Bonnie Teece

My Mission

I apply context-driven multi-technique approaches to increase reliability in interpreting biosignatures in my research. I also use my background as a first-generation, working-class academic to inform values-driven equitable approaches to education and outreach.

Biomolecules from Fossilized Hot Spring Sinters: Implications for the Search for Life on Mars

Bronwyn L. Teece, Simon C. George, Tara Djokic, Kathleen A. Campbell,
Steven W. Ruff, and Martin J. Van Kranendonk

Astrobiology, 20(4)
DOI: 10.1089/ast.2018.2018

Hot spring environments are commonly dominated by silica sinters that precipitate by the rapid cooling of silica-saturated fluids and the activity of microbial communities. However, the potential for preservation of organic traces of life in silica sinters back through time is not well understood. This is important for the exploration of early life on Earth and possibly Mars. Most previous studies have focused on physical preservation in samples <900 years old, with only a few focused on organic biomarkers. In this study, we investigate the organic geochemistry of hot spring samples from El Tatio, Chile and the Taupo Volcanic Zone, with ages varying from modern to ~9.4 ka. Results show that all samples contain opaline silica and contain hydrocarbons that are indicative of a cyanobacterial origin. A ~3 ka recrystallized, quartz-bearing sample also contains traces of cyanobacterial biomarkers. No aromatic compounds were detected in a ~9.4 ka opal-A sample or in a modern sinter breccia sample. All other samples contain naphthalene, with one sample also containing other polyaromatic hydrocarbons. These aromatic hydrocarbons have a thermally mature distribution that is perhaps reflective of geothermal fluids migrating from deep, rather than surface, reservoirs. These data show that hot spring sinters can preserve biomolecules from the local microbial community, and that crystallinity rather than age may be the determining factor in their preservation. This research provides support for the exploration for biomolecules in opaline silica deposits on Mars.

Mars Rover Techniques and Lower/Middle
Cambrian Microbialites from South Australia:
Construction, Biofacies, and Biogeochemistry

Bronwyn L. Teece, Simon C. George, Oluwatoosin Bunmi A. Agbaje,
Sarah M. Jacquet, and Glenn A. Brock

Astrobiology, 20(5)
DOI: 10.1089/ast.2019.2110

The Perseverance rover (Mars 2020) is equipped with an instrumental and analytical payload capable of identifying a broad range of organic molecules in geological samples. To determine the efficacy of these analytical techniques in recognizing important ecological and environmental signals in the rock record, this study utilized analogous equipment, including gas chromatography/mass spectrometry, Raman spectroscopy, X-ray fluorescence (XRF), Fourier transform infrared spectroscopy, along with macroscopic and petrographic observations, to examine early-middle Cambrian microbialites from the Arrowie Basin, South Australia. Morphological and petrographic observations of these carbonate successions reveal evidence of hypersaline-restricted environments. Microbialites have undergone moderate diagenesis, as supported by XRF data that show mineral assemblages, including celestine and the illitization of smectite. Raman spectral data, carbon preference indices of ∼1, and the methylphenanthrene index place the samples in the prehnite/pumpellyite metamorphic facies. Pristane and phytane are the only biomarkers that were detected in the least thermally mature samples. This research demonstrates a multitechnique approach that can yield significant geological, depositional, paleobiological, and diagenetic information that has important implications for planning future astrobiological exploration.

Using laser micropyrolysis to assess potential relationships between Cambrian tommotiids and organophosphatic brachiopods

Bronwyn L. Teece, Glenn A. Brock, John R. Paterson, Christian B. Skovsted,
Lars E. Holmer, Simon C. George

Journal of Analytical and Applied Pyrolysis, 158
DOI: 10.1016/j.jaap.2021.105277

Laser micropyrolysis gas chromatography-mass spectrometry enables researchers to selectively obtain chemical information about the organic matter in specific parts of a variety of specimens, such as coals and fossils, in order to elucidate chemical composition. This paper briefly reviews the history of this type of pyrolysis and examines whether the technique can be used to isolate and recover biogeochemical signatures directly from the mineralised organophosphatic sclerites of Cambrian tommotiids—a group of enigmatic lophotrochozoans—and potentially related organophosphatic brachiopods. We analysed specimens of two tommotiids (Micrina etheridgei and Dailyatia sp.) and the paterinate brachiopod Askepasma toddense from the lower Cambrian of South Australia. Pyrolysate hydrocarbons from the sclerites of these species were detected and compared. Results indicate that A. toddense is more chemically complex than either of the two tommotiid taxa, but that M. etheridgei is compositionally more similar to A. toddense. Importantly, this study has demonstrated that laser micropyrolysis gas chromatography-mass spectrometry of Cambrian organophosphatic small shelly fossils yields detectable pyrolysates that have geochemical significance. It will be analytically possible and useful in the future to apply this technique to a larger sample set to elucidate deep time biogeochemical homologies, and to test intra-shell heterogeneity.

Making it happen: An experience of using Earth Observation-based research outputs for engaging high school students in novel technologies for sustainable agriculture

Bronwyn L. Teece, Graciela Metternicht, Antonio Gnassi, Francesco Vuolo, Oscar Rosario Belifore

Geographical Education, 34

Educational policy and management emphasise the role of science (e.g., earth science, geography) as a fundamental aspect of societal
advance, but student enrolments at universities in these disciplines remain low. This commentary explores ways to foster more collaboration between university academics and high school teachers to implement STEM-related curriculum through hands-on exploration of novel earth observation (EO) technologies. To this end, we develop project-based learning activities through the Copernicus applications and services for low impact agriculture in Australia (COALA) project, an international venture of eleven partners seeking to promote the adoption of products and services for sustainable agriculture in Australia, underpinned by satellite technology from the European Copernicus programme. We reflect on our experiences developing project-based learning activities, and particularly on the benefits and obstacles we faced.

Computational Infrared Spectroscopy of 958 Phosphorus-Bearing Molecules

Juan C. Zapata Trujillo, Anna-Maree Syme, Keiran N. Rowell, Brendan P. Burns, Ebubekir S. Clark, Maire N. Gorman, Lorrie S. D. Jacob, Panayioti Kapodistrias, David J. Kedziora, Felix A. R. Lempriere, Chris Medcraft, Jensen O’Sullivan, Evan G. Robertson, Georgia G. Soares, Luke Steller, Bronwyn L. Teece, Chenoa D. Tremblay, Clara Sousa-Silva and Laura K. McKemmish

Frontiers in Astronomy and Space Sciences, 8
DOI: 10.3389/fspas.2021.639068

Phosphine is now well-established as a biosignature, which has risen to prominence with its recent tentative detection on Venus. To follow up this discovery and related future exoplanet biosignature detections, it is important to spectroscopically detect the presence of phosphorus-bearing atmospheric molecules that could be involved in the chemical networks producing, destroying or reacting with phosphine. We start by enumerating phosphorus-bearing molecules (P-molecules) that could potentially be detected spectroscopically in planetary atmospheres and collecting all available spectral data. Gaseous P-molecules are rare, with speciation information scarce. Very few molecules have high accuracy spectral data from experiment or theory; instead, the best current spectral data was obtained using a high-throughput computational algorithm, RASCALL, relying on functional group theory to efficiently produce approximate spectral data for arbitrary molecules based on their component functional groups. Here, we present a high-throughput approach utilizing established computational quantum chemistry methods (CQC) to produce a database of approximate infrared spectra for 958 P-molecules. These data are of interest for astronomy and astrochemistry (importantly identifying potential ambiguities in molecular assignments), improving RASCALL’s underlying data, big data spectral analysis and future machine learning applications. However, this data will probably not be sufficiently accurate for secure experimental detections of specific molecules within complex gaseous mixtures in laboratory or astronomy settings. We chose the strongly performing harmonic ωB97X-D/def2-SVPD model chemistry for all molecules and test the more sophisticated and time-consuming GVPT2 anharmonic model chemistry for 250 smaller molecules. Limitations to our automated approach, particularly for the less robust GVPT2 method, are considered along with pathways to future improvements. Our CQC calculations significantly improve on existing RASCALL data by providing quantitative intensities, new data in the fingerprint region (crucial for molecular identification) and higher frequency regions (overtones, combination bands), and improved data for fundamental transitions based on the specific chemical environment. As the spectroscopy of most P-molecules have never been studied outside RASCALL and this approach, the new data in this paper is the most accurate spectral data available for most P-molecules and represent a significant advance in the understanding of the spectroscopic behavior of these molecules.