Prepared by the
INSTITUTE OF POLAR STUDIES, OHIO STATE UNIVERSITY
under the auspices of the
NATIONAL SCIENCE FOUNDATION

U.S. ANTARCTIC RESEARCH PROGRAM
PLUNKET POINT QUADRANGLE
ANTARCTIC GEOLOGIC MAP A-4

DEPARTMENT OF THE INTERIOR
UNITED STATES GEOLOGICAL SURVEY

Ucien \
Pro Gsatet
Wy spur

\ |

| i
[Davis si faks)
\ BirBeooTM IE

7

172°

Crevasses ~

Hayman

Jk
2
Nunataks g

Qbi
Larkman
Nunatak

CORRELATION OF MAP UNITS

Qs
Qbl

a)
[eae]

Disconformity

QUATERNARY

IT
mae QUATERNARY

AND TERTIARY

Jk

JURASSIC AND
TRIASSIC

TRIASSIC

PERMIAN

Ferrar
} Group | JURASSIC
Victoria |
Group
Beacon

Taylor
Group

Angular unconformity - Kukri erosion surface

Disconformity

=
, DEVONIAN

} CAMBRIAN

DESCRIPTION OF MAP UNITS

SCREE — May also include solifluction deposits, weathered bedrock, and other
surficial deposits

BEARDMORE LOW MORAINE SYSTEM ~— Supraglacial debris up to 20 cm
thick overlying bot active and stagnant ice adjacent to the active ice. The
debris is characterized by angular to subrounded clasts of Beacon sediments
and angular clasts of Ferrar Dolerite

GLACIAL DEPOSITS, UNDIVIDED — Includes undivided Qbl, QTbm and QTbh,
and deposits derived from “‘local ice” expansion (the platform south of Meyer
Desert). On elevated flat surfaces may include weathered bedrock

BEARDMORE MIDDLE MORAINE SYSTEM — Supraglacial debris deposited by
an ice cover more extensive than that which deposited Qbl. The entire deposit
is ice-cemented below 0.5 to 1.5 m depths. The debris is characterized by
clasts of cavernously weathered and disintegrated Beacon sediments, and of
slightly rounded fine-grained Ferrar Dolerite and disintegrated coarse-grained
Ferrar Dolerite. The weathered pebbles and boulders form a lag concentrate
on the surface and overlie silt to sand size particles that are intermixed with
fresher clasts of similar lithologies. Series of continuous boulder ridges (most
notable in Meyer Desert) outline the recessional positions of former ice
termini

BEARDMORE HIGH MORAINE SYSTEM — Supraglacial debris deposited by an
ice cover more extensive than that which deposited QTbm. The entire deposit
is ice-cemented below 1 to 2 m depths. The debris is characterized by clasts of
rounded to cavernously weathered fine- to medium-grained Ferrar Dolerite
and a few clasts of Beacon sediments and coarse-grained Ferrar Dolerite. Below
5-10 cm clasts of Beacon sediments and coarse-grained Ferrar Dolerite in-
crease in abundance and all lithologies exhibit weathering characteristics simi-
lar to Qbl. The upper limit of the deposit can often be differentiated, as on
Otway Massif, by faint ridges and/or erratics

BEARDMORE HIGH AND/OR MIDDLE MORAINE SYSTEM, UNDIVIDED

SIRIUS FORMATION — Grayish-green semi-lithified till and stratified lenses.
The stratified lenses contain sorted and unsorted layers of clasts ranging from
gravel to silt size. The sediments occur as 1-2 m thick (Mt. Black and Otway
Massif) deposits of till or as a basal till overlain by intermixed till and strati-
fied lenses with a maximum measured thickness of 85 m (Meyer Desert). Stri-
ated and faceted clasts up to boulder size occur in the basal till and all local
bedrock lithologies are represented. Where the contact is exposed the basal
till overlies unweathered surfaces and slopes of Ferrar Dolerite or Fremouw
Formation

Disconformity

KIRKPATRICK BASALT — Tholeiitic flows and ponded lavas from 2 to at least
200 m thick. Includes sparse, thin acidic tuff beds and lacustrine deposits
with conchostracans. Many of the thicker lavas have zones of medium-grained
diabase. Amygdules of quartz, chalcedony, calcite and zeolites, principally
heulandite and stilbite, in basal and upper contact zones of lavas. Locally up-
per surfaces have weathering profiles, and at Johnston Heights one is a paleo-
soil. A few lavas enclose tree stumps and wood fragments. K/Ar ages from Mt.
Bumstead of 161+3 m.y., Mt. Cecily of 171+7 m.y. and Mt. Spohn of 1728
m.y. Thickness 500+ m

FERRAR DOLERITE — Tholeiitic diabase sills intruded into the Beacon Super-
group and possibly along the Kukri erosion surface separating the Taylor
Group and underlying rocks; rare dikes: one extensive intrusive mass in the
Supporters Range. Measured sills as thick as 150 m; thicker sills observed.
Large rafts of sedimentary strata “floating” in diabase may have an apparent
structural dip as at Graphite Peak. Flat areas of diabase may include weathered
bedrock

PREBBLE FORMATION -— Light-brown, greenish-brown or reddish-brown mas-
sive poorly sorted lahar debris, pyroclastic breccia, tuff and minor tuffaceous
sandstone, all containing acidic volcanic debris and zeolite. Sparse tuff beds
with accretionary lapilli. Lahar debris locally contains boulders as much as 60
cm across of diabase, basalt, tuff, sandstone, siltstone, shale and coal. Diabase
boulder in lahar debris has K/Ar age of 17910 m.y. Thickness up to 460 m

FALLA FORMATION — Very light gray quartzose sandstone. Exposed only as
araft of sedimentary strata in diabase on north side of Falkenhof Glacier
and as an isolated outcrop at the base of Mt. Petlock. Thickness 30+ m

FREMOUW FORMATION —

Upper part: Mainly light greenish-gray laumontized volcanic sandstone with
some carbonaceous shale. Stems (Neocalamites?), roots and logs common. A
little coal, Dicroidium. About 400 m thick

Middle part:Greenish-gray mudstone with thin beds of light gray volcanic sand-
stone. A few stems and roots. About 250 m thick

Lower part: Cyclic light reddish-brown quartzose sandstone and greenish-gray
mudstone. Lystrosaurus-zone fauna present at Graphite Peak. About 80 m
thick

BUCKLEY FORMATION ~ Cyclic light-colored crossbedded sandstone, carbon-
aceous shale and high-rank, high-ash coal. Log, stems and glossopterid leaves
common. Sandstone beds normally have erosion surfaces at base and shale frag-

a 172° | ments in lower part. Sandstone is subarkosic to arkosic low in formation but
f ht 2 | =
Nee aa 168 250,000 | volcanic fragments become abundant between 100 and 300 m above base. Vot-
_ “166° SCALE. 1:250, canic sandstone, which commonly is laumontized, dominates upper part. No
a i S ms 35 20 Statute Miles complete sections exposed in this quadrangle. Thickness a minimum of 300 m
— 5 ° 5 10 15 20 25 30 Kilometers 7 Det) ‘and probably 600+'m
om [— a — | 7 ‘ | FAIRCHILD FORMATION — Exposed only northwest of Beardmore Glacier.
36" 0? 9°00! ° 5 10 15 Nautical Miles 1 80°¢88"00" Upper part: interbedded quartz sandstone and micaceous siltstone with carbon-

Base from U.S. Geological Survey, 1963

NORTH

Barrett, P.J., 1969a, Stratigraphy and petrology of the mainly
fluviatile Permian and Triassic Beacon rocks, Beardmore
Glacier area, Antarctica: Ohio State Univ., Inst. Polar Stud-
ies Rept. 34, 132 p.

1969b, Geology of Buckley Island, Antarctica: New Zea-
land Jour. Geology and Geophysics, v. 12, no. 2-3, p. 580-
581.

1970, Paleocurrent analysis of the mainly fluviatile Per-
mian and Triassic Beacon rocks, Beardmore Glacier area,
Antarctica: Jour. Sed. Petrology, v. 40, no. 1, p. 395-411.

[1971], Stratigraphy and paleogeography of the Beacon

Polar Stereographic Projection — Standard Parallel 84°14"
CONTOUR INTERVAL 200 METERS—DATUM IS MEAN SEA LEVEL
Elevations and ice thickness in meters

REFERENCES

Barrett, P.J., Baillier, R.J., and Colbert, E.H., 1968, Triassic
amphibian from Antarctica: Science, v. 161, no. 3840,
p. 460-462.

Barrett, P.J., and Elliot, D.H., 1972, The early Mesozoic vol-
caniclastic Prebble Formation, Beardmore Glacier area, in
Adie, R.J., editor, Antarctic geology and geophysics: Oslo,
Universitetsforlaget, p. 403-409.

Coates, D.A., 1972, Pagoda Formation: Evidence of Permian
glaciation in the central Transantarctic Mountains, in
Adie, R.J., editor, Antarctic geology and geophysics: Oslo,
Universitetsforlaget, p. 359-364.

Elliot, D.H., and Coates, D.A., 1971, Geological investigations
in the Queen Maud Mountains: Antarctic Jour. United
States, v. 6, no. 4, p. 114-118.

Kitching, J.W., Collinson, J.W., Elliot, D.H., and Colbert, E.H.,
1972, Lystrosaurus zone (Triassic) fauna from Antarctica:
Science, v. 175, no. 4021, p. 524-527.

Mayewski, P.A., 1972, Glacial geology near McMurdo Sound
and comparison with the central Transantarctic Moun-
tains: Antarctic Jour. United States, v. 7, no. 4, p. 103-
106.

Oliver, R.L., 1964, Geological observations at Plunket Point,
Beardmore Glacier, Antarctica, in Adie, R.J., editor, Ant-
arctic geology: Proceedings of the First International Sym-
posium on Antarctic Geology, Cape Town, 16-21 Septem-
ber 1963: New York, Interscience, p. 248-258.

Tasch, Paul, 1969, Antarctic paleobiology: new fossil data
and their significance: Antarctic Jour. United States, v. 4,
no. 5, p. 198-199.

[1971], Antarctic and other Gondwana conchostracans

and insects; new data; significance for drift theory: Inter-

nat. Union Geol. Sci., Comm. Stratigraphy, Subcomm.

Gondwana Stratigraphy and Palaeontology, Gondwana

Geology mapped in 1965-66 by D.J. Young and R.J. Ryburn assisted

by A.C. Bibby and A.C. Rayment; in 1967-68 by Ralph J. Baillie,

Peter J. Barrett, David H. Elliot, and David Johnston; in 1969-70 by
Donald A. Coates, David H. Elliot, John H. Mercer and assisted by

Jon S. Powell; in 1970-71 by James W. Collinson, David H. Elliot,

Paul A. Mayewski, Vaughn P. Wendland and assisted by Stephen D. Etter
and John Ruben

(eae
Pm
ees |

Disconformity

THE “st. SHACKLETON
CLOUDMAKER | GHAGIER

aceous siltstone near top. Thickness about 90 m
Lower part: White quartz sandstone with well-developed crossbedding, inter-

bedded with minor carbonaceous shale. Thickness about 170 m

MACKELLAR FORMATION ~ Exposed only northwest of Beardmore Glacier.
Fissile well-bedded mudstone and siltstone with interbedded minor white
sandstone and carbonaceous siltstone. Ripple marks and flow casts present.
Thickness 125 m

PERMIAN STRATA, UNDIVIDED — Shown only on the cross section. May in-
clude the Pagoda, Mackellar, Fairchild, and Buckley Formations, and Ferrar
Dolerite sills. The Pagoda Formation, a unit of tillite, sandstone and shale
which underlies the Mackellar Formation, is not exposed in this quadrangle

ALEXANDRA FORMATION — Exposed only northwest of Beardmore Glacier.
White, medium- to coarse-grained micaceous quartzose sandstone, quartzite,
minor pebbly beds, interbedded micaceous siltstone. Soft sediment folding
associated with thin diamictite. Top of formation at Mt. Bowers has glacial(?)
striae. Thickness about 90 m

Angular unconformity

sium, 2d, South Africa, 1970, Proc. and Papers, ves am
Supergroup in the Transantarctic Mountains, Antarctica: 7 Be eeY Bela see —_—! ai ae SET ETONIES TONERS h & hs
Tatemail Union/Geol, Soll,Gommi Stra igraphy\-Subsornin Elliot, D.H., 1970, Jurassic tholeiites of the central Transantare- p. 589-592. a SHACKLET — Dense, light gray, very fine grained limestone,
snare iy wad Palacoctolosy, Gondwana’ | tic Mountains, Antarctica, in Gilmour, E.H., and Stradling, McGregor, V.R., 1965, Notes on the. geology of the area be- Wade, F.A., Yeats, V.L., Everett, J.R., Greenlee, D.W., ke atte limestone breccia, dark gray well-bedded limestone, and calcareous siltstone in
Gondwana Stratigraphy and Palaeontology, ondvans Dale, editors, Proceedings of the Second Columbia River tween the heads of the Beardmore and Shackleton Glaciers, LaPrade, K.E., and Shenk, J.L., 1965, The geology of the sver-eoree svisi0/s small isolated outcrops south of Mt. Bowers. Light gray limestone contains
Symmposiua, 2d-Souttr Africa. 1970; Exocsiaml Papers, Basalt Sympodium: Cheney, Wash., Eaatern Washington Antarctica: New Zealand Jour. Geology and Geophysics, central Queen Maud Range, Transantarctic Mountains, a An4 _ archeocyathids. Thickness 300+ m
Bi 289-256. State Coll. Press, p. 301-325. v. 8, no. 2, p. 278-291. Antarctica: Texas Tech, Coll. Research Rept. Ser., Antarc- ee oa
1972, Stratigraphy and petrology of the mainly fluvia- tic Ser., no. 65-1, 54 p. svsi-son | svsi-60712 | visting
: tile Permian and Triassic part of the Beacon Supergroup, 1972, Major oxide chemistry of the Kirkpatrick Basalt, Mercer, J.H., 1972, Some observations on the glacial geology Young, D.J., and Ryburn, R.J., 1968, The geology of Buckley ~
Bernt oor Tee Beardmore Glacier area, in Adie, R.J., editor, Antarctic central Transantarctic Mountains, in Adie, R.J., editor, of the Beardmore Glacier area, in Adie, R.J., editor, Ant- and Darwin Nunataks, Beardmore Glacier, Ross Dependen- oY rT Ter =o Coritact = Dashed wh .
: : : - ntact — Dashed where approximately located
SOUTH geology and geophysics: Oslo, Universitetsforlaget, p. 365- Antarctic geology and geophysics: Oslo, Universitets- arctic geology and geophysics: Oslo, Universitetsforlaget, cy, Antarctica: New Zealand Jour. Geology and Geophy- SOUTH
8p Korlaaet, BATS-AIB, P. 427-433. sies, v. 11, no. 4, p. 922-939. = Fault — Dotted where concealed. U, upthrown side; D, downthrown side
Compiled from U.S.N.O.O. chart 1706 S, 1960 Sheet numbering system based on
ISOGONIC LINE DIAGRAM International Map of the World 120 Strike and dip of beds
INDEX TO ADJOINING SHEETS
—-500— Structure contour — Approximately located. Drawn on base of Beacon Super-
, group. Datum is mean sea level. Contour interval 500 meters
METERS METERS ‘ * m
4000 4000 > Base of measured stratigraphic section
Dominion Range z §
3000 a 3 3000
Meyer Desert Fe A
a 2
2000 MILL GLACIER avi ® SNAKESKIN GLACIER QbI.

1000

SEA LEVEL

Thickness of surficial units Qs, Qbl, QTbm, and QThm exaggerated

2000

1000

VERTICAL EXAGGERATION X 2.5

By

SEA LEVEL

INTERIOR—GEOLOGICAL SURVEY, RESTON, VA.—1974

David H. Elliot, Peter J. Barrett, and Paul A. Mayewski

1974

RECONNAISSANCE GEOLOGIC MAP OF THE PLUNKET POINT QUADRANGLE, TRANSANTARCTIC MOUNTAINS, ANTARCTICA

For sale by U.S. Geological Survey, Reston, Va. 22092, price $1.00