Sample Detail of
Sample: Sample No. 50AGr31 -- USGS No. Mesozoic loc. 22598
Locality: Field No. 50AGr31
Description: George Gryc, R. W Imlay, and A. N. Kover, 1950. West bank of Canning River at same place as USGS Mesozoic loc. 21028. Kingak Shale about 61 m below top. Late Oxfordian to early Kimmeridgian. (description from Imlay, 1981, USGS PP 1190, p. 23); [USGS Mes. Cat.: (orig. no. 50AGr31. Upper Jurassic - Kingak. Northern Alaska, Canning River District, SE1/4, NE1/4, Quad. 6F. Lat: 69°30'45" W., Long: 145°18'45" N., 200 to 500 ft. below base Ignek (Cret.) ss. Same locality as 47AGr239. ((USGS No. 21028) on Canning River. Slumped shale, poorly exposed. Coll: Gryc, Imlay, Kover. N. 8 Ref: Gryc 1950, p. 8. July 17, 1950.]; George Gryc, R. W. Imlay, Allan Kover, 1950. Canning River at same locality as Mes. loc. 21028. From 200 to 500 feet below top of Kingak shale. Upper Jurassic, upper Oxfordian or lower Kimmeridgian. (description from Imlay, 1955, USGS PP 274-D, p. 80)
Location: Alaska Quadrangle: Mt Michelson C-4
Lat.: 69o30'45 " Long.: 146o18'45 "
Reference
Title: Late Jurassic Ammonites from Alaska ,  1981
Report by: Ralph W. Imlay
Age: Oxfordian-Kimmeridgian (late Oxfordian - early Kimmeridgian)
Formation: Kingak Shale (Kingak Shale (upper part, near top))
Comment:Shown as locality 1 on Fig. 1; also shown on Fig. 2 and Table 4

"Other specimens of Amoeboceras and Buchia concentrica were collected from the upper 50 feet (15 m) of the Kingak Shale exposed on the west side of the Canning River about 9 miles (14.4 km) north of Cache Creek and 2.5 miles (4 km) south of Black Island at USGS Mesozoic Iocs. 24013, 24014, 21028, 22598, and 29882." (from Imlay, 1981, USGS PP. 1190, p. 15

"Occurrences.—Kingak Shale in northern Alaska at USGS Mesozoic Iocs. 21028, 22598, and 29135 in association with Buchia concentrica (Sowerby)." (from Imlay, 1981, USGS PP 1190, p. 36.

Occurrence(s)
No. Group Name Qty Notes
1 Bivalves Buchia concentrica (Sowerby)
2 Ammonoids Amoeboceras (Prionodoceras?) cf. A. (P.?) prorsum Spath

Title: Characteristic Jurassic mollusks from northern Alaska ,  1955
The fossils from the Jurassic strata of northern Alaska prove that the Lower, Middle, and Upper Jurassic series are represented but suggest that certain stages or parts of stages are not represented. There is no faunal evidence for the presence of the middle and upper parts of the Bajocian, the entire Bathonian, the upper part of the Callovian, the lower Oxfordian, or the upper Portlandian. Field evidence shows that a disconformity occurs at the stratigraphic position of the upper Portlandian. Both field and subsurface data suggest an unconformity immediately preceding the upper Oxfordian. The absence of faunal evidence for certain stages, or parts of stages,may be related to the fact that elsewhere in Alaska and in the western interior of North America major retreats of Jurassic seas occured during Bathonian, late Callovian, and Portlandian times. Although the Jurassic strata in northern Alaska are generally impoverished faunally, nevertheless, in many places interpretations of the stratigraphy or the structure are based on the fossils present, or the fossils are used as supplementary evidence. Wherever the faunal succession can be determined in northern Alaska, it agrees essentially with that elsewhere in the Boreal region and in other parts of North America and in northwest Europe. Faunal and lithologic relationships suggest that the eastward-trending Jurassic seaway of northern Alaska had rather uniform and moderately steep slopes along its northern and southern margins and that more than half of its sea bottom was stagnant and at least as deep as the lower part of the neritic zone. The existence of moderately deep water may explain the presence of the ammonites Phylloceras, Lytoceras, and Reineckeia, which are missing in the shallow-water Jurassic strata in the interior of North America, in east Greenland, and in the Barents Sea area. The scantiness of the fauna over much of the seaway is problably related to unfavorable bottom conditions and to an inadequate supply of certain materials such as phosphate. Fairly warm waters during Early Jurassic and early Middle Jurassic (Bajocian) time is indicated by the presence of ammonites that had a nearly worldwide distribution. Somewhat cooler waters and the presence of climatic zones during the Late Jurassic in Alaska, as in other parts of the Boreal region, is indicated by the presence of molluscan genera quite distinct from those in the Late Jurassic of the Mediterranean region.
Report by: Ralph W. Imlay
Age: Oxfordian-Kimmeridgian (late Oxfordian - early Kimmeridgian)
Formation: Kingak Shale
Comment:Shown as loc. 27 on Fig. 20 and also on Table 2

A few specimens associated with A. spitiensis Holdhaus and the ammonite Amoeboceras (Prionodoceras) at Mes. locs. 21028 and 22598 are probably of late Oxfordian age, as Prionodoceras is characteristic of the late Oxfordian and is rare in the early Kimmeridgian. (from Imlay, 1955, p. 83)

In northern Alaska A. spitiensis is associated at Mes. Iocs. 24014 and 22598 with the ammonite Amoeboceras (Prinodoceras?}, whose presence is excellent evidence that A. spitiensis existed in the late Oxfordian or early Kimmeridgian. (from Imlay, 1955, p. 84)

Occurrence(s)
No. Group Name Qty Notes
1 Bivalves Lima sp.
2 Bivalves Aucella concentrica (Sowerby) The genus Aucella is now placed in the genus Buchia [additional note: specimen from this locality illustrated on Pl. 9, fig. 15]
3 Bivalves Aucella spitiensis Holdhaus The genus Aucella is now placed in the genus Buchia (Additional note: specimens from this locality illustrated on Pl. 9, figs. 1,2,3, 4, 7, 8, 9)
4 Bivalves Tancredia sp.
5 Ammonoids Amoeboceras (Prionodoceras?) spp. juv. specimens from this locality illustrated on Pl. 12, figs. 2, 6