ABSTRACT
This chapter content presents a short review of geologic materials for the civil engineering student who may be in need of a little better background in geology, and a simple explanation of the theory of effective stress for the geology student not yet schooled in soil-mechanics and rock-mechanics aspects of engineering geology. Mass hydrogeologic characteristics are controlled by the discontinuities created by bedding planes, joints, fractures, and faults. A distinction based on geologic history may be made between two fundamental clay types, overconsolidated clays and normally-consolidated clays. Overconsolidated clays are those that have been subjected to greater-than-present overburden loads at some point in their geologic history. Igneous, sedimentary, and metamorphic rocks represent a basic subdivision of all rock types and display loosely-characteristic trends of hydrogeologic behavior. Soils form in response to the natural decay of these rocks by mechanical disintegration and chemical decomposition and may, in turn, become cemented, or otherwise lithified to form rocks once more.
