The fi rst three parts of the section address the development of soil mechanics and geotechnical engineering as a distinct discipline over the past 80 years or so. Chapter 2 Foundations and other geotechnical elements in context - their role explains the importance of foundations and structures built in or of the ground within civil engineering and construction, and the need for a formal and holistic geotechnical engineering design process. Chapter 3 A brief history of the development of geotechnical engineering gives a history of the development of geotechnical engineering at the borderline between science and art, with the latter defi ned by Terzaghi in 1957 as a ‘mental processes leading to satisfactory results without the assistance of step-for-step logical reasoning’. This is refl ected in the ‘geotechnical triangle’, described in Chapter 4 The geotechnical triangle, which emphasises the essential elements of successful geotechnical engineering as understanding the ground, material properties and relevant precedence (well-winnowed experience), connected by an appropriate model for analysis. <...>

Igneous and metamorphic petrology in the last decades of the twentieth century exploded into a broad, multifaceted, increasingly quantitative science. Advances in physical and field petrology and geochemistry have forever changed our thinking about the origin and evolution of magmas, their dynamic behavior, and the way in which they are intruded and explosively extruded. Developments in geochronology, quantitative evaluation of the role of heat and fluid transfer in crustal rocks, and new field discoveries have impacted our understanding of the evolution of metamorphic systems and their dynamic interaction with tectonic processes. Geophysics and mineral physics have provided new insights into the nature of the convecting mantle and its role as a giant heat engine driving magmatic and metamorphic processes. New tools of all kinds allow new ways of gathering petrologic data, while phenomenal developments in computers and computer software permit data to be stored, processed, and modeled in ways unimaginable as recently as a couple of decades ago.

The Carlin trend contains the largest concentration of Carlin-type gold deposits in the world. Two major controversies about these giant gold deposits have been their age, which is now firmly established as Eocene, and the source of heat, fluids, and metals, which remains debated. We present data that demonstrate an intense period of Eocene magmatism coincided in time and space with deposit formation and was arguably the primary heat source. Geologic studies over the last 40 years have emphasized the stratigraphy and structure of Paleozoic sedimentary rocks, which are the major ore hosts. However, four igneous episodes affected the Carlin trend, in the Jurassic, Cretaceous, Eocene, and Miocene. A Jurassic diorite-granodiorite laccolith and related dikes were emplaced at about 158 Ma in the northern Carlin trend. A Cretaceous granite intruded the northcentral part of the trend at 112 Ma. Abundant Eocene dikes intruded along most of the trend and were accompanied by lavas in a large volcanic field along the southwest edge of the trend between ~40 and 36 Ma. Miocene rhyolite lavas erupted just west of and across the southern part of the trend at ~15 Ma.

Igneous rocks, apart from those few which are wholly or partly glassy, are composed of minerals and a knowledge of these minerals therefore is one logical starting point for study. Indeed the microscopic determination in thin sections of the content, abundance, and textural relations of component minerals remains, as it was for classical petrographers, the most widely used tool in the investigation of igneous rocks