Reference Detail of

Report on Referred Fossils
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Stratigraphic range: Upper Triassic and indeterminate
Kinds of fossils: Marine invertebrates
Quadrangle or area: Talkeetna D-1; Mt. McKinley A-1; Healy A-6
Shipment No.: A-77-12M
Referred by: Reed, Bruce
Report prepared by: Silberling, Norman J.
Date: 03/15/1977

This report treats the 36 collections that are included in Groups B and C on the transmittal forms. Those collections that contain recognizable, reasonably age-diagnostic fossils are all of late Norian (late Late Triassic) age. From our understanding of the stratigraphic section on strike north-east of the Eldridge Glacier in the Healy Quadrangle, rocks of this age from the uppermost part of the red-bed unit and the lower part of an intergradational but stratigraphically overlying unit of brown calcareous andstone and argillite. The conspicuou limestone and basalt unit stratigraphically underlies the red beds, but it is evidently still no older than Late Triassic. In the Healy (A-6) Quadrangle most of the Triassic rocks above the structually highest serpentine belt on the ridge northeast of Partin Creek are demonstrably overturned.

Thin sections of limestone 76ANs55G, 76ACo45, 46A through -46D, 76ANs57A, and 76AR240 are being prepared. If anything diagnostic appears in them, I will let you know. Your thin sections and their corresponding rocks samples are being returned. Otherwise all of the material, except for that assigned USGS Mesozoic locality numbers, has been discarded.

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76AR198 , Talkeetna , Elevation 5,020 feet, 1.25 miles east of Swift Creek.
Cidarid echinoid spines in laminated (foliated?) gray limestone
76AR199 , Talkeetna , Elevation 4,150 feet, 1.75 miles east of Swift Creek. Request for Paleo. Analysis form says from "Massive limestone with abundant fossil debris. Unit overlain by gray argillite and siltstone. Thought to be same limestone as 76AR198"
echinodermal debris
poorly preserved, silicified, questionable coral fragments
76AR238 , Talkeetna , Elevation 4,720 feet, 1.5 miles northeast of the Hidden River.
indeterminate ribbed bivalve
76ACo47A and B , Talkeetna , Elevation 4,900 feet, 1.5 miles east of Swift Creek.
coarsely silicified and indeterminate corals
76AR49 , Talkeetna , Elevation 5,200 feet, 1.5 miles east of Swift Creek. Coral and pelecypod fragments in the same limestone as 76ACo47A, 76ACo47B.
possible spongiomorph, but too poorly preserved for positive identification
76ACo50 , Talkeetna , Elevation 4,100 feet, 1.5 miles east of Swift Creek
indeterminate large solitary coral
abundant echinodermal debris
76ACo53 , Talkeetna , Elevation 4,200 plus feet, 1.5 miles east of Swift Creek.
poorly preserved branching coral, possiblyThecosmilia
76ANs58A , Talkeetna , Elevation 5,300 feet, 1.75 miles east of Swift Creek.
crinoid columnal
76ANs58D (USGS Mesozoic loc. M6653) , Talkeetna , Elevation 5,200 feet, 2 miles east of Swift Creek.
Heterastridium
inderminate bivalve fragments
indeterminate gastropod fragments
76ANs58F , Talkeetna , Elevation 4,960 feet, 2.5 miles east of Swift Creek.
crinoid columnals
76ANs58G , Talkeetna , Elevation 4,300 feet, 2.5 miles east of Swift Creek. Elevation 4,300 feet, 2.5 miles east of Swift Creek.
large micritized shell fragments
possible bryozoan
76ACo64 , Talkeetna , Elevation 4,8oo feet, 1.25 miles southwest of the Eldgridge Glacier.
Molds of calcareous lumps in sheared argillite. Not recognizably organic in origin.
76ACo67 (USGS Mesozoic loc. M6654) , Talkeetna , Elevation 4,500 feet, 1.25 miles southwest of the Eldridge Glacier.
Heterastridium?
76ANs59A (USGS Mesozoic loc. M6655) , Talkeetna , Elevaton 4,600 feet, 1 mile southwest of the Eldridge Glacier.
Coarsely silicified colonial coral fragments
76ANs59B (USGS Mesozoic loc. M6656) , Talkeetna , Elevation 4,500 feet.
Bivalve impressions, resemble Up. Triassic genus Septocardia
76ANs54A , Talkeetna , Elevation 4,000 feet, 0.5 miles west of Swift Creek.
Possibly Heterastridium, but too sheared and recrystallized to be certain.
76AR221 , Talkeetna , Elevation 4,300 feet, 0.5 miles northwest of Skihi Creek.
crinoidal bioclast
76AR223 , Talkeetna , Elevation 3,200 feet, 0.5 miles southeast of Skihi Creek.
Nothing recognizably organic
76ANs53C (USGS Mesozoic loc. M6657) , Talkeetna , Elevation 5,110 feet, 2.25 miles southwest of the Eldridge Glacier.
Monotis subcircularis Gabb
76ANs53F , Talkeetna , Elevation 4,950 feet, 2.25 miles southwest of the Eldridge Glacier.
large bivalve shell fragment
molds of star-shaped crinoid columnals in slaty siltstone
76ANs53G , Talkeetna , Elevation 4,950 feet, 2.25 miles southwest of Eldridge Glacier.
fragment of a large solitary coral
fragment of thick prismatic bivalve shell or an originally aragonitic vein
76ANs53H , Talkeetna , Elevation 4,950 feet, 2 miles southwest of the Eldridge Glacier.
Heterastridium sp.
76ANs53K , Talkeetna , Elevation 4,800 feet, 2 miles southwest of the Eldridge Glacier.
echinoid spine
76ANs53M , Talkeetna , Elevation 4,600 feet, 2 miles southest of the Eldridge Glacier.
indeterminate bivalves
76ANs55G , Talkeetna , Elevation 5,050 feet, 2.5 miles northwest of Buskin Glacier
echinodermal (probably crinoidal) debris visible in hand specimen
76ACo45 , Talkeetna , Elevation 3,850 feet, 1.5 miles southwestof the Eldridge Glacier
echinodermal (probably crinoidal) bioclasts visible in hand specimen
76ACo46A , Talkeetna , Elevation 3,800 feet, 1.5 miles southwest of the Eldridge Glacier.
may be fragment of colonial coral
76ACo46B, C, and D , Talkeetna , Elevation 3,540 feet, 1 miles southwest of the Eldridge Glacier
76ANs57A (USGS Mesozoic loc. M6658) , Talkeetna , Elevation 5,100 feet, 1.5 miles southwest of the Eldridge Glacier
Heterastridium? sp.
76ANs57B (USGS Mesozoic loc. M6659) , Talkeetna , Elevation 4,890 feet, 1.5 miles southwest of the Eldridge Glacier.
Monotis sp. indet.
76AR240 (USGS Mesozoic loc. M6660) , Talkeetna , Elevation 2,100 feet on the Eldridge Glacier
Heterastridium
Cassianella
variety of pectenacid forms
76AR214 (USGS Mesozoic loc. M6661) , Mt Mc Kinley , Elevation 5,950 feet, 2 miles northeast of the Eldridge Glacier
Heterastridium?
fragment of large solitary coral
bivalve shell fragments
Septocardia?
echinodermal debris
76AR215 (USGS Mesozoic loc. M6662) , Healy , On ridge above glacer at the head of Shotgun Creek
nautiloids