A NEW GEOLOGICAL SECTION MEASURING AND MAPPING METHOD:POINT COORDINATES METHOD

Geological section measuring and mapping is a necessary task for regional geological survey; however, the traditional geological section measurement, which is based on tapeline together with compass, has many limitations such as visual conditions, tapeline bending, manual measurement error and second projection defects. In order to improve the quality and efficiency of geological section measurement, on the basis of the previous methods, through the practice of a number of different types of geological survey projects, a new geological section measuring and mapping method using point coordinates is presented in this paper. The key points of the method include (1) Using GPS to obtain terrain control points, as well as three-dimensional coordinates in stratification, sampling, production, occurrence and other positions. (2) A series of formulas are developed, based on which parameters like horizontal distance between points, altitude difference, azimuth angle and slope angle can be calculated according to three-dimensional space coordinates of each point in order to do the mapping. The point coordinates method has two main advantages:(1) Digitization of measurement data is realized by the change from manual measurement to automatic measurement, and there is no need for tape line. (2) The facts that the end point of the tapeline does not coincide with the actual end point can be avoided. (3) It is convenient for field review because each layering point has a GPS coordinate.The case and practice have proved that the point coordinates method is superior to the tapeline method. It is worthy of being widely used in practical application.