Sample Detail of
Sample: Sample No. 7-11-84B -- USGS No. 29614-PC
Locality: Field No. 7-11-84B
Description: From same locality as 7-11-84A but on opposite side of saddle and further from granite. Medium- to coarse-grained, crinoidal packstone with scattered dark-gray chert, at 4100 feet elevation; probably Kogruk Formation.
Location: Alaska Quadrangle: Ambler River B-1
Lat.: 67o25.7 ' Long.: 156o15.4 '
Reference
Title: Report on Referred Fossils ,  1985 (03/18)
REFERENCE CITED
Lane, H. R., Sandberg, C.A., and Ziegler, Willi, 1980, Taxonomy and phylogeny of some Lower Carboniferous conodonts and preliminary standard post-SIPHONODELLA zonation: Geologica et Palaeontologica, v. 14, p. 117-164.
Report by: Anita G. Harris , R. T. Lierman , Katharine S. Schindler
Referred by: William W. Patton , Jr. , Irv L. Tailleur
Age: Famennian-Osagean
Formation: Kogruk Formation
CAI:Min: 5 - Max: 5.5 (CAI=5-5.5 indicating host rock reached at least 300 to 350 deg. C. This is the regional thermal level in this area and provides no definitive information about the age of the Shishakshinovik pluton.)
Comment:8.51 kg of rock was processed (0 g of +20 mesh and 2 kg of 20-200 mesh insoluble residue); sample only partly picked.

This is a rather shallow-water species association indicative of the very latest Famennian through early Osagean, but probably no younger than Kinderhookian.

Age: very latest Devonian-early Early Mississippian (very latest Famennian-early Osagean)
CAI=5-5.5 indicating host rock reached at least 300 to 350o C. This is the regional thermal level in this area and provides no definitive information about the age of the Shishakshinovik pluton.

Occurrence(s)
No. Group Name Qty Notes
1 Conodonts Bispathodus stabilis (Branson & Mehl) transitional to
2 Conodonts Aculeatus anteposicornis (Scott) 15 Pa, 4 Pb, 19 M, 6 Sb, & 7 Sc elements
3 Conodonts 2 Pa elements of Ozarkodina crassidentata (Branson and Mehl)
4 Conodonts 1 Sc element
5 Conodonts 72 indet. bar, blade, and platform fragments
6 Unknown Abundant phosphatized crinoid ossicles, ostracodes, gastropods and bryozoans