Abstract: 3D geological modeling and visualization is a key technique in digital mine and is of great importance to the mine production, geoscienctific analysis and resource assessment.With the drill-hole information and geological section map as the basic data, the paper proposes a section-based 3D geological modeling process, which is used to establish the facial model of the geological body and the volumetric model of its corresponding geological blocks so as to finally realize a “section-TIN-block” facial-volumetric mixed modeling and visualization of the scientific calculation.The key algorithm involved in the modeling is studied; the method “cut-and-sew” is proposed for solving the 3D reconstruction problem of adjacent section contour lines which are greatly different from each other in the number of the shape and vertex; and the triangulation algorithm for polygon with islets is studied for solving the modeling of complex geological body with stones and holes.

Key words: 3D geological modeling, “Section-TIN-block&rdquo, model, Visualization, Digital mine, Cross section, Facial-volumetric mixed modeling