Crust (geology) the crust. The boundary between the crust and mantle is conventionally placed at the Mohorovičić discontinuity, a boundary defined by a contrast in seismic velocity. The crust of the Earth is of two distinctive types: Because both continental and oceanic crust are less dense than the mantle below, both types of crust "float" on the mantle. This is isostasy, and it's also one of the reasons continental crust is higher than oceanic: continental is less dense and so "floats" higher. As a result, water pools in above the oceanic crust, forming the oceans. The temperature of the crust increases with
International Association for Engineering Geology and the Environment large projects and in the assessment and remediation of environmental issues, an update of the first statutes of the association was deemed necessary. The second statutes were approved by the general assembly in Kyoto (Japan) in 1992. A new definition of engineering geology was given, which reflected the experience collected during the previous 25 years and read as follows: "“Engineering geology is a science devoted to the investigation, study and solution of engineering and environmental problems which may arise as the result of the interaction between geology and the works and activities of man as well as to the prediction