Sample: |
Sample No. 61ABa1394
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Locality: |
Field No. 61ABa1394
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Description: |
About 100 feet below the top of unit 5, 3.4 mi. N. 41o W. of IBC monument 105; Lat. 64o 57.3'N; Long. 141o 04.5'W.; coords. (21.8, 17.2). Collector: E.E. Brabb, 1961. |
Location: |
Alaska Quadrangle: Eagle D-1 Lat.: 64o57.3 ' Long.: 141o04.5 ' |
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Reference
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Title: |
Report on Referred Fossils
,
1962
(03/20)
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This report concerns collection 61ABa1394, about 100 feet below the top of unit 5, 3.4 mi. N. 41 deg. W. of IBC monument 105; Lat. 64 deg. 57.3'N; Long. 141 deg. 04.5'W.; coords. (21.8, 17.2). |
Report by: |
Jean M. Berdan
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Referred by: |
Earl E. Brabb
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| Age: | Emsian (Revised; Robert B. Blodgett, 12/09/2006 ) (original assignment: Late Silurian - Early Devonian) |
Formation: | McCann Hill Chert - limestone and shale member (Revised; Robert B. Blodgett, 08/28/2005 ) |
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Comment: | As mentioned in our conference of March 2, 1962, the fauna in this collection appear to be an Arctic assemblage about which very little is known. Consequently, the ostracodes are not too much help in dating these rocks. The following ostracode genera have been found in this collection: (see faunal list - comment by R.B. Blodgett) Five of the genera listed above, Saccharchites, Bairdiocypris, Tubulibairdia, Tricornina and Acanthoscapha, range from the Upper Silurian into the Middle Devonian, are are not much help for precise dating. Of the other four named genera, Beyrichia (Beyrichia) and Dibolbina have not been reported above the Upper Silurian, and Adelphobolbina and Hanaites have not been reported below the Middle Devonian. The form lists as "N. gen., n. sp." also occurs in rocks of undeterminated age, possibly Early Devonian, from Nevada. As indicated by the queries and other equivocations, several of the forms assigned to critical genera are not firmly identified. In some instance, for example, Dibolbina? and the gen. aff. Hanaites, this is because only one specimen was available for study, and that one not well preserved. The form listed as Adelphobolbina? was represented by several specimens, but is not precisely like typical Adelphobolbina; it appears to be intermediate between that genus and the Silurian genus Triemilomatella, but seems more like the former. Beyrichia (Beyrichia) arctigena was described by Martinsson in Geol. Survey of Canada Bull. 65, A Late Silurian fauna from the Sutherland River Formation, Devon Island, Canadian Arctic Archipelago, by Boucot and others, 1960. The species in this collection is similar to B. (B.) arctigena, but is considerably more papillose, and may not be conspecific. The other kinds of fossils represented in this collection are at least superficially similar to those described from the Sutherland River Formation. However, the age of the latter is by no means as certain as the title of the paper indicates, and in deciding on a Late Silurian age, considerable weight seems to have been given to the presence of Beyrichia (Beyrichia). Unfortunately there is no firm assurance that this subgenus could have ranged at least into the lower Lower Devonian (Helderbergian of the eastern United States, Gedinnian of Europe). Trying to evaluate all these bits and pieces of information, my best guess, and it is only a guess, is that the age of the collection is Late Silurian or early Early Devonian. I would not think it would be as young as Middle Devonian. |
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Title: |
Report on Referred Fossils
,
1962
(04/05)
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Report by: |
John W. Huddle
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Referred by: |
Earl E. Brabb
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| Age: | Emsian (Revised; Robert B. Blodgett, 12/09/2006 ) (original assignment: ) |
Formation: | McCann Hill Chert - limestone and shale member (Revised; Robert B. Blodgett, 08/28/2005 ) |
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Comment: | The slide submitted to me contains two specimens of a species of Spathognathodus. It is probably the species figured by Ziegler, 1960 as Spathognathodus cf. S. frankenwaldensis Bischoff and Sannemann from the Lower Devonian (Gedinnian) of the Rheinisches Schiefergebirge. It is similar but not identical to Spathognathodus canadensis Walliser which was described from the Sunderland River Formation, Devon Island, Canada and assigned a late Silurian age. As suggested by Ziegler a formation containing Spathoganthodus cf. frankenwaldensis is probably slightly younger than the Sunderland River Formation, and therefore Gedinnian or perhaps Siegenian in age. Age determinations based on two specimens of a single species are questionable, but a Lower Devonian age is suggested. References: Walliser, in Boucot and others, 1960, Geol. Survey of Canada, Bull. 65, 48 pp. Ziegler, W., 1960, Palaontologische Zeitschrift, vol. 34, no. 2, p. 169-201. |
Occurrence(s) |
No. |
Group |
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Name |
Qty |
Notes |
1 |
Conodonts |
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Spathognathodus sp. |
2 specimens |
probably the species figured by Ziegler, 1960 as Spathognathodus cf. S. frankenwaldensis Bischoff and Sannemann |
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Title: |
Report on Referred Fossils
,
1961
(11/06)
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This report concerns 10 collections of trilobites and other fossils, mostly from Cambrian rocks. The 9 Cambrian collections will be dealt with in groups related to the collection localities in the vicinity of Chief Mtn. and Crow triangulation station. The one Devonian collection is only briefly mentioned as it contains an ostracod fauna that should be more definitive than the trilobites and has been turned over to Jean Berdan for further comment. |
Report by: |
A. R. Palmer
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Referred by: |
Earl E. Brabb
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| Age: | Emsian (Revised; Robert B. Blodgett, 12/09/2006 ) (original assignment: Early Devonian (upper part) - Middle Devonian) |
Formation: | McCann Hill Chert - limestone and shale member (Revised; Robert B. Blodgett, 08/28/2005 ) |
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Comment: | This collection includes a proetid trilobite referable to Dechenella which is a genus that ranges from the upper part of the lower Devonian to the Upper Devonian; and an odontopleurid seemingly referable to Ceratocephala, a genus ranging from the Middle Ordovician to the Middle Devonian. Assuming no extensions of known ranges, this indicates that the age of the collection is no younger than Middle Devonian and no older the upper part of the lower Devonian. |
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Title: |
Report on Referred Fossils
,
1962
(03/22)
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This report concerns collection 61ABa1394, about which reports on the trilobites (Palmer, 11/6/61), ostracodes (Berdan, 3/20/62), and conodonts (Huddle, 4/5/62) have already been made. In addition to these three groups of fossils, there are also brachiopods, molluscs and echinoderms. The entire collection has been examined with an end in view of sharpening the age assignment. Unfortunately, the brachiopod faunule is one that characterizes both latest Silurian and earliest Devonian assemblages. These shells were examined also by A.J. Boucot who reports that they appear like faunas that he has examined from high in the Cape Phillips Formation of the Canadian Arctic. The Cape Phillips is Early Devonian in uppermost part. Huddle's suggestion that the collection represents Gedinnian or Siegenian equivalents is probably as close as we can get with the present information. The Devonian aspect of the trilobites would be more reasonably explained by such an assignment. In conclusion, it seems best at present to consider the assemblage as Early Devonian (pre-Oriskany) in age. It is understood that a latest Silurian age is not ruled out completely, however. |
Report by: |
J. Thomas Dutro
, Jr.
,
Arthur J. Boucot
,
Jean M. Berdan
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Referred by: |
Earl E. Brabb
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| Age: | Emsian (Revised; Robert B. Blodgett, 12/09/2006 ) (original assignment: Early Devonian (pre-Oriskany)) |
Formation: | McCann Hill Chert - limestone and shale member (Revised; Robert B. Blodgett, 08/28/2005 ) |
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Comment: | Reference: Boucot, A.J. et al, 1960, A Late Silurian fauna from the Sutherland River Formation, Devon Island, Canadian Arctic Archipelago: Geol. Survey Canada Bull. 65, 55 pp., 10 pls. |
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Title: |
Report on Referred Fossils
,
1963
(10/03)
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Report by: |
John W. Huddle
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Referred by: |
Earl E. Brabb
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| Age: | Emsian (Revised; Robert B. Blodgett, 12/09/2006 ) (original assignment: Early Devonian (probably Emsian) - early Middle Devonian) |
Formation: | McCann Hill Chert - limestone and shale member (Revised; Robert B. Blodgett, 08/28/2005 ) |
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Comment: | Formic acid residues of your second collection prepared by Jean Berdan have yielded additional conodonts. The following species have been found: (see faunal list) Acodus, Distacodus, Panderodus and Scandodus are single cusp conodonts with long ranges. Belodella devonica and B. triangularis have been reported from the Devonian clay above the Cedar Valley Limestone in Minnesota, and the Lower Devonian of Germany. Euprioniodina and Hindeodella are long ranging forms. Icriodus beckmanni Ziegler has been reported from Lower Devonian of Germany and the Middle Devonian of U.S. Icriodus woschmidti has only been reported from the Gedinnian (L. Dev.) of Germany. Ozarkodina denckmanni ranges from upper Ludlow to Emsian in Germany. Pelekysgnathus has been found only in Middle and Upper Devonian rocks of U.S. Polygnathus linguliformis is a common Middle Devonian form but ranges from Emsian to Upper Devonian. Spathognathodus n. sp. figured by not described by Walliser 1963 (compared with S. frankenwaldensis Walliser in my previous report), ranges from middle Ludlow to Emsian in Germany. It may be the same as Spathognathodus incetis (Stauffer) from the "Devonian clay of Minnesota" probably derived from the Cedar Rapids Limestone of Middle Devonian age. Most of the conodont information indicates a Lower Devonian age, probably Emsian. However that date depends heavily on German conodont ranges and does not eliminate the possiblity of an early Middle Devonian age which the other paleontologic evidence seems to indicate. |
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