The Geochemistry of the Paranamp;#x00E1; River: An Overview.

River basins are not inert continental features. Moreover, it can be said that rivers have a life, and their evolution is usually predictable. In biological terms, for example, rivers are processors of materials as the biota they contain take up, convert, use, and release resources that come to them. In other words, rivers are active biological systems that metabolize the organic matter they transport. From a geological point of view, rivers transport sediments and solutes whose dynamics is also determined by a set of complex interacting variables, such as lithology, climate, and relief. Consequently, the water that reaches a river's mouth is far different, both qualitatively and quantitatively, from the water that entered the system as rain or snowfall. Summarizing, the chemical signatures of rivers are reflections of complex natural and interdependent relationships involving the chemistry of precipitation, the weathering of minerals, the cycling of vegetation, and the evolution or history of its water. The recently published geochemical treatise (Drever 2005) is a major step towards the elucidation of such complexities. [ABSTRACT FROM AUTHOR]