Reference Detail of

Report on Referred Fossils
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Stratigraphic range: Upper Triassis and ?
Kinds of fossils: Marine invertebrates
Quadrangle or area: Nabesna 1:250,000
Shipment No.: A-68-12
Referred by: Richter, Donald H.
Report prepared by: Silberling, Norman J.
Date: 11/13/1968


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Brief statement of problem and remarks (from collector):
The Triassic rocks in the eastern Alaska Range consist of a massive, thick-bedded fossil-poor limestone overlain unconformably by thin-bedded, locally extremely fossiliferous, limestone. Fossil suites from both limestone units are being submitted. Fossils from the massive limestone collected last year west of the present study area indicate a Triassic age (Grant rept. 3/22/68 and Duncan, rept. 4/19/68). The thin-bedded limestone contains Monotis subcircularis and hence is late Triassic (Silberling, rept. 11/7/67). Corroboration of our Triassic age assignemtn and a more specific age for the massive limestone is desired. Refer to my transmittal memo to Norm Sohl for more general information on the area.
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68-ARh-52 , Nabesna , Nabesna B-4 quad. Lat. 62 deg. 23.0' N; Long. 142 deg. 40.8'W. Elev. 4000 feet in SW 1/4 sec. 17, R15E, T7N. From thin limestone beds (1-2') in massive limestone unit. (description from transmittal sheet of Richter dated Sept. 27, 1968)
smooth terebratuloid brachiopods
other shell fragments
68-ARh-162 , Nabesna , Nabesna B-4 quad. Lat. 62 deg. 18.8'N; Long. 142 deg. 57.8'W. Elev. 300 feet in SW 1/4 sec. 11, R12E, T6N. Massive limestone unit.
Crinoid columnals
indeterminate shell fragments
68ARh-163 , Nabesna , Nabesna B-4 quad. Lat. 62 deg. 19.3'N; Long. 142 deg. 58.0'W. Elev. 2800 feet in NE 1/4 sec. 10, R13E, T6N. Massive limestone unit. (description from transmittal sheet of Richter dated Sept. 27, 1968)
cidaroid echinoid spines
nondiagnostic fragments of pelecypods
nondiagnostic fragments of gastropods
68-ARh-201 , Nabesna , Nabesna B-4 quad. Lat. 62 deg. 17.3'N; Long. 142 deg. 58.3'W., elev. 3500 feet in NW 1/4 sec. 22, R13E, T6N. Massive limestone unit. (description from transmittal sheet of Richter dated Sept. 17, 1958)
Indeterminate smooth terebratuloid brachiopods
68-ARh-256 , Nabesna , Nabesna A-3 quad. Lat. 62 deg. 13.7'N; Long. 142 deg. 24.5'W. Elev. 4500 feet in SW 1/4 sec. 10, R16E, T6N. Thin-bedded limestone unit. (description from transmittal sheet of Richter dated Sept. 27, 1968)
Cidaroid echinoid spines
68-ARh-302 , Nabesna , Nabesna C-5 quad. Lat. 62 deg. 35.9'N; Long. 143 deg. 09.1'W. Elev. 4800 feet in SW 1/4 sec. 34, R12E, T10N. Base of thin-bedded limestone unit. (description from transmittal sheet of Richter dated Sept. 27, 1968)
Indeterminate shell fragments
68-ARh-55 , Nabesna , Nabesna B-4 quad. Lat. 62 deg. 23.0'N; Long. 142 deg. 40.6'W. Elev. 4000 feet in SW 1/4 sec. 17, R15"E, T7N. From thin-bedded limestone unit. Dark argillite-chert interbedded with limestone.
Monotis? sp.
68-ARh-224 (Mesozoic loc. M5090) , Nabesna , Nabesna B-4 quad. Lat. 62 deg. 19.6'N; Long. 142 deg. 35.5'W. Elev. 3700 feet in SW 1/4 sec. 2, R15E, T6N. Thin-bedded limestone unit. (description from Richter transmittal sheet of Sept. 27, 1968)
Halobiid pelecypods
68-ARh-235 (Mesozoic loc. M5091) , Nabesna , Nabesna B-4 quad. Lat. 62 deg. 17.4'N; Long. 142 deg. 30.8'W. Elev. 5800 feet in NE 1/4 sec. 19, R16E, T6N. Thin-bedded limestone unit.
Monotis cf. M. subcircularis Gabb
68-ARh-234 (Mesozoic loc. M5092) , Nabesna , Nabesna B-4 quad. Lat. 62 deg. 17.3'N; Long. 142 deg. 31.5'W. Elev. 6200 feet in NW 1/4 sec. 19, R16E, T6N. Massive limestone unit. (description from transmittal sheet of Richter dated Sept. 27, 1968.
suggestive of the hydrozoan Heptastylis