Current research projects include:
How fast do minerals react with salty water? What secondary minerals form in these environments? Can we detect evidence of high-salinity alteration on Mars and other planetary bodies? We are working to answer these questions via mineral dissolution experiments in high salinity brines, supported by NASA. Recent publications include:
Steiner MH, Hausrath EM, Elwood Madden ME, Ehlmann BL, Olsen AA, Gainey SR (2016) Dissolution of Nontronite in Low Water Activity Brines and Implications for the Aqueous History of Mars, Geochimica et Cosmochimica Acta 195, 259-276.
Miller, J. L., Madden, A. E., Phillips-Lander, C. M., Pritchett, B. N., & Madden, M. E. (2016). Alunite dissolution rates: Dissolution mechanisms and implications for Mars. Geochimica et Cosmochimica Acta, 172, 93-106.
Dixon E, Elwood Madden AS, Hausrath E, Elwood Madden ME, (2015) Assessing hydrodynamic effects on jarosite dissolution rates, reaction products, and particle lifetimes, JGR-Planets DOI: 10.1002/2014JE004779
Pritchett BN, Elwood Madden ME, Madden AS (2012) Jarosite dissolution rates and maximum lifetimes in high salinity brines: Implications for Earth and Mars. Earth and Planetary Science Letters, v. 357–358, 327–336.
Effects of Climate on Chemical Weathering in Fluvial Sediments
What clues can we observe in fluvial sediments that will help us determine the climate in which these clastic sediments formed? Do glacially generated sediments weather differently than sediments produced in warmer climates? How does reactive surface area affect chemical weathering of primary minerals in different climates? Through collaborations with sedimentologist Lynn Soreghan and her students, we have conducted five field studies to compare fluvial sediment textures and chemical weathering indicators under different modern climate conditions funded by NSF. Reactive surface area experiments are underway, funded by a follow-up grant from NSF.
McMurdo Dry Valleys, Antarctica (Cold + Arid)
Marra, KR, Elwood Madden, ME, Soreghan, GS, Hall, BL (2015) BET surface area distributions in polar stream sediments: implications for silicate weathering in a cold-arid environment, Applied Geochemistry 52, 31-42.
Stumpf AR, Elwood Madden ME, Soreghan GS, Hall BL, Keiser LJ, Marra KR (2012) Glacier meltwater stream chemistry in Wright and Taylor Valley, Antarctica: Significant roles of drift, dust, and biological processes in chemical weathering in a polar climate. Chemical Geology, 322-323, 79-90.
Josteldalsbreen, Norway (Cold + Wet)
Anza Borrego, Southern California (Hot + Arid)
Rio Guyana, Peurto Rico (Hot + Wet)
Wichita Mountains, Oklahoma (Warm, Semi-Arid)
Gas Hydrate (Clathrates) in Planetary Systems
How fast does gas react with ice to form clathrates at low temperatures? How quickly do these clathrate compounds dissociate to form ice and gas under low temperature and pressure conditions? How do gases diffuse through ice and clathrate at low temperatures? We recently acquired a High Resolution Mapping Raman Microscope/Spectrometer to observe volatile behavior in ice and clathrates under planetary analog conditions. Recent publications include:
Mousis O, Chassefiere E, Chevrier V, Elwood Madden ME, Lakhlifi A, Lunine JI, Montmessin F, Picaud S, Schmidt F, and Swindle TD (2013) Volatile trapping in Martian clathrates. Space Science Reviews v. 173, 213–250.
Raman Analysis of High Salinity Brines
Can we use Raman spectroscopy to measure aqueous solutes in high salinity brines? How can we apply these techniques to measure aqueous solutes remotely on other planetary bodies? The Fall 2015 GeoWriting class developed initial calibration curves for solutes in high salinity brines. Research is ongoing to continue this investigation.
McGraw, LE, Elwood Madden ME, Phillips- Lander CM, Parnell S, 2016 Development of a Rapid, Nondestructive Method to Measure Aqueous Carbonate and Perchlorate in High Salinity Brines using Raman Spectroscopy. LPSC, The Woodlands, TX, Abstract # 2728.
M.E. Elwood Madden, C. M. Phillips-Lander, J. W. Burkhart, J. R. Johnson, C. R. Kosemund, A. L. Lewis, B. S. Turner, S. D. Williams, J. M. Shaiman, 2016 Raman Measurement of Solute Chemistry in Brines for Remote Analysis of Planetary Fluids. LPSC, The Woodlands, TX, Abstract # 1131.