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The Earth is more than four billion years old. Its history is documented by the rocks that form the Earth’s crust, which lies beneath our feet and can be structurally complex in some places. The time that has elapsed since the formation of our planet is infinitely long when compared to the age of the human lineage, and several methods make it possible for us to measure geological time. The study of fossils—the remains of animals and plants preserved in sedimentary rocks—allows us to recognize the order of events that have formed the Earth.
Geophysical methods are based on studying the propagation of the different physical fields within the earth’s interior. One of the most widely used fields in geophysics is the electromagnetic field generated by natural or artificial (controlled) sources. Electromagnetic methods comprise one of the three principle technologies in applied geophysics (the other two being seismic methods and potential field methods). In this book the author presents both the foundations and the most recent achievements of electromagnetic geophysical methods in the framework of a unified systematic exposition.
The basic material for this book has been accumulated from time to time over the author’s working lifetime of about 40 years. The rules-and-pairs approach to Fourier transforms has been employed with good effect in a wide variety of problems, from pulse Doppler radar spectra to delay compensation, and antenna array patterns to efficient clutter simulation. It has been found generally easy and effective, quickly yielding useful results and allowing the user to see clearly the relationships between functions and transforms, waveforms and spectra, rather than losing sight of these in the complexities of integration. It seemed that the benefits of this approach should be better known, and the initial intention was to produce a technical note for use by the author’s colleagues and successors. However, the interest shown and encouragement given by Artech House have been gratefully received, and the opportunity to publicize the technique more widely has been taken. The support of Roke Manor Research in providing the facilities and freedom to write this book is gratefully acknowledged, as are the backing of C. J. Tarran and the reviewing of S. H. W. Simpson. The final acknowledgment is to the publisher’s reviewer, remaining anonymous, who provided encouragement and useful comments.
How much should a good spectroscopist know about Fourier transforms? How well should a professional who uses them as a tool in his/her work understand their behavior? Our belief is, that a profound insight of the characteristics of Fourier transforms is essential for their successful use, as a superficial knowledge may easily lead to mistakes and misinterpretations. But the more the professional knows about Fourier transforms, the better he/she can apply all those versatile possibilities offered by them. <...>
The scale invariance of geological phenomena is one of the first concepts taught to a student of geology. It is pointed out that an object that defines the scale, i.e., a coin, a rock hammer, a person, must be included whenever a photograph of a geological feature is taken. Without the scale it is often impossible to determine whether the photograph covers 10 cm or 10 km. For example, self-similar folds occur over this range of scales.
Carbon plays a fundamental role on Earth. It forms the chemical backbone for all essential organic molecules produced by living organisms. Carbon-based fuels supply most of society’s energy, and atmospheric carbon dioxide has a huge impact on Earth’s climate. This book provides a complete history of the emergence and development of the new interdisciplinary field of deep carbon science. It traces four centuries of history during which the inner workings of the dynamic Earth were discovered, and it documents the extraordinary scientific revolutions that changed our understanding of carbon on Earth forever: carbon’s origin in exploding stars; the discovery of the internal heat source driving the Earth’s carbon cycle; and the tectonic revolution. Written with an engaging narrative style and covering the scientific endeavors of about 150 pioneers of deep geoscience, this is a fascinating book for students and researchers working in Earth system science and deep carbon research.
The microstructure of a quartzite experimentally deformed and partially recrystallised at 900 °C, 1.2 GPa confining pressure and strain rate 10~ /s was investigated using orientation contrast and electron backscatter diffraction (EBSD). Boundaries between misoriented domains (grains or subgrains) were determined by image analysis of orientation contrast images. In each domain, EBSD measurements gave the complete quartz lattice orientation and enabled calculation of misorientation angles across every domain boundary. Results are analysed in terms of the boundary density, which for any range of misorientations is the boundary length for that range divided by image area. This allows a more direct comparison of misorientation statistics between different parts of a sample than does a treatment in terms of boundary number.
It is our impression that, over the last couple of decades, fluvial geomorphology and fluvial sedimentary geology have been developing in parallel, rather than in conjunction as might be expected. Though we tell our students that these are interdependent disciplines, perusal of the literature uggests there has been a failure of each domain to inform and recognize the needs of the other. Many facts have been collected, from both modem and ancient examples, yet our widerstanding of the sedimentary record of 1ivers eems not to have advanced significantly. It is still a struggle to map the architecture ob erved in the preserved rock record to the genetic components recorded from active modern rivers. Determination of the lateral extent and va1iation of lithofacies remains exceedingly problematic, especially in the subsurface.
The stratifi ed red beds of the Catskill Formation are conspicuous in road cut exposureson the Allegheny Plateau of north-central Pennsylvania. During this fi eld trip we will visit and explore several fossil localities within the Catskill Formation. These sites have been central to recent investigations into the nature of Late Devonian continental ecosystems. By the Late Devonian, forests were widespread within seasonally wellwatered depositional basins and the spread of plants on land from the late Silurian through the Devonian set the stage for the radiation of animals in both freshwater and terrestrial settings.