Fault Patterns in Southeastern Alaska

Geology of the Craig quadrangle, Alaska

“…These include the Heceta-Tuxekan Islands area (Eberlein, written communication, 1949), part of Baker Island (Robinson, 1946), the Hetta Inlet area (Kennedy, 1953;Wright, 1915), Kasaan Peninsula (Wright, 1908, p. 78-97,116-126;1915;Warner and others, 1960), and Mount Burnett (Kennedy and Walton, 1946). The work of Twenhofel and Sainsbury (1958) on the pattern of faults and lineaments in southeastern Alaska strengthens the photogeologic interpretation of a similar pattern in Craig quadrangle. These reports and many others contain useful data as brief references, summations of previous information, or annual progress reports on mines, quarries, and prospects.…”

“…The pattern of major lineaments related to faulting southeastern Alaska has been discussed by Twenhofel and Sainsbury (1958) and analyzed with respect to known field relations. They describe the well-defined major lineaments as striking northward and northwestward.…”

Geologic investigations of proposed powersites at Baranof and Carbon Lakes, Baranof Island, Alaska

“…The Chatham Strait fault is a split or extension of the Denali fault, a great arcuate fault that can be traced from Lynn Canal to Bristol Bay (St. Amand, 1957). Twenhofel andSainsbury (1958, p. 1435) believe that the Denali fault and probably the Chatham Strait fault are active along their entire length and have been active, at least since early Tertiary.…”

“…Twenhofel andSainsbury (1958, p. 1435) include this fault as a segment of a large fault, which they call the Clarence Strait lineament and which extends from Clarence Strait to Cross Sound. The Clarence Strait fault may intersect the active Fairweather fault that lies on the southwest side of the Fairweather Range.…”

Geologic reconnaissance of possible powersites at Tyee, Eagle, and Spur Mountain Lakes, southeastern Alaska

“…Earthquake epicenters in southeastern Alaska and coastal British Columbia appear to roughly parallel major linear topographic trends, the largest of which include Chatham Straii>-Lynn Canal and the west coasts of Baranof, Chichagof, and the Queen Charlotte Islands (St. Amand,195Y). These lineaments are considered to be traces of active fault zones (Twenhofel and Sainsbury, 1958). One of the major lineaments is the Coast Eange lineament described previously.…”