Geological mapping and fold modeling using Terrestrial Laser Scanning point clouds: application to the Dents-du-Midi limestone massif (Switzerland)

Abstract

Geological mapping in vertical rock faces is extremely challenging because of access difficulties and limited possibilities of recognition, localization and measurement of features at large distance with traditional tools. Moreover, vertical areas can be of primary interest since they often display good quality outcrops and relevant geological information. This study focuses on the detailed remote identification of rock types and fold structures using intensity values acquired by Terrestrial Laser Scanning. A correction of the intensity is proposed proportional to the square of the range and to the cosine of the incidence angle. Furthermore, two methods of remote lithological mapping in 3D have been developed using a manual and a semi-automatic approach. Both delivered good results that are consistent with the spatial distribution of rock-types and allowed us to generate an accurate 3D lithological map of Dents-du-Midi massif (Valais, Swiss Alps). The bedding orientation near the hinge of a Km scale fold was measured on LiDAR data in order to define the fold axis. Then, the result was used to build a model of the hinge in 3D.

Harnessing the power of immersive virtual reality - visualization and analysis of 3D earth science data sets

“…This allows the user to distinguish different geological formations (e.g. Matasci et al 2017). In this case, the yellow to green are older lava flows exposed in the cave walls that have a thin alteration rind on them.…”

MATLAB Virtual Toolbox for Retrospective Rockfall Source Detection and Volume Estimation Using 3D Point Clouds: A Case Study of a Subalpine Molasse Cliff

“…3D point clouds are commonly used in different scientific domains and in geosciences. In geosciences, the use of point clouds mainly focuses on capturing outcrop geometry [1], mapping geological layers [2], or investigating surface morphological changes [3,4]. In the topic of natural hazards, point clouds are frequently used for mapping landslides and monitoring topographic changes resulting from rockfall activity or mass movement [5].…”

“…The points representing the conditions in Equations (1) and (2) are merged for each neighborhood as one set of points belonging to a rockfall source. The result is spatially distributed points that form clusters corresponding to rockfall sources and isolated points associated with noise ( Figure 1).…”

Geostructural and Geomechanical Study of the Piastrone Quarry (Seravezza, Italy) Supported by Photogrammetry to Assess Failure Mode

“…The acquisition of three-dimensional (3D) data of the terrain surface is now obtained with a high accuracy, in less time and over a wider area thanks to the evolution of satellite and remote sensing imaging technologies. This progress has also changed the way to collect and interpret information about the geostructural setting of large areas [26][27][28][29][30] or the structure of rock mass for the stability assessment [31][32][33][34][35][36][37], with the great advantage of allowing for the survey of high inaccessible steep slopes in safe conditions. To become a real alternative (both in terms of productivity as well as accuracy) to a traditional survey, interactive or automated software tools are necessary, to allow the efficient selection on the point cloud of elements of interest (i.e., discontinuity planes and traces, etc.…”