Reference Detail of

Report on Referred Fossils
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Stratigraphic range: Devonian - Mississippian
Kinds of fossils: Plant
Quadrangle or area: Arctic, Table Mountain, Mt. Michelson, Chandler Lake, Wiseman
Shipment No.: A-78-23
Referred by: Brosge, William P.
Report prepared by: Mamay, Sergius H.
Date: 03/21/1979

Fourteen collections consisting largely of black shale samples, most of which contain poorly preserved plant fossil material, make up the suite of material sent to me for paleobotanical appraisal.

Inasmuch as your transmittal sheet indicated that a large proportion of this suite could or should be Devonian, I considered it only appropriate that I solicit the aid of our local authority on Devonian plants for consultation, confirmation or correction of my opinions. I therefore asked Fran Hueber (USNM) for some assistance and he gave generously of his time and expertise to go over the material with me. The following report, then, incorporates Fran’s opinions and mine; in general we were in total accord (except in a couple of cases where I did not know and he did).

There are a couple of discrepancies between your locality descriptions and the collections I received. You list a 78ABe 46A, but there is no such sample in this lot; 78ABe 65B is missing, but I do have a 65C. Both of these missing collections are from the Arctic quad. (ARR 15B, from the original PSEUDOBORNIA locality, is also missing, it is mentioned in remark No. 3 on your transmittal sheet.).

You inquired specifically about Devonian—Mississippian differentiation in the Arctic quad. On the basis of the two Kanayut (33E; 33G) and one Kekiktuk collections available, it appears that those two formations do, in fact, represent the Devonian and Mississippian, respectively, in the Arctic quad, and determinable plant fossils can be used to identify those formations. The Kanayut plants indicate Devonian age, and the Kekiktuk material is Mississippian. It would be nice to see more varied and better-preserved specimens, of course, for further corroboration of this opinion (this is not intended to disparage your collecting efforts; I understand from Tom Dutro that a lot of energy went into gathering what you did, and I believe it!).

The samples are being retained for the P&S reference set.


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Brief statement of problem and remarks (from collector):
1. The Kekitktuk Conglomerate is supposed to be Mississippian and the Kanayut Conglomerate upper Devonian. It is possible that both are Devonian in the Arctic quad? Can we use the plants to identify the formation?

2. Wacke in big Klippen(?) near Arctic Village looks like the fossiliferous Devonian wacke but contains only plants (78ARR3B). Could it be Mesozoic?

3. 78ARR15B is a new collection from the original Psuedobornia locality 60ARR635.

4. In some places (78ARR48A) it is hard to distinguish Kayak Shale (Miss) from Stuver Member of Kanayut (Dev).
User Note module to be added
78ABe-33E , Arctic , Devonian. Arctic Quad., 68 deg. 25 min. 30 sec. N., 145 deg. 02 min. 35 sec. W. Base of Kanayut Conglomerate; underlain by Hunt Fork shale.
Hostimella sp.
Psilophyton sp.
78ABe-33G , Arctic , Same locality as 33E above.
Hostimella sp.
Drepanophycus? sp.
78ABe-42A , Table Mtn , Upper Devonian or Lower Mississippian. Table Mtn. Quad., 68 deg. 34 min. 40 sec. N., 142 deg. 49 min. 00 sec. W. Kanayut(?) or Kekiktuk(?) Conglomerate (base not exposed; plant occurrence resembles Kekiktuk); cycles about 5 ft. thick of chert-quartz pebble (to 2 inches) conglomerate and coarse quartzite.
Archaeopteris? sp. or ....
.... Rhacopteris? sp. or ....
.... Sphenopteridium? sp.
78ABe-42B , Table Mtn , Questionable age. Same locality as 42A above.
thick stem impression, likely a lycopod
78ABe-43A , Table Mtn , Lower Mississippian. Table Mtn. Quad., 68 deg. 53 min. 40 sec. N., 142 deg. 13 min. 40 sec. W. Kanayut(?) or Kekiktuk(?) Conglomerate (base not exposed); dark brown, thin-bedded fine-grained, ripple-marked micaceous sandstone and black silt shale. Few hundred feet below base of Kayak Shale and about 1000-1500 ft. above massive conglomerate.
unbranched plant axes
Lepidodendropsis scobiniformis (Meek) Read
Zoophycus sp. ...
.... or Taonurus
78ABe-46F , Arctic , Probably Upper Devonian. Arctic Quad., 68 deg. 40 min. 40 sec. N., 145 deg. 52 min. 56 sec. W., Kanayut Conglomerate (base not exposed); Upper member, about 600 ft. thick, member overlain by Kayak Shale and underlain by conglomeratic middle member and incomplete lower member.
poorly preserved plant material
78ABe-47B , Arctic , Lower Mississippian. Arctic Quad., 68 deg. 58 min. 00 sec. N., 145 deg. 34 min. 59 sec. W., Kekiktuk Conglomerate.
poorly preserved plant materail
Adiantites sp.
78ABe-58A , Mt Michelson , Age questionable. Kekiktuk Conglomerate; Mt. Michelson Quad., 69 deg. 01 min. 35 sec. N., 145 deg. 04 min. 50 sec. W
unbranched, naked plant axes
78ABe-65C , Arctic , Age indeterminate. Kayak or Devonian(?) Shale, Arctic Quad., 68 deg. 52 min. 10 sec. N., 144 deg. 32 min. 35 sec. W.
78ABe-108B , Chandler Lake , Probably Mississippian. Kanayut Conglomerate. Chandler Lake quad. 68 deg. 12 min. 25 sec. N., 151 deg. 12 min. 30 sec. W. Stuver Member, Shaley zone 100-150 ft. thick near base of member. Composed of gray green siltstone and thin-bedded sandstone with thin zones of white conglomerate and four zones of carbonaceous siltstone and sandstone.
Lepidodendropsis? sp.
78ABe-212 , Wiseman , Age uncertain. Kanayut Conglomerate. Wiseman Quad., 67 deg. 56 min. 15 sec. N., 151 deg. 01 min. 30 sec. W. Stuver Member; upper 200 ft. composed of cycles 2-5 ft. thick of massive quartzite, x-bed quartzite and dark shaley s.s. and black shale.
Plant fragments
78ARr-3B , Arctic , Age indeterminate. Arctic Quad., 68 deg. 20 min. 18 sec. N., 144 deg. 47 min. 30 sec. W. Gray green quartz wacke and dark gray shale.
Plant fragmentary material
78ARr-48A , Chandler Lake , Mississippian. Chandler Lake Quad., 68 deg. 10 min. 00 sec. N., 151 deg. 46 min. 20 sec. W. Kayak Shale(?) or Stuver Member(?) of Kanayut Conglomerate.
naked, unbranched stems
78CHA-15 , Chandler Lake , Probably Mississippian. Chandler Lake Quad., 68 deg. 15 min. 50 sec. N., 152 deg. 45 min. 30 sec. W. Kanayut Conglomerate, Stuver Member. From middle of 6 ft. unit of carbonaceous shale directly overlain by basal wormy s.s. of the Kayak Shale and underlain by 16 ft. of cover followed by medium-grained x-bed s.s.
fragmentary stem casts