propagation of tropospheric gravity waves into the upper atmosphere of mars we study the propagation of gravity waves in the martian atmosphere using a linearized one dimensional full wave model calculations are carried out for atmospheric parameters characteristic of mars orbiter laser altimeter on mars global surveyor mgs observations of apparent gravity waves in high latitude clouds and mgs radio occultation measurements of temperature variations with height suggestive of gravity wave activity waves that reach the thermosphere produce fluctuations in density comparable in amplitude with the density variations detected in mars odyssey aerobraking data gravity waves of modest amplitude are found to deposit momentum and generate significant heating and cooling in the martian atmosphere the largest heating and cooling effects occur in the thermosphere at altitudes between about 130 and 150 km with heating occurring at the lower altitudes and cooling taking place above

the bangudae petroglyph in ulsan korea studies on weathering damage and risk prognosis the prehistoric bangudae petroglyph in the ulsan area represents an outstanding national treasure of the republic of korea since the construction of the sayeon dam the petroglyph with about two hundred carvings is periodically submerged by the sayeon reservoir the danger of increasing damage has resulted in intensive efforts to protect this cultural heritage diagnosis and risk prognosis studies were carried out results of petrographical studies monument mapping and in situ measurements are presented types degree and zonation of damage are evaluated the risk estimation derived from the studies confirms the necessity of preservation measures

late archaean terrane accretion in the godthab region southern west greenland tectono stratigraphic terranes fault bounded blocks of the earth s crust characterized by a geological history distinct from that of adjacent terranes1 are now widely recognized in phanerozoic and proterozoic orogenic belts and their present configurations are thought to result from plate tectonic processes similar to those in operation today2 4 there has been much debate about whether such processes operated in archaean times5 6 here we present new data from the archaean high grade gneiss complex of the godthab now nuuk region of southern west greenland which show that discrete tectonic units recognized in the south of the region7 can be more widely identified at least four terranes are recognized each of which evolved separately until their juxtaposition in the late archaean this suggests that at least some archaean high grade gneiss complexes may resemble more recent orogenic belts formed by plate tectonic processes

possible effects of breaking gravity waves on the circulation of the middle atmosphere of mars a simplified quasi geostrophic beta plane dynamical model of the zonal mean flow is used to investigate the possible effects of breaking internal gravity waves on the circulation in the middle atmospheric region 10 100 km altitude of mars the gravity wave parameterization employed is basically the saturation parameterization of lindzen 1981 which has been utilized in several terrestrial modeling studies numerical simulations are performed for a range of plausible values of the gravity wave parameters and for different representations of the mean flow thermal forcing with a focus on the effects of topographically forced stationary gravity waves on the winter hemisphere circulation the results of the model simulations show that breaking gravity waves of intermediate horizontal scales 100 1000 km wavelengths could act to close off the winter westerly circumpolar jet in the 40 80 km altitude region and induce strong high latitude warming at these levels the latter could explain recent thermal measurements indicating that martian winter polar latitudes may be very warm far above radiative equilibrium in this middle atmospheric region deming et al 1986 for the most plausible range of parameter values breaking gravity waves do not induce much warming below 40 km consistent with available data showing that winter high latitudes are normally very cold at lower levels several dust storm cases indicate that breaking gravity waves possibly could act to induce a very large polar warming at relatively low altitudes such as was observed during the 1977 winter solstice dust storm however quite large gravity wave amplitudes and or relatively long horizontal wavelengths are required for such strong low level effects thermal forcing associated with dust heating might be a source for such anomalous gravity wave activity during a global dust storm summer simulations indicate that breaking gravity waves might alter the mean flow at somewhat higher levels than in the winter hemisphere as a consequence of the presence of westerlies in the lower atmosphere this could explain the presence of a warm summer pole in the recent 50 80 km thermal measurements of deming et al several aspects of the results relating to the middle atmospheric circulation and the polar warming phenomenon are discussed the possible importance of breaking gravity waves for constituent transports in the middle atmosphere of mars is also briefly considered

correlating p wave velocity with the physico mechanical properties of different rocks in mining and civil engineering projects physico mechanical properties of the rock affect both the project design and the construction operation determination of various physico mechanical properties of rocks is expensive and time consuming and sometimes it is very difficult to get cores to perform direct tests to evaluate the rock mass the purpose of this work is to investigate the relationships between the different physico mechanical properties of the various rock types with the p wave velocity measurement of p wave velocity is relatively cheap non destructive and easy to carry out in this study representative rock mass samples of igneous sedimentary and metamorphic rocks were collected from the different locations of india to obtain an empirical relation between p wave velocity and uniaxial compressive strength tensile strength punch shear density slake durability index young s modulus poisson s ratio impact strength index and schmidt hammer rebound number a very strong correlation was found between the p wave velocity and different physico mechanical properties of various rock types with very high coefficients of determination to check the sensitivity of the empirical equations students t test was also performed which confirmed the validity of the proposed correlations

critical degree of saturation a control factor of freeze thaw damage of porous limestones at castle of chambord france abstract the paper analyzes the petrophysical and mechanical properties of two porous limestones that were used in the construction and restoration works at the castle of chambord in france a unesco world heritage site the original construction material the tuffeau limestone with a total porosity of 45 0 6 and the replacement stone of later restorations the richemont limestone with a total porosity of 29 0 7 were subjected to freeze thaw tests under laboratory conditions to evaluate the role of critical degree of saturation and pore size distribution in frost damage laboratory tests were coupled with in situ measurements of temperature and relative humidity at stone surface at the castle of chambord in situ data show that the stones in the castle experienced several freezing thawing cycles annually the limestone samples under laboratory conditions were subjected to up to 50 freeze thaw cycles under eight different degrees of saturations the total porosity tensile strength ultrasonic pulse velocity the mercury intrusion porosimetry and scanning electron microscopy techniques were employed to analyze the conditions of samples during the cycles the experimental results show that when the degree of saturation of the two studied limestones exceeds 80 85 the freeze thaw damage occurs even after a few freeze thaw cycles the effect of freezing is very fast if the water saturation is sufficient moreover results indicate that these stones have the same critical degree of saturation of about 85 despite the differences in porosity finally the results indicate that the increase in the number of freezing thawing cycles has no effect on the critical degree of saturation but the frost damage is mostly controlled by pore size distribution rather than by total porosity accordingly critical degree of saturation can be defined as an intrinsic stone property

mars global surveyor and mars odyssey accelerometer observations of the martian upper atmosphere during aerobraking 1 mars global surveyor and mars odyssey accelerometer measurements of martian upper atmospheric densities reveal the large scale and small scale structure of the thermosphere in unprecedented detail meridional density gradients which are seasonally dependent are greater on the dayside than the nightside indicating stronger meridional winds on the dayside density scale heights do not vary greatly with latitude densities and density scale heights are lower on the nightside than on the dayside but the day night contrast is not as great as at venus thus atmospheric circulation plays a greater role in determining the state of the thermosphere on mars than on venus oscillations in density along individual density profiles probably due to gravity waves are common and their amplitudes are tens of percent step like changes in density are also observed but their origin is less clear data coverage is extensive enough to permit studies of weather not just climate

numerical simulation of the winter polar wave clouds observed by mars global surveyor mars orbiter laser altimeter abstract in 1998 the mars orbiter laser altimeter revealed the presence of isolated or quasi periodic thick clouds during the martian polar night they are believed to be composed of co 2 ice particles and to be tilted against the wind direction a feature characteristic of vertically propagating orographic gravity waves to support that interpretation we present here numerical simulations with a two dimensional anelastic model of stratified shear flow that includes simple co 2 ice microphysics in some of the simulations presented the orography is an idealized trough with dimensions characteristic of the many troughs that shape the mars polar cap in others it is near the real orography in the polar night conditions our model shows that gravity waves over the north polar cap are strong enough to induce adiabatic cooling below the co 2 frost point from this cooling airborne heterogeneous nucleation of co 2 ice particles occurs from the ground up to the altitude of the polar thermal inversion although the model predicts that clouds can be present above 15 km only low altitude clouds can backscatter the laser beams of mola at a detectable level accordingly the shape of the laser echoes is related to the shape of the clouds at low level but do not necessarily coincide with the top of the clouds the model helps to interpret the cloud patterns observed by mola above an isolated orographic trough an isolated extended sloping cloud tilted against the wind is obtained the model shows that the observed quasi periodic clouds are due to the succession of small scale topographic features rather than to the presence of resonant trapped lee waves indeed the co 2 condensation greatly damps the buoyancy force essential for the maintenance of gravity waves far from their sources simulations with realistic topography profiles show the cloud response is sensitive to the wind direction when the wind is directed upslope of the polar cap on the one hand a large scale cloud modulated by small scale waves forms just above the ground on the other hand when the wind is directed downslope air is globally warmed and periodic ice clouds induced by small scale orography form at altitudes higher than 3 5 km above the ground in both cases a good agreement between the simulated echoes and the observed one is obtained according to our model we conclude that the observed clouds are quasi stationary clouds made of moving ice particles that successively grow and sublimate by crossing cold and warm phases of orographic gravity waves generated by the successive polar troughs we also find that the rate of ice precipitation is relatively weak except when there is a large scale air dynamical cooling

tourmaline in the early archaean isua supracrustal belt west greenland in the early archaean isua supracrustal rocks in west greenland tourmaline is found either as stratabound occurrences in conglomerates and impure dolomites or as a tourmaline rich inclusion this inclusion which is approximately 60 tourmaline occurs as a fragment in metapelite and was presumably derived from pre isua rocks an evaporitic sabkha origin is suggested for the stratabound tourmaline whereas the tourmaline rich inclusion is believed to be of submarine exhalative origin

correlating static properties of coal measures rocks with p wave velocity physico mechanical properties of rocks are important in the planning design and stability of civil and mining engineering projects the determination of these properties in laboratory is a time consuming and laborious job and needs costly equipment and expertise but the determination of p wave velocity in laboratory as well as in in situ condition is an easy simple reliable and less complicated task so in this paper an attempt has been made to correlate physico mechanical properties of coal measures rocks with p wave velocity samples of coal shale and sandstone has been taken from the four different coal mines of india for the determination of compressive strength tensile strength shear strength density young s modulus poisson s ratio and p wave velocity

relationships between the petrographic physical and mechanical characteristics of sedimentary rocks in jurassic weakly cemented strata physical and petrographic properties of sedimentary rocks have great influence on their mechanical behavior numerous laboratory tests were conducted on intact sandstones and mudstones obtained from jurassic weakly cemented coal bearing strata several physical and mechanical parameters particularly the rock material constant mi and the brittleness coefficient brit t were determined the microfabric of these sedimentary rocks was also analyzed to quantify their mineral compositions and to determine quantitative relationships among mineral compositions physical and mechanical parameters using the regression analysis overall both bulk density and p wave velocity vp exhibit positive power relationships with uniaxial compressive strength ucs and young s modulus e respectively the ucs of sandstones increases with increasing quartz content and decreasing feldspar content and the brittleness of mudstones increases with the increase of quartz and feldspar contents in addition the rock material constant mi presents a logarithmic correlation with the ratio of feldspar to quartz content for sandstones and a polynomial correlation with the ratio of clay minerals to the quartz and feldspar contents for mudstones

weathering damage evaluation of rock properties in the bunhwangsa temple stone pagoda gyeongju republic of korea the stone pagoda of the bunhwangsa temple in republic of korea was made of piling small brick shaped stones the majority of stone bricks are andesitic rocks with variable geneses rock properties of the pagoda roof suffer partial significant deterioration such as multiple peel offs exfoliation onion peel like decomposition cracks forming round lines and falling off stone pieces the stylobates and tabernacles at the four corners are composed of granitic rocks which are heavily contaminated by lichens and mosses some of these contamination marks show dark black or yellowish brown colors by inorganic secondary hydrates the four tabernacles and northern face of the pagoda body have been exposed to relatively high humidity which causes light gray efflorescence as stalactites between the northern and western sides of the body the efflorescences are composed of calcite gypsum and clay minerals the stone lion statues at the southeast and northeast corners are made of alkali granite while the others are lithic tuff total rock properties of the pagoda consist of 9 708 stone bricks among them 11 0 are fractured 6 7 are fallen off and 7 0 show considerable surface efflorescence which shows that the pagoda has been highly deteriorated by physical chemical and biological weathering the authors strongly suggest long term monitoring and comprehensive conservation researches

seismic anisotropy and shear wave splitting in lower crustal and upper mantle rocks from the ivrea zone experimental and calculated data to quantify the relationships between anisotropy s wave splitting and tectonics we determined the seismic properties of lower crustal and upper mantle rocks outcropping in the ivrea zone northern italy we obtained p and s wave seismic velocities by laboratory direct velocity measurements and or by calculations based on the modal compositions of the rocks the lattice preferred orientations lpos and the single crystal stiffness coefficients measured p and s wave velocities 6 0 7 5 km s 1 and 3 6 4 2 km s 1 are typical of the lower crust the p wave anisotropy is in the range 0 10 shear wave birefringence is in the range 0 0 0 6 km s 1 with typical values between 0 0 and 0 2 km s 1 in many cases the birefringence is clearly related to fabric elements foliation lineation mafic rocks such as anorthosite or pyroxene bearing gabbros exhibit low p wave anisotropies 5 and low shear wave birefringences less than 0 1 km s 1 in contrast the seismic properties of felsic rocks such as biotite bearing gneisses and mafic rocks such as amphibolites display high vp anisotropy 10 and strong birefringence 0 3 km s 1 biotite and amphibole preferred orientations clearly control seismic anisotropy and particularly shear wave splitting in these rocks maximum splitting is observed in directions parallel to the foliation with the fast split shear wave polarized parallel to the foliation plane to have an overview of the seismic properties of this lower crustal section at a broader scale we calculated from our data the anisotropic seismic properties of several hypothetical samples that are perhaps more representative of the regional anisotropy than each sample individually for instance the average lower crustal sample displays an anisotropy of 5 5 for p waves and a birefringence around 0 14 km s 1 for s waves propagating parallel to the foliation we observe little splitting for waves propagating at high angle to the foliation

correlation and correction factor between direct and indirect methods for the ultrasonic measurement of stone samples this study focused on analyzing and calculating the correction factor between direct and indirect methods for the ultrasonic testing of stone monuments using a customized transducer and couplant to achieve this goal the p wave velocity in 11 rock specimens including two artificially weathered samples was measured in a laboratory by applying both direct and indirect methods using an ultrasonic tester statistical interpretation of the results revealed that the indirect p wave velocities were always lower than the direct velocities with the correction factors between them differing by rock type the average correction factors produced by the indirect method were 1 50 in the medium to coarse grained granite sample 1 37 in fine grained granite 1 58 in fine grained diorite 1 38 in medium grained diorite 1 59 in sandstone and 1 71 in marble in addition the regression equation and coefficient of determination r 2 were acceptably high suggesting a sufficient relationship between the two variables for use in engineering this study will significantly contribute to improving the reliability of ultrasonic testing for weathering evaluation of a stone monument

observations of the north polar region of mars from the mars orbiter laser altimeter elevations from the mars orbiter laser altimeter mola have been used to construct a precise topographic map of the martian north polar region the northern ice cap has a maximum elevation of 3 kilometers above its surroundings but lies within a 5 kilometer deep hemispheric depression that is contiguous with the area into which most outflow channels emptied polar cap topography displays evidence of modification by ablation flow and wind and is consistent with a primarily h2o composition correlation of topography with images suggests that the cap was more spatially extensive in the past the cap volume of 1 2 3 10 6 to 1 7 3 10 6 cubic kilometers is about half that of the greenland ice cap clouds observed over the polar cap are likely composed of co 2 that condensed out of the atmosphere during northern hemisphere winter many clouds exhibit dynamical structure likely caused by the interaction of propagating wave fronts with surface topography

boron isotope variations in tourmaline from hydrothermal ore deposits a review of controlling factors and insights for mineralizing systems abstract tourmaline group minerals are typically the predominant host of boron in hydrothermal mineral deposits boron is a fluid mobile element whose isotopic composition reflects many factors that are relevant to understanding mineralizing processes including fluid source s fluid rock interaction and formational temperature a new compilation of 2622 published 11b values for tourmaline from diverse types of hydrothermal ore deposits is presented here with the focus 2215 analyses on seven main types porphyry cu mo au deposits granite related sn w deposits iocg deposits orogenic au deposits stratabound vms and sedex deposits and sediment hosted u deposits the total range of 11b values for the seven types is 26 8 to 35 0 four granite sn w orogenic au stratabound vms and sedex have median 11b values close to the continental crustal average of about 10 the median values for iocg and porphyry cu mo au deposits are higher 3 9 and 2 1 respectively whereas sediment hosted u deposits have distinctly high 11b median 25 3 importantly a considerable range of 11b values exists for tourmaline within each deposit type the smallest 17 8 for granite sn w deposits and the largest 48 0 for iocg deposits the boron isotope variations in tourmaline from different deposits are suggested reflect three levels of controlling factors and how these factors operated is illustrated with selected number of case studies the primary factor is the composition of the boron source secondary effects relate to fluid tourmaline fractionation equilibrium or rayleigh there are commonly also tertiary factors that depend on evolution of the specific deposit these include fluid mixing changing water rock ratio and or depositional temperature influences of other boron bearing minerals and where relevant post ore metamorphism separating the effects of these factors is rarely possible from boron isotopes alone however the growth of multi isotope studies of tourmaline and coexisting phases such as mica as well as developments in modelling experimentation of boron isotopes and element partitioning suggest that this limitation will be overcome

a critical evaluation of the available measurements for the stable isotopes of boron abstract the reported measurements for the stable isotopes of b 11b and 10b in natural materials are compiled critically reviewed and evaluated the selected values along with a discussion of the error indicate the potential exists for using b isotopes in interpreting geochemical environments the isotopic values for 11b range from 31 0 for terrestrial rocks to 40 0 for sea water relative to nbs srm 951 which has a reported 11b 10b ratio of 4 04362 0 00137 2 furtherm the isotope ratios generally form a narrow cluster of values for specific rock types in some instances the reported 11b may be shifted substantially from the mean of unaltered rock as a result of weathering or reaction such as the progressive enrichment of 11b in marine sediments over time due to reaction with sea water an application of widespread interest is the use of b isotopes in environmental studies boron is a contaminant derived from numerous sources such as municipal and industrial waste the 11b in these wastes or processed waters is often significantly different from the 11b of the local ground water which will likely reflect the 11b values of the nearby rocks this modification by contaminated water can be 20 0 different from the 11b of the unaffected water providing a useful tool in delineating the source of contamination and the direction of migration

earliest part of earth s stratigraphic record a reappraisal of the 3 7 ga isua greenland supracrustal sequence investigations of the isua supracrustal rocks in west greenland allow us to identify the protoliths and alteration history for most isua rocks the protoliths consisted of alternating basalt and banded iron formation this sequence was invaded by dunitic sills metamorphosed and later intruded by felsic gneisses pervasive carbonation and k metasomatism produced a sequence of lithologies mimicking those found in modern platform deposits however the protoliths could have originated in a purely oceanic environment with no sialic detrital components the isua sequence probably consists of several tectonic panels some of which are cut by 3810 ma felsic intrusive rocks

improved general circulation models of the martian atmosphere from the surface to above 80 km we describe a set of two new generation general circulation models of the martian atmosphere derived from the models we originally developed in the early 1990s the two new models share the same physical parameterizations but use two complementary numerical methods to solve the atmospheric dynamic equations the vertical resolution near the surface has been refined and the vertical domain has been extended to above 80 km these changes are accompanied by the inclusion of state of the art parameterizations to better simulate the dynamical and physical processes near the surface boundary layer scheme subgrid scale topography parameterization etc and at high altitude gravity wave drag in addition radiative transfer calculations and the representation of polar processes have been significantly improved we present some examples of zonal mean fields from simulations using the model at several seasons one relatively novel aspect previously introduced by wilson 1997 is that around northern winter solstice the strong pole to pole diabatic forcing creates a quasi global angular momentum conserving hadley cell which has no terrestrial equivalent within such a cell the coriolis forces accelerate the winter meridional flow toward the pole and induce a strong warming of the middle polar atmosphere down to 25 km this winter polar warming had been observed but not properly modeled until recently in fact thermal inversions are generally predicted above one and often both poles around 60 70 km however the mars middle atmosphere above 40 km is found to be very model sensitive and thus difficult to simulate accurately in the absence of observations

gravity wave drag in three dimensional atmospheric models of mars gravity waves are disturbances whose restoring force is buoyancy in the atmosphere they are made possible by the variation of potential temperature with height they can be excited by various mechanisms including flow over orography the momentum carried by these disturbances can exert significant drag forces on the mean flow in the terrestrial mesosphere one parameterization of this effect the lindzen gravity wave drag scheme is inserted into two simplified general circulation models gcms of the martian atmosphere and its effects are described the influence of large amplitude planetary scale topography on wave breaking altitudes is discussed we show that above 60 km in altitude gravity wave drag dominates the momentum balance of the martian atmosphere on the largest scales this indirectly alters the thermal state of the atmosphere through the thermal wind relation model winds at this level are consistent with other simpler studies as well as with earth based spectroscopic observations below 60 km the effects of planetary wave mean flow interaction as well as heating associated with hadley circulation descent are significant in determining the wind strength eddy diffusion coefficients derived from the lindzen parameterization above 50 km are consistent with values implied from chemical modeling of the martian middle atmosphere as well as with simpler models of gravity wave drag

geochemistry and boron isotopic compositions of tourmaline from the paleoproterozoic amphibolites ne china implications for the origin of borate deposit abstract the paleoproterozoic metasediments and metavolcanics in the jiao liao ji belt northeastern china host a large number of borate deposits to trace the source of boron in these borate deposits we carried out in situ chemical and boron isotopic studies on tourmalines of amphibolites from the lieryu formation of the liaohe group in the jiao liao ji belt the petrology and the chemical compositions of tourmalines of amphibolites show that these tourmalines formed by influx of b rich fluids during different stages of metamorphism the 11b values of tourmaline continue to decline during the successive metamorphism tourmalines that formed during the prograde metamorphism show higher 11b values 9 52 10 18 than those formed during the peak metamorphism of amphibolite facies 7 22 9 43 subsequently tourmalines with lower 11b values formed during the retrograde metamorphism of greenschist facies which have slightly different boron isotopic compositions in cores 4 18 5 50 and rims 2 66 4 66 mainly due to the temperature effect the boron isotopic variations of tourmalines of amphibolites match well with our modeling study of boron isotope the results suggest that tourmalines may be precipitated from fluids released from dehydration of marine sediments with relative high 11b values 9 during prograde metamorphism in the same way the borate deposits formed from the liberated b rich fluids that interacted with the mg rich carbonates and or silicates

p and s wave anisotropy and shear wave splitting at pressure and temperature in possible mantle rocks and their relation to the rock fabric the seismic properties and their directional dependence have been measured in three potentially mantle derived rocks peridotite ivrea zone italy lherzolitic xenolith massif central france serpentinite the experimental data include the measurement of elastic wave velocities and densities at confining pressures up to 600 mpa and temperatures up to 600 c 600 mpa and the determination of velocity anisotropy and shear wave splitting the petrophysical data can be related to mineral composition and to microstructural characteristics of the rocks macroscopic anisotropy of p and s wave velocities is strongly controlled in the peridodites by the olivine and in the serpentinite by the serpentine antigorite lattice preferred orientation lpo respectively shear wave splitting was found to be an important characteristic of the anisotropic rocks the study shows that for the interpretation of shear wave splitting the direction of wave propagation in relation to the lpos of the major minerals and to the symmetry of their lattice fabric is of great importance in the ivrea peridotite exhibiting rhombic symmetry there is practically no shear wave splitting to be observed for s waves propagating parallel to the olivine 100 axes and the maximum shear wave splitting is not coupled with the direction of highest p wave velocity in the transversely isotropic massif central xenolith shear waves do not split when propagating parallel to the olivine 010 maximum coinciding with the direction of the radial symmetry axis of the olivine fabric the experimental data are principally in accordance with velocity calculations based on the measured olivine lpo and the olivine single crystal stiffness coefficients implications for the interpretation of seismic data are discussed

static and dynamic mechanical properties of sedimentary rock after freeze thaw or thermal shock weathering abstract rocks in engineering works and as building materials are always suffering freeze thaw f t and thermal shock ts weathering and engineering rocks usually involve responses to impact loads from blasting operation mechanized construction and seismic oscillation sedimentary rock distributes extensively and is important for engineering geological and hydrogeological works for a deeper understanding of the f t and ts effects on the rock behaviors physical tests static compressions and dynamic impacts were carried out on red sandstone free from and after artificial f t or ts cycles in this work laboratory tests show the significant physic mechanical deterioration of red sandstone after f t or ts weathering compared to fresh specimens red sandstone after 10 f t or ts cycles performs poorly in both the static compression and shpb impact tests and f t ts induced decreases of ucs and modulus are more remarkable under dynamic impacts than under static loads dynamic mechanical behaviors of both fresh and f t ts weathered red sandstone have distinguishable strain rate effects and water content significantly affects the strain rate effects on mechanical behaviors water and temperature variation play important roles in the rock weathering process in this work water effects during the rock weathering process were summarized as solvent effect and medium effect while temperature variation damaged red sandstone meanly in two ways non uniform thermal deformation of mineral grains and phase transition of water

evaluation of geo mechanical properties of very weak and weak rock materials by using non destructive techniques ultrasonic pulse velocity measurements and reflectance spectroscopy abstract the main purpose of this study is to evaluate the geo mechanical properties of very weak and weak rock materials by using ultrasonic pulse velocity measurements and considering specifically detailed mineralogical compositions for the purpose p wave velocity v p measurements of 66 core samples of the sedimentary rocks including claystones and mudstones collected from firuzkoy area of istanbul turkey were carried out unconfined compressive strength ucs tests were then conducted the axial deformations recorded during the ucs tests were also evaluated and the elastic moduli of the rock materials e i were calculated statistical relations were investigated between the values of p wave velocity measurements and the ucs and e i in order to evaluate the effects of detailed mineralogical compositions on the prediction performances of the empirical equations v p ucs and v p e i the reflectance spectroscopy was introduced 1035 spectral measurements were taken from smooth and fresh surfaces of the failed core samples different genetic rock types were defined according to crystal field effect and charge transfer absorptions of transition elements and water and oh vibrational spectral diagnostics the statistical relations were reinvestigated and the individual empirical equations were reproduced for each genetic rock type the mean values of the multiple coefficients of correlations r were obtained to be 0 904 and 0 916 for the equations of v p ucs and v p e i considering the maximum values of r the increment rates for the values of the explained variances reach up to 14 3 and 13 5 for the equations respectively additionally according to the results of the analysis of variance anova evaluations the empirical equations of v p ucs and v p e i reproduced for each genetic rock type were found to be statistically significant at the significance level of 0 05 as a consequence the non destructive techniques v p measurements and reflectance spectroscopy could be efficiently used together for the evaluation of the geo mechanical properties of very weak and weak rock materials in particular

the first mars thermospheric general circulation model the martian atmosphere from the ground to 240 km 1 the martian general circulation model gcm at the laboratoire de meteorologie dynamique lmd has been extended up to approximately 240 km and it is now the first gcm to fully simulate the martian atmosphere from the ground up to the thermosphere in this paper we summarize the processes that have been added and give a first simple study of the effects of parameterized orographic gravity waves on the zonal mean fields this first study clearly emphasizes the coupling between the different atmospheric regions and notes the importance of having fully coupled models to simulate the atmosphere of mars

alleviation of a systematic westerly bias in general circulation and numerical weather prediction models through an orographic gravity wave drag parametrization systematic westerly biases in the northern hemisphere wintertime flow of the meteorological office 15 layer operational model and 11 layer general circulation model are described evidence that the failure to parametrize subgrid scale orographic gravity wave drag may account for such biases is presented this evidence is taken from aircraft studies surface pressure drag measurements and studies of the zonally averaged momentum budget a parametrization scheme is described in which the surface stress is proportional to the near surface wind speed and static stability and to the variance of subgrid scale orography the stress is absorbed in the vertical by considering the influence of such gravity wave activity on static stability and vertical wind shear a richardson number dependent wave breaking formulation is devised and the vertical stress profile determined by a saturation hypothesis whereby the breaking waves are maintained at marginal stability it is shown that wave breaking preferentially occurs in the boundary layer and in the lower stratosphere results from a simple zonally symmetric model show how the adjustment to thermal wind balance with a wave drag in the stratosphere warms polar regions by adiabatic descent and decelerates the mean westerlies in the troposphere the influence of the parametrization scheme on integrations of the 11 layer model is described and found to be generally beneficial in a discussion of the reasons why this problem has only recently emerged it is suggested that the satisfactory northern hemisphere winter circulations of previous coarser general circulation models were due to a compensation implied by underestimating both the surface drag and the horizontal flux of momentum by explicitly resolved large scale eddies

non destructive testing for the assessment of granite decay in heritage structures compared to quarry stone several types of granite found in two architectural heritage monuments were assessed with two non destructive portable techniques schmidt hammer rebound and ultrasound velocity vp similar assessments were conducted on the rock from which the granite was originally quarried for comparison the results obtained which revealed the existence of a direct correlation constitute a useful indication of decay particularly if the approximate dates of construction are known and conversely if they are not such stone assessments may provide a rough estimate of when the structure was built both of these convenient portable and non destructive techniques may be used as reliable indicators of the degree of stone decay

mesospheric temperature inversion and gravity wave breaking more than 500 nightly mean temperature profiles have been obtained since 1981 by two rayleigh lidars located in south of france 550 km apart in the mesosphere a temperature inversion a feature persisting for several days is frequently observed simultaneously at both sites from a statistical study of the inversion characteristics it is shown that its altitude ranges from 55 72 km in winter to 70 83 km in summer while its probability of occurrence presents a semi annual variation with a maximum higher in winter than in summer and a minimum lower in may than in september the seasonal variation of the temperature inversion is shown to be very similar to that of the mst radar echoes in the mesosphere associated to turbulent layers generated by the breaking of gravity waves a crude estimate of the amplitude growth with height of a gravity wave in the presence of an inversion layer indicates that the wave will break preferably inside and above this layer the persistence of a temperature inversion during several days with amplitude as large as 40 k is tentatively explained by the heating of the turbulent layers generated by the continuous breaking of gravity waves above the secondary minimum of temperature

boron isotope systematics of marine sediments abstract boron contents and boron isotopic compositions were determined for modern and ancient permian to miocene marine sediments including pelagic clay calcareous ooze siliceous ooze and neritic clay sediments 11b values of modern marine sediments range from 6 6 to 4 8 isotopic variation is controlled by the simple mixing of four major constituents detritus of continental origin marine smectite biogenic carbonates and biogenic silica detritus of continental origin with an average 11b value of 13 to 8 is the low 11b end member constituent of marine sediments and its boron is largely controlled by the concentration of illite which originates from wind or fluvial transport marine smectite biogenic carbonate and biogenic silica on the other hand represent the high 11b end members with 11b values of 2 3 to 9 2 8 0 to 26 2 and 2 1 to 4 5 respectively these high 11b values are the result of the equilibrium uptake of boron from seawater spatial variations in boron isotopes in the pacific sediments are essentially due to the distribution of the above four constituents although ancient argillaceous sediments shale and slate have boron contents that are identical with those of modern equivalents boron contents of limestone and chert are distinctly lower than those of modern calcareous and siliceous oozes ancient marine sediments have systematically lower 11b values 17 0 to 5 6 than those of the modern sediments the lower 11b values can be caused by diagenesis which induces 1 preferential removal of high 11b boron in calcium carbonate and silica during recrystallization and 2 boron isotopic exchange in the course of the smectite illite transition the observed boron isotopic compositions of ancient argillaceous sediments are distinctly different from those of fresh and altered morb therefore boron isotope systematics will be useful in identifying components from the descending oceanic slab involved in the formation of island arc magma and in investigating mantle crust recycling through subduction processes

mean and gravity wave structures and variability in the mars upper atmosphere inferred from mars global surveyor and mars odyssey aerobraking densities 1 we have used density measurements obtained during aerobraking ab on mars global surveyor and mars odyssey to examine mean densities and the characteristics and variability of gravity waves gws in the upper atmosphere of mars mean densities exhibit variability with latitude and season and in response to variable forcing and filtering from below these data also reveal significant variability of gws both spatially and temporally in general gw amplitudes increase while apparent horizontal scales remain the same with increasing altitude the dominant spatial scales at the lower ab altitudes are typically 20 200 km and density fluctuations vary from 5 to 50 though even larger values are occasionally observed gw amplitudes also vary significantly with season being generally larger in winter and at middle and high latitudes and apparently reflecting mean source and filtering conditions amplitudes also appear to vary with longitude and time and may provide clues to variability of and interactions with larger scale motions

detrital metamorphic and metasomatic tourmaline in high pressure metasediments from syros greece intra grain boron isotope patterns determined by secondary ion mass spectrometry the boron isotopic composition of zoned tourmaline in two metasediments from the island of syros determined by secondary ion mass spectrometry sims reflects the sedimentary and metamorphic record of the rocks tourmaline from a silicate bearing marble contains small 20 m detrital cores with highly variable 11b values 10 7 to 3 6 pointing to a heterogeneous protolith derived from multiple sources the sedimentary b isotopic record survived the entire metamorphic cycle with peak temperatures of 500 c prograde to peak metamorphic rims are homogeneous and similar among all analysed grains 11b 0 9 the varying 11b values of detrital cores in the siliceous marble demonstrate that in situ b isotope analysis of tourmaline by sims is a potentially powerful tool for provenance studies not only in sediments but also in metasediments a meta tuffitic blueschist bears abundant tourmaline with dravitic cores of detrital or authigenic origin 11b 3 3 and prograde to peak metamorphic overgrowth zones 1 6 fe rich rims formed during influx of b bearing fluids under retrograde conditions show strongly increasing 11b values up to 7 7 towards the margins of the grains the 11b values of metamorphic tourmaline from syros formed in mixed terrigenous marine sediments reflect the b signal blended from these two different sources and was probably not altered by dehydration during subduction

boron isotope geochemistry of metasedimentary rocks and tourmalines in a subduction zone metamorphic suite abstract in order to understand the behavior of boron b and its isotope fractionation during subduction zone metamorphism b contents and isotopic compositions together with major element compositions were determined for metasedimentary rocks and tourmalines from the sambagawa metamorphic belt central shikoku japan no systematic changes in whole rock b content and isotope composition of the metasediments were observed among the different metamorphic grades indicating the lack of a bulk fluid rock b isotope fractionation as a result of devolatilization both modal abundance and grain size of tourmaline increase with increasing metamorphic grade in contrast b contents in muscovite and chlorite decrease with increasing metamorphic grade these observations combined with mass balance calculations of b suggest the formation of tourmaline during progressive metamorphism from metamorphic fluids containing b mainly derived from muscovite and subordinately from chlorite without allowing significant net removal of b from the metasedimentary rocks tourmalines in the higher grade metasedimentary rocks have zonal structure of b isotope and major element composition with decreasing 11 b and increasing mg mg fe from the inner rim core to the outer rim the change of mg mg fe in the tourmalines with increasing grade is paralleled by similar variation in chlorite these observations suggest that the growing tourmalines record the progressive evolution of the b isotopic composition of the metamorphic fluid in the outermost rims preserving the isotope signature of peak metamorphic p t fluid conditions based on the above observations the 11 b of the tourmaline is thought to have been nearly identical to that of the metamorphic fluid resulting in the apparent b isotopic fractionation factor between metamorphic fluid and whole rock 11 b 10 b fluid 11 b 10 b whole rock which decreases from 1 007 0 003 to 1 001 0 003 from chlorite to biotite zone metamorphism such results together with the formation of tourmaline from and sequestering of b in metamorphic fluids may lead to less b isotopic fractionation as a result of subduction zone devolatilization than noted in suites containing less tourmaline this therefore makes it possible to transport b isotopic signatures which ultimately reflect earth s surface materials to the deep mantle perhaps resulting in mantle b isotope anomalies near convergent margins

on the occurrence and boron isotopic composition of tourmaline in ultra high pressure metamorphic rocks abstract the extensive p t stability and the high chemical variability of tourmaline tur together with its common occurrence in metasediments proves its high potential for petrological and isotope geochemical studies on fluid rock interaction in subduction and collision related rocks this paper reviews the occurrence major element chemistry and boron isotopic composition of tur in high and ultrahigh pressure metamorphic uhpm rocks in addition it presents a new discovery of coesite bearing tur schorl from the erzgebirge germany as well as tur dravite related to the retrograde history of coesite and diamond bearing rocks from the erzgebirge and the kokchetav massif kazakhstan the scarce data on worldwide occurrences of u hpm tur reveal a high occupation of the crystallographic x site dominated by na and the possible presence of excess b with little further distinctiveness in its major element composition when compared with tur from medium grade rocks high k 2 o contents in tur are probably not related to uhp growth or equilibration the b isotopic composition of u hpm tur ranges in 11 b from 16 to 1 with many samples in or below the range of continental crust in contrast tur formed during retrograde fluid influx typically shows high 11 b values up to 28 suggesting heavy b fluids infiltrating the exhuming u hpm units coesite inclusions in tur characterized by raman spectroscopy are regarded as the best indicator for its uhp stability supplementary material analytical methods tourmaline compositions and boron isotope values are available at http www geolsoc org uk sup18354

the mars regional atmospheric modeling system model description and selected simulations the mars regional atmospheric modeling system mrams is introduced and selected model results are presented and compared with landed meteorological data when possible mrams is descended from a nonhydrostatic earth mesoscale and cloud scale model that is widely used for forecasting weather and simulating atmospheric systems over complex terrain mesoscale models such as mrams are ideal tools for making use of the high resolution data sets arriving from mars global surveyor experiments simulation of the mars pathfinder mpf landing site at lsd 142 using 1 2 degree mars orbiter laser altimeter mola derived topography and thermal emission spectrometer thermal inertia is shown to be in good agreement with observed near surface temperature pressure and wind direction simulations of topographically induced thermal circulations and mountain induced gravity waves are shown to be consistent with theory and earlier studies that tie large amplitude mountain waves to strong winds capable of producing dust streaks and local dust lifting events a large eddy simulation of the convective boundary layer provides estimates of vertical profiles of heat flux momentum flux turbulent kinetic energy and vertical velocity variance the model results suggest that the martian atmosphere is roughly two to three times more turbulent than the terrestrial atmosphere during the afternoon but fluxes are roughly an order of magnitude smaller due to the lower density dust devillike circulations are also predicted in the large eddy simulation finally a simulation that examines atmosphere surface interactions near big crater is discussed predicted surface wind stress patterns are consistent with aeolian processes inferred through mars orbiter camera imagery of big crater located near the mpf landing site c 2001 academic press

tourmaline in a mesoarchean pelagic hydrothermal system implications for the habitat of early life abstract the rna world hypothesis requires the synthesis of rna to allow the emergence of life on earth hydrothermal systems have been proposed as potential candidates for constructing complex biomolecules however in order to successfully form rna it is necessary to stabilize ribose a rna carbohydrate component borate has been found to stabilize ribose therefore boron rich hydrothermal systems are important environments concerning the origin of life on earth the 3 2 ga dixon island formation of the west pilbara superterrane western australia is a volcano sedimentary sequence the formation represents a mesoarchean pelagic hydrothermal system which formed adjacent to an immature island arc fine grained tourmaline in addition to biogenic carbonaceous matter and spherulitic and tubular bacteriomorphs are found in black chert a boron rich environment was responsible for the formation of these deposits to explore the implications of such a boron enriched environment on microbial activity modes of occurrence and chemical compositions of the tourmaline were examined the tourmaline is schorl or dravite of the alkali tourmaline group and the boron isotope compositions range in 11b from 7 3 to 2 6 the tourmaline occurs in microcrystalline quartz matrix of black chert veins that cross cut a volcanic unit and also in a bedded black chert which overlays the volcanic unit the volcanic unit contains highly altered zones with hydrothermal veins the associated lithologic and stratigraphic features suggest that the black chert veins were the conduits for upward moving hydrothermal fluids which reached the sea floor subsequently the volcanic unit was covered by organic matter rich cherty sediments that in part were fed and or altered by the hydrothermal fluids these results suggest that the origin of boron enrichment to form dixon island tourmaline is not the associated sedimentary mineral assemblage which includes diagenetic clay low grade metamorphic mica and organic matter instead the tourmaline was directly precipitated from hydrothermal fluid enriched in boron furthermore the hydrothermal fluids had already concentrated the boron in the mesoarchean pelagic system prior to the apex of organic matter production and microbial activity our findings support a hypothesis that the boron enriched hydrothermal environment aided the survival and evolution of early life

secular boron isotope variations in the continental crust an ion microprobe study abstract tourmalines of various chemical compositions hosted in magmatic rocks with ages ranging from 3 8 ga to the present were analysed for 11 b by ion microprobe a large range of 11 b values from 2 to 30 1 5 was observed the 11 b values are correlated with the chemical composition of the tourmalines the li rich tourmalines being enriched in 11 b compared to fe and or mg rich tourmalines this may reflect mixing in the continental crust between a marine reservoir characterized by high li contents and 11 b values and a continental reservoir characterized by low li contents and 11 b values no relationship between the age and the 11 b values is observed for the fe or for the mg rich tourmalines in contrast the 11 b values of the li rich tourmalines show a tendency to regularly decrease with increasing age this pattern is consistent with a simple model of constant boron isotopic fractionation between seawater and the continental crust during the progressive extraction of the continents a variation in the mean 11 b value of the continental crust from 20 ga ago to 7 at present is predicted by the model the largest variation occurred during the first 2 5 ga

boron isotopic composition of tourmaline from massive sulfide deposits and tourmalinites boron isotope ratios 11b 10b have been measured on 60 tourmaline separates from over 40 massive sulfide deposits and tourmalinites from a variety of geologic and tectonic settings the coverage of these localities is global 5 continents and includes the giant ore bodies at kidd creek and sullivan canada broken hill australia and ducktown usa overall the tourmalines display a wide range in 11b values from 22 8 to 18 3 possible controls over the boron isotopic composition of the tourmalines include 1 composition of the boron source 2 regional metamorphism 3 water rock ratios 4 seawater entrainment 5 temperature of formation and 6 secular variations in seawater 11b the most significant control appears to be the composition of the boron source particularly the nature of footwall lithologies variations in water rock ratios and seawater entrainment are of secondary importance the boron isotope values seem especially sensitive to the presence of evaporites marine and non marine and carbonates in source rocks to the massive sulfide deposits and tourmalinites

winter clouds over the north martian polar cap the mars orbiter laser altimeter mola experiment carried on the mars global surveyor spacecraft has observed echoes from cloud tops on roughly 2 5 of the total data taken above 70 n over the northern winter martian polar hood from march to june 1998 sloping wavefronts are commonly seen at latitudes above 70 n implying the presence of propagating buoyancy waves since these wavefronts frequently extend from the surface up to 10 km at a time when co2 is known to be condensing on the polar surface it seems likely that the laser scattering particles consist primarily of co2 ice and that the near surface temperature lapse rate is 0 85 k km 1 set by the vapor pressure of dry ice from the observed wavelengths where available we have calculated the corresponding phase velocities some of these waves appear to be correlated with surface discontinuities and may represent lee waves

the structure of the upper atmosphere of mars in situ accelerometer measurements from mars global surveyor the mars global surveyor mgs z axis accelerometer has obtained over 200 vertical structures of thermospheric density temperature and pressure ranging from 110 to 170 kilometers compared to only three previous such vertical structures in november 1997 a regional dust storm in the southern hemisphere triggered an unexpectedly large thermospheric response at mid northern latitudes increasing the altitude of thermospheric pressure surfaces there by as much as 8 kilometers and indicating a strong global thermospheric response to a regional dust storm throughout the mgs mission thermospheric density bulges have been detected on opposite sides of the planet near 90 degreese and 90 degreesw in the vicinity of maximum terrain heights this wave 2 pattern may be caused by topographically forced planetary waves propagating up from the lower atmosphere

a multiannual record of gravity wave activity in mars s lower atmosphere from on planet observations by the mars climate sounder abstract gravity waves in mars s atmosphere strongly affect the general circulation as well as middle atmospheric cloud formation but the climatology and sources of gravity waves in the lower atmosphere remain poorly understood at earth the statistical variance in satellite observations of thermal emission above the instrumental noise floor has been used to enable measurement of gravity wave activity at a global scale here is presented an analysis of variance in calibrated radiance at 15 4 m 635 665 cm 1 from off nadir and nadir observations by the mars climate sounder mcs on board mars reconnaissance orbiter mro a major expansion in the observational data available for validating models of martian gravity wave activity these observations are sensitive to gravity waves at 20 30 km altitude with wavelength properties h 10 100 km z 5 km that make them likely to affect the dynamics of the middle and upper atmosphere we find that 1 strong moderately intermittent gravity wave activity is scattered over the tropical volcanoes and throughout the middle to high latitudes of both hemispheres during fall and winter 2 gravity wave activity noticeably departs from climatology during regional and global dust storms and 3 strong intermittent variance is observed at night in parts of the southern tropics during its fall winter but frequent co 2 ice clouds prevents unambiguous attribution to gw activity the spatial distribution of wave activity is consistent with topographic sources being dominant but contributions from boundary layer convection and other convective processes are possible

thermal structure and dust loading of the martian atmosphere during late southern summer mariner 9 revisited the temperature structure and dust loading of the martian atmosphere are investigated using thermal emission spectra recorded by the mariner 9 infrared interferometer spectrometer iris the analysis is restricted to a subset of the iris data consisting of approximately 2400 spectra in a 12 day period extending from ls 343 to ls 348 corresponding to late southern summer on mars simultaneous retrieval of the vertical distribution of both atmospheric temperature and dust optical depth is accomplished through an iterative procedure which is performed on each spectrum the inclusion of dust opacity in the retrieval algorithm causes the retrieved temperatures to change by more than 20 k in some atmospheric layers the largest column integrated 9 m dust optical depths 0 4 occur over the equatorial regions the highest atmospheric temperatures 260 k are found at low altitudes near the subsolar latitude 6 s while the coldest temperatures 150 k are found at levels near 1 0 mbar over the winter pole a comparison of temperature maps for 1400 lt and 0200 lt indicates diurnal temperature variations as large as 80 k at low altitudes near the subsolar latitude whereas diurnal temperature changes at pressures less than 1 0 mbar are typically about 10 k both dayside and night side temperatures above about 0 1 mbar 40 km are warmer over the winter north polar region than over the equator or the summer south polar region this thermal structure suggests the existence of a net zonally averaged meridional circulation with rising motion at low latitudes poleward flow at altitudes above 40 km and subsidence over the poles because a meridional circulation transports atmospheric constituents as well as heat it has significant implications for the net flux of dust and water into the polar regions

a reconnaissance of the boron isotopic composition of tourmaline abstract a preliminary investigation of the boron isotopic composition of tourmaline from some boron rich associations has been made the results for tourmaline from metasedimentary parageneses n 12 range from 11b 22 to 22 per mil these data mainly fall between the boron isotopic compositions of normal marine sediments with 11b 2 to 5 per mil and seawater with 11b 39 5 per mil tourmaline samples from granitic pegmatites n 6 on the other hand range from 11b 12 to 5 per mil the data provide a rudimentary indication of the range of boron isotopic variation in tourmaline some of the processes leading to this range and some possible geochemical tracer applications

chemical and boron isotope variations in tourmalines from an s type granite and its source rocks the erongo granite and tourmalinites in the damara belt namibia tourmaline is widespread in metapelites and pegmatites from the neoproterozoic damara belt which form the basement and potential source rocks of the cretaceous erongo granite this study traces the b isotope variations in tourmalines from the basement from the erongo granite and from its hydrothermal stage tourmalines from the basement are alkali deficient schorl dravites with b isotope ratios typical for continental crust 11b average 8 4 1 4 n 11 one sample at 13 n 2 virtually all tourmaline in the erongo granite occurs in distinctive tourmaline quartz orbicules this main stage tourmaline is alkali deficient schorl 20 30 x site vacancy fe fe mg 0 8 1 with uniform b isotope compositions 11b 8 7 1 5 n 49 that are indistinguishable from the basement average suggesting that boron was derived from anatexis of the local basement rocks with no significant shift in isotopic composition secondary hydrothermal tourmaline in the granite has a bimodal b isotope distribution with one peak at about 9 like the main stage tourmaline and a second at 2 we propose that the tourmaline rich orbicules formed late in the crystallization history from an immiscible na b fe rich hydrous melt the massive precipitation of orbicular tourmaline nearly exhausted the melt in boron and the shift of 11b to 2 in secondary tourmaline can be explained by rayleigh fractionation after about 90 b depletion in the residual fluid

the sedimentary cycle of the boron isotopes abstract marine sediments contain two isotopically distinct components a non desorbable fraction with 11b between 4 3 and 2 8 per mil n 10 and a desorbable component with 11b between 13 9 and 15 8 per mil n 6 the adsorption coefficient k for the uptake of b from seawater by fluvial suspended material mississippi has an experimentally determined value of 1 54 0 05 the associated isotope fractionation factor is 0 974 0 003 empirical values for k determined from the analysis of marine sediments n 6 were between 3 and 4 the amount of b adsorbed onto fluvial suspended material during estuarine mixing is about 9 109 moles yr based on pore water data adsorption experiments and comparative size fraction analyses suspended sediments from the mississippi river vs bottom deposits from the delta there is no evidence for the incorporation of b into detrital sediments at low temperature however the high b content of bauer deep metalliferous sediments must be due to incorporation of seawater b during formation of authigenic silicates the 11b of these minerals is 2 3 per mil hydrothermally altered sediments from dsdp hole 477 guaymas basin gulf of california have variable b contents from 33 ppm similar to the unaltered detritus to 1 2 ppm in the recrystallized material the latter has 11b as low as 9 0 per mil substantially lower than the unaltered material hydrothermal solutions collected from vents adjacent to the hole have boron contents elevated by about a factor of 4 relative to seawater and 11b between 16 5 and 23 2 per mil the b mobilized from the sediments is isotopically fractionated with the fluids being preferentially enriched in the heavy isotope analysis of an oxisol profile developed over granite in the guyana shield showed that boron is partially mobilized during weathering with an isotopic offset of 2 5 per mil between bedrock and soil the observed enrichment of b in shales relative to igneous rocks does not occur during weathering or during exposure to seawater at low temperature incorporation occurs only during burial diagenesis at temperatures greater than about 60 c however the enrichments cannot be attained during a single cycle of primary weathering and burial but must be cumulative over many cycles

material characteristics and deterioration evaluation for the 13th century korean stone pagoda of magoksa temple this study focused on the quantitative deterioration evaluation for the magoksa temple stone pagoda of the thirteenth century in korea based on the deterioration map by precise observation and ultrasonic velocity measurements the stone pagoda is composed mainly of fine grained quartz diorite with some granodiorite used in the second story and dew bowl and the replacement stone for restoration in the basement is biotite granite the deterioration map and the 2d contour map projecting ultrasonic velocity showed that the most serious deterioration was to the north face of the pagoda which has about 81 2 deterioration rate and a low velocity range compared with the other directions thus it is required to prepare conservation schemes to reduce deterioration and reinforce the structure it is also required to carry out ground exploitation for calculation of load carrying strength and ground strength together with continuous structural monitoring the results will be important for the stable and long term conservation of the pagoda and will further serve to establish scientific conservation systems of stone cultural heritages in the future

estimates of gravity wave drag on mars indication of a possible lower thermospheric wind reversal spectral gravity wave parameterization suitable for planetary thermospheres applied to wind and temperature from mars climate database reveals enormously strong drag incompatible with the wind distribution it points out to a possible wind reversal in the 110 140 km layer similar to the one in the earth s lower thermosphere

damage evaluation and conservation treatment of the tenth century korean rock carved buddha statues this study focuses on the lithological characterization quantitative deterioration assessment and conservation treatment of the tenth century rock carved buddha statues in korea the buddha statues were carved on light gray macrocrystalline biotite granite and features microcline phenocrysts and pegmatite patches the rock forming minerals are quartz plagioclase microcline and biotite showing micrographic and porphyritic textures feldspars and biotite in the host rock have been partly altered into sericite and chlorite by weathering the surface of the buddha statues is remarkably irregular due to granular disintegration and the differential weathering of the quartz and microcline in addition horizontal and vertical cracks in the host rock have promoted mechanical weathering biological colonization of the statues was serious and featured dark gray and yellowish green lichen dark green bryophyte and some plants the buddha statues were evaluated as the highly weathered rock by ultrasonic survey the lower parts under the influence of water and areas with severely broken surfaces showed a much more advanced weathering grade therefore scientific conservation treatment was carried out for the long term maintenance and conservation of the buddha statues after pretests dry wet and chemical cleanings were applied to the statues next joining of cracked parts and surface consolidating were executed finally the site environment was improved by installation of drain and trimming trees around the statues to ensure more stable long term conservation

density variability at scales typical of gravity waves observed in mars thermosphere by the mgs accelerometer 1 examination of the small scale density perturbations in mars thermosphere inferred from mars global surveyor mgs accelerometer data reveals wave like structures consistent with gravity waves the structures are interpreted to be horizontal with dominant wavelengths of 100 300 km observed along the orbital path density perturbations are significantly stronger in winter versus spring summer suggesting that the zonal mean winds play a major role in filtering these waves there is also evidence of possible modulation by the mean winds due to local time differences no correlation is found with the underlying topography a source region on earth for gravity waves in fact density perturbations in the northern hemisphere are observed to be greater than those in the southern hemisphere which has a higher orographic variance over the martian tropics an observed source region for gravity waves density perturbations are again not elevated leaving questions on how gravity waves observed in the lower atmosphere are related to those observed in the thermosphere

impact of gravity waves on the middle atmosphere of mars a non orographic gravity wave parameterization based on global climate modeling and mcs observations the impact of gravity waves gw on diurnal tides and the global circulation in the middle upper atmosphere of mars is investigated using a general circulation model gcm we have implemented a stochastic parameterization of non orographic gw into the laboratoire de meteorologie dynamique lmd mars gcm lmd mgcm following an innovative approach the source is assumed to be located above typical convective cells urn x wiley jgre media jgre21298 jgre21298 math 0001250 pa and the effect of gw on the circulation and predicted thermal structure above 1 pa urn x wiley jgre media jgre21298 jgre21298 math 000250 km is analyzed we focus on the comparison between model simulations and observations by the mars climate sounder mcs on board mars reconnaissance orbiter during martian year 29 mcs data provide the only systematic measurements of the martian mesosphere up to 80 km to date the primary effect of gw is to damp the thermal tides by reducing the diurnal oscillation of the meridional and zonal winds the gw drag reaches magnitudes of the order of 1 m s sol above 10 urn x wiley jgre media jgre21298 jgre21298 math 0003 pa in the northern hemisphere winter solstice and produces major changes in the zonal wind field from tens to hundreds of m s while the impact on the temperature field is relatively moderate 10 20 k it suggests that gw induced alteration of the meridional flow is the main responsible for the simulated temperature variation the results also show that with the gw scheme included the maximum day night temperature difference due to the diurnal tide is around 10 k and the peak of the tide is shifted toward lower altitudes in better agreement with mcs observations

global and seasonal distribution of gravity wave activity in mars lower atmosphere derived from mgs radio occultation data 1 temperature profiles from mars global surveyor mgs radio occultation measurements reveal vertical wave structures assumed to be atmospheric gravity waves in mars lower atmosphere for each vertical temperature profile derived from a radio occultation measurement wave energy density is calculated and results are locally averaged to derive a global distribution of gravity wave activity global distributions are determined for all values of solar longitude and for solar longitudes corresponding to northern summer and winter to show seasonality and for vertical wavelengths less than 10 km to remove the contribution from thermal tides which dominate in the martian tropics at larger vertical wavelengths the global energy density patterns show significant wave activity over the tropics and the mountainous tharsis region averaged over all seasons and enhanced activity in northern summer compared to winter for the most part the observed data does not correlate well with the orographic forcing schemes used to model gravity waves in general circulation models for mars suggesting that wave sources other than orography play an important role on mars

field characterisation of weathered ankara andesites abstract this paper presents field and some index properties of weathered ankara andesites carried out over a period of 4 years ankara andesites are distributed widely around the city of ankara on which numerous important structures have been founded thus the weathering characteristics of ankara andesites both from the engineering geological and the rock mechanics points of view are important the field work involved assessment of the rock mass weathering grades conduction of simple field tests schmidt hammer and point load tests on the rock materials characterisation of discontinuities and collection of representative samples from each weathering grade for laboratory testing the relationship between the experimentally determined parameters and quantitative engineering geological descriptions provided a simple geological method for the assessment of the design parameters and mapping the distribution of mass weathering grades as a result of the evaluation an idealized weathering profile and the scale of rock mass weathering grades together with their range of thicknesses were proposed some index tests such as effective porosity schmidt hammer value shv point load strength and seismic velocity provided good relations with the degree of weathering

boron isotopic composition of tourmalines from the 3 8 ga old isua supracrustals west greenland implications on the δ11b value of early archean seawater abstract the boron isotope composition of different occurrences of tourmalines in the 3 8 ga old isua west greenland supracrustals has been analysed by ion microprobe tourmalines in the mafic volcaniclastics have 11 b values between 12 6 and 5 8 with a mean at 3 2 5 1 these values are close to the values previously reported for tourmalines in the isua acid volcanic tuffs 6 7 1 4 and indicate no difference in 11 b value of the mantle or the continental crust between the present day and early archean times in contrast tourmalines in a marine conglomerate have low and homogeneous 11 b values of 20 2 2 2 for these tourmalines which are of authigenic origin having formed through metamorphism of pre existing marine clays a 11 b of 8 7 can be calculated for the unmetamorphosed marine sediments deposited before 3 8 ga at isua a value of 27 11 is calculated for the 11 b value of seawater at 3 8 ga the large error arises because the 11 b value of marine sediments are controlled by 1 the ratio of detrital to chemically precipitated boron and 2 the boron isotope fractionation between precipitated boron and dissolved boron in seawater a high 11 b similar to the present day value of 40 seems rather unlikely unless the fraction of detrital b in marine sediments was as high as today a lower value of 27 11 for early archean seawater is consistent with mass balance of boron between seawater mantle and continental crust

solstitial temperature inversions in the martian middle atmosphere observational clues and 2 d modeling abstract the possible existence of stable warming at middle altitudes in the martian atmosphere was first examined by j r barnes j geophys res 95 1401 1990 in one dimensional modeling of the effect of breaking gravity waves on the general circulation this work was motivated by infrared observations of d deming m j mumma f espenak t kostius and d zipoy icarus 66 366 1986 which suggested temperatures far from radiative equilibrium above polar regions at solstice new observational evidence was obtained from heterodyne measurements of the j 2 1 12 co and 13 co transitions made during the 1988 opposition at this date corresponding to southern summer solstice these lines were mapped as a function of the position on the martian disk with the iram 30 m telescope wind velocities near 50 km altitude and vertical thermal profiles were derived from the doppler shift and the line profiles respectively at various locations on mars the northern winter hemisphere profiles indicate the presence of a warm layer in the 40 60 km altitude range with a relative warming of 5 k compared to smoothly decreasing temperature profiles such as those found in the southern hemisphere this may be interpreted in terms of a temperature inversion in the northern middle atmosphere such a phenomenon may be similar to the stable inversion layers observed in the terrestrial mesosphere which are believed to be a response to the gravity wave activity we show that a zonally averaged model of the martian middle atmosphere using the parametrization of gravity waves effects propounded by r s lindzen j geophys res 86 9707 1981 is able to produce both a plausible zonal wind field consistent with the measurements of e lellouch j j goldstein s w bougher g paubert and j rosenqvist astrophys j 383 401 1991 and a thermal field in good agreement with the observations the 2 d modeling further indicates that weak equatorial thermal inversions may occur due to the penetration of the summer hemisphere retrograde jet into the winter hemisphere

initial results from radio occultation measurements with mars global surveyor a series of radio occultation experiments conducted with mars global surveyor in early 1998 has yielded 88 vertical profiles of the neutral atmosphere the measurements cover latitudes of 29 n to 64 s and local times from 0600 through midnight to 1800 during early summer in the southern hemisphere ls 264 308 retrieved profiles of pressure and temperature versus radius and geopotential extend from the surface to the 10 pa pressure level near surface uncertainties in temperature and pressure are about 1 k and 2 pa respectively far smaller than in previous radio occultation measurements at mars the profiles resolve the radiative convective boundary layer adjacent to the surface and also reveal gravity waves particularly at northern and equatorial latitudes which appear to be breaking in some cases distinctive meridional gradients of pressure and temperature indicate the presence of a low altitude westerly jet at latitudes of 15 30 s at southern summer solstice this jet appears in predictions of general circulation models in connection with the strong seasonal cross equatorial hadley circulation the pressure gradient at 2 km altitude implies a wind speed of 33 m s 1 stronger than predicted which may help explain the occurrence of numerous local dust storms within this latitude band in late southern spring these measurements also characterize the response of the atmosphere to stationary thermal forcing at midsouthern latitudes where high terrain south of tharsis and low terrain in hellas planitia produce large zonal temperature variations in the lowest scale height above the surface pressure measured at constant geopotential decreases at an average rate of 0 13 per degree ls due primarily to condensation of co2 at the north pole

velocity anisotropy in granodiorite and quartzite due to the distribution of microcracks summary the spatial anisotropy of p wave velocities was investigated in spherical samples of granodiorite and quartzite and correlated with the orientation of microcracks and grain boundaries determined optically by universal stage techniques the preferred orientation of normals to cleavage cracks of biotite and amphibole in granodiorite correlates well with the direction of maximum velocity increase under hydrostatic pressure although the minerals form only nine per cent of the volume irregular microcracks in an almost monomineral quartzite have only a very small effect on the velocity anisotropy although they are also preferentially oriented the nature of the microdiscontinuities is of primary importance for the velocity anisotropy observed at atmospheric and low hydrostatic pressures