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Reference
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| Title: |
Report on Referred Fossils
,
1972
(11/02)
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This report covers collections from Ignek Creek and Demarcation Point quad. The most significant fossils are those of Hauterivian age - the first recorded from northern Alaska. Coll: R.L. Detterman, 1971. |
| Report by: |
David L. Jones
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| Referred by: |
Robert L. Detterman
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| | Age: | No Data |
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| Comment: | Age: unknown |
| Occurrence(s) |
| No. |
Group |
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Name |
Qty |
Notes |
| 1 |
Ammonoids |
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Aptychus? |
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| 2 |
Bivalves |
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tiny pectinid clams |
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| 3 |
Bivalves |
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other indeterminable small clams |
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| 4 |
Unknown |
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tubes of unknown origin |
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| Title: |
Report on Referred Fossils
,
1973
(04/10)
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| Report by: |
Harlan Bergquist
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| Referred by: |
Robert L. Detterman
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| | Age: | Neocomian (Early Cretaceous (Neocomian)) |
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| Comment: | Sample 71ADt288 unit 4 is from the same locality as the Dt288 sequence of samples collected from the type section of the Ignek Formation, i.e. north bank of Ignek Creek, 2.8 to 4.5 miles upstream from the Canning River (lat. 69 degrees, 36 min. N., long. 146 degrees, 07 min. to 146 degrees, 11 min. W.). The sample is from a silty pebble shale section cited as Lower Cretaceous. The washed residue consists of particles of silty gray shale with subangular to subrounded quartz grains, pyritized rods which may be tubular fillings, and scattered flakes of mica. The sample yielded an abundant foraminiferal fauna and because it is a good fauna for correlative purposes, I picked all the material. As a result the number of recovered specimens is greater than would be normal for routine E and R work. Except for specimens of CONORBOIDES HOFKERI Bartenstin, the fauna is dominated by arenaceous species. The very numerous tests of C. HOFKERI are well preserved, probably of their aragonitic composition, whereas specimens with calcitic tests are few and seem to be largely corroded. CONORBOIDES HOFKERI along with the very abundant tests of VERNEUILINOIDES SUBFILLIFORMIS Bartenstein and Brand are diagnositc of a Neocomian age for the fauna. V. SUBFILLIFORMIS is an elongate triserial subcylindrical form which is the same one I have referred to in some earlier E and Rs as the verneuiline form of GAUDRYINA TAILLEURI Tappan. Next in abundance in the assemblage are narrow, coarse grained tests of AMMOBACULITES which at present I can only list as AMMOBACULITES sp. aff A. ALASKENSIS Tappan as they seem to be the same as the species described from Jurassic beds of northern Alaska. Abundant specimens of two species of HAPLOPHRAGMOIDES are questionably referred to HAPLOPHRAGMOIDES INFLATIGRANDIS Chamney and H. GOODENOUGHENSIS Chamney, both described from Barremian beds of the Mackenzie Delta area of northwestern Canada. Coarse grained specimens of a large REOPHAX are common and for present I identify these as REOPHAX sp. cf. METENSIS Franke although R. METENSIS has a Jurassic range. Specimens of AMMODISCUS are common and these I list as AMMODISCUS sp. aff. A. ROTALARIUS Loeblich and Tappan as they seem most closely allied to the form found in the Albian beds of northern Alaska. Tests of PSEUDOBOLIVINA? sp. in the assemblage are the same as some found in the Kemik Creek section and other areas of possible Neocomian strata, and I now think they also are a good indicator of Neocomian beds. The entire assemblage is listed below in order of relative abundance. Very abundant (over 50 specimens)
VERNEUILINOIDES SUBFILLIFORMIS Bartenstein and Brand
CONORBOIDES HOFKERI Bartenstein
Abundant (25 to 50 specimens)
AMMOBACULITES sp. aff. A. ALASKENSIS Tappan
HAPLOPHRAGMOIDES INFLATIGRANDIS Chamney?
Common (12 to 25 specimens)
AMMODISCUS sp. aff. A. ROTALARIUS Loeblich and Tappan
REOPHAX sp. R. METENSIS Franke
HAPLOPHRAGMOIDES GOODENOUGHENSIS Chamney?
PSEUDOBOLIVINA? sp.
MILIAMMINA? sp. (flattened tests - somewhat similar to M. SUBELLIPTICA Mellon and Wall from Albian of Alberta)
Rare (5 to 11 specimens)
LAGENA HAUTERIVIANA Bartenstein and Brand subspecies HAUTERIVIANA B & B
GAVELINELLA? sp.
PSEUDOBOLIVINA? SP. (distorted specimens)
MARGINULINA sp. aff. M. PINGUICULA Tappan (resembles Upper Jurassic form)
Very rare (fewer than 5 specimens)
TROCHAMMINA sp.
SACCAMMINA sp.
GYROIDINOIDES? sp.
GLOMOSPIRELLA sp.
BATHYSIPHON SCINTILLATA Chamney? (resembles form described from Barremian)
MILIAMMINA? sp.
TROCHAMMINOIDES sp. (pyritic casts)
MARGINULINA sp.
SARACENARIA? sp.
PYRULINOIDES sp.
DENTALINA sp. (broken - only early chambers present)
2 ostracode specimens |
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