Education: B.A.Geological Sciences/Secondary Education, SUNY Geneseo Current Project (PhD Dissertation):
Subglacial Volcanic Outflood Deposits in Iceland: Comparisons to Chasma Boreale, Mars
I. Introduction
Large, sediment laden flood events known as jokulhlaups are generated through melting induced by the onset of volcanic activity beneath the Vatnajokull ice sheet in southeastern Iceland (Gudmundsson and Bjornsson, 1991). Several eruptive events situated beneath the Vatnajokull ice sheet have occurred during historical times at Grimsvotn, Kverkfjoll, Baroarbunga, Esjufjoll, and Oraefajokul volcanic centers. During these events, melting of the basal portion of the ice sheet generates an active hydrothermal lake. As melting continues, and the lake volume increases, the overlying pressure from the weight of the ice sheet is overcome. This series of events leads to the release of liquid water, sediment, rafted ice, and presumably, microbial life representing a broad range of subglacial aqueous environments, ranging from hydrothermal to interstitial ice-brine. Currently, several aerially extensive alluvial outflood deposits, form accreted shorelines (sandur plains) south of the Vatnajokull ice sheet. These distinctive, channelized deposits consist of well-sorted, fragmented volcanic glass (hyaloclastites), that exhibit a wide variety of fluvial sedimentary structures and bedding styles. The goal of the terrestrial analog part of the study is to characterize the sedimentology and geomorphology of Icelandic sandurs through detailed (total station) mapping of sedimentary facies and topographic profiling (from previously acquired laser altimetry). In the laboratory, sandur materials will be examined for evidence of microbial alteration fabrics, or fossil biosignatures preserved in volcanic glasses, comparable to those that have been described from glassy basaltic pillow rinds in the deep sea (Thorseth et al. 2001).
The findings of the analog study will be used to test a previously proposed model for the origin of deposits located in the northern polar region of Mars by jokulhlaup style outflooding (Clifford, 1987; Fishbaugh and Head, 2002). The deposits of interest occur on the floor of Chasma Boreale, a large trough-like feature that differs in scale and orientation from other troughs on the northern polar cap (Figure 1). The removal of ice cap material during a
volcanically triggered flood event has been a suggested formational mechanism for the Chasma Boreale feature (Fishbaugh and Head, 2002). Assuming the validity of this scenario, subglacial volcanic lake environments would likely have existed beneath the martian north polar ice cap prior to the formation of Chasma Boreale and the subsequent deposition of the outflood deposit. Such hydrothermal environments would be ideal habitats for ancient or current microbial life on Mars (Farmer 1998; 2000). Ice rich, volcanoclastic materials deposited by the outflood of such a lake could potentially contain biosignatures. This would make sites within the Chasma Boreale system ideal for future life detection missions to Mars that are likely to occur after 2015.
M.S. Geological Sciences, SUNY Buffalo
PHD (candidate) Geological Sciences, Arizona State University
Short Curriculum Vitae
II. Methods
The proposed research is subdivided two major phases. The first phase will be conducted from 2005 though 2006 and will include the analysis of remotely sensed data from Mars and Iceland. The second phase will involve fieldwork in Iceland during the summer of 2006 (and potentially 2007).
During the first phase, we will utilize terrestrial altimeter data acquired during previously-funded NASA investigations in Iceland (PI: James Garvin, NASA Headquarters). This data will be convolved to Mars Orbiter Laser Altimeter (MOLA) resolution to make adequate morphologic comparisons. Thickness, width, and slope measurements will be obtained from several transects across the length and width of the deposits. These measurements can be used in conjunction with empirical models to estimate volumetric flow rates and other fluvial transport properties.
Potential similarities between Icelandic deposits and those at Chasma Boreale will be assessed using a variety of available terrestrial and martian image data sources. For the Icelandic deposits we intend to obtain VIS/NIR and Thermal IR ASTER images at resolutions of 15 – 90 m/pixel to describe their overall aerial extent, morphology, and composition. We also intend to describe the morphology (e.g. sinuosity) of braided fluvial channels that formed within the deposits subsequent to jokulhlaup depositional events. Images for Mars will be obtained from Viking Orbiter (VO), Mars Orbiting Camera (MOC), and Thermal Emission Imaging System (THEMIS) data sources. As an example of image comparison, figure 2 displays a sinuous channel of unknown formational origin visible within the Chasma Boreale deposit. This THEMIS image was recently released and can be used to describe similarities and differences in channel morphology between the deposits. High resolution (2-5 m/pixel) MOC images will help to visualize sedimentation patterns on the walls and floor of Chasma Boreale. MOC images will also be utilized to distinguish crater morphologies suggestive of near-surface ground ice. We intend to work with Dr. Ron Greeley’s planetary group to obtain High Resolution Stereo Camera (HRSC) images of Chasma Boreale from Mars Express. These images can provide a unique oblique 3-D view. We also hope to obtain assistance from Dr. Phil Christensen’s THEMIS group to target areas within and surrounding Chasma Boreale.
The second phase of this project is the Iceland field work component. The major goal of the field work will be to characterize the sedimentology and smaller scale morphology of the jokulhlaup deposits with an emphasis on describing the depositional features (sedimentary textures and structures) indicative of high flow regime, large volume, sediment rich flows. Our field work will focus on the distribution of bed form structures (dunes, mega-ripples and ripples), spatial variations in grain size, and sediment composition. Meso-scale features will be documented from outcrops (cut banks of incised channels) and micro-scale features will be studied in thin sections of hand samples. Mineralogy will be confirmed using Powder X-ray Diffraction methods and lab spectroscopy. As noted, icelandic jokulhlaup deposits are enriched in fragmented basaltic glass. However, the presence of hydrothermally-altered materials, as well as primary hydrothermal mineral phases, is also likely, given that a hydrothermal lake was the source of the flow (Gudmundsson and Bjornsson, 1991). Using ENVI and other remote sensing tools, we will look for such hydrothermal mineral signatures in both high-resolution infrared remote sensing data and through a ground truth analysis of samples collected in the field. The abundance of volcanic glass in these sediments also has important implications for the development of microbial alteration textures that have been widely reported from volcanic glasses in deep sea basalts (Thorseth et al. 2001). We will explore for evidence of similar textures in the icelandic hyaloclastites of these environments using a combination of light and electron microscopy and biological fluorescence staining methods.
III. Conclusion
In this research we will examine alternative hypotheses for the formation of Chasma Boreale, a large canyon system in the North polar cap of Mars with a particular emphasis on testing the sub-glacial volcanism-jokulhlaup hypothesis for its origin. We will approach this through a detailed analysis of remote sensing data for Mars previously obtained by Mars Global Surveyor and Odyssey, as well as new data to be acquired by Mars Reconnaissance Orbiter to be launched later this year. If the deposits in Chasma Boreale formed by volcanic outflooding, the water that carried the sediments to the surface, would have also carried any subsurface biosignatures present and sequestered them in ground ice as the flood waters percolated into the canyon floor. Because the analog terrestrial deposits are comprised of primarily fragmented volcanic glass and potentially a hydrothermal alteration mineral assemblage, the potential exists for both mineral signatures for habitable subsurface environments as well as microbial biosignatures, as either alteration fabrics in glass, or as organic materials entrapped in ground ice. Our overarching goal will be to evaluate the potential for past/present habitable environments within the Chasma Boreale region, the potential for biosignature capture and preservation and the importance of this site for future astrobiological missions to explore for biosignatures of past or present life.
IV. References
Clifford, S., 1987, Polar basal melting on Mars, Journal of Geophysical Research, v. 92, 9135 – 9152
Farmer, J.D. 1999. Exploring for evidence of Martian life in polar ice deposits. Eos Trans AGU, 80 (46), F-70.
Farmer, J.D. 2000. Hydrothermal systems: Doorways to early biosphere evolution. GSA Today 10: 1-9.
Add at least one more recent review ref on bioalteration fabrics in basaltic glasses.
Fishbaugh, K.E., and Head, J.W., 2002, Chasma Boreale, Mars: Topographic characterization from Mars Orbiter Laser Altimeter data and implications for mechanisms of formation, Journal of Geophysical Research, v. 107, no. E3, 10,1029
Gudmundsson, M.T., Bjornsson, H., 1991, Eruptions in Grimsvotn, Vatnajokull, Iceland, 1934-1991, Jokull, no. 41, 21 – 43.
Thorseth, I.H., Torsvik, T., Torsvik, V., Daae, F.L., Pedersen, R.B., Keldysh-98 Scientific Party, 2001, Diversity of life in ocean floor basalt, Earth and Planetary Science Letters, v. 194, 31-37
More Images of Chasma Boreale:
High Resolution Stereo Camera (HRSC) image of the northern scaprs of Chasma Boreale
Courtesy of the Mars Express team
HRSC image zoomed in on the northern scarp of Chasma Boreale
HRSC image of volcanic cones near the martian north pole
A zoomed in HRSC image of a near north pole volcanic cone
Publications:
Warner, N.H., and Gregg, T.K.P., 2003, Evolved lavas on Mars? Observations from southwest Arsia Mons and Sabancaya volcano, Peru, Journal of Geophysical Research, v. 108 (E-10), 5112.
Gregg T.K.P., Bulmer, M., and Anderson, S.W., Warner, N.H., Goudy, C.L., McColley, S., and Turner, I., 2002. Three types of crust: Inferred emplacement rates and styles of a megablocky flow field surrounding Sabancaya volcano, Peru; EOS, Transactions of the American Geophysical Union, v. 83, Abstract V72C-05.
Warner, N.H., and Gregg, T.K.P., 2002, Lava flow field southwest of Arsia Mons: Estimates and comparisons of rheologic properties, 33rd Lunar and Planetary Science Conference, Abstract, 1324.
Gregg, T.K.P., Bulmer, M.H., Warner, N.H., 2002, Lava flow field at Sabancaya volcano, Peru: Analog for extraterrestrial lavas?, 33rd Lunar and Planetary Science Conference, Abstract, 1565.
Gregg, T.K.P., Bulmer, M.H., Warner, N.H., 2001, Lava flow fields on Earth and Mars: Scales of comparison, AGU Fall Meeting Abstract, v. 82, n. 47, 705.
Warner, N.H., Gregg, T.K.P., and Bulmer, M.H., 2001, Textured lava flows on Earth, Mars, and Venus, 32nd Lunar and Planetary Science Conference, Abstract, 1693.
Over, D.J., Hopkins, T.L., Obligado, A., Rotondo, K.A., Spaziani, A.L., and Warner, N., 2001, Sequences in Upper Devonian black shale of the Appalachian Basin: Middlesex, Rhinestreet, and the Frasnian-Famennian boundary interval, Geological Society of America, Abstracts with Programs, v. 33(1), A17.
Awards:
Geological Sciences Alumni Scholarship, SUNY Geneseo, 1997
National Science Foundation Fellowship Funding Award, SUNY Geneseo, 1999
Graduation with honors, Geological Sciences, SUNY Geneseo, 2000
Best Student Paper (Dwornik) Award, 33rd Lunar and Planetary Science Conference, 2002
ASU NASA Space Grant Award, 2005
Class Papers:
Estimated eruption conditions for a lunar sinuous rille: Valles Schroteri
The thermal and atmospheric evolution of Mars and the role of flood volcanism
Ignimbrites in Amazonis Planitia, Mars
Mapping a silicic volcanic terrain in the Superstition Mountains, AZ using TIMS
Note: All papers lack figures due to website size constraints. For relevant figures contanct me at Nicholas.Warner@asu.edu
Links:
Malin Space Science Systems Mars Orbiting Camera image database
Arizona State University Thermal Emission Imaging System site