Twenty contributions on diverse aspects of the environmental geochemistry in tropical and sub-tropical environments make up this monograph. They summarize original research not readily available elsewhere in the literature. Most of the chapters include extensive original data that will be very useful to researchers interested in the tropics and sub-tropics. A group of papers on methods and their applications is aimed directly at scientists involved in environmental research in the tropics. There are also some interesting intercontinental comparisons drawn on paleoclimatology, environmental impacts of mining and geochemistry of continetal shelf sediments.