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UNITED STATES DEPARTMENT OF THE

GEOLOGY AND BIOLOGY 

NORTH ATLANTIC DEEP-SEA

PART 9. SELENIUM CONTENT AND CHEMICAL

INTERIOR

OF 

CORES

ANALYSES

GEOLOGICAL SURVEY PROFESSIONAL PAPER 196-F

UNITED STATES DEPARTMENT OF THE INTERIOR 

Harold L. Ickes, Secretary

GEOLOGICAL SURVEY 

W. C. Mendenhall, Director

Professional Paper 196-F

GEOLOGY AND BIOLOGY OF

NORTH ATLANTIC DEEP-SEA CORES

BETWEEN NEWFOUNDLAND AND IRELAND

PART 9. SELENIUM CONTENT AND CHEMICAL ANALYSES

i 

BY

GLEN EDGINGTON AND H. G. BYERS

UNITED STATES

GOVERNMENT PRINTING OFFICE 

WASHINGTON : 1942

For sale by the Superintendent of Documents, Washington, D. C. ....... . Price 15 cents

CONTENTS

Outline of the complete report______-________-_________________-_________-_____________--__-_-------_-------_-- v

Summary of the complete report____-___-____-___________^___________-____________-----------_-_--__-----_----_ vn

Foreword, by C. S. Piggot-____-_____--______-_________.._____________-____-_-___-___---__---_____---___--------- ' XJ

General introduction, by W. H. Bradley._______-__________-___________________-___-__----_--_-_--__----_--------- Xm

Significance of the investigation.____-____________________________________________--___-___--_--------__----- Xin

Location of the core stations.____-_______-___-__--____-______________-_______-__---------_---------------_-- Xiv

Personnel and composition of the report--__-________-___________-______--_-_-_-____--_-___---_---_----------- Xiv

Methods of sampling and examination______________________________________________________________________ Xiv

Part 9. Selenium content and chemical analyses, by Glen Edgington and H. G. Byers..__________________--__----_-_--- 151

Introduction._______.___________________________________________________•_________________________---_-____ * 151

Analytical procedure.______________________________________________________________________________________ 151

Analytical results._________________________________________________________________________________________ 152

Discussion of analyses.._______________________________________________-________-_-______--_-_--__-------_- 154

Selenium.________________________________________________________________________________________________ 155

Index.________________________________________________________________-____-___--_-___-_---_--_---_-_ xvn

ILLUSTRATIONS

PLATE 1. Bathymetric chart of a part of the North Atlantic Ocean showing the location of the core stations..___________ xv

2. Longitudinal sections of the air-dried cores._________________-___-____-_-_-____-_-_-_______--__---___-___ XV

FIGURE 1. Profile across 'the North Atlantic Ocean bottom along the line of the numbered core stations--________________ xiv

TABLES

TABLE 1. Geographic location, length of cores, and depth of the water from which they were taken._____________________ Xiv

34. Chlorine content of dry sample and chlorine lost by ignition______________________________________________ 152

35. Chemical analyses of sea-bottom cores_________________________________________________________________ 153

36. Silica-sesquioxide and silica-alumina ratios of sediments______-_____-________-_-_____--___-___--_.__-__-____ 154

ill

OUTLINE OF THE COMPLETE REPORT

Foreword, by C. S. Piggot.

General introduction, by W. H. Bradley.

PART 1. Lithology and geologic interpretations, by M. N. Bramlette and W. H. Bradley.

2. Foraminifera, by Joseph A. Cushman and Lloyd G. Henbest.

3. Diatomaceae, by Kenneth E. Lohman.

4. Ostracoda, by Willis L. Tressler.

5. Mollusca, byJHarald A, Rehder.

6. Echinodennata, by Austin H. Clark.

7. Miscellaneous fossils and significance of faunal distribution, by Lloyd G. Henbest.

8. Organic matter content, by Parker D. Trask, H. Whitman Patnode, Jesse LeRoy Stimson, and John R. Gay.

9. Selenium content and chemical analyses, by Glen Edgington and H. G. Byers.

SUMMARY OF THE REPORT

In May and June 1936 Dr. C. S. Piggot of the Geophysical 

Laboratory, Carnegie Institution of Washington, took a series 

of 11 deep-sea cores in the North Atlantic Ocean between the 

Newfoundland banks and the banks off the Irish coast. These 

cores were taken from the Western Union Telegraph Co.'s cable 

ship Lord Kehin with the explosive type of sounding device 

which Dr. Piggot designed. In the fall of that year he invited a 

group of geologists of the United States Geological Survey to 

study the cores and prepare a report. Biologists of the United 

States National Museum, the University of Buffalo, and chemists of the United States Department of Agriculture cooperated 

in the investigation and contributed to the report.

The westernmost core of the series (No. 3; was taken in the 

blue mud zone, but all the others were taken in parts of the ocean 

where the bottom is blanketed with globigerina ooze. The 

shortest cores are No. 8, taken on the mid-Atlantic ridge in 1,280 

meters of water, and No. 11, taken where the ccie bit struck 

volcanic rock. The cores range in length from 0.34 to 2.93 

meters and average 2.35 meters. They were taken at depths 

ranging from 1,280 to 4,820 meters.

Lithology and geologic interpretations.—In about 20 representative samples from each core the percentages of calcium carbonate, 

clay and silt, and. sand were determined and plotted, and the 

relative abundance of Foraminifera, coccoliths, and diatoms was 

estimated. Material between these guide samples was examined 

microscopically, especially in certain critical zones.

Two zones were noted in which silicic volcanic ash (refractive 

index near 1.51) is common. The upper ash zone was found in 

all the cores except No. 11, but the lower one was found only in 

the lower part of cores 4 to 7. In core 3 the upper ash zone is 

represented by shards scattered very sparsely all through the 

core, as this core, despite its length of 2.82 meters, apparently did 

not reach the bottom of the ash zone. The upper ash zone, 

together with other adjacent lithologic zones, serves to correlate 

the cores, and the lower ash zone, found west of the mid-Atlantic 

ridge, helps to confirm the correlation.

Besides the zones of volcanic ash four other zones distinctive in 

lithologic character were found. These zones are characterized 

by a relative abundance of sand and pebbles, by a smaller 

percentage of calcium carbonate, and by a sparsity of Foraminifera and coccoliths. They are distinctive also in texture. The 

pebbles are subrounded to angular and include a wide variety 

of rock types—sandstone, gneiss, soft shale, and limestone—of 

which limestone is the most common. Some of the pebbles are 

as much as 2 centimeters across. These zones are interpreted as 

glacial marine deposits formed during the Pleistocene glacial 

epoch, when continental glaciers were eroding the land. Drift 

ice from the continental glaciers apparently transported considerable quantities of rock debris far out into the ocean basin.

Between the glacial marine zones found in the North Atlantic 

cores the sediments consist chiefly of foraminiferal ooze or marl, 

much like that which is forming today in the same area.

The uppermost glacial marine zone is represented in all the 

cores except Nos. 3 and 11 and lies just below the upper volcanic 

ash zone. In cores 4 to 7 the glacial zones are relatively thin and 

are spaced at approximately equal intervals; between the third 

and fourth glacial zones (in descending order) is the lower volcanic 

ash. East of the mid-Atlantic ridge only the uppermost glacial

zone has been identified. Other glacial marine deposits are 

recognizable but their correlation is less certain.

Three interpretations are offered as possible explanations of 

the four glacial marine zones. The first is that each glacial 

marine zone represents a distinct glacial stage of the Pleistocene 

and that each zone of foraminiferal marl separating two glacial 

marine zones represents an interglacial stage. This interpretation seems least probable of the three. The second interpretation 

is that the upper two glacial marine zones and the intervening 

sediment may correspond to the bipartite Wisconsin stage, 

whereas the lower two represent distinct glacial stages of the 

Pleistocene separated from each other and from the zone representing the Wisconsin stage by sediments that represent interglacial epochs no greater in length than postglacial time. This 

interpretation seems to imply too short a time for most of the 

Pleistocene epoch. The third interpretation, which is favored 

by the authors, is that each of the four glacial marine zones 

represents only a substage of the Wisconsin stage. This implies 

that the North Atlantic at approximately 50° north latitude for 

comparatively long periods of time alternately contained an 

abundance of drift ice and then was quite, or nearly free of ice, 

while on land a continental ice sheet persisted, though it alternately waned and grew:

In the four cores in which the postglacial sediments are 

thickest the pelagic Foraminifera, according to Cushman and" 

Henbest, reveal an interesting condition. These organisms 

indicate that during the middle part of the postglacial interval 

the temperature of the surface water in that part of the North 

Atlantic was somewhat higher than prevails today.

On the assumptions that the top of the uppermost glacial 

marine zone represents the beginning of the postglacial epoch as 

defined by Antevs, and that this was probably as much as 9,000 

years ago, the postglacial sediment in these cores accumulated 

at a rate of about 1 centimeter in 265 years; but, because the sea 

probably cleared of detritus-laden drift ice long before the land 

in the same latitude was cleared of the retreating continental 

ice sheet, the average rate of accumulation may have been as 

low as 1 centimeter in 500 years.

Coarse-grained sediment on the tops of ridges and fine-grained 

sediment in the deeper basins indicate that currents move across 

these ridges with sufficient velocity to winnow out the finer 

particles and sweep them into deeper basins beyond.

The fact that the glass shards in the volcanic ash zones have 

been reworked and distributed without any gradation in size 

through many centimeters of the overlying sediments leads us 

to believe that mud-feeding animals are continually working over 

these shards and other particles of sand and silt so that they are 

redistributed at successively higher levels. The shards and other 

particles may also be reworked by gentle bottom currents that 

move the material from mounds and ridges on the sea floor and 

drift it about over the adjacent flatter areas.

Several layers in the cores are sharply set off by the coarser 

grain size of the sediment or by a regular gradation in grain size 

from coarsest at the base to fine at the top. These may be a 

result of submarine slumping.

The term globigerina ooze is used loosely in this report to 

designate sediment, half or more than half of which, by weight, 

consists of Foraminifera. This usage accords more closely with

VII
VIII SUMMARY OF THE REPORT

the usage adopted by Correns in the Meteor reports than with 

the usage of Murray and Chumley in the Challenger reports, 

which was based solely on the carbonate content. Limy muds 

containing a lesser but still conspicuous number of Foraminifera 

are referred to as foraminiferal marl. The carbonate content 

of the globigerina ooze in these cores ranges from 46.6 to 90.3 

percent and averages 68.2 percent. In 191 samples representing 

all the lithologic types, the carbonate content ranges from 10.0 

to 90.3 percent and averages 41.3 percent. Coccoliths are 

abundant in many parts of the cores, but by reason of their small 

size they rarely make up as much as 10 percent of the sediment 

Pteropods are rather numerous in parts of the cores taken on the 

mid-Atlantic ridge and on the continental slope off the Irish 

coast.

Most of the calcium carbonate in these sediments consists of 

the tests and comminuted fragments of calcareous organisms. 

The finest particles of carbonate are of indeterminate origin, but 

their irregular shape and range in size suggest that they are 

largely the finest debris of the comminuted organisms rather 

than a chemical precipitate. Clusters or rosettes of calcium 

carbonate crystals were found in many samples, but they are not 

abundant. They evidently formed in the mud on the sea floor.

No conclusive evidence of an increase in magnesium carbonate 

with depth was found, though some of the data suggest it. The 

magnesium carbonate is somewhat more abundant in the glacial 

marine zones than elsewhere, but its concentration in those zones 

is probably accounted for by the presence of clastic grains and 

pebbles of dolomite.

Diatom frustules, radiolarian skeletons, and sponge spicules 

are the most common siliceous organic remains found in the 

cores, and these generally form less than 1 percent of the sediment. One notable exception is the sediment in the middle part 

of core 9, just east of the mid-Atlantic ridge, which contains 50 

percent or1 more of diatoms.

Ellipsoidal and elongate or cylindrical pellets that appear to 

be fecal pellets are plentiful in the mud at the tops of cores 10 

and 12, taken in the eastern part of the North Atlantic, but 

were not found elsewhere. No attempt was made to identify 

them further.

The sand-size material showed no marked variation in the 

mineral composition of the clastic grains at different horizons 

within individual cores and no conspicuous lateral variation 

from core to core. The mineral grains in the sand-size portions 

were not separated into light and heavy fractions, but simple 

inspection showed that grains of the heavy minerals are somewhat more common in the glacial marine deposits than elsewhere. Well-rounded sand grains are sparsely scattered through 

all the cores, but they are rather more plentiful in the- glacial 

marine zones. These grains, which range in .diameter from about 

0.1 to 1.0 millimeter and average 0.5 millimeter, have more or 

less frosted surfaces. They may have been derived from the 

reworking of glacial marine deposits or they may have been 

rafted by seaweeds. Little was done with the clay minerals 

other than to note that most of them have the optical properties 

of the beidellite or hydrous mica groups.

Six samples were tested with a 10-inch spectograph, which 

revealed the presence of appreciable amounts of barium and 

somewhat less of boron in each sample. All the samples gave 

negative tests for antimony, beryllium, bismuth, cadmium, germanium, lead, silver, tin, and zinc.

The original porosity of several samples in core 3 was calculated from the porosity of the dried samples. The original 

porosity plotted against depth in the core seems to indicate that 

fine-grained blue muds buried to a depth of 2 or 3 meters in the 

ocean floor are appreciably compacted.

Partial mechanical analyses of nearly 200 samples were made 

and plotted, but only four complete mechanical analyses were

made. The complete analyses were made by the sedimentation 

method and include four distinctive types of sediment.

Pumiceous fragments and smaller shards of basaltic volcanic 

glass (index of refraction near 1.60) are scattered throughout all 

the cores, but are somewhat more common east of the mid-Atlantic ridge than west of it. Unlike the alkalic volcanic ash it 

shows no conspicuous concentration in zones. Most of the basaltic glass and pumice has a thin surface alteration film of palagonite. The films are thickest on fragments in cores taken from 

ridges where oxygen-bearing waters had free access to the sediments. Two varieties of palagonite are recognized.

Core 11 represents only 34 centimeters of the sea floor because 

the core bit encountered deeply altered olivine basalt. About 

15 centimeters of globigerina ooze rests on and within irregular 

cavities of the upper surface of a mass of clay that is apparently 

altered basalt. This clay is impregnated with manganese and 

contains nodular lumps of altered basalt. Part of the basalt 

near the base of the core is less altered. The clay contains scattered grains of sand and foraminiferal shells in which the original 

calcium carbonate has been replaced by a zeolite resembling phillipsite. This core may have penetrated the upper, deeply altered 

part of a submarine lava flow, but the evidence is not conclusive.

Core 10 contains two rather thick beds of distinctive clayey 

mud. About half of this mud is a beidellite or hydrous mica 

type of clay and the other half is made up of silt-size particles of 

basaltic glass, magnetite, augite, and calcic plagioclase. It 

contains very little common clastic material and exceedingly 

few Foraminifera. The composition and texture suggest that 

this mud was derived largely from a submarine volcanic eruption 

that threw into suspension clay particles perhaps partly from the 

normal sediment and from deeply altered basalt. A complete 

chemical analysis of this mud is given.

Foraminifera.—From these^ cores 184 samples representing 

every lithologic zone were examined for calcareous fossils. All 

but five samples contained Foraminifera. As in existing oceans 

deeper than several hundred meters, pelagic Foraminifera greatly 

outnumber the bottom-dwelling forms, though in variety of form 

and in number of genera and species the bottom forms greatly 

exceed the pelagic. Several zones of relatively pure globigerina 

ooze were found, and many in which the ooze was clayey or sandy. 

Though variations in temperature were reflected by faunal 

changes, the general bathymetric facies of the faunas appear to be. 

rather uniform throughout each core. The bottom faunas are 

least varied and prolific in cores from the deepest water, whereas 

in cores from the shallowest water they are by far the most 

varied and prolific. Cores from intermediate depths contain 

faunas of intermediate bathymetric facies. These relations to 

depth are, in general, characteristic also of faunas in the existing 

oceans. A few scattered specimens of Elphidium or Elphidiella 

were found. These genera thrive in shallow water, but in these 

cores the shells are so rare, so erratically distributed, and in some 

so poorly preserved that it seems probable they were rafted in by 

seaweeds or ice and therefore have no significance as indicators of 

depth. No species peculiar to the Miocene or Pliocene were 

found. It appears, therefore, that all the sediments penetrated 

by the cores are younger than Pliocene. Alternation of faunas 

that are characteristic of the warm and cold climates of the 

present day indicates great climatic changes during the time 

represented by these cores. The foraminiferal facies characteristic of cold and warm climates correlate with the alternating 

sequence of glacial-marine and warmer-water sediments indicated 

by the lithology. This correlation suggests that all the sediments in these cores are of Recent and Late Pleistocene age.

Diatomaceae.—Fifty-two species and varieties of diatoms were 

found in these cores. A large percentage of the species are neritic, 

warm-water forms that are foreign to the region today. Several
SUMMARY OF THE REPORT

alternations of warm-water and cold-water .diatom floras occur 

in most of the cores, but their position in the cores is not in 

accord with the alternations of - temperature inferred from lithology and foraminiferal facies. It is suggested that this disagreement may be due to the much longer settling time of the diatoms 

and that allowance should be made for it. The time equivalent 

of this difference of phase, as calculated from the vertical displacement necessary for the best approximation to agreement 

between the foraminiferal and lithologic data on the one hand 

and the diatom data on the other is of the order of 23, 000 years. 

This figure appears absurdly high and a figure of several hundred 

years, based on extrapolation of experimentally timed settling 

in a relatively small vessel, is considered more reasonable. The 

action of cold and warm currents, some surficial and some deep 

seated, is suggested as the possible cause of the apparently erratic 

distribution of'the diatoms. The possibility that the phase difference of 23,000 years mentioned above is related to shifts of 

ocean currents caused by advances and recessions of drift ice is 

offered as a speculation. Of 52 species and varieties illustrated, 

2 species and 1 variety are described as new.

Ostracoda.—In preparing a series of samples from the cores for 

the study of the Foraminifera about 175 specimens of Ostracoda 

were found. These belong to 13 genera and 27 species, all living 

forms, though 12 of the species are known also as fossils. Most 

of the ostracodes were found in three cores that were taken in 

the shallowest water (1,280 to 3,230 meters). One of these cores 

(No. 8) was from the top of the mid-Atlantic ridge and the other 

two (Nos. 12 and 13) were from the continental slope southwest 

of Ireland. In the cores from deeper water (3,250 to 4,820 

meters) ostracodes were scattered very sparsely. Like most 

marine ostracodes, all the species found in the cores are bottom 

dwellers. Most of the species are decidedly cold-water forms 

that are found in tropical waters only at great depth, where the 

temperature is near freezing. > Northern forms predominate; only 

2 of the species have not previously been known from northern 

waters, and 10 species are definitely Arctic forms. A few species 

that have a wider temperature range live not only in cold waters 

but also in the deep warm water of the Mediterranean.

The predominance of distinctly cold-water ostracodes and the 

prevalence of Arctic forms suggest that the temperature of the 

water in this part of the North Atlantic was formerly somewhat 

lower. But, as might be expected from the fact that all the 

species in these cores are bottom dwellers, their distribution in 

the cores shows no evident relationship to the cold and warm 

zones indicated by the composition and texture of the sediments 

and by the pelagic Foraminifera.

Mollusca.—The mollusks recovered from these cores can be 

divided into two groups, the pteropods and the other gastropods 

and pelecypods. The pteropods are by far the more numerous. 

All the specimens of the pelecypods and gastropods, other than 

pteropods, are representatives of deep-water species that are now 

living in the same boreal or cold-temperate waters. Also, the 

fragments that could not be identified specifically belong to forms 

that have congeners now living in these waters. The fauna of 

these cores, even that taken from the lower parts of the cores, 

shows no appreciable difference from that now living in the same 

localities. Among these mollusks no evidence of shallower or 

considerably deeper water is demonstrable. Molluscan remains, 

other than those of pteropods, are too scarce to attempt to 

differentiate cold- and warm-water facies, as was done with the 

foraminiferal faunas.

The Pteropoda, which are far more abundant in the cores than 

the other mollusks, belong to two genera and three species. One 

of the species is new. The geographic distribution of the pteropods is limited more by the temperature of the surface water 

than by any other factor. Nevertheless, as one species is cosmopolitan, one boreal, and one a new species thought to be the

northern analogue of a more southern species and as all three 

species occur together, they have no significance for differentiating cold- and warm-water facies. These organisms are pelagic 

and their shells have a rather wide distribution, but, as they are 

found on the sea floor at depths ranging from 247 to 3,750 meters, 

they are of little aid as indicators of depth of the ocean at the 

time these deposits were laid down.

Echinodermata.—The remains of 9 species of Echinodennata 

were found in the cores. These include 1 ophiuroid, 7 echinoids, 

and 1 crinoid. No remains of asteroids were found. All the 

echinoderms found belong to species now living in that part, or 

adjacent parts, of the North Atlantic. Echinoderm remains are 

rather uniformly distributed among the cores, but they are most 

numerous in core 8, which was taken in 1,280 meters of water 

on the crest of the mid-Atlantic ridge. By far the commonest 

species is Pourtalesia miranda, remains of which were found in 

nearly two-thirds of the 82 echinoderm-bearing samples and in 

all the cores except 8 and 11.

Because the association of species in the cores is closely 

similar to the association of living species in that part of the 

North Atlantic and because the association of species within each 

core is independent of the distance below the top of the core it 

appears that neither the distribution nor the composition of the 

echinoderm fauna has changed significantly during the interval 

represented by these cores. No evident relationship was found 

between the distribution of the various species of echinoderms 

and the cold- and warm-water facies of the sediments indicated 

by both the Foraminifera and the lithology.

Miscellaneous fossils and significance of faunal distribution.— 

The principal fossil groups represented in the cores, listed in 

order of abundance, are foraminifers, diatoms, echinoids, siliceous 

sponges, radiolarians, ophiuroids (spines and plates) ostracodes, 

and pteropods. Remains of barnacles, brachiopods, pelecypods, 

holothuroids, bryozoans, gastropods, and teleost fishes (otoliths) 

were also found, but all these are rare. The foraminifers, diatoms, ostracodes, echinoderms, pelecypods, and gastropods were 

studied separately by specialists. The other groups are briefly 

noted and illustrated for the sake of the record. The most 

varied and prolific faunas were found in the three cores that 

were taken from the shallowest water and the least varied and 

least prolific were found in those from the deepest water. The 

bottom-living faunas throughout each core have a broadly similar bathymetric facies, and the bathymetric facies of each core 

appears to correspond to that of the fauna now inhabiting that 

locality. Faunas having the characteristics of very shallowwater marine faunas are either absent or, if present, are so rare 

and etratically distributed that they appea'r to be foreign in 

origin rather than indigenous. Ostracodes and pteropods are 

locally abundant in the cores from the shallower water, but are 

absent or rare at all horizons in those from the deeper water. 

The distribution and bathymetric facies of the faunas weigh 

heavily against the hypothesis of extreme changes in ocean 

level during the later part of the Pleistocene.

Organic matter content.—The content of organic matter, as 

determined from 123 samples, ranges from 0.1 to 1.0 percent of 

the total weight of the sediments, and the average is about 0.5 

percent. As in near-shore sediments, it is influenced by the 

configuration of the sea bottom. It is small on ridges and large 

in the deeps. It is particularly large in the sediments at thfe 

base of the east' slopes of ridges, owing in part probably, to 

material washed from the vicinity of the ridges by eastwardsweeping ocean currents. The organic matter content of the 

upper layers of the sediments in the abyssal deeps is greater 

for a few hundred miles east of the mid-Atlantic ridge than it 

is for a similar distance west of the ridge. The organic content 

does not vary consistently with depth except in core three, 

taken at the foot of the continental slope east of the Grand

411574—42
SUMMARY OF THE REPORT

Banks, where it seems to decrease about 25 percent in the first 

1.5 meters. The organic matter content of the sediments tends 

to be greater in the warm zones, than in the cold zones, and in 

general it is slightly greater in sediments which, according to 

Cushman's determination of the Foraminifera, were probably 

deposited in areas in which the surface water was relatively 

warm. The organic content is rather closely related to the 

texture, and increases with increasing fineness of the sediments. 

The rate of deposition of organic matter is greater east of the 

mid-Atlantic ridge than west of it, presumably owing in part 

to a greater supply of plankton and in part to a slower rate of 

decomposition of the organic matter after it is laid down in the 

sediments. The slower rate of decomposition within the sediments is inferred from the greater state of reduction of the 

sediments, which is indicated by the nitrogen-reduction ratio. 

The nitrogen-reduction ratio suggests a slight increase in state 

of reduction with increasing depth of burial in the upper part 

of the deposits, but indicates no significant change in the lower 

part. The percentage of organic content tends to increase as 

the percentage of Foraminifera in the sediments decreases, but 

it shows no relationship*to the calcium-carbonate content.

Selenium content and chemical analyses.—As a part of a comprehensive investigation of the distribution of selenium in marine

sediments and soils derived from them complete fusion analyses 

were made of 20 samples from the suite of 11 cores. These 

samples were taken from the tops of the cores and at intervals of 

approximately 1 and 2 meters below the top. In addition, 1 

core taken on the continental shelf off Ocean City, Md., and 3 

cores from the Bartlett Deep were sampled and analyzed, making 

a total of 31 analyses. The results of the analyses include all 

the normal analytical data obtained in a so-called complete soil 

analysis by the fusion method, and, in addition, determinations 

of organic matter, nitrogen, chlorine (in all but 12 analyses), 

hygroscopic water, and selenium. All the samples were analyzed 

with the entrained sea salts. The core from the continental 

shelf off Ocean City contained the most selenium—at the top 

0.6 part per million, at 1 meter 1.0, and at 2 meters 2.0 parts per 

million. The samples from the North Atlantic cores showed a 

selenium content ranging from 0.06 to 0.8 part pe*r million. Of 

the samples from the Bartlett Deep one contained 0.2 part per 

million of selenium, but all the others contained less than 0.08 

part per million. No evidence was found of a relation between 

the selenium content and volcanic activity.

The silica-sesquioxide and silica-alumina ratios are tabulated 

and their significance as means of comparing the analyses is 

discussed.
FOREWORD

By C. S. PIQGOT l

During the last cruise (1927-29) of the nonmagnetic 

ship Carnegie of the Department of Terrestrial Magnetism of the Carnegie Institution of Washington a 

number of samples of the deep ocean bottom were 

obtained by means of the telegraph snapper. The 

Geophysical Laboratory determined the radium content 

of these samples and found that they contained a concentration of radium 2 as astonishingly high as that 

reported by Joly 3 and Pettersson 4 from similar samples 

taken by the Challenger and Princess Alice II. This 

high radium concentration in the surface layer of the 

ocean bottom, which constitutes 72 percent of the surface of the globe, raises questions of great significance 

to both oceanography and geophysics. An obvious 

"question is whether radium in so high a concentration is 

present down through all deep-sea sediments or only 

at the surface. 5 If the first hypothesis is correct it 

indicates the presence of uranium throughout the sediments, whereas the second indicates the existence of 

radium itself, presumably separated out from the sea 

water. The study of this question requires samples of a 

type analogous to the cores so extensively used in subsurface exploration on land. Inquiries among oceanographic organizations established the fact that although 

some cores a meter or more in length had been obtained 

from relatively shallow water, many of them were much 

distorted by the time they reached the laboratory, and 

none as long as 1 meter had been obtained from a depth 

of 4,000 meters or more.6 Those engaged in such research 

emphasized the need of apparatus capable of obtaining 

undistorted cores from great depths. In 1933 the 

Council of the Geological Society of America approved a 

grant for the development of such apparatus.7 Fortunately, cooperation was obtained from several special

i Geophysical Laboratory, Carnegie Institution of Washington.

1 Piggot, O. S., Radium content of ocean-bottom sediments: Am. Jour. Sci., 5th 

ser., vol. 25, pp. 229-238,1933.

3 Joly, J., On the radium content of deep-sea sediments: Philos. Mag., vol. 16, pp. 

190-197,1908.

• Pettersson, Hans, Teneur en radium <Jes depots de mer profonde: Resultats de 

Oampagnes Scientiflques par Albert I« Prince Souverain de Monaco, vol. 81,1930.

• Piggot, C. S., op. cit., p. 233.

• Since these inquiries were made D. Wolansky has published her review in the 

Geologische Rundschau (Band 24, Heft 6, p. 399,1933), in which she refers to the work 

of A. D. Archanguelsky in the Black Sea (Soc. Naturalistes Moscow Bull., new ser., 

Tol. 35, pp. 264-281,1927). Wolansky mentions cores 3 to 4 meters long from depths 

of 2,237 meters. See also Wiss. Ergeb. Deutschen Atlantischen Exped. Meteor, 

1925-27, Band 3, Teil 2, Lief. 1, pp. 4-28,1935.

7 Piggot, C. S., Apparatus to secure core samples from the ocean bottom: OeoL 

800. America Bull., vol. 47, pp. 675-684,1936.

agencies, particularly the Burnside Laboratory of the 

E. I. du Pont de Nemours, whose ballistics expert, Dr. 

B. H. Mackey, offered fundamental suggestions and 

made many essential calculations .and tests; also the 

United States Bureau of Lighthouses, from whose lightship tender, the S. S. Orchid, many experimental soundings were made. Several forms of the apparatus were 

developed and tested, and in August 1936 14 satisfactory 

cores were obtained from the canyons in the continental 

shelf off New Jersey, Delaware, and Maryland, and 

another from the ocean floor below 2,500 meters of 

water.8 This first deep-sea test was made possible by 

the cooperation of the Woods Hole Oceanographic 

Institution and was carried out in connection with an 

investigation of the submarine canyons by H. C. Stetson 

of that institution. This test demonstrated the feasibility of the apparatus as built but suggested some 

minor changes in design. These were incorporated hi 

another apparatus, which was put aboard the* cable ship 

Lord Kelvin at Halifax, Nova Scotia. Through the 

courtesy of Mr. Newman Carlton, Chairman of the 

Board of Directors of the Western Union Telegraph Co., 

the Carnegie Institution of Washington was invited to 

have a member of its staff accompany the Lord Kelvin 

while that ship was engaged in making repairs to the 

North Atlantic cables, in order to test the apparatus in 

deep water. This offer was gladly accepted, and in 

May and June of 1936 I was on board the Lord Kelvin 

with the apparatus.

Because of the personal interest and cooperation of 

the commanding officer, Lt. Com dr. Bredin Delap, 

Royal Navy, retired, the undertaking was more successful than had been anticipated, and a suite of 11 

excellent cores was obtained, extending from the Grand 

Banks of Newfoundland to the continental shelf southwest of Ireland.

All but two of these cores (Nos. 8 and 11) are more 

than 2.43 meters (8 feet) long, and all contain ample 

material for study. Of the two short cores, No. 8 was 

taken from the top of the Faraday Hills, as that part 

of the mid-Atlantic ridge is known, where the material 

is closely packed and more sandy and consequently 

more resistant; No. 11 came from a locality where the

' Cushman, T. A., Eenbest, L. O., and Lohman, K. E., Notes on a core sample from 

the Atlantic Ocean bottom southeast of New York City: Geol. Soc. America Bull, 

vol. 48* pp. 1297-1306,1937.

XI
XII FOREWORD

apparatus apparently landed on volcanic rock that may 

be part of a submarine lava flow. Soundings at the 

localities where the cores were taken show depths ranging from 1,280 meters at the top of the Faraday Hills to 

4,820 meters in the deep water between the mid-Atlantic 

ridge and the continental shelf.

The thorough test made possible by the interested 

cooperation of everyone on board the Lord Kelvin fully 

demonstrated the capacity of the apparatus and produced material from strata of oceanic sediments deeper 

than have ever before been available.

In order that this pioneer material might be" examined to the best advantage and an adequate estimate 

made of the potentialities of cores of this type, a group of 

investigators representing various fields of science was 

invited to examine them. Efforts have been made to 

arrange the sequence of these investigations in such a 

way that the maximum information may be obtained 

with the minimum destruction of the samples.

The cores are now at the Geophysical Laboratory of 

the Carnegie Institution of Washington, where they and 

others that may be obtained by this laboratory will be 

held available'for further research.
GENERAL INTRODUCTION

By W. H. BRADLEY

SIGNIFICANCE OF THE INVESTIGATION

The long cores of deep-sea sediment considered in 

this report represent a longer span of the earth's late 

geologic history, as recorded in abyssal sediments, than 

has been heretofore accessible. In a measure, therefore, this study has been exploratory. Because of that exploratory aspect we have not only presented the observations but also have deliberately speculated upon various 

possible interpretations of the features observed in the 

cores and upon their relations, with one another. Because the cores are few in number and widely spaced, 

we offer many of the interpretations not as definite 

conclusions but rather as suggestions to be tested by 

whatever coring may be done in the future in that part 

of the North Atlantic.

From this investigation it appears that glacial marine 

deposits may prove to be sensitive indicators of the climatic changes that caused the growth and decay of 

continental ice sheets during the Pleistocene. In particular, it seems that the glacial marine record may 

throw light on the climatic fluctuations that determined substages of the Pleistocene. The marine 

record was the result of a continuously operating series 

of causes such that the deposits of each glacial substage 

were separated from one another by the deposits of the 

intervening warmer substage. The record of each 

substage has remained intact and was not obliterated 

by readvances of the ice. As the equatorward extent 

of the glacial marine deposits implies a corresponding 

expansion of continental ice sheets, the extent of the 

deposits may be used as a measure of the intensity of 

the climatic changes, and their thickness may be used 

as a rough indicator of the duration of glacial substages. 

Similarly, the thickness and poleward extent of tongues 

of nonglacial sediment—the foraminiferal marl—are 

measures of deglaciation. The areal extent of these 

tongues of sediment can be determined by additional 

cores taken at properly located stations.

When the glacial marine record is more fully known 

it should provide a basis for correlating the Pleistocene 

history of Europe and North America.

Cores taken along the meridians in series extending 

from the Arctic regions into the tropical parts of the 

Atlantic should make it possible to map the southern 

limits of pack ice in the sea during successive glacial 

maxima, at least for the later part of the Pleistocene.

As the pelagic Foraminifera in these abyssal sediments 

are reliable indicators of surface-water temperatures in 

the Recent and Pleistocene epochs, it should be possible 

to trace southward into the tropics layers or beds of 

foraminiferal ooze that are the time equivalents of 

glacial marine zones. Such layers of foraminiferal ooze 

could then be correlated with the layer of globigerina 

ooze in the tropics that Schott 9 identified as a relatively cold-water deposit that probably represents the 

last glacial epoch of the Pleistocene.

The study of climatology as well as geology may be 

advanced by the information to be derived from long 

sea-bottom cores. Significant evidence bearing on postglacial climatic changes may be obtained from minutely 

detailed study of the Foraminifera in cores taken in 

parts of the ocean where postglacial sedimentation has 

been comparatively rapid, as, for example, near the 

seaward edge of the blue-mud zone. On the assumption that such sediment accumulates at an essentially 

uniform rate, climatic fluctuations may be located approximately hi time within the postglacial interval and 

may be correlated from place to place along the ocean 

margins from the Arctic to temperate or even tropical 

latitudes and perhaps also from continent to continent.

Archeology, also, might profit from the knowledge 

of a relatively tuned and correlated sequence of climatic changes, for such changes may we}! have made a 

significant impress on the habits and migrations of 

peoples, particularly those that dwelt in regions where 

small changes in either temperature or rainfall were 

critical. As I have pointed out in an earlier paper,10 

students of archeology and early history, particularly in 

the Mediterranean region, might profit much from 

detailed studies of long cores of the sediment in the 

deep basins of the Mediterranean. In cores from that 

sea, as elsewhere, changes in the foraminiferal faunas 

would indicate climatic changes, and the sediments 

would yield, in addition, evidence of volcanic eruptions 

and earthquakes. The time when the Sahara became 

a desert should also be recorded in the Mediterranean 

sediments by wind-blown sand, Such a change might 

conceivably be integrated with the wealth of archeo-

• Schott, W., Die Foraminiferen in dem aquatorialen TeD des Atlantischen Ozeans: 

Wiss. Ergeb. Deiitschen Atlantischen Exped. Meteor, 1925-27, Band 3, Teil 3, Lief. 1, 

pp. 120-128,1935.

»»Bradley, W. H., Mediterranean sediments and Pleistocene sea levels: Science 

new ser., vol. 88, pp. 376-379,1938.

xm

411574—42———3
XIV GENERAL INTRODUCTION

logical records of the region, and the later volcanic 

eruptions and earthquakes might be correlated with 

early history.

Some of the problems sketched so briefly here are 

touched upon in the several chapters of this report, 

but most of them must be left for future investigators. 

Nevertheless, methods by which such problems may 

be attacked are described and discussed at considerable 

length, particularly in the chapters on "Lithology and 

geologic interpretations" and "Foraminifera."

LOCATION OF THE CORE STATIONS

The cores were taken along a slightly irregular line 

between the easternmost part of the Newfoundland 

Banks and the banks off the southwest coast of Ireland, 

as shown in plate 1. Each core obtained by the Piggot 

coring device is numbered to correspond with the station 

number of the cable ship Lord Keli.in. Stations 1 and 

2 were trial stations at which preliminary tests were 

made to familiarize the crew with the apparatus, and 

no cores were preserved. The 11 cores studied are 

numbered consecutively, 3 to 13. The relation between

M. N. Bramlette, J. A. Cushman, L. G. Henbest, K. E 

Lohman, and P. D. Trask. As the biologic phase of 

the work progressed it became evident that other 

organisms than the foraminifers and diatoms should be 

studied. Accordingly Mr. Henbest invited Dr. Willis 

L. Tressler, of the University of Buffalo, to examine the 

ostracodes, Dr. Austin H. Clark of the United States 

National Msueum, to examine the echinoderms, and 

Dr. Harald A. Rehder, also of the United States 

National Museum, to examine the mollusks.

The organic matter content of the sediments was 

studied by Mr. Trask in collaboration with Messrs. 

H. Whitman Patnode, Jesse LeRoy Stimson, and John 

R. Gay, all members of the American Petroleum 

Institute.

As part of a comprehensive research project on the 

distribution of selenium in marine sediments and the 

soils derived from them Dr. H. G. Byers and Mr. Glen 

Edgington, of the Bureau of Chemistry and Soils, 

United States Department of Agriculture, made complete chemical analyses of 20 samples from these deepsea cores. These analyses, together with analyses of

w.

ST. JOHNS 

NEWFOUNDLAND 

Meters 

0

5.000

MID-ATLANTIC RIDGE 

" FARADAY HILLS" 

6 789 1213

E.

LANDS END 

ENGLAND

FIGURE 1.—Profile across the North Atlantic Ocean along the Itne of the numbered core stations shown on plate 1.

the core stations and the submarine topography is 

shown in figure 1, which is a profile along the dashed 

line in plate 1 that connects the stations and extends 

from St. Johns, Newfoundland, to Lands End, England."

TABLE 1.—Geographic location, length of the cores, and depth of 

the water from which they were taken

Core number

3......... __„„__„____„.___„„___„

4... ____________ . ____

5. ___ .—-..-—.....-..._._ ......

6__ _ . ___ .. ____ .. __ .. _____ .

7_. __________________

8.................. _ ... ___ ......

9..-. _ -.-—..„..____• ......

10— ———.. ——......._________

11.... __ . __ . _ .. . _ ...

12... ... .............. .............. .

13- ___ : .....................

Depth 

of water 

(meters)

4,700

3,955

4,820

4,125

3,250

1,280

3,745

4,190

4,820

3 9^n

1,955

Length 

of core 

(meters)

2.81

2.71

2.82

2 on

2.62

1.24

2.76

2.97

.34

2.21

Lat. N.

46°03'00"

48°38'00"

£QO/y>/0|y/

49°32'00"

AQOOf'/nnft

49°45'00"

^cOQfl'nft"

£Q°37'ftA"

49°38'00"

Long. W.

joooqmn//

ococ,f/9iy'

9Q°91 'flfV'

OQOc4/rift"

9S2°9Q'niV/

17°ftQ'An"

i9°QA'ftn"

lOOoQ'Afi"

PERSONNEL AND COMPOSITION OF THE REPORT

At the request of Dr. C. S. Piggot, of the Geophysical 

Laboratory of the Carnegie Institution of Washington, 

the following six members of the United States Geological Survey undertook a systematic study of the 11 

deep-sea cores from the North Atlantic: W. H. Bradley,

11 Data for plate 1 and figure 1 were taken from International Hydrographic Bureau, 

Carte Gentoals Bathymetrique des Oceans, 3d ed., sheets A-l and B-l, copies of 

which were furnished by the U. 8. Hydrograpnic Office.

samples from several other deep-sea cores and a discussion of the occurrence of selenium, are included in 

the chapter on "Selenium content and chemical 

analyses."

METHODS OF SAMPLING AND EXAMINATION

The Piggot coring device 12 takes the cores in brass 

sampling tubes that have an inside diameter of 4.9 cm. 

As soon as a core is taken, the tube is cut off at the 

approximate length of the core and sealed. The cores 

here discussed were opened under Dr. Piggot's direction 

at the Geophysical Laboratory of the Carnegie Institution of Washington. A longitudinal cut was made 

along one side of each brass core barrel by means of a 

milling cutter so adjusted that it did not cut quite 

through the wall of the tube. The thin strip remaining 

was then ripped out without letting brass chips get 

into the core. After allowing the mud cores to dry 

somewhat,. but not enough to shrink away from the 

tube walls, the cores and core barrels were cut hi half 

longitudinally with a metal-cutting band saw. In this 

cutting, the milled slot was held uppermost so that the 

saw cut only the lower wall of the core barrel and 

threw the cuttings downward, away from the core.

11 Figgot, G. S., Apparatus to secure core samples from the ocean bottom; Gaol. 

800. America Bull., voL 47, pp. 875-684,1936.
GENERAL INTRODUCTION

Each half core then remained undisturbed in its half 

cylinder cradle of brass core barrel. (See pi. 2.)

As several months elapsed between the tune the cores 

were opened and the time this investigation began, the 

mud had dried thoroughly when Mr. K. E. Lohman 

took a succession of overlapping photographs of each 

core, about one fifth natural size. These photographs 

were then assembled as a key chart upon which were 

marked the parts from which samples for all phases of 

the investigation were taken. The dried segments' of 

mud shifted somewhat from their original places each 

time samples were removed, though care was taken

to see that during sampling the segments kept their 

original order and orientation. By reference to this 

photographic key the findings of all the investigators 

have been correlated.

Most of the material was hard enough to be sawed 

into blocks with a hack saw, but a few of the most 

friable parts were sampled with small channel-shaped 

scoops of sheet metal after the loose material on the 

surface had been brushed away.

Samples for all phases of this investigation were 

taken from only one half of each core, the other half 

being held intact in the Geophysical Laboratory.

GEOLOGICAL SURVEY

60° (Follows p. XV) PROFESSIONAL PAPER 196 PLATE 1

Sea level to 

500 meters

500-2,000 

meters

2,000-4,000 

meters

4,000 -6,000+ 

meters

BATHYMETRIC CHART OF A PART OF THE NORTH ATLANTIC OCEAN.

The numbered circles indicate the core stations. The dashed line connecting them is the line of the profile shown in figure 1. The light dotted line along the coasts is the 200-meter depth contour. The usual limit of drift ice is shown by the heavy dotted line. The small triangles indicate the position of icebergs reported far beyond their normal range during the period January 1900 to July 1916, according to information compiled by J. T. Jenkins (A Textbook of Oceanography, fig. 14, London, Constable & Co., 1921).

GEOLOGICAL SURVEY PROFESSIONAL PAPER 196 PLATE 2

5678 9 10 12 13

LONGITUDINAL SECTIONS OF THE AIR-DRIED CORES. 

Half of the core barrel was removed from core 11, but the core itself was not cut. Photograph by Geophysical Laboratory, Carnegie Institution of Washington.

GEOLOGY AND BIOLOGY OF NORTH ATLANTIC DEEP-SEA CORES 

BETWEEN NEWFOUNDLAND AND IRELAND

PAET 9. SELENIUM CONTENT AND CHEMICAL ANALYSES

By GLEN EDGINGTON and H. G. BYEES *

INTRODUCTION

For several years the Division of Soil Chemistry and 

Physics, formerly under the Bureau of Chemistry and 

Soils but now a part of the Bureau of Plant Industry, 

has been interested in analyses of profiles of soils and 

also in the origin and distribution of selenium in surface 

formations. For both these reasons the opportunity 

to examine chemically the sea-bottom cores, which 

were made available through the kindness of Dr. C. S. 

Piggot, was extremely welcome. These offer for the 

first time submarine profile samples for examination 

and comparison with samples of soil profiles, lacustrine 

deposits, and delta deposits. Though numerous samples of deep-sea deposits from various sources have 

been available, there is a singular absence of complete 

fusion analyses. These are virtually limited to analyses 

of a composite of 51 samples of red clay and of 52 samples of terrigenous clays by G. Steiger.2 These samples 

are partly collections from the Challenger expedition 

and partly from other expeditions. There are also 

analyses by Brazier and by Hornung 3 of the acid-soluble 

and acid-insoluble portions of a considerable number 

of individual sediments; also 14 analyses by Caspari.4 

These may be combined to give the composition of the 

sediment as a whole.

Many partial analyses of samples of ocean sediments 

are available from various sources, such as those by 

Fairchild on samples from Pago Pago Harbor 5 and from 

the Gulf of Maine.6 In addition, Twenhofel 7 has 

summarized numerous analyses of surface material, 

such as glacial, lacustrine, and delta deposits.

i Glen Edgington, assistant chemist, and H. G. Byers, principal chemist, Division 

of Soil Chemistry and Physics, Bureau of Plant Industry.

»Clarke, F. W., The data of geochemistry: U. S. Geol. Survey Bull. 770, p. 518, 

1924.

* Murray, John, and Renard, A. F., Challenger Rept., Deep sea deposits, pp. 425- 

451,1891.

* Caspari, W. A., Composition and character of oceanic red clay: Eoyal Soc. Edinburgh Proc., vol. 30, pp. 183-201, 1910.

* Bramlette, M. N., Some marine bottom samples from Pago'Pago harbor, Samoa: 

Papers Dept. Marine Biol., Carnegie Inst. Washington, vol. 23, pp. 9-23, 1926.

« Wells, R. C., Analyses of rocks and minerals: U. S. Geol. Survey Bull. 878, p. 67, 

1936.

' Twenhofel, W. H., Treatise on sedimentation, 2d, ed., pp. 3-32, 247-276, Williams 

and Wilkins, 1932.

A great number of analyses of sedimentary deposits, 

which are now, or may become, parent material for 

soils, are also available.8

The analyses presented herewith include not only 

20 samples selected by Dr. C. S. Piggot from the North 

Atlantic cores but also 3 samples from a core taken off 

Ocean CiVv, Md., and 8-samples from 3 cores taken in 

the Bartlett Deep, in the Caribbean Sea. These 

additional samples offer some interesting relationships 

with those from the North Atlantic.

ANALYTICAL PROCEDURE

Our primary purpose in making these analyses was 

for comparison with soil and shale analyses. These 

comparisons will be more fully discussed elsewhere 

when more cores have been examined and especially 

when colloid data are available.

The cores from the sea bottom were prepared for 

analysis in accordance with the methods used by the 

United States Department of Agriculture in analyzing 

soils.9 More extensive descriptions of the fundamental 

methods have been given by Hillebrand and Lundell. 10

The dried salts from sea water were not removed 

from the samples before analysis. If these had been 

removed by leaching, the results would have more 

closely simulated the actual composition of the sediments. However, such leaching, especially if extended, 

may remove some material that should properly be 

regarded as a part of the sediment. The results as 

obtained are a combination of the actual insoluble 

material and the amount of sea-water salts held by the 

sediment on drying. The amount of salts held by the 

sediments varies of course with the size of the particles 

and perhaps with the composition of the material.

The chlorine determinations represent the total 

chlorine in the sample. Analyses were made on 10 

ignited saline samples to determine to what extent

« Clarke, F. W., op. cit., pp. 543-593.

• Robinson, W. O., Method and procedure of soil analysis used in the Division of 

Soil Chemistry and Physics: U. S. Dept. Agr. Circ. 139, pp. 1-20,1930.

10 Hillebrand, W.F., The analysisof silicate and carbonate rocks: U.S. Geol. Survey 

Bull. 700, pp. 1-285, 1919. Hil'ibrand, W. F., and Lundell, G. E. F., Applied inorganic analysis, with special reference to the analysis of metals, minerals, and rocks, 

pp. 645-849, New York, John Wiley and Sons, 1929.

151
152 GEOLOGY AND BIOLOGY OP NORTH ATLANTIC DEEP-SEA COKES

the chlorine was lost by ignition. The results are 

given hi table 34.

TABLE 34.—Chlorine content of dry sample and chlorine lost by 

ignition

Sample number

B22595___. 

B22596 __ 

C3938_____

C3939 

C3940 

C3941____.

C3942._...

C3943__._.

C3944_____

C3945____-

Cblorine 

in oven-dry 

sample 

(percent)

1.55 

1.84 

1.03

1.03 

1.06 

1. 26

1. 26

1.42

1.22

1. 11

Chlorine 

in ignited 

sample 

(percent)

0. 11 

.26 

. 11

.09 

.23 

.25

. 11

.23

. 10

.24

It is evident that not all the chlorine was volatilized 

by heating to a constant weight at about 900° C. In 

determmuig the loss on ignition, some of the samples

came to a constant weight by heating for 1 hour, whereas 

others required as much as 3 hours. Unfortunately, 

chlorine determinations were not made on all the samples analyzed.

The percentage of constituents is reported on the 

oven-dry basis. The inorganic constituents plus the 

ignition loss should equal very nearly 100 percent. The 

ignition loss includes constituents otherwise reported, 

such as nitrogen, carbon dioxide, organic matter, 

chlorine, and combined water.

ANALYTICAL RESULTS

All the analytical data obtained on the 31 samples 

examined are assembled in table 35. They include, in 

addition to the normal analytical data obtained hi a 

so-called complete soil analysis by the fusion method, 

organic matter, nitrogen, chlorine, hygroscopic water, 

and selenium. No attempt has been made to determine the quantities of minor elements probably present 

in the material.
TABLE 35.—Chemical analyses of samples from sea-bottom cores 1

[Composition expressed in percent, except for selenium, which is expressed in parts per million] 

Ocean floor off Ocean City. Md.

Field 

number

1... ........

2...........

3—...—— .

Laboratory 

number

B20610.....

B20611.-...

B20612.— .

Distance

below top 

of core 

(centimeters)

100

200

SiOa

61.12

58.45

57.51

TiOj

0.61

.65

.70

A13 0,

9.62

10.26

9.72

FeaOs

3.22

3.74

3.74

MnO

0.05

.06

.06

CaO

7.29

7.46

8.53

MgO

1.63

1.88

1.86

KjO

1.88

2.07

1.96

Na2O

2.34

2.29

9 17

P3 05

0.13

.16

.18

SO3

1.00

1.52

Ignition 

loss

10.86

11.57

11.88

Total

99.75

100. 11

100. 06

Nitrogen

Carbon 

dioxide

5.50

5.60

6 47

Ocean floor of North Atlantic between Newfoundland and Ireland

3-A7>—— ._

3-A8.— ...

3-A9.......

4-A20-.— .

5-A19.......

5-A11......

5-A12.. — .

6-A18- ——

7-A17.. — .

7-AlO.-— .

8-A16-— . .

9-A15. _ ..

9-A13- ——

10-A4_—— _

10-A5- ——

10-A6......

12-A14.....

13-A1-— ..

13-A2.... ._

13-A3-.——

B20639.....

B20640.....

B20641.....

B22598-...

B22597.....

B 22589.....

B22590.....

B22596— ..

B22595-....

B22588.....

B22594— _.

B22593— ._

B22591-....

B20636-...

B20637-—.

B20638....

B22592.....

B20633-....

B20634. _

B20835-. .

100

200

Top

Top

110

155

135

100

200

Top

100

200

• 32. 40

32.72

36.62

32.65

46.01

45.99

1Q 44

18.05

36.04

38.94

15.34

34.28

42.29

42.55

53.83

17.98

38.18

35.47

42.87

0.50

.48

.57

K4

.46

.57

.43

V)

.26

.46

.56

.20

.52

.55

QO

'.27

.45

.35

.44

8.30

7.90

9.42

8.57'

7.53

9.73

5.71

3.97

7.67

6.04

3.65

8.05

13.08

8.54

13.28

5.24

7.23

6.58

6.46

3.61

3.58

4.17

q no

3 9fi

2

07

1.72

3

00

2.68

2.05

4.04

8.72

3.38

5.89

2.02

2.88

2.44

2.86

0.13

.12

.15

.14

.12

.09

.09

1 ^

.10

.10

.07

.28

.09

.16

.11

.10

.08

.10

.05

.04

23.89

24.11

20.51

25.04

28.04

14.96

1 K KQ

QK fi9

39.13

94 41

25.92

38.96

22.96

9.42

18.32

7.30

37.42

24.50

27.14

22.72

2.82

2.81

3.34

9 74

2.28

3 79

1.74

1.30

9 fi£

1.63

1.26

2.38

4.00

3.30

2.92

1.29

1.76

1.49

1.39

1.51

1.48

1.64

I

RA

1 ^7

2 19

1 Q.4.

01

.66

1.42

.98

.63

1.58

1.86

1.81

2.68

.98

1.38

1.20

1.21

3.20

2.99

3.00

2 fi7

2 fi7

f) AK

2.18

2.06

1.71

1.85

1.36

2.39

2.85

4.67

2.28

2.82

1.24

1.52

1.57

1.44

0.07

.11

.12

.15

no

13

.12

.06

.05

.05

.15

.11

.19

.13

.12

.13

.12

.12

.09

0.43

.51

.42

01

OQ

.16

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100.06

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Floor of Caribbean Sea at Bartlett Deep

135-A1.....

135-A2.... .

136-Al. — _

136-A2. — _

136-A3.— .

137-A1..—

137-A2.....

137-A3.....

C3938— ...

C3939— ...

C3940......

C3941......

C3942... ...

C3943- _ .

C3944____._

C3945— ...

6-10

100

100

190

100

190

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21.92

20.72

25.89

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6.86

9.38

8.70

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4.05

3.91

4.95

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16.78

37.09

29.20

30.94

32.29

27.70

29.57

3.21

3.48

1.60

2.00

2.11

2.17

2.50

2.64

1.10

1.24

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.86

.71

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2.30

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1.48

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1.72

1.93

1.69

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100. 69

99.75

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99.75

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100. 57

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15.28

11.43

28.02

21.71

23.34

23.85

20.10

21.64

1 The geographic location of each of the cores is listed below: 

OCEAN CITY, MD. NORTH ATLANTIC BETWEEN NEWFOUNDLAND AND IRELAND

1-3.............._...... 37°26'N., 74°28'W. 3-A7 to 3-A9--.......... 46°03' N., 43°23' W.

4-A20—.................. 48°29' N., 35°54'30" W.

5-A19, 5-A11, 6-A12...—— 48°38' N., 36°01' W.

6-A18————— —— ———— 49°03'30" N., 32°44'30" W.

7-A17, 7-AlO....—.—.... 49°32' N., 29°21' W.

8-A16.—————..... 49°36' N., 28°54' W.

9-A15, 9-A13..._...... 49°40' N., 28°29' W.

10-A4 to 10-A6————- 49°45' N., 23°30'30" W.

12-A14................... 49°37'N., 13°34'W.

13-A1 to 13-A3— ——.... 49°38' N., 13°28' W.

135-A1, 135-A

136-A1 to 136

137-A1 to 137

* The numbers in this column to the left of the letter A are the numbers used in the preceding chapters of this report to designate the cores taken between Newfoundland and Irela

INDEX

Page

Acknowledgments for aid_._____._____.___.__._... xi,xiv 

Age of sediments..--._____________..___._....._____ vm 

Analyses, chemical._._.___._____________________ x, 151-155 

mechanical._________________________________ vm 

Archeology, significance of core study for___ _________ _____ xm-xrv 

Ash, volcanic, composition and distribution.._________________ Yh

Barium, in sediments____.-...-.-..-...____......_..._......_. vm

Bartlett Deep, sediments from, analyses of_•__ __________... 153

sediments from, selenium in.........__________....__..... 155

silica-alumina and silica-sesquioxide ratios of._____________ 155

Basaltic glass, occurrence and character of....________________ vm

Bering Sea, sediments from, selenium in._____.__..._.._____ 155

Boron, in sediments...._____-....__.____...._______ vm

Bottom currents, evidence of..._________________________ vn 

Bradley, W. H., introduction by..______.__....__.______ xm-xv

Carbonate, in sediments....______________.__________ vm, 154

Caribbean Sea, sediments from, analyses of..._._..._._.......___ 153

sediments from, silica-alumina and silica-sesquioxide ratios of. ___ _.. 155 

Carnegie Institution of Washington, work on deep-sea cores by____.. vn, xi, xrv 

Chlorine, determination of_ ___ ___.___.________ _____ 151-152 

Clay, silica-alumina and silica-sesquioxide ratios of__.__..__..__ 155 

Climate, relation of sediments to._..____..___.___... vn, vm, x, xm 

Core samples, methods used in obtaining ___________________ xrv-xv 

preparation of.-----.-.._._--------_.........._..._______ 151

source of_______________________.____________ 151 

Core stations, location of.__.__..___._____..._______ xiv

Correlation of zones represented in the cores.. _______._________ vu 

Crinoids, in sediments..._______..._________...____.. rx 

Currents, bottom, evidence of.._________________________ vn

Diatomaceae...—__—____...___________-.---..___ vm-ix

Diatoms, distribution of, in sediments...-.________________. vn-rx

Echinodermata._________________________________ ix

Echinoids, association of.__________________________ ix

Elphidiella.-——.—————_-...-—..—...................... vm

Elphidium...___________________________________ vm

Farraday Hills, features of.__,______________ __________ xiv 

Faunas, distribution of..________...._..__.....__........ rx

Fecal pellets, evidence of, in sediments... — __________________ vm 

Foraminifera, age and correlation of. _ -...__..--•----.________ vm

distribution and environmental significance of..___________ vn-vm 

Foraminiferal marl, meaning of term_____________________ vn-vm 

Fossils, miscellaneous, distribution of._________________ rx;

Gastropods, environment of__ _____________.___________ rx

Glacial marine deposits, age of—________..______________ vn

features of ________. _________________________ vn

Glass shards, occurrence and character of...——___....__..._____ vm

Globigerina ooze, meaning of term......_-_..—__......—..__..... vn-vm

Grain size of sediments....__________—_____.________ vm

o

Page 

Introduction to complete report..._____—————-—————————— xm-xv

Lithologic zones in cores, correlation of._.-.._——————————————— vn 

Lithology and geologic interpretations.___—_..——.————————— vn-vm 

Location of region studied_——....——————————————————— vn,xr,xiv

Mediterranean Sea, sediments in, significance of.— ———_.—————— xm-xrv 

Marl, foraminiferal, meaning of term____-...--. —.. ——— —— — —— vn-vm 

miranda, Pourtalesia._.__.....—————————————.. ———— ———— ix

Mississippi Delta, silt from, silica-alumina and silica-sesquioxide ratios of. —— 155 

Mollusca__________——_..————————————————————— ix 

Mud-feeding organisms, role of...__———... — —— ——— —. — —...- vn

Ocean City, Md., sediments near, analyses of__—__... ——— — ———.. 153

sediments near, selenium in_______..—————.—————————— 155

silica-alumina and silica-sesquioxide ratios of.——— —— ——— ——— 154

Ophiuroids, association of. ————... ——— ———— —— —————————— rx

Organic content of sedim'ents. —————.——————————————————— rx-x

Ostracoda____________.__~~——————————————————— ix

Outline of complete report—_...__--..-.-. — — - ——— ------ — —.—— v

Palagonite, character and occurrence of.-..—— ———————— ——————— vra 

Pelecypods, environment of....—.._ — —— -..- ———— — — —————— ix

Piggot, C. S., coring device designed by... ————.—————————— vn, xiv-xv 

foreword by...-__ ———-—--- — —————————— —— ———— xi-xn

Plankton, relation of, to organic content..-.-.-———————————————— x 

Porosity of the sediments__.---.__.-———————————————————— vm 

Pourtalesia miranda____—-.....--. —... — ——— —— — — — ——— ix

Pteropod shells, distribution of.—___————.—————————————— vm,ix

Radium, concentration of, on ocean bottom..— ————. ———— —————— xi 

Eare elements, spectroscopic tests for...———————————————————— vra 

Region sampled, extent of.————-..——————————— — ——— — — — vn, xi

Sampling and examination of cores, method of.— — ———————— — — xiv-xv

Sediments, age and correlation of __———.—————————————————— vm

grain size of._—————————————————————————————— vra

organic content of._————..——————————————————————— ix-x

selenium in_———————————————————————————————— 155

silica-alumina and silica-sesquioxide ratios of._..--__——————— 154-155

source of—-___——— — ———————— ——————————————— — 154

Selenium content of sediments_ _ ____———— ———— -————————— x, 155

Silica-alumina and silica-sesquioxide ratios of sediments.————————— 154-155

Silt, silica-alumina and silica-sesquioxide ratios of.——————————————— 155

Spectroscopic tests of sediments—_..————————————————————— vra

Summary of complete report_ ______————————————————— vra-x

Temperature, relation of type of sediment to.—.———— ——— —— — — vn,vm, x 

Texture of sediments, relation of, to organic content——————————————— x

Uranium, in ocean sediments.——....————————————————————— xi

Volcanic ash, composition and distribution of....__..—..-. ——— —— —— vn 

Volcanic glass, occurrence and character of..-.-...————.————————— — vm

Zones represented in the cores, correlation of...———————————————— vn

XVII

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