Research

My research goals are diversified and relate directly to a wide range of issues within hydrogeology, paleoclimatology, and mantle geochemistry. My current research addresses problems in distinct geological environments, in particular, sedimentary (e.g., Gulf Coast Basin, Michigan Basin), volcanic (e.g., Galapagos Islands), and glacial (Antarctica) at the aide of complementary tools (e.g., noble gas geochemistry, numerical modeling, geostatistical methods). The common link to all my research projects is the analysis of the whole set of stable noble gases (He, Ne, Ar, Kr, Xe) in a diversity of fluids both at depth (e.g., groundwater, brine, gas) and at the surface (e.g., ice, snow, rain water).

Some examples of new and on-going research projects:

1. Investigating the nature of a noble gas mantle component in the deep brines of the Michigan Basin and its implications for mantle convection models.
2. Investigating the behavior of noble gases at the interface unsaturated zone/water table and developing new noble gas temperature models to improve noble gas paleoclimatic reconstructions.
3. Investigating the behavior of all noble gases in ice and sealed lakes in Antarctica through a combined analysis of concentrations and isotopic ratios to reconstruct both the sealing history of these lakes as well a to clarify some aspects of the tectonic history of this region.
4. To obtain an in-depth and overall understanding of the hydrogeological functioning of the Galapagos Islands through noble gases in order to evaluate their aquifers’ potential as long term water suppliers and to prevent future groundwater contamination.
   

Selected Publications                                        *Student Advisee

Castro M.C., *Ma L., Hall, C.M. (2009), A Primordial, Solar He-Ne Signature in Crustal Fluids of a Stable Continental Region, Earth Planetary Science Letters, 279, 174-184.

*Ma, L., Castro, M.C., and Hall, C.M. (2009), Crustal noble gases in deep brines as natural tracers of vertical transport processes in the Michigan Basin, Geochemistry Geophysics Geosystems, 10, 6, Q06001, doi:10.1029/2009GC002475.

*Ma L., Castro M.C., Hall C.M. (2009), Atmospheric noble gas signatures in deep Michigan Basin brines as indicators of a past thermal event, Earth Planetary Science Letters, 277 (137-147).

*Sun T., Hall, C. M., Castro, M.C., K. C. Lohmann, Goblet P. (2008), Excess Air in the Noble Gas Groundwater Paleothermometer: A New Model Based on Diffusion in the Gas Phase, Geophys. Res. Lett., 35, L19401, doi:10.1029/2008GL035018.

Castro M.C., Hall, C.M., Patriarche D., Goblet P., and *Ellis, B.R. (2007), A New Noble Gas Paleoclimate Record in Texas - Basic Assumptions Revisited, Earth Planetary Science Letters, 157 (1-2), 170-187, :10.1016/j.epsl.2007.02.030.

Castro M.C., Patriarche D., and Goblet P. (2005), 2-D Numerical Simulations of Groundwater Flow, Heat Transfer and 4He transport - Implications for the He Terrestrial Budget and the Mantle Helium-Heat Imbalance, Earth Planetary Science Letters, 237, 893-910.
 
Patriarche D., Castro M.C., and Goovaerts P. (2005), Estimating Regional Hydraulic Conductivity Fields – a Comparative Study of Geostatistical Methods, Mathematical Geology, 37, 6, 587-611.
 
Castro M.C., and Goblet P. (2005), Calculation of Groundwater ages - a Comparative Analysis, Ground Water, 43, 3, 368-380.
 
Saar M.O., Castro M.C., Hall, C.M., Manga M., and Rose, T.P. (2005) Quantifying magmatic, crustal, and atmospheric helium contributions to volcanic aquifers using all stable noble gases: Implications for magmatism and groundwater flow, Geochemistry, Geophysics, Geosystems, 6, 3, Q03008, doi:10.1029/2004GC000828.
 
*Ma L., Castro M.C., and Hall C.M. (2004), A late Pleistocene–Holocene noble gas paleotemperature record in southern Michigan, Geophys. Res. Lett., 31, L23204, doi:10.1029/2004GL021766.
 
Patriarche, D., Castro M.C., and Goblet P. (2004), Large-scale hydraulic conductivities inferred from three-dimensional groundwater flow and 4He transport modeling in the Carrizo aquifer, Texas, J. Geophys. Res., 109, B11202, doi:10.1029/2004JB003173.
 
Castro M.C. (2004), Helium sources in passive margin aquifers - new evidence for a significant mantle 3He source in aquifers with unexpectedly low in-situ 3He/4He production, Earth Planetary Science Letters, 222, 897-913 .
 
Castro, M. C., and P. Goblet, (2003) Calibration of regional groundwater flow models: Working toward a better understanding of site-specific systems, Water Resour. Res., 39(6), 1172, doi:10.1029/2002WR001653.

Castro M. C., Stute M., and Schlosser P. (2000) Comparison of 4He and 14C ages in simple aquifer systems: implications for groundwater flow and chronologies, Appl. Geochemistry, 15, 1137-1167.

Castro M. C., Goblet P., Ledoux E., Violette S, and Marsily. G. de. (1998) Noble gases as natural tracers of water circulation in the Paris Basin. 2. Calibration of a groundwater flow model using noble gas isotope data, Water Resources Research, vol. 34, 10, 2467-2483.