thermal infrared spectra of the moon contrary to recent assertions in the literature lunar emission spectra obtained at an altitude of 32 km with a balloon borne telescope are virtually undistorted by atmospheric absorption except in the ozone region these spectra have been found to correlate closely with laboratory emission spectra of returned lunar samples measured in a simulated lunar environment thus lunar spectra obtained with the balloon borne telescope system are the standards against which groundbased spectral measurements of the moon should be compared comparison of balloon borne measurements with recent groundbased spectral measurements suggests that the latter suffer from some source of systematic error when high quality lunar spectra are available they will be best interpreted by comparison with returned lunar samples rather than terrestrial minerals or rocks because of subtle spectral differences between lunar and terrestrial minerals perhaps associated with incipient alteration of the latter

a global view of martian surface compositions from mgs tes thermal emission spectrometer tes data from the mars global surveyor mgs are used to determine compositions and distributions of martian low albedo regions two surface spectral signatures are identified from low albedo regions comparisons with spectra of terrestrial rock samples and deconvolution results indicate that the two compositions are a basaltic composition dominated by plagioclase feldspar and clinopyroxene and an andesitic composition dominated by plagioclase feldspar and volcanic glass the distribution of the two compositions is split roughly along the planetary dichotomy the basaltic composition is confined to older surfaces and the more silicic composition is concentrated in the younger northern plains

feo and tio2 concentrations in the south pole aitken basin implications for mantle composition and basin formation we use newly developed spectroscopic methods for determining feo and tio2 abundances to study the huge 2500 km diameter south pole aitken basin the floor of this basin shows iron and titanium values which are weakly correlated and largely range from 7 to 14 wt feo and from 0 5 to 1 5 wt tio2 this composition is consistent with an approximate 1 1 mixture of lower crustal material like that found elsewhere on the moon and mantle rock containing 10 16 wt feo and 0 1 wt tio2 although mantle rock appears to compose about 50 of the floor deposits models of the formation of large impact basins predict that virtually all the floor materials ought to be derived from the mantle

magmatic evolution of the moon although incomplete because of the imperfect and somewhat random sampling of rock types by the apollo and luna missions 1969 1976 the history of lunar magmatism has been reconstructed by numerous researchers over the past three decades these reconstructions have illustrated the continuous nature of lunar magmatism from 4 6 to approximately 2 0 ga and the large influence of early differentiation and catastrophic bombardment on lunar mantle dynamics magmatism and eruptive style in this review we group magmatism into multiple stages of activity based on sampled rock types and evaluate the models for each stage stage 1 is early lunar differentiation and associated magmatism partial melting of the moon soon after accretion was responsible for producing an anorthositic crust and a differentiated lunar interior the extent of lunar melting and mantle processing depends strongly on the mechanisms that induced melting estimates for the time over which melting and crystallization occurred range from tens to hundreds of millions of years stage 2 is the disruption of lunar magma ocean cumulates soon after the crystallization of most of the lunar magma ocean the cumulate pile experienced gravitational overturn this resulted in transport of late forming cumulates into the deep lunar mantle and mixing of magma ocean cumulates on a variety of scales stage 3 is the post magma ocean highland magmatism whereas the ferroan anorthositic crust was probably produced during the crystallization of a magma ocean the slightly younger mg suite and alkali suite plutonic rocks may have been generated by decompressional melting of early magma ocean cumulates during cumulate pile overturn a kreep and crustal signature was incorporated into these primitive basaltic magmas through assimilation near the base of the lunar crust or through melting of a hybridized mantle the alkali suite could represent either the differentiation products of mg suite parental magmas or a separate but contemporaneous episode of basaltic magmatism stage 4 is pre basin volcanism sample analysis and remote sensing data indicate that early lunar volcanism kreep basalts and high alumina basalts was contemporaneous with periods of highlands plutonism and catastrophic bombardment of the lunar surface the relationship between early stages of lunar volcanism and the contemporaneous plutonism is not clear the kreep basalts may be volcanic equivalents to both the mg suite and alkali suite stage 5 is the late remelting of magma ocean cumulates and eruption of mare basalts basin associated eruption of mare basalts occurred during and following the late stages of catastrophic bombardment this volcanic activity was possibly an extension of the thermal event that initiated pre basin volcanism mare basalts exhibit a wide range of composition resulting from near surface fractionation of chemically distinct primary basaltic magmas most likely mare basalts were produced by small to moderate degrees of partial melting of hybrid cumulate sources in the deep lunar mantle alternatively the mixed chemical signatures observed in many mare basalts may be interpreted as indicating assimilation of late stage evolved cumulates by melts produced deep in the cumulate pile the wide range of compositions exhibited by the mare basalts compared with earlier episodes of basaltic magmatism may reflect the thermal regime in the lunar mantle that limited the extent of partial melting and melt source homogenization

non mare silicic volcanism on the lunar farside at compton belkovich non basaltic volcanism is rare on the moon and has been found predominantly on the lunar nearside analysis of lunar reconnaissance orbiter camera images and spectral data reveal the presence of compositionally evolved non basaltic volcanism on the lunar farside

generalized compact gravity inversion extending the compact gravity inversion technique by incorporating a priori information about the maximum compactness of the anomalous sources along several axes provides versatility thus the method may also incorporate information about limits in the axes lengths or greater concentration of mass along one or more directions the judicious combination of different constraints on the anomalous mass distribution allows the introduction of several kinds of a priori information about the arbitrary shape of the sources this method is particularly applicable to constant linear density sources such as mineralizations along faults and intruded sills dikes and laccoliths in a sedimentary basin the correct source density must be known with a maximum uncertainty of 40 percent otherwise the inversion produces thicker bodies for densities smaller than the true value and vice versa because of the limitations of the inverse gravity problem the proposed technique requires an empirical technique to analyze the sensitivity of solutions to uncertainties in the a priori information the proposed technique is based on a finite number of acceptable solutions presumably representative of the ambiguity region by using standard statistical techniques each parameter is assigned a coefficient measuring its uncertainty the known hematite and magnetite ore body shape in the vicinity of iron mountain mo was reproduced quite well using this inversion technique

kreep cumulates in the western lunar highlands ion and electron microprobe study of alkali suite anorthosites and norites from apollo 12 and 14 alkali suite anorthosites and norites are the second most common plutonic rock association in the western lunar highlands after the magnesian suite but their origin poses an enigma for most petrologic models of lunar crustal evolution some models suggest that the alkali and magnesian suites formed from distinct unrelated parental magmas whereas other models propose that both suites formed from the same parental magma the contrast in major element chemistry of the cumulus phases in each suite is difficult to reconcile with their similar incompatible element chemistry we present herein a detailed ion microprobe sims and electron microprobe study of seven alkali suite rocks our data show that most alkali suite anorthosites preserve major and trace element characteristics acquired during their formation as igneous cumulate rocks and that these characteristics can be used to reconstruct the parental magma composition the data indicate that cumulates of the alkali suite crystallized from magmas with rare earth element ree contents approximately 0 6 2 0xhigh k kreep and small but consistently positive eu anomalies eu eu super approximately 2 relative to kreep snyder and others 1995a have proposed that the alkali suite parental magma is similar to apollo 15 pristine kreep basalt our model suggests that the major element composition of cumulus plagioclase in most alkali suite rocks is too sodic for the calculated crystal line of descent of pristine kreep basalt and that assimilation of pre existing calcic anorthosite is required this conclusion is supported by the ree patterns of the alkali suite parental magma determined here we propose that alkali suite anorthosites formed as flotation cumulates in kreepy plutons that may have formed norites as complementary bottom cumulates the alkali flotation cumulates reflect fractional crystallization of their parental pluton local equilibrium crystallization assimilation of plagioclase rich roof rock and episodic magma mixing during convective overturn of the crystallizing magma bodies texturally pristine alkali anorthosites exhibit petrographic characteristics that are consistent with their origin as cumulates in a kreepy pluton including abundant modal plagioclase post cumulus pyroxenes both augite and pigeonite that generally lack exsolution lamellae and that have equilibration temperatures of 950 1100 degrees c relict igneous textures and in some cases igneous lamination the lack of cumulus mafic phases in rocks that should be pyroxene saturated suggests separation of the plagioclase by flotation not sinking assimilation of plagioclase from older anorthositic highlands crust is indicated by the high eu contents of the cumulates and by the positive eu anomalies in their calculated parental melts relative to high k kreep mixing of the evolved alkali suite parental magma with primitive melt occurred episodically as shown by reverse zoning profiles in some cumulus plagioclase injection of this primitive hot magma into the crystallizing pluton may have induced convective overturn of the magma chamber

the lassell massif a silicic lunar volcano abstract lunar surface volcanic processes are dominated by mare producing basaltic extrusions however spectral anomalies landform morphology and granitic or rhyolitic components found in the apollo sample suites indicate limited occurrences of non mare geochemically evolved si enriched volcanic deposits recent thermal infrared spectroscopy high resolution imagery and topographic data from the lunar reconnaissance orbiter lro show that most of the historic red spots and other less well known locations on the moon are indeed silica rich relative to basalt here we present a geologic investigation of the lassell massif 14 65 s 350 96 e near the center of alphonsus a basin in mare nubium where high silica thermal emission signals correspond with morphological indications of viscous possibly also explosive extrusion and small scale low reflectance deposits occur in a variety of stratigraphic relationships multiple layers with stair step lobate forms suggest different eruption events or pulsing within a single eruption absolute model ages derived from crater size frequency distributions csfds indicate that the northern parts of the massif were emplaced at 4 ga before the surrounding mare however csfds also indicate the possibility of more recent resurfacing events the complex resurfacing history might be explained by either continuous resurfacing due to mass wasting and or the emplacement of pyroclastics relatively low reflectance deposits are visible at meter scale resolutions below detection limits for compositional analysis at multiple locations across the massif suggestive of pyroclastic activity a quenched flow surface or late stage mafic materials compositional evidence from 7 band uv vis spectral data at the kilometer scale and morphologic evidence for possible caldera collapse and or explosive venting support the interpretation of a complex volcanic history for the lassell massif

space weathering effects in diviner lunar radiometer multispectral infrared measurements of the lunar christiansen feature characteristics and mitigation multispectral infrared measurements by the diviner lunar radiometer experiment on the lunar renaissance orbiter enable the characterization of the position of the christiansen feature a thermal infrared spectral feature that laboratory work has shown is proportional to the bulk silica content of lunar surface materials diviner measurements show that the position of this feature is also influenced by the changes in optical and physical properties of the lunar surface with exposure to space the process known as space weathering large rayed craters and lunar swirls show corresponding christiansen feature anomalies the space weathering effect is likely due to differences in thermal gradients in the optical surface imposed by the space weathering control of albedo however inspected at high resolution locations with extreme compositions and christiansen feature wavelength positions silica rich and olivine rich areas do not have extreme albedos and fall off the albedo christiansen feature wavelength position trend occupied by most of the moon these areas demonstrate that the christiansen feature wavelength position contains compositional information and is not solely dictated by albedo an optical maturity parameter derived from near ir measurements is used to partly correct diviner data for space weathering influences

possible mantle origin of olivine around lunar impact basins detected by selene the composition structure and evolution of the moon s mantle is poorly constrained a global survey of the moon s surface using the spectral profiler onboard the lunar explorer selene kaguya identifies a number of exposures of olivine in concentric regions around lunar craters with a possible mantle origin

the distribution and origin of lunar light plains around orientale basin abstract lunar light plains are relatively flat smooth to gently rolling deposits that occur in crater floors and other topographic lows in the lunar highlands with albedo values comparable to surrounding highland terrain once interpreted to be the product of highland volcanism apollo 16 samples from the light plains of the cayley formation led to the interpretation that most light plains form from the deposition of fluidized basin ejecta conflicting relative age estimates suggest that light plains are ejecta from the orientale and imbrium basins or from a larger number of impact events combined with possible volcanic eruptions here we examine the distribution variability and origin of light plains associated with the orientale basin using data from the lunar reconnaissance orbiter camera lroc we find that the distribution composition and age of the light plains to the north and northwest of the orientale basin are consistent with an origin with the formation of orientale in this case the orientale basin forming impact significantly altered the surface within four basin radii from the rim

widespread distribution of oh h 2 o on the lunar surface inferred from spectral data remote sensing data from lunar orbiters have revealed spectral features consistent with the presence of oh or h2o on the lunar surface analyses of data from the moon mineralogy mapper spectrometer onboard the chandryaan 1 spacecraft have suggested that oh h2o is recycled on diurnal timescales and persists only at high latitudes however the spatial distribution and temporal variability of the oh h2o as well as its source remain uncertain here we incorporate a physics based thermal correction into analysis of reflectance spectra from the moon mineralogy mapper and find that prominent absorption features consistent with oh h2o can be present at all latitudes local times and surface types examined this suggests the widespread presence of oh h2o on the lunar surface without significant diurnal migration we suggest that the spectra are consistent with the production of oh in space weathered materials by the solar wind implantation of h and formation of oh at crystal defect sites as opposed to h2o sourced from the lunar interior regardless of the specific composition or formation mechanism we conclude that oh h2o can be present on the moon under thermal conditions more wide ranging than previously recognized

space weathering from mercury to the asteroid belt the variety of evidence bearing on the nature of space weathering is reviewed the effects of space weathering include spectral darkening reddening and subdued absorption bands and the distinctive magnetic electron spin resonance caused by single domain metallic iron particles ever since the apollo missions two paradigms have dominated the thinking of the planetary science community concerning space weathering 1 the optical effects are caused by impact vitrified glass in agglutinates and 2 the submicroscopic metallic iron results from the reduction of ferrous iron by the impact melting of minerals whose surfaces have been saturated with hydrogen from the solar wind however studies carried out since the apollo program showed that both of these paradigms are invalid a hypothesis first suggested by the author and his colleagues 26 years ago but not generally accepted at that time now appears to be essentially correct both the optical and magnetic effects are caused by metallic iron particles smaller than the wavelength in ubiquitous vapor deposited coatings on soil particle surfaces and inside agglutinates the vapor is generated by both solar wind sputtering and micrometeorite impact vaporization and injected preferentially downward into the porous regolith the iron is reduced by a physical process the selective loss of oxygen that occurs during deposition of the vapor and does not require heating melting or a reducing environment a mathematical theory that describes the optical effects of the submicroscopic iron quantitatively is derived and applied to the regoliths of the moon mercury and an s asteroid

constraining the source regions of lunar meteorites using orbital geochemical data lunar meteorites provide important new samples of the moon remote from regions visited by the apollo and luna sample return missions petrologic and geochemical analysis of these meteorites combined with orbital remote sensing measurements have enabled additional discoveries about the composition and age of the lunar surface on a global scale however the interpretation of these samples is limited by the fact that we do not know the source region of any individual lunar meteorite here we investigate the link between meteorite and source region on the moon using the lunar prospector gamma ray spectrometer remote sensing data set for the elements fe ti and th the approach has been validated using apollo and luna bulk regolith samples and we have applied it to 48 meteorites excluding paired stones our approach is able broadly to differentiate the best compositional matches as potential regions of origin for the various classes of lunar meteorites basaltic and intermediate fe regolith breccia meteorites are found to have the best constrained potential launch sites with some impact breccias and pristine mare basalts also having reasonably well defined potential source regions launch areas for highland feldspathic meteorites are much less well constrained and the addition of another element such as mg will probably be required to identify potential source regions for these

mineralogy of the lunar crust results from clementine received 1997 december 5 accepted in revised form 1998 september 15 abstract the central peaks of 109 impact craters across the moon are examined with clementine ultraviolet visible uvvis camera multispectral data the craters range in diameter from 40 to 180 km and are believed to have exhumed material from 5 30 km beneath the surface to form the peaks including both upper and lower crustal rocks depending on whether craters have impacted into highlands or basins representative five color spectra from spectrally and spatially distinct areas within the peaks are classified using spectral parameters including key ratio which is related to mafic mineral abundance and spectral curvature linked to absorption band shape which distinguishes between low and high ca pyroxene and olivine the spectral parameters are correlated to mineralogical abundances related in turn to highland plutonic rock compositions the derived rock compositions for the various central peaks are presented in a global map from these results it is evident that the lunar crust is compositionally diverse both globally and at local 100 m scales found within individual sets of central peaks although the central peaks compositions imply a crust that is generally consistent with previous models of crustal structure they also indicate a more anorthositic crust than generally assumed with a bulk plagioclase content of 8 1 evolving from pure anorthosite near the surface towards more mafic low ca pyroxene rich compositions with depth comparable to anorthositic norite evidence for mafic plutons occurs in both highlands and basins and represent all mafic highland rock types however the lower crust is more compositionally diverse than the highlands with both a greater range of rock types and more diversity within individual sets of central peaks

highly silicic compositions on the moon using data from the diviner lunar radiometer experiment we show that four regions of the moon previously described as red spots exhibit mid infrared spectra best explained by quartz silica rich glass or alkali feldspar these lithologies are consistent with evolved rocks similar to lunar granites in the apollo samples the spectral character of these spots is distinct from surrounding mare and highlands material and from regions composed of pure plagioclase feldspar the variety of landforms associated with the silicic spectral character suggests that both extrusive and intrusive silicic magmatism occurred on the moon basaltic underplating is the preferred mechanism for silicic magma generation leading to the formation of extrusive landforms this mechanism or silicate liquid immiscibility could lead to the formation of intrusive bodies

the procellarum kreep terrane implications for mare volcanism and lunar evolution geophysical remote sensing and sample data demonstrate that the procellarum and imbrium regions of the moon make up a unique geochemical crustal province here dubbed the procellarum kreep terrane geochemical studies of imbrium s ejecta and the crustal structure of the imbrium and serenitatis basins both suggest that a large portion of the lunar crust in this locale is composed of a material similar in composition to apollo 15 kreep basalt kreep basalt has about 300 times more uranium and thorium than chondrites so this implies that a large portion of moon s heat producing elements is located within this single crustal province the spatial distribution of mare volcanism closely parallels the confines of the procellarum kreep terrane and this suggests a causal relationship between the two phenomena we have modeled the moon s thermal evolution using a simple thermal conduction model and show that as a result of the high abundance of heat producing elements that are found in the procellarum kreep terrane partial melting of the underlying mantle is an inevitable outcome specifically by placing a 10 km kreep basalt layer at the base of the crust there our model predicts that mare volcanism should span most of the moon s history and that the depth of melting should increase with time to a maximum depth of about 600 km we suggest that the 500 km seismic discontinuity that is observed in the apollo seismic data may represent this maximum depth of melting our model also predicts that the kreep basalt layer should remain partially molten for a few billion years thus the imbrium impact event most likely excavated into a partially molten kreep basalt magma chamber we postulate that the kreep basalt composition is a by product of mixing urkreep with shallow partial melts of the underlying mantle since mg suite rocks are likely derived from crystallizing kreep basalt the provenance of these plutonic rocks is likely to be unique to this region of the moon

bulk mineralogy of lunar crater central peaks via thermal infrared spectra from the diviner lunar radiometer a study of the moon s crustal composition at depth 1 the central peaks of lunar impact craters are thought to be composed of uplifted material originating from varying depths of the crustal column the interpreted crystallization sequence of the early lunar magma ocean resulted in an anorthositic upper crust that may become progressively more mafic as it approaches the olivine rich mantle emissivity spectra from the lunar reconnaissance orbiter lro diviner radiometer are used to derive the wavelength location of the christiansen feature cf which is sensitive to bulk silicate mineralogy here a survey of cf values has been performed for the central peaks of 135 complex craters providing global and regional observations of the heterogeneity of crustal compositions crustal thickness models give context to the preimpact depth of the central peak material and its proximity to the crust mantle boundary this study has identified six craters with potentially ultramafic compositions within their central peaks more common occurrences of mafic material found in a wide variety of crater central peaks show a silicate composition roughly similar to mare basalt or an olivine bearing gabbro the range of central peak cf values is similar to that of the rest of the lunar surface bulk mineralogy of the central peak material does not appear to be correlated with its crustal depth of origin suggesting both lateral and vertical heterogeneity in crustal composition rather than a gradual transition from felsic to mafic composition it is likely that the moon s extensive cratering history has continually overturned the original crust erasing any original systematic dependence of composition on depth or proximity to the mantle

low pressure crystallization of a volatile rich lunar basalt a means for producing local anorthosites the presence of anorthosite in the lunar highlands containing plagioclase that is compositionally less calcic than plagioclase in the ferroan anorthosites cannot be readily explained by the current lunar paradigm in which lunar anorthosite was produced as a floatation cumulate in the lunar magma ocean phase equilibrium experiments were conducted to investigate whether such anorthosite could arise locally from crystallization of aluminous magma at shallow levels within the lunar crust the experiments were conducted on a synthetic analog of cl f and s bearing aluminous highland basalt 14053 at pressures of approximately 1 bar and f o 2 at qif pyroxene and plagioclase an 93 89 saturation occurs early and with continued crystallization the residual liquid evolves to a silica poor halogen fe and ti rich melt with a computed density of 3 1 g ml this liquid remains higher in density than the plagioclase over the crystallization interval providing the possibility of plagioclase melt separation by liquid draining a model is proposed in which alkali anorthosite consisting of sodic anorthite or bytownite coupled with underlying pyroxenite or harzburgite is produced locally during crystallization of plagioclase from al rich magmas at or within roughly a kilometer of the lunar surface in this model segregation of plagioclase would be attained by settling of ferromagnesian minerals to the bottom of a shallow magma chamber and draining of low viscosity low silica fe ti k ree p enriched residual basaltic melt to deeper regions of the crust or into topographic lows such residual melt may be represented by magma compositions similar to some of the intermediate to high ti mare basalts this model would provide a mechanism that can account for the more alkali anorthosite identified in widespread isolated locales on the moon and allow for variable ages for such anorthosite that may extend to ages of the mare basalts

thermal infrared 2 5 13 5 μm spectroscopic remote sensing of igneous rock types on particulate planetary surfaces fundamental molecular vibration bands are significantly diminished by scattering thus such bands in spectra of fine particulate regoliths i e dominated by 5 m particles or regoliths displaying a similar scale of porosity are difficult to use for mineralogical or rock type identification consequently other spectral features have been sought that may be more useful in spectroscopic remote sensing of composition we find that mineralogical information is retained in overtones and combination tones of the fundamental molecular vibrations in the 3 0 to 7 0 m region but that relatively few minerals have a sufficiently distinctive band structure to be unambiguously identified with currently available techniques more significantly identification of general rock type as defined by the scfm chemical index scfm sio2 sio2 cao feo mgo is possible using spectral features associated with the principal christiansen frequency and with a region of relative transparency between the si o stretching and bending bands however environmental factors may affect the appearance and wavelengths of these features finally prominent absorption bands may result from the presence of relatively small amounts of water hydroxyl or carbonate because absorption bands exhibited by these materials in the 2 7 to 4 0 m region where silicate spectra are otherwise featureless increase strongly in spectral contrast with decreasing particle size such materials are thus detectable in very small amounts in a particulate regolith composed predominantly of silicate minerals

laboratory emissivity measurements of the plagioclase solid solution series under varying environmental conditions 1 new laboratory thermal infrared emissivity measurements of the plagioclase solid solution series over the 1700 400 cm 1 6 25 m spectral range are presented thermal infrared tir spectral changes for fine particulate samples 0 25 m are characterized for the first time under different laboratory environmental conditions ambient terrestrial like half vacuum mars like vacuum and vacuum with cooled chamber lunar like under all environmental conditions the christiansen feature cf is observed to vary in a systematic way with na rich end member albite having a cf position at the highest wave number shortest wavelength and the ca rich end member anorthite having a cf position with the lowest wave number longest wavelength as pressure decreases to 10 3 mbar four observations are made 1 the cf position shifts to higher wave numbers 2 the spectral contrast of the cf increases relative to the rb 3 the spectral contrast of the rb in the 1200 900 spectral range decreases while the spectral contrast of the rb in the 800 400 spectral range either increases or remains the same and 4 the tf disappears a relationship between the wavelength position of the cf measured under simulated lunar conditions and plagioclase composition an is developed although its exact form may evolve with additional data this linear relationship should be applied to current and future tir data sets of the moon our new spectral measurements demonstrate how sensitive thermal infrared emissivity spectra of plagioclase feldspars are to the environmental conditions under which they are measured and provide important constraints for interpreting current and future thermal infrared data sets

observations of hurricane hortense with two over the horizon radars hurricane hortense was observed in the atlantic ocean on 12 september 1996 by two high frequency over the horizon radars in texas and virginia looking at backscatter from the ocean surface dual radar coverage permits construction of an unambiguous surface wind direction field and a vector surface current field with about 15 km resolution in the storm s vicinity the known location of a storm band coincides with a region of surface convergence indicated by the radar the surface current field lags the wind field by about 3 h and shows the strongest ocean response to the right of the storm track with near inertial rotation in the storm s wake analysis of surface wave directionality shows that it depends on the recent wind direction history at each point

lro observations of morphology and surface roughness of volcanic cones and lobate lava flows in the marius hills 1 the volcanic domes cones sinuous rilles and pyroclastic deposits of the marius hills region of the moon 13 4 n 304 6 e represent a significant episode of magmatic activity at or near the lunar surface that is still poorly understood comparisons between lroc nac block populations mini rf data and diviner derived rock abundances confirm that blocky lava flows comprise the domes of the marius hills 8 m features measured by diviner indicate that the domes are not rich in silica and are not significantly different than surrounding mare materials lroc observations indicate that some of the dome building lava flows originated directly from volcanic cones many of the cones are c shaped while others are irregularly shaped and local topography and lava eruptions affect cone shape in general the cones are morphologically similar to terrestrial cinder and lava cones and are composed of varying amounts of cinder spatter and lava many of the cones are found in local groupings or alignments the wide range of volcanic features from broad low domes to steep cones represents a range of variable eruption conditions complex morphologies and variable layering show that eruption conditions were variable over the plateau

small area thorium features on the lunar surface 1 using an improved understanding of the lunar prospector gamma ray spectrometer lp grs spatial footprint we have derived a new map of global thorium abundances on the lunar surface this map has a full width half maximum spatial resolution of 80 km 2 and is mapped on the lunar surface using 0 5 0 5 pixels this map has allowed the identification and classification of 42 small area 3 g g in southwestern mare tranquillitatis near the apollo 11 landing site with our better understanding of the lp grs spatial footprint we have been able to constrain the surface thorium abundance at the compton belkovich thorium anomaly to 40 55 g g which is higher than any other measured location on the lunar surface and higher than most samples finally using 1 km pixel feo abundances from clementine and lp grs spatial footprint information we have been able to obtain plausible thorium distributions around kepler crater at a resolution of 1 km pixel the materials around kepler crater appear to be a relatively simple mixing of thorium rich mib compositions and high thorium mare basalts

analysis of lunar pyroclastic deposit feo abundances by lro diviner 1 thermal infrared reflectance spectra of rock forming minerals include a prominent minimum near 8 m known as the christiansen feature cf the inflection point wavelength is sensitive to the degree of polymerization of silicates which is strongly influenced by major cations notably iron in the minerals laboratory spectra of lunar soils demonstrate that the cf location is closely correlated to the sample s bulk feo abundance across the full range of apollo soil samples including pyroclastic glass this correlation is the basis for estimating lunar surface feo abundances using orbital thermal infrared measurements the diviner lunar radiometer experiment on the lunar reconnaissance orbiter includes three thermal infrared channels selected to determine the cf positions for sites across the lunar surface diviner measurements are used to derive feo abundances in the aristarchus sulpicius gallus and rima fresnel pyroclastic deposits the calculated feo abundances for aristarchus and sulpicius gallus lie within the compositional range of feo rich pyroclastic glasses but outside the range of most mare soils supporting the interpretations of these deposits as glass rich the calculated feo abundance for the rima fresnel deposit is close to that of mare soils supporting a contention that this deposit is dominated by basaltic fragments rather than glass the diviner measurements hold the potential to determine feo abundances in many lunar pyroclastic deposits a better understanding of these compositions will provide insight into the magmatic history and composition of the lunar interior as well as an enhanced inventory of potential resources for future human exploration

mineralogy at meridiani planum from the mini tes experiment on the opportunity rover the miniature thermal emission spectrometer mini tes on opportunity investigated the mineral abundances and compositions of outcrops rocks and soils at meridiani planum coarse crystalline hematite and olivine rich basaltic sands were observed as predicted from orbital tes spectroscopy outcrops of aqueous origin are composed of 15 to 35 by volume magnesium and calcium sulfates a high silica component modeled as a combination of glass feldspar and sheet silicates 20 to 30 and hematite only minor jarosite is identified in mini tes spectra mini tes spectra show only a hematite signature in the millimeter sized spherules basaltic materials have more plagioclase than pyroxene contain olivine and are similar in inferred mineral composition to basalt mapped from orbit bounce rock is dominated by clinopyroxene and is close in inferred mineral composition to the basaltic martian meteorites bright wind streak material matches global dust waterlain rocks covered by unaltered basaltic sands suggest a change from an aqueous environment to one dominated by physical weathering

mineral maps of the moon 1 global maps of the distribution of plagioclase orthopyroxene clinopyroxene and olivine on the moon were derived from radiative transfer analysis of 400 000 clementine uvvis spectra plagioclase inversely correlates with iron while clinopyroxene positively correlates with iron showing these are the major carriers of aluminum and iron respectively the distribution of olivine in the maria agrees with previous studies in the highlands the abundance of olivine is low but ubiquitous at a few percent except within the south pole aitken basin where it is only present in very small exposures in the very anorthositic farside highlands olivine is often the sole mafic mineral the abundance of orthopyroxene is generally low excepting elevated abundances in the nearside highlands and in areas near and within south pole aitken basin mare units with elevated abundances of orthopyroxene are found in some mare and cryptomare deposits distant from the sample return sites

global silicate mineralogy of the moon from the diviner lunar radiometer we obtained direct global measurements of the lunar surface using multispectral thermal emission mapping with the lunar reconnaissance orbiter diviner lunar radiometer experiment most lunar terrains have spectral signatures that are consistent with known lunar anorthosite and basalt compositions however the data have also revealed the presence of highly evolved silica rich lunar soils in kilometer scale and larger exposures expanded the compositional range of the anorthosites that dominate the lunar crust and shown that pristine lunar mantle is not exposed at the lunar surface at the kilometer scale together these observations provide compelling evidence that the moon is a complex body that has experienced a diverse set of igneous processes

the lunar reconnaissance orbiter mission six years of science and exploration at the moon abstract since entering lunar orbit on june 23 2009 the lunar reconnaissance orbiter lro has made comprehensive measurements of the moon and its environment the seven lro instruments use a variety of primarily remote sensing techniques to obtain a unique set of observations these measurements provide new information regarding the physical properties of the lunar surface the lunar environment and the location of volatiles and other resources scientific interpretation of these observations improves our understanding of the geologic history of the moon its current state and what its history can tell us about the evolution of the solar system scientific results from lro observations overturned existing paradigms and deepened our appreciation of the complex nature of our nearest neighbor this paper summarizes the capabilities measurements and some of the science and exploration results of the first six years of the lro mission

composition of the lunar highland crust from near infrared spectroscopy near infrared reflectance spectra of the lunar highlands are synthesized to obtain global information about the composition of the lunar near side crust immature exposed surfaces from small fresh craters mountains and massifs and large craters with central peaks are included in a survey of rock types across the lunar near side compositions recognized in these data include anorthosite noritic gabbric and troctolitic mineral assemblages three quarters of the areas studied that represent samples from the upper 1 2 km of lunar crust exhibit noritic compositions with different amounts of pyroxene and or brecciation alteration norites are ubiquitous across the near side and show no spatial clustering associated with any of the major basins in contrast to this noritic megaregolith of the upper crust material representing stratigraphically deeper zones 5 15 km of the lunar crust is dominated by gabbros anorthosites and troctolites with less than a quarter of the areas studied exhibiting a noritic composition the origin of the noritic megaregolith and its relation to deeper crustal material is thus somewhat of an enigma the current limited statistics for areas identified as anorthosites and troctolites are insufficient to derive global spatial distributions gabbroic areas however are notably concentrated in the western hemisphere although incomplete for a global assessment of crustal materials these data demonstrate that the lunar near side crust is clearly mineralogically heterogeneous both laterally and vertically and not well mixed below 1 2 km

nonmare volcanism on the moon photometric evidence for the presence of evolved silicic materials abstract images and photometric data from the lunar reconnaissance orbiter camera lroc narrow angle cameras nacs are used to investigate regions of the moon inferred from previous remote sensing compositional studies to be associated with nonmare silicic volcanics specifically lroc nac imagery with photometry normalized to account for local slopes using nac digital terrain models dtms was used to investigate the exposed areas associated with the compton belkovich volcanic complex cbvc hansteen alpha volcanic complex havc lassell massif lm gruithuisen domes gd and ejecta of aristarchus crater ac photometric studies of spacecraft landing sites for which ground truth compositional data exist allow us to study the relationship between photometric properties of soils and their mineralogical and chemical compositions the silicic regions have high reflectance and single scattering albedos that are consistent with different proportions of highly reflective minerals including alkali feldspar and quartz and low concentrations of mafic minerals of the silicic sites studied the cbvc has the highest reflectance values and single scattering albedos silicic pyroclastic deposits may also occur at the cbvc and we present evidence from laboratory spectra that an addition of up to 20 wt glassy silicic materials to a highlands type regolith simulant can account for the increased reflectance of these volcanic regions reflectance variations across and within the sites can be explained by mixing of felsic mineral components evolved to intermediate silicic compositions and or silicic pyroclastic deposits

iron distribution of the moon observed by the kaguya gamma ray spectrometer geological implications for the south pole aitken basin the orientale basin and the tycho crater abstract in this study we describe the distribution of iron on the moon as obtained by the kaguya high energy resolution gamma ray spectrometer kgrs we achieved for the first time the identification of iron based on the fast neutron flux obtained by the kgrs the iron distribution obtained by kgrs is compared to that of the lunar prospector gamma ray spectrometer lp grs showing that the feo distributions observed by kgrs and lp grs in general are in good agreement furthermore we compare the iron content data obtained by kgrs and lp grs to spectral reflectance measurements of the clementine kaguya and chandrayaan 1 spacecraft as well as those inferred from returned samples we found differences in feo concentration and distribution in areas of moderate abundance 6 15 wt of the south pole aitken basin mare orientale and around the crater tycho crater it implies that high concentrations of feo at mare ingenii in the south pole aitken basin and mare orientale are due to the presence of mare basalts whereas the enriched feo content in the central depression of the south pole aitken basin and the tycho crater indicates the presence of mafic materials such as impact melt breccia

the mons rumker volcanic complex of the moon a candidate landing site for the chang e 5 mission mons rumker is a large volcanic complex in oceanus procellarum on the moon and is a candidate landing site for china s chang e 5 sample return mission we conducted a comprehensive study of the topography geomorphology composition and stratigraphy of the mons rumker region with multi source remote sensing data in order to better understand the geology of the region and provide further support for the chang e 5 mission the results show that the rumker plateau stands 200 1300 m above the surrounding mare surface and 75 of the plateau has a slope of less than 3 at a baseline length of 30 m domes are the most prominent volcanic landforms in mons rumker and a total of 22 domes were identified and divided into two types that may represent different stages of volcanic activity spectral analyses indicated that mons rumker is covered by low ti basalt and the dominant mafic mineral is high calcium pyroxene though signs of mixing of highland materials and basalt have been found mons rumker has three main basalt units and their absolute model ages are 3 71 ga 3 58 ga and 3 51 ga respectively steep sided domes could be the youngest volcanic features on the plateau with indications that they were active until the eratosthenian a new geologic map of the study region was produced and used to interpret and discuss the geologic evolution of the region finally we propose two candidate landing sites for the chang e 5 mission