Reference Detail of

Report on Referred Fossils
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Stratigraphic range: Callovian & Oxfordian - Upper Jurassic
Kinds of fossils: Mollusks
Quadrangle or area: Ugashik quad., SW and NE of Wide Bay
Shipment No.: A-79-35
Referred by: Detterman, Robert L.
Report prepared by: Imlay, Ralph W.
Date: 08/31/1979

The fossils from locality 79ADt-129 are definitely of late early or middle Callovian age as shown by the presence of Pseudocadoceras and Cadoceras. The same age is suggested for locality 79ADt-128 as shown by the presence of a fragment resembling Pseudocadoceras.

A late middle Oxfordian to late Kimmeridgian age is shown by the presence of Buchia concentrica (Sowerby) at localities 79ADt-85, 79ACe-64 and 79ACe-73B. The presence of Buchia sp. at locality 79ACe-48A shows that the associated Phylloceras (Partschiceras) is not older than late middle Oxfordian. The specimen of Phylloceras (Partschiceras) at locality 79ACe-75 is identical with a species in the Naknek Formation that I am describing in an unpublished paper on Upper Jurassic ammonites from Alaska.


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Brief statement of problem and remarks (from collector):
The ammonites from the Shelikof Formation represent a considerable westward extendsion of the formation into an area of supposedly younger rocks. Identifications need to confirm age of units.
User Note module to be added
79ADt85 , Ugashik , Ugashik A-4 quad., sec. 20, T. 36 S., R. 49 W., lat. 57 deg. 03 min. 24 sec. N., long. 157 deg. 10 min. 50 sec. W., 6 miles south of south end of Needle Lake. Naknek Formation, upper part part, thin-bedded greenish-gray siltstone.
Buchia concentrica (Sowerby)
Gastropod undetermined
79ADt145 , Ugashik , Ugashik A-3 quad., sec. 12, T. 35 S., R. 48 W., lat. 57 deg. 10 min., 12 sec. N., longitude 156 deg. 54 min. 31 sec. W, 3.8 miles N. 50 deg. E. of Chiginagak Volcano, Naknek Formation, upper part of sandy member, thin-bedded, yellowish-brown sandstone and massive conglomerate.
Phylloceras sp.
79ADt128 , Ugashik , Ugashik C-3 quad., Sec. 5, T. 31 S., R. 46 W., lat. 57 deg., 31 min., 56 sec. N., long. 156 deg. 46 min., 41 sec. W., East shore of Lower Ugashik Lake 2 miles S. 10 deg. E. of south end of narrows between Upper and Lower Ugashik Lakes. Shelikof Formation, dark olive green silty sandstone.
Pseudocadoceras?
Belemnites
Pleuromya?
79ADt129 , Ugashik , Ugashik C-3 quad., Sec. 5, T. 31 S., R. 46 W., lat. 57 deg. 32 min. 20 sec. N., long. 156 deg. 46 min. 35 sec. W., east shore Lower Ugashik Lake, 1.6 miles S. 16 deg. E. of south end of narrows between lakes. Shelikof Formation, rusty olive green siltstone and silty sandstone.
Pseudocadoceras grewingki (Pompeckj)
Pseudocadoceras crassicostatum Imlay
Cadoceras cf. C. wosnessenskii (Grewingk)
79ACe48A , Ugashik , Ugashik A-4 quad., sec. 26, T. 36 S., R. 50 W., lat. 57 deg. 02 min. 10 sec. N., long. 157 deg. 15 min. 36 sec. W., 8.2 miles S. 24 deg. W. of south end of Needle Lake. Naknek Formation, hornfelsed gray siltstone.
Phylloceras (Partschiceras) sp. B
Buchia sp.
79ACe64 (Mesozoic loc. M7339) , Ugashik , Ugashik B-3 quad., sec. 8, T. 33 S., R. 46 W., lat. 57 deg. 20 min. 23 sec. N., long. 156 deg. 43 min. 15 sec. W. 7 miles S. 58 deg. E. of east end of Elizabeth Lake. Naknek Formation, brownish siltstone overlying massive conglomerate and sandstone with limestone lenses. (description from E&R report of Imlay, 8/31/79). [Ugashik (B-3) Quadrangle. Sec. 8, T. 33 S., R. 46 W. Latitude 57 deg., 20 min., 23 sec. N., longitude 156 deg., 43 min. 15 sec. W. t miles S. 30 deg. E. of south end of Lower Ugashik Lake. Naknek Formation. (description from Jones & Miller E&R report, 2/17/81)]
Buchia concentrica (Sowerby)
Ammonite fragment
79ACe73B (Mesozoic loc. M7343) , Ugashik , Ugashik A-4 quad., sec. 36, T. 36 S., R. 50 W., lat. 57 deg. 01 min. 53 sec. N., log. 157 deg. 13 min. 55 sec. W., 8.1 miles S. 18 deg. W. of south end of Needle Lake. Naknek Formation, gray siltstone. (description from Imlay E&R report of 8/31/1979) [Ugashik (A-4) Quadrangle. Sec. 36, T. 36 S., R. 50 W. Latitude 57 deg., 01 min., 53 sec. N., longitude 157 deg., 13 min., 55 sec. W. 5.4 miles S. 45 deg. E. of forks of Painter Creek. Naknek Formation. (from Jones & Miller E&R report of 2/17/81)]
Buchia concentrica (Sowerby)
79ACe75 (Mesozoic loc. M7353) , Ugashik , Ugashik A-4 quad., Sec. 30, T. 36 S., R. 49 W., lat. 57 deg. 02 min. 31 sec. N., long. 157 deg. 13 min. 22 sec. W., 7.6 miles S. 15 deg. W. of south end of Needle Lake. Naknek Formation, gray siltstone. (description from Imlay E&R report of 1979) [Ugashik (A-4) Quadrangle. Latitude 57 deg., 02 min., 31 sec. N., longitude 157 deg., 24 min., 06 sec. W. Head of west fork of Painter Creek forks. Naknek Formation (description from Jones & Miller E&R report of 2/17/81)]
Phylloceras (Partschiceras) sp. B.
79ACe88 , Ugashik , Ugashik (A-3) Quadrangle. Sec. 19, T. 34 S., R. 47 W. Latitude 57 deg., 13 min., 30 sec. N., longitude 156 deg., 54 min., 10 sec. W. 7 miles N. 25 deg. E. Chiginagak Volcano. Naknek Formation. (from Jones & Miller E&R report of 2/17/81) [No description given in Imlay E&R report of 8/31/1979.]
Ammonite fragment