Attitudes of Structures

Abstract

While in field, the foremost thing a geologist should do is to note down the attitude of the rock or of any structure he/she intends to study. Attitude is a fundamental geometrical attribute that describes how a plane or a line is oriented on the surface of the earth. Attitude of any geological structure undoubtedly constitutes the starting point of any geological work of whatsoever nature. Measurement of the attitude of structures especially involves the concepts of direction, planar structures, linear structures, dip of beds, strike line, bearing and back-bearing. The direction system used by a structural geologist is either the conventional system or the azimuth system. The attitude of planar structures is defined by dip of beds and strike line, while those of linear structures by plunge and pitch. Bearing and back-bearing are used to locate any object or yourself in a topo-sheet. The most fundamental geological field instrument, clinometer compass, is described including its use in field. In general, the chapter provides the basic concepts of attitudes of structures, thus enabling a beginner to carry out independent field work in structural geology.