DEPARTMENT OF

THE INTERIOR

UNITED STATES GEOLOGICAL SURVEY

45!

|
|

84°00'

15'

Crevasses

Crevasses

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Crevasses

245!
cd 60°00"

Base from U.S. Geological Survey, 1964

PREPARED IN COOPERATION WITH THE

NATIONAL SCIENCE FOUNDATION

54°

53°

‘

lies Rock
187

/Crevalsses

om;

)

i /

Ke
~~" Crevasses

= a 83°00"
cor

52°30’
EXPLANATION

CAMBRIAN PALEOZOIC CAMBRIAN(?)

Sedimentary rocks

Granite of Median Snowfield

li

Diabase intrusions

PRECAMBRIAN

GEOPHYSICAL INVESTIGATIONS

MAP GP-889 (SHEET 1 OF 2)

70" 30° 75 oF

TO
PERMIAN

2

‘ah

WEDDELL SEA

Pensacola Mts.

Patuxent Formation

Sedimentary and volcanic rocks }

152

SCALE 1:250 000

20 Statute Miles

20

30 Kilometers

Polar Stereographic Projection—Standard Parallel 80°14’
CONTOUR INTERVAL 200 METERS—DATUM IS MEAN SEA LEVEL

15 Nautical Miles

15!
Contact

lc

Fault
Showing relative horizontal movement. U,
upthrown side; D, downthrown side

Q|

—50

-60 +12

GRAVITY CONTOURS — Dashed where approximate-
ly located. Hachured contours enclose area of low
gravity. Contour interval 10 milligals. Data are not
terrain corrected. Contours drawn assuming all
terrain corrections for stations on rock would be
positive. Contours extending to map edge based on
data in adjacent areas

4

GRAVITY STATION — Showing simple Bouguer gravity
value in milligals. Bouguer gravity values on ice sheet
were based on reflection-seismic thickness measure-
ments of the ice. Bouguer correction made using
densities of 0.9 and 2.67 g/cm’ for ice and rock
respectively. On grounded ice the Bouguer correction
was made by subtracting the effect of slabs of ice and
rock of combined thickness equal to the elevation
using appropriate densities. If the ice-rock contact
is below sea level an additional correction was made
by adding the effect of slab of 2.67-0.9 = 1.77 g/cm?
of a thickness equal to ice thickness below sea level

Dufek Gabbro

JURASSIC

‘Disconformity

Siltstone and shale
with coalbeds

Gale Mudstone (tillite)

METERS.
45’ 40005
Dover Sandstone (quartzite)

‘Disconformity
3000 Heiser Sandstone

Elbow Formation

Elliott Sandstone
Brown Ridge
Konglomerate
Unconformity
jens Formation
Gambacorta Formation
Nelson Limestone
+—~Unconformity

2000 |

LOWER TO UPPER PALEOZOIC

Neptune Group

1000 ~

Cambrian

;

Patuxent Formation

UPPER PRECAMBRIAN

PENSACOLA MOUNTAINS COMPOSITE

STRATIGRAPHIC SECTION
From Schmidt and Ford (1969)

COMPILATION DIAGRAM

60°00" 52°30"
|33°00" caeot|

84°00" 84°00"
60°00" 52°30"

Photogrammetric compilation

Isogonic lines compiled from U.S.N.O 0
Chart 1706 S, 1965

30"

52200020

Gravity surveyed in 1965-66.

Geology generalized and simplified
from D. L. Schmidt (unpubished map)

Aircraft support by U.S. Army

SIMPLE BOUGUER GRAVITY AND GENERALIZED GEOLOGIC MAP OF THE SCHMIDT HILLS QUADRANGLE

By

John C. Behrendt, William Rambo, and Laurent Meister

1973

AND PART OF THE GAMBACORTA PEAK QUADRANGLE, ANTARCTICA

° 500 KILOMETERS
Lea.

INDEX MAP OF THE PENSACOLA MOUNTAINS REGION
SHOWING SNOW SURFACE ELEVATION. CONTOUR IN-
TERVAL 200 METERS; 100 METER CONTOURS SHOWN
ON ICE SHELF. SHADED AREA IS EXPOSED BEDROCK

30° 60° 52°30'
75700" 67°30' 30’ Asie.
81°00" 81°09,
82" A 82°
CORDINER
PEAKS
83° 83°

THOMAS
HILLS:

85°90" 45°88"00"
INDEX OF THE PENSACOLA MOUNTAINS REGION
SHOWING MAP AREA (SHADED), RONNE ICE

SHELF, AND PUBLISHED TOPOGRAPHIC QUAD—
RANGLES

LOCATION DIAGRAM
30° WEST O° EAST 30°

120° 120°

150° WEST 180° EAST 150°

TOPOGRAPHIC MAP LEGEND

Ice area _ ice-free area

Contour lines
(definite)
(approximate)
(conjectural)

Cliff or escarpment

Steep slope

Small hillocks.

intersected control stations

Photogrammetric elevations

Ice thickness

Astro control station

Survey control stations
Traverse route with spot height
Moraine

Glacier

Crevasses

Coastline under ice (definite; indefinite)

Ice shelf
see TTT ayy AETTTITY

Icebergs ro PP!

Fast or bay ice

50°00"
84°00"

85°

For sale by U.S. Geological Survey, price $1.00 per set
Explanatory pamphlet accompanies this map