Geology information extraction from digital outcrop

Lidar (light detection and ranging) is a new technology for obtaining instantly the 3D digital outcrop information with a high density and high positional accuracy. This paper presents new methodologies for geology information extraction from digital outcrop based on ground‐based Lidar. A complete workflow is documented including data collection and processing, digital outcrop model building, geology information interpretation and extraction. At first, some exceptional exposed outcrops are scanned using a Leica HDS4400 long range 3D laser scanner in Xinjiang, China. Two types of data which include Lidar point cloud data and digital photograph are acquired in this field survey. The distance between Lidar points is about 10cm. Then, the elemental digital outcrop 3D model can be built, through calculating the TIN of Lidar point cloud. In the digital outcrop model, the stratigraphic boundaries or rock stratum boundaries can be extracted and the structural surface can be calculated by planar‐fitting method. In addition, the different lithologies of digital outcrop can be classified using supervised classification method. This high‐precision digital outcrop model technology based on Lidar can obtain more detailed geology information. This technology will be expended to more applications, such as constructing and visualizing complex 3D geology models, and reservoir modelling.