Regolith Exploration Geochemistry in Tropical and Subtropical Terrains: Handbook of Exploration Geochemistry

The use of exploration geochemistry has increased enormously in the last decade. The present volume specifically addresses those geochemical exploration practices appropriate for tropical, sub-tropical and adjacent areas – in environments ranging from rainforest to desert. Practical recommendations are made for the optimization of sampling, and analytical and interpretational procedures for exploration according to the particular nature of tropically weathered terrains. The underlying theme is the recognition that regions between 35°N and 35°S in particular have a common history of deep chemical weathering and lateritization during the late Mesozoic and early Tertiary. This has had a profound and lasting effect, so that the surface geochemical expressions of mineralization throughout these regions have many similar features, with local modification due to more recent weathering under changed climates. The volume discusses the data derived from numerous research and case studies in terms of exploration and dispersion models based on the weathering and geomorphological history. The models permit valid comparisons between equivalent terrains that may be geographically widely separated and situated in quite different climatic environments. The basis of the volume is to view geochemical dispersion within the context of a genetic understanding of the evolution of landforms and the regolith (i.e. landscape geochemistry) and to develop exploration procedures based on this understanding. This book should be of interest to exploration geochemists, economic geologists, soil scientists, geomorphologists and environmental geochemists Content: Handbook of Exploration Geochemistry Page II Front Matter Page III Copyright page Page IV Editor's Foreword Pages V-VI G.J.S. Govett Preface Page VII Charles Butt, Hubert Zeegers List of Contributors Pages IX-X Introduction Pages 1-2 Chapter I.1 - Climate, Geomorphological Environment and Geochemical Dispersion Models Pages 3-24 C.R.M. Butt, H. Zeegers Chapter I.2 - Chemical Weathering Pages 25-40 Jean-Jacques Trescases Chapter I.3 - The Ferruginous Laterites Pages 41-55 D. Nahon, Y. Tardy Chapter I.4 - Soil Formation in Tropically Weathered Terrains Pages 57-77 Y. Lucas, A. Chauvel Chapter I.5 - The Chemical Mobility and Transport of Elements in the Weathering Environment Pages 79-96 M.R. Thornber Chapter I.6 - Physical Weathering and Dispersion Pages 97-113 C.R.M. Butt Chapter II.i - Introduction Pages 115-118 G.F. Taylor, M.R. Thornber Chapter II.1 - The Mechanisms of Sulphide Oxidation and Gossan Formation Pages 119-138 M.R. Thornber, G.F. Taylor Chapter II.2 - Gossan and Ironstone Surveys Pages 139-202 G.F. Taylor, M.R. Thornber Chapter III.1 - Seasonally Humid Tropical Terrains (Savannas) Pages 203-240 H. Zeegers, P. Lecomte Chapter III.2 - Humid Tropical Terrains (Rainforests) Pages 241-294 Paul Lecomte, Hubert Zeegers Chapter III.3 - Semiarid and Arid Terrains Pages 295-391 C.R.M. Butt Chapter IV.1 - Dissected Terrains and Tropical Mountains Pages 393-418 C.R.M. Butt, H. Zeegers Chapter V.1 - Diamond Exploration in Tropical Terrains Pages 419-437 G.P. Gregory, A.J.A. Janse Chapter V.2 - Uranium Exploration in Tropical Terrains Pages 439-460 F. Bianconi, K. Kögler Chapter V.3 - The Geochemistry of Gold in Lateritic Terrains Pages 461-482 D.J. Gray, C.R.M. Butt, L.M. Lawrance Chapter V.4 - Heavy Mineral Surveys in Exploration of Lateritic Terrain Pages 483-498 G. Friedrich, A. Marker, M. Kanig Chapter VI.1 - Summary and Procedural Recommendations Pages 499-512 H. Zeegers, C.R.M. Butt Appendix 1 - — Sample Media Used in Geochemical Exploration in Tropically Weathered Environments: Definitions and use Pages 513-523 Appendix 2 - — Sample Preparation and Analysis Pages 523-531 Appendix 3 - — Profile Terminology and Glossary of Terms Pages 531-544 References Pages 545-577 Author Index Pages 579-585 Place Index Pages 586-592 Subject Index Pages 593-607 Introduction / C.r.m. Butt And H. Zeegers -- Pt. I. Characteristics Of Tropically Weathered Terrains. Ch. I.1. Climate, Geomorphological Environment And Geochemical Dispersion Models / C.r.m. Butt And H. Zeegers. Ch. I.2. Chemical Weathering / J.-j. Trescases. Ch. I.3. The Ferruginous Laterites / D. Nahon And Y. Tardy. Ch. I.4. Soil Formation In Tropically Weathered Terrains / Y. Lucas And A. Chauvel. Ch. I.5. The Chemical Mobility And Transport Of Elements In The Weathering Environment / M.r. Thornber. Ch. I.6. Physical Weathering And Dispersion / C.r.m. Butt -- Pt. Ii. Gossan Formation And Gossan Surveys. Ch. Ii.i. Introduction / G.f. Taylor And M.r. Thornber. Ch. Ii. 1. The Mechanisms Of Sulphide Oxidation And Gossan Formation / M.r. Thornber And G.f. Taylor. Ch. Ii. 2. Gossan And Ironstone Surveys / G.f. Taylor And M.r. Thornber -- Pt. Iii. Exploration In Areas Of Low To Moderate Relief. Ch. Iii. 1. Seasonally Humid Tropical Terrains (savannas) / H. Zeegers And P. Lecomte. Ch. Iii. 2. Humid Tropical Terrains (rainforests) / P. Lecomte And H. Zeegers. Ch. Iii. 3. Semiarid And Arid Terrains / C.r.m. Butt -- Pt. Iv. Exploration In Areas Of Moderate To High Relief. Ch. Iv. 1. Dissected Terrains And Tropical Mountains / C.r.m. Butt And H. Zeegers -- Pt. V. Specific Commodities And Techniques. Ch. V.1. Diamond Exploration In Tropical Terrains / G.p. Gregory And A.j.a. Janse. Ch. V.2. Uranium Exploration In Tropical Terrains / F. Bianconi And K. Kogler. Ch. V.3. The Geochemistry Of Gold In Lateritic Terrains / D.j. Gray, C.r.m. Butt And L.m. Lawrance. Ch. V.4. Heavy Mineral Surveys In Exploration Of Lateritic Terrain / G. Friedrich, A. Marker And M. Kanig -- Pt. Vi. Synthesis And Conclusions. Ch. Vi. 1. Summary And Procedural Recommendations / H. Zeegers And C.r.m. Butt -- Appendix 1. Sample Media Used In Geochemical Exploration In Tropically Weathered Environments: Definitions And Use -- Appendix 2. Sample Preparation And Analysis. Appendix 3. Profile Nomenclature And Glossary. Edited By C.r.m. Butt, H. Zeegers. Includes Bibliographical References (p. [545]-577) And Index.