By measuring the direction and intensity of magnetism in rocks of different ages, a record of the Earth's magnetic field in the past can be obtained. This 1994 book deals with the particular case of reversals of the Earth's magnetic field. These have played a major role in the development of plate tectonics and in establishing a geological time scale. The magnetism of rocks is discussed in some detail with a warning of possible misinterpretations of the record. Observational results and theories are reviewed with special attention to the structure and geometry of the transition field. Changing conditions at the core-mantle boundary, their effect on reversals, the generation of plumes and the possible correlation of reversals with tectonic changes, ice ages or mass extinctions are thoroughly discussed, including suggested periodicities in the reversal record and in other geophysical data.

Die reeks is volgens die Nasionale Kurrikulum- en Assesserings beleidsverklaring (“CAPS”) geskryf. ’n Moontlike werkskedule is ingesluit. Elke hoofstuk begin met ’n oorsig van wat onderrig word en die hulpbronne wat jy benodig. Daar is advies oor die voorgestelde pas wat jou sal help om die hele jaar se werk betyds af te handel. Ons gee by elke onderwerp raad oor hoe om konsepte bekend te stel en hoe om leerders met steierwerk voor te berei en te ondersteun. Al die antwoorde word gegee; jy bespaar dus tyd omdat jy nie die oefeninge self hoef uit te werk nie. ’n Volkleurplakkaat en ’n CD propvol hulpbronne is ook ingesluit om jou met onderrig en assessering te help. Addisionele voorbeeldvrae, toetse of assesserings take, wat jy kan kopieer, sal jou help om jou leerders effektief te assesseer.

The series was written to be aligned with CAPS. A possible work schedule has been included. Each topic start with an overview of what is taught, and the resources you need. There is advice on pave-setting to assist you in completing the work for the year on time. Advice on how to introduce concepts and scaffold learning is given for every topic. All the answers have been given to save you time doing the exercises yourself. Also included are a full-colour poster and CD filled with resources to assist you in your teaching and assessment.

Spesifiek geskryf om aan al die vereistes van die nasionale Kurrikulum- en Assessering beleidsverklaring (KABV) te voldoen. Sleutelterme word in rooi gedruk as dit vir die eerste keer verskyn. ’n Lys van hierdie terme word ook in rooi aan die begin van elke eenheid of hoofstuk gelys. Nuwe woorde is in blou en word in die kantlyn verduidelik. Aktiwiteite help leerders om te verstaan wat hulle geleer het. 'n Opsomming aan die einde van elke onderwerp help leerders studeer. Die Formele Assesserings taak (FAT) blokkie bevat take wat leerders voorberei vir die wat in die klas voltooi moet word. Vrae aan die einde van elke onderwerp help leerders met hersiening. ‘n Voorbeeld van ‘n eksamenvraestel aan die einde van die boek sal leerders ook help oefen en leer oor alles wat hulle nodig het om te weet. Gratis studiegids.

The subject of geomagnetic micropulsations has developed extremely rapidly and it is difficult to know when is an appropriate time to pause and assess the sum total of our knowledge-both observational and theoretical. There has in recent years been a tremendous increase in both the quantity and quality of data and also many theoretical ad vances in our understanding of the phenomenon. Undoubtedly there will be further progress in both areas but it seems worthwhile now to review both our knowledge and our ignorance. This book was essen tially completed by the end of April 1969 and tries to give a summary of the subject up to that time. The Earth is enclosed in the magnetosphere, a hollow carved out of the solar wind by the Earth's magnetic field. Above the ionosphere there is a very tenuous thermal plasma of partially ionized hydrogen in diffusive equilibrium with magnetic and gravitational forces, and ener getic protons and electrons that constitute the trapped Van Allen ra diation belts. Throughout this anisotropic and inhomogeneous plasma, natural and man-made electromagnetic energy propagates in a wide variety of modes and frequency bands. This book is concerned with that class of natural signals called geomagnetic micropulsations-short period (usually of the order of seconds or minutes) fluctuations of the Earth's magnetic field.

Plate tectonic theory has revolutionized the study of the history of our planet. It is now becoming increasingly apparent that processes deep within the Earth's mantle and core strongly influence plate movements, and it is to these processes that the author addresses himself. Having discussed the origin, composition, structure and physical properties of the Earth, the book turns to discuss the key role that interactions between the mantle and core play in magmatic and tectonic processes. Other important issues discussed are the nature and existence of mantle plumes and convection cells, and the similarities and differences of tectonic processes on other planets in the solar system. These and other questions are discussed in the context of the Earth's origins, its chemistry and its physics. All geophysicists and geologists concerned with earth evolution and plate tectonics should find much of interest in this book.

Provides the tools needed to analyze and solve acid drainage problems

Featuring contributions from leading experts in science and engineering, this book explores the complex biogeochemistry of acid mine drainage, rock drainage, and acid sulfate soils. It describes how to predict, prevent, and remediate the environmental impact of acid drainage and the oxidation of sulfides, offering the latest sampling and analytical methods. Moreover, readers will discover new approaches for recovering valuable resources from acid mine drainage, including bioleaching.

"Acid Mine Drainage, Rock Drainage, and Acid Sulfate Soils" reviews the most current findings in the field, offering new insights into the underlying causes as well as new tools to minimize the harm of acid drainage: Part I: "Causes of Acid Mine Drainage, Rock Drainage and Sulfate Soils" focuses on the biogeochemistry of acid drainage in different environments.Part II: "Assessment of Acid Mine Drainage, Rock Drainage and Sulfate Soils" covers stream characterization, aquatic and biological sampling, evaluation of aquatic resources, and some unusual aspects of sulfide oxidation.Part III: "Prediction and Prevention of Acid Drainage" discusses acid-base accounting, kinetic testing, block modeling, petrology, and mineralogy studies. It also explains relevant policy and regulations.Part IV: "Remediation of Acid Drainage, Rock Drainage and Sulfate Soils" examines both passive and active cleanup methods to remediate acid drainage.

Case studies from a variety of geologic settings highlight various approaches to analyzing and solving acid drainage problems. Replete with helpful appendices and an extensive list of web resources, "Acid Mine Drainage, Rock Drainage, and Acid Sulfate Soils" is recommended for mining engineers and scientists, regulatory officials, environmental scientists, land developers, and students.

A guide to environmental and communication issues related to fracking and the best approach to protect communities Environmental Considerations Associated with Hydraulic Fracturing Operations offers a much-needed resource that explores the complex challenges of fracking by providing an understanding of the environmental and communication issues that are inherent with hydraulic fracturing. The book balances the current scientific knowledge with the uncertainty and risks associated with hydraulic fracking. In addition, the authors offer targeted approaches for helping to keep communities safe. The authors include an overview of the historical development of hydraulic fracturing and the technology currently employed. The book also explores the risk, prevention, and mitigation factors that are associated with fracturing. The authors also include legal cases, regulatory issues, and data on the cost of recovery. The volume presents audit checklists for gathering critical information and documentation to support the reliability of the current environmental conditions related to fracking operations and the impact fracking can have on a community. This vital resource: Contains the technical information and mitigation recommendations for safety and environmental issues related to hydraulic fracturing Offers an historical overview of conventional and unconventional oil and gas drilling Explains the geologic and technical issues associated with fracking of tight sand and shale formulations Presents numerous case studies from the United States EPA and other agencies Discusses issues of co-produced waste water and induced seismicity from the injection of wastewater Written for environmental scientists, geologists, engineers, regulators, city planners, attorneys, foresters, wildlife biologists, and others, Environmental Considerations Associated with Hydraulic Fracturing Operations offers a comprehensive resource to the complex environmental and communication issues related to fracking.

By measuring the direction and intensity of magnetism in rocks of different ages, a record of the Earth's magnetic field in the past can be obtained. This 1994 book deals with the particular case of reversals of the Earth's magnetic field. These have played a major role in the development of plate tectonics and in establishing a geological time scale. The magnetism of rocks is discussed in some detail with a warning of possible misinterpretations of the record. Observational results and theories are reviewed with special attention to the structure and geometry of the transition field. Changing conditions at the core-mantle boundary, their effect on reversals, the generation of plumes and the possible correlation of reversals with tectonic changes, ice ages or mass extinctions are thoroughly discussed, including suggested periodicities in the reversal record and in other geophysical data.