The Analysis of Picogram Quantities of Rare Earth Elements in Naturual Waters -- Determination of 56 Trace Elements in Three Aquifer- Type Rocks by ICP-MS and Approximation of the Relative Solubilities for These Elements in a Carbonate System by Water-Rock Concentration Ratios -- Rare Earth, Major, and Trace Element Geochemistry of Surface and Geothermal Waters from the Taupo Volcanic Zone, North Island New Zealand -- The Aqueous Geochemistry of the Rare Earth Elements and Yttrium. Part 13: REE Geochemistry of Mine Drainage from the Pine Creek Area, Coeur d'Alene River Valley, Idaho, USA -- Lanthanide Elements in Alteration Minerals as a Guide to Transport Phenomena in the Vadose Zones of Continental Tuffs -- Origin of Rare Earth Element Signatures in Groundwaters of South Nevada, USA: Implications from Preliminary Batch Leach Tests Using Aquifer Rocks -- Rare Earth Element Contents of High pCO2 Groundwaters of Primorye, Russia: Mineral Stability and Complexation Controls -- Geochemistry of Rare Earth Elements in Groundwaters from a Rhyolite Aquifer, Central México -- Rare Earth Element Concentrations, Speciation, and Fractionation along Groundwater Flow Paths: The Carrizo Sand (Texas) and Upper Floridan Aquifers -- Rare Earth Elements (REE) and Nd and Sr Isotopes in Groundwater and Suspended Sediments from the Bathurst Mining Camp, New Brunswick: Water-Rock Reactions and Elemental Fractionation.Rare Earth Elements in Groundwater Flow Systems is the first volume of its kind entirely focused on the geochemistry of the lanthanide series elements in groundwater/aquifer environments. Consisting of ten chapters, each of which is an original, peer-reviewed contribution by some of the leading researchers in the study of the low-temperature geochemistry of rare earth elements, the volume addresses analytical techniques, water-rock interactions, aqueous complexation, and the reactions/processes that influence these heavy metals along groundwater flow paths.