Sample: |
Sample No. 92AD33-61.5 -- USGS No. 32435-PC
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Locality: |
Field No. 92AD33-61.5
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Description: |
Howard Pass C-3. Measured section extends from 68o 30'40"/157o 31'00" (top) to 68o 30'32"/157o 31'34" (base). Sample from 50-cm-thick bed of dolostone immediately underlying chert that has crinoidal grainstone texture. Thin section is dolomite-crystal mosaic containing a few relict crinoid ossicles and having 50-10 percent chiefly intercrystalline porosity. Collected 61.5 m below top of measured section. (description from Dover et al., 2004, p. 42 (Table 1)). [Howard Pass C-3. 68°30'43", 157°31.00". 50 cm-thick bed of dolostone immediately underlying chert with crinoidal grainstone texture. Collected from 61.7 m below top of measured section. 92AD32, 33, 49A, 47 from platformal facies of Lisburne Group at Mt. Bupto, ~1-2 miles east of headwaters of Bushy Creek and ~4 miles southwest of Rim Butte along west side of eastern half of Mount Bupto, western Brooks Range. 92AD32A collected from "Black Lisburne" facies, overlying (structurally and stratigraphically(?) rest of the samples (92AD33, 49, 47). Age of similar rocks at Ivotuk Hills is Chesterian (85ASi14-18). 92AD33-0.2 to -120 from 1240 m and 1100 m elevation of continuously exposed chert and dolostone along trend with measured section of Gus Armstong (<0.25 mile due north), who suggested an age of Meramecian (based on silicified colonial corals and forams) for the upper 100 m (at least) of section (see Armstrong, AAPG Bulletin, v. 54, p. 251+, 1970); N part NE1/4 sec. 9, T. 11 S., R. 24 W, lat. 68°30'43" to 68°30'37", long. 157°31'00" to 20", Howard Pass C-3 quadrangle. (description from Harris E&R report dated March 17, 1995)] |
Location: |
Alaska Quadrangle: Howard Pass C-3 Township&Range: 11 S. 24 W. Section: 9 Lat.: 68o30'40 " Long.: 157o31'00 " |
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Reference
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Title: |
Report on Referred Fossils
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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: | Osagean-Meramecian (middle Osagean - Meramecian) |
Formation: | Lisburne Group |
CAI: | Min: 1.5 |
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Comment: | Age: middle Osagean-Meramecian (based on constraints from under- and overlying collections. Biofacies: Postmortem transport within or from the bispathodid-kladognathid biofacies; open-marine depositional environment. CAI = 1.5 7.7 kg of rock processed (160 g +20 mesh and 307 g 20-200 mesh insoluble residue). Heavy-mineral concentrate: chiefly dolomite rhombs. |
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