Sample: |
Sample No. 92AD25E -- USGS No. 12458-SD
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Locality: |
Field No. 92AD25E
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Description: |
Howard Pass B-4. Lat. 68o 21'00" N., Long. 158o 16'15" W. Nodular, 1- to 2-cm-thick beds of fine-grained skeletal lime wackestone. Thin section is skeletal wacke/packstone; diverse bioclasts include crinoid ossicles (to 3 mm in diameter), various types of algae (including Girvanella sp.), ostracodes, gastropods, calcispheres, echinoid spines, and fragments of stromatoporoids, bryozoans, and trilobites. Matrix is peloidal and locally dolomitized, and contains minor detrital quartz and altered volcanic(?) lithic clasts. Collected from a discrete approx. 10 x 20 m block of unnamed Devonian limestone within Copter Peak basalt unit of Siniktanneyak mafic complex. Corals and stromatoporoids of Frasnian age were previously reported from this locality (table 4; fossil loc. 6 of Nelson and Nelson, 1982). (description from Dover et al., 2004, p. 48 (Table 1)); [Howard Pass B-4. 68°21'04", 158°16'20". Nodular, 1-2 cm-thick beds of fine-grained skeletal lime wackestone. Collected from a discrete ~ 10 m x 20 m block of unnamed Devonian limestone rocks depositionally(?) associated with Siniktanneak mafic complex. Collected from southwest side of unnamed tributary to and ~ 1.5 miles northwest of Makpik Creek, and ~3 miles northeast of Siniktanneak Mountain, western Brooks Range; sec. 19, T. 34 N., R. 3 E. (from Harris E&R report dated March 17, 1995; Shipment A-95-3 and Harris E&R report dated Jan. 25, 1995, Shipment A-95-3a)] |
Location: |
Alaska Quadrangle: Howard Pass B-4 Township&Range: 34 N. 3 E. Section: 19 Lat.: 68o21'00 " Long.: 158o16'15 " |
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Reference
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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
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J. H. Dover
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| Age: | Frasnian (middle Frasnian) |
Formation: | Unnamed (unnamed Devonian limestone) |
CAI: | Min: 2 - Max: 2.5 |
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Comment: | Age: Lower Pa. hassi Zone to Upper Pa. rhenana Zone; = middle Frasnian; =middle early Late Devonian. See attached chart showing conodont zones of the Frasnian. Biofacies: Polygnathid biofacies; the taphonomy of the conodonts indicates postmortem transport within this biofacies as most ramiform elements have been winnowed out; the characteristic of Po. pacificus suggests a middle to outer shelf depositional environment. The polygnathids have not been moved beyond their biofacies as juveniles, subadults, and adults are present in this assemblage. CAI 2-2.5 Heavy mineral concentrate: chiefly ferruginous argillaceous grains, weathered and fresh anhedral pyrite. |
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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
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Referred by: |
Julie A. Dumoulin
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| Age: | Frasnian (middle Frasnian) |
Formation: | Unnamed (unnamed Devonian limestone) |
CAI: | Min: 2 - Max: 2.5 |
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Comment: | Age: Lower Pa. hassi Zone to Upper Pa. rhenana Zone; = middle Frasnian; = middle early Late Devonian. See attached chart showing conodont zones of the Frasnian. Biofacies: Polygnathid biofacies; the taphonomy of the conodonts indicates postmortem transport within this biofacies as most ramiform elements have been winnowed out; the characteristics of Po. pacificus suggests a middle to outer shelf depositional environment. The polygnathids have not moved beyond their biofacies as juveniles, subadults, and adults are present in this assemblage. CAI = 2-2.5 Heavy-mineral concentrate: chiefly ferruginous argillaceous grains, weathered & fresh anhedral pyrite. Wgt. (kg) 6.4; >20 mesh insol. res., (grams) 280; 20-200 mesh insol. res., (grams) 115 |
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