PPT Slide
DEMs (digital elevation models) are regularly spaced grids of elevation data. The USGS supplies DEM files for most of the U. S. at scales of 7.5 minutes and 250,000 (~1 degree x 1 degree). 1 km x 1 km data is also available commercially. The advantage of using DEM data in this project is that often elevations reflect underlying geological features, such as faults or lithology.
In this study we are collecting and processing DEM data for the entire Michigan Basin, at 7.5 and 250,000 scales. Typically the data have to be decompressed, checked for elevation units and mosaiced together. Once this is done, the resulting images can be analyzed in various ways. We have applied a number of standard filters to the 1 km x 1 km Michigan data to extract lineations. Typical results are shown in the following slides.