Rock outcrops (fig. 2) are scarce except along the shoreline and above timberline , 
which ranges from about 500 feet to more than 1,500 feet above sea level. In aerial 
view (fig. 4) the structural pattems are evident, even In the heavily vegetated areas. 
These structural patterns are believed to hold some of the answers to possible new 
discoveries of mineralized areas in this former copper-mining district. 
Figure 4, == Aerial view of Prince William Sound area, Alaska, showing 
structural patterns in timbered areas. 
A quite different type of terrane (fig. 5) Is found in the northern part 
of Alaska where some 60,000 square miles has been studied and mapped photo- 
geologically. This is an area of gently folded, locally faulted sedimentary 
rocks that may be petroleum bearing. Throughout most of the area, outcrops 
are scarce except along major streams, but topographic and vegetation changes 
(fig. 5) clearly reflect the underlying strata in many places. Thus geologic 
structures may be delineated and even contoured.