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that contains the Upper Devonian Rant Pork Shale and
Kanayut Comlomerate, end the l'dis-ppim and
Pennsylvanian Kuna Formatlan. Recognition of the
Brooks Ranga allochthon in the Baird Mountains is
important because all the known significant mineral
occurrences in the De Long Mountains are in this
allochthon (Mayfield and others, 1979).
The Klvivik Creek drainage is in the northwest
comer of the Balrd Mountains quadrangle and lles
within the Noatak National Wilderness and Preserve.
Attention was fnitldly drawn to this area because It
contains several red3tained creeks slmilar to those in
the Bed Dcg area. lnvestigatiohs in 1078 revealed a
few high geochemical values, and gamma-ray intensi-
ties as high as 24 times the average value (Curtis and
others, 1979). Pollowup strearnsedlment geochemical
sampling in 1979 and 1981 showed that several draln-
ages in one area have anomaIously high elemental con-
centrations (stippling, fig. 8). Copper, lead, and zinc
were measured by both atomic absorption and semi-
quantitative ernissjonspectrographic methods, end
silver by emission gectrography only. Copper values
range as high as 320 parts per mllllon @prn), lead
values as high L% 360 pprn, zinc values as high as 1,200
ppm, and silver values as high as 20 ppm. 'be absolute
abundance3 of, and the ratios between, copper, lead,
and zinc are nearly identical to those in samples from
streams draining the Lik and Red Dog deposits (Net-
aieck and others, 1980). Nearly all the samples with
the higher values are from streams that drain the Kuna
Formation. No sulfides were found in pLace during
reconnaissance mapping, other than some flnely dis-
I seminated pyrite. On the basis of its geologic and
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geochemical similarities to rocks h the Red Dog dis-
trict, the Brooks Range allochthon in the Agashashok
anticlinorlum should be considered highly prospective
for zlnc-Iead-sllver deposits of the Red Dog type.
REFERENCES CITED
Curtis, S. M., ROssiter, Richard, Ellersieck, I. P., May-
field, C. P., and Tailleur, I. L, 1979, Gamma-ray
values h the Misheguk Mountain region and h
parts of Barrow, Teshekpuk, and Harrison 8ay
quadrangles, Alaska, Johnson, K. Ra, and
Williams, J. R., eds., The United States Oeologi-
cal Survey in Alaska! Accomplishments during
1978: U.S. Geological Survey Circular 804-8, p.
B14.
Ellersieck, Inyo, Mayfield, C. P., Tailleu, I. L., and
Curtls, S. M., 1979, Thrust sequences in the
M isheguk Mountain quadrangle, Brooks Range,
Alaska, 5 Johnson, K. M., and WUams, J. R,
eds., The United State GeoIogicd Survey in
Alaska! Accornpllshments during 1978: U.S.
Geological Survey Circular 804-B, p. B&B9.
Ellersieck, Inyo, Curtis, S. Ma, Gruzensky, A. L., May-
field, C. F., and MUeur, I. L., 1980, Copper,
lead, and zinc in stream-sediment samples from
the De Long Mountains quadragle, Alaska: U.S.
Geological Survey Open-File Report 80-795,
scale 1:63,360, 3 sheets.
Jones, A h , 1982, Red Dog ore deposit said spectaau-
lar: Northern Miner, v. 67, no. 51, p. 1.
Mayfield, C. F., Curtis, S. M., Ellersieck, hyo., and
Tallleur, I. L., 1979, Reconnaissance geology of
the Ginny Creek Zn-Pb-Ag and Nirniuktuk barite
deposits, northwestern Brooks Range, Alaska:
U.S. GeologlcJ h e y Open-Pile Report 79-
1092, 20 p.
Mull, C. G., Taillwr, I. L., Mayfield, C. F., EUewieck,
Inyo, and Cur&, S. M., 1982, New late Paleozoic
and early Mesozoic stratigraphic unlts, central
and western Brooks Range, Alaska: American
Association of Petroleum Geologists Wetin, v.
66, no. 3, p. 348-362.
By J. 'lbomss I)utro, Jr, All3son R PaLme, John K
Jr., and William P. Roe&
The recalcitrant rocks of Doonerak (cover photograph~
area I, fig. 5) yield thek secrets grudghgly.
For many years, we have probed and sampled this
anctent antlclinorium, part of the autochthonous
basement of the central Brwks Range, Alaska (Dutro
and others, 19761, in whlch folded and faulted volcdc
rocks, metarnorphased fine-grained clastic rocks, and
marble are intruded by dikes and sUls of two ages (470
m.y. and 350 rn.y.1. Upper Devonian (Prasnfan) strata
Ue unconformably on parts of the mtlclinortum, and
Lower CarbonLferous beds truncate all older structures
with angular unconformlty (Orosgd and Reiser, 1971).
During the Late Jurasslc and Cretaceous building of
the ancient Brooks Range, all these rocks were intruded,
folded, faulted, thrust northward, and uplifted
to initlate Barly Cretaceous coarse clastic sedl m entation
on the Arctic slope.
What Is the age of the old metamorphic terrane
of Doonerak? Because it is intruded by dikes as old as
470 m.y., we opined ln 1976 that .the sedimentary rocks
might be Cambrian or Ordovician. This was not anuninformed
guess because similar an ticlinoria in the
northeastern autochthonous Brooks Range contain Pussiltferous
Lower and Upper Cambrlan and Middle
Ordovlaian rocks In analogous terranes that also include
volcanlc rocks (Reiser and others, 1971, 1980).
Of course, It may be pospible that only Precambrian
strata are present near Doonerak.
In previous summers, we spent many hours lo&ing
for graptoUtes in the fine-grained mks, but to no
avail. Several samples were processed for possible
microfa~sils, again with no results.
At last, during the 1981 summer field seesan, we
found megafossils in sandy Limestone that ia intimately
associated with the black fine-gralned elastic sequence.
h the hills south of Wolf Creek, nem the
north margin of the anticlinorlum (fig. 9), several fsohted
gray marble bodies are surrounded by black siltstone
and 8rgilllte and intruded by greenstone dikes.
Just above one of these marble bodies, in brownweathering
sandy limestone, we found many trilobite
fragments and a iew brachiopads. According to A. R.
Palmer, these trilobites include Kootenia cf. 5
anabarensls Lermontova, "Parehmania" &L&
Chernysheva, and Pagetla sp. and are most Ukely earw
Middle Cambrian, corrdative with the Arngan Stage of
Siberia. The brachlopods are Niswla sp., a common
Middle Cambrian genus. A samplefrom the same beds
was prcreeSed for microfossils by J. & Repetski, Jr.,