Sample Detail of
Sample: Sample No. 49AMr39 -- USGS No. Mesozoic loc. 21769
Locality: Field No. 49AMr39
Description: Tuxedni formation, Cynthia Falls member. Basal part of top of middle siltstone member, on southwest bank of Fitz Creek, 0.2 miles below the I.B.A. well; 1.94 miles S. 64o E. of Tonnie Peak, Iniskin Peninsula. (description from Imlay E&R report of 1/16/50)[Grantz transmittal sheet of Nov. 23, 1949 provides following description: "Siltstone outcrop on SW bank of Fitz Creek 0.2 mile below I.B.A. well; 1.94 miles S. 64o E. of Tonnie Peak. Field relations indicate basal Cynthia Falls or top of middle siltstone member of the Tuxedni formation."][Detterman and Hartsock, 1966, p. 32 (faunal list), loc. 89 on Pl. 3][Shown as locality 89 on Pl. 3 of Detterman and Hartsock, 1966]
Location: Alaska Quadrangle: Iliamna D-1
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: Cynthia Falls Sandstone (Cynthia Falls member of the Tuxedni formation)
Comment:Tuxedni formation
Occurrence(s)
No. Group Name Qty Notes
1 Ammonoids Chondroceras (Defonticeras) sp.
2 Ammonoids Phylloceras sp.

Title: Geology of the Iniskin-Tuxedni Region, Alaska ,  1966
Report by: Robert L. Detterman , John K. Hartsock
Age: Bajocian (middle Bajocian)
Formation: Fitz Creek Siltstone
Comment:Geographic location: Fitz Creek area
Map reference (pl. 3): 89
Stratigraphic position below top of formation (ft): 500-600
all above data from Table 6, p. 32
Occurrence(s)
No. Group Name Qty Notes
1 Ammonoids Phylloceras sp.
2 Ammonoids Chondroceras defontii (McLearn)