A chief goal of this book is to help the reader understand controls on the chemical quality of surfaceand subsurface-waters, both pristine and polluted. The focus is on inorganic processes and on the chemistry of soil and ground waters, with less said about the chemistry of precipitation, surfacewaters, or the ocean. The book leans heavily on the principles of chemical thermodynamics and the concept of chemical equilibrium. Chemical equilibrium, whether attainable or not, represents the reference state for purposes of explaining the concentrations of aqueous species in the hydrosphere. Concepts of chemical kinetics are introduced when they are known and seem applicable.  <...>

The Argentine Precordillera (“Precordillera”) is part of a larger terrane which is exotic to the western margin of Gondwana. This larger terrane is characterized by a Grenvillian-type basement and the presence of Laurentian carbonate-platform rocks of Cambrian–Ordovician age. The original position of the terrane is interpreted to be the Ouachita embayment of southeastern Laurentia.

Arid environments cover more than one-third of the world’s land area and represent the most common habitat on Earth after the oceans. Aridity poses a threat to the environment, as well as the economy, security, development, food security, and social life around the world. The causes of increased aridity are complex and are thought to be both natural and man-made. Factors such as climate change, population growth, soil erosion, inappropriate irrigation, wrong farming, soil, water, and groundwater contamination, urbanization, deforestation, improper water management, desertification of arid and semiarid zones appear as causes of drought.

This book covers a wide range of scientific research studies, from water management to groundwater management, from land rehabilitation to soil reclamation, which will help prevent and minimize man-made aridity. In addition, many studies related to aridities such as environmental education, environmental awareness, sustainable development, and management policies and plans are also welcome. <...>

Multivariate statistical methods have become commonplace in the Earth Sciences. What was once an exclusive area of activity is now within the reach of Everyman, owing to the ubiquitousness of mini-computers and the ready availability of software for doing the computing. In the days when one was required to do one's own programming, it was necessary to acquire considerable proficiency in linear algebra and one or more programming languages. Today, the vast majority of the people who use multivariate methods to analyse geological data have little or no idea of the matrix operations underlying a particular method, nor, for that matter, what the program is actually supposed to be doing. This situation can be both good and bad. It can do no harm if everything goes according to schedule, the program being used is competently constructed, which, alas, is far from being the general case, and there are no strong deviations from standard statistical theory in the data under examination. It is bad if the data do not fit the theoretical requirements of a particular method and even worse if the method of computation used is inappropriate. It is an inescapable and sad fact of life that much geological and biological material deviates in some manner or other from the theoretical requirements of a multivariate statistical procedure. The immediate relevance of this observation is that there are many sources of error in doing an analysis of geological data by means of standard statistical software.