Reference Detail of

Report on Referred Fossils
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Stratigraphic range: Lower Jurassic
Kinds of fossils: Mollusks
Quadrangle or area: Talkeetna C-6, Alaska
Shipment No.: A-75-24M
Referred by: Reed, Bruce
Report prepared by: Imlay, Ralph W.
Date: 10/03/1975

The fossils from localities 75AR38A and 39 are definitely Lower Jurassic as shown by the presence of arietitid ammonites and the pelecypod Weyla. Also, the presence of Coroniceras at locality 75AR39 shows that the beds at that place are definitely lower Sinemurian.
The fossils from locality 75AR38C include belemnites preserved in a brown sandstone matrix and Buchia crassicollis solida preserved in a limestone matrix. Apparently the fossils from two different beds got mixed just as they did last year (locs. 74ARA68B and C). Please ask Dave Jones to check the fossils from locality 75AR38B for possible mixing.
The ammonites from Mesozoic loc. 16229 near Partin Creek (see description in Prof. Paper 801, p. 22) were collected by Elmer Bedager, a prospector, and submitted to the Survey geologist Ralph Tuck in Alaska during the field season of 1932. The general area was described by S. R. Capps in 1919 (USGS Bull. 692, p. 207-232). Locality 16229 is in the Healy (A6) 15 min. quad., a copy of which will be sent to Dave Jones for field use in 1976. The collection contains about 15 specimens of undeformed ammonites that show the features of Arnioceras very well. In addition it contains one fairly smooth, evolute ammonite suggestive of some member of the Juraphyllitidae, one undeformed Pleuromya and several fragments of Pectinids. Evidently the Jurassic at that place is not metamorphosed or deformed.

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75AR38A (Mesozoic loc. 30907) , Talkeetna , Brown ferruginous sandstone 150 feet below first Buchia-bearing limestone bed. Elev. 5850 ft. 3.5 miles west of Shellabarger Pass, Central Alaska Range.
Arietitid ammonite
Weyla sp.
Oxytoma sp.
Ostrea sp.
Entolium sp.
Eopecten? sp.
Brachiopods undetermined
75AR39 (Mesozoic loc. 30908) , Talkeetna , Brown siltstone and sandstone, ferruginous. Elev. 6100 ft. 5 miles southwest of Shellabarger Pass, Central Alaska Range. [D.L. Jones, 1975. Altitude 6,100 ft (1,859 m), 5 miles (8 km) southwest of Shellabarger Pass, lat 62 deg. 30'20" N., long. 152 deg. 55'59" W., Talkeetna (C-6) quadrangle, southern Alaska. Unnamed beds. Early Sinemurian. (description from Imlay, 1981, p. 27)]
Coroniceras sp.
Oxytoma cf. O. cygnipes Phillips
75AR38C (Mesozoic loc. 30909) , Talkeetna , Second outcrop of Lower Jurassic brown ferruginous sandstone. Elev. 5475 ft. 3.5 miles west of Shellabarger Pass, Central Alaska Range.
Belemnites in brown sandstone matrix
Buchia crassicollis solida (Lahusen) in a gray limestone matrix