!

! !

!

!

!

!

!

!

AHc

AHc

AHc

AHc

AHc

AHc

AHc

AHc

AHc

AHc

AHc

AHc

AHc

AHc

AHc

AHc

AHc

AHc

AHc AHc

AHc

AHc

ABb3

ABb3

ABb3

ABb3

ABb3

ABb1

ABb1

ABb1

ABb3

AHc

AHc

ABu

ABb2

AHc

AHc

ABu

ABb1

ABu

ABu

ABu

ABu

ABu

ABu ABu

ABu

ABu

ABu

ABb2

ABb2

ABb2

ABb2

ABb2

ABb2

ABb2

ABb2

ABb2

ABb2

ABb2

ABb2

ABb2

ABu

ABb1

ABu

AHc

AHc

AHc

AHc

AHc

AHc

AHc

ABu AHc

ABu

ABu

AHc

AHc

ABb1

ABu

ABu

ABb1

ABu

HBvi

AHc

ABu

ABu

ABu

ABu

AHc

AHc

AHc

AHc

AHc

HBs

ABu

AHc HBs

AHc

HBs

ABu ABu

ABu

ABu

ABu

ABu

ABu

ABu

ABu

ABu

ABu

ABu

ABu

ABu

ABu

ABu ABu

ABu

ABu

ABu

ABu

ABu

ABu

ABu

AHc ABb3

ABb3

ABb3

ABb3

ABb3

ABb3

ABb3

ABb3

ABb3

ABb3

ABb3

ABb3

ABb3

ABb3

ABb3

ABb3

ABb1

AHc

ABu

AHc

HBs

HBs

HBs

AHc

AHc

AHc

AHc

AHc

HBs

HBs

HBs

HBs

HBs

HBs

HBs

HBs

HBs

ABu

AHc

ABu

ABu

ABu

ABb2

ABb2

ABb2

ABb2

ABb2 HBvi

ABb2

ABb2

ABb2

ABb1

ABb1

ABbc

ABbc

ABbc

ABbc ABbc

ABb1

ABb1

ABb1

ABb1

ABb1

ABb1

ABb1

ABb1

ABb1

ABb1

ABb1

ABb1

ABb1

ABb1

ABb1

ABb1

HBbr

HBbr

HBbr

HBbr

HBbr

HBbr

HBbr

ABb1

ABb1

ABb1

ABb1

ABb1

ABb1

ABb1

ABb1

ABb1 ABb1

AHc

AHc

AHc

AHc

ABb1

HBbr

HBbr

HBbr

ABb1

ABb1

ABb1

HBbr

HBbr

HBbr

HBbr

HBbr

AHc

AHc

HBbr

ABu

ABb2

AHc

HBvi

AHc

AHc

AHc

ABb3

AHc

AHc

ABb1

AHc

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

HBvi

ABbc

ABbc

ABbc

ABbc

ABbc

!

Planum Boreum 3 unit—Forms as many as 6 to 8 layers each 

several meters thick of moderately high or variable albedo 

having knobby margins and diffuse interlayer boundaries; 

moderate surface ice abundance

Planum Boreum 2 unit—Forms low-albedo material; layers 

evident in places; low ice abundance. As much as several tens 

of meters thick

Planum Boreum 1 unit—Finely layered, high-albedo in 

upper part and moderate-albedo in lower part; moderate ice 

content. Locally exceeds 1000 m in thickness. Includes bright 

horizontal reflectors and local discontinuities in SHARAD 

radar data

Planum Boreum cavi unit—Dark and light even to irregular 

layers typically meters thick; local cross bedding; overall low 

water ice abundance. Locally reaches a couple hundred meters 

in thickness

Planum Boreum rupēs unit—Evenly layered; >20 layers 

total exposed, each ~10 to 100 m thick; likely high ice content. 

Diffuse and moderately reflective in MARSIS and SHARAD 

data. Locally 1000 m thick along Rupes Tenuis

Covers most of Planum Boreum, including some pole-facing trough walls, and 

scattered outlier mesas of Olympia, Abalos, and Tenuis Mensae. Mostly thinly 

mantled by bright residual ice. Local unconformities occur within unit. Locally 

cut by grabens and pits along low ridges and scarps above western Olympia 

Rupēs

Covers parts of floors and slopes of Chasma Boreale, Olympia Cavi and Rupēs 

and nearby troughs, and margins of Gemina Lingula east of Chasma Boreale. 

Variably hummocky and bumpy surface. Locally includes possible cut-and-fill 

structures

Forms much of upper Planum Boreum and scattered patches in the surrounding 

plains; exposed mainly in southward-facing scarps; unit may exceed 1500 m 

thickness near north pole. Exposures typically include sequences of dozens to 

hundreds of even layers mostly meters thick (interrupted by a few prominent, 

thicker layers); lower sequences polygonally fractured. Local internal unconformities commonly with dark surfaces, particularly in lower, outer parts of Planum 

Boreum. Marked by arcuate patterns of troughs and undulations and dissected 

by Chasma Boreale. Sparsely cratered by impacts tens to a few hundred meters 

in diameter. Displays cross-hatched fracturing within 10 to 12 kilometers of 

43-km-diameter Udzha crater

Lines lower, steep walls of Olympia, Boreum, and Tenuis Cavi, northern 

Olympia Planum, Chasma Boreale, and depression in western Abalos Mensa. 

Light-toned layers typically form prominent ledges marked by polygonal 

fractures spaced meters apart, whereas dark layers less fractured and more 

friable and disaggregated into dark soils, ripples, and dunes

Forms much of the basal section of the main lobe of Planum Boreum, particularly along Rupes Tenuis and lower parts of Olympia Rupēs and Cavi; also 

forms low (~300 m thick) Hyperborea Lingula plateau covering the base of 

Chasma Boreale; likely forms plateau underlying Escorial crater ejecta and 

perhaps material of Abalos Colles. Layer margins commonly form knobs and 

rounded, concave-upward plates. Superposed by several multi-kilometerdiameter craters including Boola and Crotone

Late Amazonian nearly pure water ice with small dust concentration except for 

thin surficial dust lags; likely undergoing thermokarst degradation and eolian 

erosion, particularly on unit margins

Late Amazonian dusty to sandy eolian mantle derived largely from Planum 

Boreum cavi and rupēs units

Middle to Late Amazonian atmospherically precipitated and transported ice and 

dust perhaps deposited during episode of overall lower obliquity and originating 

from lower latitude sources; alternating layers may result from cyclic climatic 

and depositional conditions. Glacial deformation not apparent but brittle 

contraction cracks and possible subsurface faults beneath troughs evident. 

Exposed surfaces may be partly covered by dust mantle

Middle to Late Amazonian poorly indurated sandy weathered basalt fines 

deposited by wind, interbedded with ice-rich layers. Sandy material may 

originate from erosion of Planum Boreum rupēs and Scandia units. Occurrence 

may be spotty, within former wind-sheltered hollows carved within Planum 

Boreum rupēs unit. Perhaps generated during a mostly high-obliquity epoch

Early to Late Hesperian, ice-laden, fine-grained deeply eroded but presently 

indurated deposits. Generally undeformed except for polygonal graben network 

that cuts lower section of unit making up Hyperborea Lingula and Hyperboreus 

Labyrinthus

Undae unit—Includes dunes typically tens to hundreds of 

meters across and tens to more than 100 m high, as well as 

rippled and bumpy mantle material commonly between and 

surrounding dunes. Low albedo in defrosted, summertime 

images and bright (warm) in THEMIS daytime infrared 

images; low ice abundance

Vastitas Borealis interior unit—Vast, moderately cratered 

plains-forming deposits

Scandia region unit—Forms singular and chained subcircular 

to irregular complexes of domical hills of Scandia Tholi and 

Cavi tens to a few hundred kilometers across and tens to 

hundreds of meters in relief

Crater material—Forms crater rims and bowls and surrounding blankets commonly elevated meters to tens of meters 

above subjacent units. Outcrops >15 km across mapped

Forms broad, irregular patches encircling much of Planum Boreum; locally 

confined within subtle topographic traps and craters; more pronounced dune 

fields include Olympia Undae and other areas within and south of Chasma 

Boreale (Hyperborae and Abalos Undae) that appear to be made up of individual 

and chains of barchan dune forms. High abundance of Type 2 TES spectral type; 

OMEGA data indicate overall signature of hydration plus gypsum concentrated 

on upper parts of Olympia Undae

Typically marked by scattered higher albedo bumps ~1 to several kilometers 

across. South of Chasma Boreale and around western Scandia Tholi and Cavi in 

some of the lowest elevation plains marked by a polygonal network of shallow 

trough segments tens of meters deep, a few hundred to 2000-m wide and several 

kilometers long. Also contains scattered circular depressions up to tens of 

kilometers in diameter. Unit largely obscured by recent thin mantle deposits

Larger hill complexes have interior and surrounding depressions (Scandia Cavi) 

tens to hundreds of meters deep and a few narrow sinuous ridges a couple 

kilometers wide and tens of kilometers long. Many tholi bounded by shallow 

moats within surrounding, underlying Vastitas Borealis interior unit. Wrinkle 

ridges in adjacent Vastitas Borealis units disappear in Scandia region unit. Unit 

largely obscured by recent thin mantle deposits

Blankets vary considerably and are missing in some cases and include thin ones 

with ramparts and extensive, smooth, thick ones (of so-called ‘pedestal craters’). 

See table 4 for descriptions of crater types distinguished by geomorphologic and 

geologic characteristics

Late Amazonian ergs of wind-blown, weathered basaltic silt and sand, locally 

rich in gypsum and other hydrated minerals. Originates mostly from local 

erosion of Planum Boreum cavi unit and some Planum Boreum 2 unit, particularly from west- to south-facing cavi-wall outcrops and buried surfaces in 

eastern Olympia Planum. Dunes largely inactive at present; likely active during 

higher obliquity episodes, particularly > 4–5 million years ago

Early to Late Hesperian sediments of outflow channels that dissect highlands 

thousands of kilometers south of map area. Pervasively altered and deformed 

during Late Hesperian by compaction, mud volcanism, and other periglacial 

processes involving subsurface volatiles. Scattered bumps may be degraded, 

infilled crater forms

Early to Late Hesperian sedimentary and cryoclastic volcanism may have 

formed much of unit and attendant collapse structures, perhaps instigated by 

Alba Patera magmatism. Unit may be deeply eroded

Late Hesperian to Amazonian ejecta resulting from larger impacts

Unit Unit Name and Definition

symbol

Additional characteristics* Interpretation

DESCRIPTION OF MAP UNITS

PLANUM BOREUM UNITS

CIRCUMPOLAR PLAINS UNITS

CRATER MATERIAL

*Mineral and ice compositional data are from CRISM, OMEGA, and TES data and reflect surface compositions generally indicative in high albedo 

regions of ice and dust and in low albedo regions of basaltic and perhaps andesitic or altered basaltic lithologies that may include zeolites, silica glass, and 

minor amounts of clay minerals; eastern Olympia Undae also include gypsum signatures (Bandfield, 2002; Wyatt and others, 2004; Langevin and others, 

2005; Tanaka and others, 2008; Horgan and others, 2009).

EXPLANATION OF MAP SYMBOLS

Contact—Dashed where approximate; dotted where gradational

Graben

Unconformity

Residual ice

ABb3

ABb2

ABb1

ABbc

HBbr

ABu

HBvi

HBs

AHc

PLANUM

BOREUM

UNITS

CIRCUMPOLAR

PLAINS UNITS

NON-SEDIMENTARY

POLAR GEOLOGIC EVENTS

CRATER

MATERIAL

Erosion of unit perhaps during higher obliquity

Erosion of units results in dune fields during possible higher obliquity

Accumulation of lithic particles and ice cementation result in unit

Troughs and scarps eroded into units ABbc and ABb1; Jojutla impact

Polar ice deposited in meter-thick layers; erosion in lower sequences on outer 

parts of Planum Boreum result in unconformities (interior black lines)

Accumulation of sand and interbeds of ice result in unit ABbc

Mantles episodically cover plains; when impacted and later removed they form 

pedestal craters

Polygonal troughs form in plains and lower part of unit HBbr forming Hyperborea Lingula

Erosion of unit HBbr and related plains material forms Rupes Tenuis, Chasma 

Boreale marginal scarps, and pedestal craters on the unit; Boola, Escorial, 

Crotone impacts

Scandia region resurfacing: mud diapirism and volcanism and gypsum 

generation instigated by Alba Patera magmatism forms unit HBs and HBb

Waning of catastrophic outflow channel activity that results in upper deposits of 

unit HBvi

; compaction and local volatile release from unit HBvi

residual

ice

episodic

mantle

material

AGE EPOCH BOREALIS PROVINCE

Late

Middle

Early

undae unit

Scandia

region unit

Vastitas

Borealis

interior unit

AMAZONIAN

HESPERIAN

CORRELATION OF MAP UNITS

ABb3

ABb2

ABb1

ABbc

HBbr HBvi

ABu

HBs

AHc

–6443 m –2262 m

Figure 1. Shaded-relief view of Mars Global Surveyor (MGS) Mars Orbiter Laser Altimeter (MOLA) digital 

elevation model (DEM) of the map region (230 m/pixel; also version at 115 m/pixel used in mapping), which 

forms the primary map base. Artificial illumination is from upper left. Geographic features are from the 

IAU/USGS Gazetteer of Planetary Nomenclature (http://planetarynames.wr.usgs.gov/).

10–2

10–3

10–4

10–5

10–6

10–7

100 101

Crater diameter, km

Cumulative plot (psuedo-log binning) 

Cumulative crater frequency, km–2

10–2

10–3

10–4

10–5

10–6

10–7

Cumulative crater frequency, km–2

102

A

10–4

10–5

10–6

10–7

100 101

Crater diameter, km

Crater diameter, km

Incremental plot (root-2 binning) 

Production-Function Fit

102

C

101 100 101 102 103

D

100 10–3

10–1

10–2

10–3

10–4

10–5

100 101

Crater diameter, km

R-plot (root-2 binning) 

Cumulative crater frequency, km–2

Cumulative crater frequency, km–2

102

B

Figure 2 (right). Mars Reconnaissance Orbiter (MRD) Context Camera (CTX) image mosaic (constructed 

at 6.2 m/pixel; version provided here is 24 m/pixel due to size) of the Planum Boreum region of Mars in 

Polar Stereographic projection. The mosaic includes ~1400 images from the testing, primary, and extended 

mission phases. The Planum Boreum set has ~99% coverage with images from orbits T02 thru B03, but 

excludes orbits P13 thru P19 because of obscuration due to presence of the polar hood. The circumpolar 

plains tile set has ~70% coverage and includes images from all orbits with those from P13 thru P19 used as 

background images. The mosaic is not controlled, but it is sufficiently georeferenced to the MOLA 

topographic model such that in most places the mosaic’s spatial accuracy is adequate for mapping at 

1:2,000,000 scale. Images are not tone matched; however, the residual ice layer on Planum Boreum 

provides fairly consistent pixel values on which to stretch the individual images and the tiles, resulting in a 

useful, but not photometrically balanced, product.

Figure 3 (right). Mars Odyssey (ODY) mission Thermal Emission Imaging System (THEMIS) visual-range 

image mosaics of the Planum Boreum region in Polar Stereographic projection (courtesy of P.R. Christensen, 

Arizona State University). The mosaics are at half the spatial resolution of the original images, which were 

obtained at full (18 m/pixel) and half instrument resolution. A, Summertime images at 36 m/pixel north of lat 

80° N. B, Summertime images at 72 m/pixel north of lat 75° N. C, Springtime images at 36 m/pixel north of 

lat 75° N. D, Springtime images at 72 m/pixel north of lat 75° N.

Figure 8. Graphs showing crater size-frequency 

distributions of impact craters in the map region 

for the Planum Boreum rupēs unit (red data), 

Vastitas Borealis interior unit (green data), and 

Scandia region unit (blue data). A, Cumulative 

density; B, R-plot density; C, incremental density 

(binned in square root of the diameter increments); 

and D, production-function fit. Cumulative and 

incremental plots are compared to model 

isochrones developed by Hartmann and Neukum 

(2001). See Crater Analyst Techniques Working 

Group (1979) and Michael and Neukum (2007) for 

descriptions of plot details.

A

C

B

D

Mars Orbiter Camera (MOC) footprints

High Resolution Imaging Science

 Equipment (HiRISE) footprints

Figure 4. Plot showing locations of Mars Global Surveyor (MOC) (>3 m/pixel) and Mars Reconnaissance Orbiter (HiRISE) (25 cm/pixel) images in the map region obtained during all seasons and 

released as of May 2009, on a background showing the topography in shaded relief based on the 

MOLA DEM.

Figure 6. Map of unconformities (red lines) and grabens (black lines with balls in box) in Planum 

Boreum 1 unit and Planum Boreum 3. Background shows the topography in shaded relief based on 

the MOLA DEM as well as unit contacts.

Figure 5. Composite mosaic of three color images acquired by the Mars Reconnaissance Orbiter 

Mars Color Imager (MARCI) on October 16th of 2006 during Martian northern summer, solar 

longitude, Ls = 121°. The MARCI frames are blended with a MOLA shaded relief (~230 m/pix) to 

enhance topographic features, which are somewhat muted by atmospheric haze in the color images. 

The image shows the region north of lat 72o N. at ~1000 m/pixel. The color is derived from three 

spectral bands acquired at 425 nm, 550 nm, and 600 nm. We mapped the high-albedo residual ice 

using this mosaic. Additional color units shown in Tanaka and others (2008) include beige-colored 

dust, low-albedo basaltic sand, and mixtures of low- and moderate-albedo materials with sparse 

residual ice.

Figure 7. Plot showing the distribution of impact craters > 2 km in diameter in the map region (see 

table 4 regarding morphologic and other characteristics). These include craters used in crater 

statistics (table 2 and fig. 8).

Superposed on Planum Boreum rupēs unit (20)

Superposed on Scandia region unit (41)

Superposed on Vastitas Borealis interior unit (259)

Buried or embayed craters (39)

Circular depressions (37)

4 Ga

3 Ga

3 Ga

1 Ga

1 Ga

100 Ma

100 Ma

10 Ma

10 Ma

4 Ga

Equilibrium

3.7 Ga

3.7 Ga

3.62 Ga

3.59 Ga

+0.04

–0.07

+0.06

–0.10

3.45 Ga +0.03

–0.04

O L Y M P I A P L A N U M

V A S T I T A S B O R E A L I S

S C

O

P

U L I

B

O

R

E

A

L

E S

Udzha

Puyo

Jojutla

Boola

Escorial

Inuvik

Dokka

G E M I N I S C O P U L I

Tenuis

Cavus

Boreum

Cavus

Hyperborei

Cavi

Olympia Cavi

Olympia Cavi

Olympia Cavi

Hyperborea

Lingula

Gemina Lingula

Hyperboreae Undae

PLANUM

Olympia Undae

Olympia Undae

Olympia

Mensae

Tenuis Mensa

Abalos Undae

V A S T I T A S

B

O

R

E

A

L I S

Scandia

Cavi

Siton

Undae

Crotone

BOREUM

CHASMA BOREALE

Hyperboreae

Undae

Hyperboreus

Labyrinthus

Scandia

Cavi

Scandia

Cavi

Sevel

Olympia Rupēs

Olympia

Rupē

O

s

lympia Rupēs

Abalos

Scopuli

Abalos

Mensa

180o

0o

270o E 90o E

75o N

80o N

85o N

85o N

80o N

75o N

180o

0o

270o E 90o E

75o N

80o N

85o N

85o N

80o N

75o N

180o

0o

270o E 90o E

75o N

80o N

85o N

85o N

80o N

75o N

180o

0o

270o E 90o E

75o N

80o N

85o N

85o N

80o N

75o N

180o

0o

270o E 90o E

75o N

80o N

85o N

85o N

80o N

75o N

180o

0o

270o E 90o E

75o N

80o N

85o N

85o N

80o N

75o N

0°

180° E

270° E

270° E

270° E

270° E

90° E

90° E

90° E

90° E

85° N

80° N

0°

180° E

85° N

80° N

75° N

85° N

80° N

75° N

0°

180° E

0°

180° E

85° N

80° N

75° N

O

L

Y

M P I A P L A N

U

M

V A S T I T A S

B

O

R

E

A

L

I

S

S

C

O

P

U

L I

B

O

R

E

A

L

E

S

G

E

M

I

N

I

S

C

O

P

U

L

I

Udzha

Puyo

Jojutla

Boola

Escorial

Inuvik

Dokka

G

E

M

I

N

I

S C

O

P

U

L

I

Tenuis

Cavus

Boreum

Cavus

Hyperborei

Cavi

O l y m p i a C a v i

O l y m p i a

C a v i

O l y m p i a C a v i

Hyperborea

Lingula

Gemina Lingula

H y p e r b o r e a e U n d a e

PLANUM

O

l y

m

p

i

a

U n

d a

e

O l

y m

p i

a

U

n

d

a

e

Olympia Mensae

Tenuis

Mensa

Abalos Undae

V

A

S T I T A S

B O

R

E

A

L

I

S

Scandia

Cavi

Siton

Undae

Crotone

BOREUM

CHASMA BOREALE

Hyperboreae

Undae

Hyperboreus

Labyrinthus

Scandia

Cavi

Abalos Mensa

Sevel

O l y m p i a

R u p ē s

O l y m p i a

R u p ē s

Abalos

Colles

Abalos

Scopuli

Abalos

Scopuli

O l y m p i a

R u p ē s

R

u

p

e

s

T e

n

u

i s

R

u

p

e

s

T e n u i s

180o

0o

30o E

60o E

90o E

120o E

150o E

210o E

240o E

270o E

300o E

330o E

75o N

80o N

85o N

85o N

80o N

75o N

U.S. Department of the Interior

U.S. Geological Survey

Prepared for the

National Aeronautics and Space Administration

Scientific Investigations Map 3177

Atlas of Mars: North Polar Region

Pamphlet accompanies map

Printed on recycled paper

Geologic Map of the North Polar Region of Mars

By

Kenneth L. Tanaka and Corey M. Fortezzo

2012

Prepared on behalf of the Planetary Geology and Geophysics Program, 

Solar System Exploration Division, Office of Space Science, National 

Aeronautics and Space Administration

Edited by Theresa Iki

Cartography by Darlene A. Ryan

Manuscript approved for publication August 29, 2011

Descriptions of nomenclature used on map are listed at 

http://planetarynames.wr.usgs.gov/

SCALE 1:2 000 000 (1 mm = 2.00 km) AT LAT 90° N.

SCALE 1:2 034 656 (1 mm = 2.03 km) AT LAT 75° N.

POLAR STEREOGRAPHIC PROJECTION

Planetocentric latitude and east longitude coordinate system

Any use of trade, product, or firm names in this publication is for descriptive purposes only 

and does not imply endorsement by the U.S. Government

For sale by U.S. Geological Survey, Information Services, Box 25286, Federal Center, 

Denver, CO 80225, 1–888–ASK–USGS

Digital files available at http://pubs.usgs.gov/sim/3177

Suggested citation: Tanaka, K.L., and Fortezzo, C.M., 2012, Geologic map of the North Polar 

Region of Mars: U.S. Geological Survey Scientific Investigations Map 3177, scale 

1:2,000,000 (http://pubs.usgs.gov/sim/3177/).

200 100 80 60 40 20 0 20 40 60 80 100 200 KILOMETERS

90°

75°

90°

75°

80°

85°

80°

85°