Sample Detail of
Sample: Sample No. 59ABg6 -- USGS No. Mesozoic loc. M530
Locality: Field No. 59ABg6
Description: Assigned USGS Loc. 530 in my report on shipment of A-59-4M dated 7/20/59. Sitka A-2 coordinates: 12.32, 8.53. (from Silberling E&R report of 7/21/59) [Silberling E&R report of 7/20/59 provides following description: Alaska, Admiralty Island. Near top of thin- to medium-bedded gray limestone that overlies thin-bedded fine-grained brownish gray crystalline limestone; total exposed thickness of limestone exceeds 200 feet. North shore of Herring Bay. Sitka A-2 quad; 12.32 in. perpendicular from west margin, perpendicular intersects west margin 8.53 in. up from SW corner. Coll.: H.C. Berg, 1959][Transmittal sheet of Lathram dated July 13, 1959, provides following description: Ammonites, cephalopods from near top of thin-to-medium-bedded gray ls. that overlies thin-bedded fine-grained brownish gray ls. Entire ls. unit not exposed but thickness exceeds 200 feet. Possibly Mesozoic-Triassic field stratigraphic assignment. Sitka A-2 coords: (12.32, 8.53)] [Transmittal sheet of Lathram dated 6/30/59 provides the following description: Ammonite and uncoiled cephalopod from near top of thin- to medium-bedded gray limestone that appears to underlie 59ABg5 and 5A. Entire limestone unit not exposed, but thickness exceeds 200 feet. Possibly Mesozoic/Triassic field stratigraphic assignment. Sitka A-2 coords: 12.32, 8.53]
Location: Alaska Quadrangle: Sitka A-2
Reference
Title: Report on Referred Fossils ,  1959 (07/21)
Report prepared by: N.J. Silberling, 7/21/59 (in collaboration with D.L. Jones)

For your information the following USGS locality numbers have been assigned to the Triassic collections retained from southeastern Alaska shipments A-57-14 and A-58-11 and reported on previously.

USGS Loc. No. - Field No. - Quad.
M509 - 58ALy36 - Sitka B-1
M510 - 58ALy204 - Sitka B-1
M511 - 58ALy221 - Sitka B-1
M512 - 58ALy136b - Sitka B-1
M513 - 58ALy290 - Sitka B-1
M514 - 58ALy330 - Sumdum B-6
M515 - 58ALy494 - Sumdum B-6
M516 - 57ADu62 - Sitka D-1
M517 - 57ADu66 - Sitka D-1
M518 - 57ADu74 - Sitka B-1
M519 - 57ADu75 - Sitka B-1
M520 - 57ADu77 - Sitka B-1
M521 - 57AL101 - Sitka B-1
M522 - 57AL57 - (locality data incomplete)
Report by: Norman J. Silberling , David L. Jones
Referred by: E. H. Lathram
Age: Carnian
Comment:Age: Late Triassic, Karnian. Additional specimens from this locality in shipment no. A-59-4M (my report to Lathram dated 7/20/59) provide a more refined age assignment of late Karnian.
Occurrence(s)
No. Group Name Qty Notes
1 Ammonoids Trachyceratid ammonite
2 Cephalopods Atractites sp.

Title: Report on Referred Fossils ,  1959 (07/13)
Report by: Norman J. Silberling
Referred by: E. H. Lathram
Age: Carnian (late Carnian)
Comment:The two ammonites listed first above are characteristic of the Tropites subbullatus zone of late Karnian (medial Late Triassic) age.

It is interesting to note that J.P. Smith (1927, Prof. Paper 141, p. 57) identified Juvavites (Anatomites externiplicatus from USGS Mesozoic locality 10180, the entry for which is: "Point between Chapin and Herring Bays, Admiralty Island," collected by Edwin Kirk, 1918.

These are the prettiest silicified ammonites I've seen, and although the age of the locality is tied down well enough on the basis of the present collection, more material would be gratefully accepted.

Occurrence(s)
No. Group Name Qty Notes
1 Ammonoids Juvavites (Anatomites) cf. J. (A.) externiplicatus Mojsisovics
2 Ammonoids Discophyllites ebneri Mojsisovics
3 Ammonoids Arcestes sp. indet.
4 Ammonoids Thisbites? sp.
5 Cephalopods Atractites sp.
6 Crinoids crinoid columnals

Title: letter ,  1959 (07/15)
To: Jack Pomeroy, c/o Alaskan Geology Branch, USGS, P.O. Box 2659, Juneau, Alaska

July 15, 1959

From: E.H. Cobb, Alaskan Geology Branch, USGS, Meno Park, California

Fossils; 59ABg6, 59APy244, 59APy301

Norm Silberling looked at your fossils and came up with the following preliminary guesses:

59ABg6 - Mesozoic; could be anywhere in the column, but looks like Cretaceous. Norm will workem over and give a formal report soon.

59 APy244 and 59APy301 - Probably Tertiary. Will be sent to the paleobotanist at CAl.

Ernie is still pretty well laid up, but seemed fairly comforatable last weekend. He would like to get back to Alaska about August first, but is far from hopeful.

E.H. Cobb
Geologist in Charge
Technical Data Section
Report by: E. H. Cobb
Referred by: J. S. Pomeroy
Age: Mesozoic
Comment:Mesozoic; could be anywhere in the column, but looks like Cretaceous. Norm [Silberling] will work them over and give us a formal report soon.