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Supporting information file for Journal of Geophysical Research - Planets article.

International audience; The Mars Science Laboratory Curiosity rover arrived at Mars in August 2012 with a primary goal of characterizing the habitability of ancient and modern environments. Curiosity was sent to Gale crater to study a sequence of ∼3.5 Ga old sedimentary rocks that, based on orbital visible and near- to short-wave infrared reflectance spectra, contain secondary minerals that suggest deposition and/or alteration in liquid water. The sedimentary sequence in the lower slopes of Mount Sharp in Gale crater preserves a dramatic shift on early Mars from a relatively warm and wet climate to a cold and dry climate, based on a transition from smectite-bearing strata to sulfate-bearing strata. The rover is equipped with instruments to examine the sedimentology and identify compositional changes in the stratigraphy. The Chemistry and Mineralogy (CheMin) instrument is one of two internal laboratories on Curiosity and includes a transmission X-ray diffractometer (XRD) and X-ray fluorescence (XRF) spectrometer. CheMin measures loose sediment samples scooped from the surface and drilled rock powders, and the XRD provides quantitative mineralogy to a detection limit of ∼1 wt.% for crystalline phases. Curiosity has traversed >20 km since landing and has primarily been exploring an ancient lake environment fed by streams and groundwater. Of the 19 drilled rock samples analyzed by CheMin as of sol 2300 (January 2019), 15 are from fluvio-lacustrine deposits that comprise the Bradbury and Murray formations. Most of these samples were drilled from units that did not have a clear mineralogical signature from orbit. Results from CheMin demonstrate an astounding diversity in the mineralogy of these rocks that signifies geochemical variations in source rocks, transportation mechanisms, and depositional and diagenetic fluids. Most detrital igneous minerals are basaltic, but the discovery in a few samples of abundant silicate minerals that usually crystallize from evolved magmas on Earth remains enigmatic. Trioctahedral smectite and magnetite at the base of the section may have formed from low-salinity pore waters with a circumneutral pH in lake sediments. A transition to dioctahedral smectite, hematite, and Ca-sulfate going up section suggests a change to more saline and oxidative aqueous conditions in the lake waters themselves and/or in diagenetic fluids. Perhaps one of the biggest mysteries revealed by CheMin is the high abundance of X-ray amorphous materials (15–73 wt.%) in all samples drilled or scooped to date. CheMin has analyzed three modern eolian sands, which have helped constrain sediment transport and mineral segregation across the active Bagnold Dune Field. Ancient eolian sandstones drilled from the Stimson formation differ from modern eolian sands in that they contain abundant magnetite but no olivine, suggesting that diagenetic processes led to the alteration of olivine to release Fe(II) and precipitate magnetite. Fracture-associated halos in the Stimson and the Murray formations are evidence for complex aqueous processes long after the streams and lakes vanished from Gale crater. The sedimentology and composition of the rocks analyzed by Curiosity demonstrate that habitable environments persisted intermittently on the surface or in the subsurface of Gale crater for perhaps more than a billion years.

The Mars Science Laboratory rover Curiosity has been exploring sedimentary deposits in Gale crater since August 2012. The rover has traversed up section through approx.100 m of sedimentary rocks deposited in fluvial, deltaic, lacustrine, and eolian environments (Bradbury group and overlying Mount Sharp group). The Stimson formation lies unconformable over a lacustrine mudstone at the base of the Mount Sharp group and has been interpreted to be a cross-bedded sandstone of lithified eolian dunes. Mineralogy of the unaltered Stimson sandstone consists of plagioclase feldspar, pyroxenes, and magnetite with minor abundances of hematite, and Ca-sulfates (anhydrite, bassanite). Unaltered sandstone has a composition similar to the average Mars crustal composition. Alteration "halos" occur adjacent to fractures in the Stimson. Fluids passing through these fractures have altered the chemistry and mineralogy of the sandstone. Silicon and S enrichments and depletions in Al, Fe, Mg, Na, K, Ni and Mn suggest aqueous alteration in an open hydrologic system. Mineralogy of the altered Stimson is dominated by Ca-sulfates, Si-rich X-ray amorphous materials along with plagioclase feldspar, magnetite, and pyroxenes, but less abundant in the altered compared to the unaltered Stimson sandstone and lower pyroxene/plagioclase feldspar. The mineralogy and geochemistry of the altered sandstone suggest a complicated history with several (many?) episodes of aqueous alteration under a variety of environmental conditions (e.g., acidic, alkaline).

At low pressure and temperature, water ice can occur in a number of metastable states. These forms can persist over extended periods of time, up to the timescale of the solar system, due to activation energy barriers that prevent restructuring from one form into another. In this regime of temperature (T < 220 K) and pressure (P < 0.2 GPa), there is no thermodynamic equilibrium. All structural transitions are time dependent and irreversible.

Vapor-deposited amorphous water ice when warmed above the glass transition temperature (120-140 K), is a viscous liquid which exhibits a viscosity vs temperature relationship different from that of liquid water at room temperature. New studies of thin water ice films now demonstrate that viscous liquid water persists in the temperature range 140-210 K. where it coexists with cubic crystalline ice. The liquid character of amorphous water above the glass transition is demonstrated by (1) changes in the morphology of water ice films on a nonwetting surface observed in transmission electron microscopy (TEM) at around 175 K during slow warming, (2) changes in the binding energy of water molecules measured in temperature programmed desorption (TPD) studies, and (3) changes in the shape of the 3.07 micrometers absorption band observed in grazing angle reflection-absorption infrared spectroscopy (RAIRS) during annealing at high temperature. whereby the decreased roughness of the water surface is thought to cause changes in the selection rules for the excitation of O-H stretch vibrations. Because it is present over such a wide range of temperatures, we propose that this form of liquid water is a common material in nature. where it is expected to exist in the subsurface layers of comets and on the surfaces of some planets and satellites.

A series of surface-modified clays containing nanophase (np) iron oxide/oxyhydroxides of extremely small particle sizes, with total iron contents as high as found in Mars soil, were prepared by iron deposition on the clay surface from ferrous chloride solution. Comprehensive studies of the iron mineralogy in these "Mars-soil analogs" were conducted using chemical extractions, solubility analyses, pH and redox, x ray and electron diffractometry, electron microscopic imaging, specific surface area and particle size determinations, differential thermal analyses, magnetic properties characterization, spectral reflectance, and Viking biology simulation experiments. The clay matrix and the procedure used for synthesis produced nanophase iron oxides containing a certain proportion of divalent iron, which slowly converts to more stable, fully oxidized iron minerals. The clay acted as an effective matrix, both chemically and sterically, preventing the major part of the synthesized iron oxides from ripening, i.e., growing and developing larger crystals. The precipitated iron oxides appear as isodiametric or slightly elongated particles in the size range 1-10 nm, having large specific surface area. The noncrystalline nature of the iron compounds precipitated on the surface of the clay was verified by their complete extractability in oxalate. Lepidocrocite (gamma-FeOOH) was detected by selected area electron diffraction. It is formed from a double iron Fe(II)/Fe(III) hydroxy mineral such as "green rust," or ferrosic hydroxide. Magnetic measurements suggested that lepidocrocite converted to the more stable maghemite (gamma-Fe2O3) by mild heat treatment and then to nanophase hematite (alpha-Fe2O3) by extensive heat treatment. After mild heating, the iron-enriched clay became slightly magnetic, to the extent that it adheres to a hand-held magnet, as was observed with Mars soil. The chemical reactivity of the iron-enriched clays strongly resembles, and offers a plausible mechanism for, the somewhat puzzling observations of the Viking biology experiments. Their unique chemical reactivities are attributed to the combined catalytic effects of the iron oxide/oxyhydroxides and silicate phase surfaces. The reflectance spectrum of the clay-iron preparations in the visible range is generally similar to the reflectance curves of bright regions on Mars. This strengthens the evidence for the predominance of nanophase iron oxides/oxyhydroxides in Mars soil. The mode of formation of these nanophase iron oxides on Mars is still unknown. It is puzzling that despite the long period of time since aqueous weathering took place on Mars, they have not developed from their transitory stage to well-crystallized end-members. The possibility is suggested that these phases represent a continuously on-going, extremely slow weathering process.

Clathrate Hydrates can be formed under high vacuum conditions by annealing vapor-deposited amorphous ices of the appropriate composition. When astrophysically significant H2O:CH3OH ices are deposited and annealed, Type II Clathrate Hydrates are formed which can hold up to 6 mole % large guest molecules such as methanol and 12 mole % small guest molecules such as CO2 and CO. The solid state transformation of amorphous mixed molecular ice into crystalline clathrate hydrate and its sublimation at higher temperatures may serve to explain heretofore anomalous mechanical and gas release properties observed in cometary ices and laboratory ice analog experiments.

Food preference and utilization experiments with Sitophilus oryzae (L.) used 17 corn genotypes, including 11 inbreds with waxy (wx, wx) and opaque 2 (Op2) conversions and 6 commercial hybrids. Measurements made on each genotype on number of adults attracted and the number of eggs laid indicated that higher numbers of rice weevils were attracted to the hybrids than to inbred lines. Measurements in utilization of food were days required to reach pupation, amount of food consumed, feces excreted, and pupal weight. Efficiency of conversion of ingested food (ECI), approximate digestibility (AD), and efficiency of conversion of digested food (ECD) were calculated indices. The weevils were sensitive to the various genotypes. Time required to pupation was longer in normal genotypes if compared with those having either the Op2 gene or the wx gene. The wx gene reduced the food consumed and feces excreted, and ECI and ECD were lower in genotypes with Op2 but higher when the wx gene was present. Food consumed and fecal weight were higher for the hybrids compared with the inbred lines, but the ECI and ECD indices were lower.

SUMMARY A series of equations is presented through which thin-film X-ray microanalytical data may be characterized statistically. Test statistics based on the Gaussian distribution are then presented, together with examples of the use and evaluation of an empirically derived Mg/Ca working curve.

Protein. starch. fat. sucrose. glucose. and fructose contents were analyzed in 22 com genotypes and correlated with food utiliz'ltion panlmeters and indices determined on developing rice weevil. Sirophillls 01}'zae (L.), reared on each com genotype. The larval period was reduced and heavier pupae developed from com with higher glucose content. Increascd levels of prOiein reduced amount of food consumed and increased food utilization efficiency. Larv,le reared on pelletized. germ less kernels required a longer time to reach pupation, had lower pupal weights and lower food utilization efficiency than did larvae reared on pellctized whole kernels. However. mortality was similar in both treatments indicating that nutrients found in the germ were not essential. A homogenous distribution of nutrients in the food reduced larval developmcnt time and increased food utilization efficiency. To better understand the relationships of an insect pest to its host. several arcas of study including nutrition must be considered. There is relatively little information about the influence of major groups of nutrients found in com kernels on the development of the rice weevil, SilOphilus ory:ae (L.). Singh and McCain (1963) found that field infestation and number of offspring were positively correlated with sugar and starch contents of com hybrids but neither fat nor protein seemed to affect com susceptibility or de­ velopment of the rice weevil (RW). Singh et al. (1972) found that protein content was not related to resistance. but Dobie (1977) observed that protein content was neg­ atively correlated with a susceptibility index. McCain and Eden (1965) indicated that susceptibility of com inbred lines to RW attack. expressed as number of live adults after a 2-month infestation. was positively cor­ related with the percentage of reducing sugars. but not with total sugar content. Rhine and Staples (1968) suggested that percentage of amylose found in the starch portion influences sus~ ceptibility of com to rice weevil. Chippendale (1972) concluded that adult weevils survived in diets containing ca. 70% cereal starches, dextrins. amylopectin. or gly­ cogen, but died prematurely when the diets contained 70% amylose. cellulose. inulin. or mono- or disacchar­ ides. Carbohydrates that did not allow survival acted as feeding deterrents without causing digestive enzymatic lesions. Richards (1944) reported that germ tissue is toxic to Ist-instar larvae of the rice weevil. Schoonhoven et al. (1974) showed that additions of small amounts of extra germ tissue to pellets made of ground com increased the number of progeny and weight and shortened the de

Kernels of corn inbred lines A619 (susceptible) and B37 (resistant) were extracted sequentially with chloroform, hexane, and ethanol. The extracts and the residue were tested for chemosensory reactions of Sitophilus oryzae (L.). The ethanol extract of A619 incorporated into pellets composed of laundry starch stimulated oviposition and attracted weevils in an olfactometer for a 1-h period, whereas the chlorofonn extract of both lines induced weevil aggregation in starch pellets for 1 week. The hexane extract and the residue of both lines did not cause a noticeable response by the weevils.

A simple hand-held grinding fixture is discussed which can produce microtome mounts of hard materials, oriented interfaces, and powders embedded in a 5/16-in plastic rod. The device has been used for the ultramicrotomy of meteorite samples, 10-50 micron interplanetary dust particles, and thin films on plastic. Results are presented for a layer lattice silicate from the Murchison carbonaceous chondrite, illustrating the resolution and structural detail that can be obtained with the method.

Columnals of Neocrinus blakei, a modern species of stalked crinoid, were studied using a variety of analytical techniques. Analyses of the magnesium calcite of the crinoid stereom using powder X-ray diffraction and electron microprobe analysis yield a composition of Ca 88Mg 12C03. Scanning transmission electron microscopy (STEM) microanalytical data indicate that Mg incorporation into the calcite structure of the crinoid stereom is random and homogeneous to at least the 20 nm level. There appear to be no variations in composition at this level either within or between structural entities of the crinoid columnal stereom. TEM reveals a heterogeneity of contrast which may be due to incorporation of organic material or some other substance which is non-crystalline in character. Single-crystal X-ray diffraction data indicate that the individual skeletal plates are single crystals which yield diffuse and imperfect X-ray reflections due to a mosaic structure. Subsequent selected area electron diffraction (SAD) photographs via TEM, using various sizes of SAD apertures, indicate that the crystallites making up the mosaic structure are (order of magnitude) about 1.0 micrometer in size. The presence of mosaic structure in the single crystal skeletal elements may at least in part explain the lack of cleavage in fracture surfaces of echinoderm skeletal material. Based on these data, as well as data from skeletal elements of other deep water, stalked crinoids, we feel that these results may be applicable to crinoids in general, at least those existing in relatively constant temperature environments. The single-crystal nature of crinoid high magnesium calcite, and its remarkable homogeneity of composition suggest that a large "vital effect" (i. e., biologic control of skeletal deposition) mediates the mineralization process.

A recent focus of marine carbonate research is the determination of secular variations in paleo-ocean chemistry through the study of modern and ancient marine cements. By studying the major and minor element chemistry of marine carbonate cements, it is in principle possible to infer the chemical composition of the marine waters from which such cements precipitated. However, since most inorganically precipitated phases in the marine environment are metastable, they commonly undergo chemical and mineralogic stabilization (i.e., diagenesis) in the post-depositional environment. Such processes at low temperature require solution-reprecipitation reactions involving extraneous and generally non-marine fluids, and typically lead to a loss of the chemical information contained in the original marine carbonate cements.

A number of workers have described instrument modifications designed to reduce systems peaks obtained in an analytical electron microscope during EDS analyses (1-4). These procedures, while effective, have suffered from one or all of the following limitations: 1) the physical modifications to the column limit the versatility of the instrument in other modes of operation (for example, low magnification scanning may be prohibited); 2) hole counts invariably comprise a large enough fraction of the sample spectrum that they must be subtracted from the spectrum prior to quantitation; and 3) analysis for elements such as Cu or Fe, which are present in the near specimen environment, is either impaired or precluded. We have found that the JEOL JEM-100CX can be modified to produce ultra-clean X-ray spectra that suffer from none of the above limitations.

Interplanetary Dust Particles (IDPs) are a relatively new class of extraterrestrial materials which are collected by high-flying aircraft in the stratosphere. The particles, ∼1.0-50 μm in size, enter the earth's atmosphere at ballistic velocities, but are sufficiently small to be decelerated without burning up. IDPs commonly have solar elemental abundances, and are thoughfto have undergone very little differentiation since the formation of the solar system. While these materials are called “particles,” they are in fact aggregates of a variety of mineral phases, glass, and carbonaceous material. Grains within IDPs commonly range from a few microns to a few tens of nanometers. The extraterrestrial origin of IDPs has been established by the discovery of solar flare tracks in some mineral grains, and recent D/H isotopic ratios recorded from individual particles. The source and formational history of the particles is a topic of active research. At present, the primary means of screening and classifying IDPs is Scanning Electron Microscopy, although a variety of electron microbeam and X-ray techniques is used for subsequent analysis.

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.