What is economic geology? It may be defined as the study of geological bodies and materials that may be useful to mankind. The materials included are fuels, metallic and non-metallic minerals, rocks and water. This book will exclude considerations of water and building materials, and will concentrate on ores and fuels.

Some people may say that economic geology is a subdiscipline within the geological sciences, but this is not strictly correct, for it is unlike other su}?disciplines, such as palaeontology, igneous petrology, structural geology, and so on, which all go to make up the science of geology, for each of these can exist independently. Economic geology cannot exist as a separate discipline, for it has to be based on the broad spectrum of the geological sciences.

Economic Geology is an important branch of Geology which deals with different aspects of economic minerals being utilised by mankind to fulfill his various needs. The economic minerals are those which can be extracted profitably. The subject provides detailed knowledge of r'l these minerals, like their origin, process of formation, mutual relations and time sequence, control of localisation, metallogemc epoch and province, and classification, besides their mineralogy, uses, modes of occurrence, geological and geographical distribution, reserves, production and all other related facts. <...>

The first edition of this book appeared at the end of 1942. Since that time war and post-war readjustment has forcibly demonstrated the extent to which the materials of the mineral kingdom constitute the backbone of industrial life and peace-time economic development of nations. Former bountiful supplies now show serious depletion, and nations of the world are looking farther and farther afield for those miiieral supplies necessary to their subsistence. This book deals with' such mineral deposits, how they are formed, what they are, how and where they occur, and what they are used for. Its chief purpose is as a textbook, designed both for elementary and more advanced courses. The first edition was in demand also as a source of information to all those interested in mineral deposits and in the mineral industry. <...>

Во время прошлых землетрясений было выяснено, что колебания грунта на мягких участках почвы в целом больше, чем близлежащих горных пород, в зависимости от местных грунтовых условий (например, Сид (Seed) и Идрис (Idriss), 1968). Такие усиления реакции грунта симулировались с помощью нескольких компьютерных программ, в которых принимались упрощенные грунтовые условия, такие, как горизонтальные слои грунта бесконечной протяженности.