Field work, supplemented by laboratory studies, is a cornerstone for the geological sciences. This volume provides an introduction to general field work through selected topics that illustrate specific techniques and methodologies. One hundred and twenty-three main entries prepared by leading authorities from around the world deal with aspects of exploration surveys, geotechnical engineering, environmental management. field techniques, mapping, prospecting, and mining. Special efforts were made to include topics that consider aspects of environmental geology in particular those subjects that involve field inspections related to, for example, the placement of artificial fills, sediment control in canals and waterways, the geologic effects of cities, or the importance of expansive soils to environmental management and engineering. In addition, some widely ranging topics dealing with legal affairs, geological methodology, the scope and organization of geology, report writing, and other concepts, such as those related to plate tectonics and continental drift, provide a necessary perspective to the arena of field geology.

Geologic maps supply a wealth of information about the surface and shallow subsurface of the earth. The types of materials that are present in a location and the three-dimensional structure of the bedrock both can be gleaned from a clearly prepared geologic map. Geologists, civil and environmental engineers, land-use planners, soil scientists, and geographers commonly use geologic maps as a source of information to facilitate problem solving and identify the qualities of a region. Maps reveal the position of many types of natural hazards, indicate the suitability of the land surface for various uses, reveal problems that may be encountered in excavation, provide clues to the natural processes that shape an area, and help locate important natural resources. Suitable for lab courses in structural geology as well as field geology work, Spencer describes representative examples of features found on geologic maps and outlines procedures for interpretation and projection. Geometric techniques are explained using a step-by-step approach. Coverage of mapping methods includes tools that provide necessary data, such as Google Earth, GPS, GIS, LiDAR maps, drones, and aerial photographs. Challenging and engaging exercises throughout the text involve students in the mapping process and stimulate an appreciation of the extent and precision of information presented in geologic maps. Regional geology is an important component of lab and field mapping projects. As such, the Third Edition includes new maps of the Gulf of Mexico Coastal Plain, Rocky Mountain Front Range, Yellowstone region, Moab, Utah, Shenandoah National Park, and Hawai’i. A new chapter devoted to tectonic maps also broadens students’ exposure. Ed Spencer brings over 45 years of teaching experience to the text along with valuable insight and clarity into the interpretation and preparation of geologic maps.

Geologic maps: a few lucky geologists make them; many geoscientists, engineers, and planners use them; untold scores of people wonder what they are all about. Perhaps the most common question we are asked, those few of us who do make geologic maps, is, simply,“What is a geologic map?” This query is often followed by “What are geologic maps used for?,” “Hasn’t it been mapped before?,” and, if the person is really inquisitive, “What do all those lines, colors, and symbols represent?” It must be a puzzling sight - a lone geologist, often miles from the nearest road, looking at rocks, putting lines on a map or aerial photograph. One rightfully wonders what that person is doing. This pamphlet answers these questions and points out the value and many uses of geologic maps.