URANIUM CONTENT OF SURFACE WATER IN SAN MARCOS RIVER

On the surface of the earth, the presence of naturally occurring uranium and its concentration varies according to the type of rock. The cycle begins with uranium geological weathering process in the crust and continues its movement through surface and ground water. The objective of this study was to evaluate the transport of uranium through the levels of natural radioactivity in water from the San Marcos River which is located in the central part of the State of Chihuahua. The concentrations of 238U and 234U environmental level were obtained by liquid scintillation analysis (LSA), using a spectrometer PERALS (photon/electronrejecting alpha scintillation liquid). In water samples were observed dissolved uranium values 6-239 mBq L^-1. For major ion content of the river water is classified as Calciobiocarbonatada. We observed an increase in the concentrations of uranium in the points that are after uranium ore outcrop. Taking into account the conditions of the river type, mostly intermittent, where water flows in a subsurface well as the correlation of total uranium dissolved in potassium and calcium, one can conclude that the uranium content in different types of rocks that form the basin and groundwater supply high uranium content may explain the presence of uranium isotopes (234U mostly) in the surface waters.