Dina M Bower

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Dina M Bower

  • Research Scientist
  • 301.614.5786
  • NASA/GSFC
  • Mail Code: 699
  • Greenbelt , MD 20771
  • Employer: UNIV OF MARYLAND COLLEGE PARK
  • Research Interests

    Life detection strategies for ancient Earth rocks and on Mars; biosignatures on icy worlds; the interactions between microbes and minerals and how these interactions shape the geologic landscape

    Dr. Dina M. Bower uses micro Raman spectroscopy to geochemically characterize a variety of geologic materials. She is especially interested in establishing or ruling out biosignatures in Mars-analog ancient Earth rocks that contain microfossils or carbonaceous materials, in meteorites, and experimentally induced biominerals. She also applies her expertise to identifying biosignatures in Europa analogues and in the characterization of lunar materials. She is currently working on a Raman geothermometer for carbonaceous materials. Dr. Bower is also very inetersted in the use of noble gas isotope mass spectrometry to complement other geochemical techniques for life detection. 

    Current Projects

    Discerning the origins of lunar deposits from Apollo 16 using micro Raman spectroscopy

    Raman spectroscopy is a powerful and versatile non-destructive analytical technique that provides compositional and contextual information on mineral phases for a wide variety of geologic samples including lunar rocks. Lunar rocks are composed of a limited suite of minerals, and being able to detect the subtle differences between mineral phases is essential in understaning their origins. The goal ultimately is to correlate the compositions and ages of lunar rocks to understand the impact history of the Earth-Moon system in conjunction with noble gas dating techniques.

    The identification of micro Raman biosignatures in Europa analogues

    The ability to identify biosignatures in icy environments is essential for upcoming life detection missions on Europa or similar worlds. Micro Raman spectroscopy can be used to quickly and efficiently identify minerals, salts, and organics in ice, but much work is yet to be done to establish a solid database of Raman signatures specific to these environments. 

    Geochemical characterization of ancient terrestrial hydrothermal deposits to establish biosignatures for exoplanetary life detection

    With micro Raman spectroscopy we can characterize the quartz fabrics, macromolecular carbon, mineral phases, and fluid inclusions in ancient chert deposits to identify biosignatures using Raman spectral signatures. Raman spectroscopy is a non-destructive technique that can identify several different chemical specires in one scan. It is thought that many ancient cherts on Earth contain biosignatures indicative of the earliest forms of life as far back as ~3.5 Ga. These signatures are detectable using Raman spectroscopy, and we can apply the data collected from Earth rocks to those we will analyze for upcoming Mars missions.

    To corroberate the Raman results, I also analyze the same chert samples using electron microprobe. This allows us to better understand the sources of some of the more ambiguous mineral assemblages and macromolecular carbon that appear to be indicative of life but are actually abiotic.

    Constraining the origins of biosignatures in hydrothermal deposits using noble gas isotopes

    Terrestrial hydrothermal deposits such as cherts contain some of the earliest signatures of life on Earth, yet the origins of some of these signatures is still ambiguous. Cherts are formed from silica-rich fluids in which gases become trapped. In Earth's oldest rocks (≥ 3.5 Ga), there can be several generations of chert veins that contain possible biosignatures which can confuse the true age of the chert deposits themselves. Noble gases retain their isotopic signatures for billions of years, and their signatures can be indicative of atmospheric conditions and original fluid composition. We couple geochemical data from micro Raman spectroscopy and electron microprobe with the isotopic signatures of Ar, Kr, and Xe to better constrain the emplacement of the chert forming fluids and their possible biosignature components.

    Publications

    Refereed

    Bower, D. M., D. R. Hummer, and A. Steele. 2017. "AN EXPERIMENTAL LOOK AT THE TAPHONOMY OF CYANOBACTERIAL MATS IN SILICICLASTIC SEDIMENTS." PALAIOS, 32 (12): 725-738 [10.2110/palo.2017.016]

    Bower, D. M., A. Steele, M. D. Fries, O. R. Green, and J. F. Lindsay. 2016. " Raman imaging spectroscopy of a putative microfossil from the ~3.46 Ga Apex Chert: insights from quartz crystal orientation ." Astrobiology, 16 (2): [10.1089/ast.2014.1207]

    Bower, D. M., D. R. Hummer, A. Kyono, and A. Steele. 2015. "The co-evolution of Fe-,Ti-oxides and other microbially induced mineral precipitates in sandy sediments: understanding the role of cyanobacteria in weathering and early diagenesis ." Journal of Sedimentary Research, 85: 1213-1227 [10.2110/jsr.2015.76]

    Szponar, N., W. J. Brazelton, M. O. Schrenk, et al. D. M. Bower, A. Steele, and P. L. Morrill. 2013. "Geochemistry of a continental site of serpentinization in the Tablelands Ophiolite, Gros Morne National Park: a Mars analogue ." Icarus, 224: 286-296 [10.1016/j.icarus.2012.07.004]

    Bower, D. M., A. Steele, M. D. Fries, and L. Kater. 2013. "Micro Raman spectroscopic investigations of carbonaceous material in microfossils and meteorites: improving the use of G- and D-band parameters for life detection." Astrobiology, 13 (1): 103-113 [10.1089/ast.2012.0865]

    Bower, D. M. 2011. "Micro Raman spectroscopic investigations of laminae associated mineral assemblages in 2.9 Ga sandstones of the Pongola Supergroup, South Africa." Journal of Raman Spectroscopy, 42 (8): 1626-1633 [10.1002/jrs.2903]

    Noffke, N., N. Beukes, D. M. Bower, R. M. Hazen, and D. J. Swift. 2008. "An actualistic perspective into Archean worlds – (cyano-)bacterially induced sedimentary structures in the siliciclastic Nhlazatse Section, 2.9 Ga Pongola Supergroup, South Africa." Geobiology, 6: 5-20 [10.1111/j.1472-4669.2007.00118.x]

    Non-Refereed

    Lewis, J. M., J. L. Eigenbrode, A. C. Mcadam, et al. S. Andrejkovicova, C. Knudson, G. Wong, M. Millan, C. Freissinet, C. Szopa, X. Li, and D. M. Bower. 2017. "The Preservation and Detection of Organic Matter within Jarosite." AGU Fall Meeting [Full Text (Link)]

    Positions/Employment

    1/2009 - 1/2012

    NAI Postdoctoral Program Fellow

    Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC

    Experimental and observational approaches to using minerals as biosignatures in ancient
    rocks: perfecting analytical techniques to identify life on early Earth and on other planets
     

    1/2012 - 6/2012

    Adjunct Professor

    Tidewater Community College, Norfolk, VA

    Oceanography, Natural Sciences Department

    Education

    PhD Ocean, Earth, and Atmospheric Science 2003-2008
    Old Dominion University, Norfolk, Virginia
    Dissertation: Microtextures of cyanobacterial mats in siliciclastic sedimentary environments (modern & ancient): applications to the search for life on Mars

    B.Sc. Oceanography / B.A. Geology 1998-2003
    Richard Stockton College of New Jersey, Pomona, New Jersey
     

    Talks, Presentations and Posters

    Invited

    The Variability of Biosignatures Through Geologic Time

    9 / 12 / 2017

    The identification of biosignatures in ancient rocks is hampered by the effects of geologic time. Micro Raman spectroscopy can be used to characterize morpholgical and chemical features in terrestrial cherts. Some of the oldest cherts are useful as analogs for siliceous lithologies on Mars. The older the cherts on Earth, however, the more ambiguous the signatures indicative of life become. The implications of these difficulties and the recent advances in understaning are discussed with an emphasis on applications to upcoming Mars rover missions.

    Applications of Micro Raman Spectroscopy: Microfossils and Astrobiology

    4 / 5 / 2016

    Micro Raman imaging is essential in the study of microfossils in the context of astrobiology, because the technique is non-destructive, spectral signatures are useful in identifying compounds that are relevant to biologic processes, and the imaging capabilities establish spatial relationships and make it easy to put the identified features in context.

     

    WITec Micro Raman Imaging Workshop, Rutgers University, Newark, NJ  April 5-6, 2016

    Understanding the origins of possible cyanobacterial biosignatures in ancient siliciclastic rocks

     

    Geological Society of Washington

    9 / 30 / 2015

    Cyanobacteria are well-known architects of modern microbial mats and likely thrived on Earth as far back as the Archean. Siliciclastic sediments in particular are home to a wide variety of microbial mat communities, yet traces of their ancestors in ancient siliciclastic rocks are difficult to detect.The results suggest that over time, the collection of morphological, mineralogical, and carbonaceous features that formed at the end of incubation experiments could ultimately create the laminations characteristic of microbial mats found in ancient sandstones.

    Incubation studies of cyanobacteria and natural ilmenites (FeTiO3): understanding the co-evolution of microbes and minerals during diagenesis

     

    Geochemistry Seminar Series, Geology Department, University of Maryland, College Park

    9 / 2011

    The contribution of benthic mat-building cyanobacteria to weathering and compositional changes to minerals in sandy sediments is not typically considered. To understand the influence of cyanobacterial mats on mineral weathering, incubation exepriments using abiotic controls for comparison were done using ilmenite sands and ilmenite enriched beach sands over 5 months at 3 temperature steps. A large variety of mineral phases formed only in the samples incubated with cyanobacteria, suggesting that cyanobacteria do indeed play an important role in sediment weathering.

    Investigations of the nature and provenance of mineral and carbonaceous material in fossiliferous cherts: revisiting the 1.9 Ga Gunflint Formation

     

    Geological Society of Washington

    2 / 17 / 2010

    The Gunflint cherts represent an ancient microbial ecosystem as evidenced by the ample microfossils and carbon signatures. Using micro Raman spectroscopy, the composition and spatial relationships of microfossils and other features can be readily attained. In the Gunflint samples, carbon is not limited to the microfossils, but is also found within the quartz grain interstices. The results suggest a post-depositional emplacement of some of the carbon in theses samples, possibly by hydrothermal overprint.

    Teaching Experience

    Adjunct Instructor:

    Tidewater Community College, Norfolk, VA (2012) Introduction to Oceanography

    Old Dominion University, Norfolk, VA (2008) Introduction to Oceanography, Physical Geology

     

    Teaching Assistant:

    Old Dominion University, Norfolk, VA (2007) Paleontology

    Richard Stockton University, Pomona, NJ (2001-2003) Physical Geology, Chemical Oceanography

    Professional Societies

    Geochemical Society, 2010 - Present
    Geological Society of America, 2000 - Present
    American Geophysical Union, 1999 - Present

    Awards

    NASA Astrobiology Institute Postdoctoral Fellowship 2009-2012
    National Prominence Award, Old Dominion University, Norfolk, Virginia 2003-2004
    NSF Research Experience for Undergraduates, Shannon Point Marine Center, WA 2002
    Distinguished Student Fellowship Award, Richard Stockton College of New Jersey
     

    Selected Public Outreach

    Chair, Gordon Research Seminar on Geobiology 1 / 2013 - 1 / 2013
    https://www.grc.org/programs.aspx?id=15607

    The Future of Geobiology: Perspectives from Graduate and Postdoctoral Research

    The focus of this meeting is to explore the diverse and dynamic field of geobiology . The discussions and presentations will address these main themes:

    • microbial structures in ancient and modern settings
    • taphonomy and micropaleontology
    • biomineralization and the co-evolution of minerals and microbes
    • life detection for applications to early life on Earth and other planets
    • integrating geobiobiology into interdisciplinary research and academic programs

    Special Experience

    Field Work I have been a part of:

    Pongola Supergroup, South Africa (2005) : mapping, sketching, videography, and sample collection of sandstones. 

    Fisherman's Island, Virginia (2005-2007): transects of tidal flats, collection of microbial mat samples.

    Biosignatures in Ancient Rocks Workshop, Ontario, Canada (2007): collection of Gunflint cherts and samples from rock successions related to the Sudbury impact event

    Gros Morne National Park, Newfoundland, Canada (2009,2010): "clean" field methods to asses life in serpentinzed ophiolite sequence; CHEMin portable XRD field analysis of carbonates.

    White Sands, New Mexico (2009): collection of microbial mats and sulfates in gypsum dunes; Delta Nu portable Raman (785 nm) field analysis of sulfates.

    Saskatchewan, Canada (2009): sample collection of halophilic microbial mats.

    Mono Lake, California (2010): videographer for rover drill prototype

    Publications

    Refereed

    Bower, D. M., D. R. Hummer, and A. Steele. 2017. "AN EXPERIMENTAL LOOK AT THE TAPHONOMY OF CYANOBACTERIAL MATS IN SILICICLASTIC SEDIMENTS." PALAIOS 32 (12): 725-738 [10.2110/palo.2017.016]

    Bower, D. M., A. Steele, M. D. Fries, O. R. Green, and J. F. Lindsay. 2016. " Raman imaging spectroscopy of a putative microfossil from the ~3.46 Ga Apex Chert: insights from quartz crystal orientation ." Astrobiology 16 (2): [10.1089/ast.2014.1207]

    Bower, D. M., D. R. Hummer, A. Kyono, and A. Steele. 2015. "The co-evolution of Fe-,Ti-oxides and other microbially induced mineral precipitates in sandy sediments: understanding the role of cyanobacteria in weathering and early diagenesis ." Journal of Sedimentary Research 85 1213-1227 [10.2110/jsr.2015.76]

    Szponar, N., W. J. Brazelton, M. O. Schrenk, et al. D. M. Bower, A. Steele, and P. L. Morrill. 2013. "Geochemistry of a continental site of serpentinization in the Tablelands Ophiolite, Gros Morne National Park: a Mars analogue ." Icarus 224 286-296 [10.1016/j.icarus.2012.07.004]

    Bower, D. M., A. Steele, M. D. Fries, and L. Kater. 2013. "Micro Raman spectroscopic investigations of carbonaceous material in microfossils and meteorites: improving the use of G- and D-band parameters for life detection." Astrobiology 13 (1): 103-113 [10.1089/ast.2012.0865]

    Bower, D. M. 2011. "Micro Raman spectroscopic investigations of laminae associated mineral assemblages in 2.9 Ga sandstones of the Pongola Supergroup, South Africa." Journal of Raman Spectroscopy 42 (8): 1626-1633 [10.1002/jrs.2903]

    Noffke, N., N. Beukes, D. M. Bower, R. M. Hazen, and D. J. Swift. 2008. "An actualistic perspective into Archean worlds – (cyano-)bacterially induced sedimentary structures in the siliciclastic Nhlazatse Section, 2.9 Ga Pongola Supergroup, South Africa." Geobiology 6 5-20 [10.1111/j.1472-4669.2007.00118.x]

    Non-Refereed

    Lewis, J. M., J. L. Eigenbrode, A. C. Mcadam, et al. S. Andrejkovicova, C. Knudson, G. Wong, M. Millan, C. Freissinet, C. Szopa, X. Li, and D. M. Bower. 2017. "The Preservation and Detection of Organic Matter within Jarosite." AGU Fall Meeting [Full Text (Link)]

                                                                                                                                                                                            
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