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Blake, D. F.

Publications and source records attributed to Blake, D. F..

At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS2012

Definitive Mineralogy from the Mars Science Laboratory Chemin Instrument

The Mars Science Laboratory (MSL) rover will land in Gale Crater on Mars in August 2012. The planned landing site is an alluvial fan near the base of the crater's central mound. Orbital remote sensing of this 5 km high mound indicates the presence of hydrated sulfates, interstratified with smectite and hematite-bearing layers. Minerals formed in an aqueous environment are of particular interest given that water is a fundamental ingredient of living systems and that MSL's prime science objective is to investigate martian habitability.

Yen, A. S.↗
NASA NTRS2011

A Terrestrial Analogue from Spitsbergen (Svalbard, Norway) for the Comanche Carbonate at Gusev Crater, Mars

Carbonate occurs at the Comanche outcrops in Gusev Crater on the basis of analyses made by the Mars Exploration Rover Spirit [1]. Taken together, mineralogical data from Spirit's Moessbauer (MB) and Mini-TES spectrometer and chemical data from the APXS spectrometer show that Comanche carbonate has an Mg-Fe-rich bulk chemical composition, is present at high concentrations, and is distributed throughout the outcrop and not just at the MB and APXS analysis location. The granular outcrop texture and the observation that it appears to be resistant to weathering compared with surrounding material [1] imply that the carbonate may be present as a cement. A hydrothermal origin for the Comanche carbonate was inferred by analogy with laboratory experiments and with a carbonate occurrence within the Bockfjord volcanic complex on the island Spitsbergen (Svalbard, Norway) [1]. The laboratory carbonates, synthesized by precipitation from hydrothermal solutions, have (MB) parameters and average bulk chemical compositions that are characteristic of Comanche carbonate. The connection to Comanche carbonate is only through chemical data for certain occurrences of Spitsbergen carbonates. In fact, the common average bulk chemical composition for these Spitsbergen carbonates, the synthetic carbonates, the Comanche carbonate, and also the carbonate globules found in martian meteorite ALH84001 is a chemical constraint consistent with a hydrothermal formation process for all the carbonates [e.g., 1-3]. We develop here a link between MB data for the Comanche carbonate from MER and MB data for certain Spitsbergen carbonate occurrences from laboratory measurements. We also obtained visible and near- IR spectra on Spitsbergen carbonates for comparison with martian carbonate detections made on the basis of CRISM spectral data, e.g., in Nili Fossae [4].

Morris, Richard V.↗
NASA NTRS2011

Detection Limit of Smectite by Chemin IV Laboratory Instrument: Preliminary Implications for Chemin on the Mars Science Laboratory Mission

The CheMin instrument on the Mars Science Laboratory (MSL) is an miniature X-ray diffraction (XRD) and X-ray fluorescence (XRF) instrument capable of detecting the mineralogical and elemental compositions of rocks, outcrops and soils on the surface of Mars. CheMin uses a microfocus-source Co X-ray tube, a transmission sample cell, and an energy-discriminating X-ray sensitive CCD to produce simultaneous 2-D XRD patterns and energy-dispersive X-ray histograms from powdered samples. CRISM and OMEGA have identified the presence of phyllosilicates at several locations on Mars including the four candidate MSL landing sites. The objective of this study was to conduct preliminary studies to determine the CheMin detection limit of smectite in a smectite/olivine mixed mineral system.

Archilles, Cherie↗
NASA NTRS2011

Cryogenic Origin for Mars Analog Carbonates in the Bockfjord Volcanic Complex Svalbard (Norway)

The Sverrefjell and Sigurdfjell eruptive centers in the Bockfjord Volcanic Complex (BVC) on Svalbard (Norway) formed by subglacial eruptions ca. 1 Ma ago. These eruptive centers carry ubiquitous magnesian carbonate deposits including dolomitemagnesite globules similar to those in the Martian meteorite ALH84001. Carbonates in mantle xenoliths are dominated by ALH84001 type carbonate globules that formed during quenching of CO2-rich mantle fluids. Lava hosted carbonates include ALH84001 type carbonate globules occurring throughout lava vesicles and microfractures and massive carbonate deposits associated with vertical volcanic vents. Massive carbonates include < or equal 5 cm thick magnesite deposits protruding downwards into clear blue ice within volcanic vents and carbonate cemented lava breccias associated with volcanic vents. Carbonate cements comprise layered deposits of calcite, dolomite, huntite, magnesite and aragonite associated with ALH84001 type carbonate globules lining lava vesicles. Combined Mossbauer, XRD and VNIR data show that breccia carbonate cements at Sverrefjell are analog to Comanche carbonates at Gusev crater.

Amundsen, H. E. F.↗
NASA NTRS2011

Field Characterization of the Mineralogy and Organic Chemistry of Carbonates from the 2010 Arctic Mars Analog Svalbard Expedition by Evolved Gas Analysis

The 2010 Arctic Mars Analog Svalbard Expedition (AMASE) investigated two geologic settings using methodologies and techniques being developed or considered for future Mars missions, such as the Mars Science Laboratory (MSL), ExoMars, and Mars Sample Return. The Sample Analysis at Mars (SAM) [1] instrument suite, which will be on MSL, consists of a quadrupole mass spectrometer (QMS), a gas chromatograph (GC), and a tunable laser mass spectrometer (TLS); all will be applied to analyze gases created by pyrolysis of samples. During AMASE, a Hiden Evolved Gas Analysis-Mass Spectrometer (EGA-MS) system represented the EGA-MS capability of SAM. Another MSL instrument, CheMin, will use x-ray diffraction (XRD) and x-ray fluorescence (XRF) to perform quantitative mineralogical characterization of samples [e.g., 2]. Field-portable versions of CheMin were used during AMASE. AMASE 2010 focused on two sites that represented biotic and abiotic analogs. The abiotic site was the basaltic Sigurdfjell vent complex, which contains Mars-analog carbonate cements including carbonate globules which are excellent analogs for the globules in the ALH84001 martian meteorite [e.g., 3, 4]. The biotic site was the Knorringfjell fossil methane seep, which featured carbonates precipitated in a methane-supported chemosynthetic community [5]. This contribution focuses on EGA-MS analyses of samples from each site, with mineralogy comparisons to CheMin team results. The results give insight into organic content and organic-mineral associations, as well as some constraints on the minerals present.

McAdam, A. C.↗
NASA NTRS2011

Carbonate Cements from the Sverrefjell and Sigurdfjell Volcanoes, Svalbard Norway: Analogs for Martian Carbonates

The Sverrefjell and Sigurdfjell volcanic complexes erupted at ~1Ma on Svalbard, Norway. Sverrefjell is a cone of cinders, pillow lavas and dikes; Sigurdfjell is elongate in outcrop and may represent a fissure eruption [1]. The lavas of both volcanos were volatile rich. The volcanos erupted under ice and were subsequently dissected by glaciation (glacial eratics are present on most of Sverrefjell, even on its summit). Eruption beneath an ice sheet is inferred, based on the presence of pillow lavas from near sea level to ~1000 m above sea level. Sverrefjell contains the largest fraction of ultramafic xenoliths of any volcanic complex in the world, in places accounting for as much as 50% of the volume of the outcrop. The Sverrefjell and Sigurdfell volcanos contain carbonate cements of several varieties: (1) Amundsen [2] reported Mg-Fe-rich carbonate in sub-mm globules in basalts and ultramafic xenoliths from the volcanos. These globules are the best terrestrial analogs to the carbonate globules in the Mars meteorite ALH84001 [3]. (2) Thick (1-3 cm) coatings of carbonate cement drape the walls of vertical volcanic pipes or conduits on the flanks and near the present summit of Sverrefjell. Similar occurrences are found on Sigurdfjell. (3) Breccia-filled pipes or vents occur on Sverrefjell and Siggurdfjell in which the breccia fragments are cemented by carbonate. The fragments themselves commonly contain carbonate globules similar to those found in the basalts and ultramafic xenoliths.

Blake, D. F.↗
NASA NTRS2010

Evolved Gas Analysis and X-Ray Diffraction of Carbonate Samples from the 2009 Arctic Mars Analog Svalbard Expedition: Implications for Mineralogical Inferences from the Mars Science Laboratory

The 2009 Arctic Mars Analog Svalbard Expedition (AMASE) investigated several geologic settings using methodologies and techniques being developed or considered for future Mars missions, such as the Mars Science Laboratory (MSL), ExoMars, and Mars Sample Return (MSR). AMASE-related research comprises both analyses conducted during the expedition and further analyses of collected samples using laboratory facilities at a variety of institutions. The Sample Analysis at Mars (SAM) instrument suite, which will be part of the Analytical Laboratory on MSL, consists of a quadrupole mass spectrometer (QMS), a gas chromatograph (GC), and a tunable laser spectrometer (TLS). An Evolved Gas Analysis Mass Spectrometer (EGA-MS) was used during AMASE to represent part of the capabilities of SAM. The other instrument included in the MSL Analytical Laboratory is CheMin, which uses X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF) to perform quantitative mineralogical characterization of samples. Field-portable versions of CheMin were used during the AMASE 2009. Here, we discuss the preliminary interpretation of EGA and XRD analyses of selected AMASE carbonate samples and implications for mineralogical interpretations from MSL. Though CheMin will be the primary mineralogical tool on MSL, SAM EGA could be used to support XRD identifications or indicate the presence of volatile-bearing minerals which may be near or below XRD detection limits. Data collected with instruments in the field and in comparable laboratory setups (e.g., the SAM breadboard) will be discussed.

McAdam, A. C.↗
NASA NTRS2010

Test and Delivery of the Chemin Mineralogical Instrument for Mars Science Laboratory

The CheMin mineralogical instrument on MSL will return quantitative powder X-ray diffraction data (XRD) and qualitative X-ray fluorescence data (XRF; 14<Z<92) from scooped soil samples and drilled rock powders collected on the Mars surface. The geometry of the source, sample, and detector is shown. A transmission geometry was chosen so that diffracted intensities in the low-20 region (5-15 deg), important for phyllosilicate identification, could be detected.

Blake, D. F.↗
NASA NTRS2005

CheMin: A Definitive Mineralogy Instrument in the Analytical Laboratory of the Mars Science Laboratory (MSL '09)

An important goal of the Mars Science Laboratory (MSL 09) mission is the determination of definitive mineralogy and chemical composition. CheMin is a miniature X-ray diffraction/X-ray fluorescence (XRD/XRF) instrument that has been chosen for the analytical laboratory of MSL. CheMin utilizes a miniature microfocus source cobalt X-ray tube, a transmission sample cell and an energy-discriminating X-ray sensitive CCD to produce simultaneous 2-D X-ray diffraction patterns and X-ray fluorescence spectra from powdered or crushed samples. A diagrammatic view of the instrument is shown.

Blake, D. F.↗
NASA NTRS2005

Pods: a Powder Delivery System for Mars In-situ Organic, Mineralogic and Isotopic Analysis Instruments

Many Mars in situ instruments require fine-grained high-fidelity samples of rocks or soil. Included are instruments for the determination of mineralogy as well as organic and isotopic chemistry. Powder can be obtained as a primary objective of a sample collection system (e.g., by collecting powder as a surface is abraded by a rotary abrasion tool (RAT)), or as a secondary objective (e.g, by collecting drill powder as a core is drilled). In the latter case, a properly designed system could be used to monitor drilling in real time as well as to deliver powder to analytical instruments which would perform complementary analyses to those later performed on the intact core. In addition, once a core or other sample is collected, a system that could transfer intelligently collected subsamples of power from the intact core to a suite of analytical instruments would be highly desirable. We have conceptualized, developed and tested a breadboard Powder Delivery System (PoDS) intended to satisfy the collection, processing and distribution requirements of powder samples for Mars in-situ mineralogic, organic and isotopic measurement instruments.

Saha, C. P.↗
NASA NTRS2004

Astrobiological Significance of Definitive Mineralogical Analysis of Martian Surface Samples Using the CheMin XRD/XRF Instrument

The search for evidence of habitability, or of extant or extinct life on Mars, will initially be a search for evidence of past or present conditions supportive of life. The three key requirements for the emergence of life are thought to be liquid water; a suitable energy source; and chemical building blocks. CheMin is a miniaturized XRD/XRF (X-Ray diffraction / X-ray fluorescence) instrument which has been developed for definitive mineralogic analysis of soils and rocks on the Martian surface. The CheMin instrument can provide information that is highly relevant to each of these habitability requirements as summarized below.

Feldman, S. M.↗
NASA NTRS2004

Evaluation of Rock Powdering Methods to Obtain Fine-grained Samples for CHEMIN, a Combined XRD/XRF Instrument

A miniature XRD/XRF (X-ray diffraction / X-ray fluorescence) instrument, CHEMIN, is currently being developed for definitive mineralogic analysis of soils and rocks on Mars. One of the technical issues that must be addressed to enable remote XRD analysis is how best to obtain a representative sample powder for analysis. For powder XRD analyses, it is beneficial to have a fine-grained sample to reduce preferred orientation effects and to provide a statistically significant number of crystallites to the X-ray beam. Although a two-dimensional detector as used in the CHEMIN instrument will produce good results even with poorly prepared powder, the quality of the data will improve and the time required for data collection will be reduced if the sample is fine-grained and randomly oriented. A variety of methods have been proposed for XRD sample preparation. Chipera et al. presented grain size distributions and XRD results from powders generated with an Ultrasonic/Sonic Driller/Corer (USDC) currently being developed at JPL. The USDC was shown to be an effective instrument for sampling rock to produce powder suitable for XRD. In this paper, we compare powder prepared using the USDC with powder obtained with a miniaturized rock crusher developed at JPL and with powder obtained with a rotary tungsten carbide bit to powders obtained from a laboratory bench-scale Retsch mill (provides benchmark mineralogical data). These comparisons will allow assessment of the suitability of these methods for analysis by an XRD/XRF instrument such as CHEMIN.

Chipera, S. J.↗
NASA NTRS2004

Definitive Mineralogical Analysis of Mars Analog Rocks Using the CheMin XRD/XRF Instrument

Mineral identification is a critical component of Mars Astrobiological missions. Chemical or elemental data alone are not definitive because a single elemental or chemical composition or even a single bonding type can represent a range of substances or mineral assemblages. Minerals are defined as unique structural and compositional phases that occur naturally. There are about 15,000 minerals that have been described on Earth, all uniquely identifiable via diffraction methods. There are likely many minerals yet undiscovered on Earth, and likewise on Mars. If an unknown phase is identified on Mars, it can be fully characterized by structural (X-ray Diffraction, XRD) and elemental analysis (X-ray Fluorescence, XRF) without recourse to other data because XRD relies on the principles of atomic arrangement for its determinations. XRD is the principal means of identification and characterization of minerals on Earth.

Blake, D. F.↗
NASA NTRS2003

Use of an Ultrasonic/Sonic Driller/Corer to Obtain Sample Powder for CHEMIN, a Combined XRD/XRF Instrument

A miniature CHEMIN XRD/XRF (X-Ray Diffraction/X-Ray Fluourescence) instrument is currently being developed for definitive mineralogic analysis of soils and rocks on Mars. One of the technical issues that must be addressed in order to enable XRD analysis on an extraterrestrial body is how best to obtain a representative sample powder for analysis. For XRD powder diffraction analyses, it is beneficial to have a fine-grained sample to reduce preferred orientation effects and to provide a statistically significant number of crystallites to the X-ray beam. Although a 2-dimensional detector as used in the CHEMIN instrument will produce good results with poorly prepared powders, the quality of the data will improve if the sample is fine-grained and randomly oriented. An Ultrasonic/Sonic Driller/Corer (USDC) currently being developed at JPL is an effective mechanism of sampling rock to produce cores and powdered cuttings. It requires low axial load (< 5N) and thus offers significant advantages for operation from lightweight platforms and in low gravity environments. The USDC is lightweight (<0.5kg), and can be driven at low power (<5W) using duty cycling. It consists of an actuator with a piezoelectric stack, ultrasonic horn, free-mass, and drill bit. The stack is driven with a 20 kHz AC voltage at resonance. The strain generated by the piezoelectric is amplified by the horn by a factor of up to 10 times the displacement amplitude. The tip impacts the free-mass and drives it into the drill bit in a hammering action. The free-mass rebounds to interact with the horn tip leading to a cyclic rebound at frequencies in the range of 60-1000 Hz. It does not require lubricants, drilling fluid or bit sharpening and it has the potential to operate at high and low temperatures using a suitable choice of piezoelectric material. To assess whether the powder from an ultrasonic drill would be adequate for analyses by an XRD/XRF spectrometer such as CHEMIN, powders obtained from the JPL ultrasonic drill were analyzed and the results were compared to carefully prepared powders obtained using a laboratory bench scale Retsch mill.

Chipera, S. J.↗