A Miner's-Eye View of Lineaments--What's Really Down There

Douglas C. Peters, Valois R. Shea

Lineaments (linear features) derived from aerial and satellite images and photographs have been used as guides to probable geologic structure for many years. These features delineated by topography or vegetation of an area generally are assumed to represent faults and other fractures that affect the near-surface material. Lineaments further have been assumed to extend to depth for the purposes of exploration for hydrocarbon and mineral deposits and for engineering site characterization.

Verification of the true origin of lineaments can be difficult to inconclusive using surface mapping or drill holes. Geophysical techniques (such as seismic) may provide too coarse a resolution to define the detailed structures which are expressed as lineaments. However, on-site examination of underground coal mine workings has allowed Bureau of Mines researchers to evaluate lineaments from the bottom up, a perspective generally unavailable to explorationists. Such examination provides an unobscured (by weathering, vegetation, etc) view of lineaments and their potential causes. Their intersection by mine workings and relationships to instability in those workings provides an unambiguous indication of their presence, width, and other parameters that may be important for mine planning a d exploration purposes. Examples of lineaments, both on the surface and underground in the eastern and western United States, will be discussed to provide conceptual models of their origin for those using lineaments as geologic tools.

AAPG Search and Discovery Article #91030©1988 AAPG Annual Convention, Houston, Texas, 20-23 March 1988.