Research Interests
I) Deep-Seated Fluids
Aqueous and CO2-rich fluids play a very important - yet poorly understood - role in the chemical evolution of our planet. As geochemical transport agents, the important role of fluids stems from their extreme mobility (compared to melts or rocks), the high diffusivities of their solutes (deep-seated fluids are excellent solvents for certain chemical components), and even from their strong effect on the melting relations of rocks.
I've been working with Bruce Watson, Jonathan Price, and Jay Thomas to characterize the transport properties of fluids in the deep earth. This work, sponsored by the Department of Energy's office of Basic Energy Sciences, is taking place in Watson's Experimental Geochemistry Laboratory.
II) Ti-in-Quartz (TitaniQ), Ti-in-Zircon, and Zr-in-Rutile Thermometry
We have recently established three new trace-element geothermometers. These include:
- TitaniQ (Ti in Quartz). Link
- Zr in Rutile Link
- Ti in Zircon Link
III) Volcanic Systems
My field-based research has been directed toward study of large-volume, silicic magma systems (supervolcanoes!). Past work focused on the enormous volumes of silicic ash-flow tuff and lavas extruded from large caldera complexes during the mid-Tertiary "ignimbrite flareup" in western Mexico. I'm now revisiting the Bishop Tuff (Long Valley caldera, California), by applying the TitaniQ thermometer to better constrain the thermal history of the magma system that fed the huge 0.76 Ma eruption.
Selected Publications
Trace-element thermometry
- Cherniak, DJ, Watson, EB, and Wark, DA, 2007, Ti diffusion in quartz, Chemical Geology, 236:65-74, doi: doi:10.1016/j.chemgeo.2006.09.001 Link
- Spear, FS, Wark, DA, Cheney, JT, Schumacher, JC, and Watson, EB, 2006, Zr-in-rutile thermometry in blueschists from Sifnos, Greece: Contriibutions to Mineralogy and Petrology, 152: 375-385, doi: 10.1007/s00410-006-0113-4. Link
- Wark, DA, Hildreth, W, Spear, FS, Cherniak, DJ, and Watson, EB, 2007, Pre-eruption recharge of the Bishop magma system: Geology. Link
- Wark, DA, and Watson, EB, 2006, TitaniQ: A Titanium-in-Quartz geothermometer: Contributions to Mineralogy and Petrology, 152:743-754, doi: 10.1007/s00410–006–0132–308 Link
- Watson, EB, Wark, DA, and Thomas, JB, 2006, Crystallization thermometers for zircon and rutile: Contributions to Mineralogy and Petrology, 151: 413-433, doi: 10.1007/s00410-006-0068-5. Link
Deep-seated fluids and melts
- Wark, DA, and Watson, EB, 2004, Interdiffusion of H2O and CO2 in metamorphic fluids at 490-690°C and 1 GPa, Geochimica et Cosmochimica Acta, 68, 2693-2698, doi:10.1016/j.gca.2003.12.006
- Wark, DA, Williams, CA, Watson, EB, and Price, JD, (2003) Reassessment of Pore Shapes in Microstructurally Equilibrated Rocks, with Implications for Permeability of the Upper Mantle, Journal of Geophysical Research, 108, 2050, doi:10.1029/2001JB001575.
- Wark, DA, and Watson, EB, 2002, Grain-scale channelization of pores due to gradients in temperature or composition of intergranular fluid or melt: Journal of Geophysical Research, 107(B2), 10.1029/2001JB000365, 2002.
- Liang, Y, Price, JD, Wark, DA, and Watson, EB, 2001, Nonlinear pressure diffusion in a porous medium: Approximate solutions with applications to permeability measurements using transient pulse-decay method: Journal of Geophysical Research, 106, 529-536.
- Wark, DA, and Watson, EB, 2000, Effect of grain size on fluid and melt distribution in the mantle and deep crust: Geophysical Research Letters, 27, 2029-2032.
- Wark, DA, and Watson, EB, 1998, Grain-scale permeabilities of texturally equilibrated, monomineralic rocks: Earth & Planetary Science Letters, 164, 591-605.
- Watson, EB, and Wark, DA, 1997, Diffusion of dissolved silica in H2O at 10 GPa, with implications for mass transport in the crust and upper mantle,Contributions to Mineralogy and Petrology, 130, 66-80.
Large-volume volcanic systems
- Wark, DA, Hildreth, W, Spear, FS, Cherniak, DJ, and Watson, EB, in press, Pre-eruption Recharge of the Bishop magma system: Geology. Link
- Masturyono, McCaffrey, R, Wark, DA Roecker, SW, Fauzi, Ibrahim, G, and Sukhyar, 2001, Distribution of Magma Beneath Toba Caldera, North Sumatra, Indonesia, Constrained by 3-Dimensional P-wave Velocities, Seismicity, and Gravity Data:, Geochemistry, Geophysics, and Geosystems, Paper number 2000GC000096
- McDowell, FW, Housh, TB, and Wark, DA, 1999, Nature of the crust beneath west-central Chihuahua, Mexico, based upon Sr, Nd, and Pb isotopic compositions at the Tomochic volcanic center: Geological Society of America Bulletin, 111, 823-830.
- Fauzi, McCaffrey, R, Wark, DA, Sunaryo, Haryadi, PP, 1996, Lateral Variation In Slab Orientation Beneath Toba Caldera, Northern Sumatra: Geophysical Research Letters, 23, 443 – 446.
- Wark, DA, 1991, Role of mafic and intermediate-composition magmas in rhyolite genesis, northern Sierra Madre Occidental, Mexico: Journal of Geophysical Research, 96, 13,389-13,412
- Wark, DA, Kempter, K, and McDowell, F, 1990, Evolution of waning, subduction-related magmatism, northern Sierra Madre Occidental, Mexico: Geological Society of America Bulletin, 102, 1555-1564
Rapakivi texture and accessory phases
- Wark, DA, and Miller, CF, 1993, Accessory mineral behavior during evolution of a peraluminous granite suite, Sweetwater Wash Pluton, California: Chemical Geology, 110, 49-67.
- Wark, DA, and Stimac, JA, 1992, Origin of mantled (rapakivi) feldspars: Experimental evidence of a dissolution- and diffusion-controlled mechanism: Contributions to Mineralogy and Petrology, 111, 345-361.
- Stimac, JA, and Wark, DA, 1992, Mantled-feldspar textures in Clear Lake (CA) volcanic rocks and implications for the origin of rapakivi granites: Geological Society of America Bulletin, 104, 728-744
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