working models for spatial distribution and level of mars seismicity 1 we present synthetic catalogs of mars quakes intended to be used for performance assessments of future seismic networks on the planet we have compiled a new inventory of compressional and extensional tectonic faults for the planet mars comprising 8500 faults with a total length of 680 000 km the faults were mapped on the basis of mars orbiting laser altimeter mola shaded relief hence we expect to have assembled a homogeneous data set not biased by illumination and viewing conditions of image data updated models of martian crater statistics and geological maps were used to assign new maximum ages to all faults on the basis of the fault catalog spatial distributions of seismicity were simulated using assumptions on the available annual seismic moment budget the moment frequency relationship and a relation between rupture length and released moment we have constructed five different models of martian seismicity predicting an annual moment release between 3 42 1016 nm and 4 78 1018 nm and up to 572 events with magnitudes greater than 4 per year as upper limit end member case most events are expected on the tharsis shield but minor seismic centers are expected south of hellas and north of utopia planitia

thrust faulting and hydrocarbon generation reply this paper is a rebuttal of an earlier paper trying to refute the claims of these authors they believe this reply illustrates that the simplifications used by warner and royse 1987 in their model are generally inappropriate to describe the thermal history of units in the western overthrust belt as well as other overthrust regions although their shortcuts produce results that are generally consistent with measured maturity values for some specific modeling sites the differences in maturation history and the mismatch for the general thrust case make their model a less effective predictive tool at this stage in the understanding of overthrust thermal processes you cannot predict a priori when the thermal effects of thrusting will be significant and when they will be minimal defining the exact relationship between thrusting and hydrocarbon accumulations in overthrust areas requires additional work and data collection in particular workers must consider case histories where the hanging wall contains thick sequences of resistant strata by incorporating additional constraints instead of returning to the simplified assumption of constant thermal gradients in tectonic regions the understanding of the evolution and maturation history of thrust belts is improved

mars interior structure and excitation of free oscillations based on available chemical models of the planet philos trans r soc london 349 1994 285 supply and loss of volatile constituents during the accretion of terrestrial planets in s k attreya j b pollack m s matthews eds origin and evolution of planetary and satellite atmospheres univ arizona press pp 268 288 icarus 126 1997 373 phys earth planet inter 112 1999 43 space sci rev 92 2000 34 a new set of global models of the martian interior has been constructed a model comprises four submodels a model of the outer porous layer a model of the crust a model of the mantle and a model of the core the first 10 11 km layer is considered as an averaged transition from regolith to consolidated rock the mineral composition of the crustal basaltic rock varies with depth because of the gabbro eclogite phase transition as a starting point for mantle modeling the experimental data obtained by bertka and fei j geophys res 102 1997 525 earth planet sci lett 157 1998 79 along the areotherm have been used iron content of the mantle being varied the measured or estimated up to now elastic properties for a set of mantle minerals are used seismic velocities determined from new high p t data on elastic properties are 2 3 lower than the velocities calculated earlier new high p t measurements of the density of fe fe fes and feh enable us to refine the core model taking into account available chemical models and the fact that noticeable amount of hydrogen could enter the martian core during its formation solar syst res 30 1996 456 such parameters as a ferric number of the mantle fe sulfur and hydrogen content in the core are varied the following tendency is seen the presence of hydrogen leads to the increase of the fe si ratio and decreases fe in the mantle due to the increase of the core radius the higher sulfur and hydrogen content in the core and the smaller mantle fe the less likely a perovskite layer exists the modeling shows that to obtain the fe si ratio up to the chondrite ratio of 1 71 more than 50 mol of hydrogen should be incorporated into the core in the second part of the paper based on the available estimates of the martian seismic activity and the sensitivity of current instruments the amplitudes for different types of free oscillations have been estimated it is found down to what depth the normal modes can sound the planetary interiors a marsquake with a seismic moment of 10 25 dyn cm is required for spheroidal oscillations with 17 to be detected these spheroidal modes are capable sounding the outer layers of mars down to a depth of 700 800 km

possible long term decline in impact rates 1 martian geological data abstract quantin et al quantin c allemand p mangold n delacourt c 2004a icarus 172 555 572 tabulated crater count data for 56 landslides along the walls of valles marineris under the assumption of a constant cratering rate after about 3 gyr ago as used in the 1999 2005 iterations of the crater chronology isochron system of hartmann and in the hartmann and neukum system these data indicate a regularly increasing rate of landslides which would be difficult to explain we suggest that these data may support a decline in inner solar system cratering rates by about a factor of 3 since 3 gyr ago not unlike predictions based on asteroid belt collision models such a decline is also supported by our review of data on lunar impact melts and glass spherules in a companion paper hartmann w k quantin c mangold n 2007 icarus 186 11 23 such models produce not only a more uniform rate of landslides over the last 3 gyr but also a more uniform rate of resurfacing processes which also had an apparent increase under the assumption of a constant cratering rate

seismicity on tidally active solid surface worlds tidal interactions between planets or stars and the bodies that orbit them dissipate energy in their interiors the dissipated energy heats the interior and a fraction of that energy will be released as seismic energy here we formalize a model to describe the tidally driven seismic activity on planetary bodies based on tidal dissipation to constrain the parameters of our model we use the seismic activity of the moon driven by tidal dissipation from the earth moon interactions we then apply this model to predict the amount of seismic energy release and largest seismic events on other moons in our solar system and exoplanetary bodies we find that many moons in the solar system should be more seismically active than the earth s moon and many exoplanets should exhibit more seismic activity than the earth finally we examine how temporal spatial variations in tidal dissipation manifest as variations in the locations and timing of seismic events on these bodies

on deck seismology lessons from insight for future planetary seismology before deploying to the surface of mars the short period sp seismometer of the insight mission operated on deck for a total of 48 hr this data set can be used to understand how deck mounted seismometers can be used in future landed missions to mars europa and other planetary bodies while operating on deck the sp seismometer showed signals comparable to the viking 2 seismometer near 3 hz where the sensitivity of the viking instrument peaked wind sensitivity showed similar patterns to the viking instrument although amplitudes on insight were 80 larger for a given wind velocity however during the low wind evening hours the instrument noise levels at frequencies between 0 1 and 1 hz were comparable to quiet stations on earth although deployment to the surface below the wind and thermal shield lowered installation noise by roughly 40 db in acceleration power with the observed noise levels and estimated seismicity rates for mars detection probability for quakes for a deck mounted instrument is low enough that up to years of on deck recordings may be necessary to observe an event because the noise is dominated by wind acting on the lander though deck mounted seismometers may be more practical for deployment on airless bodies and it is important to evaluate the seismicity of the target body and the specific design of the lander detection probabilities for operation on europa reach over 99 for some proposed seismicity models for a similar duration of operation if noise levels are comparable to low wind time periods on mars

two dimensional modeling of the p t t paths of regional metamorphism in simple overthrust terrains quantitative modeling of metamorphic p t t paths in thrust belts has so far been limited to one dimensional simplification we have developed a two dimensional time dependent finite element procedure capable of tracing and updating fault and strata boundaries during faulting for modeling thermal evolution of overthrust terrains we show that the two dimensionality of an overthrust and the speed and duration of thrusting have significant effects on the p t t paths of rocks in orogenic belts the results suggest that petrological studies of p t paths of rocks from different lateral positions in an orogenic belt along with two dimensional modeling procedure can put strong constraints on models of regional tectonic processes

an integrated thermal and isotopic study of the diagenesis of the brent group alwyn south u k north sea abstract the petrography fluid inclusion thermometry and isotope geochemistry of diagenetic cements are used to reconstruct the pore fluid history of the middle jurassic brent group reservoir sandstones in the alwyn south area of the u k north sea the study focuses on a relatively limited area of three adjacent reservoir compartments at successively higher structural levels the cement assemblage of kaolinite quartz and illite has resulted in severe deterioration of otherwise good reservoir quality early precipitation of vermiform and late blocky kaolinite was succeeded by a period of relatively intense illite precipitation temperature estimates for kaolinite precipitation of 80 c and 18o of 15 3 suggest co existing fluids of 18o 3 quartz cementation overlapped both kaolinite and illite formation fluid inclusion data indicate that quartz cementation took place at temperatures of 109 7 c pore fluid salinities were 4 wt nacl with a h2o o isotopic composition of 1 o 0 5 smow the fluids which precipitated coexisting illite were compositionally homogeneous with equilibrium 18o water compositions of 0 5 smow illite sd values range from 33 to 50 smow these fluid inclusion and isotopic data suggest that both quartz and illite were precipitated from pore waters with a uniform marine signature this is consistent with the predominantly marine to paralic depositional context of the brent group in alywn south illite precipitation was followed by hydrocarbon emplacement between the middle eocene and lower oligocene

burial history and kinetic modeling for hydrocarbon generation part i the galo model this paper discusses the principles and applications of the galo computer program which generates numerical simulations of the evolution of a sedimentary basin the program calculates variations in the sedimentary bed thickness predicts the thermal regime in the sedimentary cover or in the basement and estimates the potential hydrocarbon yield of the source rocks alternative methods for determining the magnitude of tectonic subsidence of the basement surface within the framework of a local isostasy model are applied to provide a detailed model of the sequential tectonic thermal events involved in the development of the basin the program determines reaction parameters controlling the maturation of the organic matter in source rocks these parameters are based largely on the hydrocarbon pyrolysis yield data and the stage of maturation of the organic matter entered into the program neglecting this stage drastically displaces the reaction spectrum toward higher energies leading to considerable underestimation of hydrocarbon output

thrust faulting and hydrocarbon generation discussion following the discovery of large volumes of hydrocarbons in the cordilleran thrust belt of southwestern wyoming and northern utah angevine and turcotte 1983 edman and surdam 1984 and furlong and edman 1984 discussed the role of thrust faulting in hydrocarbon generation the authors concluded that overthrusting plays an important or even dominant role in the process of hydrocarbon generation in overthrust terrains these conclusions may be in error because they are based on a mathematical analysis of thermal and geologic models that have little resemblance to actual thrust belt geology in this discussion the authors discuss shortcomings of the thermal model used in the papers referred to above emphasize the differences between their model and the geologic facts as they exist in thrust belts in general and in western wyoming in particular and caution readers about applying the conclusions based on such a model in the search for hydrocarbons they contend that the temperature effects of thrust faulting were rather insignificant in the process of hydrocarbon generation in the wyoming thrust belt

estimates of seismic activity in the cerberus fossae region of mars 1 the 2016 nasa insight lander is the first planetary mission designed to study the deep interior of mars insight s seismic experiment for interior structure seis package will quantify global and regional seismic activity and determine parameters like core properties mantle composition and martian lithospheric thickness an improved understanding of the location magnitude and frequency of potential seismic sources is essential for optimization of instrument design sampling strategy and interpretation of mission data we focus on forecasting seismic activity for the cerberus fossae of the elysium planitia chosen for their proximity to the proposed landing site and their recent formation and assuming these are active tectonic grabens the minimum age we determine for the units around the fossae using context camera and high resolution imaging science experiment imagery for crater density surveying is 10 ma placing them in the late amazonian we are able to determine the rate of motion from measurements of observed throw assuming that the faults remain active digital terrain models made from stereo image pairs from the high resolution stereo camera hrsc are used to determine the maximum throw on four graben systems using these measured throws to estimate a length averaged slip and assuming an inferred slip rate from surface age we estimate an annual moment release of 1 58 1 03 2 35 1017nm from this we calculate an annual size frequency distribution of events using the gutenberg richter relationship we estimate that between 1 5 100and 1 9 105events per year will have an amplitude greater than the peak band noise and so will be detectable at the insight landing site

thermal effects of thrust faulting abstract calculations based on simple models of overthrust sheets in crystalline basement rocks show that significant thermal effects may result from their movements if rates are sufficiently high e g plate tectonic rates the thrust sheets sufficiently thick 5 10 and 15 km are modelled here the distances moved sufficiently large and for reasonable values of the coefficient of friction along the thrust plane overthrusting can cause metamorphic mineral zonations and heat flow anomalies observable in the field regions where large scale overthrusting has occurred should be characterized by a decrease with depth of grade of metamorphic mineral assemblages and anomalously low heat flow the theoretical effects are presented as a series of maximum temperature vs depth and heat flow vs time plots

expected seismicity and the seismic noise environment of europa seismic data will be a vital geophysical constraint on internal structure of europa if we land instruments on the surface quantifying expected seismic activity on europa both in terms of large recognizable signals and ambient background noise is important for understanding dynamics of the moon as well as interpretation of potential future data seismic energy sources will likely include cracking in the ice shell and turbulent motion in the oceans we define a range of models of seismic activity in europa s ice shell by assuming each model follows a gutenberg richter relationship with varying parameters a range of cumulative seismic moment release between 10 16 and 10 18 nm yr is defined by scaling tidal dissipation energy to tectonic events on the earth s moon random catalogs are generated and used to create synthetic continuous noise records through numerical wave propagation in thermodynamically self consistent models of the interior structure of europa spectral characteristics of the noise are calculated by determining probabilistic power spectral densities of the synthetic records while the range of seismicity models predicts noise levels that vary by 80 db we show that most noise estimates are below the self noise floor of high frequency geophones but may be recorded by more sensitive instruments the largest expected signals exceed background noise by 50 db noise records may allow for constraints on interior structure through autocorrelation models of seismic noise generated by pressure variations at the base of the ice shell due to turbulent motions in the subsurface ocean may also generate observable seismic noise

intraplate earthquakes and the state of stress in oceanic lithosphere abstract the sources of stress responsible for oceanic intraplate earthquakes and their usefulness for inferring the tectonic stress field are investigated through a synthesis of the source mechanisms of 58 of the largest such events determined by inversion of long period p and sh waveforms further constraints are provided by the global distribution of oceanic intraplate seismicity and a calculation of the seismic moment release per unit volume of seismogenic lithosphere as a function of lithosphere age although frequently associated with relict tectonic features large oceanic intraplate earthquakes are generally reliable indicators of the state of stress in the source region most oceanic intraplate seismicity occurs in young lithosphere

physical properties of cenozoic mudstones from the northern north sea impact of clay mineralogy on compaction trends vertical and lateral changes in physical properties in cenozoic mudstones from the northern north sea basin reflect differences in the primary mineralogical composition and burial history which provides information about sedimentary facies and provenance integration of well log data with mineralogical information shows the effect of varying clay mineralogy on compaction curves in mudstones the main controlling factor for the compaction of eocene to early miocene mudstones within the north sea is the smectite content which is derived from volcanic sources located northwest of the north sea mudstones with high smectite content are characterized by low p wave velocities and bulk densities compared to mudstones with other clay mineral assemblages at the same burial depths smectitic clays are important during mechanical compaction because they are less compressible than other types of clay minerals a comparison between well log data and experimental work also shows that smectite may be a controlling factor for overpressure generation in the smectite rich eocene and oligocene sediments at greater burial depths and temperatures 70 80c the dissolution of smectite and precipitation of illite and quartz significantly increases velocities and densities miocene and younger mudstones from the northern north sea have generally low smectite contents and as a result have higher velocities and densities than eocene and oligocene mudstones lateral differences in the compaction trends between the north and south for these sediments also exist which may be related to two different source areas in the pliocene the log derived petrophysical data from the northern north sea basin show that mudstone lithologies have very different compaction trends depending on the primary composition simplified compaction curves may therefore affect the outcomes from basin modeling the amplitude versus offset response of hydrocarbon sands and the seismic signature on seismic sections are also dependent on the petrophysical properties of mudstones and will vary depending on the mineralogical composition

seismic response of the mars curiosity rover implications for future planetary seismology abstract seismic measurements are an important tool for exploration of planetary interiors but may not be included in missions due to perceived complexity in placement of sensitive instruments on the surface to help address this concern we assess the fidelity of recordings of ground motion by an instrument placed on the deck of the engineering model of the mars science laboratory compared with an identical instrument placed on the ground directly beneath comparison of the recordings reveals clear recordings of teleseismic earthquakes on both instruments the transfer function between the instruments demonstrates the deck instrument is affected by resonance frequencies of the lander and does not faithfully record ground motion at these frequencies or higher in addition additional decoherence is observed near 1 hz during periods of strong airflow due to air conditioning cycling however excellent coherence and a transfer function near 1 can be observed in the important seismic band between 2 and 30 s at all times and extending up to the lander resonances during the night time when air conditioning was not running this suggests a deck mounted seismic instrument may be able to provide valuable science return without requiring additional deployment complexity

time and temperature in petroleum formation application of lopatin s method to petroleum exploration n v lopatin in the soviet union has developed a method for taking both time and temperature into account as factors in thermal maturation of kerogen lopatin s time temperature index of maturity tti values correlate with the thermal regimes corresponding to generation and preservation of hydrocarbons because such information is potentially of great interest for oil exploration a calibration and evaluation have been made of lopatin s method within the limitations of the data presently available the following statements can be made 1 the rate of the chemical reactions involved in thermal maturation of organic material appears to double with every 10 c 18 f rise in temperature 2 threshold values of lopatin s time temperature index of maturity tti are 15 onset of oil generation 75 peak oil generation 160 end oil generation 500 40 oil preservation deadline 1 000 50 oil preservation deadline 1 500 wet gas preservation deadline 65 000 dry gas preservation deadline 3 tti values calculated from lopatin reconstructions consistently agree with other maturation parameters commonly used by petroleum geochemists potential applications of lopatin s method for oil exploration include timing of oil generation calculation of volume of hydrocarbons generated within a basin and determination of economic deadlines

graphic approach to determination of hydrocarbon maturation in overthrust terrains with the current exploration efforts in areas of overthrust tectonics it is important to evaluate efficiently and effectively the effects of thrust related thermal perturbations on hydrocarbon maturation a simple graphic technique which combines lopatin diagrams with theoretical models of temperatures in overthrust regimes allows one to develop relatively detailed models for the timing of hydrocarbon maturation in overthrust terrains these models provide the critical combination between rigorous consideration of thermal perturbations and simplification necessary for routine application the approach described here is applicable not only in cases of simple overthrusting at the surface but can also be modified to include the effects of multiple thrusting events she ts thrust in the subsurface and post thrusting erosion all of these models provide critical constraints on the timing of maturation and migration as well as information on the maturity of potential source rocks

graben and extension in northern tharsis mars a morphometric analysis of north south trending graben at 35 n in northern tharsis is used to provide the first quantitative measurements of crustal extension in and strain for areas of the martian crust that have undergone both extreme and mild deformation these estimates also demonstrate the viability of the viking data for making such quantitative assessment graben in the region accommodate 8 km of post early amazonian east west extension this extension corresponds to a net regional strain of 0 45 0 61 local strains vary from 1 to 5 extension is nonuniform and localized near 110 south of alba patera and north of ceraunius fossae because of reactivation of preexisting fractures in underlying basement and possibly due to superposition of stress fields from tharsis and alba patera a major mechanical discontinuity in the shallow crust probably representing the base of or a strength contrast within the megaregolith is observed it occurs at a depth of 2 km on the profile flanks and is depressed to about 7 5 km near 110 due to loading of the crust by the volcano a number of more shallow discontinuities occur within the construct and probably represent lithologic contacts

discontinuities in the shallow martian crust at lunae syria and sinai plana detailed photoclinometric profiles across 125 erosional features and 141 grabens in the western equatorial region of mars indicate the presence of three discontinuities within the shallow crust pits troughs and wall valleys tributary canyons within noctis labyrinthus and valles marineris and escarpments within the fretted terrain of sacra fossae and kasei valles show distinct erosional base levels at depths of 0 3 0 6 km 1 km and 2 3 km the shallowest discontinuity corresponds to thickness estimates for the ridged plains unit in this region and thus the discontinuity probably is the contact between a sequence of layered rock making up this unit and the underlying megaregolith the 1 km discontinuity is reflected in the base levels of erosion of all the features studied and it may correspond to the base of the proposed layer of ground ice model calculations using photoclinometric profiles of simple grabens corrected for the effects of mass wasting and the 60 dip of bounding faults measured from the exposed traces of faults on trough walls show that graben bounding faults consistently intersect at the mechanical discontinuity at about 1 km depth this discontinuity may represent an interface between ice laden and dry regolith ice laden and water laden regolith or pristine and cemented regolith a correlation between wall valley head depth and local thickness of the faulted layer suggests that the 1 km discontinuity also controlled the depth of the heads of sapping canyons there is no apparent relation between the pit and trough depths and the local thickness of the faulted layer which can be explained if pits and troughs developed by subsidence into underlying tension cracks that disrupted the 1 km discontinuity the data do suggest however that erosion of shallow pits and troughs was influenced by the 1 km discontinuity the third discontinuity at a depth of 2 3 km corresponds to the proposed base of the martian megaregolith and is probably the interface between overlying ejected breccia and in situ fractured basement rocks

paleoreconstruction by biological markers abstract during diagenesis and conversion of the original lipid fraction of biological systems to petroleum hydrocarbons the following four basic events needed for paleoreconstruction can be monitored by biological markets 1 sourcing 2 maturation 3 migration and 4 biodegradation actual cases of applying biological markers to petroleum exploration problems in different parts of the world are demonstrated cretaceous and phosphoria sourced oils in the wyoming thrust belt can clearly be distinguished from one another by high quality source fingerprinting of biomarker terpanes using gas chromatography mass spectrometry identification of recently discovered biological markers head to head isoprenoids allows subtle source differentiation between oils from sumatra the degree of crude oil maturation in basins from california alaska russia wyoming and louisiana can be assessed by specific novel biomarker ratios 20s 20r sterane epimers field evidence from such interpretation is confirmed by laboratory pyrolysis of the rock an example of immature sumatra rock is given extensive migration is documented by biomarkers in several oils the effect of biodegradation on biomarker steranes and terpanes is exemlified in a california basin all biological marker results are consistent with the geological setting and add a new dimension in assisting the petroleum explorationist toward paleo reconstruction

petroleum generation in the carboniferous strata of the lublin trough poland an integrated geochemical and numerical modelling approach abstract in the lublin trough eastern poland we analysed carboniferous claystone and mudstone rocks by rock eval bitumen composition n alkanes and methylphenathrenes composition and carbon isotopic composition to assess their potential for the generation of hydrocarbons in the lublin trough oil and gas prone type ii iii and iii kerogens occur in upper visean strata average tocav 1 8 wt whereas mainly gas prone type iii kerogen occurs in namurian tocav 1 98 wt and westphalian tocav 1 4 wt strata the carboniferous sequence displays maturity values of 0 5 1 2 ro rock eval tmax 430 460 c palaeo geothermal gradients in the past were much higher than now and locally reached values over 40 c km during the maximum burial event generated hydrocarbons probably consisted of natural gas with limited amounts of oil over most of the area hydrocarbon generation commenced in the late carboniferous mainly 25 but up to maximum 60 transformation ratio and was substantially complete by the time of the asturian inversion in the nw part of the lublin trough petroleum generation continued until the end of the cretaceous with transformation ratios never exceeding 11 at the base of the upper carboniferous mainly gas prone kerogen types and inadequate maturity suggests the discovered petroleum accumulations are derived from devonian and or lower paleozoic strata rather than carboniferous units however the quantitative significance of these source rocks needs further geochemical research

crosscutting relations and relative ages of ridges and faults in the tharsis region of mars abstract observations of ridge fault crosscutting relationships on the ridged plains units surrounding the tharsis region of mars have led to the development of a classification scheme involving three distinct types of intersections ridges crosscut by faults are designated type c and account for 81 of the observed intersections ridges terminated at one end by a fault type t as well as those superposed on grabens type s are less numerous interpretation of the morphology of these intersections and the angles of intersection between ridges and faults with radial trends to major topographic features in the tharsis region have led to the following conclusions 1 the major ridge forming events in the tharsis region were roughly coincident with and in some cases possibly prior to the extensional events that produced the faulting of the tempe and mareotis regions the coprates and memnonia regions and the rifting of valles marinrris 2 the compressional events that formed most of the ridges are restricted in time both by the irrelationship to regional extensional events and by the age of the units on which they formed the suggestion that compressional ridges are a result of a single long term viscoelastic response of the lithosphere to loading of the crust is not supported by this study a model involving one or more isostatically compensated uplifts and subsequent relaxation of the crust after the emplacement of the ridged plains volcanic units is favored

a complete three dimensional failure envelope for shallow footings on sand this paper considers the possibility of constructing a three dimensional failure envelope for a shallow sand supported footing earlier two dimensional work is outlined and data taken from a number of sources to produce best fit eliptical cross sections equations are then presented for a complete three dimensional failure envelope comprising a system of inclined elipses and intersecting parabolas the equations are normalised and compared with test data it is suggested that the three dimensional surface will provide a simpler method for predicting failure loads and the effect of specific combinations

seismological implications of a lithospheric low seismic velocity zone in mars most seismological models for the interior of mars lack an upper mantle low velocity zone however there is expected to be a large thermal gradient across the stagnant conductive lid lithosphere of mars this gradient should tend to decrease elastic wave velocities with increasing depth with this effect dominating the opposing tendency caused by increasing pressure with depth because mars has low gravity an upper mantle lithosphere with a low velocity zone lvz beneath a thin high velocity seismic lid is thus predicted the upcoming nasa insight mission includes a three component seismometer which should provide the first opportunity to directly detect any lithospheric lvz in mars seismic wavefields expected for mars mantle velocity structures with or without a strong lvz are very distinct the lvz models predict shadow zones for high frequency seismic body wave phases such as p s pp and ss etc the most diagnostic waves that can be used to evaluate presence of a lithospheric lvz given a single seismometer are intermediate period global surface waves which travel along the great circle from a seismic source to the seismometer an lvz produces distinctive dispersion with a rayleigh wave airy phase around 100 s period and very different surface wave seismograms compared to a model with no lvz even a single observation of long period surface waves from a known range can be diagnostic of the lithospheric structure

timing of deformation in overthrust belt and foreland of idaho wyoming and utah a review of the timing and displacement evidence of the major structures of the western wyoming overthrust belt and foreland shows there is a progression in thrust displacement apparent duration of motion and palinspastic position of thrust traces from west to east those toward the west moved farther for an apparently longer period of time and are more widely spaced in their restored positions than those toward the east however average thrust velocities are all on the order of 0 5 0 5 cm yr 0 2 in yr foreland events are in part synchronous with thrust belt events and had an effect on them although dating precision varies widely on major normal faults present evidence does not contradict the generally held view that all normal faults postdate the youngest thrusting

thermal history of sedimentary basins maturation indices and kinetics of oil and gas generation temperature is the most sensitive parameter in hydrocarbon generation thus reconstruction of temperature history is essential when evaluating petroleum prospects no measurable parameter can be directly converted to paleotemperature maturation indices such as vitrinite reflectance tmax from rock eval pyrolysis spore coloration thermal alteration index tai or concentration of biological markers offer an indirect approach all these indices are a function of the thermal history through rather complex kinetics frequently influenced by the type of organic matter their significance and validity are reviewed besides the problems of identification e g vitrinite and interlaboratory calibration it is important to simultaneously interpret kerogen type and maturation and to avoid difficult conversions from one index to another geodynamic models where structural and thermal histories are connected are another approach to temper ture reconstruction which could be calibrated against the present distribution of temperature and the present value of maturation indices kinetics of kerogen decomposition controls the amount and composition of hydrocarbons generated an empirical time temperature index tti originally introduced by lopatin does not allow such a quantitative evaluation due to several limitations no provision for different types of kerogen and different rates of reactions poor calibration on vitrinite reflectance it is of limited interest unless one has no access to a desk top computer kinetic models based on a specific calibration made on actual source rock samples can simulate the evolution of all types of organic matter and can provide a quantitative evaluation of oil and gas generated examples from the jurassic source rocks of the paris basin monterey formation of california green river shales of utah paleozoic source eds of the algerian sahara and miocene rocks of the mahakam delta indonesia illustrate various aspects of the discussion geological geochemical models are the most efficient way to integrate geological seismic and geochemical data and they should greatly help to reduce the risk in exploration

determination of thermal conductivity for deep boreholes two methods for thermal conductivity determinations on rock cores and fragments were tested on a suite of samples from the kontinentales tiefbohrprogramm der bundesrepublik deutschland ktb superdeep drill hole in germany they were also compared with estimates of thermal conductivity using the mineral composition of the rock and physical well logs and with in situ thermal conductivity measurements laboratory methods provide reasonably precise determinations of the thermal conductivities of both solid core 5 and drill cuttings 10 at room temperature and pressure the most common methods presently used for crystalline rocks are the steady state divided bar db technique and the transient half space line source ls sample preparation and measurement times are comparable for the db and ls with sample preparation being more time consuming on average for isotropic rocks there is little to choose from between the two methods which both give reliable values of conductivity in the vertical direction the ls is easier to set up and use in field laboratory situations which renders it the preferred method for field reconnaissance the gneissic crystalline rocks penetrated by the ktb boreholes typically have anisotropy of the order of 10 20 the db provides unambiguous values of conductivity in a given direction so its use is preferable for obtaining both principal conductivities and the vertical component anisotropy can be estimated using ls measurements in many different directions but the potential for large random errors is much greater than with the more straightforward db approach for deep research wells the difficulties of extrapolating laboratory results to in situ conditions particularly temperature present additional obstacles to determining heat flow laboratory measurements of water saturated samples under in situ conditions combined with in situ measurements and judicious use of calculations based on mineralogy and well log derived physical properties can aid in the accurate characterization of thermal conductivity in deep wells the application of different methods helped to link variations of heat flow with depth in the ktb hole to the anisotropy of thermal conductivity or thermal refraction and thus allowed the calculation of background heat flux in this geologically complex area

recent seismicity in valles marineris mars insights from young faults landslides boulder falls and possible mud volcanoes abstract current seismicity of mars is poorly known geodynamic models and analysis of surface faults indicate that mars could be seismically active globally particularly within the tharsis region however published geologic constraints on such activity are sparse in this study we use geomorphologic observations and crater size frequency age determinations gleaned from high resolution orbiter data to demonstrate that the valles marineris region is recently seismo tectonically active the chasmata shows evidence of reactivated dip slip faults that cross cut the chasmata walls and floors and indicates up to 1 2 km total vertical displacement along the trough bounding faults more than 16000 boulder fall occurrences with pristine trails are observed throughout the chasmata wall with an average slope of 25 degrees the boulder falls are interpreted to have been triggered by recent seismic shaking from the shallow marsquakes occurring along the chasmata faults possibly in the last thousands of years synthetic ground motion models indicate several m w 4 6 marsquakes at shallow depths 1 6 km are required to produce these canyon wide boulder falls in addition the presence of many young landslides 22 790 ma proximal to the reactivated trough bounding faults and formation of thousands of possible mud volcanic cones throughout the chasmata floor all suggest marsquake triggered shaking in the past tens to hundreds of million years corresponding to late to middle amazonian epochs we estimate formation of 20 m to 1 3 km diameter fresh impact craters around the chasmata had negligible contribution to the recent seismicity therefore valles marineris tectonism is an important source of marsquakes that may be readily detectable by the upcoming insight seismometers

inversion of bottom hole temperature data the pineview field utah wyoming thrust belt the present day temperature field in a sedimentary basin is a constraint on the maturation of hydro carbons this temperature field may be estimated by inverting corrected bottom hole temperature bht data thirty two bhts from the pineview oil field are corrected for drilling disturbances by a horner plot and inverted for the geothermal gradient in nine formations both least squares l2 norm and uniform l1 norm inversions are used the l1 norm is found to be more robust for the pineview data the inversion removes random error from the corrected bht data by partitioning scatter between noise associated with the bht measurement and correction processes and local variations in the geothermal gradient three hundred thermal conductivity and density measurements on drill cuttings are used together with formation density logs to estimate the in situ thermal conductivity of six of the nine formations the thermal conductivity estimates are used in a finite element model to evaluate 2 d conductive heat r

relationships between thermal maturity indices calculated using arrhenius equation and lopatin method implications for petroleum exploration thermal maturity can be calculated with time temperature indices tti based on the arrhenius equation using kinetics applicable to a range of types ii and iii kerogens these ttis are compared with tti calculations based on the lopatin method and are related theoretically and empirically via vitrinite reflectance to the petroleum generation window the ttis for both methods are expressed mathematically as integrals of temperature combined with variable linear heating rates for selected temperature intervals heating rates control the thermal maturation trends of buried sediments relative to arrhenius ttis lopatin ttis tend to underestimate thermal maturity at high heating rates and overestimate it as low heating rates complex burial histories applicable to a range of tectonic environments illustrate the different exploration decisions that might be made on the basis of independent results of these two thermal maturation models

tectonic history from vitrinite reflectance summary the degree of organic metamorphism of carbonaceous matter is expressed in terms of the reflectance of vitrinite vitrinite reflectance is a function of temperature and time a model relating vitrinite reflectance to temperature and time is proposed from published vitrinite reflectance temperature time nomograms a plot of the logarithm of vitrinite reflectance versus depth gives a linear curve for vitrinite reflectance greater than 0 3 per cent in a sedimentary basin which has had a constant geothermal gradient throughout its tectonic history the geothermal gradient c km 1 is equal to the slope of the curve multiplied by 194 8 the model is also applied to sedimentary basins with decreasing geothermal gradient with time i e cooling continental margin basins the vitrinite reflectance model is demonstrated to be consistent with observed reflectance data and tectonic information from the sydney bowen surat and gippsland basins in eastern australia

initial results from the insight mission on mars nasa s insight interior exploration using seismic investigations geodesy and heat transport mission landed in elysium planitia on mars on 26 november 2018 it aims to determine the interior structure composition and thermal state of mars as well as constrain present day seismicity and impact cratering rates such information is key to understanding the differentiation and subsequent thermal evolution of mars and thus the forces that shape the planet s surface geology and volatile processes here we report an overview of the first ten months of geophysical observations by insight as of 30 september 2019 174 seismic events have been recorded by the lander s seismometer including over 20 events of moment magnitude mw 3 4 the detections thus far are consistent with tectonic origins with no impact induced seismicity yet observed and indicate a seismically active planet an assessment of these detections suggests that the frequency of global seismic events below approximately mw 3 is similar to that of terrestrial intraplate seismic activity but there are fewer larger quakes no quakes exceeding mw 4 have been observed the lander s other instruments two cameras atmospheric pressure temperature and wind sensors a magnetometer and a radiometer have yielded much more than the intended supporting data for seismometer noise characterization magnetic field measurements indicate a local magnetic field that is ten times stronger than orbital estimates and meteorological measurements reveal a more dynamic atmosphere than expected hosting baroclinic and gravity waves and convective vortices with the mission due to last for an entire martian year or longer these results will be built on by further measurements by the insight lander geophysical and meteorological measurements by nasa s insight lander on mars reveal a planet that is seismically active and provide information about the interior surface and atmospheric workings of mars

generalised failure envelope for laterally loaded piles analytical formulation numerical verification and experimental validation the lateral resistance of pile foundations to combined horizontal and moment loading was examined by means of numerical analyses and experimental tests initially broms theory for the lateral cap

estimation of the global amount of submarine gas hydrates formed via microbial methane formation based on numerical reaction transport modeling and a novel parameterization of holocene sedimentation this study provides new estimates for the global offshore methane hydrate inventory formed due to microbial ch4 production under quaternary and holocene boundary conditions a multi 1d model for particular organic carbon poc degradation gas hydrate formation and dissolution is presented the novel reaction transport model contains an open three phase system of two solid compounds organic carbon gas hydrates three dissolved species methane sulfates inorganic carbon and one gaseous phase free methane the model computes time resolved concentration profiles for all compounds by accounting for chemical reactions as well as diffusive and advective transport processes the reaction module builds upon a new kinetic model of poc degradation which considers a down core decrease in reactivity of organic matter various chemical reactions such as organic carbon decay anaerobic oxidation of methane methanogenesis and sulfate reduction are resolved using appropriate kinetic rate laws and constants gas hydrates and free gas form if the concentration of dissolved methane exceeds the pressure temperature and salinity dependent solubility limits of hydrates and or free gas with a rate given by kinetic parameters global input grids have been compiled from a variety of oceanographic geological and geophysical data sets including a new parameterization of sedimentation rates in terms of water depth we find prominent gas hydrate provinces offshore central america where sediments are rich in organic carbon and in the arctic ocean where low bottom water temperatures stabilize methane hydrates the world s total gas hydrate inventory is estimated at 0 82 x 10sup13 m3 2 10 x 10sup15 m3 ch4 at stp conditions or equivalently 4 18 995 gt of methane carbon the first value refers to present day conditions estimated using the relatively low holocene sedimentation rates the second value corresponds to a scenario of higher quaternary sedimentation rates along continental margins our results clearly show that in situ poc degradation is at present not an efficient hydrate forming process significant hydrate deposits in marine settings are more likely to have formed at times of higher sedimentation during the quaternary or as a consequence of upward fluid transport at continental margins

thermal histories and hydrocarbon generation example from utah wyoming thrust belt the thermal history of the utah wyoming thrust belt in the vicinity of the pineview oil and gas field is studied with a detailed thermal model the model incorporates a heterogeneous thermal conductivity structure radioactive heat generation in the crust sediment compaction variable basal heat flow through time and thermal effects of sedimentation erosion and thrust faulting the analysis is constrained by 206 corrected bottom hole temperatures 660 thermal conductivity measurements and 10 new vitrinite reflectance measurements present surface heat flow in this part of the utah wyoming thrust belt is estimated to be 60 8 mw m2 surface heat flow in the late cretaceous about 70 ma is inferred to have been 38 8 mw m2 from an lysis of vitrinite reflectance data about half of the apparent difference between ancient and present surface heat flow may be attributed to transient thermal effects of sedimentation erosion and thrusting the hypothesis of a constant background thermal state in this part of the thrust belt for the last 70 m y may not be ruled out however thermal history simulations in which the background thermal state changes through time better match constraints imposed by estimated present surface heat flow and vitrinite reflectance data application of the thermal history analysis to hydrocarbon generation is illustrated with a kinetic model of organic maturation oil and gas at the pineview field may have been generated in two stages first stage just before and during thrusting and the second stage during cenozoic warming

thermal conductivity of wilcox and frio sandstones in south texas gulf of mexico basin thermal conductivity and petrographic data are presented for verifying mechanistic models of sandstone thermal conductivity we measured the thermal conductivity of 83 wilcox and frio sandstones from south texas in the gulf of mexico sedimentary basin and correlated conductivity to petrographic variables thermal conductivities of water saturated sandstones at 20 c 68 f and 3 mpa 435 psi were measured on core plugs using a divided bar apparatus thermal conductivity ranges from 2 06 to 5 73 w m k over a porosity range of 2 4 to 29 6 because of a higher quartz content wilcox sandstones at a given porosity are more conductive than frio sandstones a grain matrix conductivity of 5 9 w m k is estimated for wilcox sandstones matrix conductivity is adequately described with an arithmetic mixing model thermal conductivities of clean 35 of the solids sandstones the dependence on quartz content can be dropped and thermal conductivities can be predicted with a linear decrease in conductivity with increasing porosity these sandstones appear isotropic with respect to thermal conductivity

mars chronology assessing techniques for quantifying surficial processes abstract currently the absolute chronology of martian rocks deposits and events is based mainly on crater counting and remains highly imprecise with epoch boundary uncertainties in excess of 2 billion years answers to key questions concerning the comparative origin and evolution of mars and earth will not be forthcoming without a rigid martian chronology enabling the construction of a time scale comparable to earth s priorities for exploration include calibration of the cratering rate dating major volcanic and fluvial events and establishing chronology of the polar layered deposits if extinct and or extant life is discovered the chronology of the biosphere will be of paramount importance many radiometric and cosmogenic techniques applicable on earth and the moon will apply to mars after certain baselines e g composition of the atmosphere trace species chemical and physical characteristics of martian dust are established the high radiation regime may pose a problem for dosimetry based techniques e g luminescence the unique isotopic composition of nitrogen in the martian atmosphere may permit a mars specific chronometer for tracing the time evolution of the atmosphere and of lithic phases with trapped atmospheric gases other mars specific chronometers include measurement of gas fluxes and accumulation of platinum group elements pge in the regolith putting collected samples into geologic context is deemed essential as is using multiple techniques on multiple samples if in situ measurements are restricted to a single technique it must be shown to give consistent results on multiple samples but in all cases using two or more techniques e g on the same lander will reduce error while there is no question that returned samples will yield the best ages in situ techniques have the potential to be flown on multiple missions providing a larger data set and broader context in which to place the more accurate dates

seismic energy release of the moon previous estimates of the seismic energy released by lunar events have not properly accounted for instrument bandwidth variations in corner frequency and the effects of intense scattering in this paper equations are developed that include all of these effects and give realistic estimates for source parameters these equations are applied to seismograms and displacement spectra from near surface and deep moonquakes to obtain m0 seismic moment s seismic energy release eyr seismic energy released annually by each lunar event class stress drop and mb body wave magnitude the calculations yield m0 3 1021 dyn cm s 2 1017 ergs 400 bars and mb 5 0 for the largest shallow moonquakes and m0 5 1020 dyn cm s 1 1013 ergs 0 1 bars and mb 3 0 for large deep events the average energy released annually is eyr 2 1017 erg yr and eyr 8 1013 erg yr by shallow and deep events respectively overall lunar energy release is dominated by the shallow events the energy released by the deep events may be accounted for by tidal dissipation and deep event stress drops are comparable to and smaller than the calculated tidal stresses a comparison of the above values with those observed terrestrially eyr 1025 ergs and with the energy available from heat flow and tidal dissipation emphasizes the importance of tectonic style e g plate tectonics in determining the characteristics of planetary seismicity

interior structure of terrestrial planets modeling mars mantle and its electromagnetic geodetic and seismic properties 1 we present a new procedure to describe the one dimensional thermodynamical state and mineralogy of any earth like planetary mantle with mars as an example the model parameters are directly related to expected results from a geophysical network mission in this case electromagnetic geodetic and seismological processed observations supplemented with laboratory measurements we describe the internal structure of the planet in terms of a one dimensional model depending on a set of eight parameters for the crust the thickness and the mean density for the mantle the bulk volume fraction of iron the olivine volume fraction the pressure gradient and the temperature profile and for the core its mass and radius currently available geophysical and geochemical knowledge constrains the range of the parameter values in the present paper we develop the forward problem and present the governing equations from which synthetic data are computed using a set of parameter values among all martian models fitting the currently available knowledge we select eight candidate models for which we compute synthetic network science data sets the synergy between the three geophysical experiments of electromagnetic sounding geodesy and seismology is emphasized the stochastic inversion of the synthetic data sets will be presented in a companion paper

thrust loads and foreland basin evolution cretaceous western united states two dimensional modeling of loading during the formation of the idaho wyoming thrust belt shows that regional isostatic compensation by flexure of an elastic lithosphere is sufficient to control the formation of a foreland basin the flexural rigidity of the lithosphere is inferred to have been approximately 1023 nm 1030 dyne cm on the basis of palinspastic comparison of predicted downwarping due to the thrust plate loads to the shape of the sedimentary wedge on the west side of the cretaceous western interior seaway erosion of part of the uplifted thrust plates redistributed the load depositing it farther to the east thereby causing subsidence over a much wider area than could have been accomplished only by the loading by thrust plates paleotopography after major cretaceous thrust events was calculated the resulting mountainous terrain gentle alluvial plain and flat sea floor correspond well with the topography of the modern foreland thrust belt and basin system in the andes of south america and to paleogeographic reconstructions in the western united states thrust belt topography is controlled by the subsurface geometry of the thrust faults particularly the positions of ramp zones and by isostatic subsidence

a geophysical perspective on the bulk composition of mars we invert the martian tidal response and mean mass and moment of inertia for chemical composition thermal state and interior structure the inversion combines phase equilibrium computations with a laboratory based viscoelastic dissipation model the rheological model which is based on measurements of anhydrous and melt free olivine is both temperature and grain size sensitive and imposes strong constraints on interior structure the bottom of the lithosphere defined as the location where the conductive geotherm meets the mantle adiabat occurs deep within the upper mantle 250 500 km depth resulting in apparent upper mantle low velocity zones assuming an fe fes core our results indicate 1 a mantle with a mg molar mg mg fe of 0 75 in agreement with earlier geochemical estimates based on analysis of martian meteorites 2 absence of bridgmanite and ferropericlase dominated basal layer 3 core compositions 13 5 16 wt s core radii 1640 1740 km and core mantle boundary temperatures 1560 1660 c that together with the eutectic like core compositions suggest the core is liquid and 4 bulk martian compositions that are overall chondritic with a fe si wt ratio of 1 63 1 68 we show that the inversion results can be used in tandem with geodynamic simulations to identify plausible geodynamic scenarios and parameters specifically we find that the inversion results are reproduced by stagnant lid convection models for a range of initial viscosities 1019 1020 pa s and radioactive element partitioning between crust and mantle around 0 001 the geodynamic models predict a mean surface heat flow between 15 25 mw m2

verifying single station seismic approaches using earth based data preparation for data return from the insight mission to mars abstract the planned insight mission will deliver a single seismic station containing 3 component broadband and short period sensors to the surface of mars in 2016 while much of the progress in understanding the earth and moon s interior has relied on the use of seismic networks for accurate location of sources single station approaches can be applied to data returned from mars in order to locate events and determine interior structure in preparation for the data return from insight we use a terrestrial dataset recorded at the global seismic network station bfo located at the black forest observatory in germany to verify an approach for event location and structure determination based on recordings of multiple orbit surface waves which will be more favorable to record on mars than earth due to smaller planetary radius and potentially lower background noise with this approach applied to events near the threshold of observability on earth we are able to determine epicentral distance within approximately 1 corresponding to 60 km on mars and origin time within 30 s with back azimuth determined from rayleigh wave polarization absolute locations are determined generally within an aperture of 10 allowing for localization within large tectonic regions on mars with these locations we are able to recover earth mantle structure within 5 the insight mission requirements for martian mantle structure using 1d travel time inversions of p and s travel times for datasets of only 7 events the location algorithm also allows for the measurement of great circle averaged group velocity dispersion which we measure between 40 and 200 s to scale the expected reliable frequency range of the insight data from earth to mars data using the terrestrial data we are able to resolve structure down to 200 km but synthetic tests demonstrate we should be able to resolve martian structure to 400 km with the same frequency content given the smaller planetary size

predicted detection rates of regional scale meteorite impacts on mars with the insight short period seismometer abstract in 2016 nasa will launch the insight discovery class mission which aims to study the detailed internal structure of mars for the first time short and long period seismometers form a major component of insight s payload and have the potential to detect seismic waves generated by meteorite impacts large globally detectable impact events producing craters with diameters of 100 m have been investigated previously and are likely to be rare teanby n a wookey j 2011 phys earth planet int 186 70 80 but smaller impacts producing craters in the 0 5 20 m range are more numerous and potentially occur sufficiently often to be detectable on regional scales 1000 km at these distances seismic waves will have significant high frequency content and will be suited to detection with insight s short period seismometer seis sp in this paper i estimate the current martian crater production function from observations of new craters malin m c et al 2006 science 314 1573 1577 daubar i j et al 2013 icarus 225 506 516 model results williams j p pathare a v aharonson o 2014 icarus 235 23 36 and standard isochrons hartmann w k 2005 icarus 174 294 320 these impact rates are combined with an empirical relation between impact energy source receiver distance and peak seismogram amplitude derived from a compilation of seismic recordings of terrestrial and lunar impacts chemical explosions and nuclear tests the resulting peak seismogram amplitude scaling law contains significant uncertainty but can be used to predict impact detection rates i estimate that for a short period instrument with a noise spectral density of 10 8 ms 2 hz 1 2 in the 1 16 hz frequency band approximately 0 1 30 regional impacts per year should be detectable with a nominal value of 1 3 impacts per year therefore small regional impacts are likely to be a viable source of seismic energy for probing mars crustal and upper mantle structure this is particularly appealing as such impacts should be easily located with orbital imagery increasing their scientific value compared to other types of events with unknown origins finally comparison of the empirical results presented here with the modelling study of teanby and wookey teanby n a wookey j 2011 phys earth planet int 186 70 80 provides constraints on the seismic efficiency suggesting that values of 5 10 4 may be appropriate for impact generated seismic waves comparing explosion and impact datasets indicate that buried explosions are 10 times more efficient at generating seismic waves than impacts

displacements of footings on sand under eccentric and inclined loads results of an investigation of the response of footings on sand under eccentric and inclined loads are presented apparatus was constructed that could simultaneously apply loads to footings at any eccentricity and inclination without imposing restraints on the footing displacements the experimental results are interpreted compared with published data and a method for predicting vertical and horizontal displacements and rotations of loaded footings on sand developed at low load levels the analysis generates the elastic half space solution which is then augmented to provide the complete nonlinear response of the footing in addition interaction diagrams between the vertical loads horizontal loads and moments that cause failure of the footing are presented key words footing sands eccentric loading inclined loading displacement rotation bearing capacity

heat flow in the utah wyoming thrust belt from analysis of bottom hole temperature data measured in oil and gas wells bottom hole temperature bht data from oil and gas wells represent a large albeit low quality data base for heat flow determinations a method for analyzing bht data sets that directly addresses the problem of noise in the data is presented and illustrated by application to 303 bhts from the anschutz ranch ar cave creek cc and anschutz ranch east are oil gas fields in the utah wyoming thrust belt located in the middle rocky mountain physiographic province of the western united states correction of raw bht data by means of a horner plot yields 81 corrected bhts an additional 90 bhts not suitable for a horner correction are corrected by means of a new bht correction which may be applied to any single bht for which a depth and time of measurement are known the average geothermal gradient at both ar cc and are is found to be 23 c km although an average gradient analysis fails to explain scatter in the data analysis of corrected bhts through inversion of a layered earth model yields estimates of formation thermal gradients and temperature fields at ar cc and are that are stable and unique with an average precision of 2 to 3 c thermal conductivity measurements were made on 360 drill cutting samples representing 14 thrust belt formations in situ conductivity is estimated using porosity from calibrated well logs heat flow is estimated by comparing temperature calculated by a two dimensional finite element model with temperature estimated from analysis of bht data analysis of bht data from the ar cc area yields an estimated regional heat flow of 60 mw m2 8 mw m2 a similar analysis at are results in an estimate of 58 mw m2 8 mw m2 these estimates are close to values determined for the wyoming basin and the central colorado plateau and imply that a thermal transition from the middle rocky mountains to elevated heat flow characteristic of the basin and range province 80 to 90 mw m2 must take place within 50 km

a probabilistic framework for single station location of seismicity on earth and mars abstract locating the source of seismic energy from a single three component seismic station is associated with large uncertainties originating from challenges in identifying seismic phases as well as inevitable pick and model uncertainties the challenge is even higher for planets such as mars where interior structure is a priori largely unknown in this study we address the single station location problem by developing a probabilistic framework that combines location estimates from multiple algorithms to estimate the probability density function pdf for epicentral distance back azimuth and origin time each algorithm uses independent and complementary information in the seismic signals together the algorithms allow locating seismicity ranging from local to teleseismic quakes distances and origin times of large regional and teleseismic events m 5 5 are estimated from observed and theoretical body and multi orbit surface wave travel times the latter are picked from the maxima in the waveform envelopes in various frequency bands for smaller events at local and regional distances only first arrival picks of body waves are used possibly in combination with fundamental rayleigh r1 waveform maxima where detectable depth phases such as pp or pmp help constrain source depth and improve distance estimates back azimuth is determined from the polarization of the rayleigh and or p wave phases when seismic signals are good enough for multiple approaches to be used estimates from the various methods are combined through the product of their pdfs resulting in an improved event location and reduced uncertainty range estimate compared to the results obtained from each algorithm independently to verify our approach we use both earthquake recordings from existing earth stations and synthetic martian seismograms the mars synthetics are generated with a full waveform scheme axisem using spherically symmetric seismic velocity density and attenuation models of mars that incorporate existing knowledge of mars internal structure and include expected ambient and instrumental noise while our probabilistic framework is developed mainly for application to mars in the context of the upcoming insight mission it is also relevant for locating seismic events on earth in regions with sparse instrumentation

the art of maturity modeling part 2 alternative models and sensitivity analysis the sensitivity of exploration decisions to variations in several input parameters for maturity modeling was examined for the miti rumoi well hokkaido japan decisions were almost completely insensitive to uncertainties about formation age and erosional removal across some unconformities but were more sensitive to changes in removal during unconformities which occurred near maximum paleotemperatures exploration decisions were not very sensitive to the choice of a particular kinetic model for hydrocarbon generation uncertainties in kerogen type and the kinetics of different kerogen types are more serious than differences among the various kinetic models results of modeling using the tti method were unsatisfactory thermal history and timing and amount of hydrocarbon generation estimated or calculated using the tti method were greatly different from those obtained using a purely kinetic model we strongly recommend use of the kinetic r o method instead of the tti method if we had lacked measured r o data subsurface temperature data or both our confidence in the modeling results would have been sharply reduced conceptual models for predicting heat flow and thermal conductivity are simply too weak at present to allow us to carry out highly meaningful modeling unless our input is constrained by measured data maturity modeling therefore requires the use of more not fewer measured temperature and maturity data the use of sensitivity analysis in maturity modeling is very important for understanding the geologic system for knowing what level of confidence to place on the results and for determining what new types of data would be most necessary to improve our confidence sensitivity analysis can be carried out easily using a rapid interactive maturity modeling program

interrelation between rifting faulting sedimentation and mantle serpentinization during continental margin formation including examples from the norwegian sea the conditions permitting mantle serpentinization during continental rifting are explored within 2 d thermotectonostratigraphic basin models which track the rheological evolution of the continental crust account for sediment blanketing effects and allow for kinetically controlled mantle serpentinization processes the basic idea is that the entire extending continental crust has to be brittle for crustal scale faulting and mantle serpentinization to occur the isostatic and latent heat effects of the reaction are fully coupled to the structural and thermal solutions a systematic parameter study shows that a critical stretching factor exists for which complete crustal embrittlement and serpentinization occurs increased sedimentation rates shift this critical stretching factor to higher values as sediment blanketing effects result in higher crustal temperatures sediment supply has therefore through the temperature dependence of the viscous flow laws strong control on crustal strength and mantle serpentinization reactions are only likely when sedimentation rates are low and stretching factors high in a case study for the norwegian margin we test whether the inner lower crustal bodies lcb imaged beneath the more and voring margin could be serpentinized mantle multiple 2 d transects have been reconstructed through the 3 d data set by scheck wenderoth and maystrenko 2011 we find that serpentinization reactions are possible and likely during the jurassic rift phase predicted thicknesses and locations of partially serpentinized mantle rocks fit to information on lcbs from seismic and gravity data we conclude that some of the inner lcbs beneath the norwegian margin may be partially serpentinized mantle

analysis of temperatures in sedimentary basins the michigan basin we develop an analytical and numerical methodology for the analysis of large bottom hole temperature bht data sets from sedimentary basins and test the methodology using temperature stratigraphic and lithologic data from 411 boreholes in the michigan basin least squares estimates of temperature gradients in the formations and lithologies present are calculated as solutions to a large system of linear equations at each borehole the temperature difference between the bottom and top of the hole is represented as a sum of temperature increments through the various formations or lithologies penetrated by the borehole quadratic programming techniques enable bounds to be placed on the gradient solutions in order to suppress or exclude improbable gradient estimates numerical experiments with synthetic data reveal that the estimates of temperature gradients for a given formation or lithology are sensitive to the degree of representation of that unit well represented units have more stable gradient estima

subaqueous shrinkage cracks in the sheepbed mudstone implications for early fluid diagenesis gale crater mars the sheepbed mudstone yellowknife bay formation gale crater represents an ancient lakebed now exhumed and exposed on the martian surface the mudstone has four diagenetic textures including a suite of early diagenetic nodules hollow nodules and raised ridges and later diagenetic light toned veins that crosscut those features in this study we describe the distribution and characteristics of the raised ridges a network of short spindle shaped cracks that crosscut bedding do not form polygonal networks and contain two to four layers of isopachous erosion resistant cement the cracks have a clustered distribution within the sheepbed member and transition laterally into concentrations of nodules and hollow nodules suggesting that these features formed penecontemporaneously because of the erosion resistant nature of the crack fills their three dimensional structure can be observed cracks that transition from subvertical to subhorizontal orientations suggest that the cracks formed within the sediment rather than at the surface this observation and comparison to terrestrial analogs indicate that these are syneresis cracks cracks that formed subaqueously syneresis cracks form by salinity changes that cause sediment contraction mechanical shaking of sediment or gas production within the sediment examination of diagenetic features within the sheepbed mudstone favors a gas production mechanism which has been shown to create a variety of diagenetic morphologies comparable to the raised ridges and hollow nodules the crack morphology and the isopachous layered cement fill show that the cracks were filled in the phreatic zone and that the sheepbed mudstone remained fluid saturated after deposition and through early burial and lithification

thermal and maturation modeling of the urengoy field west siberian basin some special considerations in basin modeling present day temperature and vitrinite reflectance ro profiles are considered key factors for calibration in numerical basin modeling therefore it is important to understand how such profiles are generated basin modeling typically considers factors such as rock consolidation depth variation of petrophysical characteristics changes in heat flow and paleoclimate however our basin evaluations have shown that other processes that influence temperature and ro vitrinite reflectance profiles commonly are inadequately studied modeling within the urengoy field of the west siberian basin has allowed numerical estimates of some of these nonstandard processes first a substantial increase in temperature up to 5 10ic is expected from changes in heat conductivity due to the formation of significant free gas gas condensate and condensate second climate variations creating numerous periods of formation and degradation of permafrost zones for the last 3 4 m y could decrease the modern rock temperatures by 10 17ic in the upper 1 5 km of the sedimentary section and up to 10ic at its base due to the short duration of these two processes their effect on organic matter maturation is minimal nevertheless their roles in the formation of present day temperature profiles necessitate their inclusion in basin modeling third modeling results demonstrated that change in heat conductivity of rocks with dispersed organic matter can increase temperature of sedimentary rocks by 3 5ic and rock maturity by not more than 0 02 ro finally the sharp increase in vitrinite reflectance ro with depth typical for the deep sedimentary units of the urengoy field and many other continental rift basins is possible to explain from hydrothermal activity the influence of these processes on subsurface temperatures and maturation of organic matter can vary significantly depending on lithology organic matter content and the location of the modeled section relative to the ancient rift system the results of this study can help one estimate the relative influence of these parameters

tectonic history of the syria planum province of mars we attribute most of the development of extensive fractures in the tharsis region to discrete tectonic provinces within the region rather than to tharsis as a single entity one of these provinces is in syria planum faults and collapse structures in the syria planum tectonic province on mars are grouped into 13 sets based on relative age areal distribution and morphology according to superposition and fault crosscutting relations and crater counts we designate six distinct episodes of tectonic activity in the following chronologic order stage i is an early to late noachian deformation forming mostly east west structures fault set ia some large volcanoes also formed faults were produced possibly by flexural uplift also arcuate north trending grabens set ib indicate that faulting is transitional to the next stage stage ii is late noachian to early hesperian radial faulting centered in syria planum possibly due to isostatic uplift in late noachian set iia to early hesperian set iib time stage iii is early to late hesperian faulting tangential to syria planum that was related to local centers of uplift sets iii1 iii3 on the periphery of syria planum stage iv is a late hesperian graben formation that was circumferential to syria planum set iva caused either by collapse associated with eruption of magma or by flexure of the lithosphere due to volcanic loading in association with volcanism minor faulting occurred producing an oval pattern of faults in southwest syria planum set ivbl and a radial pattern south of the planum set ivb2 that apparently rejuvenated buried stage ii faults stage v is a late hesperian to early amazonian development of grabens and troughs of noctis labyrinthus and western valles marineris set v that was probably instigated by local uplift exposure of groundwater or ground ice zones may have produced further collapse and trough enlargement stage vi is early amazonian northwest trending faulting in noctis fossae set vil perhaps due to tharsis monies centered tectonism and north northwest normal faulting along the eastern side of the claritas rise set vi2 that was due to tectonic subsidence the duration of tectonic activity in the syria planum province was perhaps 2 3 b y photoclinometric topographic profiles across 132 grabens and fault scarps show that syria planum grabens have widths average of 2 5 km and most range from 1 to 6 km similar to lunar grabens but the martian grabens have slightly higher side walls average about 132 m and gentler wall slopes average of 9 and range of 2 25 than lunar grabens 93 m high and 18 slopes scarp degradation on mars has progressed through quakes impact shaking and dry slope processes the lower slopes may be due to mars higher gravity estimates of the amount of extension for individual grabens range from 20 to 350 m most estimates of the thickness of the faulted layer range from 0 5 to 4 5 km average is 1 5 km this thickness range corresponds closely to the 0 8 to 3 6 km range in depth for pits troughs and canyons in noctis labyrinthus and along the walls of valles marineris we propose that the predominant 1 to 1 5 km values obtained for both the thickness of the faulted layer and the depths of the pits troughs and theater heads of the canyons reflect the initial depth to the water table in this region as governed by the depth to the base of ground ice maximum depths for these features may indicate lowered groundwater table depths and the base of ejecta material

displacement length scaling for terrestrial and martian faults implications for valles marineris and shallow planetary grabens the displacement length ratio for the central composite graben in valles marineris inferred from topography and likely stratigraphic offsets to be d max l 4 6 x 10 3 is consistent with the scaling relations derived from terrestrial faults and grabens that also demonstrate a systematic variation in displacement with position along the structure the large 10 km depth in central valles marineris is therefore not unusual but rather should be expected for a fault system 2240 km long in contrast existing measurements of throw along the numerous shallow radial grabens in tharsis while apparently inconsistent with the scaling relations demonstrate the importance of recognizing mechanical segment length along linked or echelon graben sets faults on other planetary surfaces should scale with their terrestrial counterparts as long as they extend substantially deeper than the gravity dependent near surface rock mass zone 1 km for earth 2 5 km for mars

numerical assessment of the effects of topography and crustal thickness on martian seismograms using a coupled modal solution spectral element method abstract the past 4 decades of mars exploration have provided much information about the mars surface when its interior structure remains relatively poorly constrained today available data are compatible with a large range of model parameters seismology is able to provide valuable additional data but the number of seismographs will likely be quite limited specially in the early stage of future mars seismic networks it is thus of importance to be able to correctly isolate effects induced by the crust structure mars topography is characterized by spectacular reliefs like the tharsis bulge or the hellas basin and by the so called mars dichotomy the north hemisphere is made up of low altitude plains above a relatively thin crust when the south hemisphere is characterized by a thick crust sustaining high reliefs the aim of this paper is to study the effects induced on seismograms by the topography of the surface and crust mantle discontinuities synthetic seismograms were computed using the coupled spectral element modal solution method which reduces the numerical cost by limiting the use of the spectral element method to the regions where lateral variations like the presence of a topography are considered due to numerical cost this study is limited to long period and thus focuses on surface waves mainly on long period rayleigh waves we show that reliefs like the tharsis bulge or the hellas basin can induce an apparent velocity anomaly up to 0 5 when only the surface topography is introduced apparent anomalies can raise up to 1 0 when the surface topography is fully compensated by a mirror image topography of the crust mantle discontinuity travel time of surface wave are systematically increased for seismometers in the north hemisphere of mars and decreased in the south hemisphere when comparing effects on seismograms by the earth and mars topography we found them to be larger for the earth it is due to the fact that we work with a seismic velocity model of mars with a mean crust thickness of 110 km when the crust thickness has a mean value of 50 km for the earth when changing the mars model for a thinner crust with a mean thickness of 50 km effects by the topography on mars seismograms becomes of the same order when not larger than what is observed on the earth

unusually high stress drops associated with shallow moonquakes new estimates of stress drops and energy release associated with shallow moonquakes believed to represent the only lunar seismic events of tectonic origin have been made taking into account 1 properties of source spectra 2 radiation pattern of foci 3 anelastic attenuation of seismic waves 4 response of the seismometer and 5 intense scattering of seismic signals the results indicate that the three largest events show body wave magnitudes of mb 5 5 and stress drops of 100 mpa the values for stress drops are high compared with those generally associated with most terrestrial events but they are compatible with results predicted from thermoelastic models of the moon presence of high stresses in the lunar crust may indicate that at the beginning of its history the moon was originally molten not only in the outer surface region but throughout its whole volume

the search for active marsquakes using subpixel coregistration and correlation best practice and first results the state of seismic activity on mars is currently unknown on earth coseismic displacement has been observed using visible wavelength images and subpixel coregistration and correlation techniques we apply this method to mars with the cosi corr co registration of optically sensed images and correlation software package using high resolution imaging science experiment hirise images focusing on part of the cerberus fossae fault system we derive best practices for applying this method to the study of coseismic displacements on mars using a time series of eight overlapping hirise images we achieve pixel coregistration with a mean accuracy of about 1 50 of a pixel we see no clear evidence for coseismic displacement in this region during a time period of over 8 years one possible displacement signal 1 2 m of west east displacement over a length scale of about 50 m that has similarities to terrestrial coseismic deformation was dismissed as the result of incomplete correction of steep topography during the coregistration stage ancillary observations of recurring slope lineae rsl activity in the surrounding fault system offer no supporting evidence for the occurrence of coseismic displacement but do seem to suggest rsl activity that does not fit into previous seasonal timescales although it is unlikely that we have observed coseismic displacement in our study area during this time period the best practice method and the accuracy of our results offer encouragement for future studies hirise context camera and color and stereo surface imaging system images can be used to complement and independently verify in situ seismic observations by the insight interior exploration using seismic investigations geodesy and heat transport lander or source location changes from the exomars trace gas orbiter spacecraft

sedimentary history and mass flow structures of chryse and acidalia planitiae mars geologic mapping and crater counting in chryse and acidalia planitiae cap reveal five major sedimentary deposits of hesperian to early amazonian age including 1 a mass flow deposited during the early hesperian near deuteronilus mensae northeast of the map region that may have resulted from the carving of kasei valles 3000 km southwest of the exposed part of the deposit 2 knobby plains material consisting of channel likely from simud and tiu valles and possibly ares and shalbatana valles and mass wasting deposits in central and eastern cap 3 material largely from maja and ares valles emplaced in at least western and southern cap outcrops in southern chryse planitia developed thermokarst 4 a thin mass flow covering much of southern chryse planitia that emanated from simud and tiu valles and 5 a thick extensive perhaps 3500 km across mass flow deposit in central and northern cap derived from accumulation and backflow of the preceding thin mass flow or perhaps melting of polar deposits other possible deposits may not be recognizable owing to burial by younger materials or a lack of morphologic signature various associated landforms appear to be consistent with the mass flow interpretations including lobate and linear scarps along deposit edges fractures related to desiccation of thick sediments troughs and ridges near the edges of the deposit indicative of secondary mass movement and deformation pitted domes and fissure fed flows possibly formed by sedimentary mud eruptions and longitudinal channel grooves perhaps formed by roller vortices no convincing evidence for paleoshorelines or stagnant ice sheets is found in cap these findings suggest that mass flow and hyperconcentrated flooding may have been the predominant processes of outflow channel dissection in cap elsewhere in the northern plains similar landforms are prevalent the mass flow interpretation does not require either multiple episodes of extraordinarily high water discharge rates achieved by freeing huge volumes of water from the crust repetitive recycling of immense volumes of water into highland aquifers at the heads of chryse channels or profound climate change mars pathfinder will most likely land on and inspect the surface of the thin mass flow that originated from the canyons of simud and tiu valles

automated thermotectonostratigraphic basin reconstruction viking graben case study we present a generic algorithm for automating sedimentary basin reconstruction automation is achieved through the coupling of a two dimensional thermotectonostratigraphic forward model to an inverse scheme that updates the model parameters until the input stratigraphy is fitted to a desired accuracy the forward model solves for lithospheric thinning flexural isostasy sediment deposition and transient heat flow the inverse model updates the crustal and mantle thinning factors and paleowater depth both models combined allow for automated forward modeling of the structural and thermal evolution of extensional sedimentary basins the potential and robustness of this method is demonstrated through a reconstruction case study of the northern viking graben in the north sea this reconstruction fits present stratigraphy borehole temperatures vitrinite reflectance data and paleowater depth the predictive power of the model is illustrated through the successful identification of possible targets along the transect where the principal source rocks are in the oil and gas windows these locations coincide well with known oil and gas occurrences the key benefits of the presented algorithm are as follows 1 only standard input data are required 2 crustal and mantle thinning factors and paleowater depth are automatically computed and 3 sedimentary basin reconstruction is greatly facilitated and can thus be more easily integrated into basin analysis and exploration risk assessment

principles of geochemical prospect appraisal our current understanding of the geochemical processes responsible for the creation of commercial accumulations of oil and gas can be reduced to simple rules and equations to allow the petroleum geologist to use geochemistry to estimate before drilling the likely volumes and compositions of oil and gas delivered to the trap in most sedimentary basins oil is expelled from source rocks between 120 and 150 c whereas most gas and gas condensate are released between 150 and 230 c when the initial potential of source rocks exceeds 10kg mt oil expulsion efficiencies are between 60 and 90 expelled oil and gas migrate as petroleum rich phases driven by fluid potential gradients most flow is laterally updip in beds with effective horizontal permeabilities greater than 1 md in lower permeability rocks the petroleum fluids move vertically up or down along the path of least resistance i e the most permeable or thinnest beds separating them from a high permeability lateral carrier bed the residual saturations of petroleum left behind along the migration pathway are of the order of a few percent of the porosity geochemical analysis of source rocks helps determine the yields and compositions of petroleum fluids expelled in the catchment area of a prospect these fluid masses are converted to volumes from knowledge of the phase relations and densities of petroleum fluids evaluation of the total volume of rock through which the petroleum potentially can migrate and the mean porosity of the rocks that constitute the migration pathway allow migration losses to be assessed these losses constrain both the range of migration of petroleum fluids away from the mature source rock and the volumes of petroleum remaining for entrapment in the prospect

gas systems in the kuche depression of the tarim basin source rock distributions generation kinetics and gas accumulation history abstract six petroleum source beds have been developed in the kuche depression also known as kuqa depression of the tarim basin including three lacustrine source rocks middle and upper triassic kelamayi and huangshanjie formations and middle jurassic qiakemake formation and three coal measures upper triassic taliqike formation lower jurassic yangxia formation and middle jurassic kezilenuer formation while type i ii organic matter occurs in the middle jurassic qiakemake formation j2q other source beds contain dominantly type iii organic matter gas generation rates and stable carbon isotopic kinetics of methane generation from representative source rocks collected in the kuche depression were measured and calculated using an on line dry and open pyrolysis system combined with hydrocarbon generation history modelling the formation and evolution processes of the jurassic triassic highly efficient gas kitchens were established high sedimentation rate in the neogene and the fast deposition of the kuche formation within the pliocene 5 ma in particular have led to the rapid increase in mesozoic source rock maturity resulting in significant dry gas generation the extremely high gas generation rates from source kitchens have apparently expedited the formation of highly efficient gas accumulations in the kuche depression because different mesozoic source rocks occur in different structural belts the presence of both lacustrine and coaly gas kitchens during the cenozoic time can be identified in the kuche depression as shown by the chemical and stable carbon isotope compositions of the discovered gases the formation of the giant gas pools in the kela 2 dina 2 yaha and wucan 1 have involved very different geological processes due to the difference in their gas source kitchens

modeling petroleum generation in the southern muglad rift basin sudan maturity and petroleum generation have been modeled in a 120 km long northeast southwest cross section of the southern muglad basin sudan the section passes close to the unity and kaikang areas which provide well control on the structure interpreted from gravity and seismic reflection profiles modeling of geotherms from corrected bottom hole temperatures indicates present heat flows around 60 mw m2 in the well control areas using measured vitrinite data as calibrant maturity can be modeled equally well with a constant paleoheat flow similar to the present day or with a complex heat flow pattern related to rifting a geologically realistic complex heat flow model was employed to calculate the timing of generation and expulsion from the lower cretaceous lacustrine source rocks of the abu gabra and sharaf formations kinetic easy ro calculation of vitrinite maturity indicates a projected oil preservation depth limit around 4000 m shallowing to around 3500 m northeast of unity near the basin margin

influence of overthrusting on maturation of hydrocarbons in phosphoria formation wyoming idaho utah overthrust belt geochemical analyses were performed on 11 phosphoria formation samples collected throughout the wyoming idaho utah overthrust belt maturation models incorporating the thermal effects of thrust faulting with lopatin s techniques were then used to interpret these geochemical data in particular four of the sample sites were selected for detailed thermal modeling these four sites include one sample site in an area unaffected by thrusting two sites located in the hanging walls of major thrusts and one site in the footwall of the darby thrust the detailed thermal modeling shows overthrusting did affect the thermal history of the phosphoria formation the effect of thrusting was to cool the overriding sheet and warm the sediments being overridden thus the hanging wall samples had a different post thrusting thermal history than the footwall sample cooling of the hanging wall slowed post thrusting maturation in the two thrust sheet samples in contrast the footwall sample was exposed to higher temperatures after thrusting and the maturation process was accelerated results of this study indicate that tectonism influences the thermal history of the rocks and should be included in any reliable source rock evaluation program involving overthrust strata a simple evaluation based only on the thickness of the overburden in general will not be sufficient to explain fully the maturation data in the absence of actual geochemical information such as ro tai or cai the models described in this paper appear to be sufficiently accurate to give a reasonable estimate of thermal maturity of a potential source bed

seismic detection of meteorite impacts on mars abstract meteorite impacts provide a potentially important seismic source for probing mars interior it has recently been shown that new craters can be detected from orbit using high resolution imaging which means the location of any impact related seismic event could be accurately determined thus improving the constraints that could be placed on internal structure using a single seismic station this is not true of other seismic sources on mars such as sub surface faulting which require location using multiple seismic stations this study aims to determine the seismic detectability of meteorite impacts and assess whether they are a viable means of probing deep internal structure first we derive a relation between crater diameter and equivalent seismic moment based on observational data compiled from impact tests controlled explosions and earthquake seismology second this relation was combined with updated cratering rates based on newly observed craters to derive the impact induced seismicity on mars which we estimate to total 10 13 10 14 n m per year finally seismic waveform modelling was used to determine the detectability of these impacts based on reasonable assumptions about likely seismometer performance and background noise levels for our nominal noise instrument case we find that detectable impacts at teleseismic distances source receiver offsets greater than 60 are very rare and occur approximately once every 10 years for our most optimistic noise instrument case approximately one such event occurs each year this suggests that using solely meteorite impacts is not a reliable way of probing the martian interior although local impacts are more frequently detectable and could provide important constraints on near surface seismic properties

lunar subsurface investigated from correlation of seismic noise by correlating seismic noise recorded by four sensors placed on the moon during the apollo 17 mission we have retrieved a well defined dispersed rayleigh wave pulse inversion of its group velocity provides new constraints on the lunar subsurface structure the estimated signal to noise ratio snr of the retrieved rayleigh wavetrain is strongly dependent on solar illumination effectively making solar heating a source of seismic noise on the moon this result suggests that in future planetary missions it is feasible to extract information on the internal structure of extraterrestrial objects by correlating seismic noise even when natural quakes are absent

numerical reconstructions of thermal evolution of sedimentary cover and underlying lithosphere in western part of the south caspian basin abstract thermal evolution of the south caspian sedimentary basin since the upper triassic is numerically reconstructed on the example of the deepest sedimentary sections of the south apsheron and pre alborz depressions the modeling suggests thermally active mantle of the region with present day depth of the asthenosphere top of 50 60 km the temperature at the base of the sedimentary cover at depth of about 20 km is estimated by 400 to 500 c the abnormally low temperatures of sedimentary rocks in the upper 5 6 km of the present day sedimentary cover are in contrast with high temperature regime of the upper mantle in the region these low temperatures are explained by high effective thermal conductivity of the rocks in the upper 5 6 km of sedimentary cover in conditions of avalanche sedimentation it is believed that the considerable increase in effective heat conductivity of sedimentary rocks took place during the last 0 5 1 million years and can be due to contribution of the dispersional heat transfer the latter is effective in deconsolidate upper layer of sediments deposited with high rate of sedimentation during last 2 5 my

a prediction of mars seismicity from surface faulting the shallow seismicity of mars has been estimated by measurement of the total slip on faults visible on the surface of the planet throughout geologic time seismicity was calibrated with estimates based on surface structures on the moon and measured lunar seismicity that includes the entire seismogenic lithosphere results indicate that mars is seismically active today with a sufficient number of detectable marsquakes to allow seismic investigations of its interior

flank tectonics of martian volcanoes on the flanks of olympus mons is a series of terraces concentrically distributed around the caldera their morphology and location suggest that they could be thrust faults caused by compressional failure of the cone in an attempt to understand the mechanism of faulting and the possible influences of the interior structure of olympus mons we have constructed a numerical model for elastic stresses within a martian volcano in the absence of internal pressurization the middle slopes of the cone are subjected to compressional stress appropriate to the formation of thrust faults these stresses for olympus mons are 250 mpa if a vacant magma chamber is contained within the cone the region of maximum compressional stress is extended toward the base of the cone if the magma chamber is pressurized extensional stresses occur at the summit and on the upper slopes of the cone for a filled but unpressurized magma chamber the observed positions of the faults agree well with the calculated region of high compressional stress three other volcanoes on mars ascraeus mons arsia mons and pavonis mons possess similar terraces extending our analysis to other martian volcanoes we find that only these three and olympus mons have flank stresses that exceed the compressional failure strength of basalt lending support to the view that the terraces on all four are thrust faults

fault length statistics and implications of graben sets at candor mensa mars abstract the lengths of individual martian grabens from three spatially and temporally distinct regional sets are analyzed by a two dimensional window sampling method length distributions are influenced by fault growth and coalescence processes image resolution window size and the post faulting geologic history of the region cumulative length frequency distributions can be linear for graben lengths between 30 and 100 km with slopes on the area plot of 2 suggesting self similar growth of the graben array post faulting geologic processes contribute to concave cumulative length distributions on the log log plot with curtailment and truncation biases producing strongly non linear distributions for smaller and longer lengths respectively recent evidence for a positive correlation between stratigraphic throw and graben length from analogous terrestrial grabens implies that the magnitudes of throw and extensional strain may also be dependent on relative position along the martian grabens

localization of bedding plane slip and backthrust faults above blind thrust faults keys to wrinkle ridge structure a mechanically based model for wrinkle ridge development is developed that combines wrinkle ridge morphologies regional topographic offsets suggestive of subsurface thrust faults and folding of near surface layers this model provides explicit relationships between observed morphologic elements characteristic of wrinkle ridges and plausible mechanisms in the subsurface a key component that is absent in previous qualitative fault based scenarios for these structures as developed in this paper wrinkle ridges are the surface expression of anticlines that grow above a blind thrust fault as a result of both flexural slip folding of near surface strata and the nucleation and growth of echelon arrays of backthrust faults calculations of displacements both horizontal shortening and vertical uplift and coulomb stress change related to slip along blind thrust faults in the model demonstrate physically important spatial inhomogeneities in these quantities with revealing and useful implications 1 the ratio of shortening due to folding at the surface to the shortening due to faulting at depth is characteristically small for coupled wrinkle ridge blind thrust fault systems and decreases with increasing fault depth the depth of the blind thrust fault s upper tip thus profoundly influences the surface strains 2 folding and uplifted topography forming the topographic ridge are produced above the area of the slipping blind thrust fault plane horizontal and vertical deformation at the surface extend over several ridge widths or a total of at least 50 km for a 10 km wide ridge implying that topographic profiles and geologic studies must extend sufficiently far from the wrinkle ridge to fully characterize the surface deformation 3 calculations of coulomb stress changes suggest that fault slip can localize both bedding plane slip in overlying strata and new backthrust faults that propagate upward to become wrinkles on the trailing side of the ridge initiation of bedding plane slip in association with slip along the blind thrust fault likely determines whether the resulting surface structure becomes a wrinkle ridge or a lobate scarp wrinkle ridge spacing may also be related to stress changes associated with slip along the underlying blind thrust fault

deformation rates from faulting at the tempe terra extensional province mars 1 rates of deformation are estimated from exposed normal faults within the tempe terra extensional province mars through an analysis that incorporates fault segment linkage and utilizes regional observations of displacement length relationships measured from mars orbiter laser altimeter topographic data moment rates from 1014 1016 n m yr strain rates 10 12 10 11 yr 1 and rifting velocities 0 003 mm yr are comparable to rates of deformation on stable plate interiors of earth the calculated low rates of rifting may result from the poorly constrained timing of deformation on mars cumulative moment release estimates decrease linearly with time from noachian 1 1025 n m to early hesperian 6 1024 n m and late hesperian early amazonian 1 1024 these results indicate that a portion of tharsis related deformation remained localized within the tempe rift throughout much of martian history and provide important constraints for models of martian mantle convection

thermal models of thrust faulting constraints from fluid inclusion observations willard thrust sheet idaho utah wyoming thrust belt the thermal effects associated with emplacement of the willard thrust sheet within the idaho utah wyoming thrust belt have been numerically modeled fluid inclusion studies and mineralogy including illite crystallinity narrowly limit choice of permissible thermal models permissible models have initial thermal gradients between about 30 c km and 35 c km and fluid pressures less than lithostatic pressure fluid inclusions were trapped in syntectonic veins within the basal part of the willard thrust sheet and in cataclastically deformed basement within the footwall homogenization temperatures have a bimodal distribution in the willard sheet with maxima at 180 c and 260 c and a unimodal distribution in the footwall with a maximum at 200 c these temperatures along with fluid composition determine fluid density and define isochores along which the fluids were trapped illite crystallinity and mineralogy record maximum temperatures in the range of 300 c to 500 c with somewhat lower maximum temperatures in the footwall thermal models for emplacement of the willard sheet indicate that the hanging wall undergoes initial rapid cooling but the footwall undergoes initial warming due to tectonic burial later both areas undergo approximately isothermal decompression as erosion proceeds p t paths for reasonable parameter values intersect the modal isochores and are consistent with mineralogy as required for a permissible model the thermal model provides a reasonable framework for understanding the thermal history of the willard sheet the models are sensitive to thrust sheet thickness initial heat flow and thermal conductivity the thermal models are relatively insensitive to erosion history for reasonable erosion rates and to redistribution of heat producing elements for the low values typical of sedimentary rocks

thermal and maturation history of jurassic source rocks in the kuqa foreland depression of tarim basin nw china abstract kuqa foreland depression of the tarim basin is one of the largest gas production provinces in china thermal history reconstruction using vitrinite reflectance data indicates that the palaeo heat flow in kuqa depression was relatively high 50 55 mw m 2 during the mesozoic but gradually decreased during the cenozoic to reach the present value of 40 50 mw m 2 the cooling of the kuqa depression is probably attributed to the crust thickening and the rapid sedimentary rate the jurassic source rocks entered conventional oil window at 100 ma and began to generate gas at approximately 75 ma in the kelasu area thermal maturation of the jurassic source rocks accelerated significantly since 23 3 ma especially in the recent 5 2 ma in this foreland depression source rock maturation which is likely controlled mainly by burial history also influenced by the presence of fault thrusting and salt bearing formations

estimation of the seismic moment rate from an incomplete seismicity catalog in the context of the insight mission to mars we evaluate methods to estimate the global seismic moment rate of a planet from the k 1 largest events observed during a limited and possibly short time span as can be expected for example for lander missions to mars the feasibility of the approach is demonstrated with a temporary broadband seismometer that was recording in the mojave desert california for 86 days in 2014 and by application to the global centroid moment tensor cmt catalog subsets thereof and a catalog of stable continental regions seismicity from the largest event observed at goldstone alone m w approximate to 7 9 we estimate the earth s global moment rate to be 1 03 x 10 22 n m yr whereas an estimation based on the 10 strongest events yields a rate of 5 79 x 10 21 n m yr summation of 42 yr of global cmt solutions results in an average of 7 61 x 10 21 n m yr in general a 2 yr interval of global cmt solutions is sufficient to estimate the earth s annual moment rate to within a factor of 5 or better a series of numerical experiments with more than 560 million synthetic catalogs based on the tapered gutenberg richter distribution shows that the estimation is rather insensitive against an unknown slope of the distribution and that bias and variance of the estimator depend on the ratio between moment rate and corner moment of the size frequency distribution moment rates of published mars models differ by a factor of 1000 or more tests with simulated catalogs show that it will be possible to reject some of these models with data returned by nasa s insight mission after two years of nominal mission life time