean 30 ma and 21 ne 2 32 and 83 24 ma mean 54 ma exposure ages provides no evidence for underextraction the implied erosion rate at the kimberley location is similar to that reported at the nearby yellowknife bay outcrop

constraining ancient magmatic evolution on mars using crystal chemistry of detrital igneous minerals in the sedimentary bradbury group gale crater mars

the relationship between major element concentration and grain size within sandstones from four turbidite sequences in japan abstract there are few systematic investigations of variation in major element concentration with varying grain size in sandstone in this study we examine the relationship between grain size and major element composition for four suites of sandstone each with different modal composition and sio2 content the sandstones are sampled from permian cretaceous and paleogene turbidite sequences in japan we found that the effect of grain size on sandstone chemistry is related to the mineral composition of the sandstone itself in commonly occurring sandstones that are composed mainly of quartz feldspar and felsic intermediate volcanic rock fragments a decrease in grain size is accompanied by a gradual decrease in sio2 content and increase in tio2 al2o3 fe2o3 mgo k2o and p2o5 the relationships can be largely explained by relative increases in the abundance of illite and chlorite in the fine grained sediments in contrast sandstones that are derived mainly from basic volcanic rocks and that contain a high proportion of mafic minerals show different major element trends in response to grain size variation in this group sio2 and k2o contents increase gradually with decreasing grain size whereas tio2 fe2o3 mgo cao and p2o5 decrease the major element trends observed in these sandstones are related to syn depositional hydraulic sorting of heavy mafic minerals from light felsic minerals such as quartz and feldspar

environmental response to climatic and volcanic events in central europe during the weichselian lateglacial this paper reviews major results of the recent german research priority program changes of the geo biosphere during the last 15 000 years a contribution to pages focussing on changes of the geo biosphere during the weichselian lateglacial different continental archives such as annually laminated lacustrine sediments floodplain sediments and speleothems were used to reconstruct environmental response to climatic changes and the laacher see eruption event at ca 12 900 cal bp special emphasis is paid to establish a reliable time control using varve counting high precision radiocarbon dating of tree ring series and ams radiocarbon dating of terrestrial plant macrofossils recovered from lacustrine sediments to correlate and synchronize large scale environmental changes and events in central europe

a paleoclimate record of the last 17 600 years in stalagmites from the b7 cave sauerland germany abstract petrographical and geochemical parameters of stalagmites from the b7 cave in iserlohn letmathe northern rhenish massif nw germany record late and postglacial climate changes temperature and or precipitation fabrics and microfacies of the stalagmite profiles lead to a differentiation of four hierarchies of rhythms clastic layers in the stalagmites are caused by flooding events and are time markers twenty four tims th u age dates provide a time calibration of stalagmite growth phases one stalagmite reveals an early growth period between 17 6 and 16 7 ka bp between 9 6 and 5 5 ka bp atlantic episode of the holocene the growth rate of the stalagmites was higher than before and after this time with dominant light porous microfacial laminae and high 18 o and 13 c values representing partly kinetic fractionation effects this part of the holocene is interpreted as a mainly warm episode with frequent interruptions of dripping within the past 4 ka the profiles with predominant dark compact facies reveal low isotopic values which may be interpreted as a temperature proxy record the stalagmite records resemble records from an irish stalagmite correlation with the 14 c record from european tree rings suggests that colder periods in the north atlantic were accompanied by drier winters in central europe

chemistry and texture of the rocks at rocknest gale crater evidence for sedimentary origin and diagenetic alteration a suite of eight rocks analyzed by the curiosity rover while it was stopped at the rocknest sand ripple shows the greatest chemical divergence of any potentially sedimentary rocks analyzed in the early part of the mission relative to average martian soil and to the stratigraphically lower units encountered as part of the yellowknife bay formation these rocks are significantly depleted in mgo with a mean of 1 3 wt and high in fe averaging over 20 wt feo t with values between 15 and 26 wt feo t the variable iron and low magnesium and rock texture make it unlikely that these are igneous rocks rock surface textures range from rough to smooth can be pitted or grooved and show various degrees of wind erosion some rocks display poorly defined layering while others seem to show possible fractures narrow vertical voids are present in rocknest 3 one of the rocks showing the strongest layering rocks in the vicinity of rocknest may have undergone some diagenesis similar to other rocks in the yellowknife bay formation as indicated by the presence of soluble calcium phases the most reasonable scenario is that fine grained sediments potentially a mixture of feldspar rich rocks from bradbury rise and normal martian soil were lithified together by an iron rich cement

the origin and implications of clay minerals from yellowknife bay gale crater mars the mars science laboratory msl rover curiosity has documented a section of fluvio lacustrine strata at yellowknife bay ykb an embayment on the floor of gale crater approximately 500 m east of the bradbury landing site x ray diffraction xrd data and evolved gas analysis ega data from the chemin and sam instruments show that two powdered mudstone samples named john klein and cumberland drilled from the sheepbed member of this succession contain up to 20 wt clay minerals a trioctahedral smectite likely a ferrian saponite is the only clay mineral phase detected in these samples smectites of the two samples exhibit different 001 spacing under the low partial pressures of h2o inside the chemin instrument relative humidity 1 smectite interlayers in john klein collapsed sometime between clay mineral formation and the time of analysis to a basal spacing of 10 a but largely remain open in the cumberland sample with a basal spacing of 13 2 a partial intercalation of cumberland smectites by metal hydroxyl groups a common process in certain pedogenic and lacustrine settings on earth is our favored explanation for these differences the relatively low abundances of olivine and enriched levels of magnetite in the sheepbed mudstone when compared with regional basalt compositions derived from orbital data suggest that clay minerals formed with magnetite in situ via aqueous alteration of olivine mass balance calculations are permissive of such a reaction moreover the sheepbed mudstone mineral assemblage is consistent with minimal inputs of detrital clay minerals from the crater walls and rim early diagenetic fabrics suggest clay mineral formation prior to lithification thermodynamic modeling indicates that the production of authigenic magnetite and saponite at surficial temperatures requires a moderate supply of oxidants allowing circum neutral ph the kinetics of olivine alteration suggest the presence of fluids for thousands to hundreds of thousands of years mineralogical evidence of the persistence of benign aqueous conditions at ykb for extended periods indicates a potentially habitable environment where life could establish itself mediated oxidation of fe 2 in olivine to fe 3 in mag

evaluation of land surfaces cleared from forests by prehistoric man in early neolithic times and the time of migrating germanic tribes edited by b frenzel special issue esf project european climate and man 3 palaoklimaforschung 8 akademie der wissenschaften under der literatur mainz european science foundation strasbourg gustav fischer stuttgart 1992 225 pp price dm 74 00 isbn 1 56081 363 6

lateglacial to late holocene landscape history derived from floodplain sediments in context to prehistoric settlement sites of the southern foreland of the harz mountains germany abstract the harz mountains are germany s northernmost low mountain range the southern foreland is characterised by a fragmentary distribution of loess and loess like deposits during prehistoric times this region was sparsely populated in contrast to the adjoining southern floodplain of the helme river which has been a favoured settlement area since the neolithic period this study focusses on the onset of human impact on the landscape and aims to reconstruct the landscape development of this peripheral prehistoric settlement area under a long term perspective lateglacial to late holocene the study is based on the sedimentological analysis of six sediment profiles from the floodplain of two small valleys the chronology of the sedimentological records is provided by 24 new ams radiocarbon ages that range from 21 7 ka bp to 0 1 ka bp three major changes in the depositional environment are observed in the sediment records representing the landscape evolution a during the lateglacial periglacial conditions prevailed and deposition and reworking of loess occurred on the slopes while in the floodplains periglacial cover beds and alternating partly gravelly layers of silts and clays were deposited b from preboreal to atlantic periods a marked rise in the groundwater table led to authigenic precipitation of carbonates in the floodplains under ameliorated climatic conditions during this phase the valleys were progressively filled by intercalated organogenic and calcareous sediments c human influence on the landscape is reflected in colluvial and alluvial deposits indicating the occurrence of human induced soil erosion and is dated prior to the beginning of the bronze age here corresponding to subboreal period during the period of the little ice age gully incision occurred probably as a result of an intensified land use in upslope areas and of high magnitude precipitation events during this period

high manganese concentrations in rocks at gale crater mars the surface of mars has long been considered a relatively oxidizing environment an idea supported by the abundance of ferric iron phases observed there however compared to iron manganese is sensitive only to high redox potential oxidants and when concentrated in rocks it provides a more specific redox indicator of aqueous environments observations from the chemcam instrument on the curiosity rover indicate abundances of manganese in and on some rock targets that are 1 2 orders of magnitude higher than previously observed on mars suggesting the presence of an as yet unidentified manganese rich phase these results show that the martian surface has at some point in time hosted much more highly oxidizing conditions than has previously been recognized

the potassic sedimentary rocks in gale crater mars as seen by chemcam on board curiosity key points mean k2o abundance in sedimentary rocks 5 times higher than that of the average martian crust presence of alkali feldspars and k phyllosilicates in basaltic sedimentary rocks along the traverse the k bearing minerals likely have a detrital origin

segregation of olivine grains in volcanic sands in iceland and implications for mars abstract basaltic sands cover several plains in volcanic regions on earth and dominate the aeolian sediments on mars but basaltic sands are not as well characterized as felsic sands the lambahraun sandy lava plain in iceland was chosen as a martian analog to study the physical sorting of basaltic sands the strong winds affecting the plain and its young age

mineralogy provenance and diagenesis of a potassic basaltic sandstone on mars chemin x ray diffraction of the windjana sample kimberley area gale crater the windjana drill sample a sandstone of the dillinger member kimberley formation gale crater mars was analyzed by chemin x ray diffraction xrd in the msl curiosity rover from rietveld refinements of its xrd pattern windjana contains the following sanidine 21 weight or95 augite 20 magnetite 12 pigeonite olivine plagioclase amorphous and smectitic material 25 and percent levels of others including ilmenite fluorapatite and bassanite from mass balance on the alpha proton x ray spectrometer apxs chemical analysis the amorphous material is fe rich with nearly no other cations like ferrihydrite the windjana sample shows little alteration and was likely cemented by its magnetite and ferrihydrite from chemcam laser induced breakdown spectrometer libs chemical analyses windjana is representative of the dillinger and mount remarkable members of the kimberley formation libs data suggest that the kimberley sediments include at least three chemical components the most k rich targets have 5 6 k2o 1 8 times that of windjana implying a sediment component with 40 sanidine e g a trachyte a second component is rich in mafic minerals with little feldspar like a shergottite a third component is richer in plagioclase and in na2o and is likely to be basaltic the k rich sediment component is consistent with apxs and chemcam observations of k rich rocks elsewhere in gale crater the source of this sediment component was likely volcanic the presence of sediment from many igneous sources in concert with curiosity s identifications of other igneous materials e g mugearite implies that the northern rim of gale crater exposes a diverse igneous complex at least as diverse as that found in similar age terranes on earth

a combined pollen and δ18osphagnum record of mid holocene climate variability from durres maar eifel germany in this study we investigate pollen and oxygen isotopes of moss cellulose from the peat bog durres maar in the eifel low mountain range germany 450 m a s l to quantitatively infer mid holocene climate change for the period between 7000 and 3800 cal bp pollen was analysed on the same samples from which sphagnum leaves were isolated to extract cellulose for the determination of its oxygen isotope composition 18osphagnum to quantitatively estimate january and july temperature and annual precipitation from the pollen data we applied a probabilistic indicator taxa method pdf method the pollen based reconstructions indicate july temperatures 1 c higher around 6000 cal bp than after 5500 cal bp which is consistent with a 1 decrease in 18osphagnum during the same period while the pollen based climate reconstructions indicate little variability in summer temperature after 5500 cal bp winter temperature shows several pronounced cold excursions of 2 4 c in this period which was likel

in situ evidence for continental crust on early mars understanding of the geologic evolution of mars has been greatly improved by recent orbital 1 3 in situ 4 5 and meteorite 6 8 data but insights into the earliest period of martian magmatism 4 1 to 3 7 billion years ago remain scarce 9 the landing site of nasa s curiosity rover gale crater which formed 3 61 billion years ago 10 within older terrain 11 provides a window into this earliest igneous history along its traverse curiosity has discovered light toned rocks that contrast with basaltic samples found in younger regions 12 here we present geochemical data and images of 22 specimens analysed by curiosity that demonstrate that these light toned materials are feldspar rich magmatic rocks the rocks belong to two distinct geochemical types alkaline compositions containing up to 67 wt sio2 and 14 wt total alkalis na2o k2o with fine grained to porphyritic textures on the one hand and coarser grained textures consistent with quartz diorite and granodiorite on the other hand our analysis reveals unexpected magmatic diversity and the widespread presence of silica and feldspar rich materials in the vicinity of the landing site at gale crater combined with the identification of feldspar rich rocks elsewhere 9 13 14 and the low average density of the crust in the martian southern hemisphere 15 we conclude that silica rich magmatic rocks may constitute a significant fraction of ancient martian crust and may be analogous to the earliest continental crust on earth

first detection of fluorine on mars implications for gale crater s geochemistry volatiles and especially halogens f and cl have been recognized as important species in the genesis and melting of planetary magmas data from the chemical camera instrument on board the mars science laboratory rover curiosity now provide the first in situ analyses of fluorine at the surface of mars two principal f bearing mineral assemblages are identified the first is associated with high aluminum and low calcium contents in which the f bearing phase is an aluminosilicate it is found in conglomerates and may indicate petrologically evolved sources this is the first time that such a petrologic environment is found on mars the second is represented by samples that have high calcium contents in which the main f bearing minerals are likely to be fluorapatites and or fluorites fluorapatites are found in some sandstone and may be detrital while fluorites are also found in the conglomerates possibly indicating low t alteration processes

comparing orbiter and rover image based mapping of an ancient sedimentary environment aeolis palus gale crater mars this study provides the first systematic comparison of orbital facies maps with detailed ground based geology observations from the mars science laboratory msl curiosity rover to examine the validity of geologic interpretations derived from orbital image data orbital facies maps were constructed for the darwin cooperstown and kimberley waypoints visited by the curiosity rover using high resolution imaging science experiment hirise images these maps which represent the most detailed orbital analysis of these areas to date were compared with rover image based geologic maps and stratigraphic columns derived from curiosity s mast camera mastcam and mars hand lens imager mahli results show that bedrock outcrops can generally be distinguished from unconsolidated surficial deposits in high resolution orbital images and that orbital facies mapping can be used to recognize geologic contacts between well exposed bedrock units however process based interpretations derived from orbital image mapping are difficult to infer without known regional context or observable paleogeomorphic indicators and layer cake models of stratigraphy derived from orbital maps oversimplify depositional relationships as revealed from a rover perspective this study also shows that fine scale orbital image based mapping of current and future mars landing sites is essential for optimizing the efficiency and science return of rover surface operations

varve chronology and palynology of the lateglacial in northwest germany from lacustrine sediments of hamelsee in lower saxony abstract the hamelsee is a dolina from a collapse over permian salt that occurred at the end of the pleniglacial it is more than 21 m deep and contains 18 m of lacustrine sediments the lateglacial sediments in the central part of the lake consist of 2 7 m from 15 to 17 7 m of sapropelic and silty muds which are mostly laminated and partly bioturbated minor slumps occur mainly during colder phases the subdivision of the lateglacial is based on pollen zones multidisciplinary studies of the microfacies from thin sections geochemistry pollen analysis and rotifer analysis allow environmental and palaeoclimatological interpretations to be made the biozones of the lateglacial and their boundaries are marked by rapid climatic changes though covering comparatively short periods of time they are not monotonous but characterized by minor internal climatic fluctuations the sediments of the meiendorf and oldest dryas are not laminated the allerod sediment is seasonally varved without interruption and encompasses 625 yr the eruption of the laacher see volcano 12 900 cal bp had an impact on the climate during the following 10 yr the transition from the allerod to the younger dryas took some 50 yr and it occurred 200 yr after the eruption of the laacher see volcano the abrupt change at the end of the lateglacial 11 560 cal bp occurred within less than 10 yr however many proxies reacted with a time lapse of 15 to 30 yr

age and source of colluvial sediments at vaihingen enz germany abstract colluvial sediments accumulated on the lower slopes of a ridge as a result of past and present soil erosion were dated by optical 14 c and archaeological methods this allowed us to reconstruct the depositional history of the colluvium and also to identify temporary sedimentary sinks in its transportational pathway a cascade model of colluvium formation is developed colluvial sediments resulting from early soil erosion in the neolithic to iron age periods were mainly deposited on the upper slopes significant deposition on the lower slope occurred for the first time during the iron age and roman period since then deposition rates have increased because of more intensive land use

potassium rich sandstones within the gale impact crater mars the apxs perspective the alpha particle x ray spectrometer apxs onboard the curiosity rover at the kimberley location within gale crater mars analyzed basaltic sandstones that are characterized by potassium enrichments of two to eight times estimates for average martian crust they are the most potassic rocks sampled on mars to date they exhibit elevated fe mg mn and zn and depleted na al and si these compositional characteristics are common to other potassic sedimentary rocks analyzed by apxs at gale but distinct from other landing sites and martian meteorites chemin and apxs analysis of a drilled sample indicate mineralogy dominated by sanidine ca rich and ca poor clinopyroxene magnetite olivine and andesine the anhydrous mineralogy of the kimberley sample and the normative mineralogy derived from apxs of other bathurst class rocks together indicate provenance from one or more potassium rich magmatic or impact generated source rocks on the rim of gale crater or beyond elevated zn ge and cu suggest that a localized area of the source region s experienced hydrothermal alteration which was subsequently eroded dispersed and diluted throughout the unaltered sediment during transport and deposition the identification of the basaltic high potassium bathurst class and other distinct rock compositional classes by the apxs attests to the diverse chemistry of crustal rocks within and in the vicinity of gale crater we conclude that weathering transport and diagenesis of the sediment did not occur in a warm and wet environment but instead under relatively cold and wet conditions perhaps more fitting with processes typical of glacial periglacial environments

fluvial history of the northern upper rhine river southwestern germany during the lateglacial and holocene times abstract three time slices were focused on reconstruction of the lateglacial and holocene landscape evolution in the northern upper rhine rift valley the fluvial history of the northern upper rhine river during the last 15 000 years is characterised by repeated rapid changes of fluvial morphodynamics and sedimentation conditions in consequence the floodplain of the rhine river may be subdivided into three different meander generations which differ mainly on morphological lithological and pedogenetical criteria using complementary dating techniques pollen irsl ams 14c a detailed chronology was obtained for the floodplain sediments e g overbank deposits peat bogs aeolian dune sands of the rhine river and its tributary the neckar river bergstrasen necker while the latter became completely abandoned during the younger dryas period the rhine river probably started meandering at the onset of the allerod period and most likely continued its meandering pattern since the lateglacial the change from the oldest meander generation to the older meander generation occurred during the late phase of the atlantic period however the timing of the onset of the younger meander generation is not known in detail at present probably it started to develop in the late subboreal period or at the transition from the subboreal to the subatlantic period

copper enrichments in the kimberley formation in gale crater mars evidence for a cu deposit at the source copper quantification with laser induced breakdown spectroscopy libs using a univariate calibration model enables the chemcam instrument onboard the curiosity rover to measure unusually elevated cu concentrations in potassic sandstones and mn oxide bearing fracture fills in the kimberley region of gale crater mars mostly the copper phases occurring in sedimentary bedrock are associated with detrital silicates including feldspars pyroxenes and k phyllosilicates likely coming from a potassic igneous source near the northern crater rim while those present in the fractures are likely adsorbed on the surface of manganese oxides these two different mineralogical associations imply at least two distinct processes cu enrichment in bedrock at the source likely during crystallization of the igneous silicates and adsorption of cu on mn oxides precipitated from groundwater that encountered oxidizing conditions within fractures in the bedrock the potassic sediments enriched in copper may be evidence of a porphyry copper deposit or an impact induced hydrothermal deposit in the source region

magmatic complexity on early mars as seen through a combination of orbital in situ and meteorite data abstract until recently mars was considered a basalt covered world but this vision is evolving thanks to new orbital in situ and meteorite observations in particular of rocks of the ancient noachian period in this contribution we summarise newly recognised compositional and mineralogical differences between older and more recent rocks and explore the geodynamic implications of these new findings for example the msl rover has discovered abundant felsic rocks close to the landing site coming from the wall of gale crater ranging from alkali basalt to trachyte in addition the recently discovered martian regolith breccia nwa 7034 and paired samples contain many coarse grained noritic monzonitic clasts demonstrably noachian in age and even some clasts that plot in the mugearite field olivine is also conspicuously lacking in these ancient samples in contrast to later hesperian rocks the alkali suite requires low degree melting of the martian mantle at low pressure whereas the later hesperian magmatism would appear to be produced by higher mantle temperatures various scenarios are proposed to explain these observations including different styles of magmatic activity i e passive upwelling vs hotspots a second petrological suite of increasing interest involves quartzo feldspathic materials that were first inferred from orbit in local patches in the southern highlands and in the lower units of valles marineris however identification of felsic rocks from orbit is limited by the low detectability of feldspar in the near infrared on the other hand the msl rover has described the texture mineralogy and composition of felsic rocks in gale crater that are granodiorite like samples akin to terrestrial ttg tonalite trondhjemite granodiorite suites these observations and the low average density of the highlands crust suggest the early formation of continental crust on mars although the details of the geodynamic scenario and the importance of volatiles in their generation are aspects that require further work

alkalic parental magmas for chassignites detailed analysis of cumulate and melt inclusion assemblages in the chassignites provide important constraints on the nature of the melt trapped as inclusions in cumulus olivine and by extension parental magma compositions the pressures of crystallization and magmatic volatile contents these mineral assemblages show strong similarities to the experimental fractionation assemblages that produce the sodic silica saturated alkalic lavas on earth e g ascension island azores the nandewar volcano of australia the experimental assemblages were produced from silica saturated hawaiite at pressures above 4 3 kbar with dissolved water contents above 0 5 wt such pressures are consistent with ti al ratios of the melt inclusion pyroxenes in the chassigny meteorite pyroxene compositions suggest early high crystallization temperatures and thus relatively low initial water and f contents feldspars indicate that melt evolution proceeded to rhyolite compositions both within the interstices of the cumulate olivine and within the melt inclusions even though rhyolitic glass is only found within olivine hosted polyphase melt inclusions the observed rhyolite glass is compositionally similar to the alkali rich rhyolite of ascension island which is produced experimentally by crystallization of hawaiite it is proposed that the melt trapped in cumulus olivine of the chassigny dunite was similar to a terrestrial silica saturated hawaiite while that trapped in olivine of the northwest africa nwa 2727 dunite was less evolved perhaps mildly alkalic basalt melts similar to terrestrial intra plate tholeiite could be parental to the cumulus minerals and evolve upon crystallization at pressures above 4 3 kbar and water contents above 0 4 wt to mildly alkalic basalt silica saturated hawaiite and alkali rich rhyolite the melt inclusion assemblages are inconsistent with either crystallization of a low al high fe basalt or low pressure crystallization of a terrestrial like tholeiite

the origin and evolution of the peace vallis fan system that drains to the curiosity landing area gale crater mars the landing site for the curiosity rover is located at the distal end of the peace vallis fan in gale crater peace vallis fan covers 80 km2 and is fed by a 730 km2 catchment which drains an upland plains area through a 15 km wide gap in the crater rim valley incision into accumulated debris delivered sediment through a relatively low density valley network to a main stem channel to the fan an estimated total fan volume of 0 9 km3 matches the calculated volume of removal due to valley incision 0 8 km3 and indicates a mean thickness of 9 m the fan profile is weakly concave up with a mean slope of 1 5 for the lower portion numerous inverted channels outcrop on the western surface of the fan but on the eastern portion such channels are rare suggesting a change in process from distributary channel domination on the west to sheet flow on the eastern portion of the fan runoff discharge watershed area to produce the fan is estimated to be more than 600 m perhaps as much as 6000 m indicating a hydrologic cycle that likely lasted at least thousands of years atmospheric precipitation possibly snow not seepage produced the runoff based on topographic data peace vallis fan likely onlapped bradbury rise and spilled into a topographic low to the east of the rise this argues that the light toned fractured terrain within this topographic low corresponds to the distal deposits of peace vallis fan and in such a setting lacustrine deposits are expected

chemcam results from the shaler outcrop in gale crater mars abstract the chemcam campaign at the fluvial sedimentary outcrop shaler resulted in observations of 28 non soil targets 26 of which included active laser induced breakdown spectroscopy libs and all of which included remote micro imager rmi images the shaler outcrop can be divided into seven facies based on grain size texture color resistance to erosion and sedimentary structures the chemcam observations cover facies 3 through 7 for all targets the majority of the grains were below the limit of the rmi resolution but many targets had a portion of resolvable grains coarser than 0 5 mm the shaler facies show significant scatter in libs spectra and compositions from point to point but several key compositional trends are apparent most notably in the average k2o content of the observed facies facies 3 is lower in k2o than the other facies and is similar in composition to the snake a clastic dike that occurs lower in the yellowknife bay stratigraphic section facies 7 is enriched in k2o relative to the other facies and shows some compositional and textural similarities to float rocks near yellowknife bay the remaining facies 4 5 and 6 are similar in composition to the sheepbed and gillespie lake members although the shaler facies have slightly elevated k2o and feot several analysis points within shaler suggest the presence of feldspars though these points have excess feot which suggests the presence of fe oxide cement or inclusions the majority of libs analyses have compositions which indicate that they are mixtures of pyroxene and feldspar the shaler feldspathic compositions are more alkaline than typical feldspars from shergottites suggesting an alkaline basaltic source region particularly for the k2o enriched facies 7 apart from possible iron oxide cement there is little evidence for chemical alteration at shaler although calcium sulfate veins comparable to those observed lower in the stratigraphic section are present the differing compositions and inferred provenances at shaler suggest compositionally heterogeneous terrain in the gale crater rim and surroundings and intermittent periods of deposition

a habitable fluvio lacustrine environment at yellowknife bay gale crater mars the curiosity rover discovered fine grained sedimentary rocks which are inferred to represent an ancient lake and preserve evidence of an environment that would have been suited to support a martian biosphere founded on chemolithoautotrophy this aqueous environment was characterized by neutral ph low salinity and variable redox states of both iron and sulfur species carbon hydrogen oxygen sulfur nitrogen and phosphorus were measured directly as key biogenic elements by inference phosphorus is assumed to have been available the environment probably had a minimum duration of hundreds to tens of thousands of years these results highlight the biological viability of fluvial lacustrine environments in the post noachian history of mars

a rover s geologic field campaign exploration of the kimberley by curiosity the mars science laboratory curiosity rover undertook comprehensive exploration of the kimberley waypoint within gale crater mars in order to understand its context within the larger geologic picture of gale crater and its evidence for past martian habitability coordinated observations from curiosity s rich science payload revealed important insights into new martian crustal compositions the prevalence and diversity of sedimentary processes within gale crater and surface erosion rates exploration at the kimberley in part informed by a decade of orbital observations of gale crater underscored the critical synergy between landed and orbital observations and furthered understanding of complex geological processes on mars

chemical variability in mineralized veins observed by chemcam on the lower slopes of mount sharp in gale crater mars chemcam has observed a wide range of diagenetic features along the curiosity rover traverse including pervasive ca sulfate veins observations by multiple instruments on curiosity indicate that these veins are hydrated formed during diagenetic fluid event s in this study we delve into the chemical variability in these ca sulfate bearing veins and have identified two subsets in the murray formation with enrichments in fe and fe mg these chemical trends do not reflect a sampling mixture with the surrounding host rock but likely indicates the presence of authigenic phases formed during the emplacement of these veins based on passive reflectance spectral analysis and correlation with other elements fe 3 oxides and or sulfates are proposed to account for the fe rich observations in the vicinity of the naukluft plateau whereas the fe mg trend is also observed in adjacent dark toned features with elevated mn and p near the old soaker outcrop the specific localization of these observations in the gale stratigraphy implies changing ph and redox conditions in the groundwater at the time of formation of these veins from oxidizing and likely more acidic near the naukluft plateau to more reducing conditions in the upper part of the murray formation

an isochemical model for formation of authigenic kaolinite k feldspar and illite in sediments abstract although thermodynamic calculations indicate a narrow range of conditions for coprecipitation of kaolinite and k feldspar coexistence of authigenic kaolinite and k feldspar is common in jurassic sandstones of the north sea this paper shows that the coexistence of authigenic k feldspar and kaolinite may indicate that this narrow range of conditions did prevail and that the system behaved as a closed system these conditions are presence of muscovite in the sediment pore waters supersaturated with respect to quartz and temperatures lower than 50 c at higher temperatures the authigenic kaolinite and authigenic k feldspar may react and form authigenic illite muscovite and quartz cement the direction of the isochemical reaction is thermodynamically determined by the degree of supersaturation with respect to quartz in the formation water published data on the degree of supersaturation with respect to quartz in formation waters suggest that the illitization of kaolinite may take place at temperatures as low as 50 c much lower than previously believed

authigenic k feldspar in the bromsgrove sandstone formation triassic of ccntral england abstract authigenic k feldspar is a ubiquitous feature of the bromsgrove sandstone formation triassic in central england it occurs mainly as partially to completely developed euhedral overgrowths on detrital k feldspar cores the authigenic k feldspar is virtually pure kalsi3o8 potassian low sanidine and occurs as optically continuous overgrowths on detrital sanidine and optically discontinuous overgrowths on detrital orthoclase differences in structure and al si disorder thus control the degree of optical continuity of the overgrowths an important feature is the presence of optically and compositionally zoned overgrowths due to minor fluctuations in the bao and na2o content the formation of the overgrowths was dependent upon intrastratal dissolution of detrital grains for a supply of potassium aluminum and silicon precipitation took place within the k2o na2o al2o3 sio2 h2o system and in association with other phases in this system the diagenetic sequence 1 illite 2 quartz 3 k feldspar 4 illite 5 kaolinite is consistent with a progressive increase in k h ratio or h4sio4 activity followed by a general decrease so that the later interstitial fluids were much depleted in k ions and kaolinite was the final phase to precipitate

chemical variations in yellowknife bay formation sedimentary rocks analyzed by chemcam on board the curiosity rover on mars the yellowknife bay formation represents a similar to 5m thick stratigraphic section of lithified fluvial and lacustrine sediments analyzed by the curiosity rover in gale crater mars previous works have mainly focused on the mudstones that were drilled by the rover at two locations the present study focuses on the sedimentary rocks stratigraphically above the mudstones by studying their chemical variations in parallel with rock textures results show that differences in composition correlate with textures and both manifest subtle but significant variations through the stratigraphic column though the chemistry of the sediments does not vary much in the lower part of the stratigraphy the variations in alkali elements indicate variations in the source material and or physical sorting as shown by the identification of alkali feldspars the sandstones contain similar relative proportions of hydrogen to the mudstones below suggesting the presence of hydrous minerals that may have contributed to their cementation slight variations in magnesium correlate with changes in textures suggesting that diagenesis through cementation and dissolution modified the initial rock composition and texture simultaneously the upper part of the stratigraphy similar to 1m thick displays rocks with different compositions suggesting a strong change in the depositional system the presence of float rocks with similar compositions found along the rover traverse suggests that some of these outcrops extend further away in the nearby hummocky plains

synchronous holocene climatic oscillations recorded on the swiss plateau and at timberline in the alps eight synchronous pre roman cold phases were found at 9600 9200 8600 8150 7550 6900 6600 6200 5350 4900 4600 4400 3500 3200 and 2600 2350 radiocarbon years bp by reconstructing past climate at two sites on the swiss plateau and at timberline in the alps the cooling events during the early and mid holocene represent temperature values similar to today and apparently the onset of cooling events represents a deviation from today s mean annual temperature of about 1 c and is triggered at a 1000 year periodicity at wallisellen langachermoos 440 m a former oligotrophic lake near zurich the correlation between sum mertime lake levels and the seed production of the amphi atlantic aquatic plantnajas flexilis was used to reconstruct lake levels over a 3000 year period during the first part of the holocene at lake seedorf on the western swiss plateau 609 m the sedimentological palynological and macrofossil record revealed fluctuations of lake levels for the complete holocene from lago basso in the

late and post glacial evolution of lake steisslingen i abstract piston cores from lake steisslingen a small hard water lake situated 20 km west of lake constance and mainly supplied by submerged springs reveal a record of the environmental history going back to 15 600 cal yr bp from the bolling to ca 9800 cal yr bp the sediments are partly seasonally laminated from then on up to the middle ages the lamination is mostly undisturbed providing a high resolution time scale by varve counting a detailed pollen profile and 13 ams 14c analyses all investigated sediment sections show evidence of exceptionally high sulphate concentrations in the lake water which lead to the fixation of all reactive iron as pyrite the high sulphur content can only be attributed to s rich water supplied by the submerged springs thus indicating the miocene obere meeres molasse as the dominant aquifer since soil erosion is strongly reduced due to increased forest density in the preboreal boreal the submerged springs are the main nutrient source for the lake mixing or stable stratification of the waterbody mostly depends on nutrient availability and bioproductivity in the epilimnion the controlling external factors are wind and changes in water level and or temperature at the end of the younger dryas and during the preboreal low water levels and precipitation rates are assumed the water column mixing was regular bioproductivity high and high degradation activity of organic matter led to a redissolution of calcite the hydrological separation of a northern shallow lake seeried probably fell into the period of this low lake level around 10 450 10 300 cal yr bp the lake level rose but never again reached the former level between 10 000 and 7200 cal yr bp non glacial varves are even found in shallower parts of the lake indicating a stable anoxic monimolimnion with a rising chemocline bioproductivity was low wind protection provided by the now dense forestation and favourable climatic conditions e g high summer temperatures and low winter temperatures seem to be the responsible factors fluctuating human impact is identified from about 7400 cal yr bp until permanent settlement by the alemanni about 1500 cal yr bp strong human influence is observed from 2000 cal yr bp onwards when agricultural activity and clearing of the shoreline vegetation by man caused high soil erosion rates and thus eutrophication at about 800 cal yr bp the recent hydrological conditions were established by implementing an artificial drain thus lowering the lake level

environmental change and fluvial activity during the younger dryas in central germany abstract late pleistocene climatically induced environmental changes are reconstructed by applying a multidisciplinary approach on floodplain sediments of small to medium sized catchments in central germany radiocarbon dating pollen analysis and the presence of an accurately dated tephra layer allow the establishment of a reliable chronology the beginning of the younger dryas is marked by a change in fluvial activity that lasts for several hundred years during this period gravels and sands were deposited by a braided river system fluvial systems at this time were predominantly controlled by the climatic conditions of the surrounding uplands where the climatic deterioration led to a lowering of the forest limit and enhanced periglacial slope processes an open pine forest prevailed in the basin areas and no evidence of slope wash and solifluction was found the second part of the younger dryas is characterised by a meandering fluvial system and the deposition of overbank fines the rapid transition from younger dryas to preboreal coincides with an increase in organic deposition

petrography and composition of martian regolith breccia meteorite northwest africa 7475 the northwest africa nwa 7475 meteorite is one of the several stones of paired regolith breccias from mars based on petrography oxygen isotope mineral compositions and bulk rock compositions its inventory of lithic clasts is dominated by vitrophyre impact melts that were emplaced while they were still molten other clast types include crystallized impact melt rocks evolved plutonic rocks possible basalts contact metamorphosed rocks and siltstones impact spherules and vitrophyre shards record airborne transport and accreted dust rims were sintered on most clasts presumably during residence in an ejecta plume the clast assemblage records at least three impact events one that formed an impact melt sheet on mars 4 4 ga ago a second that assembled nwa 7475 from impactites associated with the impact melt sheet at 1 7 1 4 ga and a third that launched nwa 7475 from mars 5 ma ago mildly shocked pyroxene and plagioclase constrain shock metamorphic conditions during launch to 5 and 15 gpa the mild postshock heating that resulted from these shock pressures would have been insufficient to sterilize this water bearing lithology during launch magnetite maghemite and pyrite are likely products of secondary alteration on mars textural relationships suggest that calcium carbonate and goethite are probably of terrestrial origin yet trace element chemistry indicates relatively low terrestrial alteration comparison of mars odyssey gamma ray spectrometer data with the fe and th abundances of nwa 7475 points to a provenance in the ancient southern highlands of mars gratteri crater with an age of 5 ma and an apparent diameter of 6 9 km marks one possible launch site of nwa 7475

geologic overview of the mars science laboratory rover mission at the kimberley gale crater mars the mars science laboratory msl curiosity rover completed a detailed investigation at the kimberley waypoint within gale crater from sols 571 634 using its full science instrument payload from orbital images examined early in the curiosity mission the kimberley region had been identified as a high priority science target based on its clear stratigraphic relationships in a layered sedimentary sequence that had been exposed by differential erosion observations of the stratigraphic sequence at the kimberley made by curiosity are consistent with deposition in a prograding fluvio deltaic system during the late noachian to early hesperian prior to the existence of most of mt sharp geochemical and mineralogic analyses suggest that sediment deposition likely took place under cold conditions with relatively low water to rock ratios based on elevated k 2o abundances throughout the kimberley formation an alkali feldspar protolith is likely one of several igneous sources from which the sediments were derived after deposition the rocks underwent multiple episodes of diagenetic alteration with different aqueous chemistries and redox conditions as evidenced by the presence of ca sulfate veins mn oxide fracture fills and erosion resistant nodules more recently the kimberley has been subject to significant aeolian abrasion and removal of sediments to create modern topography that slopes away from mt sharp a process that has continued to the present day

oxidation of manganese in an ancient aquifer kimberley formation gale crater mars the curiosity rover observed high mn abundances 25 wt mno in fracture filling materials that crosscut sandstones in the kimberley region of gale crater mars the correlation between mn and trace metal abundances plus the lack of correlation between mn and elements such as s cl and c reveals that these deposits are mn oxides rather than evaporites or other salts on earth environments that concentrate mn and deposit mn minerals require water and highly oxidizing conditions hence these findings suggest that similar processes occurred on mars based on the strong association between mn oxide deposition and evolving atmospheric dioxygen levels on earth the presence of these mn phases on mars suggests that there was more abundant molecular oxygen within the atmosphere and some groundwaters of ancient mars than in the present day

fluvial responses to climate and sea level change a review and look forward summary fluvial landforms and deposits provide one of the most readily studied quaternary continental records and alluvial strata represent an important component in most ancient continental interior and continental margin successions moreover studies of the long term dynamics of fluvial systems and their responses to external or allogenic controls can play important roles in research concerning both global change and sequence stratigraphy as well as in studies of the dynamic interactions between tectonic activity and surface processes these themes were energized in the final decades of the twentieth century and may become increasingly important in the first decades of this millennium this review paper provides a historical perspective on the development of ideas in the fields of geomorphology quaternary geology vs sedimentary geology and then summarizes key processes that operate to produce alluvial stratigraphic records over time scales of 103 106 years of particular interest are changes in discharge regimes sediment supply and sediment storage en route from source terrains to sedimentary basins as well as changes in sea level and the concept of accommodation late quaternary stratigraphic records from the loire france mississippi usa colorado texas usa and rhine meuse the netherlands rivers are used to illustrate the influences of climate change on continental interior rivers as well as the influence of interacting climate and sea level change on continental margin systems the paper concludes with a look forward to a bright future for studies of fluvial response to climate and sea level change at present empirical field based research on fluvial response to climate and sea level change lags behind a the global change community s understanding of the magnitude and frequency of climate and sea level change b the sequence stratigraphic community s desire to interpret climate and especially sea level change as forcing mechanisms and c the modelling community s ability to generate numerical and physical models of surface processes and their stratigraphic results a major challenge for the future is to catch up which will require the development of more detailed and sophisticated quaternary stratigraphic sedimentological and geochronological frameworks in a variety of continental interior and continental margin settings there is a particular need for studies that seek to document fluvial responses to allogenic forcing over both shorter 102 103 years and longer 104 106 years time scales than has commonly been the case to date as well as in larger river systems from source to sink studies of quaternary systems in depositional basin settings are especially critical because they can provide realistic analogues for interpretation of the pre quaternary rock record

observation of 5 wt zinc at the kimberley outcrop gale crater mars zinc enriched targets have been detected at the kimberley formation gale crater mars using the chemistry camera chemcam instrument the zn content is analyzed with a univariate calibration based on the 481 2 nm emission line the limit of quantification for zno is 3 wt at 95 confidence level and 1 wt at 68 confidence level the limit of detection is shown to be around 0 5 wt as of sol 950 12 targets on mars present high zno content ranging from 1 0 wt to 8 4 wt yarrada sol 628 those zn enriched targets are almost entirely located at the dillinger member of the kimberley formation where high mn and alkali contents were also detected probably in different phases zn enrichment does not depend on the textures of the rocks coarse grained sandstones pebbly conglomerates and resistant fins the lack of sulfur enhancement suggests that zn is not present in the sphalerite phase zn appears somewhat correlated with na2o and the chemcam hydration index suggesting that it could be in an amorphous clay phase such as sauconite on earth such an enrichment would be consistent with a supergene alteration of a sphalerite gossan cap in a primary siliciclastic bedrock or a possible hypogene nonsulfide zinc deposition where zn fe mn would have been transported in a reduced sulfur poor fluid and precipitated rapidly in the form of oxides

martian fluvial conglomerates at gale crater observations by the mars science laboratory mast camera mastcam in gale crater reveal isolated outcrops of cemented pebbles 2 to 40 millimeters in diameter and sand grains with textures typical of fluvial sedimentary conglomerates rounded pebbles in the conglomerates indicate substantial fluvial abrasion chemcam emission spectra at one outcrop show a predominantly feldspathic composition consistent with minimal aqueous alteration of sediments sediment was mobilized in ancient water flows that likely exceeded the threshold conditions depth 0 03 to 0 9 meter average velocity 0 20 to 0 75 meter per second required to transport the pebbles climate conditions at the time sediment was transported must have differed substantially from the cold hyper arid modern environment to permit aqueous flows across several kilometers

hydrogen detection with chemcam at gale crater abstract one of the main advantages of chemcam s libs laser induced breakdown spectroscopy instrument onboard the curiosity rover is its potential to detect light elements such as hydrogen at fine scales which has never been achieved on mars hydrogen lines are detected in most of the data obtained within the first 320 sols of the mission at gale crater mars this work is a description of the hydrogen signal and its variability in the chemcam libs spectra it discusses the challenges of qualitative and quantitative analysis data acquisition and processing steps are investigated and optimized for the detection of hydrogen on mars subtraction of an appropriate dark spectrum and the deconvolution of the superimposed emission of carbon from the low pressure co2 dominated atmosphere are particularly important because the intensities of hydrogen are also affected by matrix effects the hydrogen signal was investigated within groups of targets sharing common chemical features and similar matrices the different groups cover a variety of rock and soil compositions encountered along the traverse calcium sulfate veins mafic soils felsic mg rich and fe rich rocks including data from both drill holes and their tailings almost all these targets were found to be hydrated to variable extents soils have systematically higher hydrogen signals than rocks and pebbles probably as a result of their alteration the results from rocks suggest that various alteration processes leading to their hydration have taken place which is consistent with the fluvial lacustrine context the diagenetic features and the mineralogy observed by curiosity in yellowknife bay

geochemical diversity in first rocks examined by the curiosity rover in gale crater evidence for and significance of an alkali and volatile rich igneous source the first four rocks examined by the mars science laboratory alpha particle x ray spectrometer indicate that curiosity landed in a lithologically diverse region of mars these rocks collectively dubbed the bradbury assemblage were studied along an eastward traverse sols 46 102 compositions range from na and al rich mugearite jake matijevic to fe mg and zn rich alkali rich basalt hawaiite bathurst inlet and span nearly the entire range in feo and mno of the data sets from previous martian missions and martian meteorites the bradbury assemblage is also enriched in k and moderately volatile metals zn and ge these elements do not correlate with cl or s suggesting that they are associated with the rocks themselves and not with salt rich coatings three out of the four bradbury rocks plot along a line in elemental variation diagrams suggesting mixing between al rich and fe rich components chemcam analyses give insight to their degree of chemical heterogeneity and grain size variations in trace elements detected by chemcam suggest chemical weathering li and concentration in mineral phases e g rb and sr in feldspars we interpret the bradbury assemblage to be broadly volcanic and or volcaniclastic derived either from near the gale crater rim and transported by the peace vallis fan network or from a local volcanic source within gale crater high fe and fe mn in et then likely reflect secondary precipitation of fe 3 oxides as a cement or rind the k rich signature of the bradbury assemblage if igneous in origin may have formed by small degrees of partial melting of metasomatized mantle

elemental geochemistry of sedimentary rocks at yellowknife bay gale crater mars sedimentary rocks examined by the curiosity rover at yellowknife bay mars were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts no evidence of chemical weathering is preserved indicating arid possibly cold paleoclimates and rapid erosion and deposition the absence of predicted geochemical variations indicates that magnetite and phyllosilicates formed by diagenesis under low temperature circumneutral ph rock dominated aqueous conditions analyses of diagenetic features including concretions raised ridges and fractures at high spatial resolution indicate that they are composed of iron and halogen rich components magnesium iron chlorine rich components and hydrated calcium sulfates respectively composition of a cross cutting dike like feature is consistent with sedimentary intrusion the geochemistry of these sedimentary rocks provides further evidence for diverse depositional and diagenetic sedimentary environments during the early history of mars

chemical alteration of fine grained sedimentary rocks at gale crater abstract from sol 750 to 1550 the curiosity rover documented 100 m thick stack of fine grained sedimentary rocks making up part of the murray formation at the base of mt sharp gale crater here we use data collected by the chemcam instrument to estimate the level of chemical weathering in these sedimentary rocks both the chemical index of alteration cia and the weathering index scale wis indicate a progressive increase in alteration up section reaching values of cia of 63 and wis of 25 the increase in cia and wis values is coupled with a decrease in calcium abundance suggesting partial dissolution of ca bearing minerals clinopyroxene and plagioclase mineralogy from the chemin x ray diffraction instrument indicates a decrease in mafic minerals compared with previously analyzed strata and a significant proportion of phyllosilicates consistent with this interpretation these observations suggest that the sediments were predominantly altered in an open system before or during their emplacement contrasting with the rock dominated conditions inferred in sedimentary deposits analyzed at yellowknife bay

a 15 000 year stable isotope record from sediments of lake steisslingen southwest germany abstract stable isotope records for carbon and oxygen in bulk carbonates carbon in bulk organic matter and for total and chromium reducible sulfur in a lacustrine sediment core from lake steisslingen southwest germany show several distinct and abrupt shifts during the last 15 000 years variations in the isotopic composition of authigenic carbonates indicate two major phases in the lake history in the pre holocene the hydrological budget of the lake was apparently stable variations of 18 o values of authigenic carbonates were therefore dominantly controlled by temperature changes a decrease in the 18 o carb values of about 2 at the allerod younger dryas transition is interpreted as a drop in mean annual air temperatures of approximately 5 c an abrupt temperature increase of a similar magnitude is inferred at the younger dryas preboreal boundary throughout most of the holocene the isotopic composition of authigenic carbonates was influenced by marked changes in the hydrological budget of the lake a major positive excursion in the 13 c carb and 18 o carb values at the beginning of the atlantic and a smaller one in the preboreal were related to evaporation effects which indicate that dry climatic conditions must have prevailed at that time a simultaneous increase in 13 c values of bulk organic matter at the beginning of the atlantic suggests a high level of productivity in the lake as a consequence aqueous sulfate became limited as indicated by variations in the 34 s values of total and chromium reducible sedimentary sulfur therefore we conclude that the beginning of the atlantic was characterized not only by dry but also by warm climatic conditions which triggered a higher productivity in the lake in the subatlantic sediments large variations in carbon oxygen and sulfur isotope ratios were observed as a result of human activities causing considerable perturbations in the biogeochemical element cycling of lake steisslingen results obtained by the study of the continuous 15 ka record of lake steisslingen document clearly that isotopic proxy data from lacustrine sediments can provide useful information on environmental and climatic changes of local regional and in the case of the younger dryas event of even hemispherical significance

mineralogy of a mudstone at yellowknife bay gale crater mars sedimentary rocks at yellowknife bay gale crater on mars include mudstone sampled by the curiosity rover the samples john klein and cumberland contain detrital basaltic minerals calcium sulfates iron oxide or hydroxides iron sulfides amorphous material and trioctahedral smectites the john klein smectite has basal spacing of similar to 10 angstroms indicating little interlayer hydration the cumberland smectite has basal spacing at both similar to 13 2 and similar to 10 angstroms the larger spacing suggests a partially chloritized interlayer or interlayer magnesium or calcium facilitating h2o retention basaltic minerals in the mudstone are similar to those in nearby eolian deposits however the mudstone has far less fe forsterite possibly lost with formation of smectite plus magnetite late noachian early hesperian or younger age indicates that clay mineral formation on mars extended beyond noachian time

classification of igneous rocks analyzed by chemcam at gale crater mars abstract several recent studies have revealed that mars is not a simple basalt covered planet but has a more complex geological history in gale crater on mars the curiosity rover discovered 59 igneous rocks this paper focuses on their textures acquired from the cameras such as mahli and mastcam and their geochemical compositions that have been obtained using the chemcam instrument light toned crystals have been observed in most of the rocks they correspond to feldspars ranging from andesines oligoclases to anorthoclases and sanidines in the leucocratic vesiculated rocks darker crystals observed in all igneous rocks except the leucocratic vesiculated ones were analyzed by libs and mainly identified as fe rich pigeonites and fe augites iron oxides have been observed in all groups whereas f bearing minerals have been detected only in few of them from their textural analysis and their whole rock compositions all these 59 igneous rocks have been classified in five different groups from primitive rocks i e dark aphanitic basalts basanites trachybasalts tephrites and fine coarse grained gabbros norites to more evolved materials i e porphyritic trachyandesites leucocratic trachytes and quartz diorites the basalts and gabbros are found all along the traverse of the rover whereas the felsic rocks are located before the kimberley formation i e close to the peace vallis alluvial fan deposits this suggests that these alkali rocks have been transported by fluvial activity and could come from the northern rim of the crater and may correspond to deeper strata buried under basaltic regolith sautter et al 2015 some of the basaltic igneous rocks are surprisingly enriched in iron presenting low mg similar to the nakhlite parental melt that cannot be produced by direct melting of the dreibus and wanke 1986 martian primitive mantle the basaltic rocks at gale are thus different from gusev basalts they could originate from different mantle reservoirs or they could have undergone a more extensive fractional crystallization gale basaltic rocks could have been the parental magma of residual liquid extending into alkali field towards trachyte composition as magma fractionated under anhydrous condition on its way to the surface before sub adiabatic ascent

composition of conglomerates analyzed by the curiosity rover implications for gale crater crust and sediment sources the curiosity rover has analyzed various detrital sedimentary rocks at gale crater among which fluvial and lacustrine rocks are predominant conglomerates correspond both to the coarsest sediments analyzed and the least modified by chemical alteration enabling us to link their chemistry to that of source rocks on the gale crater rims in this study we report the results of six conglomerate targets analyzed by alpha particle x ray spectrometer and 40 analyzed by chemcam the bulk chemistry derived by both instruments suggests two distinct end members for the conglomerate compositions the first group darwin type is typical of conglomerates analyzed before sol 540 it has a felsic alkali rich composition with a na2o k2o 5 the second group kimberley type is typical of conglomerates analyzed between sols 540 and 670 in the vicinity of the kimberley waypoint it has an alkali rich potassic composition with na2o k2o 2 the variety of chemistry and igneous textures when identifiable of individual clasts suggest that each conglomerate type is a mixture of multiple source rocks conglomerate compositions are in agreement with most of the felsic alkali rich float rock compositions analyzed in the hummocky plains the average composition of conglomerates can be taken as a proxy of the average igneous crust composition at gale crater differences between the composition of conglomerates and that of finer grained detrital sediments analyzed by the rover suggest modifications by diagenetic processes especially for mg enrichments in fine grained rocks physical sorting and mixing with finer grained material of different composition

the black floodplain soil in the amoneburger becken germany a lower holocene marker horizon and indicator of an upper atlantic to subboreal dry period in central europe abstract in many sediment profiles of central european floodplains a black horizon is found between late glacial and middle to upper holocene sediments this horizon is rich in clay and humic material and is referred to as black floodplain soil bfs its widespread occurrence in the amoneburger becken near marburg hessen provides some new insights into the period and circumstances of its development as a polygenetic formation the bfs is of special importance for paleoecological and archeological research it was probably supplied with clay and humic substances from the surrounding terrestrial chernozemic soils and therefore it also has to be regarded as a sediment it developed mainly in the boreal and atlantic periods but did not gain its final characteristics until a following dry period which led to a lowering of the ground water table and widespread illuviation in the floodplains even in former lacustrine deposits

the alps with little ice evidence for eight holocene phases of reduced glacier extent in the central swiss alps glacially deformed pieces of wood organic lake sediments and clasts of reworked peat have been collected in front of alpine glaciers since ad 1990 the palaeoglaciological interpretation of these organic materials is related to earlier phases of glacier recession surpassing that of today s shrunken glaciers and to tree growth and peat accumulation in the valleys now occupied by the glaciers glacial transport of the material is indicated by wood anatomy incorporated silt sand and gravel particles missing bark and deformed treerings a total of 65 samples have been radiocarbon dated so far and clusters of dates provide evidence of eight phases of glacier recession 9910 9550 9010 7980 7250 6500 6170 5950 5290 3870 3640 3360 2740 2620 and 1530 1170 calibrated years bp allowing for the timelag between climatic fluctuations glacier response and vegetation colonization these recession phases may lag behind climatic changes by 100 200 years

ancient plutonic processes on mars inferred from the detection of possible anorthositic terrains the formation of the silicate mineral anorthosite is thought to require magmatic processes that are not expected on mars because of its predominately mafic terrains localized spectral detections by the mars reconnaissance orbiter are consistent with anorthosite suggestive of ancient intrusive igneous processes similar to those active on earth

the central uplift of ritchey crater mars abstract ritchey crater is a 79 km diameter complex crater near the boundary between hesperian ridged plains and noachian highland terrain on mars 28 8 s 309 0 e that formed after the noachian high resolution imaging science experiment hirise images of the central peak reveal fractured massive bedrock and megabreccia with large clasts compact reconnaissance imaging spectrometer for mars crism spectral analysis reveals low calcium pyroxene lcp olivine ol hydrated silicates phyllosilicates and a possible identification of plagioclase bedrock we mapped the ritchey crater central uplift into ten units with 4 main groups from oldest and originally deepest to youngest 1 megabreccia with large clasts rich in lcp and ol and with alteration to phyllosilicates 2 massive bedrock with bright and dark regions rich in lcp or ol respectively 3 lcp and ol rich impactites draped over the central uplift and 4 aeolian deposits we interpret the primitive martian crust as igneous rocks rich in lcp ol and probably plagioclase as previously observed in eastern valles marineris we do not observe high calcium pyroxene hcp rich bedrock as seen in argyre or western valles marineris the association of phyllosilicates with deep megabreccia could be from impact induced alteration either as a result of the richey impact or alteration of pre existing impactites from argyre basin and other large impacts that preceded the ritchey impact or both

influence of late glacial climate changes on sediment transport in the river werra thuringia germany abstract several sedimentary records of floodplain sediments in the werra valley and subcatchments have been analysed in order to investigate the influence of climate change on the sediment transport system in the sedimentary records of the subcatchments a marked change from minerogenic to organic sediments is visible about 14 6 ka b p according to palynological analyses this change occurs in a period with a remarkable rise in arboreal pollen percentages in addition a reverse change from organic to clastic sediments takes place shortly after 12 9 ka b p coincident with a decrease in arboreal pollen percentages during this period assuming that changes in vegetation cover are mainly caused by climate the variations in the sedimentary records are also attributed to these climatic oscillations in contrast to the subcatchments comparable changes in the sedimentary record are not detectable in the floodplain of the werra river this points to the conclusion that the influence of late glacial climate fluctuations on the sedimentary regime of a river with a relatively large and a more heterogeneous catchment seems less pronounced