Imnaitchiak Chert of Etivluk Group (AK*)
Pennsylvanian, Early* to Permian* to Triassic* to Jurassic(?)*
Kurupa Hills on southwest side of Kurupa River, in sec. 29, T. 12 S., R. 12 W., Umiat Prime Meridian, Killik River quadrangle, northern AK (Mull and others, 1987).
Reference section: on south side of hill along lower Akmalik Creek, in NE/4 sec. 27, T. 12 S., R. 10 W., Umiat Prime Meridian (Mull and others, 1987).
Alaska Northern region*
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