early diagenesis in deep sea turbidites the imprint of paleo oxidation zones sediment cores up to 35 m long have been recovered from turbidite sequences in the madiera abyssal plain and the southern nares abyssal plain detailed geochemical analyses of these sediments si al fe mn ca organic and inorganic carbon and associate pore waters nitrate ammonia silicate fe2 mn2 and alkalinity provide representative profiles of both steady state and nonsteady state diagenetic reactions initiated by oxidation and reduction processes models demonstrate that chemical transport in the pore water system is diffusion dominated over periods of a few thousands of years to several hundreds of thousands of years mn and fe mobilized in the subsurface mildly reducing sediments are precipitated as easily reducible oxyhydroxides in the near surface oxidized sediments nonsteady state profiles show the influence of episodic and rapid turbidite deposition and the imprint of oxidation zones that developed as the result of oxygen diffusion into the upper portions of turbidites during intervals of slow pelagic deposition the time required for development of oxidation zones between turbidites ranges from 2 0 to 15 ka in the madeira abyssal plain and from 0 2 to 2 4 ka in the southern nares abyssal plain paleo oxidation zones can be recognized in old turbidites by distinct changes in color between lower and upper portions of the deposit in the basal unoxidized portion of the turbidite the sediments are characteristically dark green gray or brown in the paleo oxidized zone the sediments are pale green blue or yellowish brown these zones in both the madeira and southern nares abyssal plains contain distinctly less organic c and carbonate in the paleo oxidized zone as compared with the unoxidized sediments depletion of carbonate content in the oxidized zones in the southern nares abyssal plain is particularly significant in that as much as 80 of the initial carbonates have been lost also the relative amounts of weak acid soluble fe and mn are generally less in the paleo oxidized zones due to the initial oxidation of metal carbonate and metal hydroxide forms to easily reducible oxide forms which are then subsequently solubilized under the mildly reducing conditions at depth in the sediment column

new views of lunar geoscience an introduction and overview beyond the earth the moon is the only planetary body for which we have samples from known locations the analysis of these samples gives us ground truth for numerous remote sensing studies of the physical and chemical properties of the moon and they are invaluable for our fundamental understanding of lunar origin and evolution prior to the return of the apollo 11 samples the moon was thought by many to be a primitive undifferentiated body e g urey 1966 a concept shattered by the data returned from the apollo and luna missions ever since new data have helped to address some of our questions but of course they also produced new questions in this chapter we provide a summary of knowledge about lunar geologic processes and we describe major scientific advancements of the last decade that are mainly related to the most recent lunar missions such as galileo clementine and lunar prospector 1 1 the moon in the planetary context compared to terrestrial planets the moon is unique in terms of its bulk density its size and its origin fig 1 1a c all of which have profound effects on its thermal evolution and the formation of a secondary crust fig 1 1d numerous planetary scientists considered the moon as an endmember among the planetary bodies in our solar system because its lithosphere has been relatively cool rigid and intact throughout most of geological time a one plate planet and its surface has not been affected by plate recycling an atmosphere water or life therefore the moon recorded and preserved evidence for geologic processes that were active over the last 4 4 5 b y and offers us the unique opportunity to look back into geologic times for which evidence on earth has long been erased fig 1 1c d impact cratering an exterior process is considered the most important surface process on the moon internal

global ocean extreme wave heights from spatial ensemble data abstracta novel approach to estimation of extreme value ocean significant wave height is investigated in which data from adjacent regions are pooled to form a spatial ensemble the equivalent dura

mapping of c4 plant input from north west africa into north east atlantic sediments abstract mapping the abundance of 13c in leaf wax components in surface sediments recovered from the seafloor off northwest africa 0 35 n reveals a clear pattern of 13c distribution indicating systematic changes in the proportions of terrestrial c3 and c4 plant input at 20 n latitude we find that isotopically enriched products characteristic of c4 plants account for more than 50 of the terrigenous inputs this signal extends westward beneath the path of the dust laden sahara air layer sal high c4 contributions apparently carried by january trade winds also extend far into the gulf of guinea similar distributions are obtained if summed pollen counts for the chenopodiaceae amaranthaceae and the poaceae are used as an independent c4 proxy we conclude that the specificity of the latitudinal distribution of vegetation in north west africa and the pathways of the wind systems trade winds and sal are responsible for the observed isotopic patterns observed in the surface sediments molecular isotopic maps on the marine sedimentary time horizons e g during the last glacial maximum are thus a robust tool for assessing the phytogeographic changes on the tropical and sub tropical continents which have important implications for the changes in climatic and atmospheric conditions

a case of post depositional aerobic degradation of terrestrial organic matter in turbidite deposits from the madeira abyssal plain abstract a set of oxidized and unoxidized sediment intervals from the f turbidite identified in two piston cores from the madeira abyssal plain map was analyzed for calcium carbonate total organic carbon toc total nitrogen tn stable carbon composition of toc 13c toc total hydrolyzable amino acids thaa total neutral sugars tsug lignin phenols lig two different lipid biomarkers of marine phytoplankton origin and vascular plantwax n alkanes and n acids comparison shows changes for all properties depicting the effect of post depositional aerobic oxidation the oxidation process re mineralized approximately 80 of the toc and approximately 60 of the tn in the original deposit and left the residual organic matter depleted in 13c by 1 7 2 9 thaa and tsug account for 10 or less of the toc in all samples leaving approximately 90 of the toc chemically unidentified thaa tsug lig marine phytoplankton biomarkers and plantwax n acids were lost from the oxidized deposit to an extent as great as that for toc two non protein amino acids alanine and aminobutyric acid and plant wax n alkanes displayed much less degradation 9 37 and concentrated 3 3 4 8 times relative to toc by the oxidation process these observations show that both marine and terrestrial components contribute to the re mineralized toc fraction a binary mixing approach was used to model quantitatively the change in 13c toc and plantwax n alkane concentration results suggest that terrestrial organic carbon contributes approximately 15 to the toc content of the original turbidite its abundance increases approximately 2 4 times as a consequence of the oxidation process and approximately 40 and 90 of the terrestrial and marine component of toc in the original turbidite respectively was destroyed by the oxidation process although selective preservation of terrestrial relative to marine organic carbon is a well documented phenomenon in sedimentary processes this study represents the first attempt to assess the sensitivity of terrestrial organic matter to oxidative degradation in a sedimentary environment

compositional and temporal investigation of exposed lunar basalts in the mare imbrium region abstract this paper presents an updated stratigraphical and compositional study of the exposed maria within the imbrium basin on the moon clementine multispectral data were employed to derive tio2 and feo wt abundance estimates of potentially distinct basaltic flows additionally nasa lunar orbiter images were used to estimate flow ages using crater count statistics mare imbrium shows evidence of a complex suite of low to high ti basaltic lava units infilling the basin over an 800 million year timescale more than a third 37 of identified mare basalts were found to contain 1 3 wt tio2 two other major mare lithological units representing about 25 of the surface each show tio2 values between 3 5 and 7 9 wt the dominant fraction 55 of the sampled maria contain feo between 16 and 18 wt followed by 27 of maria having 18 20 wt and the remaining 18 14 16 wt feo a crater frequency count for diameters 500 m shows that in three quarters of the sampled mare crater counts range between 3 5 and 5 5 10 2 per km2 which translates according to a lunar cratering model chronology into estimated emplacement ages between 3 3 and 2 5 ga a compositional convergence trend between the variations of iron and titanium oxides was identified in particular for materials with tio2 and feo content broadly above 5 and 17 wt respectively suggesting a related petrogenesis and evolution according to these findings three major periods of mare infill are exposed in the imbrium basin despite each period showing a range of basaltic compositions classified according to their tio2 content it is apparent that at least within these local geological settings the igneous petrogenesis generally evolved through time towards more tio2 and feo rich melts

the clementine mission to the moon scientific overview in the course of 71 days in lunar orbit from 19 february to 3 may 1994 the clementine spacecraft acquired just under two million digital images of the moon at visible and infrared wavelengths these data are enabling the global mapping of the rock types of the lunar crust and the first detailed investigation of the geology of the lunar polar regions and the lunar far side in addition laser ranging measurements provided the first view of the global topographic figure of the moon the topography of many ancient impact basins has been measured and a global map of the thickness of the lunar crust has been derived from the topography and gravity

understanding the lunar surface and space moon interactions the surface of the moon is a critical boundary that shapes our understanding of the moon as a whole all geologic mapping and remote sensing techniques utilize only the outermost portion of the moon before leaving the moon for study in our laboratories all lunar samples that have been studied existed at or very near the surface with the exception of the deeply probing geophysical techniques our understanding of the interior of the moon is derived from surficial but not superficial information coupled with boundary of the lunar crust it is the lower boundary layer of the tenuous lunar atmosphere and constitutes both a source and a sink for atmospheric gases the surface is also where the moon interacts with the space environment causing changes in the physical nature of lunar materials and provides a laboratory for the study of processes that occur on all airless bodies the data obtained remotely by the galileo clementine and lunar prospector missions as well as data derived from lunar meteorites have resulted in major changes to our understanding of global distributions of chemistry and rocks this chapter summarizes the current understanding of this critical interface the surface of the moon in its role as the lower boundary of the lunar atmosphere the upper boundary of the crust and the window through which we view through remote sensing the composition of the crust and the history of the moon in this post lunar prospector time the view of the moon has changed lending new perspectives to lunar samples and lunar processes but the new view will likely remain in flux as we continue to digest the results from these recent space missions and move forward to a new era of lunar exploration despite the freshness of our perspective this is an important moment to capture

radiative transfer modeling of the effect of mineralogy on some empirical methods for estimating iron concentration from multispectral imaging of the moon 1 several empirical models for deriving feo concentration from multispectral imaging of the moon are tested using model spectra of lunar soil the spectra are computed from a radiative transfer model based on the work of bruce hapke and cover the system plagioclase orthopyroxene clinopyroxene olivine ilmenite and vary the mg number and maturity over lunar relevant ranges the high degree of correlation between measured and spectrally estimated feo when applied to lunar soils returned by apollo provides constraints on the abundance of certain rock types and these constraints are consistent with geochemical mixing models good feo estimates are yielded for mixtures of plagioclase clinopyroxene and ilmenite by all the algorithms it is found that all spectral algorithms show large errors in the presence of significant olivine and significant errors in the presence of ferroan orthopyroxene the best performance is shown by the lemouelic et al 2002 algorithm that is also insensitive to topographic shading in the absence of ilmenite previously noted differences between spectrally derived feo and that derived by other techniques are all consistent with reported mineralogical differences

sedimentary organic matter preservation a test for selective degradation under oxic conditions the authors report here a test of the hypothesis that the extent of organic matter preservation in continental margin sediments is controlled by the average period accumulating particles reside in oxic porewater immediately beneath the water sediment interface oxygen penetration depths organic element compositions and mineral surface areas were determined for 16 sediment cores collected along an offshore transect across the washington continental shelf slope and adjacent cascadia basin individual amino acid sugar and pollen distributions were analyzed for a 11 to 12 cm horizon from each core and sup 14 c based sediment accumulation rates and stable carbon isotope compositions were determined from depth profiles within a subset of six cores from representative sites sediment accumulation rates decreased and dissolved o sub 2 penetration depths increased offshore along the sampling transect as a result oxygen exposure times oet increased seaward from decades mid shelf and upper slope to more than a thousand years outer cascadia basin organic contents and compositions were essentially constant within individual sediment cores but varied consistently with location in particular organic carbon surface area ratios decreased progressively offshore and with increasing oet three independent compositional parameters demonstrated that the remnant organic matter in farther offshore sediments is more degraded both concentrationmore and compositional patterns indicated that sedimentary organic matter exhibits a distinct and reproducible oxic effect oet helps integrate and explain organic matter preservation in accumulating continental margin sediments and hence provides a useful tool for assessing transfer of organic matter from the biosphere to the geosphere less

a mariner 10 color study of mercurian craters 1 we have used recalibrated mariner 10 color image data uv and orange to examine spectral trends associated with crater features on the incoming hemisphere of mercury spacecraft images of the moon galileo and clementine and lunar sample laboratory spectra provide a framework for interpreting the mercurian data two spectral parameter images were constructed one reveals opaque mineral abundance and the other provides a map of variations related to optical maturity and feo content the crater kuiper and its rays are bright mainly because they are fresh immature but also because kuiper has excavated material with a lower opaque content than the surroundings under the influence of space weathering kuiper will eventually lose its rays and evolve into a bright floored crater like lermontov lermontov and nearby smaller craters are examples of craters that are likely mature but remain bright because of the low opaque material exposed on their floors in this portion of the planet it appears that a surface layer with moderate opaque abundance overlies low opaque material found at depth on the basis of estimates of crater excavation depths we suggest that the moderate opaque surface layer is 3 4 km thick this two layer stratigraphy is reminiscent of the lunar highland crust and may have originated in similar magma ocean processes we also describe a feature that exposes dark material with a relatively high opaque content this feature could be a mercurian analog to a lunar dark halo impact crater or perhaps a pyroclastic deposit this implies that opaque rich possibly mafic magmas were generated in the interior and reached the surface through effusive or explosive activity

postdepositional oxic degradation of alkenones implications for the measurement of palaeo sea surface temperatures free and bound long chain alkenones c37 2 and c37 3 in oxidized and unoxidized sections of four organic matter rich pliocene and miocene madeira abyssal plain turbidites one from ocean drilling program site 951b and three from site 952a were analyzed to determine the effect of severe post depositional oxidation on the value of u37k the profiles of both alkenones across the redox boundary show a preferential degradation of the c37 3 compared to the c37 2 compound because of the high initial u37k values and the way of calculating the u37k this degradation hardly influences the u37k profiles however for lower u37k values measured selective degradation would increase u37k up to 0 17 units equivalent to 5 c for most of the u37k band width much smaller degradation already increases u37k beyond the analytical error 0 017 units consequently for interpreting the u37k record in terms of past sea surface temperatures selective degradation needs serious consideration

mineralogy of young lunar mare basalts assessment of temporal and spatial heterogeneity using m3 data from chandrayaan 1 abstract a comparative assessment of the mineralogy of young basalts 1 2 ga to 2 8 ga from the western nearside moscoviense basin and the orientale basin of the moon has been made using level 2 moon mineralogy mapper m3 data from the chandrayaan 1 mission spectral data characteristics of the individual units have been generated from fresh small craters to minimize the complications due to space weathering representative spectra for individual units and the derived spectral parameters band centers and integrated band depth ratio have been used to study composition of these young basalts a modified approach of gaffey et al gaffey m j cloutis e a kelley m s reed k l 2002 mineralogy of asteroids in asteroids iii the university of arizona press tucson pp 183 204 for olivine pyroxene mixtures and the methodology of adams adams j b 1974 j geophys res 79 4829 4836 http dx doi org 10 1029 jb079i032p04829 for interpreting pyroxene type have been used to improve our understanding of the spectral behavior of these basalts most of the young basalts of oceanus procellarum are characterized by abundant olivines and they show complex volcanic history vast exposures of olivine concentrated units having higher abundance of olivine content than high ca pyroxenes are emplaced in the northern oceanus procellarum region mostly they show distinct stratigraphic gradation with the immediately underlying units of relatively lower olivine content the moscoviense unit shows signatures of fe rich glasses along with clinopyroxenes the basalts of orientale basin are typically devoid of olivine and are rich in high ca pyroxene thus mineralogy of these mare basalts which erupted during the late stage volcanism vary across the moon s surface however broader observations reveal apparently higher feo content in the younger basalts of western nearside and orientale region

global occurrence trend of high ca pyroxene on lunar highlands and its implications we present details of the global distribution of high ca pyroxene hcp rich sites in the lunar highlands based on the global data set of hyperspectral reflectance obtained by the selene spectral profiler most hcp rich sites in the lunar highlands are found at fresh impact craters in each crater most of the detection points are distributed on the ejecta rim and floor of the impact craters rather than the central peaks while the central peaks are dominated by purest anorthosite pan this indicates that hcp rich materials originate from relatively shallower regions of the lunar crust than pan in addition while all ray craters with sizes larger than 40 km possess hcp rich materials small fresh craters with sizes less than 6 10 km do not indicating that the uppermost mixing layers in the lunar crust are not dominated by hcp based on these results we propose that in the upper lunar crust a hcp rich zone overlying the pan layer exists below the uppermost mixing layer this hcp rich zone may originate from interstitial melt during the formation of the flotation anorthositic cumulate while an impact ejecta origin impact melt origin and or magmatic intrusion into the upper lunar crust may also account for the occurrence of hcp rich sites in the highlands

the constitution and structure of the lunar interior the current state of understanding of the lunar interior is the sum of nearly four decades of work and a range of exploration programs spanning that same time period missions of the 1960s including the rangers surveyors and lunar orbiters as well as earth based telescopic studies laid the groundwork for the apollo program and provided a basic understanding of the surface its stratigraphy and chronology through a combination of remote sensing surface exploration and sample return the apollo missions provided a general picture of the lunar interior and spawned the concept of the lunar magma ocean in particular the discovery of anorthite clasts in the returned samples led to the view that a large portion of the moon was initially molten and that crystallization of this magma ocean gave rise to mafic cumulates that make up the mantle and plagioclase flotation cumulates that make up the crust smith et al 1970 wood et al 1970 this model is now generally accepted and is the framework that unifies our knowledge of the structure and composition of the moon the intention of this chapter is to review the major advances that have been made over the past decade regarding the constitution of the moon s interior much of this new knowledge is a direct result of data acquired from the successful clementine and lunar prospector missions as well as the analysis of new lunar meteorites as will be seen results from these studies have led to many fundamental amendments to the magma ocean model much of what we know from sample analyses has been previously summarized elsewhere and only their most important aspects will be discussed in this chapter the reader is referred to the relevant chapters in the books basaltic volcanism on the terrestrial planets basaltic volcanism study project 1981 the

elemental and major biochemical changes across an oxidation front in a relict turbidite an oxygen effect abstract the elemental and major biochemical compositions of the relict f turbidite sampled in two cores from the madeira abyssal plain were determined this fine grained distal sequence occurs at ca 9 m core depth and includes a surficial oxidized horizon defined by a distinct color change oxygen diffused downward through sediments above this interface and in ca 10 kyr destroyed 80 of the organic substances that below the front had survived degradation in the presence of porewater sulfate for ca 140 kyr these deposits provide an opportunity to establish the extent and selectivity of oxic sedimentary degradation under natural conditions without the usual complications of bioturbation and varying sources or sedimentation rates in both cores a sample from the upper oxidized layer was compared to two samples from the underlying unoxidized layers the unoxidized sequences of both turbidities contained 0 93 1 02 wt organic carbon oc and 0 10 0 11 wt total nitrogen tn approximately 20 of the initial oc and 40 of the initial tn remained in the oxidized horizons with a consequent decrease in atomic c n ratio from ca 11 to ca 5 all samples gave very low yields of lignin phenols and comparable oc normalized yields of total aldoses and amino acids and indicated predominantly marine organic matter om and nonselective oxic degradation of these biochemical classes compositions of individual aldoses and amino acids generally were also similar in surface and deep sediments except that the oxidized horizons yielded markedly elevated 3 5x percentages of nonprotein amino acids this study clearly demonstrates that prolonged exposure to oz can lead to organic matter alteration which is far more extensive than that obtained with sulfate alone in comparison to early diagenesis however alteration of the measured biochemicals was largely nonselective such oxidation reactions could control the distribution and composition of organic matter in slowly accumulating continental rise and deep ocean environments

modifications of the c37 alkenone and alkenoate composition in the water column and sediment possible implications for sea surface temperature estimates in paleoceanography 1 the literature pertaining to c37 alkenone and c37 and c38 alkenoate production and diagenesis has been reviewed and evaluated for issues that might jeopardize their usefulness in paleotemperature estimation we also examined the use of the c37 alkenones as paleoproductivity indicators the stability of their 13c isotopic compositions and their incorporation into the nonsolvent extractable organic matter fraction biological transformation of organic matter by bacteria and zooplankton does not appear to cause significant changes to the ratio of c37 2 and c37 3 alkenones but there are major alterations in the relative composition of alkenoates studies of water column processes and postdepositional sedimentary changes indicate overall stability in the c37 2 c37 2 c37 3 ratio leading to effective preservation of the paleotemperature signal this is not the case for alkenoates and there also appear to be some doubts about the dependence between sea surface temperature and the sedimentary abundance of the c37 4 alkenone c37 alkenones may provide useful qualitative estimates of marine paleoproductivity although these compounds are apparently only derived from haptophycea changes in their quantitative composition might reflect changes in nutrient availability that on sedimentary timescales should also be generally significant of other algal species one caveat is that in highly productive upwelling systems productivity may be expressed mostly in diatom growth and thus not measurable by the c37 alkenones no changes in 13c c37 alkenone composition are observed upon zooplankton ingestion although this is expected from a theoretical perspective further studies are encouraged in order to fully assess the stability of the isotopic signal during c37 alkenone diagenesis finally alkenones bound in the nonextractable fraction of sedimentary organics have not been adequately studied and further work is required to clarify any possible correspondence with a temperature signal

selective organic matter preservation in burn down turbidites on the madeira abyssal plain 1 oxidized intervals of five organic rich madeira abyssal plain map turbidites deposited during the miocene pliocene and pleistocene all displayed comparable major loss of total organic carbon toc 84 3 1 accompanied by a negative isotopic 13c shift ranging from 0 3 to 2 9 major but significantly lower loss of total nitrogen ntot 61 7 1 also occurred leading to a decrease in toc relative to ntot c ntot and a 1 3 to 2 7 ntot isotopic 15n shift compound specific isotopic measurements on plant wax n alkanes indicate the terrestrial organic component in the unoxidized deposits is 13c enriched owing to significant c4 contribution selective preservation of terrestrial relative to marine organic carbon could account for the 13c behavior of toc upon oxidation but only if a 13c depleted component of the bulk terrestrial signal is selectively preserved in the process although the c ntot decrease and positive 15n shift seems inconsistent with selective terrestrial organic preservation results from analysis of a modern eolian dust sample collected in the vicinity indicate these observations are compatible regardless of the specific explanation for these isotopic observations however our findings provide evidence that paleoreconstruction of properties such as pco2 using the 13c of toc is a goal fraught with uncertainty whether or not the marine sedimentary record considered is contaminated with significant terrestrial input nonetheless despite major and selective loss of both marine and terrestrial components as a consequence of postdepositional oxidation intensive organic geochemical proxies such as the alkenone unsaturation index u37k appear resistant to change and thereby retain their paleoceanographic promise

the titanium contents of lunar mare basalts lunar mare basalt sample data suggest that there is a bimodal distribution of tio2 concentrations using a refined technique for remote determination of tio2 we find that the maria actually vary continuously from low to high values the reason for the discrepancy is that the nine lunar sample return missions were not situated near intermediate basalt regions moreover maria with 2 4 wt tio2 are most abundant and abundance decreases with increasing tio2 maria surfaces with tio2 5 wt constitute only 20 of the maria although impact mixing of basalts with differing ti concentrations may smear out the distribution and decrease the abundance of high ti basalts the distribution of basalt ti contents probably reflects both the relative abundances of ilmenite free and ilmenite bearing mantle sources this distribution is consistent with models of the formation of mare source regions as cumulates from the lunar magma ocean

chemical information content of lunar thermal and epithermal neutrons simulations of equilibrium thermal and epithermal neutron flux spectra for the moon have been studied to determine their chemical information content most of this information resides in a single parameter the ratio of macroscopic absorption to energy loss cross sections although this parameter cannot specify the chemistry of lunar soils uniquely it provides an index that can be used to quantitatively separate anorthositic from mafic chemistries hydrogen abundances can best be derived from measurements of the epithermal neutron flux which is strongly related to its macroscopic energy loss cross section the ratio of thermal to epithermal neutron flux measured by lunar prospector is shown to agree quantitatively with simulations this agreement is used to show that the highlands terrane on the farside of the moon is anorthositic containing high percentages of plagioclase and possibly a range of mg suite minerals with a high mg mg fe atomic ratio our best estimate of the abundance of feo is 2 with an upper limit of 5

the origin and evolution of lunar high ti basalts periodic melting of a single source at mare tranquillitatis abstract five groups of basalts a b1 b2 b3 d with three principal ages exist at the apollo 11 site these range from the low k low rare earth element ree groups b1 b2 and b3 to the low k high ree group d basalts to the high k high ree group a basalts the group a basalts are the only high k 0 2 wt k2o basalts and youngest with an age of 3 59 02 ga groups b3 and b1 are 3 71 02 and 3 67 02 ga respectively group b2 basalts are the oldest at 3 85 02 ga group d basalts have not been dated fractionation modelling for major and trace elements indicates that the b1 basalts could have formed from a b3 like parent liquid the b2 and d basalts can also be related to liquids similar to the b3 b1 composition through the presence of varying amounts of modal whitlockite thus the entirety of low k high ti basalts at apollo 11 may have formed through melting of the same source region the group a basalt compositions are consistent with formation from a different parent liquid with the composition of apollo 11 orange glass modelling of major and trace elements in the apollo 11 orange glass indicate that the composition of the group a basalts is consistent with fractionation of this glass coupled with some assimilation 7 5 15 of an evolved kreep like material however this component is much younger than primitive kreep 4 4 ga this neukreep component similar to the composition of quartz monzodiorites described from the apollo 15 site probably represents evolved material formed during plutonism prior to the formation of the apollo 11 orange glass liquid

testing the relation between uv vis color and tio2 content of the lunar maria reflectance spectroscopy is important for placing lunar samples into a regional and global geologic context to this end the ultraviolet visible uv vis color ratio used to estimate the tio2 composition of mature mare basalts has been one of the most widely used spectral parameters in lunar exploration we examine the correlation between uv vis color and tio2 content using a combination of clementine lunar prospector and sample data to document the extent to which color is dependent upon tio2 examination of the remotely sensed data reveals that the correlation between uv vis ratio and tio2 composition is best represented by a sigmoidal trend rather than the canonical linear or curvilinear correlation with this information we are then able to evaluate between two models that propose different explanations for the relationship between uv vis color and tio2 the first model attributes the correlation between tio2 and uv vis color to spectrally neutral opaques i e ilmenite while the other emphasizes the effect of fe ti charge transfer in lunar glasses and dual scattering mechanisms between high and low ti basalts we do not find evidence in the spectral data to support the occurrence of fe ti charge transfer in lunar glass as the principal cause for color in high ti basalts the data also do not substantiate the existence of different scattering mechanisms e g volume v surface scattering between high and low tio2 basalts instead our analyses substantiate that the spectral effects of ilmenite exhibit a major influence over the uv vis ratio by including sample data we find that in addition to ilemenite tio2 content factors such as feo content ilmenite grain size modal abundance of plagioclase and the olivine to pyroxene ratio in a mare soils can influence the uv vis continuum these findings point to promising avenues of research that future uv vis spectral techniques can exploit in order to yield more accurate tio2 estimates and potentially additional petrologic information

the thickness and volume of young basalts within mare imbrium basaltic volcanism is one of the most important geologic processes of the moon research on the thickness and volume of late stage basalts of mare imbrium helps better understand the source of lunar volcanism and eruption styles based on whether apparent flow fronts exist or not the late stage basalts within mare imbrium were divided into two groups namely upper eratosthenian basalts uem and lower eratosthenian basalts lem employing the topographic profile analysis method for uem and the crater excavation technique for lem we studied the thickness and distribution of eratosthenian basalts in mare imbrium for the uem units their thicknesses were estimated to be similar to 16 34 2 m with several layers of individual lava similar to 8 13m inside the estimated thickness of lem units was similar to 14 45 1 m with a trend of reducing thickness from north to south the measured thickness of late stage basalts around the chang e 3 landing site similar to 371m was quite close to the results acquired by the lunar penetrating radar carried on board the yutu rover similar to 35m the total volume of the late stage basalts in mare imbrium was calculated to be similar to 8 671 320 km 3 which is 4 times lower than that of schaber s estimation similar to 4x10 4 km 3 our results indicate that the actual volume is much lower than previous estimates of the final stage of the late basaltic eruption of mare imbrium together the area flux and transport distance of the lava flows gradually decreased with time these results suggest that late stage volcanic evolution of the moon might be revised plain language summary the late stage younger than 3 1ga volcanism of the moon deposited large areas of basalts in mare imbrium and oceanus procellarum these basalts have different colors dark and blue compared to old basalts sampled by apollo and luna missions in order to understand how these young basalts erupted in mare imbrium we estimated their thickness and volume using multiple data using detailed visible and near infrared spectral data in combination with topographic information we estimated the height of lava flows and the thickness of late stage rocks excavated by impact craters our results indicate that these young basalts have a thickness of tens of meters and a total volume of similar to 8 671 320 km 3 both values are smaller than those of previous estimates suggesting a smaller volcanic activity than previously thought these results indicate that the magmatic activity gradually weakened in this region

lunar soil characterization consortium analyses pyroxene and maturity estimates derived from clementine image data abstract the mineralogy of a planetary surface is a diagnostic product of its formation and geologic evolution global assessment of lunar mineralogy at high spatial resolution has been a long standing goal of lunar exploration currently the only global data available for such study is multispectral imagery from the clementine mission we use the detailed compositional petrographic and spectroscopic data of lunar soils produced by the lunar soil characterization consortium to explore the use of multispectral imaging as a diagnostic tool we compare several statistically optimized formulations of links between spectral and mineral parameters and apply them to clementine uv vis data the most reliable results are for estimations of pyroxene abundance and maturity parameters agglutinate abundance i s feo estimations of different pyroxene composition low ca versus high ca appear good in a relative sense but absolute values are limited by residual wavelength dependent clementine photometric calibrations since the signal to noise of clementine multispectral data is good at the 1 km scale almost any combination of parameters that capture inherent spectral variance can provide spatially coherent maps although the parameters may not actually be directly related to composition clementine estimates are useful for identifying scientific or exploration targets for imaging spectrometer sensors of the next generation that are specifically designed to characterize mineralogy

mineralogy of the last lunar basalts results from clementine the last major phase of lunar volcanism produced extensive high titanium mare deposits on the western nearside which remain unsampled by landing missions the visible and near infrared reflectance properties of these basalts are examined using clementine multispectral images to better constrain their mineralogy a much stronger 1 m ferrous absorption was observed for the western high titanium basalts than within earlier maria suggesting that these last major mare eruptions also may have been the most iron rich these western basalts also have a distinctly long wavelength 1 m ferrous absorption which was found to be similar for both surface soils and materials excavated from depth supporting the interpretation of abundant olivine within these deposits spectral variation along flows within the imbrium basin also suggests variations in ilmenite content along previously mapped lava flows as well as increasing olivine content within subsequent eruptions

the regolith properties of the chang e 5 landing region and the ground drilling experiments using lunar regolith simulants abstract the chang e 5 ce 5 mission is china s first lunar sample return mission the rumker region in northern oceanus procellarum was selected as the landing area ce 5 will automatically sample 2 kg of lunar samples from the surface and subsurface previous studies focused more on the geological background of the landing region however the lunar regolith properties also have a significant influence on the mission especially drilling and thus should be studied and constrained in this research we analyzed the lunar regolith properties of the ce 5 landing region first using remote sensing measurements the western maria and eastern maria in the landing region are both covered by very low ti to low ti basaltic regolith the western mare regolith with longer exposure to space weathering is more mature finer and thicker than the eastern mare regolith cug series lunar regolith simulants were then produced based on our analysis physically and chemically of the regolith properties of ce 5 landing region and compared to apollo soils finally the lunar simulants were used to perform ground drilling experiments to support the drilling of the ce 5 mission in a fixed rotation speed 120 rpm feed speed 120 mm min and total drilling depth 1 m 274 291 and 346 g of lunar simulants were cored on simulants mixture 1 mixture 2 and mixture 3 respectively our experiments suggest that it is easier to drill and core finer and looser lunar regolith in this case the western mare regolith is easier for drilling than the eastern mare regolith however samples from the eastern young maria em3 em4 are scientifically more meaningful we propose that landing on and drilling in a smooth and mature area in unit em4 should be the highest priority for the ce 5 mission this can be accomplished by careful landing site selection precise landing and optimized drilling control

stratigraphy and composition of lava flows in mare nubium and mare cognitum three major periods of basaltic activity characterize the infill of the basins each of these periods was itself punctuated by discrete phases of widespread magma eruptions three during both the late imbrian epoch and the early eratosthenian period and then two in the late eratosthenian period we found the youngest lavas off the eastern border of the fra mauro peninsula and mantling a much larger area over most of the central western nubium basin our results place the nubium cognitum basalts in the low ti category 1 5 wt tio2 the data indicate that the majority 90 of the mare terrain has iron content between 18 and 22 wt in particular feo contents tend to concentrate toward two compositional poles each of 20 wt and a much smaller one of 15 wt these values are typical of nearside lunar maria to complement our compositional data we present a census of craters larger than 500 m using orbiter iv images the result was a crater count average with frequency 5 6 10 2 km 2 translating into an inferred mean age of 3300 ma for the exposed lava flows by combining lava chemistry with age we find a possible correlation between the ages of the most prominent flow units and their estimated titanium content with younger basalts becoming progressively ti richer with time from 2 3 to 4 5 wt tio2

late stage imbrium volcanism on the moon evidence for two source regions and implications for the thermal history of mare imbrium abstract large open fissures or volcanic rifts can form in volcanic terrain and they are also conduits for magma ascending through the lunar crust on the moon we investigated two volcanic source regions within mare imbrium by tracking surface morphologic features and compositional information the euler source region is situated at the southwest edge of the basin while the lambert source region lies off the south margin of the imbrium mascon survey of dike surface manifestations in euler source site suggest that dikes are the possible source of the local upper basaltic flows and the last lava phases with well developed scarps near the euler crater which extend northeast to the basin center the euler dike swarm are radial to the basin and reveal possible dike to conduit transition mechanism they reveal radial subsurface fractures which may be tensional cracks preceding to the emplacement of the last stage of the mare fill of these the largest dike has a more than 100 km length the spatial arrangement of tectonic and volcanic features in lambert source site is directly or indirectly controlled by the regional compression and extension stresses associated with flexure in response to mascon and basalt loading in addition compositional variation trends show a general southwest to northeast flooding direction of the exposed high ti basalts this will have important implications for both the imbrium basin s mare volcanism and for the thermal evolution of mare imbrium and the moon

mapping the feo and tio2 content of the lunar surface with multispectral imagery the derivation of quantitative elemental concentrations from multispectral imaging of the moon has long been a goal of lunar remote sensing concentration maps at the spatial resolutions available from the recent clementine mission would provide a revolutionary new tool for understanding the origin and evolution of the lunar crust lucey et al 1995 presented a method for extracting the concentration of fe from multispectral imaging of the moon this paper examines and quantifies important aspects ofthat technique left unexamined by lucey et al which had the potential to severely limit its utility these aspects include the effects of maturity grain size mineralogy shading due to topography and the presence of glass we also present a new algorithm for derivation of tio2 from multispectral imaging of both mare and highland units we find that both techniques are only weakly sensitive to maturity and that they have about 1 wt accuracy based on examination of the spectral properties and compositions of resolved lunar sampling stations presented by blewett et al 1997 we also discuss these findings in the context of two contrasting views of the effect of composition on lunar spectral properties presented by pieters and coworkers and hapke and coworkers we find the view of hapke and coworkers to be more consistent with our observations using a global mosaic of clementine multispectral data and these element derivation algorithms we find that the global modal abundance of feo is 4 5 wt 1 wt and the global modal abundance of tio2 is 0 45 wt 1 wt

global elemental maps of the moon the lunar prospector gamma ray spectrometer lunar prospector gamma ray spectrometer spectra along with counting rate maps of thorium potassium and iron delineate large compositional variations over the lunar surface thorium and potassium are highly concentrated in and around the nearside western maria and less so in the south pole aitken basin counting rate maps of iron gamma rays show a surface iron distribution that is in general agreement with other measurements from clementine and the lunar prospector neutron detectors

moon near infrared spectral reflectance a first good look a positive identification of the minerals olivine plagioclase and several types of pyroxenes were made at several locations on the lunar surface by using remote measurements for example the crater aristarchus is found to have an average pyroxene composition of augite and plagioclase is obviously present a dark mantle deposit in the crater j herschel is at least partly composed of a mixture of 70o7o olivine and 30o7o pyroxene these determinations were possible because the reflectance spectra for 10 20 km diameter lunar areas have been measured for the first time in the ir spectral region 0 65 2 5 m with sufficient spectral resolution and photometric precision to define mineral electronic absorption bands the reflectance for all lunar regions observed over 100 to present continues to increase toward longer wavelengths to at least 2 5 m and several mineral absorption bands appear the telescopic spectra are of similar quality and contain features similar to laboratory spectra of lunar samples the absorption features in several spectra have been quantitatively analyzed using newly developed computer processing techniques including thermal flux removal and absorption band fitting to produce these mineral identifications detection and quantitative analysis of these absorptions provide a much improved basis for remotely determining and mapping surface mineralogy quantitatively from the ground or using airborne or spacecraft platforms

lipid biomarker fluxes in the arabian sea with a comparison to the equatorial pacific ocean abstract fluxes and distributions of organic carbon oc and lipid biomarkers were measured in the western arabian sea as a function of season depth and distance from the coast of oman during the us jgofs arabian sea process study in 1994 1995 a strong seasonal pattern in oc and lipid flux is related to the annual monsoon cycle in the western arabian sea with the highest fluxes measured during the southwest monsoon fluxes were greatly attenuated with depth in the water column and in surface sediments as remineralization effectively consumed particulate organic matter a comparison of water column fluxes with oc and lipid accumulation rates in sediments confirms that the water sediment interface is a hot spot for organic matter degradation biomarker compositions also varied seasonally and with distance offshore reflecting seasonal and spatial succession of their biological sources and their subsequent export through the water column degradation of oc and biomarkers was extremely efficient with only a tiny fraction

constraints on volatile concentrations of pre eruptive lunar magma abstract until recently the moon had long been thought to be depleted of volatiles such as h 2 o s co x and cl 2 researchers have recently measured volatile concentrations in the minerals glasses and inclusions of lunar samples and the results show that lunar rocks contain volatiles that are more similar to terrestrial materials than was previously thought mare basalts are located on the earth facing hemisphere in large impact basins and they are not representative of the feldspathic highlands thus it is likely that the density of lunar mafic magma exceeds that of the highland rocks based on buoyancy alone according to this observational fact we calculate the density of mare basalt to give a constraint for the maximum amount of water mare basalt can contain because water can effectively decrease the density of mare magma our result shows that water contained in the pre eruptive magma could not have been more than 1000 ppm otherwise the density of very low ti basaltic magma would be less than that of the highland rocks additionally if magma contains other species of volatiles such as c o s f or cl 2 the water in the pre eruptive magma would have to be much less than 1000 ppm because volatiles such as co 2 can effectively decrease the solubility of water in silicate melts based on these calculations on densities and a comparison with water in morb we conclude that the moon s water is not as great as has been recently suggested

northern imbrium noritic anomaly 1 an analysis of the northern imbrium noritic nin region was conducted using clementine uvvis multispectral images and derived band parameters band parameters were used to map spatial variations in composition and to aid in general separation of compositional signatures from effects such as maturity and topography compositional trends in which the abundance of mafic materials relative to feldspathic materials increased were observed with depth in large craters with distance to the west and with distance from the center of the imbrium basin on average the region appears to have an anomalously mafic surface composition with a noritic upper unit overlying and grading into a more feldspathic layer that is exposed in the central peak of the largest crater in the region of several hypotheses that could explain these results we favor a scenario in which feldspathic crustal materials underlie moderately mafic south pole aitken antipodal ejecta which is covered by and mixed with mafic imbrium ejecta limitations of the clementine uvvis data preclude quantitative evaluation of these hypotheses but compositional information from new high resolution data sets should allow the direct comparisons needed to test these hypotheses

diploptene an indicator of terrigenous organic carbon in washington coastal sediments the pentacyclic triterpene 17 beta h 21 beta h hop 22 29 ene diploptene occurs in sediments throughout the columbia river drainage basin and off the southern coast of washington state in concentrations comparable to long chain plantwax n alkanes the same relationship is evident for diploptene and long chain n alkanes in soils from the willamette valley microorganisms indigenous to soils and soil erosion are indicated as the biological source and physical process respectively for diploptene in coastal sediments similarity between the stable carbon isotopic composition delta 13cpdb of diploptene isolated from soil in the willamette valley 31 2 0 3 and from sediments deposited throughout the washington coastal environment 31 2 0 5 supports this argument values of delta for diploptene in river sediments are variable and 8 17 lighter indicating that an additional biological source such as methane oxidizing bacteria makes a significant contribution to the diploptene record in river sediments selective biodegradation resulting from a difference in the physicochemical association within eroded particles can explain the absence of the more 13c depleted form of diploptene in washington coastal sediments but this mechanism remains unproven

lunar mare basalts in the aristarchus region implications for the stratigraphic sequence from clementine uvvis data the aristarchus region of oceanus procellarum is an area concentrated with lunar basalts which were mainly produced by the last major phase of lunar volcanism on the western nearside a group of lunar sample and remote sensing scientists have carried out the extensive task of characterization of lunar mare soils with regard to their mineralogical and chemical makeup and regional geologic mapping spectral parameters of the high spatial resolution clementine images are used to identify and define these basalts as different compositional and spectral units this endeavor is aimed at deciphering the subtle spectral characteristics of mare soils and validating the mapping technique used in this study together with making statistical analysis of the links between the basalt types with ages in order to provide a further understanding of material types and geologic evolution in the aristarchus region of the moon from the new perspective of mining geologic information in multivariable image spaces spectrally distinct 9 high ti and 11 low ti basalt reference spectra have been distinguished and as a result more than 70 spectrally and compositionally basaltic units which range in age from 1 20 b y to 3 74 b y have been identified to some extent a potential relationship between composition and relative age exists in the statistical analysis of the links between spectral types related with the clementine ratio colors of various basalts and ages in this study which suggests that composition with different states of maturity correlate with age to some extent the mineralogical characteristics and spectra age relationship in the marius hills region indicate that the early basalts may still be exposed at the surface deposit after prolonged volcanic activity in this region this may be a result of not being blanketed by later lava flows or lava extrusions of underlying low ti basalts in addition stratigraphic analysis also reveals and confirms that tio 2 concentrations appear to vary independently with time and generally eruptions of

the influence of oxic degradation on the sedimentary biomarker record i evidence from madeira abyssal plain turbidites free and ester bound lipid biomarkers were analysed in oxidised and unoxidised parts of four distinct turbidites from the madeira abyssal plain map which contained 1 to 2 organic carbon homogeneously distributed throughout the turbidites at the time they were deposited these turbidites are well suited to study the effects of oxic degradation on lipid biomarkers without the complicating influence of varying organic matter sources sedimentation rates or bioturbation one sample from the oxidised turbidite was compared with two samples from the unoxidised part of each turbidite postdepositional oxic degradation decreased concentrations of biomarkers by several orders of magnitude the ester bound lipids were degraded to a far lesser extent than their free counterparts were the extent of degradation of different compounds differed substantially within a specific class of biomarkers degradation also took place to a different extent altering their distributions this study shows that oxic degradation of the organic matter may have a profound effect on the biomarker fingerprint and may result in a severe bias in for example the interpretation of organic matter sources and the estimation of the palaeoproductivity of specific groups of phytoplankton

in situ optical measurements of chang e 3 landing site in mare imbrium 1 mineral abundances inferred from spectral reflectance the visible and near infrared imaging spectrometer on board the yutu rover of chinese chang e 3 mission measured the lunar surface reflectance at a close distance similar to 1m and collected four spectra at four different sites these in situ lunar spectra have revealed less mature features than that measured remotely by spaceborne sensors such as the moon mineralogy mapper instrument on board the chandrayaan 1 mission and the spectral profiler on board the kaguya over the same region mineral composition analysis using a spectral lookup table populated with a radiative transfer mixing model has shown that the regolith at the landing site contains high abundance of olivine themineral abundance results are consistent with that inferred from the compound measurement made by the on board alpha particle x ray spectrometer

refined estimation of marine and terrigenous contributions to sedimentary organic carbon molecular carbon isotopic 13c 12c ratios of a selected marine organic biomarker compound a c37 alkadienone from the pigmy basin deep sea drilling program hole 619 in the northern gulf of mexico varied by 5 3 in sychrony with the last 100 ka glacial interglacial cycle this carbon isotopic 13c variation is likely due to the effect of climatically linked variations in concentrations of co2 aq on photosynthetic fractionation of carbon isotopes by phytoplankton measurement of the 13c of the alkadienone 37 2 to reconstruct the carbon isotopic composition of total marine organic carbon permits improved estimates of the time varying 13c of preserved marine organic carbon end members with the time series record of marine end members the concentrations and net accumulation rates of terrigenous corg and marine corg are calculated and their paleoceanographic significance is considered although this method may be improved by consideration of additional biomarkers representative of diverse marine and terrigenous inputs it is the first application of molecular isotopic analysis to quantifying marine and terrigenous corg concentrations further application of such techniques will be become valuable in reconstructing regional and global budgets of marine and terrigenous corg accumulation

beginning and end of lunar mare volcanism mare volcanism on the moon is commonly attributed to an important but relatively short lived epoch of internal heating after 3 900 myr bp but before about 2 500 myr bp refs 1 2 although some studies suggested that mare volcanism had started earlier3 5 than times indicated by dated lunar samples only recently have photogeological spectral and geochemical data6 8 documented the importance of a pre 4 000 myr bp epoch similarly early earth based geological mapping revealed a bright rayed crater lichtenberg superposed by mare units9 thereby indicating that mare volcanism must have extended to times significantly more recent than 3 100 myr bp lunar orbital photography confirmed this inferred strati graphical relationship10 but crater statistics indicated that the youngest units were at least twice the age of copernicus or between 1 700 and 2 000 myr bp refs 11 13 we present here the inferred distribution and style of the early phases of mare volcanism based on current evidence and conclude that certain regions of the moon underwent two distinct pulses of igneous activity we then examine crater statistics for the post lichtenberg mare unit and other selected units and conclude that mare volcanism extended to a time comparable with that of the copernicus impact or 1 myr bp these reassessments of the oldest and youngest maria provide new constraints on geophysical models of the internal thermal history of the moon

compositional analyses of lunar pyroclastic deposits abstract the 5 band clementine uvvis data at 100 m pixel were used to examine the compositions of 75 large and small lunar pyroclastic deposits lpds and these were compared to representative lunar maria and highlands deposits results show that the albedo spectral color and inferred composition of most lpds are similar to those of low titanium mature lunar maria these lpds may have consisted largely of fragmented basalt with substantial components of iron bearing mafic minerals pyroxenes olivine and smaller amounts if any of volcanic glass several smaller lpds also show substantial highland components three classes of very large deposits can be distinguished from most lpds and from each other on the basis of crystallinity and possible titanium content of their pyroclastic components one class has spectral properties that are dominated by high titanium crystallized black beads e g taurus littrow a second consists of a mixture of high titanium glasses and beads with a higher glass bead ratio sulpicius gallus than that of taurus littrow and a third has a significant component of quenched iron bearing volcanic glasses aristarchus with possible moderate titanium contents although areally extensive these three classes of very large pyroclastic deposits compose only 20 of the 75 deposits studied 27 and eruption of such materials was thus likely to have been less frequent on the moon

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

lunar rare earth element distribution and ramifications for feo and tio2 lunar prospector neutron spectrometer observations lunar prospector neutron spectrometer data have been used to map the global surface distribution of the incompatible rare earth elements gadolinium and samarium from the low altitude 30 15 km mapping orbit these results afford improved surface resolution and detailed views of the potassium rare earth elements and phosphorus kreep distribution within and around mare imbrium and elsewhere the gd and sm results serve as a complementary and independent check of the distribution of kreep on the moon in contrast with the lunar prospector gamma ray spectrometer results for thorium the neutron spectrometer observations reflect the presence of fe and ti as well as gd and sm the contributions of fe and ti are removed using high spatial resolution clementine spectral reflectance determinations of feo and tio2 abundances overall the resulting gd and sm abundance map agrees with the th abundance map determined using the lunar prospector gamma ray spectrometer in general the detailed features of the procellarum imbrium kreep terrane are found in both for example distinct highs in gd sm and th abundances are resolved over the craters mairan aristarchus kepler reinhold lalande and aristillus over the apennine bench and fra mauro regions and over the montes jura and montes carpatus indicating an enhanced abundance of kreep in these locations the neutron observations also provide constraints on feo and tio2 abundances for some high ti locales there is a significant disagreement with tio2 abundances inferred from clementine spectral reflectance

geology tectonism and composition of the northwest imbrium region abstract the objective of this study is to explore the regional geology of the northwest imbrium region in which the chang e 3 ce 3 landing site is located ce 3 successfully landed on december 14 2013 on the unsampled eratosthenian basalts whose study is important for understanding the evolution of the moon new geologic and structural maps of the research area were produced through the integrated analysis of diverse datasets the highlands surrounding imbrium differ from typical farside highlands terrain fht the iridum highland region as well as the surrounding imbrium region exhibits elevated concentrations of fe and abundant local exposures of low ca pyroxene and olivine bearing lithologies in this study these highlands are named as mafic highlands mh our dating results using crater size frequency distributions csfds show that the iridum basin hosting sinus iridum was formed 3 8 ga shortly following the imbrium basin formation and before the last large multiringed basin orientale the eratosthenian period of lunar basalt eruptions which lasted longer than other stratigraphic units is suggested to divide into the lower eratosthenian mare lem and upper eratosthenian mare uem units this subdivision is based on whether lava fronts can be clearly seen or not and the age separating the units is 2 35 ga the mafic mineralogy of the mare basalts in imbrium is characterized by abundant olivine in the eratosthenian aged basalts and average pyroxene compositions near pigeonite to sub calcic augite in the imbrian and em1 units the thickness of individual lava for uem units is 8 11 m indicative of high effusion rates the thickness of the em3 unit ranges from 17 m to 45 m with lesser thickness to the west and greater thickness in the interior and to the east the estimated volume and average flux of the eratosthenian aged basalts are greater than previously thought the presence of these youngest basalts in the procellarum kreep terrain pkt is hypothesized to be a causal relationship with the pkt terrain reducing the thickness of the lithosphere and permitting preferential dike emplacement and extrusion there we speculate that high ti and olivine rich composition in late stage basalts may be consistent with low si and high ti and low degrees of partial melting large numbers of sinuous rilles and small ridges are identified and mapped many young ridges were found inside imbrium suggesting a very extended period at least as young as the last 50 ma of the moon s tectonic activity the distinct compositions of both highlands and mare basalts and extended tectonism emphasize how the imbrium basin is an important area for understanding the moon

compositional variability of the marius hills volcanic complex from the moon mineralogy mapper m3 1 using the moon mineralogy mapper m3 we examine the marius hills volcanic complex for the first time from 0 46 to 2 97 m the integrated band depth at 1 m separates the mare basalts on the plateau in two units 1 a strong 1 m band unit of localized lava flows within the plateau that has similar olivine rich signatures to those of the nearby oceanus procellarum and 2 a weaker 1 m band unit that characterizes most of the basalts of the plateau which is interpreted as having a high calcium pyroxene signature domes and cones within the complex belong to the high calcium pyroxene plateau unit and are associated with the weakest 1 m band observed on the plateau this difference could be the result of higher silica content more opaque minerals and or a weaker olivine content of the magma finally the floor of marius crater has one of the strongest olivine rich signatures of the entire marius hills complex these compositional differences are indicative of the long and complex volcanic history of the region the first episode started before the emplacement of the surrounding basalts of the plateau and produced the high calcium pyroxene flows present on the plateau and their associated domes and cones the second episode occurred concurrently or slightly after the emplacement of the adjacent procellarum basalts and produced the olivine rich basalts seen within the plateau outside the plateau and in marius crater if the olivine content of the lava flows increases with time the olivine rich region on the floor of marius crater may represent one of the latest episodes of volcanism exposed on the marius hills complex

a sharper view of impact craters from clementine data the ultraviolet visible camera on the clementine spacecraft obtained high spatial resolution images of the moon in five spectral channels impact craters mapped with these multispectral images show a scale of lithologic diversity that varies with crater size and target stratigraphy prominent lithologic variations feldspathic versus basaltic occur within the south wall of copernicus 93 kilometers in diameter on the scale of 1 to 2 kilometers lithologic diversity at tycho 85 kilometers in diameter is less apparent at this scale although the impact melt of these two large craters is remarkably similar in this spectral range the lunar surface within and around the smaller crater giordano bruno 22 kilometers in diameter is largely dominated by the mixing of freshly excavated material with surrounding older soils derived from a generally similar feldspathic lithology

abundance and distribution of iron on the moon the abundance and distribution of iron on the moon is derived from a near global data set from clementine the determined iron content of the lunar highlands crust 3 percent iron by weight supports the hypothesis that much of the lunar crust was derived from a magma ocean the iron content of lower crustal material exposed by the south pole aitken impact basin on the lunar farside is higher 7 to 8 percent by weight and consistent with a basaltic composition this composition supports earlier evidence that the lunar crust becomes more mafic with depth the data also suggest that the bulk composition of the moon differs from that of the earth9s mantle this difference excludes models for lunar origin that require the earth and moon to have the same compositions such as fission and coaccretion and favors giant impact and capture

composition and exposure age of the apollo 16 cayley and descartes regions from clementine data normalizing the optical effects of space weathering in order to quantitatively assess the composition of the lunar surface from reflectance spectroscopy it is necessary to be able to differentiate between the optical effects due to composition and those due to exposure to space weathering processes laboratory analyses of returned lunar soils are used to show that limited quantitative compositional information and the exposure age of the lunar surface can be determined using straightforward calculations from remotely acquired reflectance data sampled with a small number of spectral channels exposure age approximated by is feo where is is the characteristic ferromagnetic signal from single domain iron metal is estimated using a ratio of the reflectance at a wavelength outside of the 1 m ferrous iron absorption band to the reflectance at a wavelength within the band the iron plus titanium content of a soil can then be calculated from its is feo and reflectance these combined techniques are applied to clementine uvvis multispectral data of the lunar highlands in the vicinity of the apollo 16 landing site the is feo and feo tio2 contents are calculated for this region materials associated with recently formed impact craters and recent and or ongoing downslope movement are easily detected as nonmature the feo tio2 content of the descartes mountains is found to be 1 2 wt less than the cayley plains west of the apollo 16 landing site localized areas of compositional heterogeneity associated with some small impact events are also revealed a model for normalizing the optical contribution due to exposure to space weathering processes is applied to the clementine uvvis data in order to bring the data to an equivalent mature exposure state this approach allows residual spectral differences between the observed materials to be confidently interpreted as being due to compositional differences alone rather than to differences both of composition and of exposure the exposure normalized data reveal that this region of the highlands is characterized by limited large scale compositional heterogeneity that is detectable by a small number of spectral bandpasses the descartes mountains are identified as being more anorthositic than the cayley plains units most small impacts in the region excavated material compositionally similar to material surrounding them with the notable exceptions of the impacts that created south ray crater and an unnamed crater on the floor of abulfeda

detectability of subsurface interfaces in lunar maria by the lrs selene sounding radar influence of mineralogical composition 1 the lunar radar sounder lrs of the selene mission has detected horizontal subsurface features at depths of a few hundreds of meters within all major lunar maria we have mapped these features at global scale and found a heterogeneous geographical distribution which correlates negatively with the maps of tio 2 and feo obtained from uv vis measurements by the clementine probe high concentration of ilmenite fetio 3 in the basaltic mare lava can explain this correlation this mineral being a strong absorber for low frequency electromagnetic waves thus absence of detection of subsurface interfaces by lrs on a large portion of lunar maria does not necessarily imply that these interfaces are actually absent

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

spacecraft instrument technology and cosmochemistry measurements by instruments on spacecraft have significantly advanced cosmochemistry spacecraft missions impose serious limitations on instrument volume mass and power so adaptation of laboratory instruments drives technology we describe three examples of flight instruments that collected cosmochemical data element analyses by alpha particle x ray spectrometers on the mars exploration rovers have revealed the nature of volcanic rocks and sedimentary deposits on mars the gamma ray spectrometer on the lunar prospector orbiter provided a global database of element abundances that resulted in a new understanding of the moon s crust the ion and neutral mass spectrometer on cassini has analyzed the chemical compositions of the atmosphere of titan and active plumes on enceladus

thorium abundances on the lunar surface measurements of absolute thorium abundances on the lunar surface are presented using both the high and low altitude data taken with the lunar prospector gamma ray spectrometer an analysis of the uncertainties shows that the measured uncertainties are 7 g g are likely small area regions 150 km 2 using lunar topographic data we have shown that the thorium abundances in the lunar high lands and portions of south pole aitken spa basin are larger for lower elevations we have also studied a number of regions with anomalously high thorium abundances such as the northwestern region of spa basin the crater arago in western tranquillitatis and the compton belkovich region in the northeastern highlands the compton belkovich region appears to be enriched with evolved rocks such as alkali anorthosite and currently represents the only such extended region on the moon that has been identified in contrast tycho crater has very low thorium abundances which suggests that kreep was not assimilated at depth in this portion of the moon

olivine bearing lithologies on the moon constraints on origins and transport mechanisms from m 3 spectroscopy radiative transfer modeling and grail crustal thickness abstract high resolution hyperspectral data from chandrayaan 1 s moon mineralogy mapper m 3 allow detection of olivine on the lunar surface olivine exposed at the surface may originate as mantle material or igneous products intrusive or extrusive potential transport mechanisms include excavation of the mantle or lower crustal material by impacts that form basins and complex craters differentiation of impact melt sheets or magmatic emplacement of lavas cumulates or xenoliths a sample of the lunar mantle which has not been conclusively identified in the lunar sample collection would yield fundamental new insights into the composition structure and evolution of the lunar interior olivine identified in remote spectral data is generally accepted to originate from the primary mantle because abundant olivine is expected to exist in the mantle and lower crust yet have sparse occurrences in the upper crust in this study we identified 111 m 3 single pixel spectra with characteristic absorption features consistent with olivine at crisium nectaris and humorum basins and near the craters roche and tsiolkovsky in an effort to determine the origins and transport mechanisms that led to these individual exposures we estimated mineral abundances using radiative transfer modeling and examined crustal thickness estimates topography and slope maps and images from the lunar reconnaissance orbiter camera lroc at crisium basin where crustal thickness is near 0 km wieczorek et al 2013 mantle olivine may have been exposed by basin forming impact and deposited on the rim picard crater which is superposed on the floor of crisium also exhibits potential mantle olivine in its ejecta within nectaris basin olivine exposures are confined to the rims of small craters on the mare which are inferred to excavate a layer of olivine rich mare basalt olivine occurrences on the rim of humorum basin including those located on a graben are likely to be cumulates of shallow intrusions that were transported magmatically to the surface near roche crater olivine may have originated in shallow dikes that reached the subsurface and were exposed by impacts in addition to verifying both known and previously unidentified olivine exposures our combined geophysical spectral and radiative transfer modeling investigation has allowed identification of both igneous and mantle derived olivine

thermal and magmatic evolution of the moon as with all science our continually developing concepts of lunar evolution are firmly tied to both new types of observations and the integration of these observations to the known pool of data this process invigorates the intellectual foundation on which old models are tested and new concepts are built just as the application of new observational tools to lunar science in 1610 galileo s telescope and 1840 photography yielded breakthroughs concerning the true nature of the lunar surface the computational and technological advances highlighted by the apollo and post apollo missions and associated scientific investigations provided a new view of the thermal and magmatic evolution of the moon 1 1 pre apollo view of the thermal and magmatic evolution of the moon many of the early views of the moon manifested in mythology and art throughout the world were primarily tied to lunar and terrestrial cycles and the relationships between the sun and the moon prophetically myths involving the lunar deities mwuetsi from zimbabwe and coyolxauhqui from mexico told of rather violent or catastrophic events in which the moon was expunged from the earth numerous ancient scientific observations were made about the nature of the moon ranging from those uncovered in early neolithic sites that correctly identified mare crisium and mare humorum to the insights made by greek philosophers such as anaxagoras ca 500 428 b c and democritus ca 460 370 b c who attached terrestrial analogues to its character stone mountains with the advent of the telescope 1610 and photography 1840 as scientific tools for lunar exploration semiquantitative data could be collected that would provide an intellectual foundation for scientific interpretation initially modern terrestrial geological analogs were extended to the moon lunar highlands volcanic craters seas combined with the rigors of computational modeling these observational data were extended to predict the original thermal state of the moon and its thermal and magmatic history its proximity to the earth

evolution of the upper mantle of the earth s moon neodymium and strontium isotopic constraints from high ti mare basalts isotopic studies of mare basalts have led workers to conclude that their sources are heterogeneous on both large and small scales furthermore these studies have led workers to postulate that depletion within the lunar mantle occurred early in its evolution and was a result of accumulation of mafic minerals from a lree enriched magma ocean high ti basalts from the apollo 1 i and 17 landing sites and ilmenite basalts from apollo 12 are secondary evidence of this extreme early depletion event kreepy rocks are the complementary enriched component in the moon a total of fourteen high ti basalts have now been analyzed from the apollo 11 landing site for neo dymium and strontium isotopes a sm nd internal isochron on basalt 10058 yields an age of 3 70 0 06 ga similar to 40ar 39ar ages of other group b 1 basal a compilation of all previously determined ages on apollo 11 high ti basalts indicates four distinct phases of volcanism at 3 85 0 02 ga group b2 3 71 f 0 02 ga group b3 3 67 0 02 ga group bl and 3 59 f 0 04 ga group a whole rock sm nd isotopic data for all apollo 11 high ti basalts form a linear array which yields the age of the moon 4 55 f 0 30 ga a similar regression of all uncontaminated high ti basalts from the moon both apollo 11 and apollo 17 yields an age of 4 46 0 17 ga both arrays are interpreted as average source ages of the high ti basalts and are consistent with the formation of these sources by precipitation of cumulates from a magma ocean early in the history of the moon these new strontium and neodymium isotopic data coupled with previously published data are con sistent with a two component model for the upper mantle of the moon these two components include mafic adcumulates precipitated from a magma ocean prior to 4 4 ga and small amounts 2 of trapped kreepy late stage magma ocean differentiates the mafic adcumulate evolves from 4 5 ga with 47sm 44nd 0 318 and rb r 0 005 to extremely radiogenic neodymium isotopic ratios and very unradiogenic strontium isotopic ratios the kreepy trapped liquid has a 14 sm 44nd 0 168 and rb r 0 235 and thus evolves toward very unradiogenic neodymium and radiogenic strontium isotopic ratios because the kreepy trapped liquid is enriched in both rubidium and the rees by over an order of magnitude compared to the mafic adcumulate trapping of even small proportions of this liquid in the adcumulate will control the radiogenic isotopic composition of the source the apparent heterogeneity in the source regions of mare basalts could be caused by trapping of variable yet small proportions of this lile enriched liquid in the cumulate pile

mare tranquillitatis basalt emplacement history and relation to lunar samples galileo and clementine multispectral data of the mare tranquillitatis region have been analyzed to investigate the stratigraphy of basaltic units and the effects of lateral and vertical mixing processes within the mare the distribution of compositionally distinct mare units is observed to be correlated with previous uv vis ratio images although estimates of soil titanium contents are low in some areas as a result of mixing of local basalts with nonmare feldspathic materials basalt units identified by their spectral properties and spectral mixture analysis are compared with groups of apollo 11 samples defined by previous workers on the basis of age and chemistry spectral studies presented here indicate that the apollo 11 site lies at the edge of a localized western mare unit which includes the youngest and most titanium rich basalts in tranquillitatis apollo 11 high k high ti samples in southern tranquillitatis these basalts have been contaminated by a large degree of mixing with nonmare feldspathic materials nonmare materials near the apollo 11 site are attributed largely to crater rays from theophilus 100 km in diameter which is located approximately 300 km to the south a more extensive and stratigraphically older unit exposed near apollo 11 is related to the low k high ti apollo 11 samples and appears to extend as a coherent surface unit as far north as the apollo 17 site in southern serenitatis the distribution of this spectrally identified basalt unit supports petrologic and geochemical evidence for the grouping of the high ti low k apollo 11 and 17 basalt samples into the same regional volcanic events multispectral analysis of tranquillitatis deposits also identify low titanium basalts in the northeastern and southeastern portions of the basin that are older than the high ti basalts and are believed to be unsampled by apollo 11 several lines of evidence suggest that the cayley formation along the western tranquillitatis margin may indeed lie on top of an ancient mare deposit buried by imbrium basin ejecta e g a cryptomare deposit the distribution of vertically excavated feldspathic premare material within the mare provides information on the depth of the mare units and the proximity of the underlying basin topography compositional stratigraphy observed in both sets of multispectral data supports an asymmetric premare fill basin topography containing thicker basalts in the northwestern portion of the basin than previously predicted by crater flooding data

minerals mapping of the lunar surface with clementine uvvis nir data based on spectra unmixing method and hapke model the distribution of minerals on the lunar surface is information which could contribute to studying lunar origin and evolution in this paper the distribution of clinopyroxene orthopyroxene olivine ilmenite and plagioclase on the lunar surface has been mapped based on hapke radiative transfer model and linear unmixing of spectra with clementine uvvis nir data the results have been validated on the basis of minerals modal abundance data of the apollo samples and problems in the minerals abundance mapping have been analyzed the validation based on analysis data of apollo samples indicates that plagioclase mapped in this paper represents the total abundance of plagioclase and agglutinitic glass the minerals mapping results show that the lunar surface is mainly composed of pyroxene plagioclase agglutinitic glass and ilmenite basalt in the lunar mare is mainly composed of clinopyroxene and ilmenite and lunar highland is mainly composed of plagioclase and agglutinitic glass orthopyroxene is mainly distributed on the north of mare imbrium on the south of maria and aitken basin according to our results there is probably no large area of olivine distribution on the lunar surface which is different from earlier published results therefore emphasis should be put on the olivine distribution in the minerals mapping using hyperspectral data such as m3 of chandrayaan 1 and iim of change 1

remote sensing of potential lunar resources 1 near side compositional properties new telescopic ccd multispectral imaging of the lunar near side and 330 870 nm spectroscopy of selected regions are presented as aids in estimating compositional differences relevant to locating potential lunar resources such as ilmenite fetio3 and solar wind implanted 3he and h conversion of 400 560 nm ccd ratio images to weight percent tio2 using a version of the charette et al 1974 empirical relation allows construction of a new tio2 abundance map for the lunar maria accurate to 2 wt ho2 this map provides a consistent view of tio2 distribution among mature mare soils and can be used to estimate areas potentially rich in ilmenite western mare tranquillitatis exhibits the highest tio2 abundances 8 wt followed by regions near flamsteed p and in northern oceanus procellarum a 950 560 nm ccd ratio mosaic of the full moon provides estimates of relative surface maturity on local scales as defined by the degree of agglutinate production due to micrometeorite impacts since high 3he concentrations are correlated with mature ilmenite rich soils a combination of relative surface maturity maps and tio2 abundance maps may be useful for estimating 3he and possibly h distribution on local scales while dark mantle materials are also potential sources of ilmenite 3he and h their compositional differences from mare soils prevent accurate remote mapping of their tio2 abundance and relative maturity reflectance spectra relative to a more rigorously defined ms 2 standard region of dark mantle materials and high tio2 mare areas exhibit previously undocumented near uv 350 nm changes in spectral slope apparently related to compositional variations determination of the primary lunar sites for resource utilization will be dictated by the future goals and priorities of the lunar resource program

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

early organic diagenesis the significance of progressive subsurface oxidation fronts in pelagic sediments abstract porewater and solid phase geochemical data at two contrasting ne atlantic stations are reported station 10552 on the cape verde abyssal plain is a site of slow pelagic accumulation ca 0 4 cm kyr 1 molecular oxygen is present in the sediment column to at least 2 m and probably much deeper labile organic carbon is almost totally consumed in the upper few centimetres of the sediment by contrast at station 10554 on the madeira abyssal plain the pelagic sequence has been interrupted by the occasional deposition of organic rich turbidites porewater oxygen and nitrate profiles show that subsurface organic metabolism of the organic carbon associated with the uppermost turbidite layer is a significant fraction of the overall metabolism in the sediment column this metabolism occurs at a relatively thin reaction front which progresses deeper into the turbidite with time this phenomenon exerts a controlling influence on the present nutrient profile and redox succession in a less extreme form substrate distributions of this latter type are not uncommon in atlantic sediments a model has been developed which is controlled by both oxygen and nitrate data this model permits a vertical profile of metabolic activity to be derived and also gives estimates of the reaction rate constants and solid phase mixing rates at these two contrasting stations about 30 of the total activity at station 10554 is located within the turbidite at the deepening reaction front this is a non steady state condition in fact it is found that the integrated metabolic activity at the two stations is not dissimilar ca 1 2 10 13 moles cm 2 sec 1 the striking differences in redox profile are therefore primarily attributable to differences in the distribution of metabolic activity within the column

remote sensing of potential lunar resources 2 high spatial resolution mapping of spectral reflectance ratios and implications for nearside mare tio2 content high spatial resolution maps illustrating variations in spectral reflectance 400 560 nm ratio values have been generated for the following mare regions 1 the border between southern mare serenitatis and northern mare tranquillitatis including the ms 2 standard area and apollo 17 landing site 2 central mare tranquillitatis 3 oceanus procellarum near seleucus and 4 southern oceanus procellarum around flamsteed we have also obtained 320 1000 nm reflectance spectra of several sites relative to ms 2 to facilitate scaling of the images and provide additional information on surface composition inferred tio2 abundances for these mare regions have been determined using an empirical calibration which relates the weight percent tio2 in mature mare regolith to the observed 400 560 nm ratio mare areas with high tio2 abundances are probably rich in ilmenite fetio3 a potential lunar resource the highest potential tio2 concentrations we have identified in the nearside maria occur in central mare tranquillitatis inferred tio2 contents for these areas are 9 wt and are spatially consistent with the highest tio2 regions mapped previously at lower spatial resolution we note that the morphology of surface units with high 400 560 nm ratio values increases in complexity at higher spatial resolutions new telescopic spectra of landing sites successfully reproduce the charette relation although we find that the 400 560 nm value is strongly a fimction of the sample area size the increased spectral contrast of the 400 730 nm ratio over the 400 560 nm ratio demonstrates the potential increased precision with which the 400 730 nm ratio might be used to estimate tio2 abundances comparisons have been made with previously published geologic maps lunar orbiter iv and ground based images and some possible morphologic correlations have been found between our mapped 400 560 nm ratio values and volcanic landforms such as lava flows mare domes and collapse pits

lunar iron and titanium abundance algorithms based on final processing of clementine ultraviolet visible images the clementine mission to the moon returned global imaging data collected by the ultraviolet visible uvvis camera this data set is now in a final state of calibration and a five band multispectral digital image model dim of the lunar surface will soon be available to the science community we have used observations of the lunar sample return sites and stations extracted from the final dim in conjunction with compositional information for returned lunar soils to revise our previously published algorithms for the spectral determination of the feo and tio2 content of the lunar surface the algorithms successfully normalize the effects of space weathering so that composition may be determined without regard to a surface s state of maturity these algorithms permit anyone with access to the standard archived dim to construct high spatial resolution maps of feo and tio2 abundance such maps will be of great utility in a variety of lunar geologic studies

integrated spectral analysis of mare soils and craters applications to eastern nearside basalts abstract high spatial resolution clementine images are examined to measure the reflectance properties of small and optically immature mare craters that have sampled discrete compositional units the spectral properties of these relatively crystalline mare materials are compared to associated mature soils to determine the effects of space weathering on specific basalt types space weathering is observed to alter the optical properties of distinct lunar basalt units in a systematic manner allowing compositional distinctions to be recognized across maturity states ultraviolet visible reflectance properties of mare basalts are sensitive to titanium content but are relatively independent of maturity state and demonstrate only a slight reddening as regoliths mature to soils other compositional distinctions between basalt types are identified by differences in albedo and band strength of ferrous minerals that are maintained over a full range of maturity states immature deposits within large craters are compared to the spectral properties of well defined mare units to examine the composition of buried materials when craters excavate through the mare highland contamination is readily identified as a mixing relation between mafic and feldspathic lithologies the approach presented here provides new information on the composition and stratigraphy of several nearside mare deposits including the identification of thin low iron and very low titanium basalts in lacus somniorum and more iron rich low titanium basalts in eastern mare frigoris

clementine images of the lunar sample return stations refinement of feo and tio2 mapping techniques clementine uvvis images of the lunar sample return sites have been processed and used to produce refined calibrations for the iron and titanium determination algorithms of lucey et al 1995 1996 the high spatial resolution of the clementine data permits individual sampling stations to be resolved at the apollo 15 16 and 17 landing sites we find an excellent linear correlation between the spectral fe and ti parameters and the average feo and tio 2 contents of soils sampled at each site or station this correlation demonstrates that these techniques can confidently be applied to other areas of the moon the luna 24 site does not fit the ti relation found for other sites suggesting that either its sample is nonrepresentative or the reported landing coordinates are incorrect

mineralogical variation of the late stage mare basalts the last major phases of lunar volcanism occurred mainly in oceanus procellarum and mare imbrium and produced spectrally unique medium and high titanium basalts the composition and distribution of these basalts provide a record of the late stage thermal evolution of the moon to study the spectral and mineralogical variations of the late stage mare basalts 31 distinct units were mapped employing a range of remote sensing data their inferred mineralogical characteristics were studied by analyzing the spectral features of small fresh craters derived from the moon mineralogy mapper m3 data the strongest olivine spectral signatures were found around lichtenberg crater while the units with the lowest olivine pyroxene ratio occurred mainly in the southern kepler crater and some local areas in oceanus procellarum the olivine pyroxene ratio decreases progressively from the lichtenberg crater to the southern units the northern and southern units within mare imbrium have higher olivine pyroxene ratios than the central ones the inferred abundance of olivine appears to vary stratigraphically with the younger flows being more olivine rich however the stratigraphically younger units around euler crater in mare imbrium which present as dark red hues in the integrated band depth image of m3 were found to have lower olivine pyroxene ratios than the units around lichtenberg crater shown as light red hues in oceanus procellarum it could be interpreted that the late stage mare basalts around lichtenberg crater originated from a more olivine rich source than those around euler crater

a comparative study of iron abundance estimation methods application to the western nearside of the moon abstract the feo weight percentage wt abundance of the moon s western nearside 55 s 55 n and 5 e 40 w is estimated using data from the infrared spectrometer 2 sir 2 and the moon mineralogy mapper m3 in this study we modified an feo abundance estimation algorithm bhatt m mall u bugiolacchi r mckenna lawlor s banaszkiewicz m nathues a ullaland k 2012 icarus 220 51 64 which relies exclusively on the 2 m absorption band parameters the modified feo abundance estimation algorithm and the regression based elemental abundance estimation algorithm wohler c grumpe a berezhnoy a bhatt m u mall u 2014 icarus 235 86 122 which is based on the 1 m and 2 m absorption band parameters is applied to the m3 data we have compared results obtained from these two modified algorithms with a previously published clementine s feo wt map lucey p g blewett d t jolliff b l 2000 j geophys res 105 20297 20306 the effects of topography and space weathering on feo wt estimates have been successfully minimized using the modified algorithm based on the 2 m absorption band parameters thus this algorithm can be successfully applied at middle to high latitudes furthermore a correction for tio2 is applied to the feo abundance estimation algorithm based on the 2 m absorption band parameters using the m3 data our comparative study shows a good correspondence between the three algorithms discussed there are two locations the crater tycho and the region around rima bode which show major discrepancies our modified algorithm based on the 2 m absorption parameters predicts 3 4 wt less feo for the ray system of tycho than for the surrounding region the average iron abundance for the lunar highlands is about 6 wt and for the mare regions is about 16 wt using the regression based elemental abundance estimation algorithm and the algorithm based on the 2 m absorption parameters this result is consistent with the previous analysis using lunar prospector gamma ray spectrometer data sets the feo wt is in the range 20 24 wt for the high ti basalts using both the modified iron abundance estimation and the regression based elemental abundance estimation algorithms

distribution of exchangeable fixed organic and total nitrogen in interbedded turbiditic pelagic sediments of the madeira abyssal plain eastern north atlantic abstract nitrogen compounds in the interbedded turbiditic pelagic sediments of the madeira abyssal plain from hereon map have been divided in separate extracted fractions such as exchangeable nitrogen nex fixed nitrogen nfix and organic nitrogen norg nex is found to be directly proportional to the amount of organic matter corg in the sediment and is not related to the amount of ammonium in the porewater only at a relatively low corg content is the nex determined by the mineralogy of the sediment the norg as determined from norg ntot nfix nex is strongly related with corg the nfix content and the n fix al ratio for organic rich sediments are high compared with other sediments and have not changed upon post depositional oxidation of the organic matter post depositional oxidation of organic matter through oxygen does lead to a decrease in the c n ratio of the remaining organic matter in the organic rich turbidites the c n ratio calculated for the organic matter that has been decomposed through oxygen is similar to that calculated through stoichiometric modelling for decomposition under reducing circumstances c n ratios of 17 and 18 respectively this implies that for the sediments of the map the c n ratio is identical for organic matter decomposed under oxygenated and under reducing conditions

polar hydrogen deposits on the moon neutron and gamma ray data measured using the lunar prospector spectrometers were analyzed to define the enhanced hydrogen deposits near both poles of the moon combining the new low altitude neutron data 30 15 km with previous high altitude 100 20 km neutron data and the results of several recent radar investigations sharply constrains the characteristics of each of the polar deposits the deposits at the north appear to be in the form of many small pockets or of generally distributed hydrogen that average to a 100 ppm weight fraction enhancement over that which exists in regolith at more equatorial latitudes those deposits in the permanently shaded craters near the south pole are consistent with a thick ferroan anorthosite regolith containing an enhancement of 1670 890 ppm hydrogen which if in the form of water ice amounts to 1 5 0 8 weight fraction of h sub 2 o neutron data alone cannot discriminate between hydrogen implanted in lunar soil from the solar wind hydrated minerals or h sub 2 o these craters appear to be surrounded by regolith that either contains small pockets of enhanced hydrogen or is soil that is uniformly impregnated with hydrogen enhanced on average by about 100 ppm above that contained in soils at more equatorial latitudes c more 2000 american geophysical union less

cratering history and lunar chronology the moon is exceptional and important because it is the only planetary body besides the earth for which we have both a detailed stratigraphic history and datable rock samples that can be related to specific geomorphologic units fig 5 1 the moon has preserved much of its magmatic and impact record of at least the last 4 billion years while its endogenic history is of great interest for the fundamentals of planetary interiors and surfaces the moon has become a calibration plate for the cratering record of the earth moon system and by extrapolation of the entire inner solar system if one assumes a heliocentric origin for impactor populations these populations range from asteroids through long and short period comets to interplanetary dust and cover a size range from hundreds of kilometers to micrometers figure 5 1 telescopic view of the nearside of the earth s moon with landing sites of the apollo and luna missions this chapter reviews the presently available data sets in support of this paradigmatic assumption as follows 1 the phenomenology of lunar impact craters 2 the terrestrial record of the impact cratering process and the interpretation of terrestrial impactites as far as this ground truth is relevant for the interpretation of lunar impact craters and datable lunar impact breccias and melt rocks 3 the theory and numerical simulation of the cratering process and the characteristics of the earth moon crossing population of impactors asteroids and comets 4 the principles of relative age dating of lunar surface units and the general lunar stratigraphy 5 the stratigraphic significance and ages of lunar samples impactites and basalts and based on this data set the absolute ages of lunar surface units 6 the cratering rate of the moon as a function of time and 7 the time calibration of this cratering rate based on the

a chemical model for generating the sources of mare basalts combined equilibrium and fractional crystallization of the lunar magmasphere abstract it is generally considered that mare basalts were generated by the melting of a cumulate mantle formed in an early moon wide magma ocean or magmasphere however the nature and chemistry of this cumulate mantle and the logistics of its origin have remained elusive extensive studies of terrestrial layered mafic intrusions over the past sixty years have emphasized the imperfection of fractional crystallization and attendant crystal crystal and crystal liquid separation in a convecting magma chamber crystal liquid and crystal crystal separations were similarly inefficient during evolution of the lunar magma ocean lmo allowing for the trapping of interstitial liquid and entrainment of a small proportion of less dense plagioclase into the denser mafic cumulate mush indeed petrography of lunar highlands samples demonstrates this for anorthosites with 1 10 olivine the residual liquid after 80 90 crystallization was very evolved in fact kreepy and even in small proportions 1 5 would have a noticeable effect on the trace element chemistry of melts generated from these cumulates this trapped residual liquid would elevate total ree abundances in the cumulate pile while synchronously deepening the already negative eu anomaly essentially this trapped liquid will make the cumulate more fertile for melting to generate both kreep basalt and mare basalt magmas plagioclase entrained in the mafic cumulate pile adds an essential al component to the high ti basalt source and will moderate the requisite negative eu anomaly in the cumulate early in the evolution of the lunar mantle when the lmo still was largely liquid it is likely that vigorous convection was an important factor in crystallization such convection would allow crystals to remain suspended and in equilibrium with the lmo liquid for relatively long periods of time this extended period of equilibrium crystallization would then have been followed by fractional crystallization once plagioclase became a liquidus phase and began to float to form the lunar highlands crust previous authors have proposed a three component model for the evolution of high ti mare basalt source regions this model includes kreep early olivine rich high mg cumulates and late ilmeniterich low mg cumulates in various proportions however we propose a model for high ti basalt parent magmas which is in accord with studies of terrestrial layered intrusions this model for the high ti source includes trapped instantaneous residual liquid tirl 1 3 and entrainment of a small 2 5 proportion of plagioclase into the late stage cumulate pile in order to account for both the observed al compositions and trace element characteristics of high ti mare basalts melting of this relatively shallow ilmenite and clinopyroxene bearing late stage cumulate can generate high ti mare basalt magmas furthermore we are in agreement with other workers that only through a process of nonmodal melting will the high ti values for the parent magmas be realized large scale convective overturn of the cumulate pile and mixing of kreep with early and late stage cumulates is not required however localized overturn of the upper tenth of the cumulate pile is likely and in fact required to achieve an appropriate major element balance for the high ti mare basalt source region

geology and scientific significance of the rumker region in northern oceanus procellarum china s chang e 5 landing region the rumker region 41 45 n 49 69 w is located in northern oceanus procellarum of the moon mons rumker is the most distinctive geological feature in the area the region is characterized by prolonged lunar volcanism late imbrian period to eratosthenian period forming multiple geologic units in the area including very low ti to low ti mare basalts high ti mare basalts and volcanic complexes each geologic unit has distinct element composition and mineral assemblages the rumker region overlying the procellarum kreep terrain was selected as the landing region for china s chang e 5 lunar sample return mission prelanding analyses of the geologic context and scientific potential are reported in this contribution we conducted detailed geological mapping using image spectral and altimetry data fourteen geological units were defined a geologic map was constructed and the geologic history was outlined the western mare units im1 im2 and im3 are imbrian aged 3 4 3 5 ga representing the major stage of lunar mare eruptive volcanism the eastern young mare units em3 and em4 2 ga are among the youngest mare basalts on the moon they have never been explored in situ or studied in the laboratory we suggest that samples returned from the eastern mare unit em4 could answer many fundamental questions and that this unit should be listed as the top priority landing site for chang e 5 sample return mission

compositional diversity and geologic insights of the aristarchus crater from moon mineralogy mapper data 1 the moon mineralogy mapper m3 acquired high spatial and spectral resolution data of the aristarchus plateau with 140 m pixel in 85 spectral bands from 0 43 to 3 0 m the data were collected as radiance and converted to reflectance using the observational constraints and a solar spectrum scaled to the moon sun distance summary spectral parameters for the area of mafic silicate 1 and 2 m bands were calculated from the m3 data and used to map the distribution of key units that were then analyzed in detail with the spectral data this analysis focuses on five key compositional units in the region 1 the central peaks are shown to be strongly enriched in feldspar and are likely from the upper plagioclase rich crust of the moon 2 the impact melt is compositionally diverse with clear signatures of feldspathic crust olivine and glass 3 the crater walls and ejecta show a high degree of spatial heterogeneity and evidence for massive breccia blocks 4 olivine strongly concentrated on the rim wall and exterior of the southeastern quadrant of the crater is commonly associated the impact melt 5 there are at least two types of glass deposits observed pyroclastic glass and impact glass

the mineralogy of late stage lunar volcanism as observed by the moon mineralogy mapper on chandrayaan 1 1 the last major phases of lunar volcanism produced spectrally unique high titanium basalts on the western nearside of the moon the moon mineralogy mapper m3 on chandrayaan 1 has provided detailed measurements of these basalts at spatial and spectral resolutions necessary for mineralogical interpretation and mapping of distinct compositional units the m3 imaging spectrometer acquired data in 85 spectral bands from 430 to 3000 nm at 140 to 280 m pixel in its global mapping mode during the first half of 2009 reflectance data of several key sites in the western maria were also acquired at higher spatial and spectral resolutions using m3 s target mode prior to the end of the chandrayaan 1 mission these new observations confirm that both fresh craters and mare soils within the western high ti basalts display strong 1 m and weak 2 m absorptions consistent with olivine rich basaltic compositions the inferred abundance of olivine is observed to correlate with stratigraphic sequence across different mare regions and absolute ages the apparent stratigraphic evolution and fe rich compositions of these basalts as a whole suggest an origin from evolved residual melts rather than through the assimilation of more primitive olivine rich sources mare deposits with spectral properties similar to these late stage high ti basalts appear to be very limited outside the procellarum imbrium region of the moon and where present appear to occur as small areas of late stage regional volcanism detailed analyses of these new data and supporting measurements are in progress to provide further constraints on the mineralogy olivine abundance and compositions of these final products of lunar volcanism and the nature and evolution of their source regions

iron abundances on the lunar surface as measured by the lunar prospector gamma ray and neutron spectrometers i global measurements of iron abundances on the lunar surface are presented using data from the lunar prospector lp gamma ray spectrometer grs and neutron spectrometer ns in this study we derive relative iron abundances from the low altitude high spatial resolution 45 km 2 lp data using the 7 6 mev neutron capture gamma ray doublet as part of the lp grs analysis we demonstrate the importance of accounting for variations in neutron number density across the lunar surface by measuring neutron fluxes using lp ns data in a first step of comparing the lp grs data with previously published iron abundances inferred from clementine spectral reflectance csr data we show that the existing csr feo data are nonlinear with respect to the lp relative iron abundances we use the lp data to linearize the relationship between the csr and the relative iron values then recalibrate the csr data to iron abundance using returned soil abundances we then correlate the csr data except for major anomalies with the lp relative iron measurements to convert the lp data to absolute iron abundances when we compare the lp grs and revised csr data sets we find a very good correspondence there are two locations mare tranquillitatis and south pole aitken spa basin that show major discrepancies suggesting that the csr data are locally overestimating iron abundances in both these regions the discrepancies identified by the lp grs csr comparison are possibly explained by mineralogical differences that are not accounted for in the csr to feo calibration in regards to our understanding of the moon the lp data have found the following i there exist large expanses of mare basalt in the western mare regions that have very high iron abundances 22 23 wt feo that are underrepresented but not absent from the returned sample collection and are highly unusual for mare soils which typically contain a significant amount of highlands contamination 2 the low iron abundances in the lunar highlands 5 feo wt are consistent with a previous analysis using thermal and epithermal neutrons and with the idea that the lunar crust formed by a relatively simple magma ocean process 3 the comparison of lp and csr derived iron abundances suggests that the material within spa basin is similar to a norite type rock without an enriched mantle feo signature 4 a comparison of lp and csr data at tycho crater shows a large discrepancy such that the csr data show moderate iron abundances of 8 9 wt feo while the lp data show very low iron abundances of 3 4 wt feo this discrepancy cannot yet be easily explained by any known process