| Sample: |
Sample No. 92AD70A -- USGS No. 12469-SD
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| Locality: |
Field No. 92AD70A
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| Description: |
Howard Pass B-5. Lat. 68o 24'47" N., Lat. 158o 53.30" W. Sample from 25-cm-thick bed of very sooty, fossiliferous (sparse crinoids and gastropods) micritic limestone with limy shale partings. Thin section is lime mudstone containing sparse, 2-mm-thick laminae of skeletal wacke/packstone; bioclasts include crinoid ossicles and calcareous sponge spicules. Collected approx. 4 m above base of approx. 10-m-thick outcrop of unnamed Devonian unit. Lithology is similar and age is equivalent to that at 92AD28A (loc. 74). Heavy-mineral concentrate includes phosphatic brachiopod fragments. (description from Dover et al., 2004, p. 46 (Table 1)); [Howard Pass B-5. 68°24'48", 158°53'55". 25-cm-thick bed of very sooty, fossiliferous (sparse crinoids and gastropods) micritic limestone with limy shale partings. Collected ~4 m above base of ~10-m-thick outcrop of unnamed Devonian unit. Lithology (and age?) = ~92AD28A section.
Collected on east side of Buccaneer Creek Creek, ~1/2 mile north of junction of Buccaneer Creek and unnamed tributary and 2 1/4 miles south of hill 705 m, western Brooks Range. (description from Harris E&R reports dated Jan. 25, 1995 (Shipment no. A-95-3a) and March 17, 1995 (Shipment no. A-95-3)] |
| Location: |
Alaska Quadrangle: Howard Pass B-5
Lat.: 68o24'47 " Long.: 158o53'30 " |
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Reference
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| Title: |
Geologic and fossil locality maps of the west-central part of the Howard Pass Quadangle and part of the adjacent Misheguk Mountains Quadrangle, western Brooks Range, Alaska
,
2004
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| Report by: |
Jim Dover
,
Irv L. Tailleur
,
Julie A. Dumoulin
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| | Age: | Eifelian-Givetian (early-middle Middle Devonian (middle Eifelian - early Givetian)) |
| Formation: | Unnamed (Unnamed limestone (Devonian)) |
| CAI: | Min: 3 |
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| Comment: | Age: early-middle Middle Devonian; To. k. australis Zone to Lower Po. varcus Subzone (middle Eifelian-early Givetian). This sample matches the conodont assemblages in 92AD28A-4 and 92AD28A-22 (loc. 74) rather well. Brachiopods of Late Devonian age (station 51T123, coll. 51ATr441; USGS coll. 3367) reported from this general locality by J.T. Dutro, Jr., USGS, 1953, unpub. report. Biofacies: Polygnathid. The polygnathids are abundant, relatively well preserved, and all elements of the apparatus are present. The conodonts have not been hydraulically sorted. Probably quiet-water, middle-shelf depositional environment. Shown as locality 88 on Sheet 2; map unit: Dl CAI=3 Processed 11.0 kg of rock. |
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| Title: |
Report on Referred Fossils
,
1995
(03/17)
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Analysis of all samples is given in the accompanying 16-page table. The range of biostratigraphically important samples is shown on the accompanying diagram. The heavy-mineral concentrates were analyzed by Nancy Stamm; the residues have been returned to Julie Dumoulin. Please note a few (~4 samples have heavy-mineral concentrates that include chalcopyrite and bornite). |
| Report by: |
Anita G. Harris
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| Referred by: |
Julie A. Dumoulin
,
J. H. Dover
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| | Age: | Eifelian-Givetian (middle Eifelian - early Givetian) |
| Formation: | Unnamed (unnamed Devonian unit) |
| CAI: | Min: 3 |
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| Comment: | Age: To. australis Zone to Lower Po. varcus Subzone (middle-Eifelian-early Givetian; early-middle Middle Devonian). This sample matches the conodont assemblages in 92AD28A-4 and 92AD28A-22 very well but has more integrity.
Biofacies: Polygnathid, this sample is quintessential polygnathid biofacies. The polygnathids are abundant, relatively well preserved, and all elements of the apparatus are present. The conodonts have not been hydraulically sorted. Probably quiet water, middle-shelf depositional environment.
CAI = 3 11.0 kg of rock processed (220 g of +20 mesh and 4 g 20-140 mesh insoluble residue).
Heavy-mineral concentrate: chiefly iron oxides, phosphatic brachiopod fragments and pyritized composite grains. |
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| Title: |
Report on Referred Fossils
,
1995
(01/25)
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All conodont analyses and samples and residue weights are given in the attached tables. The age range of all samples is graphically shown on the accompanying diagram. Please give a copy of this report to Jim Dover and anyone else on the Howard Pass project that needs these data. I will do all the Carboniferous samples while in Florida. |
| Report by: |
Anita G. Harris
|
| Referred by: |
Julie A. Dumoulin
|
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| | Age: | Eifelian-Givetian (middle Eifelian - early Givetian) |
| Formation: | Unnamed (unnamed Devonian unit) |
| CAI: | Min: 3 |
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| Comment: | Age: T. australis Zone to Lower Po. varcus Subzone (= middle Eifelian to early Givetian; =early-middle Middle Devonian). This sample matches the conodont assemblages in 92AD28A-4 and -22 very well but has more integrity.
Biofacies: Polygnathid biofacies; this sample is quintessential polygnathid biofacies. The polygnathids are abundant, relatively well preserved and all elements of the apparatus are present. The conodonts have not been hydraulically sorted. Probably quiet water, middle shelf depositional environment.
CAI=3 Heavy-mineral concentrate: chiefly iron oxides, phosphatic brachiopod fragments and pyritized composite grains.
Wgt. (kg) 11.0; >20 mesh insol. res., (grams) 220; 20-200 mesh insol. res., (grams) 4 |
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