The ammonites collected from the upper 350 feet of the 600 feet of the Shelikof Formation exposed near Chignik Bay apparently represent two stratigraphic levels based on comparisons of the taxa present with those found elsewhere on the Alaska Peninsula (See Prof. Paper 836, fig. 6 on page 12). Those collections containing PSEUDOCADOCERAS GREWEINGKI (Pompeckj) have been found elsewhere on the peninsula only in the middle member of the Shelikof Formation. Those containing P. PETELINA (Pompeckj) in association with CADOCERAS COMMA Imlay and C. cf. C. GLABRUM have been found elsewhere on the peninsula only in the highest part of the lower member. Those containing only P. PETELINA could represent either the highest part of the lower member or any part of the middle member. By comparison with the sequence west of Cook Inlet the beds containing PSUEDOCADOCERAS GREWINGKI in association with CADOCERAS COMMA could represent the upper part of the Tonnie Siltstone Member or any part of the overlying Paveloff Siltstone Member. However, the presence of an ammonite resembling C. GLABRUM suggests that the beds are not younger than the Tonnie Siltstone Member.

The age of the upper 365 feet of the Shelikof Formation near Chignik Bay based on comparisons with the ammonites found elsewhere in southern Alaska (See Prof. Paper 836, fig. 8 on p. 14) is mostly of early Callovian age but could be partly of early middle Callovian age. Apparently the lowest ammonites collected near Chignik Bay are younger than the INISKINITES bearing beds west of Cook Inlet, which beds are now assigned to the late Bathonian on the basis of recent studies in Canada and Oregon.

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Brief statement of problem and remarks (from collector):
This is the southernmost occurrence of the Shelikof Fm. on the Alaska Peninsula. The rocks are exposed only in one small area at base of thrust plate and will extend the known range of the ammonites.