JSG_Logo
Tim Goudge

Research Interests:

Open-Basin Lake on Mars
Topography overlain on an image of a hydrologically open paleolake basin on Mars. Arrows show inferred flow direction.

My research focuses on the evolution of planetary landscapes, and how this is controlled by both geochemical and mechanical surface processes. The primary tool I use for my research is high-spatial-resolution remote sensing data, such as images, topography, and visible to near-infrared (VNIR) reflectance spectroscopy. By combining these complementary datasets, I work towards understanding how surface processes are recorded in the topography, mineralogy, and sedimentary rock record of Mars, as well as Earth and other planetary bodies.

Broad questions that drive my research include: How can the landscape-scale perspective of remote sensing data be leveraged for studying the record of planetary surface processes? What effects have the distinct boundary conditions on Mars, as compared to Earth, had on controlling surface processes? What signals of the ancient surface environment of Mars (e.g., climate, hydrologic cycle) are recorded by its rock record? How did the martian surface environment evolve through time?


Research Topics:

Remotely Characterizing Planetary Surface Processes:

Remote sensing data provide a unique, landscape-scale view of planetary surfaces, which allows one to ask complementary questions to those addressed by field, theoretical, experimental, and modeling work. I am in interested using remote sensing to study the geomorphic and mineralogic signatures of both ancient and modern surface processes on Mars, Earth, and other planetary bodies. Much of my work has focused on understanding the evolution of martian paleolake basins and their associated sedimentary deposits, which provide a record of the surface environmental conditions during their lifetime of activity.

Paleolake Basins on Mars
Paleolakes on Mars
Different types of paleolake basins on Mars: open-basin lake in heavily degraded crater (left), closed-basin lake in heavily degraded crater (middle), and closed-basin lake in less degraded crater (right). My work has shown that the paleolake record of early Mars is dominated by open-basin lakes. This provides a broad constraint on the past martian hydrologic cycle: water inputs (e.g., surface runoff) were sufficiently larger than water losses (e.g., evaporation) to allow the vast majority of valley-fed lake basins on early Mars to fill completely and overtop (see also Goudge et al., Geology, 2016).

 

Relevant Publications and Abstracts:

Goudge, T. A., C. I. Fassett, J. W. Head, J. F. Mustard, and K. L. Aureli (2016), Insights into surface runoff on early Mars from paleolake basin morphology and stratigraphy, Geology, 44, 419-422, DOI: 10.1130/G37734.1.

Levy, J. S., T. A. Goudge, J. W. Head, and C. I. Fassett (2017), Candidate volcanic and impact-induced ice depressions on Mars, Icarus, 285, 185-194, DOI: 10.1016/j.icarus.2016.10.021.

Goudge, T. A., K. L. Aureli, J. W. Head, C. I. Fassett, and J. F. Mustard (2015), Classification and analysis of candidate impact crater-hosted closed-basin lakes on Mars, Icarus, 260, 346-367, DOI: 10.1016/j.icarus.2015.07.026.

Goudge, T. A., J. F. Mustard, J. W. Head, C. I. Fassett, and S. M. Wiseman (2015), Assessing the mineralogy of the watershed and fan deposits of the Jezero crater paleolake system, Mars, J. Geophys. Res., 120, 775-808, DOI: 10.1002/2014JE004782.

Dickson, J. L., J. W. Head, T. A. Goudge, and L. Barbieri (2015), Recent climate cycles on Mars: Stratigraphic relationships between multiple generations of gullies and the latitude dependent mantle, Icarus, 252, 83-94, DOI: 10.1016/j.icarus.2014.12.035.

Goudge, T. A., J. F. Mustard, J. W. Head, and C. I. Fassett (2012), Constraints on the history of open-basin lakes on Mars from the composition and timing of volcanic resurfacing, J. Geophys. Res., 117, E00J21, DOI: 10.1029/2012JE004115.

Goudge, T. A., J. W. Head, J. F. Mustard, and C. I. Fassett (2012), An analysis of open-basin lake deposits on Mars: Evidence for the nature of associated lacustrine deposits and post-lacustrine modification processes, Icarus, 219, 211–229, DOI: 10.1016/j.icarus.2012.02.027.


Sedimentary Deposits on Mars and Terrestrial Analogs:

Mars has an abundance of sedimentary deposits, which provide a record of past surface processes and environments, and how these evolved through time and space. Active research involves detailed analyses of the stratigraphic architecture of sedimentary deposits on Mars to further understand the paleoenvironmental signals these rocks preserve. This work employs high-resolution digital elevation models (DEMs) and orthorectified images to analyze exposed stratal geometries, similar to studies of sedimentary outcrops on the Earth (albeit at orbital as opposed to in person resolution). I am also working to integrate VNIR hyperspectral image data into these analyses to understand martian sedimentary mineralogy in the context of stratigraphic position.

I am also interested in understanding how processes of sediment transport, deposition, and accumulation may have differed on Mars compared with Earth due to distinct boundary conditions (e.g., basin topography provided by impact craters). This work involves a combination of techniques including numerical modeling, laboratory experiments, and field-based studies of terrestrial analogs.

Jezero Delta Exposed Layering
Exposed Layers in Jezero Crater Delta
Exposed layering within the Jezero crater western delta deposit. Top figure shows an overview image, and bottom figure shows a perspective view (look direction shown by white 'V' in top figure) using stereo-derived topography produced with the NASA Ames Stereo Pipeline. My past research has shown that the stratigraphic architecture and spatial distribution of clay minerals (i.e., phyllosilicates) within this deposit are indicative of a deltaic depositional environment (see also Goudge et al., EPSL, 2017). I am also involved with the proposal of the Jezero crater paleolake basin as a potential landing site for the Mars 2020 Rover. At the last landing site workshop (2/2017) it was ranked as one of the final three candidate sites undergoing further consideration.

 

Relevant Publications and Abstracts:

Goudge, T. A., R. E. Milliken, J. W. Head, J. F. Mustard, and C. I. Fassett (2017), Sedimentological evidence for a deltaic origin of the western fan deposit in Jezero crater, Mars and implications for future exploration, Earth Planet. Sci. Lett., 458, 357-365, DOI: 10.1016/j.epsl.2016.10.056.

Goudge, T. A., D. Mohrig, B. T. Cardenas, C. M. Hughes, J. S. Levy, and C. I. Fassett (2016), Sedimentology of the Jezero crater western fan deposit: 2. Secular changes in the style of channelization, 47th Lunar and Planetary Science Conference, Abstract 1656. PDF here.

Goudge, T. A., K. L. Aureli, J. W. Head, C. I. Fassett, and J. F. Mustard (2015), Classification and analysis of candidate impact crater-hosted closed-basin lakes on Mars, Icarus, 260, 346-367, DOI: 10.1016/j.icarus.2015.07.026.

Goudge, T. A., J. F. Mustard, J. W. Head, C. I. Fassett, and S. M. Wiseman (2015), Assessing the mineralogy of the watershed and fan deposits of the Jezero crater paleolake system, Mars, J. Geophys. Res., 120, 775-808, DOI: 10.1002/2014JE004782.

Goudge, T. A., J. W. Head, J. F. Mustard, and C. I. Fassett (2012), An analysis of open-basin lake deposits on Mars: Evidence for the nature of associated lacustrine deposits and post-lacustrine modification processes, Icarus, 219, 211–229, DOI: 10.1016/j.icarus.2012.02.027.


Spectroscopy of Terrestrial Sedimentary Deposits:

VNIR reflectance spectroscopy is a useful tool for laboratory analysis of samples, and I am particularly interested in using this technique to understand the mineralogy of terrestrial sedimentary deposits, both modern and ancient. Such studies provide useful proxies for use in paleoclimate reconstruction, and geochemical records of past aqueous surface environments. These studies also offer analogs to martian sedimentary deposits, and while terrestrial samples will never be the perfect analog for the surface of Mars, they certainly give us a good place to start!

VNIR Record of Lake Towuti Sediment Core
Core Spectral Parameter Plot
1900 nm absorption band shape vs. time in a sediment core from Lake Towuti, Indonesia. My past work has identified major shifts in the mineralogy of Lake Towuti sediment over the past ~40 kyr that are linked to external paleoenvironmental forcings (see also Goudge et al., GSAB, 2017).

 

Relevant Publications and Abstracts:

Goudge, T. A., J. M. Russell, J. F. Mustard, J. W. Head, and S. Bijaksana (2017), A 40,000 year record of clay mineralogy at Lake Towuti, Indonesia: Paleoclimate reconstruction from reflectance spectroscopy and perspectives on paleolakes on Mars, Geol. Soc. Amer. Bull. , in press, DOI: 10.1130/B31569.1.

Weber, A. K., J. M. Russell, T. A. Goudge, M. R. Salvatore, J. F. Mustard, and S. Bijaksana (2015), Characterizing clay mineralogy in Lake Towuti, Indonesia, with reflectance spectroscopy, J. Paleolimnol., 54, 253-261, DOI: 10.1007/s10933-015-9844-4.


Quantitative Mineralogy from Spectroscopy:

VNIR reflectance spectroscopy is a good tool for confidently identifying many different mineral phases; however, deriving quantitative mineralogy from these data is more difficult. Complications mainly arise from non-linear mixing of material spectral properties in the VNIR, where darker minerals tend to be over-represented in mixture spectra. Semi-empirical approaches have been developed to look past this non-linear mixing, and I am interested in applying such techniques to VNIR data of both terrestrial sedimentary samples and the surface of Mars, such as data from the CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) instrument.

Modeled VNIR and TIR Spectra
Kashira Mixing Plot
Measured and modeled TIR (thermal infrared; top plot) and VNIR (bottom plot) spectra of an alteration mineral-bearing deposit on Mars. My past research has involved integrating data from these two complementary wavelength regions to provide improved constraints on the abundance of aqueous alteration minerals on Mars (see also Goudge et al., Icarus, 2015).

 

Relevant Publications and Abstracts:

Goudge, T. A., J. F. Mustard, J. W. Head, M. R. Salvatore, and S. M. Wiseman (2015), Integrating CRISM and TES hyperspectral data to characterize a halloysite-bearing deposit in Kashira crater, Mars, Icarus, 250, 165-187, DOI: 10.1016/j.icarus.2014.11.034.


 

If you want more information on any of the projects that I have worked on in the past or the projects that I am currently working on, please feel free to shoot me an email!


Timothy A. Goudge | Postdoctoral Fellow | Jackson School of Geosciences
Please feel free to email me at: tgoudge <at> jsg <dot> utexas <dot> edu
Last updated: 3/6/2017