Abstract

Points made in this paper are: (1) curvilinears are probably as abundant as straight lines on most parts of the earth’s surface; (2) the aggregate of curvilinears and straight lines should be used for geologic interpretation; (3) curvilinears and lineaments should be compiled in steps from separate images, combinations of images, and imagery from different seasons; (4) intersections of all lines, straight and curved, can be plotted as a guide to fracturing; and (5) some curvilinears can be used to locate associated straight geologic features such as faults. Although other workers have noted the presence of arcs, circles, and other curvilinears on the earth’s surface, most of these have been associated with circular landforms such as domes, basins, volcanic structures, or impact craters. Many curvilinears have been regarded as geologic curiosities. With the availability of repetitive coverage with the Earth Resources Technology Satellite (ERTS) imagery, it is now possible to map enough curvilinears in almost any area to change arcs and circles from geologic curiosities to indicators of geologic structure.

Techniques are discussed for using different graytone thresholds and image enhancing to recognize subtle lines on images. Lines from different ERTS bands, combinations of bands, and imagery from different seasons can be superposed on transparent overlays to maximize the number of straight and curved lines in an area. Techniques for mapping areas of maximum rock fracturing are discussed, including computer techniques. Centers of intense rock fracturing, as mapped from ERTS - 1 imagery, coincide rather well with two Nebraska oil fields. Other applications of this technique would be in mineral exploration, ground water, and selection of construction sites.