Reference Detail of

Report on Referred Fossils
Edit Reference Add/Edit Sample Sample List Show Map
Stratigraphic range: Lower Cretaceous and Upper Triassic
Kinds of fossils: Mollusks
Quadrangle or area: Goodnews Bay, Taylor Mountains, Bethel
Shipment No.: AF-50-34
Referred by: Hoare, Joseph M.
Report prepared by: Reeside, John B., Jr.
Date: 12/19/1950

Three faunas are present in these collections. The youngest is marked by Aucella crassicollis Keyserling and is of Lower Cretaceous age. The next older is an Upper Triassic assemblage with Pseudomonotis subcircularis Gabb, of Noric age. The third is also Upper Triassic and is marked by Halobia, of Karnic age. One lot contains reworked Later Paleozoic bryozoans.

User Note module to be added
50AHr263 (Mesozoic loc. 23165) , Taylor Mts , 16 1/3 miles S. 10 1/2 deg. E. of Gemuk Mountain; 10 1/2 miles S. 46 1/2 deg. E. of outlet of Aniak Lake; 1 1/2 miles S. 35 1/2 miles W. of outlet of lake between Nishlik and Upnuk Lakes. From the headwall of the cirque which is at the head of the easternmost stream to enter the narrow lake from the south side. Lithology of beds (from transmittal sheet of Hoare): Fossils come from massive gray crystalline limestone 100-120 feet thick, which weathers to a light gray color with a buff-colored fretwork. The limestone is probably somewhat siliceous and tuffaceous. The massive limestone horizon grades upward into 75-80 feet of interbedded buff-weathered limestone and black slates. The black slates contain gray-green beds of volcanic ash or tuff up to 3 inches thick. Above this horizon is at least 200 feet of black slaty siltstones and argillites and dark gray-green crystalline tuffs.; [Lat. 60.3838, Long. 158.9283, limestone (description from Karl et al., 2011)]
indeterminable crinoid fragments
50AHr290 (Mesozoic loc. 23166) , Goodnews Bay , 17 1/2 miles N. 79 1/2 deg. W. of outlet of Kagati Lake; 23 miles S. 25 1/2 deg. W. of west end of Eek Lake; 3 1/4 miles due north of Kanektok River at the point where the river turns southwestward. Near the top and on the north side of a peak which lies 1 1/2 to 2 miles northeast of a group of 3 small glacial lakes. Lithology of beds (from transmittal sheet of Hoare): Fossils occur in 15-20 feet of hard, dark gray, crystalline limestone which contains a few rounded chert pebbles. The limestone is associated with at least 300 feet of grayish and greenish quartzite and slaty argillites and siltstones with a minor amount of fine conglomerate. Directly overlying the limestone is at least 200 feet of calcareous greenstone agglomerate and fine-grained "cherty" greenstone. The greenstone is undoubtedly older than the limestone and quartzite and owes it postion to overturning or to a reverse fault. Apparently underlying the limestone and quartzite is a very thick section of highly micaceous graywacke, conglomerate and siltstone. However the cleavage in these rocks and observations in nearby areas indicate that the rocks under the greenstone are overturned and that the limestone and quartzite are older than the graywacke. The graywacke, siltstone and conglomerate have previously been dated as Middle Upper Cretaceous age.
Aucella crassicollis Keyserling
50AHr302 (Mesozoic loc. 23167) , Bethel , 19 3/4 miles S. 54 1/2 deg. W. of west end of Eek Lake; 27 miles N. 63 deg. W. of outlet of Kagati Lake; on the crest of a large isolated ridge which extends from the Middle Fork of Eek River northeastward across the North Fork of Eek River. Fossils may be obtained at many places along this ridge; present collection made about 13 miles from south end. Lithology of beds (from transmittal sheet of Hoare): Fossils occur through several hundred feet of interbedded coarse-grained graywacke, fine-grained conglomerate, calcareous graywacke, quartzitic graywacke and siltstones. The siltstones contain thin white beds of volcanic ash or tuff.
Aucella crassicollis Keyserling
Inoceramus sp.
50AHr230 (Mesozoic loc. 23163) , Taylor Mts , 15 1/2 miles S. 5 deg. E. of Gemuk Mountain; 9 1/8 miles S. 41 deg. E. of outlet of Aniak Lake; 2 1/2 miles S. 76 deg. W. of outlet of lake between Nishlik and Upnuk Lakes. About 1300 feet above narrow lake which lies between Lakes Upnuk and Nishlik on crest of a large ridge which projects northwestward from the main ridge between Lake Upnuk and the narrow lake just north of it. Lithology of beds (from transmittal sheet of Hoare): Fossils occur in a 10-15-foot bed of hard dark gray siliceous limestone which weathers to a dark brown color. The limestone overlies an undetermined amount of fine-grained dark graywacke with argillaceous interbeds and underlies a 10-foot bed of hard black cherty argillite with thin gray tuff bands. Above the black cherty argillite is an undetermined amount of the same type of graywacke and argillaceous rocks as lie below the limestone. All of the rocks are highly deformed; Lat. 60.3928, Long. 158.97771, graywacke-argillite (description from Karl et al., 2011)
Aucella cf. A. crassicollis Keyserling
50AHr240 (Not catalogued) , Taylor Mts , 16 3/4 miles S. 3 deg. E. of Gemuk Mountain; 9 1/2 miles S. 35 deg. E. of outlet of Aniak Lake; 3 1/8 miles S. 59 deg. W. of outlet of lake between Nishlik and Upnuk Lakes. About 2300 feet above Lake Upnuk on the south side and near top of the high ridge just north of lake. A small cirque lake lake lies about 1/4 mile south of and below the fossil horizon. Lithology of beds (from transmittal sheet of Hoare): Fossils occur in a thin bed of conglomeratic limestone which contains pebbles of chert and argillite up to 1 inch across. The limestone is interbedded with massive fine-grained graywacke with slaty interbeds. The rocks associated with the fossil horizon are thinly and evenly bedded--evidence for a quiet type of deposition. Overlying these rocks and structurally conformable is at least 200 feet of massive conglomeratic graywacke with very irregular bedding planes. Scattered cobble lenses occur in the graywacke in a most irregular fashion--evidence of a very rapid or "poured in" type of deposition; [Lat. 60.3838, Long. 158.0000, chert pebble conglomerate (description from Karl et al., 2011)]
fenestelloid bryozoans
polyporoid bryozoans
stenoporoid bryozoans
50AHr260 (Mesozoic loc. 23164) , Taylor Mts , 15 3/5 miles S. 11 deg. E. of Gemuk Mountain; 10 1/4 miles S. 10 1/2 deg. E. of outlet of Aniak Lake; 1 mile S. 53 1/2 deg. W. of outlet of lake between Nishlik and Upnuk Lakes. About 160 feet above the long narrow lake which lies between Lakes Upnuk and Nishlik; on the western side of the easternmost stream which enters the narrow lake, about 200 feet upstream of the point where bedrock is no longer exposed. Lithology of beds (from transmittal sheet of Hoare): Fossils occur in about 60 feet of black calcareous slates which contain thin white beds, thought to be volcanic ash. About 40 feet of the slaty rocks are hard and are probably tuffaceous or siliceous. The remaining 20 feet of the fossil horizon is composed of soft, almost friable slaty rocks. The well-developed fracture cleavage indicates that the rocks are overturned to the southwest. Overlying the black slates is at least 30 feet of hard crystalline limestone in beds 6 inches to 2 feet thick. Below the slates is 15 feet of coarsely-crystalline, probably tuffaceous, limestone containing shale fragments and then about 150 feet of interbedded dark gray calcareous argillite with white volcanic ash beds up to 1 inch thick and many thin gray limestone beds.; [Long. 60.3897, Long. 158.9206, limestone in black argillite (description from Karl et al., 2011)]
Halobia cf. H. septentrionalis Smith
50AHr364-A (Mesozoic loc. 23168) , Goodnews Bay , 27 3/4 miles S. 56 1/2 deg. W. of outlet of Lake Kagati; 14 3/4 miles N. 25 1/2 deg. W. of mouth of Klak Creek. 7/8 mile S. 30 deg. W. of a high sharp peak in the bend of the east fork of Nukluk Creek. Fossils came from talus near the top and on the north slope of the ridge which extends southwest of the high peak mentioned above, at a point a few hundred feet southwest of a low saddle which separates the peak from the ridge. Lithology of beds (from transmittal sheet of Hoare): Fossils occur in float derived from a horizon not over 20 feet thick that occurs in a section perhaps 200 feet thick of cherty, argillaceous and tuffaceous rocks containing scattered limestone lenses. All the fossils were found in the cherty and argillaceous rocks. None were found in the limestone. These rocks are associated with at least 200 feet of thin-bedded (beds 1"-6" thick) green and gray chert and several hundred feet of greenstones. The exact relationship between the three rock types has not been determined.
Pseudomonotis subcircularis Gabb
50AHr429 (Mesozoic loc. 23169) , Goodnews Bay , 30 3/4 miles S. 43 deg. W. of outlet of Kagati Lake; 7 3/4 miles N. 35 1/2 deg. W. of outlet of Goodnews Lake; on south side of a valley in which are two narrow lakes, between 1 and 2 miles long, which are at the head of two recurved tributaries to Goodnews River. Fossils occur about 200 feet above the marshy divide between the lakes on a spur which projects northwestward between the heads of the two lakes. (from original E&R report of Reeside) Lithology of beds (from transmittal sheet of Hoare): Fossils occur through an 18-inch zone which has a 1" bed of fine conglomerate at its base. This zone is interbedded with an undetermined amount of well-bedded, hard dark graywacke. [Elder and Miller, 1991, p. 9 give following description: "Goodnews Bay (C-5) 1:63360 quadrangle. Ridge south of Awayak Lake. Elevation 1500 ft (457 m). Latitude: 59 deg. 33.63' N; Longitude: 160 deg. 44.27' W; Township: 7S; Range 67W; Section 19; NW quarter; Collector: J. Hoare, 1950. Field Identifier: 50AHr429."]
Aucella crassicollis Keyserling
50AHr590 (Mesozoic loc. 23170) , Goodnews Bay , 15 1/2 miles S. 48 deg. W. of outlet of Kagati Lake; 11 1/2 miles S. 70 deg. E. of mouth of Klak Creek; 15 3/4 miles N. 6 1/2 deg. E. of head of Goodnews Lake. Fossils occur near the southeast end of a ridge which lies north of a lake about 2 miles long which drains into Klak Creek. The ridge starts about the center of the lake and extends northwestward. Fossil in float about 900 feet above lake level and 20 feet below the crest of the ridge. Lithology of beds (from transmittal sheet of Hoare): Fossils occur in float derived from well-bedded vari-colored cherts and tuffs. The lithology appears to be similar to that described above under 50AHr364-A. [Silberling et al., 1997, p. 18-19 provide following description: Kuskokwim region, southwestern Alaska; lat 59 deg. 44'02" N., long 160 deg. 27'02" W.; 15 1/2 miles S. 48 deg. W. of outlet of Kagati Lake; 11 1/2 miles S. 70 deg. E. of mouth of Klak Creek; 15 3/4 miles N., 6 1/2 miles E. of head of Good News Lake. Fossils occur near the southeast end of a ridge that lies north of a lake about 2 miles long that drains into Klak Creek; the ridge starts about the center of the lake and extends northwestward; fossils in float about 900 feet above lake level and 20 feet below the crest of the ridge. Coll.: J.M. Hoare, August 18, 1950, field No. 50AHr590. Recollected by W.L. Coonrad and J.M. Hoare, 1975, field No. GC4-1122; Goodnews C-4 quadrangle; NE 1/4 sec. 23, T. 5 S., R. 66 W. [Goodnews terrane]]
Pseudomonotis subcircularis Gabb
50AHr555-A (Mesozoic loc. 23171) , Goodnews Bay , 3 1/3 miles N. 32 deg. E. of outlet of Lake Kagati; 23 1/4 miles S. 22 1/2 deg. E. of the outlet of Eek Lake; 2 1/2 miles S. 81 1/2 deg. W. of Mount Oratio. Near the northwest end of the ridge on the south side of tributary to Eek River. Lithology of beds (from transmittal sheet of Hoare): Fossils (pelecypods) occur in an impure, red and gray limestone about 10 feet thick interbedded with argillaceous rocks. The rocks are considerably folded and thickness of the section could not be determined.
Aucella sp., probably A. crassicollis Keyserling