We consider the structural position and petrology of eclogites in the North Kokchetav accretion-collision zone located north of the Kokchetav metamorphic belt formed by high- and ultrahigh-pressure rocks. In the Early Ordovician North Kokchetav tectonic zone, thin sheets of mylonite and diaphthoric gneisses with eclogites are tectonically conjugate with the volcanic and sedimentary rocks of the Stepnyak paleoisland-arc zone. Eclogites have been revealed at two sites of the North Kokchetav tectonic zone—Chaikino and Borovoe. The Chaikino eclogites formed at 800–850 °C and 18–20 kbar, and the Borovoe eclogites, at 750–800 °C and 17–18 kbar. Study of pyroxene-plagioclase symplectite replacing omphacite of the eclogites at both sites has recognized three stages of regressive magmatism: (1) formation of coarse-grained clinopyroxene-plagioclase symplectite at 760–790 °C and 11–12 kbar, (2) formation of fine-grained clinopyroxene-plagioclase symplectite at 700–730 °C and 7–8 kbar, and (3) amphibolization of pyroxene at 570–600 °C and 5–6 kbar. The Ar-Ar age of muscovite from the Borovoe mica schists hosting eclogites is 493 ± 5 Ma, which corresponds to the time of cooling of metamorphic rocks to <370 °C. Hence, the peak of high-pressure metamorphism and all recognized stages of retrograde changes are dated to the Cambrian. The geological data evidence that eclogite-schist-gneiss sheets were localized in the accretion-collision zone and became conjugate with sedimentary and volcanic rocks no later than in the Middle Ordovician

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. <...>

Wisely used, mineral resources create wealth, employment, a vital social and natural environment and peace. If the reverse of these conditions occurs only too often, illustrating the so-called “resource curse”, this should be attributed to the true perpetrators, namely irresponsible, weak or selfish leaders. This book, however, does not intend to provide rules for good governance. I wrote it as a broad overview on geoscientific aspects of mineral deposits, including their origin and geological characteristics, the principles of the search for ores and minerals, and the investigation of newly found deposits.