Sample: |
Sample No. 92AD59A -- USGS No. 32452-PC
|
Locality: |
Field No. 92AD59A
|
Description: |
Howard Pass C-5. Lat. 68o 35'45" N., Long. 158o 27'20" W. Sample from 3- to 6-cm-thick bed of fine-grained, dark-gray, very light gray to medium-gray-weathering, very fetid limestone that has a ghostly texture of black spheroids (calcitized radiolarians?). Thin section is calcite crystal mosaic that contains relict, carbonate-replaced radiolarians. Sample taken approx. 3 m below top of approx. 30-m-thick section (poorly exposed and could be folded) mostly black chert (and (or) silicified mudstone) but including silty bands and spicules and approx. 20-30 percent limestone. Uppermost part of section is light-gray chert that contains radiolarians of Mississippian? age (92AD59G, table 2). (description from Dover et al., 2004, p. 31 (Table 1)); [Howard Pass C-5. 68°35'48", 158°27'25". 3-6 cm-thick-bedded, fine-gray, very light-gray- to medium-gray-weathering, very fetid limestone with ghostly texture of black spheroids (calcitized radiolarians?). Collected from Mississippian "deeper-water facies" of the Lisburne, ~3 m below top of ~ 30 m(?)-thick section (poorly exposed and could be folded) comprised mostly of black chert (and/or silicified mudstone) with silty bands and spicules and ~20-30% limestone. Uppermost part of section is light-gray radiolarian chert. Collected from NW side of small knob (~660 m+ high), ~1.5 miles SE of junction of Kiligwa River and Drenchwater Creek; NE1/4NE1/4 sec. 9, T. 10 S., R. 29 W. (description from Harris E&R report dated March 17, 1995; shipment no. A-95-3)] |
Location: |
Alaska Quadrangle: Howard Pass C-5 Township&Range: 10 S. 28 W. Section: 9 Lat.: 68o35'45 " Long.: 158o27'20 " |
|
|
Reference
|
Occurrence(s) |
No. |
Group |
|
Name |
Qty |
Notes |
1 |
Conodonts |
|
2 Pa element fragments Gnathodus pseudosemiglaber Thompson and Fellows? |
|
All conodonts identified by A.G. Harris. All conodonts partly coated and invaded by organic matter. |
2 |
Conodonts |
|
Unassigned elements: 2 Pb (2 morphotypes), 1 digyrate Pb? of Osagean morphotype, 1 Sa, and 1 Sc |
|
|
3 |
Conodonts |
|
42 indet. bar, blade and platform fragments |
|
|
|
|
Title: |
Report on Referred Fossils
,
1995
(03/17)
|
|
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
|
Referred by: |
Julie A. Dumoulin
,
J. H. Dover
|
|
|
| Age: | Osagean-Meramecian (late Osagean - Meramecian, probably late Osagean) |
Formation: | Lisburne Group (Mississippian "deeper water facies" of the Lisburne Group) |
CAI: | Min: 1.5 - Max: 2 |
|
|
|
|
Comment: | Age: Lower G. texanus Zone through Lower Cavusgnathus Zone (=late Osagean through Meramecian) on the basis of conodonts in underlying sample (92AD59AA); probably late Osagean. Biofacies: Indeterminate (too few conodonts); mid-shelf or deeper water depositional environment. CAI = 1.5-2 8.8 kg of rock process (580 g of +20 mesh and 90 g 20-140 mesh insoluble residue). Heavy-mineral concentrate: chiefly phosphatized argillaceous grains and bioclasts and minor iron oxides. |
Occurrence(s) |
No. |
Group |
|
Name |
Qty |
Notes |
1 |
Conodonts |
|
all conodonts partly coated and invaded by organic grunge. |
|
|
2 |
Conodonts |
|
2 Pa element fragments Gnathodus pseudosemiglaber Thompson and Fellows? |
|
|
3 |
Conodonts |
|
UNASSIGNED ELEMENTS: |
|
2 Pb (2 morphotypes), 1 digyrate Pb? of Osagean morphotype, 1 Sa, and 1 Sc |
4 |
Conodonts |
|
42 indet. bar, blade, and platform fragments |
|
|
|
|
|
|