Orogens in space and time are the potential sources of information in understanding the mechanism of episodic global material circulation on a whole-mantle-scale. They represent the hallmarks of the interaction among lithospheric plates. The word “orogen” is derived from Greece (oros for “mountain,” genesis for origin). The term “orogen” or “orogenic belt” has been traditionally described as a mountain belt composed of different types of rocks or rock strata forming a complex of variable size, typically tens to hundreds of kilometres wide and several thousand kilometre long, later fragmented during younger geological time due to various processes (e.g., Miashiro, 1961). In modern terminology, an orogen can be defined as a major linear deformed zone, sandwiched between cratons with prolonged deformational history, repeatedly reactivated and associated with different events of magmatic pulses and metamorphic episodes in space and time (Dewey and Bird, 1970). An orogen or orogenic belt develops when a continental plate crumples and is pushed upwards to form one or multiple mountain ranges. This involves a series of geological processes called “orogenesis.” <...>

Atlas of igneous rocks and their textures A companion volume to the Atlas of Rock-forming Minerals in Thin Section, this full-colour handbook is designed to be used as a laboratory manual both by elementary students of earth sciences undertaking a study of igneous rocks in thin section under the microscope, and by more advanced students and teachers as a reference work. The book is divided into two parts — Part One is devoted to photographs of many of the common textures found in igneous rocks with brief descriptions accompanying each photograph. Part Two illustrates the appearance of examples of some sixty of the commonest (and a few not so common) igneous rock types; each photograph is accompanied by a brief description of the field of view shown. Nearly 300 full-colour photographs are included, and in many cases the same view is shown both in plane-polarized light and under crossed polars. A brief account of how thin sections can be prepared is included as an appendix. It is believed that the amateur geologist using these instructions will be able to make his own thin sections and, with the aid of a relatively simple microscope, enjoy the study of rocks in thin section.

Migmatites are spectacular, complex-looking rocks that can inspire, fascinate, or confuse geologists. All migmatites viewed in an outcrop represent the sum of a series of processes that acted in parallel, or sequentially, and the influence of various local factors (see the photographs in section A). In order to begin to understand the complexity and seemingly endless variety in migmatites, and to provide the reader context for the subject of this book, some of the key factors and processes that make individual migmatites the way they are should be outlined at the outset <...>

We were once emailed a long list of questions, arranged with paragraph‐sized spaces below each question for our  detailed answers and including photos of specific cored fractures, from a student starting to work on fractured cores. The questions were both basic and important, and included queries such as: Are both the slabs and butt of the cores used in fracture studies? How do you distinguish extension from shear fractures?