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Reference
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| Title: |
Report on Referred Fossils
,
1958
(01/22)
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Your collections from the Gaikema member of the Tuxedni formation are rather meagre for an age determination. They contain, however, the same varied pelecypod faunule as has been found in other seasons. The collections made by Hartsock, Kellum, Kirschner, Miller and others suggest that the Gaikema member is equivalent to the lower part of the European zone of Otoites sauzei and that the underling siltstone member is equivalent to the zone of Sonnina sowerbyi. The collections from the Fitz Creek member are excellent. They contain an assemblage that is correlated with the Otoites sauzei zone (See Arkell, 1956, Jurassic Geology of the World, p. 542). The only other item of interest is your assignment of collection 57ADt13 to the basal part of the Naknek formation. The ammonites present, however, belong to a compressed subgenus of Cadoceras that is common in the upper part of the Chinitna formation on Chinitna Bay and Tuxedni Bay. This part of the Chinitna formation probably disappears southward toward Iniskin Bay. At least the ammonites from the top of the Chinitna formation near Iniskin Bay are identical with those found in the middle part of the formation on Chinitna Bay. You may want to check this relationship next summer. |
| Report by: |
Ralph W. Imlay
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| Referred by: |
Robert L. Detterman
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| | Age: | Jurassic (Jurassic, lower part of Otoites sauzei Zone) |
| Formation: | Gaikema Sandstone (Gaikema member of Tuxedni formation) |
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| Comment: | Your collections from the Gaikema member of the Tuxedni formation are rather meagre for an age determination. They contain, however, the same varied pelecypod faunule as has been found in other seasons. The collections made by Hartsock, Kellum, Kirschner, Miller and others suggest that the Gaikema member is equivalent to the lower part of the European zone of Otoites sauzei and that the underling siltstone member is equivalent to the zone of Sonnina sowerbyi. |
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