This book is designed primarily for university and college students taking geology as an honours course or as a subsidiary subject. Its aim is to lead the student by easy stages from the simplest ideas on geological structures right through the first year course on geological mapping, and much that it contains should be of use to students of geology at GeE 'A' level. The approach is designed to help the student working with little or no supervision: each new topic is simply explained and illustrated by text-figures, and exercises are set on succeeding problem maps.
This book provides a general introduction to the most important methods of geophysical exploration. These methods represent a primary tool for investigation of the subsurface and are applicable to a very wide range of problems. Although their main application is in prospecting for natural resources, the methods are also used, for example, as an aid to geological surveying, as a means of deriving information on the Earth’s internal physical properties, and in engineering or archaeological site investigations. Consequently, geophysical exploration is of importance not only to geophysicists but also to geologists, physicists, engineers and archaeologists. The book covers the physical principles, methodology, interpretational procedures and fields of application of the various survey methods.The main emphasis has been placed on seismic methods because these represent the most extensively used techniques, being routinely and widely employed by the oil industry in prospecting for hydrocarbons. Since this is an introductory text we have not attempted to be completely comprehensive in our coverage of the subject. Readers seeking further information on any of the survey methods described should refer to the more advanced texts listed at the end of each chapter. <...>
Geotechnical engineering is concerned with the application of civil engineering technology to some aspect of the earth, usually the natural materials found on or near the earth's surface. Civil engineers call these materials soil and rock. Soil, in an engineering sense, is the relatively loose agglomerate of mineral and organic materials and sediments found above the bedrock. Soils can be relatively easily broken down into their constituent mineral or organic particles. Rock, on the other hand, has very strong internal cohesive and molecular forces which hold its constituent mineral grains together. This is true for massive bedrock as well as for a piece of gravel found in a clay soil. The dividing line between soil and rock is arbitrary, and many natural materials encountered in engineering practice cannot be easily classified. They may be either a "very soft rock" or a "very hard soil." <...>
This text is designed for use in advanced undergraduate or early graduate courses in igneous and metamorphic petrology. The book is extensive enough to be used in separate igneous and metamorphic courses, but I use it for a one-semester combined course by selecting from the available chapters. The nature of geological investi-gations has largely shaped the approach that I follow.
Metamorph;c processes have been taking place on a massive scale throughout the Earth's history, and have affected the bulk of the rocks now present in the crust. Despite this, they are not as well understood as sedimentary or volcanic processes, because metamorphism can scarcely ever be observed directly, and the study of metamorphic rocks is instead based on observation, inference and logic, founded in relatively simplistic experimental studies and the basic principles of chemistry and physics
Groundwater is one of the most important renewable resources of the Earth and it occurs in many sites. Water in the form of rainfall and river or stream water penetrates the ground and moves through the pores of soils, rocks, and rock fractures and joints which are permeable enough to transmit water through them.
Science is only worth doing if it is interesting and fun. Hence the goal of a textbook is to interest students in a subject, convince them it is worth the effort required to learn about it, and help them do so. We have tried here to do all three. For seismology, these should be easy. It is hard to imagine topics more interesting than the structure and evolution of a planet, as manifested by phenomena as dramatic as earthquakes.
Diatoms are microscopic unicellular algae. Whatever the shape or size of the cell, it consists of the same basic parts: the nucleus, cytoplasm, plasma membrane, and the cell wall.
1.1. Structure of the Cell Wall
Emphasis in this Introduction is placed on the structure of the diatom cell wall, as opposed to the living contents, as, in the main, interest in diatom study is directed toward the structure and microstructure of the cell wall. Classification of diatoms and their identification pertinent to many areas of investigation is based on the structure of, and markings on the cell wall as revealed by the light microscope (LM). It is therefore imperative that the student of diatoms possesses a good basic knowledge of that structure and the terminology associated with it. <...>
The members of the olivine group crystallize with orthorhombic symmetry, the structures consisting of independent SiO4 tetrahedra linked by divalent cations in six-fold coordination. In the (Mg,Fe)-olivines there is complete solid solution between Mg2SiO4 (forsterite) and Fe2SiO4 (fayalite); similarly the (Fe,Mn)-olivines form a continuous series. Olivine is a major constituent of ultrabasic plutonic rocks and olivines of metamorphic origin occur principally in rocks of ultramafic composition, in impure carbonates and in iron-rich sediments.
