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Reference
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| Title: |
Report on Referred Fossils
,
1950
(01/16)
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Title: Report on Jurassic fossils from west side of Cook Inlet, southwestern Alaska, submitted by John A. Hartsock and Don Miller, December 15, 1949 (AF-49-10) Examination has been made of the collections of Jurassic fossils made in 1949 along the west side of Cook Inlet by Miller, Hartsock, and Grantz. There is no question concerning the age or stratigraphic position of most of the collections but a few require comment. ........ None of the other lots present any age problems. I hope to complete describing the Callovian ammonites early this spring and at that time will sent you a summary of conclusions. |
| Report by: |
Ralph W. Imlay
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| Referred by: |
John K. Hartsock
,
Don J. Miller
,
Arthur Grantz
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| | Age: | Jurassic (Jurassic, no further definitive age is given in E&R report) |
| Formation: | Tuxedni Group (Tuxedni formation, middle siltstone member) |
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| Comment: | Tuxedni formation Lot 48AMk146 (Mes. loc. 21303) contains well preserved specimens of Chondroceras (Defonticeras) which is characteristic of the middle siltstone member and has not been found in the Bowser member. It may occur in the Cynthia Falls sandstone member, as the sandstones at Fossil Point on Tuxedni Bay contain Chondroceras and appear to occupy the stratigraphic position of the Cynthia Falls. This stratigraphic assignment of lot 48AMr146 is at variance with that made last year on the basis of one specimen of Stephanoceras identical with a species that is common in the basal Bowser member. Possible explanations are that there was some mix-up of the collections, or that the species occurs rarely in the middle siltstone member. Anyway, I consider that this lot comes from below the Bowser. |
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