To assist the determination of which of these tonal 
features (linears) might also in fact be faults other re- 
mote sensing data was employed. Other products used in this 
investigation included SLAR imagery, Figure 3, and high 
altitude aerial photography. Figure 4 shows a comparison 
of the Landsat, SLAR, and Hi-altitude photo lineaments. 
The area within the square is some 20 x 20 miles on a 
side and all the lineaments have been transferred to a 
Landsat scene which was used as a base. Appropriate geo- 
logic maps were used and indicates that many linears were 
in fact fault traces or extensions of mapped faults. 
In areas of sedimentary deposition on older basement 
structures which have been reactivated in the past, 
structural trends may be reflected in the overlying sedi- 
ments as drainage patterns or subtle linears. Some of the 
features identified in Figures 1 and 2 may have such an 
origin. While the exact mechanism responsible for this 
surface expression is obscure, lineament mapping from 
satellite imagery appears to be applicable to identifying 
major structural trends. Since these trends appear to be 
associated with the basement underlying thick sedimentary 
deposits, such lineament analysis provided a rapid and in- 
expensive method for aiding the site evaluation. 
The ultimate goal in our remote sensing studies of 
geologic features for nuclear power plant siting is the 
development of a chronology of deformation. Dominant 
linear trends which persist through geologic history can 
have several periods of movement associated with them. 
The sense of movement will vary, depending on the orien- 
tation of the stresses at any particular time. Analysis 
of the sequence of movement and identification and orien- 
tation of the youngest controlling lineament identified 
as a fault takes on added significance in light of the 
present day stress field and is important to site safety 
considerations.