Sample Detail of
Sample: Sample No. 92AD50C -- USGS No. 32447-PC
Locality: Field No. 92AD50C
Description: Howard Pass C-5. Lat. 68o 44'45" N., Long. 158o 55'35" W. Possibly graded-bedded, partly silicified limestone rich in crinoid columnals. Thin section is medium- to coarse-grained, poorly sorted, diverse skeletal grainstone. Bioclasts chiefly crinoid ossicles (20-40 percent), along with lesser bryozoans, foraminifers, siliceous sponge spicules, brachiopod fragments, and ostracodes; lithoclasts include glauconite, micrite, noncalcarous (locally spiculitic) mudstone and phosphate. Collected approx. 15 m below top of approx. 50-60-m-thick section of unit Mlri. Stratigraphic up seems to be to the south, based on sedimentary structures; section could be structurally thickened. If section is depositionally continuous, 92AD52A (loc. 3) should be near botton. This is the furthest northwest exposure of unit Mlri in the Howard Pass 1:250,000 quadrangle. (description from Dover et al., 2004, p. 29 (Table 1)); [Howard Pass C-5. 68°44'47", 158°55'35". Possibly graded-bedded, partly silicified limestone rich in crinoid columnals.
Collected ~15 m below top of ~50-60 m-thick section of Ipnavik facies of Lisburne Group. Stratigraphic up seems to be to the south, based on sedimentary structures (but could be structually repeated). If section is not repeated, 92AD52A should be near top and 50C should be near bottom.
Collected at 760+ m elevation, on top of small knob, ~2 miles due west of Jubilee Creek and ~3/4 mile east of hill 815 m; center sec. 13, T. 8 S., R. 30 W.
This is the furthest northwest exposure of Ipnavik facies in the Howard Pass quadrangle. (description from Harris E&R report dated March 7, 1995, shipment A-95-3)]
Location: Alaska Quadrangle: Howard Pass C-5
Township&Range: 8 S. 30 W. Section: 13
Lat.: 68o44'45 " Long.: 158o55'35 "
Reference
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
Report by: Jim Dover , Irv L. Tailleur , Julie A. Dumoulin
Age: Osagean (No older than middle Osagean)
Formation: Lisburne Group (Rim Butte unit of Lisburne Group of Dumoulin and others (1993) (Mississippian))
CAI:Min: 1.5 - Max: 2
Comment:Age: No older than late Early Mississippian; Sc. anchoralis-Do. latus Zone (middle Osagean) along with redeposited Kinderhookian and possibly early Osagean conodonts. This species association and mixture of biofacies and ages is characteric of the Rim Butte unit.

Biofaces: Mixed biofacies and age; outer shelf or deeper water depositional setting, probably a turbidite.

CAI=1.5-2

Shown as locality 2 on Sheet 2; map unit: Mlri

Processed 10.1 kg of rock.

Occurrence(s)
No. Group Name Qty Notes
1 Conodonts 1 Pa frament Bactrognathus excavatus Branson and Mehl all conodonts identified by A.G. Harris
2 Conodonts 16 Pa elements Bispathodus stabilis (Branson and Mehl) .....
3 Conodonts ..... or Bi. utahensis Sandberg and Gutschick
4 Conodonts 1 "Hindeodella" segaformis Bischoff s.f. bar fragment
5 Conodonts Idioprioniodus conjunctus (Gunnell), 6 Pa, 3 M, 6 Sa, and 18 Sb-Sc elements
6 Conodonts Kladognathus sp., 3 P, 8 M, 4 Sa, and 7 Sb-Sc elements
7 Conodonts 17 Pa elements Polygnathus communis cairna Hass
8 Conodonts 2 Pa fragments Polygnathus spp. indet.
9 Conodonts 1 Pa element fragment Pseudopolygnathus pinnatus (Voges)
10 Conodonts 2 Scaliognathus praeanchoralis Lane, Sandberg, and Ziegler fragments
11 Conodonts 6 Pb elements Scaliognathus sp. indet.
12 Conodonts 48 indet. bar, blade, and platform fragments
13 Conodonts 13 Pa elements Pseudopolygnathus primus Branson and Mehl Redeposited late Kinderhookian conodonts
14 Conodonts 3 incomplete Pa elements Siphonodella isosticha (Cooper) Redeposited late Kinderhookian conodonts
15 Conodonts 5 Pa element fragments Siphonodella sp. indet. Redeposited late Kinderhookian conodonts
16 Conodonts 8 Pa elements Gnathodus punctatus (Cooper) Redeposited late Kinderhookian or early Osagean conodonts
17 Conodonts Unassigned elements: 5 Pb (3 morphotypes) and 9 M (4 morphotypes)

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 (no older than middle Osagean)
Formation: Lisburne Group (Lisburne Group (Ipnavik facies))
CAI:Min: 1.5 - Max: 2
Comment:Age: No older than Scaliognthus anchoralis-Doliognathus latus Zone (middle Osagean) with redeposited Kinderhookian and possibly early Osagean conodonts. This species association and mixture of biofacies and ages is characteristic of the Rim Butte unit (Ipnavik allochthon).
Biofacies: Mixed biofacies and age; outer shelf or deeper water depositional setting, probably a turbidite.
CAI = 1.5-2

10.1 kg of rock processed (1540 g of +20 mesh and 372 g 20-140 mesh insoluble residue).
Heavy-mineral concentrate: chiefly phosphatized composite grains, phosphatic brachiopod fragments, unpicked conodont fragments and minor iron oxides.

Occurrence(s)
No. Group Name Qty Notes
1 Conodonts 1 Pa element fragment Bactrognathus excavatus Branson and Mehl
2 Conodonts 16 Pa elements Bispathodus stabilis (Branson and Mehl) .....
3 Conodonts ... or Bispathodus utahensis Sandberg and Gutschick
4 Conodonts 1 "Hindeodella" segaformis Bischoff s.f. bar fragment
5 Conodonts Idioprioniodus conjunctus (Gunnell) 6 Pa, 3 M, 6 Sa, and 18 Sb-Sc elements
6 Conodonts Kladognathus sp. 3 P, 8 M, 4 Sa, and 7 Sb-Sc elements
7 Conodonts 17 Pa elements Polygnathus communis cairna Hass
8 Conodonts 2 Pa fragments Polygnathus spp. indet.
9 Conodonts 1 Pa element fragment Pseudopolygnathus pinnatus (Voges)
10 Conodonts 2 Scaliognathus praeanchoralis Lane, Sandberg, and Ziegler fragments
11 Conodonts 6 Pb elements Scaliognathus sp. indet.
12 Conodonts 48 indet. bar, blade, and platform fragments
13 Conodonts REDEPOSITED LATE KINDERHOOKIAN CONODONTS:
14 Conodonts 13 Pa element Pseudopolygnathus primus Branson and Mehl
15 Conodonts 3 incomplete Pa elements Siphonodella isosticha (Cooper)
16 Conodonts 5 Pa element fragments Siphonodella sp. indet.
17 Conodonts REDEPOSITED LATE KINDERHOOKIAN OR EARLY OSAGEAN CONODONTS
18 Conodonts 8 Pa elements Gnathodus punctatus (Cooper)
19 Conodonts UNASSIGNED ELEMENTS: 5 Pb (3 morphotypes) and 9 M (4 morphotypes)