Sample Detail of
Sample: Sample No. 49AGz15 -- USGS No. Mesozoic loc. 21782
Locality: Field No. 49AGz15
Description: Naknek formation, from large blocks below basal Naknek, 0.8 to 0.9 miles west of Gull Island along south shore of Chinitna Bay, Iniskin Peninsula. (description from Imlay E&R report of 1/16/50)[Grantz transmittal sheet of Nov. 23, 1949 provides following description: "Cardioceras, from float below basal Naknek, (from large talus blocks) 0.8 to 0.9 miles west of Gull I. along south shore of Chinitna Bay."][Shown as locality 308 on Pl. 3 of Detterman and Hartsock, 1966 - Note by R.B. Blodgett: digitization of this point gives approx. lat. 59o 50'00" N., 153o 00'50" W.]; Arthur Grantz, 1949. South shore of Chinitna Bay. 1.3-1.4 km west of Gull Island at same place as Mesozoic loc. 11002. Naknek Formation, unnamed lower sandstone member, 61-76 m above base. Early Oxfordian. (description from Imlay, 1981, USGS PP 1190, p. 25); [USGS Mesozoic Catalogue: Orig. no. 49AGz15. Jurassic - Naknek. Same geographic location as (for?) 21775. Cardioceras, from float below basal Naknek (from large talus block) 0.8 to 0.9 miles west of Gull Island along south shore of Chinitna Bay. Coll. Grantz. 1949.]
Location: Alaska Quadrangle: Iliamna D-1
Lat.: 59o50'00 " Long.: 153o00'50 "
Reference
Title: Report on Referred Fossils ,  1950 (01/16)
Title: Report on Jurassic fossils from west side of Cook Inlet, southwestern Alaska, submitted by John A. Hartsock and Don Miller, December 15, 1949 (AF-49-10) Examination has been made of the collections of Jurassic fossils made in 1949 along the west side of Cook Inlet by Miller, Hartsock, and Grantz. There is no question concerning the age or stratigraphic position of most of the collections but a few require comment.

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None of the other lots present any age problems. I hope to complete describing the Callovian ammonites early this spring and at that time will sent you a summary of conclusions.
Report by: Ralph W. Imlay
Referred by: John K. Hartsock , Don J. Miller , Arthur Grantz
Age: Jurassic (Jurassic, no further definitive age is given in E&R report)
Formation: Naknek Formation (basal Naknek Formation)
Comment:Naknek formation
Occurrence(s)
No. Group Name Qty Notes
1 Ammonoids Cardioceras martini Reeside

Title: Geology of the Iniskin-Tuxedni Region, Alaska [last half of single issue publication] ,  1966
Report by: Robert L. Detterman , John K. Hartsock
Age: Callovian
Formation: Naknek Formation - lower sandstone member (lower sandstone member)
Comment:Geographic location: Chinitna Bay area
Map reference (pl. 3): 308
Stratigraphic position below top of formation (ft): 200-250
all above data from Table 12, p. 51
Occurrence(s)
No. Group Name Qty Notes
1 Ammonoids Cardioceras martini Reeside

Title: Late Jurassic Ammonites from Alaska ,  1981
Report by: Ralph W. Imlay
Age: Oxfordian (early Oxfordian)
Formation: Naknek Formation (unnamed lower sandstone member of Naknek Formation)
Comment:Shown as loc. 8 on Fig. 1; also shown on Figure 6 and Tables 2 and 5
Occurrence(s)
No. Group Name Qty Notes
1 Ammonoids Phylloceras iniskinense Imlay
2 Ammonoids Cardioceras (Scarburgiceras) martini Reeside