The use of remote sensing data increases the efficiency of field mapping, especially in areas with difficult access or where geologic fieldwork is expensive or hazardous. This study presents a newly developed software tool for interactively mapping and measuring the spatial orientation (i.e., dip angle and dip direction) of finite planar geologic structure from digital elevation models (DEMs). The orientations of planar data (e.g., sedimentary bedding or fault planes) are derived by approximating a virtual plane to the intersection of the planar feature with the DEM topography. To increase the informative value of the DEM, satellite images can be draped onto the topographic data set. The software tool was tested in the Zagros fold and thrust belt, northeast of Erbil (Kurdistan, northeast Iraq), where the stratigraphy has been deformed into subcylindrical fold trains. Computed orientations have been compared with actual dip angles and directions measured in the field. Under favorable conditions (moderately dipping planes, strong competence contrast between stratigraphic boundaries, intersection with a rugged topography, low vegetation), statistical comparison of computed data with the field measurements demonstrates that the spatial data set can be reproduced from the DEM within an average error of approximately 10°. The strength of the method is demonstrated by integrating field data with computed values from inaccessible areas, resulting in a reasonably well-constrained balanced geologic cross section.

You do not currently have access to this article.