Reference Detail of

Report on Referred Fossils
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Stratigraphic range: Permian
Kinds of fossils: Invertebrates
Quadrangle or area: Demarcation Pt. and Table Mtn. quads., Alaska
Shipment No.: A-71-15
Referred by: Detterman, Robert L.
Report prepared by: Dutro, J. Thomas, Jr.
Date: 02/17/1972

Summary

All 18 collections reported on here are of Permian age and supplement the reports of last year (A-70-10, A-70-20, A-70-22) on the faunas of the Sadlerochit Formation.

With the publication of the Bamber and Waterhouse paper on the Carboniferous and Permian stratigraphy in northern Yukon (1971), we now have a chance for comparison with those faunas. My earlier suggestion, that the more southern belts of Sadlerochit might have older faunas in the lower part of the formation, seems to be born out by this year’s analysis.

Of special interest in this regard are the collections from stations 303, 318 and 348. As station 303, the collection from 65 ft. above the base may be correlated with Waterhouse Zone Ea which he calls lower Permian (Sakmarian). The collections from 265-350 ft. are possibly some part of Zone F (Artinskian to Ufimian). At station 318, collections from units F, G, and H may also be of Waterhouse Zone F age. No Zone G was definitely recognized in these two sections. At station 348, unit 4 (350-375 ft.) represents the characteristic Zone G that is found in the lower part of the Echooka along the northern belt and as far south as the section at the forks of the Aichillik. As noted last year, this fauna is at 175-202 ft. at station 202.

Other collections that are Zone G (previously called the “lower Echooka fauna”) are: 284 (unit 2), 327 and, possibly, 283 (unit 3+70’), 290 (units 2, 3), and 296 (unit 1).

Verification of these zonal correlations awaits detailed taxonomic restudy of all the available collections, but the suggestion that earlier assemblages are present at the latitude of the upper Kongakut is worth consideration in any regional stratigraphic reconstruction. One implication of this analysis is that the lower, fine-grained part of the sequence along Joe Creek and nearby areas may be a lateral equivalent of part of the Siksikpuk Formation. It is of interest to note that a similar occurrence of zones is recorded by Bamber and Waterhouse from the northern Richardson Mts. Sections (Fig. 10 in their paper).

In this report, the megousid species are listed as Kuvelousia, as is probable from Waterhouse’s new taxonomy, and Yakovlevia is used rather than Muirwoodia. The F and G zones of Waterhouse collectively compose what I have earlier called the “Arctic Permian faunas.”

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71ADt283 (unit 3+ 70 ft.) (23452-PC) , Demarcation Point , Ridge west of Aichilik River, 0.1 mile south of VABM Atte; Lat. 69 deg. 29'30" N., long. 143 deg. 07' W.; massive quartzite 175 feet below base of Triassic.
Chonetina?
Liosotella?
productoid, indet.
stenoscismid, indet.
Spiriferella sp.
71ADt 284 (unit 2) (23453-PC) , Demarcation Point , Ridge west of Egaksrak River, 3.2 miles N. 85 deg. E. of VABM Hule; lat. 69 deg. 32'30" N., long. 142 deg. 46' W. Thin bedded, limonitic quartzite; about 100-150 feet above base of formation.
?Kuvelousia sphiva
71ADt290 (unit 2) (23454-PC) , Demarcation Point , West fork Aichilik River, 2.8 miles S. 60 deg. W. of junction with main Aichilik, lat. 69 deg. 22'15" N., long. 143 deg. 09'30" W.; thin bedded, clacareous, limonitic quartzite, 310 to 330 feet below Triassic.
Spiriferella? sp.
71ADt 290 (unit 3) (23455-PC) , Demarcation Point , Same locality as unit 2, medium bedded calcareous quartzite with thin limestone interbeds 180-210 feet below Triassic.
Spiriferella sp.
horn coral, undet.
71ADt296 (unit 1) (23456-PC) , Demarcation Point , Ridge east of Jago River, 6.2 miles N. 63 deg. E. of Marie Mountain, lat. 69 deg. 27' N., long 143 deg. 28'30" W.; massive fine grained, conglomeratic quartzite 35 to 40 feet above base and about 450 feet below Triassic.
stenoporoid bryozoans, indet.
Chonetina? sp.
Anidanthus? sp.
productoid fragments, indet.
71ADt303 (+65 ft.) (23457-PC) , Demarcation Point , Mountain west of Kongakut River, 7.2 miles N. 5 deg. E. of point where Kongakut crosses into Table Mt. Quad., lat. 69 deg. 06'20" N., long. 142 deg. 08' W.; brownish calcareous mudstone 65' above base of formation and about 310 feet below Triassic.
Chonetina? sp.
Attenuatella? sp.
fragmentary snail, indet.
71ADt303 (+ 265-275 ft.) (23458-PC) , Demarcation Point , Same locality as above [71ADt 303 (+65 ft.); thin bedded limy sands 265 feet above base and about 110 feet below Triassic.
Anidanthus? sp.
Waagenoconcha? sp.
spiriferoid, possibly Septospirifer
71ADt303 (+ 350 ft.) (23459-PC) , Demarcation Point , Same locality as above [71ADt303 (+65 ft.)]; massive quartzite, about 25 feet below Triassic.
large productoid, indet.
rhynchonelloid, indet.
Septospirifer? sp.
small straparollid snails, indet.
71ADt 318A (23460-PC) , Table Mtn , Mountain north of Joe Creek, Table Mt. Quad., 4.8 miles west of VABM Raeburn, lat. 68 deg. 59'30" N., long. 141 deg. 26' W.; brown silty calcilutite, 85' to 100 feet above base.
Martinia sp.
long, sand-filled burrows
71ADt 318D (23461-PC) , Table Mtn , Same locality as 318A above. Massive silicified limestone 190 to 200 feet above base.
Septospirifer? sp.
productoids, small and indet.
mollusc fragment, indet.
71ADt 318F (23462-PC) , Table Mtn , Same locality as 318A above. Thin quartzitic silstone 220-240 feet above base.
Waagenoconcha sp.
Rhynchopora sp.
Cleiothyridina sp. (large)
Tomiopsis? sp.
71ADt 318G (23463-PC) , Table Mtn , Same locality as 318A. Interbedded thin limestone and quartzite 330-360 feet above base.
stenoporoid bryozoans, indet.
Derbyia sp.
Yakovlevia sp.
Horridonia sp.
Kochiproductus sp.
Spiriferella sp.
brachiopod fragments, indet.
71ADt 318G-H (23464-PC) , Table Mtn , Float? Same locality as 318A.
Kochiproductus sp.
71ADt 318H (23465-PC) , Table Mtn , Same locality as 318A. Thin bedded limestone 360-370 feet above base.
Derbyia sp.
Yakovlevia sp.
productoids, indet.
Spiriferella sp.
Cleiothyridina? sp.
pelecypods, indet.
71ADt 323 (23466-PC) , Table Mtn , Mountain north of Joe Creek, 2.8 miles S. 80 deg. W. of VABM Raeburn, lat. 68 deg. 59' N., long. 141 deg. 21' W.; thin bedded calcilutite rubble about 50-100 feet above base.
large U-shaped burrows, indet.
large productoid, indet.
Spiriferella sp.
71ADt327 (23467-PC) , Demarcation Point , Mountain top east of Egaksrak River, Demarcation Pt. Quad., 3.2 miles N. 15 deg. E. of VABM Nob, lat. 69 deg. 35' N., long. 142 deg. 29' W., interbedded quartzite and limestone 10 to 60 feet above base.
Kuvelousia sphiva Waterhouse
71ADt 348 (unit 4) (23468-PC) , Table Mtn , Mountain south of Kongakut River - Table Mt. Quad., 20 miles S. 65 deg. W. of point where Kongakut enters Table Mt. Quad., lat. 68 deg. 56'30" N., long. 142 deg. 55' W.; thin bedded limestone, 350 to 375 feet above base.
fenestrate bryozoan, indet.
Horridonia sp.
Kuvelousia sphiva Waterhouse
productoid, indet.
Spiriferella sp.
Punctospirifer? sp.
pectenoid pelecypod, indet.
trilobite pydigium, indet.
71ADt 348 (unit 5) (23469-PC) , Table Mtn , Same locality as unit 4 [71ADt 348]; thin calcareous siltstone, 250 to 350 feet above base.
Timaniella? sp.
Neophricadothyris? sp.