Sample Detail of
Sample: Sample No. 72AFr445 -- USGS No. 24951-PC
Locality: Field No. 72AFr445
Description: Eagle (D-3) quadrangle 1:63,360; near junction of center line between NE1/4 and SE1/4 and eastern boundary of sec. 8, T1N, R28E; elev. approx. 2550 ft., on spur west of Suter Creek Creek, a tributary of the Seventymile River; quartzitic rocks apparently in fault slice between amphibolite facies metamorphic rocks on the north and an igneous dike on the south. (description from Dutro E&R report) [Dusel-Bacon and Harris, 2003, p. 13 provide following description: Eagle D-3 quadrangle, lat 64o 55'45" N., long. 145o 04'33"W. Collected by H.L. Foster in 1972 and identified by J.T. Dutro, Jr.]
Location: Alaska Quadrangle: Eagle D-3
Township&Range: T1N R28E Section: sec. 8
Lat.: 64o55'45 "
Reference
Title: Report on Referred Fossils ,  1972 (10/18)
Report by: J. Thomas Dutro , Jr.
Referred by: Helen L. Foster
Age: Permian
Comment:The brachiopod molds and casts in this quartzitic rock indicate a Permian age, probably about the same age as the Tahkandit Limestone to the north. Although none of the species can be certainly identified, the generic assemblage suggests correlation with the lower sandstone unit of the Takhandit. This collection is most significant, as it documents the first occurrence of Permian rocks in the eastern Yukon-Tanana Upland, south of the Tintina fault zone.
Occurrence(s)
No. Group Name Qty Notes
1 Brachiopods Megousia sp.
2 Brachiopods Yakovlevia sp.
3 Brachiopods Anemonaria sp.
4 Brachiopods Spiriferella sp.
5 Brachiopods Neospirifer sp.
6 Brachiopods Tityrophora? sp.
7 Brachiopods punctate spiriferoid, indet.
8 Brachiopods brachiopod fragments, indet.

Title: New occurrences of Late Paleozoic and Triassic fossils from the Seventymile and Yukon-Tanana terranes, east-central Alaska, with comments on previously published occurrences in the same area ,  2003
Abstract - The discovery of several new fossil occurrences of late Paleozoic conodonts and radiolarians in the Seventymile and Yukon-Tanana terranes, and of Late Triassic conodonts in the Seventymile terrane in east-central Alaska, has prompted a reevaluation of other late Paleozoic and Triassic fossils reported in the same areas. The report, in 1995, of giant parafusulinids in the Seventymile terrane within the same stratigraphic interval that more than 20 years before produced poorly preserved Permian brachiopods helped place these beds in the middle Guadalupian and to position the terrane at tropical to subtropical latitudes near ancestral North America during the Middle Permian. .....
Report by: Cynthia Dusel-Bacon , Anita G. Harris
Age: Permian
Comment:

Shown as fossil locality 7 on Figure 2 (listed as fossil locality 7a on p. 13)

Terrane assignment, map unit, and sample lithology: Seventymile terrane. Unit Pq of Foster (1976); outcrops of unmetamorphosed brachiopod-bearing calcareous, fine-grained quartzitic sandstone and siltstone in fault slice between amphibolite-facies metamorphic rocks on the north and an igneous dike on the south. (from p. 13)

Age: Permian (from p. 13)

Remarks: J.T. Dutro, Jr., USGS (written commun. 1973), suggested correlation of these beds with the basal sandstone unit of the Takhandit Limestone at the type section. We believe that brachiopods are likely the same age as the fusulinids (middle Guadalupian), as the beds can be walked into the fusulinid locality and share the same lithology (see Steven, 1995) (from p. 13)

Exposures of unmetamorphosed brachiopod-bearing calcareous siltstone and fine-grained quartzite were discovered in a fault slice just south of the main part of the Tintina Fault system during geologic mapping of the Eagle quadrangle (Foster, 1976)(loc. 7, fig. 2; locs. 7a-7c, table 1), in the same fault slice from which the giant fusulinids were subsequently collected. Three brachiopod collections were made in 1972 and 1973, two of which were nearby and the third 2 km to the west. The brachiopods were preserved as casts and molds. (from p. 19)

We believe that because of the nearby discovery of giant parafusulinids (Stevens, 1995) in the same belt of rocks which contain the brachiopod localities, the age of the brachiopod beds in the Seventymile terrane is now updated and well constrained. The fusulinid locality is 2.5 km northwest of the westernmost brachiopod collection (locs. 6, 7, fig. 2; locs. 6, 7c, table 1) and could well be within the same stratigraphic interval. The fusulinids were discovered while field-mapping the brachiopod-bearing beds for several kilometers along strike, in blocks and boulders of brachiopod-bearing calcareous siltstone that were dug from beneath a thin layer of tundra (Stevens, 1995). Proximity, lithology, and both geologic and apparent stratigraphic position provide compelling evidence that, like the giant fusulinids, the brachiopod faunas first collected in the early 1970's are of middle Guadalupian (Wordian) age. (from p. 20)

Occurrence(s)
No. Group Name Qty Notes
1 Brachiopods Anemonaria sp. id. by J.T. Dutro, Jr.
2 Brachiopods Megousia sp. id. by J.T. Dutro, Jr.
3 Brachiopods Neospirifer sp. id. by J.T. Dutro, Jr.
4 Brachiopods Spiriferella sp. id. by J.T. Dutro, Jr.
5 Brachiopods Tityrophora? sp. id. by J.T. Dutro, Jr.
6 Brachiopods Yakovlevia sp. id. by J.T. Dutro, Jr.
7 Brachiopods Punctate spiriferoid, indeterminate id. by J.T. Dutro, Jr.