ORCID Profile
0000-0002-7412-3535
Current Organisations
University of Western Ontario
,
CSIRO
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Publisher: Elsevier BV
Date: 02-2019
Publisher: Oxford University Press (OUP)
Date: 08-2019
Publisher: Elsevier BV
Date: 2019
Publisher: Elsevier BV
Date: 10-2019
Publisher: CSIRO
Date: 2019
Publisher: Mary Ann Liebert Inc
Date: 04-2022
Abstract: The Mars 2020 Perseverance rover landed on February 18, 2021, and has started ground operations. The ExoMars
Publisher: Oxford University Press (OUP)
Date: 08-2014
Publisher: Elsevier BV
Date: 03-2023
Publisher: American Geophysical Union (AGU)
Date: 10-2018
DOI: 10.1029/2018JE005600
Publisher: Cambridge University Press (CUP)
Date: 17-12-2013
DOI: 10.1017/S1473550413000402
Abstract: Spring and evaporite deposits are considered two of the most promising environments for past habitability on Mars and preservation of biosignatures. Manitoba, Canada hosts the East German Creek (EGC) hypersaline spring complex, and the post impact evaporite gypsum beds of the Lake St. Martin (LSM) impact. The EGC complex has microbial mats, sediments, algae and biofabrics, while endolithic communities are ubiquitous in the LSM gypsum beds. These communities are spectrally detectable based largely on the presence of a chlorophyll absorption band at 670 nm however, the robustness of this feature under Martian surface conditions was unclear. Biological and biology-bearing s les from EGC and LSM were exposed to conditions similar to the surface of present day Mars (high UV flux, 100 mbar, anoxic, CO 2 rich) for up to 44 days, and preservation of the 670 nm chlorophyll feature and chlorophyll red-edge was observed. A decrease in band depth of the 670 nm band ranging from ∼16 to 80% resulted, with correlations seen in the degree of preservation and the spatial proximity of s les to the spring mound and mineral shielding effects. The spectra were deconvolved to Mars Exploration Rover (MER) Pancam and Mars Science Laboratory (MSL) Mastcam science filter bandpasses to investigate the detectability of the 670 nm feature and to compare with common mineral features. The red-edge and 670 nm feature associated with chlorophyll can be distinguished from the spectra of minerals with features below ∼1000 nm, such as hematite and jarosite. However, distinguishing goethite from s les with the chlorophyll feature is more problematic, and quantitative interpretation using band depth data makes little distinction between iron oxyhydroxides and the 670 nm chlorophyll feature. The chlorophyll spectral feature is observable in both Pancam and Mastcam, and we propose that of the proposed EXOMARS Pancam filters, the PHYLL filter is best suited for its detection.
Publisher: Elsevier BV
Date: 11-2021
Publisher: Mary Ann Liebert Inc
Date: 03-2020
Abstract: No instrument capable of direct life detection has been included on a mission payload to Mars since NASA's Viking missions in the 1970s. This prevents us from discovering whether life is or ever was present on Mars. DNA is an ideal target biosignature since it is unambiguous, nonspecific, and readily detectable with nanopore sequencing. Here, we present a proof-of-concept utilization of the Oxford Nanopore Technologies (ONT) MinION sequencer for direct life detection and show how it can complement results from established space mission instruments. We used nanopore sequencing data from the MinION to detect and characterize the microbial life in a set of paleochannels near Hanksville, UT, with supporting data from X-ray diffraction, reflectance spectroscopy, Raman spectroscopy, and Life Detector Chip (LDChip) microarray immunoassay analyses. These paleochannels are analogs to martian sinuous ridges. The MinION-generated metagenomes reveal a rich microbial community dominated by bacteria and containing radioresistant, psychrophilic, and halophilic taxa. With spectral data and LDChip immunoassays, these metagenomes were linked to the surrounding Mars analog environment and potential metabolisms (
Publisher: Springer Science and Business Media LLC
Date: 11-03-2020
DOI: 10.1007/S11004-020-09859-0
Abstract: Manually interpreting multivariate drill hole data is very time-consuming, and different geologists will produce different results due to the subjective nature of geological interpretation. Automated or semi-automated interpretation of numerical drill hole data is required to reduce time and subjectivity of this process. However, results from machine learning algorithms applied to drill holes, without reference to spatial information, typically result in numerous small-scale units. These small-scale units result not only from the presence of very small rock units, which may be below the scale of interest, but also from misclassification. A novel method is proposed that uses the continuous wavelet transform to identify geological boundaries and uses wavelet coefficients to indicate boundary strength. The wavelet coefficient is a useful measure of boundary strength because it reflects both wavelength and litude of features in the signal. This means that boundary strength is an indicator of the apparent thickness of geological units and the amount of change occurring at each geological boundary. For multivariate data, boundaries from multiple variables are combined and multiscale domains are calculated using the combined boundary strengths. The method is demonstrated using multi-element geochemical data from mineral exploration drill holes. The method is fast, reduces misclassification, provides a choice of scales of interpretation and results in hierarchical classification for large scales where domains may contain more than one rock type.
Publisher: Geological Society of London
Date: 24-02-2023
Abstract: This study examines how laser-induced breakdown spectroscopy (LIBS) data collected using a downhole deployable LIBS prototype for geochemical analysis in a fashion that imitates downhole deployment may be used for mineralogical investigations. Two chemically and mineralogically practically identical felsic rocks, namely granite and microgranite, are used to assess the effects of rock texture on mineral classification and high-resolution SEM-TIMA (scanning electron microscope coupled with TESCAN's integrated mineral analyser) mineral maps are used to reveal mineralogical composition of each LIBS ablation crater. Additionally, in order to extend the LIBS application for fast mineralogical studies to a greenfield scenario (i.e. no previous knowledge) a clustering methodology is presented for mineralogical classification from LIBS data. Results indicate that most LIBS spot analyses s le mineral mixtures, 91.2 and 100% for granite and microgranite, respectively, which challenges mineralogical classification, particularly for fine-grained rocks. Positive identification and classification of minerals of slightly different compositions relative to the bulk rock (i.e. fluorite and biotite in granitic rocks) demonstrates how minerals or minerals groups of distinct and interesting chemical compositions (e.g. sulfides or oxides in silicate-dominated rocks) can be rapidly recognized in a mineral exploration scenario. Strategies for overcoming mineral mixture issues are presented and recommendations are given for effective workflows for mineralogical analysis using LIBS data in different mineral exploration stages. Supplementary material : Complete LIBS analyses for granite and microgranite s les (Appendix A) modal mineralogy results for each LIBS ablation crater based on TIMA analysis (Appendix B) and TIMA mineral maps for granite and microgranite s les are available at 0.6084/m9.figshare.c.6444482
Publisher: Society of Economic Geologists
Date: 05-2021
DOI: 10.5382/ECONGEO.4790
Abstract: Recently discovered Au in boulder conglomerate between the Mesoarchean West Pilbara superterrane basement and the overlying volcano-sedimentary stratigraphy of the Neoarchean Fortescue Group in Western Australia has renewed comparisons with the Witwatersrand conglomerate Au deposits in South Africa. As such, this has reignited the question of the Pilbara and Kaapvaal cratons being linked as part of the postulated Vaalbara continent during the Archean. However, little is known about the origin of the Pilbara conglomerate Au and its host conglomerates, as they are hitherto unstudied, and their formation and/or source is uncertain. Here we present a detailed study on the textures, composition, and sedimentology of one newly discovered Pilbara conglomerate Au deposit at the base of the Neoarchean Fortescue Group in the northwestern Pilbara craton. The Pilbara conglomerate Au occurrences are characteristically Ag-bearing but Hg-poor polycrystalline discoid masses that are overgrown by Au-poor chloritic halos, which are further enveloped by a hydrothermal alteration halo of disseminated Au within chlorite. Both the discoids and the auriferous chlorite halo are Ag bearing, with up to ~9 wt % Ag, consistent with a hydrothermal (orogenic) origin. The discoids do not display any physical or chemical evidence for sedimentary transport thus, their formation (placer versus hydrothermal) remains unclear. However, the position of the Au in the conglomerate, limited to the basal section of the conglomerate, is difficult to account for in a purely hydrothermal deposit model. We argue the Pilbara conglomerate Au represents a modified placer deposit from a primary orogenic Au source, with surface evidence for sedimentation removed by partial dissolution during later hydrothermal alteration in the host conglomerate and the crystalline basement. While the basal Fortescue Group conglomerate Au shares commonalities with the time equivalent (& ~2.7 Ga) Venterspost Conglomerate Formation, which overlies the Witwatersrand Supergroup, inconsistencies remain, with different Au chemistries and tectonic, magmatic, sedimentary, and metamorphic-metallogenic histories of the Pilbara and Kaapvaal cratons prior to deposition of the & .7 Ga conglomerate sequences. This collectively indicates the drivers of Au metallogenesis and ultimate Au deposition in conglomerate facies were fundamentally different in the Pilbara and Kaapvaal cratons.
Publisher: American Geophysical Union (AGU)
Date: 04-06-2019
DOI: 10.1029/2018GL081339
Publisher: Elsevier BV
Date: 06-2013
Publisher: Cambridge University Press (CUP)
Date: 18-09-2014
DOI: 10.1017/S1473550414000378
Abstract: There is increasing evidence that Mars may have once been a habitable environment. Gypsum is targeted in the search for Martian biosignatures because it can host extensive cryptoendolithic communities in extreme terrestrial environments and is widespread on Mars. In this study the viability of using different spectroscopy-based techniques to identify the presence of gypsum endolithic communities was investigated by analysing various cryptoendoliths collected from the Lake St. Martin impact crater (LSM), a Mars analogue site found in Manitoba, Canada. Concurrently, the cryptoendolithic microbial community structure present was also analysed to aid in assigning spectroscopic features to microbial community members. Two main morphologies of endolithic communities were collected from gypsum deposits at LSM: true cryptoendolithic communities and annular deposits on partially buried boulders and cobbles cm below the soil surface. Endolithic communities were found to be visibly present only in gypsum with a high degree of translucency and could occur as deep as 3 cm below the exterior surface. The bacterial community was dominated by a phylum ( Chloroflexi ) that has not been previously observed in gypsum endoliths. The exterior surfaces of gypsum boulders and cobbles are devoid of spectroscopic features attributable to organic molecules and detectable by reflectance, Raman, or ultraviolet-induced fluorescence spectroscopies. However, exposed interior surfaces show unique endolithic signatures detectable by each spectroscopic technique. This indicates that cryptoendolithic communities can be detected via spectroscopy-based techniques, provided they are either partially or fully exposed and enough photon–target interactions occur to enable detection.
Publisher: Elsevier BV
Date: 2019
Publisher: Elsevier BV
Date: 06-2018
Publisher: Informa UK Limited
Date: 11-11-2019
Publisher: Elsevier BV
Date: 05-2015
Publisher: MDPI AG
Date: 26-03-2021
DOI: 10.3390/MIN11040347
Abstract: Reflectance spectroscopy allows cost-effective and rapid mineral characterisation, addressing mineral exploration and mining challenges. Shortwave (SWIR), mid (MIR) and thermal (TIR) infrared reflectance spectra are collected in a wide range of environments and scales, with instrumentation ranging from spaceborne, airborne, field and drill core sensors to IR microscopy. However, interpretation of reflectance spectra is, due to the abundance of potential vibrational modes in mineral assemblages, non-trivial and requires a thorough understanding of the potential factors contributing to the reflectance spectra. In order to close the gap between understanding mineral-diagnostic absorption features and efficient interpretation of reflectance spectra, an up-to-date overview of major vibrational modes of rock-forming minerals in the SWIR, MIR and TIR is provided. A series of scripts are proposed that allow the extraction of the relative intensity or wavelength position of single absorption and other mineral-diagnostic features. Binary discrimination diagrams can assist in rapidly evaluating mineral assemblages, and relative abundance and chemical composition of key vector minerals, in hydrothermal ore deposits. The aim of this contribution is to make geologically relevant information more easily extractable from reflectance spectra, enabling the mineral resources and geoscience communities to realise the full potential of hyperspectral sensing technologies.
Publisher: Elsevier BV
Date: 04-2021
Location: Australia
No related grants have been discovered for Jessica Stromberg.