DEPARTMENT OF THE INTERIOR U.S. ANTARCTIC RESEARCH PROGRAM

U.S. GEOLOGICAL SURVEY Prepared by the WELCOME MOUNTAIN QUADRANGLE
UNITED STATES GEOLOGICAL SURVEY ANTARCTIC GEOLOGIC MAP A-14

Under the auspices of the
NATIONAL SCIENCE FOUNDATION
From contributions by
BUNDESANSTALT FUR GEOWISSENSCHAFTEN UND ROHSTOFFE

and
U.S. ANTARCTIC RESEARCH PROGRAM
’ 159° 30" 160° 30° Aen
157°30 mie eT 7 aE Tena ; elu 162°00'
72°00! ; oe : ; 72°00! CORRELATION OF MAP UNITS
JURASSIC
JURASSIC AND
TRIASSIC

Angular unconformity (Kukri erosion surface)
ORDOVICIAN AND
CAMBRIAN

CAMBRIAN(?) OR
PROTEROZOIC(?)

tye

DESCRIPTION OF MAP UNITS

pace Kirkpatrick Basalt—Tholeiitic lava flows with thin sedimentary
and pyroclastic interbeds occurring very sparsely.
[ane | Ferrar Dolerite and Section Peak Formation undifferentiated—
Ferrar Dolerite—Sills of tholeiitic diabase separated and under-
lain by thin slivers of sandstone. Typically has columnar joint-
ing. Age is Jurassic.
Section Peak Formation—Medium to coarse-grained, trough-
cross-bedded sandstone, that is feldspathic and contains vol-
ach canic detritus including altered shards. The sandstone overlies
an irregular erosion surface on granite at Mt. Bower and
Roberts Butte, where it is approximately 18 m thick and capped
fi 1s) by diabase. At Johannessen Nunataks, sandstone crops out at
the northern end both above and below a diabase sill approxi-
mately 80 m thick. A Late Triassic age is suggested by micro-
floral fossils.

Granite Harbour Intrusives—Strongly peraluminous syeno- and
monzogranites, both equigranular and porphyritic (K-feldspar
phenocrysts). Tourmaline and garnet are accessory phases in
some plutons. Muscovite is common, though most or all is
probably secondary. The granites generally are texturally
homogenous in pluton interiors, but have complex intrusive
and migmatized margins.

Raha

Pegmatitic and aplitic dikes are common throughout the quad-
‘ : rangle, intruding both Wilson metasediments and Granite Har-
Seung ¢ i bor plutons. The pegmatites are both zoned and unzoned.
tt sic rvs Ten hitban Graphic texture occurs in some. Cavities with euhedral crystals
Name eee are common. Tourmaline, mainly schotl, is ubiquitous; rubellite
: and verdelite occur in a brecciated pegmatite at Mt. Joern.
Beryl and Fe-cordierite occur in pegmatites of Frontier Moun-
tain. Garnet is common.
© eews * Wilson metamorphics-metasediments—Equivalent to Rennick
Group of Gair (1967). Fine-grained, psammitic and pelitic
schists with minor layers and lenses up to several cm thick of
calcsilicate granulite and impure marble. At Mt. Weihaupt
layered quartz-biotite schists contain plagioclase, muscovite,
fibrolite, altered cordierite(?) porphyroblasts, and rare andalu-
site; quartz segregations contain garnet and vesuvianite.
* Indicates localities where pegmatites and aplites intrude Wil-
i son metasediments

EXPLANATION OF MAP SYMBOLS

30'
Contact

———— Fault deduced from change in height of cover rocks
\wwwwwwy Gradational igneous contact

= Strike and dip of bedding
a

SELECTED REFERENCES

Borg, S.G., 1984, Granitoids of northern Victoria Land, Antarctica: Arizona
State University, Tempe, Ph.D. dissertation, 355 p.

Borg, S.G., Stump, Edmund, and Holloway, J.R., 1986, Granitoids of north-
erm Victoria Land, Antarctica: A reconnaissance study of field relations, pe-
trography and geochemistry; in Stump, Edmund, (ed.), Geological Investi-
gations in Northern Victoria Land, Antarctic Research Series, v. 46, Ameri-
can Geophysical Union, p. 115-188.

Borg, S.G., Stump, Edmund, Chappell, B.W., McCullock, M.T., Wyborn,
Doone, Armstrong, R.L., and Holloway, J.R., 1987, Granitoids of northern
Victoria Land, Antarctica: Implications of chemical and isotopic variations to
regional crustal structure and tectonics: American Journal of Science, v. 287,
p. 127-169.

Collinson, J.W., and Kemp, N.R., 1982, Sedimentology of the Takrouna For-
mation, a Permian-Triassic fluvial deposit in northern Victoria Land: Antarc-
tic Journal of the United States, v. 17, p. 15-17.

Collinson, J.W., and Kemp, N.R., 1983, Permian-Triassic sedimentary se-
quence in northern Victoria Land, Antarctica: in Oliver, R.L., James, P.R.,
and Jago, J.B., (eds.), Antarctic Earth Science, Australian Academy of Sci-
ence, Canberra, p. 221-225.

45! Collinson, J.W., Pennington, D.C., and Kemp, N.R., 1986, Stratigraphy and
“ Petrology of Permian and Triassic fluvial deposits in northern Victoria Land,
Antarctica: in Stump, Edmund, (ed.), Geological Investigations in Northern
Victoria Land, Antarctic Research Series, v. 46, American Geophysical
Union, p. 211-242.

Gair, H.S., 1967, The geology from the upper Rennick Glacier to the coast,
northern Victoria Land, Antarctica: New Zealand Journal of Geology and
Geophysics, v. 10, p. 309-344.

Gair, H.S., Sturm, Arnold, Carryer, S.J., and Grindley, G.W., 1969, The geol-
ogy of northern Victoria Land: American Geographical Society, Antarctic
Map Folio Series, 12, Sheet 13.

Grew, E.S., Kleinschmidt, Georg, and Schubert, Wolfgang, 1984, Contrasting
metamorphic belts in north Victoria Land, Antarctica: Geologisches
Jahrbuch, v. B 60, p. 253-263.

Pennington, D.C., and Collinson, J.W., 1984, Sedimentary petrology of Per-
mian and Triassic Beacon sandstones, northern Victoria Land: Antarctic
Journal of the United States, v. 19, p. 10-11.

Department of Geology, Arizona State University, Tempe, Arizona 85287, U.S.A.

Department of Geology and Mineralogy and Institute of Polar Studies, The Ohio State University,
Columbus, Ohio 43210, U.S.A.

Department of Geological Sciences, University of Maine, Orono, Maine 04469, U.S.A.
Department of Geology, University of Melbourne, Parkville, Victoria 3052, Australia
Bundesanstalt fiir Geowissenschaften und Rohstoffe, D-3000 Hannover 51, Federal Republic of

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| 160° 30!
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73°00" 158° * 301 WEROR-SEOLOGCAL SUEY. STOR VA ! 73°00"
157°30' 162°00'
Base from U.S. Geological Survey Manuscript approved for publication,
April 29, 1987

SCALE 1:250 000

10 15 20 25 MILES
COMPILATION DIAGRAM 7 = : } GEOLOGIC MAP COMPILATION INDEX TO ADJOINING SHEETS
5 0 5 10 15 20 25 30 35 KILOMETERS
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Photogrammetric compilation

[||| sapped by US. Anrci Reseach Progam
Isogonic lines compiled from U.S.N.O.0.

Chart 1706 S, 1965 Sheet numbering system based on

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RECONNAISSANCE GEOLOGIC MAP OF THE WELCOME MOUNTAIN QUADRANGLE,
TRANSANTARCTIC MOUNTAINS, ANTARCTICA

Compiled by
Edmund Stump

From contributions by
Scott G. Borg’, James W. Collinson’,
Edward S. Grew’, John R. Holloway’, Michael Sandiford‘,
Norbert W. Roland®, and Edmund Stump’

For sale by U.S, Geological Survey, Map Distibution,
1989 Box 25286, Federal Center, Denver, CO 80225