This volume contains a selection of papers presented to the Fourth Internation~l Symposium on Environmental Biogeochemistry (ISEB), and a conference on Biogeochemistry in Relation to Mining Industry and Environmental Pollution (Leaching Conference), held in Canberra, Aust ralia on August 26-31 and September 3-4, 1979, respectively. The ISEB were established to provide "a forum for uninhibited exchange of information and ideas among the biological, chemical, atmospheric and geolorical scientists working in the common area of biogeochemistry, encompassing soil and other earth sciences as well as the hydrosphere and atmosphere", By linking the fourth ISEB with the Leachin~ Conference the scope of discussions was extended to encompass the application of biogeochemical processes to the mining industry. This wide-ranging philosophy is reflected in the breadth and diversity of the subjects covered in this book. The published papers are expanded versions of those presented at the meetings. They have all been scrutinized by at least one referee in addition to the editors. About 20% of the contributions to the meetings are not included, either because authors did not wish to publish or because the papers were not accepted by the editors.

The most definitive manual of microbes in air, water, and soil and their impact on human health and welfare. • Incorporates a summary of the latest methodology used to study the activity and fate of microorganisms in various environments. • Synthesizes the latest information on the assessment of microbial presence and microbial activity in natural and artificial environments. • Features a section on biotransformation and biodegradation. • Serves as an indispensable reference for environmental microbiologists, microbial ecologists, and environmental engineers, as well as those interested in human diseases, water and wastewater treatment, and biotechnology.

Calcretes are an important component of many ancient fluvial, lacustrine and shallow-marine carbonate sequences, and they are widely developed in many parts of the world at the present time. Calcretes are useful to the earth scientist involved in reconstructing ancient environments, palaeoclimates and palaeographics, and they may also reveal details of soil biota and chemistry. Over the last two decades the journal Sedimentology has published a number of articles on this subject and a compilation of them is presented here. In addition to the five main sections, this volume also includes an introduction to the subject that offers a review of recent work on calcretes. The collection of papers illustrates the range of calcrete occurrences and the great variety of textures and fabrics. This volume is authored and edited by experts and will serve as more than an introduction to the subject for geologists, soil scientists and geographers. If you are a member of the International Association of Sedimentologists, for purchasing details, please see: http://www.iasnet.org/publications/details.asp?code=RP2

Collection of papers presented at three workshops, hosted by the Centre for Clean Environment Technology, Bangalore University during 1998-2001 and some contributed atricles.

Hypersaline Brines and Evaporitic Environments