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Reference
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| Title: |
Report on Referred Fossils
,
1978
(02/24)
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[Referred by J.T. Dutro, Jr. for R.E. Busch, Jr.] This report is based on 10 ammonoids from the upper argillite member of the Eagle Creek Formation, which includes siltstone layers. These fossils were collected by R.E. Busch, Jr., in 1974 and 1975 in the northwest measured section in the SE 1/4 NE 1/4 sec. 22, T. 15 N., R. 5 E., Mt. Hayes A-1 quadrangle, Alaska. The stratigraphic units and ammonoids are as follows: NW Siltstone - 1
URALOCERAS aff. U. INVOLUTUM (Voinova) 2 specimens
ALMITES aff. A. INVARIABILIS (Ruzhencev) 1 specimen
PARACELTITES sp. 2 specimens NW Siltstone - 7
PARAGASTRIOCERAS aff. P. ELLIPSOIDALE (Fredericks) 5 specimens Float
URALOCERAS sp. (fragment) 1 specimen |
| Report by: |
Mackenzie Gordon
, Jr.
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| Referred by: |
J. Thomas Dutro
, Jr.
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| | Age: | Artinskian (late Artinskian) |
| Formation: | Eagle Creek Formation |
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| Comment: | I have cited the affinities of these species to what appear to be the nearest Soviet species. PARAGASTRIOCERAS is extremely rare in the Texas section and URALOCERAS does not occur there. ALMITES is represented in Texas by distinctly different species. Representatives of these genera are common sections in the Soviet Union and in Arctic Canada. They are typical of rocks of Sakmarian and Artinskian age. However, the nearest species are Artinskian and mostly late Artinskian in age and would correlate with the Leonardian of Texas. The occurrence of PARACELTITES in this fauna is a puzzle as it is reported to begin in the Roadian section in Texas, which is transitional from the Leonardian to Wordian. I have a seen a PARACELTITES in the U.S. Natural History Museum collections occurring with typical Leonardian genera and regard this occurrence as very late Leonardian in age. Based on our present knowledge of the ammonoid succession, in various parts of the world, I would regard the upper argillite of the Eagle Creek Formation as late Leonardian (late Artinskian) in age. |
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