Alaska Paleontological Database

Reference Detail

Report on Referred Fossils

Stratigraphic range:

Upper Jurassic

Kinds of fossils:

Mollusks

Quadrangle or area:

Iliamna C-2, B-3

Shipment No.:

A-61-32M

Referred by:

Detterman, Robert L.

Report prepared by:

Imlay, Ralph W.

Date:

11/13/1961

***
Brief statement of problem and remarks (from collector):
(from letter to Ralph Imlay, dated November 13, 1961)

I will be sending you five collections of fossils from the Naknek Formation in the near future. They are all from the siltstone overlying the Chisik Member. The collections are small and most are only fragments. This was the worst year I have ever had as far as fossil collecting goes. The part of the Naknek that we saw was always in fault contact with the older rocks along the Bruin Bay Fault, so we never had a chance to check the lower contact of the formation for an unconformity.

User Note module to be added

61ADt44 , Iliamna , Lower Naknek formation; massive siltstone about 200-300 feet above contact with Chisik Member; along shore of Cook Inlet between Ursus Cove and Iliamna Bay; 0.6 mile N. 42 deg. E. of south tip of Ursus Head. Coords. 6.0-4.03; C2 quad; 59 deg. 33'28" N., 153 deg. 34'50" W. [Note by R.B. Blodgett, the 8 on 28" Lat. is indistinct, may also be 23"]. Detterman and Reed (1980, p. B39 - Table 2) provide the following information: Fortification Bluff area. Snug Harbor Siltstone Member of Naknek Formation. Shown as locality 5 on Plate 1]

belemnites

one guard probably belongs to Pachyteuthis

61ADt45 (Mesozoic loc. 28520) , Iliamna , Lower Naknek formation; about 200 feet above Chisik Member; massive siltstone with few thin sandstone interbeds. Shore of Cook Inlet; 1.22 miles N. 30 deg. E. of tip of Ursus Head; Coord 6.21-4.67; C-2 quad; 59 deg. 34' N., 153 deg. 34'30" W.; USGS Mesozoic loc. 28520, 1.22 miles N. 30°E. of tip of Ursus Head; Mesozoic loc. 28521, 0.22 mile N. 62° E. of tip of Ursus Head. Ursus Cove on west side of Cook Inlet. Buchia concentrica (Sowerby). (description from Imlay and Detterman, 1973, p. 25); USGS Mes. Cat: 28520. (61AD-45). Upper Jurassic - Lower Naknek fm. about 200' above Chisik Mbr. Massive siltstone with few thin sandstone interbeds. Shore of Cook Inlet; 1.22 miles N. 30° of the tip of Ursus Head; Coords. 6.21 & 4.67 C-2 quad; 59°34' N., 153°34'30" W. Coll. by R.L. Detterman, 1961. Alaska]

belemnites

Phylloceras sp.

Buchia concentrica (Sowerby)

61AHe55 (Mesozoic locl. 25821) , Iliamna , Lower Naknek formation; massive siltstone about 300 feet above Chisik Member; Shore of Cook Inlet; 0.22 miles N. 62 deg. E. of tip of Ursus Head; Coords 5.80-3.71; float; C-2 quad; 59 deg. 33'18" N., 153 deg. 35'15" W. [Detterman and Reed (1980, p. B39 - Table 2) provide the following information: Fortification Bluff area. Snug Harbor Siltstone Member of Naknek Formation. Shown as locality 5 on Plate 1]; USGS Mesozoic loc. 28520, 1.22 miles N. 30°E. of tip of Ursus Head; Mesozoic loc. 28521, 0.22 mile N. 62° E. of tip of Ursus Head. Ursus Cove on west side of Cook Inlet. Buchia concentrica (Sowerby). (description from Imlay and Detterman, 1973, p. 26); [USGS Mes. Cat: 28521 (61-AHe-55). Upper Jurassic - Lower Naknek fm.; Alaska. Massive siltstone about 300' above Chisik Mbr., shore of Cook Inlet; 0.22 miles N. 62° E of tip of Ursus Head; Coords. 5.80 -3.71; float; C-2 quad; 59°33'18" N., 153°35'15" W. Coll. by R.L. Detterman - 1961]

belemnites

Buchia concentrica (Sowerby)

61AHe56 , Iliamna , Same as 61AHe55; float

belemnites

61ADt94 , Iliamna , Lower Naknek formation; massive brownish-gray siltstone with beds of grit about 400-500 feet above Chisik Member; Cove at southeast corner of Bruin Bay - inside bay; 1.3 miles S. 8 deg. E. of point at entrance to Bruin Bay; coords 6.3-9.45; B-3 quad; 59 deg. 21'30" N., 153 deg. 59' W.

belemnites