| Sample: |
Sample No. 69ADt40 -- USGS No. Mesozoic loc. 29856
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| Locality: |
Field No. 69ADt40
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| Description: |
Ignek Mesa - Ignek Valley, 6.8 miles S. 75o E of Katakturuk Canyon. Concretions in black silty clay shale about 80 feet below basal Ignek Sandstone.(desc. from E&R report; USGS Mesozoic loc. 29856. Ignek Mesa in Ignek Valley, 6.8 miles S. 75° E. of Katakturuk Canyon, lat 69°33'30" N., long 145°20' W., northeast Alaska. Cardioceras (Scarburgiceras). (description from Imlay and Detterman, 1973, p. 25); R. L. Detterman. 1969. Ignek Mesa in Ignek Valley. 11 km S. 75° E. of Katakturuk Canyon, lat 69°33'30" N., long 145°20' W., east-central part of sec. 6, T. 2 N.. R. 28 E., Mt. Michelson Quadrangle. Fossils from concentrations in black silty clay shale of Kingak Shale about 24 m below top. Earlv Oxfordian. (description from Imlay, 1981, USGS PP 1190, p. 23); [USGS Mes. Cat.: 29856 (69 ADt40) Kingak Fm. Oxfordian.Ignek Mesa - Ignek Valley, 6.8 miles S 75° E of Katakturuk Canyon. Lat. 69°33'30" N., Long. 145°20' W., concretions in black silty clay sh about 80 ft. below basal Ignek SS, Mt. Michelson quad., NE Alaska. Coll. by R.L. Detterman, 1969] |
| Location: |
Alaska Quadrangle: Mt Michelson C-3
Lat.: 69o33'30 " Long.: 145o20' " |
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Reference
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| Title: |
Report on Referred Fossils
,
1969
(10/08)
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The fossils from the Kingak Formation exposed in the northeastern part of the Brooks Range are of Early Jurassic to early Oxfordian ages. |
| Report by: |
Ralph W. Imlay
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| Referred by: |
Robert L. Detterman
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| | Age: | Oxfordian |
| Formation: | Kingak Shale |
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| Comment: | In Europe the genus Cardioceras occurs in the lower part of the Oxfordian stage. The subgenus Scarburgiceras is characteristic of the Quenstedtoceras mariae zone but ranges into the lower part of the overlying zone of Cardioceras cordatum. Scarburgiceras has been found previously on Fire Creek at Lat. 69°32'N, Long. 145°09'W (Mes. loc. 29137). |
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| Title: |
Jurassic Paleobiogeography of Alaska
,
1973
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ABSTRACT: Jurassic marginal seas occupied considerable areas in southern and northern Alaska and in the western part of the Kuskokwim region of southwestern Alaska. They appear to have been absent during late Callovian time, much restricted during Hettangian, Bathonian, early Oxfordian and late Tithonian time, and most extensive during Sinemurian, Bajocian, and late Oxfordian to middle Tithonian time. A large area in central Alaska was probably never covered. A southwestern prolongation of that area from the Talkeetna Mountains westward to the western end of the Alaska Penin- sula was the site of granitic intrusions during late Early Jurassic time and of extensive erosion during Middle and Late Jurassic time. Variations in the rate of uplift of the area of these granitic intrusive rocks may explain why marine transgressions and regressions were at different times in southern than in northern Alaska during the Bajocian and Bathonian. Connection of the northern and southern marginal seas occurred through Yukon Territory and eastern- most Alaska. The Jurassic ammonite succession in Alaska is similar to that in central and northern Europe and northern Asia. In Lower Jurassic beds, it is essentially identical. In Bajocian and in Oxfordian to lower Kimmeridgian beds, the ammonite succession in Alaska differs from that in the other areas mainly by the presence of some genera found only in areas bordering the Pacific Ocean and by the absence of a few genera common in central and northern Europe. In con- trast, the Bathonian rocks of Alaska contain ammonites, such as Arcticoceras, Arctocephalites, and Cranocephalites, that are widespread in the Arctic region but are unknown in central Europe. Comparisons with the Tithonian of Europe are not possible because ammonites of that age, other than Lytoceras and Phylloceras, are not yet known from Alaska. The Alaskan Jurassic ammonites of late Pliensbachian Age and of Bathonian to early Kimmeridgian Age belong mostly to the Boreal realm and have very little in common with Tethyan realm ammonites such as those found in areas bordering the Mediterranean Sea. |
| Report by: |
Ralph W. Imlay
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Robert L. Detterman
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| | Age: | Oxfordian (early Oxfordian) |
| Formation: | Kingak Shale |
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| Comment: | Generalized locality shown shown as locality 1 in figure 6 |
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