My research interests focus on fundamental igneous and tectonic processes that lead to the formation of oceanic and continental crust. Recent projects have centered on magmatism and faulting along the Mid-Atlantic Ridge (MAR), and the petrogenesis of silicic rocks recovered from modern ocean crust and ophiolites. Rock samples recovered by deep sea drilling and dredge along the MAR reveal a high degree of heterogeneity in both structure and composition, and offer an unprecedented view of how magmatism, faulting, and water-rich fluids interact to produce and modify new igneous crust. These rocks also offer a direct link to the underlying MORB mantle, enabling characterization of the chemical heterogeneity within the mantle and furthering our understanding of crust-mantle evolution.
On the continents, my collaborators and I are engaged in an NSF-supported project designed to characterize the initiation of a low-angle normal fault system in the Mojave Desert, CA. These theoretically-problematic faults have also been recognized along rifted continental margins and mid-ocean ridge plate boundaries, where they expose mid-lower crustal and mantle rocks directly onto the Earth surface. Our goals include establishing the mechanism by which these faults initiate and subsequently slip, and assessing their seismic potential. Mineral-fluid interactions are likely critical for localizing strain and allowing slip to occur, yet the role of these processes in the natural environment has not been fully constrained.
Additional research interests involve the application of accessory mineral geochemistry to studying petrologic processes, provenance in orogenic belts and detrital settings, and crustal evolution with time. I am always looking for students interested in participating in, and expanding upon, these projects. My research group engages in both field and lab studies, and uses a diverse set of tools that includes a simple hand lens and petrographic microscope, along with more advanced instrumentation including Scanning Electron Microscopy (SEM), X-ray Fluorescence (XRF), and Secondary Ion Mass Spectrometry (SIMS).
- Schoolmeesters, N., Cheadle, M.J., John, B.E., Reiners, P.W., Gee, J., Grimes, C.B., 2012, The cooling history and the depth of detachment faulting at the Atlantis Massif oceanic core complex. Geochemistry, Geophysics, Geosystems doi:10.1029/2012GC004314.
- Grimes, C.B., Cheadle, M.J., John, B.E., Reiners, P.W., and Wooden, J.L., 2011, Cooling rates and the depth of detachment faulting at oceanic core complexes: Evidence from zircon Pb/U and (U-Th)/He ages, Geochem. Geophys. Geosyst., 12, Q0AG01, doi:10.1029/2010GC003391. [Abstract]
- Grimes, C.B., Ushikubo, T., John, B.E., Valley, J.W., 2011, Uniformly mantle-like δ18O in zircons from oceanic plagiogranites and gabbros. Contributions to Mineralogy and Petrology. doi:10.1007/s00410-010-0519-x. [Abstract]
- Blackman D.K., Ildefonse B., John B.E., Ohara Y., Miller D.J. and IODP 304-305 Science Party [C.B. Grimes as part of scientific party], 2011, Drilling constraints on lithospheric accretion and evolution at Atlantis Massif, Mid-Atlantic Ridge 30°N. J. Geophys. Res., doi:10.1029/2010JB007931. [Abstract]
- Wanless, V.D., Perfit, M.R., Ridley, W.I., Wallace, P., Grimes, C.B., and Klein, E.M., 2011, Volatile abundances and oxygen isotopes in basaltic to dacitic lavas on mid-ocean ridges: The role of assimilation at spreading centers. Chemical Geology, doi:10.1016/j.chemgeo.2011.05.017. [Abstract]
- Elliot, D.H., Grimes, C.B., 2011, Triassic and Jurassic strata at Coombs Hills, south Victoria Land: stratigraphy, petrology and cross-cutting breccia pipes. Antarctic Science, doi: 10.1017/S0954102010000994.
- Cheadle, M., Grimes, C.B., 2010, Structural geology: To fault or not to fault, Nature Geoscience, 3, News and Views. doi:10.1038/ngeo910. [Abstract]
- Schwartz, J.J., John, B.E., Cheadle, M.J., Wooden, J.L., Mazdab, F., Swapp, S., Grimes, C.B., 2010, Dissolution-Reprecipitation of Igneous Zircon in Mid-Ocean Ridge Gabbro, Atlantis Bank, Southwest Indian Ridge. Chemical Geology. doi:10.1016/j.chemgeo.2010.03.017.
- Grimes, C.B., John, B.E., Cheadle, M.J., Schwartz, J., Mazdab, F.K., Swapp, S., Wooden, J., 2009, On the occurrence, trace element geochemistry, and crystallization history of zircon from in situ ocean lithosphere. Contributions to Mineralogy and Petrology. doi:10.1007/s00410-009-0409-2. [Abstract]
- Baines, A.G., Cheadle, M.J., John, B.E., Grimes, C.B., Schwartz, J.J., and Wooden, J., 2009, Rapid accretion of gabbroic crust at the ultra-slow-spreading SW Indian Ridge. Earth and Planetary Science Letters. doi:10.1016/j.epsl.2009.09.002.
- John B.E., Cheadle M.J., Gee J.S., Grimes C.B., Morris A., Pressling N., 2009, Data report: spatial and temporal evolution of slow spread oceanic crust—graphic sections of core recovered from IODP Hole U1309D, Atlantis Massif, 30°N, MAR (including Pb/U zircon geochronology and magnetic remanence data). Proc. IODP, v. 304/305. doi:10.2204/iodp.proc.304305.205.2009
- Morris, A., Gee, J.S., Pressling, N., John, B.E., MacLeod, C.J., Grimes, C.B., Searle, R.C., 2009, Footwall rotation in an oceanic core complex quantified using reoriented Integrated Ocean Drilling Program core samples. Earth and Planetary Science Letters. doi:10.1016/j.epsl.2009.08.007.
- Grimes, C.B., John, B.E., Cheadle, M.J., and Wooden, J.L., 2008, Protracted construction of gabbroic crust at a slow-spreading ridge: Constraints from 206Pb/238U zircon ages from Atlantis Massif and IODP Hole U1309D (30°N, MAR). Geochemistry, Geophysics, Geosystems (G3), 9. doi: 10.1029/2008GC002063. [Abstract]
- Grimes, C.B., John, B.E., Kelemen, P.B., Mazdab, F., Wooden J.L., Cheadle, M.J., Hanghoj, K., and Schwartz, J.J., 2007, The trace element chemistry of zircons from oceanic crust: A method for distinguishing detrital zircon provenance. Geology, 35, 643-646. [Abstract]
- Elliot, D.H., Fortner, E.H., and Grimes, C.B., 2006, Mawson breccias intrude Beacon strata at Allan and Coombs Hills, south Victoria Land: regional implications. In Futterer, D.K., Damaske, D., Kleinschmidt, G., Miller, H., and F. Tessensohn, (editors), Antarctica: Contributions to global earth sciences: Proceedings of the 9th International Symposium on Antarctic Earth Sciences. Springer-Verlag, Berlin, p. 291-298.
- Blackman D.K., Ildefonse B., John B.E., Ohara Y., Miller D.J., MacLoed C.J. and the Expedition 304/305 Scientists, 2006, Proc. IODP, 304/305: College Station, TX (Integrated Ocean Drilling Program Management International, Inc.). doi:10.2204/iodp.proc.304305.2006
- Schwartz J., John B.E., Cheadle M.J., Miranda E., Grimes C.B., Wooden J., and Dick H.J.B., 2005, Inherited zircon and the magmatic construction of oceanic crust. Science, 310, 654-657.
Current M.S. Advisees
- Christine Thomas, thesis entitled, "Hafnium isotope geochemistry of gabbroic crust sampled along the Mid-Atlantic Ridge: Constraints on the mantle source for crust forming magmas".
- Cody MacDonald, thesis entitled, "The role of fluids in the early slip history of a detachment normal fault, Chemehuevi Mountains, CA".
- GEOL 3120/5120: Earth Materials
- GEOL 3200: Petrology
- GEOL 4910/6910: Economic Geology