70°13' 70°10' 70°08' 70°06' 70°04' 70°02'

42°18'

42°19'

70°13' 70°11' 70°09' 70°07' 70°05' 70°03'

42°14'

42°16'

42°18'

42°19'

42°14'

42°16'

70°11' 70°09' 70°07' 70°05' 70°03'

70°12' 70°10' 70°08' 70°06' 70°04'

42°17'

42°15'

42°13' 42°13'

42°15'

42°17'

70°12'

70°02'

Prepared in cooperation with the

National Oceanic and Atmospheric Administration

U.S. Department of the Interior

U.S. Geological Survey Scientific Investigations Map 3341

Map G

STELLWAGEN BANK NATIONAL MARINE SANCTUARY

STELLWAGEN BANK

N I N E T Y M E T E R B A N K S

NORTH 

NINETY

BANK

SOUTH

NINETY

BANK

EAST

NINETY

BANK

MIDDLE

NINETY

BANK

DESCRIPTION OF MAP UNITS

[Mud content is given as mean weight percent. See table 5 for textural characteristics of 

individual substrates. See Mapping Methods for explanation of topographic contour 

intervals]

Mud content ≤1—Equivalent to substrates A1, A2, and B of Map D

Mud content >1 to 5—Equivalent to substrates D1 and E of Map D

Mud content >5 to 10—Equivalent to substrates F and G1 of Map D

Mud content >10 to 20—Equivalent to substrate D2 of Map D

Mud content >20 to 50—Equivalent to substrate G2 of Map D

Boulder ridges <1 m in height—Equivalent to substrate C of Map D

Boulder ridges ≥1 m in height—Equivalent to substrate C of Map D

Merrimack River

0 20 km

CAPE COD

CAPE

ANN

Plymouth

Provincetown

Gloucester

BOSTON

MAS SACHUSETTS

BAY

GULF

OF

MAINE

71°00'W 70°45'W 70°30'W 70°15'W 70°00'W

Location Map.—Shows quadrangle 6 (highlighted in yellow). Stellwagen Bank 

National Marine Sanctuary boundary is shown as a dashed line. Bathymetric 

contours are labeled in meters.

40

200

100

100

100

100

80

80

80

80

40

80

80

40

100

80 40

40

CAPE COD BAY

8

5

9

10 11 12

4

1 2 3

14 15

16 17 18

13

7

42°45'N

42°30'N

42°15'N

42°00'N

41°45'N

6

RACE POINT CHANNEL

STELLWAGEN

BANK

BASIN STELLWAGEN

JEFFREYS LEDGE

TILLIES BANK

Any use of trade, firm, or product names is for descriptive purposes only and does not imply 

endorsement by the U.S. Government

Digital files available at http://pubs.usgs.gov/sim/3341/

Suggested citation: Valentine, P.C., and Gallea, L.B., 2015, Distribution of substrate mud content, 

map G of Seabed maps showing topography, ruggedness, backscatter intensity, sediment mobility, 

and the distribution of geologic substrates in quadrangle 6 of the Stellwagen Bank National Marine 

Sanctuary region offshore of Boston, Massachusetts: U.S. Geological Survey Scientific 

Investigations Map 3341, scale 1:25,000, http://dx.doi.org/10.3133/sim3341.

ISSN 2329-132X (online)

http://dx.doi.org/10.3133/sim3341

SCALE 1:25 000 

ONE CENTIMETER ON THE MAP REPRESENTS 250 METERS ON THE SEA FLOOR 

1 .5 0 1 2 3 4 KILOMETERS

1 .5 0 1 2 NAUTICAL MILES 

CONTOUR INTERVAL 5 METERS

ADDITIONAL 1-METER CONTOURS INCLUDED TO SHOW BOTTOM ROUGHNESS

DATUM MEAN LOWER LOW WATER

Mercator projection

Geodetic Reference System 1980; North American Datum of 1983

Longitude of central meridian 70°19' W; latitude of true scale 41°39' N

False easting 0 m; false northing 0 m

This map is not intended for navigational purposes.

Map G.—Distribution of Substrate Mud Content

Seabed Maps Showing Topography, Ruggedness, Backscatter Intensity, Sediment Mobility, and the

Distribution of Geologic Substrates in Quadrangle 6 of the Stellwagen Bank National Marine Sanctuary Region

Offshore of Boston, Massachusetts

By

Page C. Valentine and Leslie B. Gallea

2015