Sample Detail of
Sample: Sample No. 92AD214-44 -- USGS No. 32465-PC
Locality: Field No. 92AD214-44
Description: Howard Pass B-5. Lat. 68o 23'10" N., Long. 158o 54'00" W. Similar lithology to 92AD214-1.5, but collected from a 20-cm-thick bed scoured into black fissile shale; sample taken 44 m above base of approx. 85-m-thick measured section. Thin section is fine- to medium-grained skeletal grainstone, cemented chiefly with calcite but locally with chert. Diverse bioclasts include crinoid ossicles (20-50 percent of bioclasts), foraminifers (5-10 percent), ostracodes, brachiopods, and echinoid spines. Some bioclasts are micritized; others are partly or completely replaced by silica or pyrite. Minor brown mud clasts and <1 percent disseminated quart silt. Base of grainstone beds is scoured into dark brown shale containing 5-10 percent disseminated quartz silt. Heavy-mineral concentrate includes a pyritized ostracode steinkern. (description from Dover et al., 2004, p. 47 (Table 1)); [Howard Pass B-5. 68°23'13", 158°54'00". Has similar lithology to 92AD215-1.5, but collected from a 20-cm-thick bed scoured into black, fissile shale.
From same locality as above ("referring to 92AD215-1.5 and -18.5"). (description from Harris E&R report dated March 17, 1995; shipment no. A-95-3)]
Location: Alaska Quadrangle: Howard Pass B-5
Township&Range: 12 S. 30 W. Section: 22
Lat.: 68o23'10 " Long.: 158o54'00 "
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 (late Early Mississippian (middle Osagean))
Formation: Lisburne Group (Rim Butte unit of Lisburne Group of Dumoulin and others (1993) (Mississippian))
CAI:Min: 2.5 - Max: 3
Comment:Age: late Early Mississippian Sc. anchoralis-Do. latus Zone (middle Osagean). Mestognathus praebeckmanni is a rare conodont. It occurs in another sample from a turbidite within deeper water facies of the Lisburne Group (Akmalik Chert) in the central Howard Pass quadrangle (table 4, loc. 32; Dumoulin and others, 1993, table 1 and fig. 7K-M).

Biofacies: Mixed biofacies; probable slope or deeper water depositional environment with admixture from the shallowest-water mestognathid biofacies.

Shown as locality 89 on Sheet 2; map unit: Mlri

CAI=2.5-3

Processed 6.6 kg of rock.

Occurrence(s)
No. Group Name Qty Notes
1 Conodonts 13 Pa elements Bispathodus utahensis Sandberg and Gutschick All conodonts identified by A.G. Harris
2 Conodonts 1 subadult Pa element Gnathodus typicus Cooper
3 Conodonts 5 bar fragments "Hindeodella" segaformis Bischoff s.f.
4 Conodonts 12 Pa elements Mestognathus praebeckmanni Sandberg, Orchard, and von Bitter
5 Conodonts 5 Pa elements Polygnathus communis communis Branson and Mehl
6 Conodonts 2 subadult Pa elements Pseudopolygnathus sp. indet.
7 Conodonts 2 Pa element fragments Geniculatus claviger Hass
8 Conodonts 1 Pa element Synclydognathus geminus (Hinde)
9 Conodonts Unassigned elements: 9 Pb (4 morphotypes), 6 M (2 morphotypes), 2 Sb, and 7 Sc (6 morphotypes)
10 Conodonts 66 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 (middle Osagean)
Formation: Lisburne Group
CAI:Min: 2.5 - Max: 3
Comment:Age: Sc. anchoralis-Do. latus Zone (middle Osagean). Mestognathus praebecmanni is a rare conodont. It occurs in another sample from aturbidite within deepwater facies of the Lisburne Group (Akmalik Chert of the Picnic Creek allochthon) in the central Howard Pass quadrangle collected by I.L. Tailleur and described by Dumoulin and others (1993, table 1 and fig. 7K-M).
REFERENCE: Dumoulin, J.A., Harris, A.G., and Schmidt, J.M., 1993, Deepwater lithofacies and conodont faunas of the Lisburne Group, west-central Brooks Range, Alaska, in Dusel-Bacon, Cynthia, and Till, A.B., eds., Geologic studies in Alaska by the U.S. Geological Survey, 1992: U.S. Geological Survey Bulletin 2068, p. 12-30.
Mixed biofacies; probable slope or deeper water depositional environment with admixture from the shallowest-water mestognathid biofacies. Turbidite!!!
CAI = 2.5-3

6.6 kg of rock processed (1540 g of +20 mesh and 249 g 20-140 mesh insoluble residue).
Heavy-mineral concentrate: chiefly phosphatized and pyritized composite grains including a pyritized ostracode steinkern.

Occurrence(s)
No. Group Name Qty Notes
1 Conodonts 13 Pa elements Bispathodus utahensis Sandberg and Gutschick
2 Conodonts 1 subadult Pa element Gnathodus typicus Cooper
3 Conodonts 5 bar fragments "Hindeodella" segaformis Bischoff s.f.
4 Conodonts 12 Pa element Mestognathus praebeckmanni Sandberg, Orchard, and von Bitter
5 Conodonts 5 Pa elements Polygnathus communis communis Branson and Mehl
6 Conodonts 2 subadult Pa elements Pseudopolygnathus sp.
7 Conodonts 2 Pa element fragments Geniculatus claviger Hass
8 Conodonts 1 Pa element Synclydognathus geminus (Hinde)
9 Conodonts UNASSIGNED ELEMENTS: 9 Pb (4 morphotypes), 6 M (2 morphotypes), 2 Sb and 7 Sc (6 morphotypes)
10 Conodonts 60 indet. bar, blade, and platform fragments