Portion of the "Geologic Map of Monterey 30'x60' Quadrangle and
Adjacent Areas, California". California Geological Survey CD
2002-04 -Click on image for a larger view- What is a Geologic
Map? A geologic map shows the distribution, relationship, and
composition of earth materials such as rocks and surficial
deposits (landslides, sediments) and shows structural features
of the earth (faults, folded strata). Special purpose maps or
derivative maps may only show details of faulting, landsliding,
mineralization or other geologic processes or features. A
geologist compiles the data to be presented on a map through the
use of field observations, aerial photographs, remote sensing
information, topographic information, soil survey information,
and laboratory analyses. The geologic data, in layer fashion,
are typically printed upon a base map. The base map may show the
topography, roads, rivers, or other cultural or natural features
in the map area. Modern maps are in digital form, extending
their usefulness in decisio