THREE-DIMENSIONAL MAPPING OF OUTCROP GEOLOGY: CASE STUDIES IN SILICICLASTICS, CARBONATES, AND STRUCTURE

The collection of three-dimensional data from outcrops is an important research goal for many diverse groups. It has become increasingly clear that 1D and 2D data are insufficient to completely describe outcrops from a fluid-flow or process-oriented perspective. There are many ways to approach this problem, most involving new and emerging technology. Three-dimensional data can be collected from the outcrop using conventional surveying instruments such as total stations, high-precision Real-Time Kinematic GPS systems, photogrammetry, ground-based laser ranging, satellite or airborne remote sensing platforms, and any combination of these techniques. Our goal is to present several of these techniques as applied to specific outcrop examples to illustrate which are best used in certain circumstances, and how different techniques can be integrated to solve specific problems. We will illustrate that accurate three-dimensional data can be extracted at various scales from various types of outcrop exposures; from those that are clearly 3D to those that are seemingly 2D. We will also present examples of data collected for specific problems in both siliciclastic and carbonate depositional systems. In stratigraphy, three-dimensional data collected from outcrops can be used to accurately describe facies relationships and geometries. These data can be used to generate 3D geologic models as direct input for fluid flow simulations, and can also be used as real-world examples to test predictive process models, or as inputs into inverse models. In structural geology, the three-dimensional problems are more obvious and often more complex. Three-dimensional data extracted from the outcrop can be used to construct faulted framework models, which can be used to generate fluid flow models or to aid in the development of predictive models. Structural data can also be used to undeform 3D stratigraphic data. Specific examples of 3D data collected for the purposes of generating structural models will be shown.