Atlantic Continental Shelf and Slope 

of the United States 

Sand-Size Fraction of Bottom Sediments, 

New Jersey to Nova Scotia 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 529-K 

Atlantic Continental Shelf and 

Slope of the United StatesSand-Size Fraction of Bottom 

Sediments, New Jersey to 

Nova Scotia 

By JAMES V. A. TRUMBULL 

GEOLOGICAL SURVEY PROFESSIONAL PAPER 529-K 

Distribution of the sand-size fraction of bottom 

sediments on the continental margin 

from New Jersey to Nova Scotia) their 

source) and local modification processes 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON 1972 
UNITED STATES DEPARTMENT OF THE INTERIOR 

ROGERS C. B. MORTON, Secretary 

GEOLOGICAL SURVEY 

V. E. McKelvey, Director 

Library of Congress catalog-card No. 72-600176 

For sale by the Superintendent of Documents, U.S. Government Printing Office 

Washington, D.C. 20402- Price 55 cents (paper cover) 

Stock Number 2401-2185 
CONTENTS 

Abstract -----------------------------------------

Introduction -------------------------------------

Description of area ---------------------------

Hydrology ------------------------------------

Geologic setting -------------------------------

Previous work ------------------------ ______ _ 

Methods -------------------------------------- Acknowledgments ____________________________ _ 

Areal distribution of components __________________ _ 

Detrital components _________________________ _ 

Rock fragments _______ _ ________________ _ 

Dark minerals -----------------------------

Mica ___ ----------------------------------- Quartz and feldspar _____________________ _ 

Glauconite ___ ---------------------------

Biogenic components __________________________ _ 

Foraminifera __________________________ _ 

Shell fragments _______________________ _ 

Other biogenic components ________________ _ 

Authigenic components _______________________ _ 

GlauconUe -------------------------------

Pyrite __ ---------------------------------- Limonite ______________________________ _ 

Characteristics of quartz grains _________________ _ 

Roundness -----------------------------------

Sphericity -----------------------------------

Frosting -------------------------------------

Page 

K1 

2 

2 

4 

4 

4 

6 

8 

8 

8 

8 

10 

12 

13 

15 

18 

18 

20 

20 

23 

23 

24 

24 

25 

25 

25 

25 

Iron-stained grains --------------------------- Highly rounded and frosted grains ____________ _ 

Sediment types -----------------------------------

Modern detrital sediments --------------------

Protected inshore areas -------------------

~earshore beach-sand zone ----------------

Western Gulf of Maine -------------------- Basins on the continental shelf ____________ _ 

Silt deposit south of Martha's Vineyard ___ _ 

Continental slope -------------------------

Continental rise --------------------------

Relict sediments ------------------------------

~onglaciated shelf south of ~ew England __ _ 

Glaciated nearshore shelf south of 

~ew England --------------------------

Georges Bank, ~ antucket Shoals, Great 

South Channel -------------------------

Floor of the Gulf of Maine ----------------

Zones of winnowed sand ------------------

Continental shelf near ~ova Scotia _______ _ 

~ ortheast Channel and tips 

of adjacnt banks ----------------------

Organic sediments ----------------------------

Authigenic, residual, and rafted components _ 

Geologic history ------------------------------------

The present regime -------------------------------

References ---------------------------------------

ILLUSTRATIONS 

FIGURE 1. Map of the continental margin off the northeastern coast of the United States, 

Page 

K25 

27 

28 

28 

28 

29 

29 

29 

29 

36 

37 

38 

38 

38 

38 

39 

40 

40 

40 

41 

41 

41 

42 

42 

Page 

showing sample localities ______ -------------------------------------------------------------- K2 

2-7. Contour maps showing percentage of2. Sand-sized material in original sample ----------------------------------------------------- 7 

3. Rock fragments in sand-size fraction ------------------------------------------------------- 9 

4. Dark minerals in sand-size fraction ------------------------------------------------------- 11 

5. Mica in sand-size fraction ---------------------------------------------------------------- 13 

6. Quartz and feldspar in sand-size fraction --------------------------------------------------- 14 

7. All types of glauconite in sand-size fraction ---------------------------------------------·-- 16 

8. Map showing inshore limit of glauconite in surface sediment, and inferred present-day extent of sedimentary rocks in the Gulf of Maine ---------------------------------------------------------- 17 

9. Contour map showing percentage of Foraminifera in sand-size fraction ------------------------------ 19 

10. Contour map showing percentage of shell fragments in sand-size fraction -------------------------- 21 

11. Map showing distribution of minor biogenic components and pyrite in the sand-size fraction __________ 22 

12. Map showing distribution of glauconitic internal molds of Foraminifera --------------------------- 23 

13. Contour maps showing variation of characteristics of quartz grains -------------------------------- 26 

14. Map and profiles showing topography and composition of sand-size fraction on selected traverses _______ 30 

15. Graphs showing average composition and size distribution of surface sediment in individual areas _____ 34 

16. Map showing areas of major sediment types and of Holocene and relict sediments ------------------ 36 

III 

ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATESSAND-SIZE FRACTION OF BOTTOM SEDIMENTS. 

NEW JERSEY TO NOV A SCOTIA 1 

By JAMES v. A. TRUMBULL 

ABSTRACT 

Examination of the sand-size fraction of surface sediments 

divides the continental shelf off the Northeastern United 

States into three distinctive areas. These are the glaciated 

Gulf of Maine and Nova Scotia shelf, the shallow high-energy 

Georges Bank-Nantucket Shoals area, and the more normal 

continental shelf south of New England and Long Island and 

east of New Jersey. 

Surface sediments of the Gulf of Maine are predominantly 

of relict glacial origin and have been reworked little since 

deposition. They are poorly sorted, and their sand-size fraction is mostly composed of quartz and feldspar grains, rock 

fragments, and dark minerals. Fine-grained micaceous sediments are being deposited in local basins off the eastern 

Massachusetts and New Hampshire coasts and in the protected waters and nearshore basins of the coast of Maine. 

Larger topographic basins nearer the center of the Gulf of 

Maine have flat accretionary floors on which clay, some silt, 

sand-size mica flakes, and foraminiferan tests and other 

organic debris are now settling. Basins in areas of high 

currents in the eastern and northeastern Gulf of Maine are 

mostly covered with relict sand and some gravel, as is 

Northeast Channel, the only deep-water hydraulic entrance 

to the gulf. Well-sorted fine quartzose sands inshore of 

Georges Bank and inshore of the shallow shelf near Nova 

Scotia were winnowed from those areas during the postglacial 

transgression and are also now relict. 

Sediments of most of the Nova Scotia shelf are generally 

similar to the poorly sorted glacially derived rock debris 

of most of the Gulf of Maine, though the Nova Scotia shelf 

also contains topographic basins floored with fine-grained 

sediment. 

Georges Bank is more than 50 km from land, but large 

areas of it are less th\.n 60 m deep. Over most of the shallower 

parts of the bank little but clean quartz sand and minor 

amounts of detrital glauconite have survived the constant 

wave turbulence and current transport. The perimeter of the 

bank is marked by slight concentrations of detrital glauconite eroded from the coastal plain strata underlying the 

bank. The sands of Nantucket Shoals in general share the 

characteristics and the environment of Georges Bank. 

1 Contribution 2416 of the Woods Hole Oceanographic Institution, based 

on work done under a program conducted by the U.S. Geological Survey 

and the Woods Hole Oceanographic Institution and financed by the U.S. 

Geological Survey. 

Sand covers most of the continental shelf south of New 

England and Long Island and east of northern New Jersey. 

Most of the sand is well sorted and moderately well rounded. 

The sand was deposited primarily as glacial and fluvial outwash during glacial-stage lowering of sea level and was 

slightly reworked during the following transgression. It is 

therefore relict in origin. Silt on the middle and outer shelf 

south of Martha's Vineyard apparently postdates the transgression. River-derived gravel blankets a large area on the 

inner half of the shelf off northern New Jersey. Holocene 

detrital sand occurs in a narrow zone off the sandy beaches 

of New Jersey and Long Island. Narragansett Bay, Long 

Island Sound, and other protected inshore areas are floored 

primarily with Holocene micaceous silty sediment. 

Over all the continental shelf the primary components of 

the sand-size fraction are quartz and feldspar, with a strong 

admixture of rock fragments and dark minerals in the 

glaciated Gulf of Maine and Nova Scotian shelf, and with 

a variable admixture of foraminiferan tests and shell fragments. Locally, very high concentrations of glauconite are 

found in the bight between New Jersey and Long Island 

and south of Long Island. 

Except in the vicinity of Georges Bank, glauconite appears 

to be forming along the entire length of the outer continental 

shelf and upper slope. Other authigenic minerals include only 

minor amounts of pyrite and possibly limonite. 

Compared with the shelf sediments, the sand-size fraction 

of upper continental slope sediments is enriched in glauconite, 

mica, and dark minerals and is impoverished in rock fragments. The slope sediments off Georges Bank, Northeast 

Channel, and the Nova Scotia shelf contain more quartz, 

feldspar, and rock fragments and less mica and biogenic 

material than the slope sediments south of New England. The 

percentage of foraminiferan tests in the sand fraction increases at the rate of 2.5 percent per 100-meter depth increase 

on the slope south of New England, but the rate is 1.5 percent 

off Georges Bank and northeastward. 

Most of the sediments on the upper continental rise between 

Hudson Canyon and Georges Bank contain less than 2 percent sand, and only about 10 percent of the sand is detrital, 

the remainder being mostly foraminiferan tests. In certain 

areas of the rise, however, 10-25 percent of the sediment is 

sand, and 53-82 percent of the sand fraction is detrital in 

origin. Those areas probably indicate mass transport from 

the continental slope. Much poorly sorted glacially derived 

Kl 
K2 ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

sediment characteristic of the floor of the Gulf of Maine is 

present on the continental slope outside northeast Channel. 

Normal hemipelagic sedimentation has not yet deeply buried 

these anomalous sediments of the slope and rise. 

INTRODUCTION 

The conventional methods of studying unconsolidated marine sediments-size, heavy-mineral, X-ray, 

chemical, and paleontological analysis-have recently been supplemented by an improved technique 

of displaying the results of binocular microscope 

examination of the washed sand-size fraction. Originated by Shepard and ~oore (1954) in a study of 

Gulf of ~exico sediments, the technique is a direct 

and effective method of characterizing and differ0 50 

0 50 

tiating sediments and their environments. In the 

work herein reported, the technique has been applied to the surficial sediments off the Northeastern 

United States to aid in revealing the geologic and 

oceanographic history of the area and to determine 

the present-day processes and the distribution of 

sediment types. 

DESCRIPTION OF AREA 

This report covers the continental shelf from 

northern New Jersey to Nova Scotia and the adjacent continental slope and upper continental rise 

(fig. 1). 

The area of continental shelf under consideration 

is about 230,000 km2, or about two-thirds of the 

100 150 STATUTE MILES 

100 150 KILOMETERS 

L_____L_ _ _L__ _ _J 

DEPTHS IN METERS 

FIGURE 1.-Map of the continental margin off the northeastern coast of the United 

States, showing sample localities. 
SAND-SIZE FRACTION OF BOTTOM SEDIMENTS, NEW JERSEY TO NOVA SCOTIA K3 

area of the entire continental shelf along the east 

coast of the United States. Maximum width of the 

continental shelf in the mapped area is about 400 

km. The continental slope and continental rise here 

investigated total, respectively, 33,000 and 84,000 

km2

• The total area under consideration, 347,000 

km2

, is about twice that of the six New England 

States. 

All available soundings in the mapped area have 

been compiled by Uchupi (1965a). Because of its 

detailed contouring, Uchupi's map should be at 

hand when this report is read. 

The mapped area has two dist,inct shoreline types. 

The shoreline of Nova Scotia ·and most of Maine 

is rocky, highly irregular in outline, and generally 

lacking in sandy beaches. It is bordered on the seaward side by a zone of irregular rocky bottom 25-

50 km wide. The contrasting shoreline type is a 

straight or gently curved sandy beach, bordered by 

an offshore zone of generally smooth sandy bottom. 

The latter shoreline type is represented by the outer 

end of Cape Cod, the shores of Nantucket, the south 

shore of Long Island, and the New Jersey coast. 

The shoreline from southern Maine south to Cape 

Cod and thence westward through Long Island Sound 

is a mixture of the two types : Rocky headlands and 

points alternate with generally smooth sandy 

beaches. Johnson ( 1925) presented details of coastal 

morphology in this area. 

The coastal area includes numerous bodies of protected water in restricted communication with the 

sea. The Maine coastline is so irregular that much 

of its length is occupied by generally small protected water bodies. The largest are Penobscot Bay, 

into which the Penobscot River discharges,and Casco 

Bay. From Casco Bay south to Cape Cod the coast 

is predominantly open, but from Cape Cod to New 

Jersey much of the coastline is sheltered. Major 

protected water bodies there are Cape Cod Bay 

within the hook of Cape Cod, Nantucket and Vineyard Sounds, Buzzards Bay, Narragansett Bay, Block 

Island and Long Island Sounds, and Raritan Bay 

in northern New Jersey. The bottom sediments of 

those protected areas are strongly affected by restricted communication with the sea. 

The outer Nova Scotia continental shelf resembles other glaciated shelves of the world (Holtedahl, 1958) in having basins on its inner part and 

banks on its outer part. For example, La Have Bank 

on the outer half of the shelf has a minimum depth 

of 77 m, but the Roseway Basin on the inner part 

of the shelf has a maximum depth of 185 m. Similarly, Browns Bank, south of Nova Scotia, has a 

minimum depth of 33 m, but between it and Nova 

Scotia is a passage more than 120 m deep. 

Although the southern and southwestern parts of 

the Gulf of Maine are relatively smooth-floored, 

the northwestern, central and northeastern sides 

have numerous ridges, pinnacles, and gullies. 

Within the gulf are no fewer than 21 topographic 

basins separated by ridges, swells, and banks. Basin 

depths range from 64 to 377 m (Uchupi, 1965b). 

Georges Bank, seaward of the Gulf of Maine, is 

delineated by the 100-meter depth contour, and 

about half of it is shallower than 60 m. Between 

Georges Bank and Browns Bank is Northeast Channel, the only deep-water entrance to the Gulf of 

Maine. Sill depth is between 220 and 240 m. At the 

southwestern end of Georges Bank is Great South 

Channel, a shallow and weakly delineated secondary 

hydraulic entrance to the Gulf of Maine. Its sill 

depth is between 60 and 80 m. Between Great South 

Channel and Nantucket Island is Nantucket Shoals. 

Its depths are generally less than 40 m, and in 

general character it is similar to Georges Bank. The 

shallower parts of both Georges Bank and Nantucket Shoals contain large sand ridges (Jordan, 

1962; Stewart and Jordan, 1964). 

The continental shelf from Nantucket Shoals 

southwestward to the limit of the area is of the 

conventional type in that depths generally increase 

continuously to seaward, and the 100-meter depth 

contour is near the outer edge. The inner and central shelf between Long Island and New Jersey is 

cut by Hudson Channel, and the outer shelf is 

deeply incised by Hudson Canyon. 

Water depths at the outer edge of the continental 

shelf in the mapped area are in the range 130-160 m. 

The gradient of the continental slope is from 1 o 

to 6 o. The transition at the base of the slope to the 

more gently inclined continental rise is at depths 

close to 2,000 m, except at the northeastern end of 

the mapped area where it is at almost 1,000 m. 

Relief on the continental slope thus ranges from 

about 800 to about 1,800 m. Between Northeast 

Channel and the New Jersey coast the continental 

slope is incised by 10 major named submarine canyons that indent the shelf edge and by numerous 

gullies. 

The outer boundary of the area studied was determined by the limit of sampling rather than by a 

natural boundary. The water depth at the outer edge 

of the continental rise, where it meets the Sohm 

Abyssal Plain, is about 5,000 m, whereas the deepest 
K4 ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNIT'ED STATES 

sample used in this study is from a depth of 4,560 

m. In general, sample coverage extends to a depth of 

about 2,000 m in the area north from Bear Seamount 

and, in a more open pattern, to a depth of about 

4,000 m in the area to the southwest of Bear Seamount. 

HYDROLOGY 

The tidal range at the shoreline is about 1-2 min 

most of the area, but it increases to about 4 m at 

the entrance to the Bay of Fundy. Because of that 

high range, vertical or horizontal restrictions on 

water flow cause high-velocity bottom currents that 

can be effective geologic agents. Nantucket Shoals, 

Georges Bank, Browns Bank, and the shallow area 

between Browns Bank and Nova Scotia have highvelocity bottom currents because they constrict the 

flow of water into and out of the Gulf of Maine; 

these areas show the effects of sediment winnowing 

and transport. Surface current velocities exceed 1 

knot over most of those areas. On the shallower 

parts of Georges Bank they average 2 knots at the 

tidal maximum (U.S. Coast and Geodetic Survey, 

1967), though far higher velocities have been recorded. The velocity of bottom currents is largely 

unknown. One measurement from the bottom of 

Northeast Channel showed 0.6 knot at the peak of 

the tidal cycle. The constriction at the eastern end 

of Long Island Sound causes tidal currents that have 

largely removed fine-grained sediment and left a 

bouldery bottom. Surface currents there exceed 5 

knots (U.S. Coast and Geodetic Survey, 1947). 

The 10 largest rivers discharging in the area have 

average discharges at the mouth that range from 

640 m3 per second (22,790 cfs) to 46 m3 per second 

(1,625 cfs) (C. D. Bue, unpub. compilation). In 

decreasing order of average discharge, they are the 

Hudson, Connecticut, Kennebec-Androscoggin, Penobscot, Merrimack, Saco, Housatonic, St. Croix, 

Thames, and Raritan Rivers. The St. John River, 

which discharges into the Bay of Fundy 40 km 

beyond the mapped area, has an average discharge 

of more than 700 m3 per second (25,000 cfs), more 

than any river within the area. 

GEOLOGIC SETTING 

The land adjacent to the mapped area has a crystalline basement of igneous and metamorphic rocks 

mostly of Paleozoic age. The basement is exposed at 

the surface (or is covered by a thin deposit of 

glacial material) throughout most of New England 

and Nova Scotia, and it probably underlies nearly 

the entire adjacent continental shelf. Sedimentary 

and intercalated basaltic volcanic rocks of T'riassic 

age are downfaulted into the basement on both sides 

of the Bay of Fundy and beneath its floor and extend 

southwestward a considerable distance beneath the 

Gulf of Maine (Tagg and Uchupi, 1966; fig. 8 of 

present report) . Another such downfaulted block 

of rocks of Triassic age reaches the coast in central 

Connecticut. 

A seaward-thickening prism of predominantly 

clastic sedimentary rocks of Cretaceous and Tertiary 

age overlies the crystalline basement. It is subaerially exposed in northern New Jersey and on Martha's 

Vineyard and is known to underlie Long Island, 

parts of Cape Cod, the continental shelf south of 

them, Georges Bank, and parts of the Gulf of Maine 

(Schlee and Cheetham, 1967) and the continental 

s_helf seaward of Nova Scotia (Marlowe, 1965). This 

sedimentary prism crops out on the continental slope 

at least from Georges Bank southwestward. 

Continental glaciers crossed much of the area 

from a generally northward direction during the 

Pleistocene. The probable limit of glacial advance 

is marked by terminal moraines on Long Island, 

Block Island, Martha's Vineyard, and Nantucket, 

and is thought to be at or near the northwestern 

flank of Georges Bank (fig. 1). All of the Gulf of 

Maine and Northeast Channel and probably most, 

if not all, of the Nova Scotian continentaLshelf were 

glaciated (King, 1967). A generally thin deposit 

of till and other glacial detritus was deposited over 

the glaciated area, and outwash material was carried beyond the limit of glacial ice. During glacial 

maxima, eustatic sealevel lowering on the order of 

115 m (King, 1967) to 165 m (Ewing and others, 

1963) exposed much of the continental shelf. 

PREVIOUS WORK 

On becoming Superintendent of the U.S. Coast 

Survey in 1844, A. D. Bache directed that bottom 

samples brought up by the sounding lead in hydrographic surveying be preserved (Pourtales, 1872, p. 

220). The first systematic collection of such samples 

was made by his brother, G. M. Bache, in the section 

of coast between Rhode Island and New Jersey, at 

least as early as 1844 (U.S. Coast Survey, 1848, p. 

25). The samples were examined microscopically 

and described by Bailey (1851), who expressed surprise at the large number of Foraminifera in the 

samples and noted the presence of fossils of Paleozoic age in gravels offshore from New Jersey. 

Supplementing Bailey's work with his own observations, L. F. Pourtales of the U.S. Coast Survey 

published (1870, 1872) a bottom-sediment map of 
SAND-SIZE FRACTION OF BOTTOM SEDIMENTS, NEW JERSEY TO NOVA SCOTIA K5 

the east coast of the United States. The map was 

accompanied by a descriptive text. Bailey's was the 

first published work on marine geology on the east 

coast, and Pourtales' was the first bottom-sediment 

map. Pourtales recognized the area of fine-grained 

sediments on the midshelf south of New England 

and knew that glauconite was forming at the present 

time but that the high concentration of glauconite 

just off New York City was derived from older 

rocks. 

Systematic dredging for scientific purposes, as 

distinguished from the collection of samples adhering to armed sounding leads, was begun by the U.S. 

Coast Survey shortly after the Civil War. The first 

such dredging on the east coast north of the latitude of Delaware Bay was done in 1880 on the third 

cruise of the Coast Survey Steamer Blake, vnder 

the direction of Alexander Agassiz (Agassiz, 1881). 

Descriptions of the samples were published by John 

Murray (1885) and Agassiz (1888). During 1883-

87 the steamer Albatross of the U.S. Fish Commission also did considerable bottom dredging, especially along the seaward side of Georges Bank 

(Townsend, 1901). 

The presence of fossiliferous rocks of Tertiary 

age on Georges Bank was established by A. E. 

Verrill (1878). After study of the U.S. Fish Commission's collection of rocks gathered from Georges 

Bank and other banks by Gloucester fishermen (Upham, 1894), Verrill (1878, p. 324), correctly concluded that "these fragments have been detached 

from a very extensive submerged Teritiary formation, at least several hundred miles in length, extending along the outer banks from off Newfoundland 

nearly to Cape Cod, and perhaps constituting, in 

large part, the solid foundation of those remarkable 

submarine elevations." Dall ( 1925) later restudied 

the material. Verrill wrote extensively on the 

topography and geology of the continental shelf and 

upper slope. His work has recently been reviewed 

by Schopf ( 1968). 

Johnson and Stolfus (1924) demonstrated that 

the Georges Bank cuesta is both topographically 

and geologically analogous to Long Island and onshore New Jersey. Burbank (1929) studied the 

particle-size distribution and the composition of 

the light and heavy mineral suites in 170 samples 

from the Gulf of Maine and the Bay of Fundy. 

Trowbridge and Shepard (1932) analyzed numerous 

nearshore bottom samples from the area between 

Boston and Cape Cod; seaward of an inshore zone 

of sand they found a zone of rocky bottom, beyond 

472-199 0- 72 - 2 

which particle size decreased regularly to silt and 

clay in nearshore basins. Hough ( 1932) commented 

that the rocky bottom was probably a lag concentrate 

of till, and Stetson and Schalk ( 1935) considered it 

a concentrate of a fluvial-glacial deposit. By use of 

sediment pans, Stetson and Schalk found that sand 

from the nearshore area was in transport across 

the zone of rocky bottom in times of heavy storms. 

Sediment pans were also used by Raymond and 

Stetson (1931; Stetson, 1938, p. 30) south of Martha's Vineyard, where poorly sorted material of 10~-t 

median diameter was in transport past a well-sorted 

sand bottom of 560~-t median diameter. 

In studying the origin of Georges Bank, Shepard, 

Trefethen, and Cohee (1934) considered that glaciers 

extended on to the bank top and (in agreement with 

present views) that the sediment of much of the 

floor of the Gulf of Maine "was not derived through 

aqueous sedimentation, but is composed of glacial 

deposits, possibly somewhat modified by present 

marine conditions" (p. 297). 

Henry C. Stetson of Harvard University and the 

Woods Hole Oceanographic Institution was a leading 

investigator of continental margin geology. In his 

view, the shelf sediments are slowly becoming adjusted to present sea level. The midshelf silt and 

clay area south of New England, for instance, he 

took to be an area of present-day sedimentation 

slowly covering the sand bottom inherited from the 

Pleistocene (Stetson, 1938, 1939). Highly rounded 

quartz grains in a zone off the southern New England 

coast he believed to be the result of wind action on 

dunes exposed during Pleistocene sea level lowering 

(Stetson, 1934). 

Stetson also did much dredging in east-coast 

submarine canyons during the years 1934-40. This 

work established the presence of sedimentary rocks 

of Late Cretaceous, Eocene, Miocene, and younger 

Tertiary age beneath the outer continental shelf and 

upper continental slope (Stetson, 1936, 1949; 

Stephenson, 1936; Bassler, 1936; Cushman, 1936). 

Current velocities in Gilbert and Lydonia Canyons 

and on the nearby shelf were measured in 1936, 

and Stetson (1937; Colton, 1964, p. 5) concluded 

that because the shelf and canyon velocities were 

similar, the currents were not the cause of canyon 

cutting. 

Alexander (1934), after examining heavy minerals in Stetson's shelf samples, thought deposition 

was now going on over most of the shelf, an idea 

corrected by Shepard and Cohee (1936). After 

examining 700 samples collected by the Coast and 

Geodetic Survey between Delaware Bay and Martha's 
K6 ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

Vineyard, Shepard and Cohee concluded that the 

shelf sediments are largely relict from previous 

conditions and are partly a lag concentrate. 

Cushman ( 1939) and Northrop and Heezen 

(1951) reported sediment of Eocene age on the 

continental slope south of Rhode Island at depths 

of 880 and 1,000 m. Northrop (1951) divided the 

shelf south of Martha~s Vineyard into zones on the 

basis of changes observed in bottom photographs 

and short cores. McMaster has studied the particlesize distribution and environment of deposition 

(1960) and the heavy minerals (1962) of Narragansett Bay, and Garrison and McMaster ( 1966) and 

McMaster and Garrison (1966) have made similar 

studies of an extensive area on the continental shelf 

off Rhode Island. Data on the particle-size distribution, composition, and bulk properties of 359 cores 

from the continental shelf off New York City are 

to be found in the library of the U.S. Naval Oceanographic Office (Cornell University, 1953, Final harbor report, New York, v. 4 A-F). Wigley (1961) 

studied bottom samples from Georges Bank and 

Great South Channel as part of Bureau of Commercial Fisheries studies of relations between bottom 

materials and benthic organisms. Atlases that include generalized bottom-sediment charts of the 

east coast of the United States have been published 

by the German Navy (Oberkommando der Kreigsmarine, 1943) and the U.S. Navy (U.S. Naval 

Oceanog. Office, 1965). 

The sediments of Buzzards Bay and Cape Cod 

Bay were described by Hough (1940, 1942) in considerable detail, with primary emphasis on the 

particle-size distribution. Twenty years later Moore 

(1963) restudied the bottom sediments of Buzzards 

Bay, emphasizing minor- and trace-element composition and comparisons between the sediments there 

and the lithology of sedimentary rocks. 

Sanders has studied relations between the fauna 

and the particle-size distribution of bottom sediments of part of Long Island Sound (1956) and of 

Buzzards Bay (1958). McCrone (1966a) and McCrone, Ellis and Charmatz (1961) have described 

the sediments of Long Island Sound. McCrone 

(1966b) has discussed those of the Hudson River 

estuary. Foraminifera of the waters between New 

Jersey and Nova Scotia have been studied by Cushman (1944), Parker (1948, 1952a, b), Phleger 

(1952), Todd and Low (1961), and others. 

Beach sands between New Jersey and Nova Scotia 

have been studied by McCarthy (1931, New Jersey 

and Long Island); Colony (1932, New Jersey and 

Long Island); Schalk (1938, Cape Cod); McMaster 

(1954, New Jersey); Taney (1961a, b, Long Island); 

Krinsley and others (1964, Long Island); and Schlee 

and others (1964, Cape Cod). 

Bottom topography and its geologic significance 

were studied by Veatch and Smith ( 1939, submarine 

canyons and the continental slope); Murray (1947, 

Gulf of Maine); Torphy and Zeigler (1957, Northeast Channel); and Jordan (1962, Georges Bank). 

Murray (1947) pointed out and illustrated the 

sonically dual-bottom nature of some basins in the 

Gulf of Maine. Sand waves and sand ridges on 

Georges Bank were described by Jordan (1962) and 

Stewart and Jordan (1964). King (1967) has described the bathymetry and geology of a part of the 

Nova Scotian shelf just to the northeast of the area 

considered here. Uchupi has recently (1968) described the topography of the area here studied. 

He has prepared (1965a) a bathymetric chart of 

the area at the scale 1 :1,000,000 and contour intervals of 20 and 200 m. 

METHODS 

A total of 913 bottom samples were analyzed, of 

which 487 were collected as part of the cooperative 

program of the U.S. Geological Survey and the 

Woods Hole Oceanographic Institution, 391 were 

collected and contributed by the Woods Hole Laboratory of the U.S. Bureau of Commercial Fisheries, 

33 were collected by the Woods Hole Oceanographic 

Institution, and 2 were collected by the U.S. Coast 

and Geodetic Survey. The distribution of these 

samples is shown in figure 1. Forty-five samples of 

beach sand were also analyzed. Nominal sample 

spacing on the continental shelf is 18 km, or 10 

nautical miles. Complete field data on all samples 

have been tabulated by Hathaway (1966, 1967). The 

number of samples from each major physiographic 

region and the average area represented by each 

sample are as follows: 

Number of Area mapped 

samples (Km2) 

Continental shelf _______ 756 229,600 

Continental slope _______ 104 32,900 

Continental rise ________ 53 84,300 

913 346,800 

Km2 per sample 

304 

316 

1,590 

A verage-737 

About half the samples were taken with a Campbell grab (Emery and others, 1965) and the remainder with a variety of tools. The material 

analyzed is assumed to represent the upper 15-20 

em of sediment, unless a marked change in compo-
SAND-SIZE FRACTION OF BOTTOM SEDIMENTS, NEW JERSEY TO NOVA SCOTIA K7 

sition was noted within that depth, in which cases 

the upper and lower materials were analyzed 

separately. 

The method of sample examination and presentation of results is that originated by Shepard and 

Moore (1954) and called by them the coarse-fraction 

method. On the Texas coast where they worked, the 

sand fraction is indeed the coarse fraction; but it is 

not in the glaciated area under discussion here, and 

here the technique will be termed "sand fraction 

analysis." The percentage of the sediment that is of 

sand size is shown in figure 2, which is drawn from 

data supplied by John S. Schlee. 

For each sample, a representative subsample was 

nondestructively disaggregated, dry sieved at 2 mm, 

wet sieved at 0.062 mm, and dried to obtain the sand 

fraction (0.062-2 mm). Samples were examined 

under a binocular microscope, and the percentage 

of major component groups was estimated by using 

percentage diagrams (Terry and Chilingar, 1955) 

and counts of 200--300 grains. Major component 

groups were rock fragments, quartz plus feldspar, 

0 50 100 150 MILES 

0-25 

0 50 100 150 KILOMETERS 

CONTOURS IN METERS 

EX PLANATION 

26-50 51- 75 

PERCENT 

1111111111111111111111111 

76- 99 100 

FIGURE 2.-Percentage of sand-sized material in original sample. Drawn from data 

supplied by John S. Schlee. 
K8 ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

dark minerals, glauconite, mica, Foraminifera, and 

shell fragments. The presence and relative amount 

of a number of other usually minor components 

were also recorded. These included pyrite, limonite, 

cinders, wood fragments, fibrous plant material, 

sponge spicules, urchin spines, ostracodes, diatoms, 

radiolarians, and scolecodonts. 

The mapped area was then divided into subareas, 

each of a distinctive sediment type. That division 

was based on the results of the preceding examination, on the color and overall appearance of the 

original samples, and on particle-size distribution 

data provided by John Schlee. Within each of the 

subareas, representative samples were sieved into 

five size grades with the limits 2, 1, 0.5, 0.25, 0.125, 

and 0.0625 mm. Each size-grade of each sample was 

examined to determine composition by percentage. 

By averaging results within each area, the composition by size grades of each area was determined and 

plotted graphically (fig. 15). 

In addition, roundness, sphericity, and degree 

of frosting and of iron staining were estimated on 

100-grain counts of quartz grains in the 0.25- to 

0.5-mm size grade, and the mineralogy and morphology of grains of the authigenic minerals glauconite 

and pyrite were studied. 

The work reported here depends on the assumption that a 1-gram split of a half-liter sediment 

sample can represent the sediment of an area of 

more than 300 km2 • Assuming that the split is representative of the sample, the validity of that assumption depends on the rate of variation in the 

sediment with distance. In this area, the assumption 

is at least workably valid for the continental rise 

and most of the continental slope, for the samples 

adequately portray the gradients of compositional 

and textural change. The same is true of most of 

the continental shelf. However, in the central and 

northern Gulf of Maine, in some nearshore areas, 

and in most protected bodies of water, the rate of 

change of sediment character with distance is very 

high. The samples from those areas probably typify 

the sediments but do not portray local trends of 

variation. A sample spacing on the order of at least 

1 km would be necessary to define individual areas 

of sediment types in those places. 

ACKNOWLEDGMENTS 

The cooperation and skill of Captain Harry H. 

Seibert and the officers and crew of the RV Gosnold, 

and of Captain Arthur D. Colburn of the RV 

Asterias, made possible the marine sampling program. Many persons made up the scientific complement of numerous sample-collecting cruises on RV 

Gosnold and RV Asterias, and particular thanks are 

due William R. Moehl and Arthus E. Wegweiser. 

Numerous additional samples utilized in the study 

were contributed by ·the Woods Hole Laboratory of 

the U.S. Bureau of Commercial Fisheries, and by 

Howard L. Sanders and Richard M. Pratt of the 

Woods Hole Oceanographic Institution. Many of 

the samples from present-day beaches were collected and made available by John M. Zeigler and 

William D. Athearn of the Woods Hole Oceanographic Institution. 

Kenneth 0. Emery and numerous colleagues on 

the immediate staff of the U.S. Geological SurveyWoods Hole Oceanographic Institution Continental 

Margin Project were of great help in the preparation of this report and in contributing data on 

which much of it is based. Numerous members of 

the scientific community in Woods Hole-on the 

staffs of the Oceanographic Institution, the Bureau 

of Commercial Fisheries, and the Marine Biological 

Laboratory-have supplied specialized information 

in many fields. Particular thanks are due Roland 

L. Wigley and Arthus S. Merrill of the U.S. Bureau 

of Commercial Fisheries and Thomas J. M. Schopf 

of the Marine Biological Laboratory. Joseph R. 

Frothingham, Jr., and Arthur C. Laura assisted in 

the laboratory preparation of samples. 

AREAL DISTRIBUTION OF COMPONENTS 

Most of the surface sediments of the continental 

shelf in the area of investigation are detrital in 

or1gm, with subordinate amounts of biogenic 

material, and, in some areas, minor amounts of 

authigenic material. The sand-size fraction of sediment on the continental slope is also predominantly 

detrital, but with a biogenic component that increases with depth. Biogenic material, primarily 

foraminiferan tests, predominates in the sand-size 

fraction of continental rise sediments. 

DETRITAL COMPONENTS 

Rock Fragments 

The percentage of rock fragments in the sandsize fraction is shown in figure 3. Highest concentrations are found on the glaciated Nova Scotian 

shelf and in the Gulf of Maine. In an area west of 

the southern Nova Scotia peninsula, percentages of 

rock fragments are consistently between 25 and 65; 

on the outer seaward Nova Scotian shelf, they are 

20-40 percent. In the south-central Gulf of Maine 
SAND-SIZE FRACTION OF BOTTOM SEDIMENTS, NEW JERSEY TO NOVA SCOTIA K9 

and Northeast Channel, percentages are in the 6-30 

percent range. 

These high percentages result from the glacial 

origin of the surface sediment. In glacial erosion, 

mechanical size degradation is more important than 

chemical weathering, so that intergrain bonds are 

preserved more often than in chemical weathering. 

Postdepositional processes that have operated on 

the glacial material include (1) turbulence, abrasion, 

and winnowing away of small particles accompanying passage of the shoreline zone during glacial-stage 

changes of sea level, and (2) the present-day action 

"'&. 

'\0 

of currents in selective removal of fine particles 

and perhaps, in shallower areas, ii). mechanical abrasion. Selective removal of fine sand by both these 

processes has resulted in high percentages of rock 

fragments in the coarse (1-2 mm) lag fraction. 

Georges Bank is a shallow high-energy area, and 

the sand fraction of its shallower parts contains 

almost no rock fragments. In its shoaler areas, much 

sand transport occurs during each tidal cycle 

(Stewart and Jordan, 1964). Low concentrations of 

rock fragments there are probably due to abrasion, 

and pr-obably also in some degree to an admixture 

., 

7o 

'o"i, 

0 50 100 150 MILES 

0 

0 50 100 150 KILOMETERS 

CONTOURS IN METERS 

EXPLANATION 

Trace 1- 4 

PERCENT 

5-16 

FIGURE 3.-Percentage of rock fragments in sand-size fraction. 
K10 ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

of highly quartzose reworked sediments of Cretaceous and Teritiary age. An area of zero rock fragments atop the bank continues over the northwestern boundary slope of the bank and occupies 

a small part of the floor of the Gulf of Maine at 

depths as great as 180 m, suggesting sand transport 

from the top of the bank. The northeastern end and 

western side of Georges Bank have as much as 5 

percent rock fragments in depths as shallow as 60 m. 

Several places on the continental slope southeast of 

Georges Bank have as much as 3 percent of rock 

fragments, which also indicates sand transport from 

the top of the Bank. 

The sands of Nantucket Shoals contain 1 percent 

or more of rock fragments. The shoals are as shallow and are probably of as high an energy level as 

the top of Georges Bank, which has less rock fragments. This situation may indicate continuous 

nourishment of Nantucket Shoals by glacial debris 

from the Cape Cod-Nantucket area. 

Rock fragments are few or lacking on glaciated 

shelf areas occupied by fine-grained postglacial sediments. Such areas include Roseway and La Have 

Basins on the Nova Scotian shelf, numerous basins 

in the Gulf of Maine, protected bays and areas near 

large river mouths along the coast of Maine, and 

the eastern half of Cape Cod Bay. 

The surface sediments of the continental shelf 

south of New England and Long Island generally 

contain less than 1 percent rock fragments. Exceptions are shallow inshore areas such as Long Island 

and Block Island Sounds, the Narragansett Bay 

area, Buzzards Bay, and Vineyard and Nantucket 

Sounds, which have from 1 to 8 percent rock fragments. Those areas are within the limits of glaciation and are floored with sediment transported only 

short distances (if at all) from the parent glacial 

deposits. Other exceptions are two areas on the 

open shelf. Sediments on the midshelf off New Jersey 

contain 3-5 percent rock fragments. 'This is an area 

of gravel that originated as a river deposit during 

a low stand of the ocean (Schlee, 1964). The same 

explanation probably applies to an area centered 45 

km south of Montauk Point. 

The continental slope and upper rise off the northeastern end of Georges Bank and off Nova Scotia 

commonly have from 1 to 4 percent rock fragments, 

but on the slope and rise off Northeast Channel, 

percentages rise sharply to as much as 15 percent. 

Many of the rock fragments are of igneous or metamorphic origin. It seems clear that glacially derived 

material from the Georges Bank and from the Nova 

Scotian shelf has been carried down the slope and 

upper rise and that material of an even more 

strongly glacial aspect was transported out of Northeast Channel and down the slope and rise. 

Surface deposits of the continental slope and rise 

southwestward from Bear Seamount are almost 

entirely lacking in rock fragments. The rock fragments found on the upper slope on each side of the 

Hudson Canyon are seaward continuations of the 

areas on the shelf off New Jersey and Long Island 

that contain high percentages of rock fragments. 

Two anomalous samples from the continental rise 

south of Bear Seamount in depths of 3,820 and 

3,975 m each contain 1 percent rock fragments. The 

fragments are as much as 5 mm across and are 

predominantly quartzite. The nearest samples in 

which rock fragments were found are 135 km landward. The presence of these rock fragments so far 

at sea indicates that a transporting mechanism 

brought them from at least as far away as the 

continental slope. 

Dark Minerals 

What are here termed dark minerals are primarily 

heavy minerals, which in this area have been studied 

by Ross (1967, 1970). Dark minerals excluding 

glauconite will be treated here as a unit co_mponent 

of the sediment. Their concentration ranges from 

zero in one sample from the outer continental rise 

to a maximum of 11 percent in the northern Gulf 

of Maine (fig. 4). 

Nearly all the Gulf of Maine has 2 percent or 

more dark minerals in the sand-size fraction, and 

5-10 percent is common in the northeastern Gulf of 

Maine and the entrance to the Bay of Fundy. The 

concentration of dark minerals in the Gulf of Maine 

shows little relation to topography, but Roseway and 

La Have Basins have less than the surrounding Nova 

Scotian shelf. 

The shallower parts of Georges Bank have only 

trace amounts of dark minerals. On the northwestern side of Georges Bank, the area of trace 

amounts extends deeper than 200 m in one area, 

and a wide 1-percent zone borders the bank. That 

is an anomalously small amount of dark minerals 

for the floor of the Gulf of Maine. The cause is 

probably the transportation of clean quartz sand 

from the top of Georges Bank. The same phenomenon is apparent on the seaward side of Georges 

Bank, which is the only place in the mapped area 

where the continental slope has less than 1 percent 

dark minerals. 
SAND-SIZE FRACTION OF BOTTOM SEDIMENTS, NEW JERSEY TO NOVA SCOTIA Kll 

Most of the shelf off Long Island and New Jersey 

has 2 percent dark minerals. Three to four percent 

dark minerals is present on the midshelf off New 

Jersey and south of the eastern tip of Long Island 

where areas of gravel are present. Eastern Long 

Island Sound has 3-5 percent dark minerals because 

strong currents are eroding and transporting glacially derived material. The dark-mineral content 

of the six samples taken in Narragansett Bay agrees 

with those reported by McMaster (1962), who found 

that almost three-fourths of his 15 samples had 

between 2 and 4 percent heavy minerals. 

River sediments also have high dark-mineral percentages, probably because those sediments are derived mostly from glacial deposits. A sample from 

the Thames River in eastern Connecticut had 6 

percent dark minerals, one from the Connecticut 

River had 4 percent, and several from the Hudson 

River had 3-5 percent. The Raritan River, with 5 

percent in one sample, and Raritan Bay, with 7 

percent in one sample, may owe their high darkmineral content to the erosion of strata of Cretaceous 

and Teritiary age in which dark minerals had previously been concentrated. 

0 50 100 150 MILES 

0 Trace 

0 50 100 150 KILOMETERS 

CONTOURS IN METERS 

E X PLAN A TION 

2 

PERCENT 

1111111111111111111111111 

3-4 5+ 

FIGURE 4.-Percentage of dark minerals in sand-size fraction. 
K12 ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

Excepting unusual areas, continental slope sediments contain about 1 percent dark minerals in their 

sand-size fraction. The slope near the edge of the 

mapped area southwest of Hudson Canyon has 2-3 

percent dark minerals at a depth of about 1,800 m. 

No reason for these anomalously high values at that 

depth is evident, hut they are probably related to 

the gravel deposit on the shelf in this area, with 

its high percentages of dark minerals and rock fragments. Higher than ambient amounts of dark 

minerals (2 percent) are present in several small 

areas along the continental slope and upper rise 

south of New England. They may be related to 

eroded outcrops of Cretaceous and Tertiary strata 

higher on the slope. As is true of rock fragments, 

the continental slope and upper rise seaward of 

Northeast Channel have anomalously high concentrations of dark minerals ( 3-4 percent), again showing that the channel has been a conduit for the 

seaward transport of sediments from the Gulf of 

Maine. 

Continental rise sediments contain as much as 1 

percent dark minerals. The line between trace 

amounts and 1 percent dark minerals is at about 

3,200 m depth everywhere southwestward of Bear 

Seamount, but off the northeastern tip of Georges 

Bank it is in less than 1,000 m. 

It seems a general rule that the more directly 

a sediment is derived from glacial material, the 

higher the content of both rock fragments and dark 

minerals. McMaster (1962) found a similar relationship in the sediments of 'Narragansett Bay. 

Goodell (1966) reported that glacial marine deposits 

of the Antarctic Continental Shelf and Slope in some 

places contain more than 15 percent heavy minerals. 

Mica 

The distribution of mica in the sand-size fraction 

of surface sediments (fig. 5) is an indicator of relative present-day energy levels. Because of their 

shape, mica particles are readily removed from highenergy areas and transported to, and deposited in, 

low-energy areas. 

The floor of the Gulf of Maine and the Nova 

Scotian shelf has only trace amounts of mica in the 

sand-size fraction in areas other than basins. In 

both areas major basins are fairly well delineated 

by areas of 1-2 percent mica and more. Nearshore 

basins off eastern Massachusetts and southern Maine 

have high mica contents because they are close to 

the two main mica sources : shoreline erosion of 

glacial deposits and stream and river mouths. The 

sediments of protected waters of the southwestern 

part of the Maine coast commonly have as much as 

8 percent mica, whereas those of protected waters 

in the Penobscot Bay-Mount Desert Island area do 

not exceed 4 percent. Differences in degree of protection and in tidal range may account for this. 

No mica is found in the high-energy environments 

of Georges Bank, Nantucket Shoals, and Browns 

Bank, nor on the floors of Great South Channel and 

Northeast Channel. Presumably this absence of mica 

is due to the winnowing effect of tidal currents. 

Stellwagen Bank, a shallow high-energy sandcovered area north of the tip of Cape Cod, lacks mica 

for the same reason. The effect of high-energy 

shoreline conditions is seen in the narrow zero-mica 

band east of the beaches of Cape Cod. Presumably 

tidal scour is also the cause of the zero-mica areas in 

Nantucket Sound and southwest 0f Martha's Vineyard. Inside the hook of Cape Cod is a concentration 

of as much as 5 percent mica, a result of low-energy 

conditions in those protected waters. 

Most of the continental shelf south of New 

England and Long Island has only trace amounts of 

mica. A notable exception is an anomalous mid-shelf 

and outer-shelf area south of Martha's VineyLrd, 

where fine-grained sediments contain as much as 3 

percent mica. This is the only place on the continental shelf other than basins and nearshore protected 

areas where mica is present in appreciable amounts. 

Long Island Sound also illustrates the relation 

between energy levels and deposition of mica. The 

highest mica concentrations are where the Sound is 

broadest and the tital currents correspondingly least 

swift. The south shore of Long Island and the New 

Jersey coast, both low sandy barrier-beach areas, 

have narrow longshore zones lacking in mica, as 

expected in a high-energy environment. The cause of 

the zero-mica area at midshelf off the New Jersey 

coast is not apparent. This is in the area of high 

gravel, rock fragments, and dark minerals previously noted. 

The continental slope has a range of 0 to 12 percent mica, but most samples have from 1 to 4 percent. 

High-energy conditions near the shelf break are 

indicated by three zero-mica areas southeast of 

Nantucket. At the seaward edge of Georges Bank, 

samples from slightly more than 200 m deep are 

lacking in mica. The strong concentration of mica 

on the upper continental slope just southwest of the 

Hudson submarine canyon may well be related to 

the deposition of river sediments to form the 

Hudson apron when most of the shelf was subaerial 

during Pleistocene glacial periods, as discussed by 
SAND-SIZE FRACTION OF BOTTOM SEDIMENTS, NEW JERSEY TO NOVA SCOTIA K13 

Ewing, Le Pichon, and Ewing (1963). Southwest of 

Georges Bank, the mica concentration in slope sediments increases with depth to a maximum between 

1,500 and 2,200 m. In deeper water the concentration 

decreases, and only trace amounts are present on 

the outer continental rise. On the continental slope 

and upper rise northeast of Georges Bank, the 

maximum mica concentration is at a depth of 1,500 

m. Beyond that, there is a decrease with depth that 

is more rapid than in the area to the southwest of 

Georges Bank. 

Quartz and Feldspar 

Except for the continental rise, where tests of 

planktonic Foraminifera predominate, quartz and 

feldspar grains dominate the composition of the 

sand-size fraction of nearly all surface sediments in 

the mapped area. This is because (1) the surface 

sediments are predominantly of detrital rather than 

of authigenic or biogenic origin; (2) the rocks of 

the mapped area itself and of the source areas of 

glacial and stream transport are highly quartzitic; 

and (3) quartz is more resistant to mechanical and 

0 50 100 150 MILES 

-0 50 100 !50 KILOMETERS 

CONTOURS IN METERS 

EX PLANATION 

1111111111111111111111111 

0 Trace 1-2 3-4 5+ 

PERCENT 

FIGURE 5.-Percentage of mica in sand-size fraction. 

472-1 99 0- 72 - 3 
K14 ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

chemical degradation than most other constituents 

of the sand-size fraction. Because quartz dominates 

most samples, variations in the percentage of quartz 

and feldspar in the sand-size fraction of surface 

sediments (fig. 6) are more readily explained by the 

presence or absence of other constituents than by 

absolute changes in the concentration of quartz and 

feldspar. 

Quartz and feldspar are considered together as one 

constituent for purposes of this study. In general it 

may be said that little feldspar is present in the 

sand fraction in the nonglaciated parts of the 

mapped area, and appreciable quantities are present 

in the glaciated areas. According to John Hathaway 

(oral commun., 1966), typical ratios between feldspar and quartz in all size classes smaller than 2 mm 

are 1 :2 to 1 :4 in the Gulf of Maine, 1 :4 to 1 :8 in the 

area of fine-grained sediments on the shelf south of 

Martha's Vineyard, and less than 1:8 on the shelf 

south of Long Island. 

The mapped area may be divided into three parts 

with respect to concentration of quartz and feldspar : 

glaciated shelf areas, nonglaciated shelf areas (including Georges Bank), and the continental rise. 

0 50 100 150 MILES 

0 50 100 150 KILOMETERS 

CONTOURS IN METERS 

EXPLANATION 

1111111111111111111111111 

0- -19 50-84 85 ~0 9-l - 97 98-99 100 

PERCENT 

FIGURE 6.-Percentage of quartz and feldspar in sand-size fraction. 
SAND-SIZE FRACTION OF BOTTOM SEDIMENTS, NEW JERSEY TO NOVA SCOTIA K15 

The continental slope is an area of transition between 

shelf characteristics and rise characteristics. 

Quartz-feldspar percentages on the glaciated shelf 

(Gulf of Maine and Nova Scotian shelf) are lower 

than those on the nonglaciated shelf, because in the 

glaciated areas dilution is caused by relatively high 

concentrations of rock fragments, dark minerals, and 

shell fragments. But within the Gulf of Maine, areas 

enriched in quartz-feldspar ( 94-97 percent of sandsize fraction) are found northwest of Georges Bank 

and southwest of the Nova Scotian shelf. This is 

probably caused by transport of, quartz grains 

toward the deeper basin center from those shoal, 

high-energy areas. A zone similarly enriched in 

quartz-feldspar parallels the coast from Cape Cod 

to Maine; it probably originated from reworking of 

glacial sediments. Offshore basins in the west-central 

and north-central Gulf of Maine have sediment that 

is almost wholly in the silt and clay sizes. Tlie sandsize fraction there is low in quartz-feldspar because 

few sand-size grains other than mica flakes and 

tests of Foraminifera and other biogenic material 

were deposited. 

Most of the continental shelf south of New England and Long Island has 94-99 percent quartzfeldspar. The median particle size of the entire 

sediment falls in the sand range. In Narragansett 

Bay and Long Island Sound, which show the effects 

both of glaciation and of low-energy postglacial deposition, quartz-feldspar content is diluted generally 

to the 85-93 percent range by appreciable amounts 

of primarily dark minerals, mica, and shell fragments. In Raritan Bay and the nearby inshore shelf, 

nonglaciated areas, high percentages of dark minerals and glauconite derived from erosion of the nearby 

and underlying strata of Cretaceous and Tertiary 

age have considerably diluted the quartz-feldspar 

content. 

The controlling principle that reworking of sediment in high-energy areas increases the quartzfeldspar content is best illustrated on Georges Bank, 

where most rock fragments have been degraded to 

their constituent mineral grains and the smaller 

grain sizes removed, leaving quartz as the strongly 

predominant component of the sand-size fraction. 

The amount and size of land-derived particles of 

sand size found on the slope and rise decrease rapidly 

with increasing depth and distance from the edge 

of the shelf. With a relatively uniform amount of 

sand-size foraminiferan tests being added to the 

slope and rise sediment, the ratio of land-derived 

quartz and feldspar to foraminiferan tests shows a 

continuous seaward decrease. The rate of decrease of 

quartz-feldspar content is 1.5-2.5 percent per 100 m 

change in depth; the rate of increase in foraminiferan tests is the same. 

Seaward of Georges Bank, the continental slope 

and upper rise have anomalously high concentrations of quartz and feldspar in the sand-size fraction. 

This enrichment is caused by highly quartzose sands 

of the bank being carried to and down the slope. 

In the Northeast Channel area and on the upper continental slope seaward of it, quartz-feldspar percentages are reduced by abnormally great amounts 

of rock fragments, dark minerals, Foraminifera, 

and shell fragments. 

On the continental rise, most samples from deeper 

than 2,400 m in the area southwestward from Bear 

Seamount have less than 10 percent quartz and 

feldspar in the sand-size fraction. The two major 

exceptions are a two-sample area 100 m south of 

Bear Seamount, where quartz-feldspar percentages 

are 55 and 83, and seven scattered anamalous 

samples with 53-75 percent quartz-feldspar, in 

depths ranging from 1,925 to 2,840 m. 

Glauconite 

Glauconite is widely distributed over the mapped 

area (fig. 7). Three types are present. The dominant 

type occurs as dark-green lobate grains with fractured surfaces. It is detrital in origin, having been 

reworked from beds of Cretaceous and Tertiary age. 

The other two types are authigenic in origin and are 

discussed under "Authigenic components." 

Detrital glauconite grains are found virtually 

everywhere that glauconite is shown in figure 7. The 

largest and least abraded grains are found in several 

relatively localized source areas, some of which have 

35 percent glauconite in the sand-size fraction. Progressively smaller grains showing the effects of 

abrasion and rounding are found at progressively 

greater distances from those source areas. The grains 

average 7501-' in diameter in the areas of very high 

glauconite concentration near land. Average grain 

diameter decreases to 3501-' to 4001-' on the inner 

shelf, to 250JL on the outer shelf and upper continental slope, and to 251-' to 100JL on the lower continental slope and the upper continental rise. 

The largest area of high glauconite concentration 

is on the extreme inner shelf between western Long 

Island and the northern New Jersey coast. Glauconite makes up from 10-35 percent of the sand-size 

fraction there. A sample from the present-day beach 

a few kilometers south of Sandy Hook contains 15 
K16 ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

percent glauconite; no other modern beach-sand 

sample area contains more than 1 percent. 

Nearly all the glauconite grains on the shelf between western Long Island and northern New Jersey 

are of the dark-green lobate type ("free-form" of 

Burst (1958, fig. 3d) ; probably "bulbous pellet" 

form of Ehlmann and others (1963)). They are 

strongly fractured, and their surfaces are divided 

into polygonal areas. A number of the fractures are 

open, and they are commonly oxidized brown at the 

surface of the grain. On a very small number of the 

grains, the surfaces themselves show slight oxidation. Dark-green lamellar grains ("accordian" forms 

of Galliher (1935) ; "tabular" forms of Light (1952)) 

are present in trace amounts. A small number of 

jade-green grains are also present in some samples. 

The lobate grains have very smooth surfaces, and 

the darker grains are shiny. Color of grains ranges 

from dark green (5GY 2/ 2) 2 to medium green 

(lOGY 4/ 6); rare grains are nearly black (7.5Y 

3/ 2). Roundness is 0.8-0.9 (rest-position outline, 

Krumbein, 1941), and Waddell projection sphericity 

2 Munsell system (Goddard and others, 1948). 

0 50 100 150 MILES 

0 

0 50 100 150 KILOMETERS 

CO NTOURS IN METERS 

EXPLANATION 

Trace 1-2 

PERCENT 

1111111111111111111111111 

3-4 5+ 

FIGURE 7.-Percentage of all types of glauconite in sand-size fraction. 
SAND-SIZE FRACTION OF BOTTOM SEDIMENTS, NEW JERSEY TO NOVA SCOTIA K17 

(Rittenhouse, 1943) is 0.83-0.87, which is to say that 

the grains are highly rounded but rather imperfectly 

spherical. Grain size ranges from 250,u. to 1.25 mm. 

Lamellar grains are about 750p. in the direction 

normal to the plates and half that in the other 

directions. 

The area of high glauconite concentration lies 

directly along the strike of 11 glauconite-rich formations of Cretaceous and Tertiary age in the New 

Jersey coastal plain, and the offshore glauconite 

grains are similar in physical appearance to those 

found on land (Owens and Minard, 1960). The area 

is also along the strike of equivalent glauconitebearing formations known at shallow depth in the 

subsurface of Long Island, where they are for the 

most part covered by glacial deposits (Suter and 

others, 1949). It seems clear that the glauconite 

in the surficial shelf sediment in this area is derived 

from coastal plain beds, but whether from those now 

exposed subaerially in New Jersey or from their 

equivalents underlying the continental shelf is not 

clear. The shelf glauconite grains are much and 

deeply fractured, but nearly all grains are entire; 

few fragments are present. This suggests that the 

grains have undergone little transportation and 

therefore have come from underlying strata. 

Large glauconite grains of the detrital type showing little abrasion are also found in high concentration (35 percent) in one sample from 27 km 

southeast of the eastern tip of Long Island. Most 

of the surrounding samples contain less than 1 percent glauconite. The glauconite grains of this sample 

are darker green and are slightly smaller (average 

150p.-300JL) than the grains near the northern New 

Jersey coast. The sample probably represents a. 

residual deposit eroded from a local outcrop of 

strata of Cretaceous or Teritiary age on the continental shelf. 

Concentrations of detrital-type glauconite (as 

much as 15 percent of the sand-size fraction) are 

found on nearly all sides of Georges Bank and on 

the continental slope south of New England. Strata 

of Cretaceous and Tertiary age underlie Georges 

Bank and crop out in canyons cutting the slope 

south of New England ; they are the sources of this 

glauconite. 

Detrital glauconite grains are mixed with glacially derived sediments in the central Gulf of Maine 

and on Browns Bank and the outer Nova Scotian 

shelf. They indicate the presence of glauconitebearing Cretaceous or Tertiary strata over those 

areas at the time of glaciation. Such strata have 

been detected in only a part of the area in which 

glauconite grains occur (fig. 8), but it is possible 

that they are present but are not thick enough to be 

detected by the seismic method employed. Glauconite 

is also present in glacial outwash on outer Cape Cod 

(Zeigler and others, 1964). 

Hard medium-green detrital glauconite is also 

present in trace amounts in a six-sample area at the 

entrance to the Bay of Fundy. Westward and north0 100 200 300 MILES 

0 100 200 300 KILOMETERS 

CONTOURS IN METERS 

EXPLANATION 

Tertiary 

Cretaceous 

Pre-Triassic igne ous and metamorphic 

rocks and Jurassic igneous rocks 

Northwestern limit of detrital-type glauconite grains in present-day surface 

sediments 

FIGURE 8.- Inshore limit of glauconite in surface sediment, 

and inferred present-day extent of sedimentary rocks in 

the Gulf of Maine. Dotted line is from figure 7, this report. 

Other information is from Uchupi (1966), Schlee and 

Cheetham (1967), and Chute ( 1965), and is based largely 

on interpretation of continuous seismic profiler records. 
K18 ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

ward transport by marine currents from the shallow 

shelf south and southeast of Nova Scotia is the only 

reasonable explanation of its origin. Glau(Conite 

was not detected by Forgeron in his study of Bay of 

Fundy bottom sediments (written commun., 1966), 

and glauconite-bearing source rocks are not known 

beneath the bay or within the drainage area of 

streams entering the bay (Tagg and Uchupi, 1966; 

Donald Swift, written commun., 1966). 

In some samples from widely scattered areas of 

the continental shelf, detrital-type glauconite grains 

have a brown surface stain of ferric oxide. This 

oxidative process implies, but does not require, a 

history of subaerial exposure (Pratt, 1962, p. 212). 

The staining probably originated subaerially during 

glacial-stage lowering of sea level. Most of the 

stained samples are from depths of 163 m or less, 

which is approximately the upper limit of present 

estimates of the amount of lowering of sea level. 

The great majority of samples from the continental 

shelf lack stained glauconite; abrasion in the transgressing surf zone would have tended to remove 

the soft brown oxide from the grains. Most samples 

containing the brown grains are from the outer 

shelf, near where strata of Tertiary age are exposed 

or are only thinly covered. Probably those samples 

were not subjected to the abrasion of the surf zone 

over a long period, as were the samples from most 

of the shelf. Alternatively, the brown-stained grains 

may have been oxidized before being eroded from 

the strata in which they originated. 

In samples distant from glauconite source areas, 

on the continental.shelf as well as on the slope and 

' rise, detrital glauconite is mostly in the form of 

small highly rounded fragments. Glauconite grains 

in such areas have lost their original surface polish 

and do not show surface oxidation. Some of them 

show a color shift from dark green to medium green. 

This is probably also a result of abrasion, because 

the inside of unabraded grains is the same shade 

as that of the small abraded grains. Where this type 

of glauconite grain is found, quartz grains lack 

iron staining, and the sand-size fraction is light 

gray. Samples of this type on the continental shelf 

above the level of maximum sea level lowering indicate areas where sediment has undergone transportation and abrasion during or since the postglacial transgression. 

BIOGENIC COMPONENTS 

Foraminifera 

The percentage of Foraminifera in the sand-size 

fraction of surface sediments is shown in figure 9. 

In the following discussion, the statement that 

Foraminifera were not observed does not mean that 

they are totally lacking, but rather that scrutiny of 

a few grams of material under the microscope did 

not reveal any. Specialized separation techniques 

applied to a larger sample would reveal Foraminifera 

in most cases. In addition, many arenaceous Foraminifera probably were destroyed during drying and 

mechanical and ultrasonic disaggregation of finegrained samples (Phleger, 1960, p. 37-38), though 

many were still observed. 

Almost no Foraminifera were found near th~ 

eastern Massachusetts and New Hampshire coasts 

and much of the coast of Maine, including numerous 

small basin area as much as 50 km offshore. Banks 

in the Gulf of Maine also tend to lack Foraminifera, 

particularly in the central and western parts. Bottom 

currents probably have higher velocities over banks 

than in deeper water, and they thus tend to prevent 

accumulation of such small and light particles as 

foraminiferan tests. 

In some of the Gulf of Maine basins of low-energy 

sedimentation, the percentages of Foraminifera in 

the sand-size fraction are very high. In the Wilkinson-Murray Basin, for example, three samples contained more than 70 percent Forminifera in the 

sand fraction. Northeast of that basin, nine other 

samples from in or near other basins contained from 

20-90 percent Foraminifera. Most of the sediment 

in these basins (with the exception of mica flakes) 

is finer than sand size, and thus biogenic material, 

largely foraminiferan tests, predominates in the 

sand-size fraction. The three samples from the 

Wilkinson-Murray Basin contain an average of only 

0.1 weight percent of sediment larger than 62~-t. 

Sediments in a large area off the southwestern 

coast of Nova Scotia and in a belt from there to the 

northern Maine coast contain from 1-4 percent 

Foraminifera, and one sample from Roseway Bank 

seaward from Nova Scotia contains 15 percent. 

These concentrations are higher than are to be 

expected from generally high-energy areas. High 

organic productivity is probably the cause of these 

high concentrations. 

Another area of anomalously high Foraminifera 

content comprises the floor and flanks of Northeast 

Channel and the adjacent eastern tip of Georges 

Basin with as much as 8 percent Foraminifera; the 

northeastern tip of Georges Bank, with 8-15 percent; and the southern tip of Browns Bank, with 

25-30 percent. The Foraminifera population in this 

general area is made up largely of heavy current-
SAND-SIZE FRACTION OF BOTTOM SEDIMENTS, NEW JERSEY TO NOVA SCOTIA Kl9 

resistant benthonic forms. Ecologic factors probably 

also cause this localized area of high foraminiferan 

productivity. 

On Georges Bank and the open continental shelf 

between it and New Jersey, where the bottom sediment is mainly well-sorted quartz sand, Foraminifera are very sparse in depths less than about 70 m, 

and only trace amounts are present in depths between about 70 and 100 m. 

On the continental slope and rise, the percentage 

of Foraminifera increases rapidly with increasing 

depth. The sand-size fraction of most samples from 

0 50 

deeper than 2,800 m between New Jersey and Bear 

Seamount contains more than 90 percent Foraminifera. Several exceptions occur in a large area on 

the upper continental rise seaward of Hudson Canyon and .in an area south of Bear Seamount. In the 

latter area two samples from 2,722 and 2,682 m 

contained only 30 and 40 percent Foraminifera, 

respectively. 

Seaward of Georges and Browns Banks, sediments 

of the lower continental slope and upper continental 

rise have less Foraminifera than are present at 

comparable depths south of New England. Assuming 

100 150 MILES 

50 100 150 KILOMETERS 

CONTOURS IN METERS 

EXPLANATION 

1111111111111111111111111 

0 Trace 1- 4 5-16 17-64 65+ 

PERCENT 

FIGURE 9.- Percentage of Foraminifera in sand-size fraction. 
K20 ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

uniform productivity, this indicates that more 

terrigenous detritus is being transported seaward 

from the banks than from the shelf to the southwest. 

Directly off Northeast Channel this effect of detrital 

dilution is especially marked: a sample from 2,474 

m contained only 2 percent Foraminifera. 

In two areas foraminiferan tests show effects of 

chemical solution: basins floored with low-energy 

sediments in the west-central and north-central parts 

of the Gulf of Maine, and the outer continental 

shelf and upper continental slope in depths less than 

460 m directly south of Martha's Vineyard. Most 

of the samples in which pyrite was observed are 

from those same two areas. Presumably, solution of 

calcium carbonate tests is caused by low pH within 

the upper part of the sediment. Formation of pyrite 

is caused by negative Eh at localized small centers 

within the sediment. Both effects are probably caused 

by the reduction of organic matter in the sediment. 

The two areas in which both phenomena were observed have fine-grained sediments, which are able 

to accumulate high amounts of organic carbon and 

which limit the circulation of interstitial water, thus 

permitting the formation of reducing microenvironments. 

Shell Fragments 

Shell fragments are predominantly those of 

mollusks, with pelecypods strongly predominating, 

and usually a minor amount of gastropods. At the 

northeastern end of Georges Bank, unusually great 

numbers of immature pelecypods, 2-3 mm in diameter, were observed. The shell fragments from one 

sample in that area consist almost entirely of single 

and clustered serpulid worm tubes. Numerous 

samples from the Nova Scotian shelf and one from 

the coast of Maine contain considerable amounts of 

barnacle fragments. In sandy areas, particularly off 

New Jersey, Long Island, and southern New England, fragments of sand dollars predominate. 

The concentration of shell fragments is shown in 

figure 10. Most of the Gulf of Maine, Georges Bank, 

and the continental shelf south of New England 

and Long Island and east of New Jersey have no 

more than trace amounts of shell fragments, although some scattered single samples have 5-12 

percent. High concentrations of shell fragments 

are found on Nantucket Shoals, on the northeastern 

tip of Georges Bank, and in an area extending from 

the northeastern coast of Maine through the nearshore shelf southwest of Nova Scotia to Browns 

Bank. Most of the shell fragments in those areas 

appear to be from massive shells, indicative of the 

high-energy conditions of the areas in which they 

are found. This distribution substantiates the observation (based on the distribution of Foraminifera) that the Nova Scotian shelf is an area of high 

organic productivity. 

The protected waters of Vineyard Sound, N arragansett Bay, Long Island Sound, Raritan Bay, 

and some areas along the coast of Maine also have 

high concentrations of shell fragments. Most samples 

have from 1 to 4 percent, but some contain as much 

as 30 percent, indicating wide variability over short 

distances. The inshore molluscan shells are mainly 

thin shelled, indicative of an infauna suited to living 

in a low-energy environment. In some of these inshore areas, the scarcity of detrital particles of 

sand size acts to increase the percentage contribution 

of shell fragments. 

With few exceptions, shell fragments were not 

observed in samples from depths greater than about 

200 m. 

Other Biogenic Components 

Shell fragments and Foraminifera dominate the 

biogenic components of the sand-size fraction, but a 

number of other forms are present. Those that occur 

in significant amounts include sponge spicules, 

echinoid spines, diatoms, radiolarians, ostracodes, 

scolecodonts, polychaete acicula, and wood fragments. 

Sponge spicules are found nearly everywhere in 

the Gulf of Maine and on · the continental slope and 

rise (fig. llA). They are almost entirely absent on 

the sandy shelf east of New Jersey and south of 

Long Island and New England, and in the Nantucket 

Shoals-Georges Bank-Browns Bank area. They are, 

however, present throughout a large area of the 

middle and outer shelf south of Cape Cod and 

eastern Rhode Island ' where the bottom sediments 

have a high content of silt- and clay-sized particles. 

Most of the spicules are broken, the fragments 

commonly being 2-3 mm long. Some fragments are 

branched but most are not. 

Two distinct types of echinoid spines are present 

in the surficial sediment over large areas; the distribution of each is shown in figure llB. Those spines 

here designated type A have the appearance of 

bundles of clear glass fibers and are similar in appearance to spines of the sand dollar Echinarachnius 

parma. They occur in fine-grained sediments in the 

Gulf of Maine and on the inner shelf south of Long 

Island and Rhode Island. They are present in nearly 

all samples from the continental slope and rise, 
SAND-SIZE FRACTION OF BOTTOM SEDIMENTS, NEW JERSEY TO NOVA SCOTIA K21 

except for a deep-water area in the southeast corner 

of the mapped area. 

Echinoid spines of the type here designated type 

B are opaque and strongly ridged and tapered. They 

are similar in appearance to the spines of the purple 

sea urchin Arbacia punctulata. They were found 

only off the northeastern coast of Maine, on the 

Nova Scotian shelf, in Northeast Channel, on the 

northeastern end of Georges Bank, and in isolated 

areas on the flanks of Georges Bank and southeast 

of Cape Cod. Nearly all the samples in which they 

were found are coarse to very coarse gravelly sands 

or gravels with abundant coarse shell fragments. 

The maximum depth at which they were found is 

318 m. 

Diatoms and Radiolaria are rare in the bottom 

sediments of the continental shelf and the Gulf of 

Maine. As shown in figure llC, nearly all samples 

from deeper than 1,000 m contain both. In those deep 

samples, diatoms are usually present in trace 

amounts, but Radiolaria make up as much as 5 

percent of the sand-size fraction. The single notable 

exception is three samples from the continental slope 

and rise just outside Northeast Channel which are 

0 50 100 150 MILES 

0 50 100 150 KILOMETERS 

CONTOURS IN METERS 

EXPLANATION 

lllllllllllllllllllllllll 

0 Trace 1-4 5-16 17+ 

PERCENT 

FIGURE 10.- Percentage of shell fragments in sand-size fraction. 

472-199 0- 72-4 
K22 ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

lacking in both diatoms and Radiolaria. The samples 

are also anomalously low in Foraminifera and high 

in content of rock fragments. They indicate that 

shallow-water sediment is being carried through the 

Northeast Channel and being deposited on the continental slope and rise outside it. 

Ostracodes were found in the sand-size fraction 

of only 14 samples widely distributed through the 

mapped area. Doubtless they were present in far 

'10 

'"&, "'o, 0.; "'._o, 

A 

'1 ~· 

c 

0 100 

0 100 

more samples, but they were· not observed because 

no effort was made to separate the biogenic fraction 

of the sediment, and no special search for ostracodes 

was made. Intensive work on the ostracode population of the mapped area has been conducted by 

Hazel (1967). 

Scolecodonts, which are annelid worm jaws, are 

present in amounts of less than 1 percent of the 

sand fraction in many samples from the Gulf of 

'\a 

0</, "'&, 'orO "'o. "._o, 

B 

'\.; 

D 

200 300 MILES 

200 300 KILOMETERS 

CONTOURS IN METERS 

FIGURE H.-Distribution of minor biogenic components and pyrite in the sand-size fract ion. A, Distribution of sponge 

spicules. Stippling indicates concentration of less than 1 percent of sand fraction; line pattern indicates 1 percent 

or more. B, Distribution of type A (stippled) and type B (line pattern) echinoid spines. C, Distribution of scolecodonts (stippled) and of samples containing appreciable numbers of both radiolarians and diatoms (line pattern) . 

D, Distribution of pyrite (stippled) and of samples containing large am~mnts of wood fragments (line pattern). 
SAND-SIZE FRACTION OF BOTTOM SEDIMENTS, NEW JERSEY TO NOVA SCOTIA K23 

Maine and in a small number of samples from the 

continental slope (fig. llC). They were found only 

in fine-grained sediments. 

In most samples the scolecodonts are accompanied 

by dark-brown to black chitinous spicules, straight 

to slightly curved, pointed at one end, increasing 

uniformly in diameter to the other end, and measuring from 0.5 to 2 mm long and roughly 50,. wide 

at the wide end. They are thought to be annelid 

acicula (Shrock and Twenhofel, 1953, p. 511). 

Noncalcareous pearl-white circular objects 100,... 

to 200,... in diameter, in shape resembling cap mushrooms, were found in profusion (but less than 2 

percent) in a sample from near the head of Somes 

Sound, Mount Desert Island, Maine. They were also 

found in three samples from 10 miles off the coasts 

of northern Massachusetts and southern Maine. 

Wood fibers and fragments are present in most 

of the samples from the inshore and protected waters 

of the central Maine coast (fig. llD) . The sand-size 

fraction of samples from Boothbay Harbor, upper 

Penobscot Bay, the lower Penobscot River, and 

Union River Bay contains as much as 98 percent 

wood fragments. The valleys of the rivers entering 

these areas have been important lumber-producing 

areas for many years, and the material is simply 

sawdust. A small amount of black material showing 

woody structure is found at various places along the 

Maine coast and is thought to be the result of forest 

fires. Wood fibers and fragments are also present in 

trace amounts in the surficial sediment of the lower 

reaches of the Hudson and Raritan Rivers and in 

the Wilkinson-Murray Basin northeast of Cape Cod. 

Algal fibers and fragments are present in varying 

amounts in many nearshore samples throughout the 

area. In a sample from 1.6 km south of Martha's 

Vineyard, small black and very dark brown fragments showing woody structure are either mineralized or devolatilized wood. These are probably being 

eroded from nearby exposures of carbonaceous sedimentary rocks of Cretaceous and Teritiary age. 

Cinders from burned coal dumped by ships and 

barges are present in samples from off New York 

City and Boston and to a l~sser extent along the 

entire coast. The greatest concentration of cinders 

is in upper Penobscot Bay, the lower Penobscot 

River, and in Union River Bay, Maine. A sample 

from off the town of Belfast in upper Penobscot Bay 

contains 5 percent cinders in the sand-size fraction. 

Most other samples do not contain more than 1 

percent cinders, though a sample from 72 km east 

of the south end of Cape Cod surprisingly contains 

3 percent. 

AUTHIGENIC COMPONENTS 

Glauconite 

Glauconitic internal molds of Foraminifera are 

found in the surface sediment of the extreme outer 

shelf and the upper slope throughout almost the 

entire length of the mapped area. Their distribution 

is shown in figure 12. The Foraminifera are of both 

planktonic and benthonic types, and the test material 

around the molds is in some cases entire, in some, 

fragmental, and in some, lacking. The glauconite 

material ranges in color from light yellow brown 

(7.5Y 7 /3) through light and dark brownish greens 

(2.5GY 5/ 4 to 7.5GY 4/ 2) to a nearly black dark 

green (lOGY 3/ 1). A wide range of colors is present 

within several of the individual samples. It appears 

visually, on the basis of color and hardness of the 

material inside the tests, that all gradations from 

ambient buff-color clay to fairly highly organized 

glauconite are present within the tests. The glauconite molds are highly detailed and have smooth 

surfaces. 

Thomas G. Gibson of the U.S. Geological Survey 

examined the samples containing the molds and 

stated (written commun., 1966) that 

About 19 of the samples contain large enough numbers 

of glauconitized specimens to pick out a fairly good population or faunal sample. The 19 samples contain faunal 

assemblages similar to those now found in their respective 

-} Me./ ,· 

_\ 

r' 

0 100 200 300 MILES 

0 100 200 300 KILOMETERS 

CO NTOU RS IN METE RS 

FIGURE 12.-Distribution of glauconitic internal molds of 

Foraminifera. 
K24 ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

depths on the shelf or upper slope. Therefore, my opinion is 

that the glauconitization of these specimens is occurring 

in place. Species commonly found as internal molds include 

Bulimina marginata, A ngulogerina angulosa, Cassidulina 

crassa, and various species of Globerigerina. 

One interesting aspect is the rather selective glauconitization of the specimens according to species. The planktonic 

species, mainly speciEs of Globigerina, are much more readily 

preserved in this manner than the benthonic species. This 

could be due to aperture size as is commonly stated, and the 

Globigerina species do have generally large apertures in 

comparison to the other associated species, or it could be due 

to the comparatively large perforations in the test of 

Globigerina. As the filling takes place all the way to the tip 

or first chamber of the test, wall perforations are something 

deserving consideration. As the glauconitization is selective, 

care must be taken in environmental interpretations on the 

samples. 

Of the 57 samples in which glauconitic internal 

molds of Foraminifera were observed, 49 are from 

depths of 87- 292 m. The remaining eight are from 

depths between 346 and 802 m, and the molds in 

several of them show signs of transportation and 

abrasion. 

The fragility of the molds themselves and the 

fragility of the cracked tests and test fragments 

adhering to some of the molds argue against their 

exposure to high-energy conditions of the surf zone. 

The last time that the amount of sea-level lowering 

exceeded 80 m was on the order of 15,000 years ago 

(Shepard, 1963, fig. 3). At least some of this glauconite must have formed since that time. 

Another type of glauconite is present near the 

shelf break from the outer Nova Scotia shelf to the 

area southwest of Hudson Canyon. Its color ranges 

from moderately light slightly yellowish green 

(7.5GY 7/6) to moderate yellowish brown (5Y 7/4). 

The grains are mostly irregular in shape. Many of 

them are angular, and many are crudely pellet 

shaped. Surface fractures are more numerous and 

more closely spaced than those in dark-green 

detrital-type grains. Most grains are small (diameter 

100,u- 200,u), but some are fairly large (400,u). 

This material is thought to be of first-cycle authigenic origin rather than of detrital origin because 

( 1) the depths and areas in which it is found correspond closely to the depths and areas in which 

authigenic glauconite is found but do not correspond 

to the distribution pattern of detrital-type glauconite; (2) much of it is soft, deeply fractured, and 

fragile, yet it shows little effect of transportation; 

and ( 3) the dominant color is moderately light 

yellowish green, characteristic of immature glauconite. Most probably this type of glauconite originated in place in microenvironments of larger physical size than the interior of foraminiferan tests, 

perhaps in the internal cavities of larger organisms. 

The pellet-like shape of some grains suggest an 

origin from fecal pellets. 

Pyrite 

Pyrite is present in the sand-size fraction in the 

Wilkinson-Murray Basin and at a number of other 

scattered localities in the Gulf of Maine, and on the 

continental slope and upper continental rise south 

of Long Island and New England (fig. llD). In 

most samples it is present in trace amounts, but it 

makes up 3-4 percent of the sand fraction of a few 

samples. 

The pyrite occurs in four forms, of which the most 

common is rough-surfaced spherules lOOp. to 150,u 

in diameter. The next most common form is irregular 

angular masses and fragments that consist of 

clusters of gloubles. Some of these appear to have 

the shape of intergranular spaces. The third form, 

cylinders 50,u in diameter and generally 200,u to 300,u 

long, some circularly ridged, probably originated 

as internal molds of organisms or tubes. The fourth 

and rarest type is internal molds of Foraminifera. 

All four types appear both in the Gulf of Maine and 

on the continental slope. The spherulitic form is 

dominant in the clay and silty clay of the WilkinsonMurray Basin. 

The pyrite is of authigenic rather than detrital 

origin. Ninety percent of the samples containing 

pyrite in the sand-size fraction have median diameters smaller than 16.,u. The average organic carbon 

content of the pyrite-bearing samples is 1.07 percent 

(Jobst Hulsemann, oral commun., 1966). X-ray 

diffractometer analysis shows the material is pyrite 

rather than marcasite. 

The 32 stations at which pyrite was found range 

in depth from 86-2,187 m. Sixty percent of those 

stations are between 183 and 284m, and the median 

depth within that group is 220- 230 m. This is more 

likely a function of ambient basin-floor depths in 

the Gulf of Maine than of any depth control of 

pyrite formation, however. 

Limonite 

Trace amounts of limonite grains are present on 

the inner shelf south of New England and on the 

flanks of the northeastern end of Georges Bank. 

Alexander (1934) and Shepard and Cohee (1936) 

thought that at least some of the limonite south of 

New England was authigenic, but all or nearly all 

the limonite observed in this study appears to be 

detrital. This is particularly true of the most com-
SAND-SIZE F'RACTION OF BOTTOM SEDIMENTS, NEW JERSEY TO NOVA SCOTIA K25 

mon type, which is highly rounded and commonly 

has a smooth reflective surface. In size and shape 

those limonite grains are similar to the detrital 

glauconite of the area, and limonitically altered 

glauconite grains are common in outcrops and beach 

sands at the western end of Martha's Vineyard. 

CHARACTERISTICS OF QUARTZ GRAINS 

ROUNDNESS 

Roundness of quartz grains in the size range 0.25-

0.5 mm (fig. 13A) was estimated by comparing the 

rest-position outline of 50 or more grains with 

Krumbein's (1941, pl. 1) roundness chart. (Arithmetic mean roundness is reported here : the ratio 

of the average radius of curvature of the grain 

outline to the radius of the maximum inscribed 

circle.) The roundness numbers of the 129 samples 

examined range from 0.35 to 0.7. The median is 

between 0.45 and 0.5. 

Roundness is higher on the seaward edges of 

Georges and Browns Banks and on the continental 

slope seaward of the banks than it is on the shallowest parts of the banks. Similarly, roundness is higher 

in a crescent-shaped shelf area south of Nantucket 

and Martha's Vineyard and on the adjacent continental slope than it is over most of the nearby 

Nantucket Shoals. Thus quartz grains are rounder 

seaward of the present-day shoals than they are 

on those high-energy areas of high grain abrasion 

to which little or no sediment is being added. 

The explanation probably lies in the distribution 

(fig. 13D) of the very highly rounded and frosted 

quartz grains that are thought to have originated 

from the action of periglacial winds during glacialstage emergence of the continental shelf (Stetson, 

1934). Those grains are so nearly spherical that any 

appreciable admixture of them raises the roundness 

index of the sediment containing them. The presentday distribution of the very highly rounded grains 

along the outer shelf seems to indicate either that 

the highly rounded grains were not formed over 

most of the shallower parts of the shelf, or that the 

turbulence on the shallow part of the shelf has 

destroyed their roundness or greatly diluted them 

since they were formed. 

Quartz grains show least rounding in the Gulf of 

Maine and on the Nova Scotian shelf. This is because the primary sediment source there is till. 

SPHERICITY 

Waddell projection sphericity of 0.25- to 0.5-mm 

quartz grains was calculated for 44 samples from 

the Gnlf of Maine, Georges Bank, and the continental shelf and slope southwestward from Georges 

Bank. Fifty-grain counts were made using Rittenhouse's (1943, fig. 1) visual chart. Values ranged 

from 82.2 to 85.9. The values showed no geographic 

coherence or relation to any property of the sediment, although the samples were from a wide range 

of depths and sediment types. On the south shore 

of Long Island, Taney (1961b) found that roundness increased westward, in the direction of sediment 

transport, as is also shown in figure 13A; sphericity 

did not show such a relation. 

FROSTING 

The distribution of frosted quartz grains was 

determined by 100-grain counts of 0.25- to 0.5-mm 

grain in 129 samples and is shown in figure 13B. 

Areas with the greatest number of frosted grains 

are Georges Bank, the outer shelf south of Nantucket, and nearly the full width of the shelf eastward from New Jersey. The maximum concentration 

is on the outer shelf south of Nantucket, where 

27 percent of the grains are frosted. The concentration in that area and on part of Georges Bank 

is caused in part by an admixture of the distinctive 

very rounded frosted grains discussed in a succeeding section. Those distinctive grains have a 

median diameter of about 0.5 mm, and their distribution therefore does not correspond closely to 

the distribution of 0.25- to 0.5-mm grains in figure 

13B. 

IRON-STAINED GRAINS 

The amount of surface iron staining on quartz 

grains was determined by 100-grain counts of 0.25-

to 0.5-mm grains in 192 samples. The resulting map 

(fig. 13C) shows that the largest area of heavy 

iron staining is in and near the mouth of the Bay 

of Fundy, where 45-62 percent of the grains are 

iron stained. This color is an inheritance from the 

red sedimentary rocks of Triassic age now exposed 

in Nova Scotia and New Brunswick and known to 

be present beneath the Bay of Fundy and a contiguous part of the Gulf of Maine (Tagg and Uchupi, 

1966). 

Most of the rest of the Gulf of Maine and the 

continental shelf of Nova Scotia has relatively highly 

iron stained quartz grains. Iron-stained grains also 

are found around most of the periphery of Georges 

Bank. This staining may be due in part to each of 

the following: ( 1) Dissemination of grains from 

rocks of Triassic age from the source in the Bay of 

Fundy area; (2) inheritance from strata of Tertiary 

or Cretaceous age, especially at the margins of 
K26 

1 ~· 

ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

D ' -5.5 

E X PLANATION 

ROUNDNESS 

4.5-5.5 

Contour interval 0.5 

A 

'"o. ri 

< 4.5 

E X PLANATION 

IRON-STAINED GRAINS (PERCENT) 

D > 40 30-39 20-29 

c < 20 

0 100 

0 100 

D 

>10 

EXPLANATION 

FROSTED GRAINS (PERCENT) 

6-10 

10 <0 

B 

1-5 

"o, 

E X PLANATION 

0 

HIGHLY ROUNDED AND FROSTED GRAINS 

tPEl{CENT) 

D >20 2-19 

D 

200 300 MI LES 

200 300 KILOMETERS 

CO NTOURS IN METERS 

FIGURE 13.-Variation of characteristics of quartz grains. A, Roundness of 0.25- 0.5- mm grains. B, Frosting on 0.25-

to 0.5- mm grains. C, Iron staining on 0.25- to 0.5-mm grains. D, Highly rounded and frosted grains in the sand-size 

fraction . 
SAND-SIZE FRACTION OF BOTTOM SEDIMENTS, NEW JERSEY. TO NOV A SCOTIA K27 

Georges Bank; (3) subaerial weathering on the continental shelf during periods of glacially lowered 

sea level, and a lack of deposition since then· ( 4) 

inheritance from glacially transported grains 'originally stained subaerially in the soil profile, and little 

abraded since emplacement. The areas of highly 

stained grains southeast of Rhode Island and Long 

Island are probably caused by the second and third 

reasons listed above. The relative lack of iron-stained 

grains near shore from Cape Cod to northern Maine 

is a result of present-day deposition there of grains 

lacking staining. The relative lack of stained grains 

in the center of Georges Bank is due to grain abrasion and cleaning caused by strong tidal currents. 

Many quartz grains on Georges Bank and in other 

high-energy areas have iron oxide staining only in 

depressions in the grain surfaces, as if the entire 

grain had been subaerially stained during the 

Pleistocene emergence, and the staining since had 

been abraded from all but the depressions. 

Very little iron staining is found in a triangular 

area southeast, south, and southwest from the 

vicinity of Nantucket. The demarcation between 

areas of highly stained and of relatively nonstained 

grains is sharp southwestward from Martha's Vineyard nearly to the limit of the mapped area. The 

demarcation was also noted by Stetson (1938, p. 14) 

due south of Martha's Vineyard. In the area south 

of Long Island the demarcation is very close to the 

60-meter depth contour. In the triangular area of 

relatively nonstained grains, the entire sediment is 

dark green and has more organic matter (Jobst 

Hulsemann, oral commun., 1967) and more silt- and 

clay-sized particles (fig. 2) than the yellowish ironstained zone to the northwest. The nonstained area 

corresponds fairly well in extent with the area of 

smooth bottom shown on Garrison and McMaster's 

(1966, fig. 1) 1-fathom-contour map. The topography 

of the area with iron-stained grains, in contrast, is 

highly irregular on a small scale. It may be that the 

absence of iron staining results from deposition of 

a posttransgression sedimentary unit. Garrison and 

McMaster (1966) and McMaster and Garrison 

(1966) suggest the presence of such a unit in the 

area generally south of Martha's Vineyard. An 

alternate explanation of the relative lack of iron 

staining might be the similarity in the extent of the 

area in which quartz grains are only slightly stained 

(fig. 13C) and the area in which the shelf sediments 

include some silt! and clay (fig. 2). It seems possible 

that organisms that ingest sediment during feeding 

may have removed much of the iron staining originally present. In a profile south across the shelf 

from a point near Martha's Vineyard, Wigley and 

Mcintyre (1964, fig. 1, table 2) showed that the 

weight per unit area of macrobenthos is high in 

fine-grained shelf sediments, and that holothurians 

and other deposit feeders make up much of the 

macrobenthos. 

HIGHLY ROUNDED AND FROSTED GRAINS 

Distinctive highly rounded and frosted grains are 

common in continental shelf and slope sediments 

south and southeast of southern New England. They 

are also present in lesser amounts in the area of 

Browns Bank and in the northeastern part of 

Georges Bank. Alexander (1934), Stetson (1934), 

and Shepard and Cohee (1936) also noted them. 

Median diameter of the rounded grains is approximately 0.5 mm, and most range in size from 0.3 to 

1 mm. Roundness (in the sense of Krumbein, 1941) 

is generally 0.7 to 0.8, and sphericity (in the sense 

of Rittenhouse, 1943) averages 0.89. Figure 13D 

shows the areas in which the rounded grains exceed 

2 percent of the sand-size fraction of the sediment. 

The pattern shown is affected by the size of the 

sediment in which the rounded grains are found, 

because a slight admixture of the highly rounded 

grains in a sand of the same general size is difficult to identify. Highly rounded and frosted grains 

were found in nearly all shelf samples from south 

of New England and Long Island, as was also 

reported by Shepard and Cohee (1936). 

Size, roundness, and sphericity of the distinctive 

grains are relatively constant throughout the area 

in which they occur, but the sediments in which they 

are found range from coarse sands to silts. This 

indicates that the rounded grains were transported 

and deposited by a different mechanism than were 

the sediments in which they occur. The high roundness and well-developed frosting of the distinctive 

grains has no counterpart in the sediments that 

were transported-and deposited by glacial and water 

action, again indicating a different mechanism. 

Frosting of quartz is generally attributed to wind 

action (Pettijohn, 1957, p. 592; Shepard and Cohee, 

1936, p. 448). The frosting on the grains under 

discussion seems caused by abrasion rather than 

by solution, for it does not extend into depressions 

on the grain surfaces. The late glacial deposits on 

Cape Cod (Mather and others, 1940), Nantucket, 

Martha's Vineyard, and Long Island are rich in 

well-developed ventifacts. It seems highly probable 

that the distinctive highly rounded and frosted 

quartz grains were given their characteristics and 
K28 ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

were deposited where they are now found by strong 

periglacial winds of late Wisconsin time. 

SEDIMENT TYPES 

No standard classification scheme for mapping 

marine sediments is established, as it is for mapping 

rock units on land. Emery's (1952) classification 

has the virtue of being genetic, with the recognized 

limitation of including subjective interpretation, and 

is followed in this report. 

The classification is based on the dominant cause 

of deposition, and sediments of similar origin are 

mapped as units. Present-day detrital sediment is 

now being deposited in equilibrium with existing 

conditions. Relict sediment was deposited in the 

past as detrital sediments now are; but since its 

deposition the circumstances of waves, currents, 

and sea level have changed, and the sediment 

does not match present environmental conditions. 

Residual sediment is derived from rock units or 

prior unconsolidated deposits exposed on the sea 

floor, with little or no transportation involved. 

Organic sediments result from accumulation of tests, 

shells, skeletal debris, and the like. Authigenic sediments are chemically precipitated or altered minerals 

that have formed in the marine environment; the 

commonest are glauconite, phosphorite, maganese 

oxide, and pyrite. Sediments of other origins include 

ice-rafted gravels and volcanic deposits. Many sediments are mixtures resulting from several of these 

origins, but the product of one origin usually 

predominates. 

The topography and the composition of the sandsize fraction on selected traverses are shown in 

figure 14. Figure 15 shows the average composition 

and size distribution of the sand fraction in the 

areas discussed in the following sections, and figure 

16 shows the location of the areas and the distribution of Holocene and relict sediments. 

MODERN DETRITAL SEDIMENTS 

Non biogenic sediments now being deposited are 

originating from rivers, from shoreline erosion, from 

the shallow-water high-energy wave zone near shore, 

and from preexisting sediments now being eroded 

and transported by tidal currents. On the continental 

slope arid rise, sediments are now being deposited by 

settling of fine particles from the water. 

Protected Inshore Areas 

The intricate coastline of the area has numerous 

water bodies protected to some degree from the 

open sea. Most of the large rivers in the area discharge into such bodies of water, which serve as 

settling basins for the river-borne sediments: Thus 

sandy and clayey silt is being deposited in the 

deeper parts of most protected coastal water bodies. 

In the shallow parts and in constricted entrances, 

waves and tidal currents prevent deposition of the 

fine-grained river-borne detritus. The bottom in 

such areas is characteristically the bouldery lag 

deposit of winnowed till. 

Considering the coast from southwest to northeast Raritan Bay is floored with sandy silt and clay 

higher in dark minerals (7 percent of sand fraction) 

than protected coastal areas to the northeast. In 

agreement with the results of McCrone (1966a), 

most of the central area of Long Island Sound was 

found to be floored with sandy and clayey silts. They 

have as much as 6 percent mica and usually 2-3 

percent dark minerals in the sand fraction. At the 

eastern end of Long Island Sound, surface tidal 

currents have velocities as high as 5.2 knots (U.S. 

Coast and Geodetic Survey, 1947). This prevents 

deposition of fine sediment and has left exposed in 

some places a bouldery bottom that is a lag deposit 

derived from till, and in other places a poorly sorted 

silty and clayey sand. The later is a local product of 

slightly reworked glacial material, indicated by the 

freshness and angularity of its grains and its content of a few percent each of such labile components 

as rock fragments and mica. 

Sandy and clayey silt is also accumulating in Narrangansett Bay. It is derived from glacial material 

both by coastal and bottom-current erosion and by 

stream erosion and transport. The sand-size fraction 

has as much as 8 percent rock fragments, 2-3 percent dark minerals, and as much as 5 percent mica. 

For further information on the sediments of N arragansett Bay, see McMaster (1960, 1962). Silt 

and clay derived from glacial material is accumulating in the deeper central _parts of Buzzards Bay 

(Hough, 1940; Moore, 1963) and Cape Cod Bay 

(Hough, 1942). Sands and rocky lag deposits of 

glacial drift are common in the shallower areas, and, 

in Buzzards Bay, near entrances where currents are 

strong. The sand-size fraction of Cape Cod Bay 

sediment is more mature than that of most neighboring protected water bodies; rock fragments, dark 

minerals, and mica rarely exceed 1 percent. This 

is because no major rivers discharge into the bay, 

because the bay is more open to the sea than most 

other protected water bodies, and probably because 

the source glacial material includes much outwash 

sand with an earlier history of water transport. 
SAND-SIZE FRACTION OF BOTTOM SED! MENTS, NEW JERSEY TO NOV A SCOTIA K29 

The protected bays and passages of the coast of 

Maine are accumulating silty clay probably derived 

from river sediment and from marine erosion of 

glacial debris. The sand-size fraction, which makes 

up less than 10 weight percent of the sediment, 

consists characteristically of few or no rock fragments, 1-4 percent mica, and 2-3 percent dark 

minerals, in addition to quartz and feldspar, and a 

variable but small percentage of shell fragments. 

Nearshore Beach-Sand Zone 

The extreme inner shelf off sandy beaches is 

floored with relatively clean and mature quartzose 

sand similar to or identical with that on the adjoining beaches. These sand deposits are of Holocene 

or immediately pre-Holocene age. Off New Jersey 

the zone of beachlike sand extends roughly 5 km 

seaward, to a water depth of about 20 m. Near the 

northern end of the New Jersey coast, a sample of 

beach sand contains 15 percent glauconite, and two 

samples from less than 3 km offshore contain 25 

and 35 percent glauconite in their sand-size fraction. 

A number of highly glauconitic formations strike 

seaward in that area. South of Long Island the zone 

of beachlike sand also seems to extend to a water 

depth of about 20 m. Except for the glauconite area, 

constituents other than quartz and feldspar rarely 

exceed 1-2 percent in those areas. 

The sandy beaches of New Jersey and Long Island 

are each about 185 km long. The sandy beaches of 

the east side of Cape Cod and of the northern Massachusetts, New Hampshire, and extreme southern 

Maine coasts are each roughly 75 km long. Northeastward from Cape Elizabeth in southern Maine 

are found only short and pocket beaches as much as 

a few kilometers long. This progressive shortening 

is accompanied by an overall decrease in the maturity 

of the beach sediment, marked by a general increase 

in angularity of grains and in content of rock fragments, feldspar, shell fragments, and mica. The 

distance offshore to which beachlike sand is found 

also decreases progressively northeastward. 

Western Gulf of Maine 

Holocene sediment probably derived from both 

rivers and erosion of glacial deposits occupies a 

coastal belt roughly 50 km wide from Cape Cod to 

northern Maine. Except in areas adjacent to sandy 

beaches of southern Maine, New Hampshire, and 

parts of Massachusetts, the material is predominantly of silt size but includes considerable clay. 

It floors a chain of small nearshore topographic 

basins (fig. 1), and over much of its extent, particularly off the Maine coast, it is being deposited 

in small topographic depressions in a rough terrain 

of bouldery lag concentrate of glacial material and, 

at least in the very nearshore area, of bedrock 

ledges. 

The sand-size fraction of this sediment contains 

on the average 3 percent mica, 2 percent dark minerals, and 1 percent or less of rock fragments. 

Basins on the Continental Shelf 

Sediments of the numerous basins in the Gulf 

of Maine and the Roseway Basin on the Nova. Scotian 

shelf are predominantly silts and clays. Much of the 

volume of sediment in the basins probably originated 

from reworking of glacial deposits during and since 

the last transgression, but probably the surface 

material is derived at least in part, and perhaps 

entirely, from rivers and coastal erosion. Both the 

percentage of sand-size particles and the nature of 

the sand-size fraction show a broad range. 

The Wilkinson-Murray Basin northeast of Cape 

Cod has the finest sediments (median diameters in 

the clay-size range) and the smallest percentage of 

particles of sand size (0-2 percent over large areas) 

of any basin in the Gulf of Maine. It also has the 

most distinctive sand-size fraction; foraminiferan 

tests form as much as 80 percent of it; mica, as much 

as 15 percent; and sponge spicules, as much as 5 

percent. Th{l 2-3 percent of dark minerals is normal 

for much of the Gulf of Maine, but the quartzfeldspar content is so low (as little as 10-15 percent) 

that the ratio of dark minerals to quartz-feldspar 

is unusually high. Percentages of shell fragments 

range randomly from 0 to 7 percent. t 

Other basins have higher percentages of sandsize detrital grains, and those grains include more 

quartz-feldspar and rock fragments and less biogenic 

components. Basins and parts of basins where the 

sediment strongly shares the characteristics of the 

Wilkinson-Murray Basin include the Black, Rogers, 

and Lindenkohl Basins, the western part of the 

Jordan Basin, and a small part of the Georges Basin 

in the Gulf of Maine, and the Roseway Basin on the 

Nova Scotian shelf. These are the areas shown by 

the basin pattern in figure 16. Basins in which 

nearness to shore or velocity of currents has resulted 

in sediment more akin to till-derived material include the shallow basins near the Massachusetts, 

New Hampshire, and Maine coasts, the eastern part 

of the Jordan Basin, and most of the Georges Basin. 

Silt Deposit South of Martha's Vineyard 

Due south of Martha's Vineyard an area in which 

the sediment is predominantly of silt size extends 
11< 

/~ 

'oi ci><l'o 'orO 

7

0o r/f l7'"o 

0 100 200 300 MILES 

0 100 200 300 

KILOMETERS 

LOCATION OF TRAVERSES 

95 

90 

>--

z 

w 80 (.) 

0:: 

w 70 (1_ 

60 

50 

30 

l_~ __ L__L __ L_~-L--L---~~ 

EXPLANATION 

-

Glauconite 

Dark minerals 

Mill] 

Spicules and spines 

• Mica 

D 

Shell fragments 

Radiolaria 

~ 

LB Foraminifera 

Rock fr agments 

0 

Quartz and feldspar 

2000 

100 

95 

90 

80 

70 

60 

50 

30 

0 

~ 

"" 0 

> >--3 

t'" 

> z 

>--3 

...... 

0 

0 

0 

z 

>--3 

...... 

z 

t:rl 

z 

>--3 

> t'" 

w 

::r: 

t:rl 

t'" 

'"%j 

> z 

t::;j 

w 

t'" 

0 

'i:l 

t:rl 

0 

'"%j 

>--3 

::r: 

t:rl 

d 

z 

...... 

>--3 

t:rl 

t::;j 

w 

>--3 

> >--3 

t:rl 

w 
>--

z 

w 

u 

w "' 

Q_ 

>--

95 

90 

~ 80 

~ 70 

g: 60 

50 

30 

!00 

95 

90 

80 

70 

60 

50 

30 

0 

0 25 50 NAUTICAL MILES 

0 25 50 KILOMETERS 

VERTICAL EXAGGERATION X20 IN 

TOPOGRAPHIC PROFILES 

FIGURE 14.-Topography and composition of sand-size fraction on selected traverses. (Figure continued on following pages.) 

2000 

100 

95 

90 

80 

70 

60 

50 

30 

0 [ ' 

0 

500 

100 

95 

90 

80 

70 

60 

50 

30 

0 

r:n. 

> z 

tj 

rn. 

...... 

N 

tz:j 

"%j 

::0 

> l.l 

1-'3 

...... 

0 

z 

0 

"".l 

to 

0 

~ 0 

is: 

r:n. 

tz:j 

tj 

...... 

is: 

tz:j 

z 

1-'3 

r:n. 

z 

tz:j 

:a 

'-< 

tz:j 

::0 

r:n. 

tz:j 

>< 

""3 

0 

z 

0 

<! 

> 

r:n. 

l.l 

0 

:j 

> 

~ Cl:l 

~ 
0 

(/) 1000 0: 

w 

>-

w 

;;: 2000 

3000 

D 

100 

95 90 

>--

z 

w 80 u 

0: 

w 70 ()._ 60 

50 

30 

Wi lkinson-Mu r-ray Basin 

G eo

rg es Bank Bear 

D ' Sea mo u nt O 

-- 1000 

2000 

300 0 

100 

95 

90 80 

70 60 

50 30 

(/) 

"' w 0 

t;J 500 

;;: 100 ::::::::::::::::::::::::~====~~~~~~~~====::~~~~~~;;~~~~~~~~~li~~~;;~~~~~;r::~~~~ 100 500 

f"'.l.I'IWOIJJ 

1111111 '1 11! !.W'- ~ v 

9 5 ------=:v ~ ~ ![ilW 

90 

>--

z 

w 

80 u 70 a: 

w 

()._ 

60 

50 30 

0 

95 

90 

>--

z 

w 80 u 

"' 70 w 

CL 60 50 

30 

0 

-

0 

500 

100 

95 90 

80 

70 

60 

50 

30 

0 

95 

90 

80 

70 

60 

50 

30 

0 

~ <:,.:) 

t>:) 

> 

>-3 

t"" 

> z 

>-3 

...... 

("} 

("} 

0 

z 

>-3 

z 

t:z:j 

z 

>-3 

> t"" 

U1 

::II 

t:z:j 

t"" 

>:z:j 

> z 

t:::l 

U1 

t"" 

0 

"tt 

t:z:j 

0 

>:z:j 

>-3 

::II 

t:z:j 

q 

z 

...... 

>-3 

t:z:j 

t:::l 

U1 

>-3 

> >-3 

t:z:j 

U1 
E Nanllll"lcet tt N antucket E' Island 

'j &••"-' \] </) 1000 CY 

w 

fw 

::;: 2000 

Lung 

G /...;lola! Long G' I So11ud lt s landl 

!w,:j ::;roc 3000 

100 

95 

90 

fz 

w 80 u 

CY 

w 70 Q_ 60 

50 

30 

0 

F 0 

1000 

</) 

CY 

~ 2000 w 

::;: 

3000 

4000 

100 

95 ~ 

90 

fz 

u 80 u 

CY 

w 70 Q_ 60 

50 

30 

0 

Jjj!Ji . <..iJ.( 1111 I ~ v 1"\ j-llUli1 

~ 

0 

' 

N[[lll ~ 

1

1

vK 25 

0 25 

2000 2000 

100 ll llll lllll lltl1llllJJJIWilii 100 

,_ :~ ~~~~~ ~~~~ I I 

.................. 

l 

.. I .·C 

I 

H 

0 

11!!t!! ~ 1oo 

95 

90 

80 

70 

60 

50 

30 

~--_L----~---L----~--~----_L __ L_~--~ 0 

50 NAUTICAL MILES 

50 Kl LOM ETERS 

L __________ L---------~ 

VERTICAL EXAGGFRATION X20 IN 

TOPOGRAPHIC PROFILES 

FIGURE 14.--Topography and composition of sand-size fraction on selected traverses--Continued. 

'(J1 

> z 

tj 

in 

...... 

N 

i:.:rj 

":::j 

~ 

> 

(') 

>-3 

...... 

0 

z 

0 

":::j 

t:li 

0 

~ 0 

~ 

'(J1 

i:.:rj 

tj 

...... 

~ 

i:.:rj 

z 

>-3 

'(J1 

z 

i:.:rj 

~ 

<-< 

i:.:rj 

~ '(J1 

i:.:rj 

....:: 

>-3 

0 

z 

0 

< 

> 

'(J1 

(') 

0 

>-3 

;; 

~ ~ 

~ 
K34 

z 

0 

>= u 

~ "" 

0 

z 

"" (/) 

"-

0 

u.J 

"' "" >--

z 

u.J 

u 

"' u.J 

"-

0 

z 

"" (/) 

"-

0 

u.J 

"' "" fz 

u.J 

u 

"' u.J 

"-

ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

mm ~ 

";' ::!: :-;( f ' ' N ' ::!: ""- ~ 

TEED 50 

25 

0 

100 

90 

80 

70 

60 

50 

40 

30 

20 

10 

0 

Central and inner 

shelf south of 

Hudson Channel 

mm 

~ f :r f I 

~~n-iill 25U__Uj 

0 

90 

80 

70 

60 

50 

40 

30 

20 

10 

0 '---------'----'---"~-' 

Holocene sediment 

in Long Island 

Sound 

mm ~ 

::';:! ::;'. f ' ";' I 

N ...!. ::';:! ""- ::k 

[[ED 

-

~~ 

Central and inner 

shelf south of 

New England 

mm ~ 

::!: :-;( ~ 

' ' I ' N ::';:! ::k "' []EJ 

'Ill!!!!!! 

~ ~ 

Reworked glacial 

material, inshore 

southern New England 

mm ~ 

f :-;( 

";' f ' ::!: ::k ""- N 

[[EQ 

-~ 

~ t::::::,. 

Outer shelf 

south of 

New England 

mm ~ 

f :-;( :$!. 

I ' ' N ::!: :lit ::k 

DJJZJ 

S11 ! area on central 

>h If south of 

M:1rtha's Vineyard 

mm ~ 

::';:! :-;( 

I f I ' ...!. ::!: N ""- ~ 

ffiiJ 

Nearshore Holocene 

sed iment off 

New Jersey 

mm ~ 

- ::';:! :-;( :$!. 

' ...!. :k ' N ""- ::k 

m -

b---

Nantucket ShoalsStellwagen Bank 

mm ~ 

::';:! ::;'. ~ 

I I ' ' N ...!. ::!: ""- ~ 

~ 1"""'11111 

1\ 

Nearshore Holocene 

sediment south 

of Long Island 

mm ~ 

::!: ::;'. f I ' ' ' N ::!: ""- :$!. 

CIEJ 

j"l'l! 

t::::::-.. 

Georges Bank 

FIGURE 15.-Average composition and size distribution of surface sediment in individual 

areas. In each diagram the upper rectangle shows the particle-size distribution, 
SAND-SIZE FRACTION OF BOTTOM SEDIMENTS, NEW JERSEY TO NOVA SCOTIA 

z 

0 

>= '-' 

< 

Ct: 

.... 

Cl 

z 

< en 

.... 

0 

UJ 

"' < 

>--

z 

UJ 

'-' 

Ct: 

UJ 

"-

mm <0 

$ :;1!. f ' 

' ' :Je "' ..!. $ ;$!. 

"[[]]2J 50 

25 

0 

100 

90 

80 

70 

60 

50 

40 

30 

20 

10 

0 

10 

r---

--

Nearshore Holocene 

sediment in 

Gulf of Maine 

mm 

a~_.....--=,...~_, 

Continental shelf 

bordering 

Nova Scotia 

Dark 

minerals 

Glauconite 

rnrn <0 

$ :;1!. f ' I' ' ' ..!. $ ;$!. ;!!!. "' 

[I±TI 

\ 

' "' 

1\ r----. 

Gulf of Maine 

reworked glacial 

material 

mm 

f :;1!. f ' $ ;$!. 

Outer Northeast 

channel and tips 

of adjacent banks 

Foraminifera 

<0 

' 

:Je 

Mica 

mrn <0 

f :;1!. f I' ' $ ;$!. :Je "' OJIJ 

Gulf of Maine basins 

including Roseway Basin 

off Nova Scotia 

mrn <0 

$ :;1!. ;!!!. 

' ' ' :Je "' ..!. $ ;$!. 

---....::: c-... 

-

;--

Continental slope 

south of New England 

and Georges Bank 

EXPLANATION 

Quartz 

and 

feldspar 

Shell 

mm <0 

f :;1!. f I' ' $ ;$!. :Je "' []]1] 

P'" 

t'----~ 

Winnowed sand 

northwest of 

Georges Bank 

mrn <0 

$ :;1!. f ' ' ..!. $ ;$!. :Je "' 

-

i\ 

'~ 

Continental slope 

off southern 

Nova Scotia 

Rock 

fragments fragments 

the middle rectangle shows the composition of the sand-size fraction, and the circle 

shows the composition of the entire sediment. See figure 16 for location of areas. 

mm <0 

$ :;1!. ;!!!. ' ' ' ' ..!. $ ;o;t ;!!!. "' [JI[j ~"""""' 

~ 

Less 

than 

1/16 mm 

1\ ......___ 

Winnowed sand 

southwest of 

Nova Scotian shelf 

rnm 

Continental rise 

More 

than 

2mm 

K35 
K36 ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

from the middle of the continental shelf to near its 

outer edge. The origin of this sediment is unknown. 

Shepard and Cohee (1936, p. 454) noted that it is 

"impossible to be sure that this introduction of silt 

has been going on in recent times." Stetson ( 1938, 

p. 38-39) thought that "deposition of silts and clays 

is occurring on the central portion of the shelf***." 

McMaster and Garrison (1966, p. 1141) concluded 

that "the origin ***remains in doubt although it is 

firmly believed that [the silt deposit] accumulated 

in a topographic sag or warp in the shelf surface 

during the Holocene transgression." Garrison and 

McMaster (1966, p. 286) give evidence that the silt 

roi "'<l'. ro<O "'o. ri "'""· 0 100 200 300 MILES 

0 100 200 300 KILOMETERS 

CONTOURS IN METERS 

EXPLANATION 

D 

Holocene sediment 

1. Protected inshore areas 

2. N P.nrshore Holocene sand 

3. Western Gulf of Maine 

4. Basins on the continental shelf 

5. Silt area south of Martha's 

Vineyard 

6. Continental slope 

7. Continental rise 

Relict sediment 

8. Nonglaciated shelf south of 

New England 

9. Glaciated shelf south of New 

England 

10. N antucket Shoals-Nantucket 

Sound-Stell w agen Bank 

area 

11. Georges Bank and Great South 

Channel 

12. Floor of the Central Gulf of 

Maine 

13. Zones of winnowed sand 

14. Continental shelf near Nova 

Scotia 

15. Northeast Channel and tipe of 

adjacent banks 

FIGURE 16.-Areas of major sediment types and of Holocene 

and relict sediments. Areas in left column have Holocene 

sediments; areas in right column have relict. 

deposit is relict and that it was deposited rather late 

in the Holocene transgression. 

The composition of the sand-size fraction of the 

silt deposit differs distinctly from that of the shelf 

sediments adjacent to the west and less strongly from 

those adjacent ·on the east and north. In the silt 

area, the sand fraction contains less than 1 percent 

dark minerals and no rock fragments, whereas the 

sediment on the west contains 1-2 percent dark 

minerals and from trace amounts to 4 percent rock 

fragments. The silt area contains 2-3 percent of 

both detrital glauconite and mica in its sand-size 

fraction, but most of the adjacent shelf sediments 

to the west contains less than 1 percent of each. 

Relatively high percentages of dark minerals and 

rock fragments typify glacially derived material in 

this area, and an increase in the content of detrital 

glauconite indicates an origin involving the sedimentary rocks that underlie the shelf. The relatively 

low content of dark minerals and rock fragments 

and the relatively high content of detrital glauconite 

in the silt area at least suggest that it is more 

strongly related in origin to the underlying sedimentary rocks than to glacial material. McMaster and 

Garrison (1966, p. 1140) also suggest that the silt 

may be derived from an underlying Tertiary bed. 

As Garrison and McMaster (1966, p. 286) point 

out, the area of silt has a smooth surface, and it 

apparently lacks terraces. The sediment is not typical of that left by a transgressing shoreline, for 

it is not well sorted (Stetson, 1938, fig. 3) and the 

content of sand-size grains averages only about 15 

percent (John Schlee, oral commun., 1967). It thus 

was probably deposited after the last marine transgression. The depth at the shoreward side of the 

silt area is about 60 m. According to Shepard's 

(1963) curve, sea level was 60 m lower about 13,000 

years ago. Presumably that is the upper possible 

age limit of the silt deposit. Whether the silt is now 

being deposited remains unknown, but it seems 

possible that it is being winnowed from glacial 

sediments of the Nantucket Shoals area. This concept is strengthened by the observation that material 

of lOp. median diameter is in transport past a wellsorted sand bottom south of Martha's Vineyard 

(Raymond and Stetson, 1931; Stetson, 1938, p. 30). 

Continental Slope 

The sand-size fraction of continental slope sediments is enriched in the components of shelf sediments that are scarce in the high-energy zone of 

relatively clean quartzose sand that occupies the 

extreme outer shelf. Those components are primarily 
SAND-SIZE FRACTION OF BOTTOM SEDIMENTS, NEW JERSEY TO NOVA SCOTIA K37 

glauconite, mica, and dark minerals. (See fig. 14, 

C-F.) Slope sediments are impoverished in rock 

fragments compared with shelf sediments. This is a 

function of the decrease in particle size of slope 

sediments; reduced below the grain size of the 

constituent minerals, rock fragments become mineral 

grains. 

Seaward of Georges and Browns Banks, the sandsize fraction of slope sediments differs from that 

south of New England. The percentage of quartzfeldspar grains decreases and the percentage of 

foraminiferan tests increases at the rate of 2.5 

percent per 100-meter depth increase on the continental slope south of New England. On the slope 

seaward of the banks the rate is only 1.5 percent 

per 100 m. The slope sediments off the banks are 

lower in mica and in biogenic components and higher 

in rock fragments and quartz-feldspar than the 

"normal" slope sediments south of New England. 

The effect off the banks is of a seaward flushing of 

detrital components that tend to remain on the shelf 

in a "normal" area. This flushing probably has 

occurred in the banks area because it is near the 

outer edge of the continental shelf and tidal velocities across the banks are high. 

Slope sediments off Northeast Channel are much 

richer in rock fragments and dark minerals and are 

lower in quartz-feldspar and Foraminifera than 

slope sediments off the banks. The sediments off 

the channel are closely akin to the glacially derived 

sediments that floor much of the northern Gulf of 

Maine. They lack evidence of exposure to the highenergy environment of the banks. They must have 

been winnowed from glacial deposits in the channel 

itself or have been carried through the channel from 

the floor of the Gulf of Maine. The junction between 

continental rise and continental slope is at depths 

of 1,000-1,200 m seaward of Browns Bank and 

Northeast Channel, but is at 2,000 m seaward of 

Georges Bank, indicating that a great volume of sediment has been deposited on the rise off Browns Bank 

and the Northeast Channel (Uchupi, 1966, p. 3027). 

Continental Rise 

Continental rise sediments in the mapped area 

are formed predominantly of detrital silt and clay 

particles derived from the continent, but the sandsize fraction is mostly biogenic in origin. The median 

diameter of the entire sediment below depths of 

1,000-2,000 m is in the clay-sized range over most 

of the area. Sand-size material makes up less than 

10 percent of most samples, though exceptions are 

numerous. The calcium carbonate content of the rise 

sediments does not exceed 40 percent within the 

mapped area (Hiilsemann, 1967, fig. 3). 

The sand-size fraction on most of the continental 

rise deeper than 2,500 m between Hudson Canyon 

and Georges Bank ·contains more than 90 percent 

Foraminifera, with volumetrically minor amounts of 

radiolarians, spicules, ostracodes, and diatoms, in 

decreasing order of abundance. Characteristically, 

the remainder includes 3-5 percent quartz, as much 

as 2 percent mica, and as much as 1 percent each of 

dark minerals and glauconite. 

Certain rise samples, however, contain only 15-

45 percent Foraminifera, but 53-82 percent quartz. 

(The location of the unusual samples can be seen 

in figure 6.) From 10 to 25 percent of the unusual 

samples is of sand size, but most samples from the 

same depth contain less than 2 percent sand. The 

material of the unusual samples is characteristic of 

the continental slope at depths less than 2,000 m, 

but it is found at depths as great as 4,000 m and 

at distances of 24-120 km from the slope~ Normal 

rise sediments intervene. Its localized occurrence 

suggests that the material probably was emplaced 

by mass transport from the continental slope. 

In the vicinity of Hudson Canyon, sediments of 

the upper rise are also anomalously high in quartz 

( 55-65 percent of sand fraction) and low in Foraminifera (30-40 percent of sand fraction). Too few 

samples are available to determine whether the area 

of quartz concentration is genetically related to the 

canyon, or is another area of the type described in 

the preceding paragraph. 

Seaward transport of sand-size detrital material 

has been most strongly developed off Northeast 

Channel. The sand fraction of two samples from 

depths of 1,934 and 2,474 m directly seaward of the 

channel averages 80 percent quartz and feldspar and 

17 percent rock fragments, dark minerals, and glauconite. Foraminifera and mica total only 3 percent, 

but southwest from Georges Bank they make up as 

much as 80-90 percent of the sand fraction at the 

same depth. Such high percentages of rock fragments and dark minerals are characteristic of the 

glacially derived sediments within the Gulf of Maine, 

but not of the high-energy highly quartzose sands 

of the banks that border Northeast Channel. The 

available cores from nearby areas indicate that a 

significant thickness of sediment has been deposited 

on the continental rise since the last glacial stage 

(C. D. Hollister, oral commun., 1967). It therefore 

appears possible that sediment from the Gulf of 

Maine has been transported through Northeast 

Channel in postglacial time. 
K38 ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

RELICT SEDIMENTS 

Nonglaciated Shelf South of New England 

Most of the continental shelf south of New England and Long Island and off northern New Jersey 

is covered by highly quartzose sand of relatively 

uniform composition. Most of this sand contains 

less than 1 percent rock fragments and less than 2 

percent dark minerals. The general area of the 

Hudson Channel and an area centered 50 km south 

of the eastern tip of Long Island are exceptional in 

that their sands have as much as 5 percent rock 

fragments and 4 percent dark minerals. Except for 

two areas of high concentration near Long Island, 

the glauconite content of the sand ranges from trace 

amounts to 2 percent. In general, the concentration 

of detrital glauconite is slightly higher and the concentration of rock fragments and dark minerals is 

slightly lower in the eastern part of the area than 

in the western. This indicates that the sediment in 

the eastern part of the area may include a greater 

proportion of material derived from the sedimentary 

rocks that underlie the continental shelf than the 

western part. 

Foraminifera are sparse or lacking on the inner 

shelf and make up less than 1 percent of the sand 

over most of the outer shelf. At depths greater than 

about 120m, they make up 1-2 percent of the sand, 

and their concentration increases sharply at greater 

depths. The maximum percentages of foraminiferan 

tests in the sand-size range near the outer edge of 

the shelf in this area are 10 percent at a depth of 

139 m and 20 percent at a depth of 235 m. Most of 

the shelf sands contain less than 1 percent of mica 

and of shell fragments, although the latter make 

up as much as 5 percent of the sand-size fraction on 

the gravelly area south of Hudson Channel. 

These shelf sands are considered to be relict 

because they are coarser than sediment now originating from the nearby land, because submerged 

terraces marking former shorelines are preserved 

(Veatch and Smith, 1939; Ewing and others, 1963; 

Garrison and McMaster, 1966), and because they 

contain pre-Holocene oyster shells (Merrill and 

others, 1965). Iron staining on the surface of quartz 

grains, common in this area, is also a diagnostic 

property of relict sediments (Emery, 1968). These 

shelf sediments appear to have been originally deposited as glacial outwash during glacial periods, 

and to have been only slightly reworked by the transgression of the shoreline after the last glaciation. 

Gravel on the inner shelf south of Hudson Channel 

is similarly thought by Schlee (1964) to have been 

deposited by rivers during regression. Clay on the 

extreme outer shelf near Hudson Canyon was reported by Ewing, Le Pichon, and Ewing (1963, p. 

6314) to have been deposited by the Hudson River 

when the shelf was subaerial. 

Glaciated Nearshore Shelf South of New England 

The extreme inner shelf off southern New England 

is floored by sediment derived primarily from the 

underlying glacial deposits, probably mostly till. In 

restricted passages, as at the eastern end of Long 

Island Sound, tidal currents have eroded the finer 

material from the till and left a bouldery lag deposit. 

The less constricted inner shelf between Long Island 

and Martha's Vineyard is covered mostly by relict 

clean, well-sorted sand (McMaster, 1960, p. 273). 

It contains on the average 2 percent each of rock 

fragments and of dark minerals. It shares the characteristics and probably the origin of the sand on 

the adjacent seaward shelf, except that gravel remaining from reworking of glacial material is widespread (McMaster, 1960, fig. 13; Northrop, 1951, 

fig. 1). 

According to McMaster (1960, 1962), small areas 

of Holocene sediment of silt and sand size are now 

developing on the shelf near Narragansett Bay and 

Block Island. The situation is similar to that in the 

western Gulf of Maine, where fine-grained sediment 

is being deposited on reworked glacial deposits. 

Georges Bank, Nantucket Shoals, Great South Channel 

The predominantly sandy sediments of central 

Georges Bank, Nantucket Shoals, Nantucket Sound, 

and Stellwagen Bank are highly quartzose and occupy areas of high energy. The sediment in those 

areas probably is primarily of glacial origin and 

is therefore relict, but reworking during transgression and, in some areas, under present conditions is 

largely responsible for its present characteristics. 

Stewart and Jordan (1964) found that ridges of 

coarse sand on Georges Shoal, one of the shallowest 

areas on Georges Bank, have moved as much as 

300 m westward between two surveys 25-28 years 

apart, and that when the rotary tidal currents were 

normal to the ridges, the sand on the entire crest is 

in violent sheet flow. Jordan (1962, p. 848) found 

evidence on Georges Bank that sediment is in motion 

in water depths at least as great as 36 m. 

On the basis of available samples, most sandy 

sediment and the most mature sands on Georges 

Bank are not found on the shallowest part of the 

banks, where, presumably, conditions of highest 

energy exist, but instead are to the southeast. Considerable gravel and sandy gravel is found at the 
SAND-SIZE FRACTION OF BOTTOM SEDIMENTS, NEW JERSEY TO NOVA SCOTIA K39 

northeastern end of the shallow part of the bank, in 

depths of 33-56 m (Wigley, 1961, stations 91 and 

93-95; John Schlee, oral commun., 1967). This suggests that the high-energy processes of the shallow 

area of the bank may be acting on and modifying 

sediment that is not fully mature, and that the net 

southeastward movement detected by Jordan (1962, 

p. 846, fig. 7) in the Georges Shoal area may be 

responsible for moving the rounded, highly quartzose 

sand that originates on the shallow part of the bank 

southeastward into deeper water. The limits of the 

area ·within which sand is being transported on 

Georges Bank are not known. 

The sands of south-central Georges Bank are the 

cleanest and most quartzose sands in the mapped 

area, other than those on some present-day beaches. 

Over large areas all components of the sand fraction other than quartz and a subsidiary amount of 

feldspar total less than 1 percent, and quartz grains 

are rounded, frosted, and very little iron stained 

(fig. 13). This area of very high energy sands extends southeastward to about the 100-meter depth 

contour, nearly to the shelf edge. 

However, the sediment of the shallowest part of 

Georges Bank can hardly be considered immature. 

Mica and Foraminifera are almost totally lacking 

in the sand-size fraction, and less than 1 percent 

of rock fragments, dark minerals, and shell fragments is present over most of the area, though 

some samples contain as much as 2 percent rock 

fragments. Glauconite makes up 1-2 percent of the 

sand fraction in many places. 

On the deeper margins of Georges Bank, 1-3 

percent glauconite, as much as 2 percent shell fragments, and 1 percent dark minerals are the main 

components of the sand fraction other than quartz 

and feldspar. 

The sand on Nantucket Shoals and Stellwagen 

Bank and in Nantucket Sound is somewhat less 

quartzose than that on Georges Bank, but still it 

is typical of a high-energy environment. It averages 

3 percent shell fragments, 2 percent rock fragments, 

and 1 percent or less of dark minerals and glauconite. Slightly more iron staining is present on 

quartz grains (fig. 13C), and the quartz grains are 

slightly less well rounded (fig. 13A) than those on 

the shallow part of Georges Bank. 

The fact that the sand on Georges Bank is somewhat more mature than that on Nantucket Shoals 

and nearby areas may result in part from a greater 

admixture in the Georges Bank sand of second 

generation quartz grains derived from sedimentary 

rocks, rather than from any significant difference 

in postglacial history. 

Great South Channel southwest of Georges Bank 

is also underlain by relict material primarily of 

glacial origin; The sand fraction of the sediments 

of Great South Channel is akin to that on the 

periphery of Georges Bank, but the rock fragment 

content of 1-2 percent indicates a closer relation to 

the parent glacial material than is shown by much 

of the Georges Bank sediment. 

Floor of the Gulf of Maine 

Most of the central Gulf of Maine outside the 

basins is covered by a poorly sorted mixture of clay, 

silt, sand, and gravel. Its wide range of particle 

sizes, poor sorting, widespread occurrence, and composition indicate that it has originated primarily 

from till. It was probably exposed to little reworking 

by the transgressing sea that followed deglaciation, 

for a marine sedimentary unit now exposed subaerially in coastal Maine intertongues with deposits 

derived directly from glacial ice (Bloom, 1963). 

Thus marine conditions followed immediately after 

glacial withdrawal in areas now above sea level, 

and that was probably also true at lower elevations 

farther seaward. The poorly sorted till-derived sediment is obviously relict from earlier conditions because it differs so markedly from the silt and clay 

now being deposited in depressions floored by the 

till-derived material (Uchupi, 1966). The area the 

till-derived material occupies is highly irregular in 

topography. 

The glacial origin of this material is evident also 

in the composition of its sand-size fraction. Most 

samples have at least 1-5 percent rock fragments, 

the average being 10 percent and the maximum 35 

percent. Dark minerals make up 2-5 percent of the 

sand fraction of most samples, and the maximum is 

15 percent. Shell fragments are lacking in most 

samples, and usually less than 1 percent of mica and 

Foraminifera are present. As much as 1 percent of 

detrital glauconite occurs in nearly all samples south 

of an east-west line that lies between lat 43° and 

43 °30' ·N., and glauconite is lacking in nearly all 

samples north of that line. As previously noted, that 

line probably represents an approximation of the 

original landward extent of Teritiary and Cretaceous 

sedimentary rocks. Quartz grains are subangular 

and unfrosted and have a variable amount of iron 

staining. Iron staining increases near the Bay of 

Fundy, the source area of heavily stained grains 

from Triassic sedimentary rocks. 
K40 ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

Zones of Winnowed Sand 

Northwest of Georges Bank and southwest of the 

shallow shelf southwest of Nova Scotia are two areas 

of fine and very fine sand that has been winnowed 

and transported from the adjoining banks by current action. The sand is in depths generally between 

150 and 250 m. It is moderately well to well sorted 

and highly quartzose. The quartz grains are subangular and are heavily iron stained. 

Good sorting and small grain size indicate that 

the sand has been transported by water currents, 

and the adjoining banks- are the obvious sources. 

Current roses on navigation charts indicate that 

surface tidal currents exceed 2 knots southwest of 

Nova Scotia, and stronger currents are found on 

Georges Bank. However, evidence that this sand is 

now being transported is lacking, and it is very 

probably relict. 

The winnowed sand northwest of Georges Bank 

contains several percent of detrital-type glauconite 

(15 percent in one sample), and 1 percent or less of 

dark minerals. It is well sorted and is slightly better 

rounded than that southwest of Nova Scotia. These 

properties indicate that it was derived either directly 

or indirectly (through glacial action) from coastalplain sediments. The winnowed sand southwest of 

Nova Scotia includes more rock fragments and dark 

minerals but far less glauconite than the sand north-· 

west of Georges Bank, and it is more angular and 

not as well sorted. These properties indicate that it 

was derived largely from glacial material that 

originated in a crystalline terrane. 

Continental Shelf Near Nova Scotia 

The bottom sediment near Nova Scotia and seaward over Browns Bank to the shelf edge is_ basically similar to that on the floor of the central part 

of the Gulf of Maine. Both are poorly sorted mixtures of clay, silt, sand, and gravel, and both have 

originated from reworking of till. 

In the Nova Scotia-Browns Bank area, however, 

and particularly between southwestern Nova Scotia 

and the Maine coast, more gravel and boulders are 

present than in the central gulf, and the sand fraction contains more rock fragments and dark minerals. Mica makes up less than 1 percent of the sand 

fraction except in the vicinity of the Roseway Basin 

and in the immediate vicinity of Cape Sable, the 

southern tip of Nova Scotia. Glauconite is lacking 

on the inner shelf (except in the Bay of Fundy, an 

occurrence discussed in a preceding section), but 

an average of 1 percent is present on the outer shelf. 

As in the central Gulf of Maine, an east-west line 

between lat 43° and 43°30' N. is the boundary. 

Bottom photographs indicate that much of the 

area near Nova Scotia is armored with gravel and 

boulders. This fact and the presence of the winnowed sand zone to the southwe·st indicate that the 

sediments of the shelf in the Nova Scotia-Browns 

Bank area have been more extensively reworked 

than the sediment that floors the central Gulf of 

Maine. The relict aspect of the zone of winnowed 

sand indicates that most of the reworking occurred 

during or soon after the postglacial transgression. 

It is not known whether modern currents are affecting the bottom sediment in the Nova Scotia area. 

The available bottom photographs indicate that in 

general they are not, even though surface current 

maximum velocities average as high as 2.7 knots 

(U.S. Coast and Geodetic Survey, 1967, p. 138). 

Far more shell fragments and Foraminifera are 

present in the sand-size fraction in the Nova ScotiaBrowns Bank area than in the central Gulf of Maine. 

In the area southwest of Nova Scotia and northwestward to the Maine coast, the sand fraction 

contains from 3 to more than 60 percent shell fragments and 1-4 percent Foraminifera. Large areas. 

of Browns Bank and the nearby shelf have only 1-2 

percent shell fragments and less than 1 percent 

Foraminifera, however. The high biological productivity southwest of Nova Scotia is caused by the 

entrance of cold highly saline nutrient-rich water 

along the northeastern side of the Gulf of Maine and 

by vertical mixing of that water caused by tidal 

currents (Bigelow, 1928, p. 234, 247). 

The eastern and southern parts of Georges Basin 

and the inner part of Northeast Channel in general 

share the characteristics of the shallower shelf to 

the north. 

Northeast Channel and Tips of Adjacent Banks 

The sediments of the outer part of Northeast 

Channel and of the immediately adjacent parts of 

Georges and Browns Banks are predominantly 

gravel, sandy gravel, and gravelly sand (Wigley, 

1961, fig. 4). They are similar to those southwest of 

Nova Scotia in that their sand fractions contain 

high percentages not only of rock fragments and 

dark minerals but also of shell fragments and 

Foraminife·ra. 

The floor of Northeast Channel has as much as 

30 percent rock fragments and 2-3 percent dark 

minerals in its sand fraction. Those components indicate an origin from till. The sediment probably was 

deposited by glacial ice and has since been reworked, 

rather than transported into place after being deposited by ice, because much gravel is present, and 
SAND-SIZE FRACTION OF BOTTOM SEDIMENTS, NEW JERSEY TO NOVA SCOTIA K41 

it is probable that no mechanism since glaciation 

has been competent to move large and concentrated 

amounts of gravel. Torphy and Zeigler (1957) also 

concluded that Northeast Channel had been 

glaciated. 

The sediments of the outer part of Northeast 

Channel, and those of the tips of the adjoining banks, 

are characterized by high though locally variable 

percentages of shell fragments and Foraminifera. 

Two samples from the northeastern end of Georges 

Bank contain 35 and 80 percent shell fragments. On 

both the southern corner of Browns Bank and the 

floor of Northeast Channel, shell fragments range 

from less than 1 to 10 percent. Foraminifera, mostly 

benthonic types, make up 8-15 percent of the sand 

fraction on the northeastern end of Georges Bank, 

3-8 percent on the floor of Northeast Channel, and 

25-30 percent in a small area of the shelf on the 

north side of Northeast Channel in the angle where 

the trend of the channel intersects the northeastward 

trend of the shelf edge. These are the highest concentrations of Foraminifera found in the sand-size 

fraction on the continental shelf in the mapped area, 

excepting only the basins of the Gulf of Maine and 

the Nova Scotia shelf in which the sediment is 

predominantly of slit and clay size. The high organic 

productivity of outer Northeast Channel and adjacent parts of the bordering banks is probably related 

to the fact that the channel is the sole deep-water 

entrance to the entire Gulf of Maine-Bay of Fundy 

System. 

ORGANIC SEDIMENTS 

Shell fragments, foraminiferan tests, and other 

organic material do not form a dominant part of 

the bottom sediment anywhere in the area, except 

for a small number of isolated localities along the 

immediate coast and in the northeastern Gulf of 

Maine. Those localities are not mapped as organic 

in origin because the samples are probably from 

highly local concentrations of organic material. 

Foraminiferan tests and remains of other organisms dominate the sand-size fraction in some 

basins in the Gulf of Maine and over nearly all the 

continental rise, but in those areas all but a few 

percent of the bottom sediment is detrital silt and 

clay. 

AUTHIGENIC, RESIDUAL, AND RAFTED COMPONENTS 

The mapped area lacks bottom sediments known 

to be primarily authigenic or residual in origin. 

Authigenic components include glauconite along the 

outer shelf and upper slope, pyrite in some basins 

of the Gulf of Maine and on the slope and upper rise, 

and possibly limonite on the inner shelf south of 

New England, but none of those forms as much as 

1 percent of the sediment in those areas. 

The only major residual component that has been 

identified is detrital glauconite. In two small areas, 

one adjacent to the extreme northern coast of New 

Jersey, and the other 27 km southeast of the eastern 

tip of Long Island, glauconite makes up as much 

as 35 percent of the sand-size fraction, which in 

turn makes up 89 percent or more of the entire 

sediment. The evidence that this glauconite is probably residual, particularly in the latter area, is its 

relative lack of abrasion, its high but localized concentration, and the known or predictable proximity 

of highly glauconitic bedrock. 

The ring of glauconite concentrations around 

Georges Bank also indicates a residual component 

in the sediment there, derived from underlying 

coastal-plain sedimentary rocks, but like most nonauthigenic glauconite, it has probably been transported at least a short distance. 

Gravel and boulders on the continental shelf and 

slope beyond the probable limit of glacial moraine 

and outwash (Schlee and Pratt, 1970) indicate that 

ice-rafting has been an active agent of transportation in the area, but it is not at present. 

GEOLOGIC HISTORY 

Glaciation and the resulting regression and transgression of the shoreline are responsible for the 

present characteristics of most of the surficial shelf 

sediments in_ the area, including both glaciated and 

nonglaciated areas. The probable limit of glacial ice 

is shown in figure 1. 

The preglacial geology and topography of the 

continental shelf and the adjacent land controlled 

the type of sediment available to glacial and stream 

erosion, probably controlled the extent of glacial 

advance in at least the Georges Bank area, and in 

large measure determined the present topography. 

Before glaciation, the landward edge of the prism 

of coastal plain sedimentary rocks that underlies 

the continental shelf was at least as far landward 

as a line from Raritan Bay along the north shore 

of Long Island, through Buzzards Bay, across eastern Massachusetts, into the Gulf of Maine at least 

as far north as lat 42°11' N. (Chute, 1965), and 

eastward across the Gulf of Maine between lat 43° 

and 43 o 30' N. The Gulf of Maine existed as an inner 

lowland and Georges Bank as a cuesta. Northeast 

Channel probably carried the drainage from the 

Gulf of Maine (Uchpui, 1965b). The junction be-
K42 ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

tween the continental slope and rise off Northeast 

Channel, Browns Bank, and Nova Scotia was probably deeper and more strongly marked, as it now is 

south of New England. Whether the submarine 

canyons antedate glaciation is uncertain. 

Glaciation changed the topography by forming the 

terminal moraines that mark the present shoreline 

of much of eastern Long Island and southeastern 

New England. It reshaped the floors of the Gulf of 

Maine, Northeast Channel, and probably Great 

South Channel to approximately their present configuration. Stillstands of sea level caused terraces 

to form on the outer shelf south of New England 

and Long Island and east of New Jersey (Veatch 

and Smith, 1939; Ewing and others, 1963; Garrison 

and McMaster, 1966). The ice deposited a layer of 

till behind the line of maximum glacial advance 

in nearshore southern New England, apparently 

throughout the Gulf of Maine, and over the Nova 

Scotia shelf. Probably the ice terminated against 

the northwestern flanks of Georges Bank and outwash covered the bank. Outwash sands and perhaps 

also terminal or lateral moraines were deposited 

in the Nantucket Shoals area. Outwash sands and, 

off New Jersey, fluvial sand with some gravel 

blanketed the continental shelf seaward of the 

terminal moraine. The till and outwash material 

originated primarily from the crystalline bedrock 

of New England, Nova Scotia, and the glaciated 

area now covered by water. The till and outwash 

also includes material from. Triassic rocks of the 

Bay of Fundy area and from the coastal-plain sedimentary strata. During and probably also following 

glaciation, quantities of sediment were transported 

out Northeast Channel and over the Nova Scotia 

shelf and were deposited on the continental slope 

and upper rise. 

No effects directly attributable to glaciations before the Wisconsin have been noted in this study. 

During the transgression that followed the last 

glaciation, the outwash beyond the glacial ice limit 

and the till in the glaciated areas were reworked and 

were left in much their present condition. Winnowed 

sand transported landward from Georges Bank and 

the shallow shelf near southern Nova Scotia was 

deposited in two adjacent areas in the Gulf of 

Maine. Till on the Nova Scotia shelf, in Northeast 

Channel and the adjacent tip of Georges Bank, 

and in many areas of the Gulf of Maine was eroded 

to bouldery and gravelly lag deposits. Most of the 

fine-grained sediment in the basins of the Gulf of 

Maine and the Nova Scotia shelf probably originated 

by transgressive reworking of till. 

THE PRESENT REGIME 

At present most of the continental shelf appears 

to be neither receiving nor losing sediment. The 

relict sediments that floor most of it seem to have 

been little affected by other than biological action 

and slight currents since the postglacial transgression of the shoreline. This is true of most of the 

Gulf of Maine and nearly all of the Nova Scotia 

shelf and the shelf south of New England and Long 

Island and east of New Jersey. It is also true of 

most of Georges Bank, but high-energy conditions 

on the shallow parts of the bank have probably 

considerably altered the sediment there. Holocene 

sand is present and is subject to intermittent transportation along the parts of the coast that have 

developed as sandy beaches. An anomalous silt area 

on the middle and outer shelf south of Martha's 

Vineyard may represent the beginning of the accumulation of fine-grained shelf sediments that can 

be predicted for the future, barring further glacial 

stages. 

Sediment leaving the rivers is for the most part 

being deposited in protected nearshore areas, except 

for the rivers of eastern Massachusetts, New Hampshire, and southern Maine. Most of them discharge 

directly into the Gulf of Maine rather than into 

estuaries, bays, or sounds. Much of the small amount 

of sediment from them seems to be accumulating 

in a nearshore zone of small topographic basins. 

The surface of much of the Nova Scotian shelf, 

the outer part of Northeast Channel, and the northeastern tip of Georges Bank is in large part armored 

against further erosion by the gravelly and bouldery 

lag of glacial deposits. The detrital component of the 

slope and at least some of the extreme upper rise 

surficial sediments seaward of Georges and Browns 

Banks is far greater than that of the slope and rise 

deposits in the area southwestward from Georges 

Bank. These slope and rise sediments off the banks 

are probably relict, but it is notable that they are 

not deeply buried by normal hemipelagic sediment. 

REFERENCES 

Agassiz, Alexander, 1881, List of dredging stations occupied 

during the year 1880 by the U.S. Coast Survey steamer 

Blake, Commander J. R. Bartlett, U.S.N., Commanding: 

Harvard Univ. Mus. Comp. Zoology Bull., v. 8, p. 95-98. 

-- 1888, Three cruises of the United States Coast and 

Geodedetic Survey steamer Blake in the Gulf of Mexico, 

in the Caribbean Sea, and along the Atlantic Coast of 

the United States, from 1877 to 1880: Boston, Houghton, 

Mifflin & Co., 2 v. 

Alexander, A. E., 1934, A petrographic and petrologic study 

of some continental shelf sediments: Jour. Sed. Petrology, 

v. 4, no. 1, p. 12-22. 
SAND-SIZE FRACTION OF BOTTOM SEDIMENTS, NEW JERSEY TO NOVA SCOTIA K43 

Bailey, J. W., 1851, Microscopical examination of soundings 

made by the U.S. Coast Survey, off the Atlantic Coast 

of the United States: Smithsonian Contr. Knowledge, v. 

2, art. 3, 16 p. 

Bassler, R. S., 1936, Geology and paleontology of the Georges 

Bank canyons; part 3. Cretaceous bryozoan from Georges 

Bank: Geol. Soc. America Bull., v. 47, no. 3, p. 411-412. 

Bigelow, H. B., 1928, Exploration of the waters of the Gulf 

of Maine: Geog. Rev., v. 18, p. 232-260. 

Bloom, A. L., 1963, Late-Pleistocene fluctuations of sea level 

and postglacial crustal rebound in coastal Maine: Am. 

Jour. Sci., v. 261, no. 9, p. 862-879. 

Burbank, W. S., 1929, The petrology of the sediment of the 

Gulf of Maine and Bay of Fundy: U.S. Geol. Survey 

open-file report, 74 p. 

Burst, J. F., 1958, "Glauconite" pellets-their mineral nature 

and applications to stratigraphic interpretations: Am. 

Assoc. Petroleum Geologists Bull., v. 42, no. 2, p. 310-327. 

Chute, N. E., 1965, Geologic map of the Scituate quadrangle, 

Plymouth County, Massachusetts: U.S. Geol. Survey 

Geol. Quad. Map GQ-467. 

Colony, R. J., 1932, Source of the sands on the south shore 

of Long Island and the coast of New Jersey: Jour. Sed. 

Petrology, v. 2, no. 3, p. 150-159. 

Colton, J. B., Jr., 1964, History of oceanography in the offshore waters of the Gulf of Maine: U.S. Fish and Wildlife Service, Spec. Sci. Rept., Fisheries no. 496, 18 p. 

Cushman, J. A., 1936, Geology and paleontology of Georges 

Bank canyons; part 4. Cretaceous and Late Tertiary 

Foraminifera: Geol. Soc. America Bull., v. 47, no. 3, p. 

413-440. 

--- 1939, Eocene Foraminifera from submarine cores off 

the eastern coast of North America: Cushman Lab. 

Foram. Research Contr., v. 15, pt. 3, p. 49-76. 

--- 1944, Foraminifera from the shallow water of the 

northeast coast: Cushman Lab. Foram. Research, Spec. 

Pub. 12, 37 p. 

Dall, W. H., 1925, Tertiary fossils dredged off the northeastern coast of North America: Am. Jour. Sci., 5th ser., 

v. 10, p. 213-218. 

Ehlmann, A. J., Hulings, N. C., and Glover, E. D., 1963, 

Stages of glauconite formation in modern foraminiferal 

sediments: Jour. Sed. Petrology, v. 33, no. 1, p. 87-96. 

Emery, K. 0., 1952, Continental shelf sediments of southern 

California: Geol. Soc. America Bull., v. 63, no. 11, p. 

1105-1107. 

--- 1968, Relict sediments of continental shelves of the 

World: Am. Assoc. Petroleum Geologists Bull., v. 52, no. 

3, p. 445-464. 

Emery, K. 0., Merrill, A. S., and Trumbull, J. V. A., 1965, 

Geology and biology of the seafloor as deduced from 

simultaneous photographs and samples: Limnology and 

Oceanography, v. 10, no. 1, p. 1-21. 

Ewing, John, Le Pichon, Xavier, and Ewing, Maurice, 1963, 

Upper stratification of Hudson apron region: Jour. 

Geophys. Research, v. 68, no. 23, p. 6303-6316. 

Galliher, E. W., 1935, Glauconite genesis: Geol. Soc. America 

Bull., v. 46, no. 9, p. 1351-1366. 

Garrison, L. E., and McMaster, R. L., 1966, Sediments and 

geomorphology of the continental shelf off southern New 

England: Marine Geology, v. 4, no. 4, p. 273-289. 

Goddard, E. N ., chm., and others, 1948, Rock-color chart: 

Washington, Natl. Research Council, 6 p. (repub. by Geol. 

Soc. America, 1951). 

Goodell, H. G., 1966, Antarctic marine geology: Geotimes, 

v. 11, no. 4, p. 24-26. 

Hathaway, J. C., ed., 1966, Data file, Continental Margin 

Program, Atlantic coast of the United States, v. 1, 

Sample collection data: Woods Hole Oceanog. Inst. Reference No. 66-8, 184 p. 

--- 1967, Data file, Continental Margin Program, Atlantic 

coast of the United States, v. 1, Sample collection data, 

Supplement 1: Woods Hole Oceanog. In st. Reference 

No. 67-21, 108 p. 

Hazel, J. E., 1967, Classification and distribution of the 

Recent Hemicytheridae and Trachyleberididae ( Ostracoda) off northeastern North America: U.S. Geol. Survey 

Prof. Paper 564, 49 p. 

Holtedahl, Hans, 1958, Some remarks on geomorphology of 

continental shelves off Norway, Labrador, and southeast 

Alaska: Jour. Geology, v. 66, no. 4, p. 461-471. 

Hough, J. L., 1932, Suggestion regarding the origin of rockbottom areas in Massachusetts Bay: Jour. Sed. Petrology, 

v. 2, no. 2, p. 131-132. 

--- 1940, Sediments of Buzza1·ds Bay, Massachusetts: 

Jour. Sed. Petrology, v. 10, no. 1, p. 19-32. 

--- 1942, Sediments of Cape Cod Bay, Massachusetts: 

Jour. Sed. Petrology, v. 12, no. 1, p. 10-30. 

Hiilsemann, Jobst, 1967, The continental margin off the Atlantic Coast of the United States: Carbonate in sediments, Nova Scotia to Hudson Canyon: Sedimentology, 

v. 8, p. 121-145. 

Johnson, D. W., 1925, The New England-Acadian shoreline: 

New York, John Wiley & Sons, 608 p. 

Johnson, D. W., and Stolfus, M. A., 1924, The submerged 

coastal plain and old land of New England: Science, new 

ser., v. 59, no. 1526, p. 291-293. 

Jordan, J. F., 1962, Large submarine sand waves: Science, 

v. 136, no. 3519, p. 839-848. 

King, L. H., 1967, On the sediments and stratigraphy of the 

Scotian shelf in Geology of the Atlantic region: Geol. 

Assoc. Canada Spec. Paper 4, p. 71-92. 

Krinsley, David, Takahashi, Taro, Silberman, M. L., and 

Newman, W. S., 1964, Transportation of sand grains 

along the Atlantic shore of Long Island, New York: 

Marine Geology, v. 2, nos. 1-2, p. 100-120. 

Krumbein, W. C., 1941, Measurement and geological significance of shape and roundness of sedimentary particles: 

Jour. Sed. Petrology, v. 11, no. 2, p. 64-72. 

Light, M. A., 1952, Evidence of authigenic and detrital 

glauconite: Science, v. 115, no. 2977, p. 73-75. 

McCarthy, G. R., 1931, Coastal sands of the eastern United 

States: Am. Jour. Sci., 5th ser., v. 22, p. 35-50. 

McCrone, A. W., 1966a, Sediments from Long Island Sound 

(New York)-Physical and chemical properties reviewed: Jour. Sed. Petrology, v. 36, no. 1, p. 234-236. 

--- 1966b, The Hudson River estuary-hydrology, sediments, and pollution: Geog. Rev., v. 56, p. 175-189. 

McCrone, A. W., Ellis, B. F., and Charmatz, R., 1961, Preliminary observations on Long Island Sound sediments: 

New York Acad. Sci. Trans., ser. 2, v. 24, no. 2, p. 

119-129. 

McMaster, R. L., 1954, Petrography and genesis of the New 

Jersey beach sands: New Jersey Dept. Conserv. and 

Econ. Devel., Geol. Ser., Bull. 63, 239 p. 

--- 1960, Sediments of Narragansett Bay system and 
K44 ATLANTIC CONTINENTAL SHELF AND SLOPE OF THE UNITED STATES 

Rhode Island Sound, Rhode Island: Jour. Sed. Petrology, 

v. 30, no. 2, p. 249-274. 

---1962, Petrography and genesis of recent sediments in 

Narragansett Bay and Rhode Island Sound, Rhode Island: Jour. Sed. Petrology, v. 32, no. 3, p. 484-501. 

McMaster, R. L., and Garrison, L. E., 1966, Mineralogy and 

origin of southern New England shelf sediments: Jour. 

Sed. Petrology, v. 36, no. 4, p. 1131-1142. 

Marlowe, J. I., 1965, Probable Tertiary sediments from a 

submarine canyon off Nova Scotia: Marine Geology, v. 

3, no. 4, p. 263-268. 

Mather, K. F., Goldthwaite, R. P., and Thiesmeyer, L. R., 

1940, Preliminary report on the geology of western 

Cape Cod, Massachusetts: Massachusetts Dept. Publi<! 

Works Bull. 2, 53 p. 

Merrill, A. S., Emery, K. 0., and Rubin, Meyer, 1965, Ancient 

oyster shells on the Atlantic continental shelf: Science, 

v. 147, no. 3656, p. 398-400. 

Moore, J. R., III, 1963, Bottom sediment studies, Buzzards 

Bay, Massachusetts: Jour. Sed Petrology, v. 33, no. 3, 

p. 511-558. 

Murray, H. W., 1947, Topography of the Gulf of Maine, 

Field season of 1940: Geol. Soc. America Bull., v. 58; no. 

2, p. 153-196. 

Murray, John, 1885, Report on the specimens of bottom 

deposits: Harvard Univ. Mus. Comp. Zoology Bull., 

v. 12, p. 37-61. 

Northrop, John, 1951, Ocean-bottom photographs of the 

neritic and bathyal environment south of Cape Cod, 

Massachusetts: Geol. Soc. America Bull., v. 62, no. 12, 

p. 1381-1384. 

Northrop, John, and Heezen, B. C., 1951, An outcrop of 

Eocene sediment on the continental slope: Jour. Geology, 

v. 59, no. 4, p. 396-399. 

Oberkommando der Kriegsmarine, i943, Uboot handbuch der 

ostkiiste der V ereinigten S taa ten von N ordamerika, 

Nordlicher Teil (atlas) : Berlin, 124 charts. 

Owens, J. P., and Minard, J. P., 1960, Some characteristics of 

glauconite from the coastal plain formations of New 

Jersey in Geological Survey research 1960: U.S. Geol. 

Survey Prof. Paper 400-B, p. B430-B432. 

Parker, F. L., 1948, Foraminifera of the continental shelf 

from the Gulf of Maine to Maryland: Harvard Univ. 

Mus. Comp. Zoology Bull., v. 100, no. 2, p. 211-241. 

--- 1952a, Foraminifera species off Portsmouth, New 

Hampshire: Harvard Univ. Mus. Comp. Zoology Bull., 

v. 106, no. 9, p. 391-423. 

--- 1952b, Foraminiferal distribution in the Long IslandBuzzards Bay area: Harvard Univ. Mus. Comp. Zoology 

Bull., v. 106, no. 10, p. 428-473. 

Pettijohn, F. J., 1957, Sedimentary rocks (2d ed.): New 

York, Harper & Bros., 718 p. 

Phleger, F. B., 1952, Foraminifera ecology off Portsmouth, 

New Hampshire: Harvard Univ. Mus. Comp. Zoology 

Bull., v. 106, no. 8, p. 315-390. 

--- 1960, Ecology and distribution of Recent Foraminifera: Baltimore, Johns Hopkins Press, 297 p. 

Pourtales, L. F., 1870, Der Boden des Golfstromes und der 

Atlantischen Kiiste Nord-Americas: Petermann Mitt. 

aus Justus Perthes' Geographischer Anst., v. 16. p. 

393-398. 

--- 1872, The Gulf Stream; Characteristics of the Atlantic 

seabottom off the coast of the United States: Rept. of 

Superintendent, U.S. Coast Survey, for 1869, app. 11, p. 

220-225. 

Pratt, W. L., Jr., 1962', The origin and distribution of glauconite from the sea floor off California and Baja California: Univ. Southern California, Ph.D. dissert., 285 

p. Available from University Microfilms, Inc., Ann Arbor, 

Mich. 

Raymond, P. E., and Stetson, H. C., 1931, A new factor in 

the transportation and distribution of marine sediments: 

Science, new ser., v. 73, no. 1882, p. 105-106. 

Rittenhouse, Gordon, 1943, A visual method of estimating twodimensional sphericity: Jour. Sed. Petrology, v. 13, no. 

2, p. 79-81. 

Ross, D. A., 1967, Heavy-mineral assemblages in the nearshore surface sediments of the Gulf of Maine in Geological Survey research 1967: U.S. Geol. Survey Prof. Paper 

575-C, p. C77-:-C80. 

--- 1970, Atlantic continental shelf and slope of the 

United States-Heavy minerals of the continental margin, southern Nova Scotia to northern New Jersey: 

U.S. Geol. Survey Prof. Paper 529-G, 40 p. 

Sanders, H. L., 1956, The biology of marine bottom communities, in Oceanography of Long Island Sound, 1952-

1954: Bingham Oceanog. Colin. Bull., v. 15, p. 345-414. 

--- 1958, Benthic studies in Buzzards Bay. I. Animalsediment relationships: Limnology and Oceanography, 

v. 3, no. 3, p. 245-258. 

Schalk, Marshall, 1938, A textural study of the outer beach 

of Cape Cod, Mass.: Jour. Sed. Petrology, v. 8, no. 2, 

p. 41-54. 

Schlee, John, 1964, New Jersey offshore gravel deposit: Pit 

and Quarry Mag., v. 57, no. 6, p. 80, 81, 95. 

Schlee, John, and Cheetham, A. H., 1967, Rocks of Eocene 

age on Fipennies Ledge, Gulf of Maine: Geoi. Soc. 

America Bull., v. 78, no. 5, p. 681-684. 

Schlee, John, and Pratt, R. M., 1970, Atlantic continental 

shelf and slope of the United States-Gravels of the 

northeastern part: U.S. Geol. Survey Prof. Paper 529-H, 

39 p. 

Schlee, John, Uchupi, Elazar, and Trumbull, J. V. A., 1964, 

Statistical parameters of Cape Cod beach and eolian 

sands in Geological Survey research 1964: U.S. Geol. 

Survey Prof. Paper 501-D, p. D118-D122. 

Schopf, T. J. M., 1968, Atlantic continental shelf and slope 

of the United States-Nineteenth century exploration: 

U.S. Geol. Survey Prof. Paper 529-F, 12 p. 

Shepard, F. P., 1963, Thirty-five thousand years of sea level, 

in Essays in marine geology in honor of K. 0. Emery: 

Los Angeles, Calif., California Univ. Press, p. 1-10. 

Shepard, F. P., and Cohee, G. V., 1936, Continental shelf sediments off the mid-Atlantic states: Geol. Soc. America 

Bull., v. 47, no. 3, p. 441-457. 

Shepard, F. P., and Moore, D. G., 1954, Sedimentary environments differentiated by coarse-fraction studies: Am. 

Assoc. Petroleum Geologists Bull., v. 38, no. 8, p. 1792-

1802. 

Shepard, F. P., Trefethen, J. M., and Cohee, J. V., 1934, Origin 

of Georges Bank: Geol. Soc. America Bull., v. 45, no. 2, 

p. 281-302. 

Shrock, R. R., and Twenhofel, W. H., 1953, Principles of 

invertebrate paleontology (2d ed.): New York, McGrawHill Book Co., 816 p. 

Stephenson, L. W., 1936, Geology and paleontology of the 

Georges Bank canyons; part 2. Upper Cretaceous fossils 
SAND-SIZE FRACTION OF BOTTOM SEDIMENTS, NEW JERSEY TO NOVA SCOTIA K45 

from Georges Bank (including species from Banquereau, 

Nova Scotia): Geol. Soc. America Bull., v. 47, no. 3, p. 

367-410. 

Stetson, H. C., 1934, The origin and limits of a zone of 

rounded quartz sand off the southern New England 

coast: Jour. Sed. Petrology, v. 4, no. 3, p. 152-153. 

--- 1936, Geology and paleontology of the Georges Bank 

canyons; part 1. Geology: Geol. Soc. America Bull., v. 4 7, 

no. 3, p. 339-366. 

--- 1937, Current measurements in the Georges Bank 

canyons: Am. Geophys. Union Trans., 18th Ann. Mtg., 

July 1937, p. 216-219. 

--- 1938, The sediments of the continental shelf off the 

eastern coast of the United States: Massachusetts Inst. 

Technology and Woods Hole Oceanog. Inst., Papers in 

Physics, Oceanography, and Meteorology, v. 5, no. 4, 

48 p. 

--- 1939, Summary of sedimentary conditions on the continental shelf off the east coast of United States, in 

Trask, P. D., ed., Recent marine sediments, a symposium: 

Tulsa, Am. Assoc. Petroleum Geologists, p. 230-244. 

--- 1949, The sediments and stratigraphy of the east 

coast continental margin-Georges Bank to Norfolk 

Canyon : Massachusetts In st. Technology and Woods Hole 

Oceanog. Inst., Papers in Physics, Oceanography, and 

Meteorology, v. 11, no. 2, p. 1-60. 

Stetson, H. C., and Schalk, Marshall, 1935, Marine erosion 

of glacial deposits in Massachusetts Bay: Jour. Sed. 

Petrology, v. 5, no. 1, p. 40-51. 

Stewart, H. B., Jr., and Jordan, G. F., 1964, Underwater 

sand ridges on Georges Shoal, in Miller, R. L., ed., 

Papers in marine geology (F. P. Shepard commemorative volume): New York, Macmillan Co., p. 102-114. 

Suter, Russell, de Laguna, Wallace, Perh~utter, N. N., and 

Brashears, M. L., Jr., 1949, Mapping of geologic formations and aquifers of Long Island, New York: New 

York Water Power and Control Comm. Bull. GW-18, 

212 p. 

Tagg, A. R., and Uchupi, Elazar, 1966, Distribution and 

geologic structure of Triassic rocks in the Bay of Fundy 

and the northeastern part of the Gulf of Maine in 

Geological Survey research 1966: U.S. Geol. Survey Prof .. 

Paper 550-B, p. B95-B98. 

Taney, N. E., 1961a, Geomorphology of the south shore of 

Long Island, New York: U.S. Army Corps Engineers, 

Beach Erosion Board Tech. Memo. 128, 50 p. 

--- 1961b, Littoral materials of the south shore of Long 

Island, New York: U.S. Army Corps Engineers, Beach 

Erosion Board Tech. Memo. 129, 59 p. 

Terry, R. D., and Chilingar, G. V., 1955, Summary of "Concerning some additional aids in studying sedimentary 

formations," by M. S. Shvetsov: Jour. Sed.' Petrology, 

v. 25, no. 3, p. 229-234. 

Todd, Ruth, and Low, Doris, 1961, Near-shore Foraminifera 

of Martha's Vineyard island, Massachusetts: Cushman 

Found. Foram. Research Contr., v. 12, pt. 1, p. 5-21. 

Torphy, S. R., and Zeigler, J. M., 1957, Submarine topography 

of Eastern Channel, Gulf of Maine: Jour. Geology, v. 

65, no. 4, p. 433-441. 

Townsend, C. H., 1901, Dredging and other records of the 

U.S. Fish Commission steamer Albatross, with bibliography relative to the work of the vessel, in Report of 

the Commissioner for the year ending June 30, 1900: 

Washington, U.S. Comm. Fish and Fisheries, p. 387-562. 

Trowbridge, A. C., and Shepard, F. P., 1932, Sedimentation 

in Massachusetts Bay: Jour. Sed. Petrology, v. 2, no. 1, 

p. 3-37. 

U chupi, Elazar, 1965a, Map showing relation of land and 

submarine topography, Nova Scotia to Florida: U.S. 

Geol. Survey Misc. Geol. Inv. Map I-451, 3 sheets, scale 

1:1,000,000. 

--- 1965b, Basins of the Gulf of Maine in Geological 

Survey research 1965: U.S. Geol. Survey Prof. Paper 

525-D, p. D175-D177. 

--- 1966, Structural framework of the Gulf of Maine: 

Jour. Geophys. Research, v. 71, no. 12, p. 3013-3028. 

--- 1968, Atlantic continental shelf and slope of the 

United States-Physiography: U.S. Geol. Survey Prof. 

Paper 529-C, 30 p. 

Upham, Warren, 1894, The fishing banks between Cape Cod 

and Newfoundland: Am. Jour. Sci., 3d ser., v. 47, p. 

123-129. 

U.S. Coast and Geodetic Survey, 1947, Tidal current charts, 

Long Island Sound and Block Island Sound (3d ed.) : 

U.S. Coast and Geodetic Survey. 

--- 1967, Tidal current tables, Atlantic Coast of North 

America, 1968: U.S. Coast and Geodetic Survey, 200 p. 

(1968). 

U.S. Coast Survey, 1848, Report of the Superintendent of the 

Coast Survey, showing the progress of the work during 

the year ending October, 184 7: Washington, U.S. Govt. 

Printing Office, 88 p.; also Senate Ex. Doc. 6, U.S. 30th 

Cong., 1st sess., v. 3. 

U.S. Naval Oceanographic Office, 1965, Oceanographic atlas 

of the North Atlantic Ocean, Sec. V, Marine Geology: 

Washington, U.S. Naval Oceanog. Office, 71 p. 

Veatch, A. C., and Smith, P. A., 1939, Atlantic submarine 

valleys of the United States and the Congo submarine 

valley: Geol. Soc. America Spec. Paper 7, 101 p. 

Verrill, A. E., 1878, Occurrence of fossiliferous Tertiary 

rocks on the Grand Banks and Georges Bank: Am. Jour. 

Sci., 3d ser., v. 16, p. 323-324. 

Wigley, R. L., 1961, Bottom sediments of Georges Bank: 

Jour. Sed. Petrology, v. 31, no. 2, p. 165-188. 

Wigley, R. L., and Mcintyre, A. D., 1964, Some quantitative 

compar1sons of offshore meiobenthos and macrobenthos 

south of Martha's Vineyard: Limnology and Oceanography, v. 9, no. 4, p. 485-493. 

Zeigler, J. M., Tuttle, S. D., Tasha, H. J., and Giese, G. S., 

1964, Pleistocene geology of outer Cape Cod, Massachusetts: Geol. Soc. America Bull., v. 75, no. 8, p. 705-714. 

U. S. GOVERNMENT PRINTING OFFICE: 1972 0- 47!!-199