9. SITE 218
The Shipboard Scientific Party1

ABSTRACT

Situated in the central Bengal Fan in 3749 meters of water,
Site 218 was drilled to 773 meters in a turbidite sedimentary
sequence. The stratigraphic column, which was only partly
penetrated, comprises several sedimentary units which include
silts, sandy silts, and clayey silts, interbedded with nannofossil
ooze layers. These range in age from Quaternary down to middle
Miocene at the bottom of the hole. On the basis of dominantgrain sizes of the terrigenous sediments and the distribution of
pelagic material, four distinct "pulses" of turbidity current
activity resulting in coarse sediments are tentatively recognized.
One of these occurs in the middle Miocene, two in the upper
Miocene-lower Pliocene, and one in the Pleistocene. The youngest"pulse" is overlain by several meters of pelagic ooze, suggesting
postglacial cessation of turbidity current activity in the area ofthe site.
SITE DATA
Date Occupied: 1 Mar 72 (1030)
Date Departed: 4 Mar 72 (1030)
Time on Site: 72 hours
Position:lat 08°00.42'N
long86°16.97'E
Water Depth (to rig floor);
3737 meters (Echo sounding)3759 meters (Drill pipe)
Penetration: 773 meters
Number of Holes: 1
Number of Cores: 27
Total Length of Cored Section: 251 meters
Total Core Recovered: 59.4 meters
Acoustic Basement:
Depth: ? meters
Nature: UnknownAge of Oldest Sediment: Middle Miocene
Basement: Not reached1
C. C. von der Borch, Flinders University, Bedford Park, South
Australia; J. G. Sclater, Scripps Institution of Oceanography, La
Jolla, California; S. Gartner, Jr., Rosenstiel School of Marine andAtmospheric Science, University of Miami, Coral Gables, Florida;
R.Hekinian, Centre Oceanologique de Bretagne, Brest, France; D. A.
Johnson, Woods Hole Oceanographic Institution, Woods Hole,
Massachusetts; B. McGowran, University of Adelaide, Adelaide,
South Australia; A. C. Pimm, Scripps Institution of Oceanography;
La Jolla, California; R. W. Thompson, Humboldt State College,
Arcata, California; J. J. Veevers, Macquarie University, North Ryde,
N.S.W., Australia; Lee S. Waterman, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts.

BACKGROUND AND OBJECTIVESThis site was chosen on the basis of Curray and Moore's(1971) identification of two prominent unconformities
between the sediment units of the Bengal Fan, which werecalled W, Y, and 0 , in order of increasing age. These
unconformities were interpreted in the authors' working
hypothesis as being associated with the last two epochs ofmajor Himalayan orogeny in the Plio-Pleistocene andMiddle Miocene. Correlation of unconformities led theauthors to believe that the Y section was uplifted andoutcropped both on the northern end of the Ninetyeast
Ridge and on a small knoll just south of Site 218. The
continuous chalk section at Site 217 is clearly not a Bengal
Fan turbidite, and the similarity between it and theacoustic records from the knoll suggested that the sediments from the knoll could also have been a continuous
calcareous pelagic sequence. This possibility could be tested
by following the original proposal to sample the upper W
section through the upper unconformity and drill as deeply
as possible.
The depth of the sediment was estimated at 3.5 to 4.0
kms from seismic refraction profiles. This and a basement
age of 80 m.y. give an estimate of 50 m/m.y. for a uniform
sedimentation rate. A realistic estimate of the maximum
possible depth of drilling was 1000 m. It was hoped that wewould be able to sample part or all of the products of the
Neogene denudation of the Himalayas.

OPERATIONS
Site 218 was drilled in a turbidite sequence on the
Bengal Fan, in a water depth of 3759 meters (drill pipe to
rig floor). The site was occupied on 1 Mar 1972 at 1030
hours.
325

SITE 218

A Smith, 4-cone chizzel-tooth bit was used, and threecores were taken continuously at the top in mediumgrained silty sands. From a sediment depth of 23 meters,
one core was taken for every 28.5 meters of drilling down
to 450 meters. Continuous coring was carried out between
450 meters and 507 meters, after which spot coring every
28.5 meters was again employed to the bottom of the holeat 773 meters.
No serious drilling difficulties were encountered, despite
the fact that the hole was drilled through a major turbidite
sequence. The clay and silt content of the sands and theclayey and pelagic ooze and chalk interbeds apparently
supported the hole.
Drilling was terminated at a sediment depth of 773
meters within the turbidite sequence due to shortage oftime. A total of 251 meters of sediment was cored, with arecovery of 59.4 meters, representing 24% recovery (Table
1)
LITHOLOGIC SUMMARY

The stratigraphic section penetrated at Site 218 consists
principally of a turbidite sequence of interbedded andinterlaminated sandy silt, clean silt, and clayey silt ranging
in age from Quaternary to middle Miocene (Figure 2).
Relatively minor amounts of silty sand and silty clay were
found. Near the surface and at several depth intervals,
pelagic nannofossil ooze occurs interbedded with theturbidites.
Because of the discontinuity of coring, poor recovery,
and general similarity of the sediments throughout much of
the hole, no well-defined lithologic units are distinguishable. A textural zonation of possible significance isapparent in the section, however, when various sedimenttypes are grouped as follows and their distribution plotted
as a function of depth: (1) Silty sand, sandy silt, and cleansilt; (2) Silty clay and clayey silt; and (3) Pelagic sediment,
principally clay-rich nannofossil ooze. The percentage,
based on thickness, of each of these groups in each core wasdetermined in very rudimentary fashion and plotted at
depths corresponding to the midpoints of appropriate cores(Figure 2). The textural plot indicates that the section isdivided into several zones of relatively coarse terrigenous
sediments (identified as "pulses") which are separated byzones of finer terrigenous sediments interbedded withpelagic oozes. General lithologic units based primarily on
this zonation are outlined and discussed below. Interpretation of the zones is discussed in the Summary andConclusions.
Unit 1 (Cores 1,2)This unit consists principally of olive gray to darkgreenish gray, silt-clay-rich nannofossil ooze. Nannofossils
constitute from 40% to 70% of the sediment, while
terrigenous silt and clay typically average 10% to 20%.
Other common constituents include foraminifera, Radiolaria, and diatoms. Interbeds of olive gray nannofossilbearing clayey silt up to 1 meter thick occur in the section.
Unit 2 (Cores 2-4)
Olive gray nannofossil-bearing clayey silt with gradedinterbeds of silty sand and sandy silt characterize the upper

326

Unit

Depth
Below Sea
Floor
(m)

1

0-9

2

9-70

3

70-2254

225-3505

350-4706

470-6007

600-650(?)

8

650-773

Lithology

Age

Cores

Clay silt-rich nanno ooze
with interbeds of silty
clay
Silt with interbeds ofsand, sandy silt, andclayey silt
Nanno-rich clayey silt
and silty clay with interbeds of nanno ooze
Silt with interbeds ofsilty sand and clayey
silt
Clayey silt and silty
clay with occasional
interbeds of nanno ooze
and sandy silt
Interlaminated cleansilt, clayey silt, andsandy silt with occasional
interbeds of mottled
nanno ooze
Interlaminated clayey
silt, silty clay, andsandy silt with interbeds
of nanno ooze
Interlaminated cleansilt, sandy silt, andclayey silt

Quaternary

1,2

Quaternary

2,4Quaternary- 5-9
Pliocene
Plioceneupper
MioceneUpper
Miocene

9-12

Upper
Miocene

17-22

Upper
Miocene23,24

MiddleMiocene

24-27

13-16

parts of Unit 2. Lower in the unit (Cores 3 and 4), clean,dark gray silt with sandy silt laminations predominates.
Occasional mottles (clasts?) of clay-rich nannofossil ooze
occur in one 70-cm silt bed. The principal mineral
constituents of the silts and sandy silts include feldspar andquartz (5O%-75%), undifferentiated clay (10%-25%), mica
(5%-15%), calcite (l%-3%), and heavy minerals (l%-5%).
Particularly common among the heavy minerals are hornblende, epidote, opaques, garnet, pyroxene, and tourmaline(see Chapter 38). The prevalent sand size is either very fineor fine, but ranges up to medium.

Units 3, 5, 7 (Cores 5-9, 13-16, 23, 24)These are relatively fine-grained units (see Figure 1) inwhich the predominant lithologies are olive gray to darkgray clayey silt and gray silty clay. Both lithologies, whichmost commonly occur in beds the order of 30 to 70 cm
thick, contain thin (generally <IO cm) graded beds ofsandy silt and clean silt. Occasional interbeds of greenish
gray to yellow green clay bearing nannofossil ooze occur
interstratified in these sections. The ooze layers, whichrange in thickness from 10 to 50 cm, commonly show
lithologic mottling and disturbed lamination resulting fromextensive burrowing. Nannofossil content ranges from 50%
to 90% in the ooze layers with undifferentiated clay
(10%-50%), Radiolaria (2%-7%), foraminifera (l%-5%),
diatoms (0%-3%), and terrigenous silt (l%-5%) comprising
the remainder.

SITE 218
TABLE 1
Coring Summary, Hole 218

Core

Date
(Mar)

1

1

2

1

3

1

4

1

5

2

6

2

7

2

8

2

9

2

10

2

11

2

12

2

13

2

14

2

15

2

16

2

17

3

18

3

19

3

20

3

21

3

22

3

23

3

24

3

25

3

26

3

27

4

Time

Depth fromDrill Floor(m)

Depth Below
Sea Floor
(m)

1930
2040

3759.0-3763.0
3763.0-3772.5

0-4.0
4.0-13.5

2200
2345
0140
0325
0519
0726
0915
1115
1314
1525
1735
2005
2215
2334
0106
0221
0336
0446
0730
1005
1235
1513
1730
2230
0120

3772.5-3782.0
3800.5-3810.0
3829.0-3838.5
3867.0-3876.5
3905.0-3914.5
3943.0-3952.5
3981.0-3990.5
4019.0-4028.5
4057.0-4066.5
4095.0-4104.5
4133.0-4142.5
4171.0-4180.5
4209.0-4218.5
4218.5-4228.0
4228.0-4237.5
4237.5-4247.0
4247.0-4256.5
4256.5-4266.0
4294.5-4304.0
4332.5-4342.0
4370.5-4380.0
4408.5-4418.0
4446.5-4456.0
4484.5-4494.0
4522.5-4532.0

13.5-23.0
41.5-51.0
70.0-79.5
108.0-117.5
146.0-155.5
184.0-193.5
222.0-231.5
260.0-269.5
298.0-307.5
336.0-345.5
374.0-383.5
412.0-421.5
450.0-459.5
459.5-469.0
469.0-478.5
478.5-488.0
488.0-497.5
497.5-507.0
535.5-545.0
573.5-583.0
611.5-621.0
649.5-659.0
687.5-697.0
725.5-735.0
763.5-773.0

TotalsRecovered(m)

Recovery
<%)

4.0

1.5

37

9.5

8.1

85

9.5

2.4

25

Cored
(m)

-

9.5

2.3

24

9.5

4.2

44

9.5

2.0

21

9.5

0.1

1

9.5

4.2

44

9.5

0.6

6

9.5

0.9

10

9.5

1.8

19

9.5

0.3

3

9.5

2.4

25

9.5

0.8

8

9.5

1.3

14

9.5

1.8

19

9.5

3.3

35

9.5

1.1

12

9.5

2.0

21

9.5

1.2

13

9.5

2.9

30

9.5

2.9

30

9.5

3.0

31

9.5

2.1

22

9.5

1.7

18

9.5

2.2

23

9.5

2.3

24

251.0

59.4

24

Note: Echo sounding depth (to drill floor) = 3737 meters; drill pipe length to bottom = 3759
meters.

Units 4, 6, 8 (Cores 9-12,17-22, 24-27)
These units differ from the previous (Units 3, 5, 7)
primarily in their greater abundance of clean silt and sandy
silt layers and the relative paucity of nannofossil ooze. Unit
4 is characterized by successive beds of clean silt, sandy silt
and silty, very fine sand the order of 20 to 60 cm thick.
Grading is apparent in some beds, but others appear
homogeneous. The minor layers of silty clay and clayey silt
which occur in this unit commonly contain thin clean silt
laminations. Units 6 and 8 differ from the above in thatlamination becomes typical. Layers (beds?) up to 40 cm
thick which are predominantly either clean silt or sandy silt
are apparent; however, these almost invariably exhibit
laminations of sandy silt, silt, clayey silt, and silty clay atscales ranging from a few millimeters up to several
centimeters. Grading still is apparent in many of the beds,
superimposed on the lamination. In terms of composition,
the silts and sands appear similar to those of Unit 2; quartz

and feldspar predominate (80% to 90%), with mica, calcite,
heavy minerals, and rock fragments constituting most of
the remainder.
General Observations on Sedimentary Textures andStructures

In the upper section (down to about Core 12) the silty
sand and sandy silt beds are thicker than below (up to 50cm), poorly sorted, and show clear grading. The silt-sizedgrains are usually angular, but some sand grains aresubrounded. In places (e.g., Core 10) some of these graded
beds have sharp lower and upper contacts, suggesting someerosion of earlier beds prior to or during the deposition ofyounger beds. Some sandy silt and clayey silt laminations
were seen, but their distribution is sporadic.
In the middle section (Cores 13 to 19) the sandy beds
become thinner. Interbeds are commonly only 5 cm thick,and in some instances sandy silt laminae less than 1 cm

327

SITE 218
8°00.4'N 86°17.0'E
3759m

Silt andSilty Sand

21 6
ClayeySilt and
Nanno Ooze

Silt andSilty Sand

6°-

85°

~~

86°

87 C
ClayeyS1It and
Nanno Ooze

Figure 1. Bathymetry in vicinity of Site 218.
thick begin to appear with a certain regularity. Some
well-sorted thin silt laminae also appear. The most distinctive feature of this section is the presence of semi-indurated
pelagic beds of nannofossil chalk, e.g., a 65-cm-thick bed inCore 18 and a 40-cm-thick one in Core 19. These chalks
show an intense degree of burrowing and mixing activity bybottom dwelling organisms. The following structures arepresent in abundance: burrows, mottling, worm tubes, andfaecal pellets. Also present, but far less commonly, werestructures of a nonorganic origin such as lamination and in
two places minor folding. Rare sediment intraclasts werealso seen in this middle section.
The lower section (Cores 20 to 27) is distinguished by its
well-developed cyclicity of sedimentary features. Somewhat
thinner (<15 cm) and finer-grained graded sandy silt beds
occur with regularity. Some laminae of clean silt occur both
singly and as multiples up to 2 cm thick. A few zones ofcross-lamination of this silt were also observed. The
remainder of the interval is typically clayey silt. However,
one of the most characteristic features of this section is theoccurrence of darker laminae (<l mm thick) of more
clay-rich silt (extremely fine grained) at regular intervals
with an average spacing of about 2 cm. This clear pattern issuperimposed on all other gross sedimentary structureseven throughout graded sandy silt beds!
CHEMICAL PROPERTIES

Twenty samples were collected and squeezed for interstitial water at this site. This hole was the deepest
penetration into the sediment on Leg 22, and these samples
provide excellent coverage from 4 to 773 meters. While
recoveries were comparatively low, 10-cm minicores were328

Laminated
Silt and
Nanno Ooze

T.D.

773 m; 27 cores

Figure 2. Lithologic units at Site 217.
obtained in most instances. In the other cases smaller
portions were obtained either by removing loose lumps
from the top of the first section or by obtaining some ofthe sediment removed from the core catcher. Four samples
from Cores 2, 3, 5, and 11 were soft enough to permit
punch-in pH measurements. Eighteen 20-cm minicores were

SITE 218

BIOSTRATIGRAPHIC SUMMARYS

GeneralThe sediments drilled at Site 218 are entirely of Neogene
age ranging from the late Pleistocene-Holocene Emiliania
huxleyi Zone to the middle Miocene Catinaster coalitus
Zone at the base of Core 26. Datable calcareous fossils,
either nannofossils or foraminifera or both, were recoveredfrom all cores. Radiolaria were recovered only in Core 1.
The sediments consist chiefly of detrital material and thishas diluted the normal pelagic constituents throughout
most of the section, although a large proportion of pelagic
constituents in some part of the section indicates that for
certain short periods pelagic sedimentation dominated. The
preservation is uneven, generally poorest in coarser sediments, and best in layers of pelagic ooze or fine detrital
sediments.

300

Figure 3. Pore water pH data.

taken and frozen for the organic geochemistry program.
Samples for this program were obtained from every core
having a recovery of one section or more (150 cm).
All four punch-in measurements were made on minicores
which were precooled in an ice bath and allowed to warm
to room temperature. Special care was taken in making
flow-through pH measurements to wait until a constantvalue was reached for both pore water samples and buffers.
In some instances, 20 to 30 minutes were required.
Temperature coefficients and pH value, obtained by bothmethods and corrected to pore water temperatures, aregiven below:
Sample

Slope
mv/°C

pH
(punch-in)pH(flow-through)Temperature

218-2^
218-3-2
218-5-2
218-11-2

0.88
0.68
1.29
1.57

7.25
7.44
7.17
7.12

7.97
7.91
7.79
7.60

24.0
26.0
26.2
25.0

Pore water pH values (Figure 3), with a few exceptions,appear to be systematically decreasing with depth to ~500
meters, then increasing between 500 and 773 meters(maximum depth). The most notable departure is the pH
6.5 recorded for the ~615-meter depth. A cursory inspection of the lithologic description for this core provided noclues to this behavior. Possibly, this is an artifact of sample
handling as it was necessary to squeeze this sediment anunusually long time. However, a loss of CO2 resulting in ahigher pH would seem more likely if squeezing had altered
the sample.

Foraminifera
The foraminiferal content of core-catcher samples variedmarkedly through the section, and the main factor controlling this variation presumably is the sampling position
within a turbidite-pelagic unit. Also, however, there isevidence of transport and redeposition. Shallow water
benthonics {Ammonia beccarii, Pseudorotalia aff.
schroeteriana, Elphidium) are found sporadically andalways rarely down to Core 27. Deeper water benthonics
give no evidence on this point. The distribution andnumbers of planktonic specimens indicate mixing. Thus, inthe relatively rich assemblages in Core 1 ( 1 , 24-26 cm;CC)
the robust, keeled Globorotalia are strongly corroded oreven eaten away except for the keel, whereas some of themore delicate tests are preserved quite well; there are also
staining and other preservational clues to allochthonous
derivation. More obvious mixing is seen in the presence ofearly Tertiary planktonic species in Cores 8 and 9. In the
numerous core-catcher samples where only scattered specimens occur, it can be assumed that they are redepositedand that any age is maximum rather than actual.
Core 1: Zone N.23,late Quaternary.
Cores 2 to 7: Evidence for Zone N.23.
Core 8: Pliocene species present, but taken as Pleistocene on rare, early G. truncatulinoides.
Core 9: Paleocene species.
Core 10: Pliocene; Core 11: Zone N.19 or N.20,
Pliocene.
Core 12: ?;Core 13: upper Miocene.
Core 14: Core catcher, no planktonics; extended barrel,
upper Miocene "pelagic," probably Zone N.16.
Core 15: No useful data; Core 16: Zone N.16, upper
Miocene.
Cores 17 to 27: Planktonics rare to absent, of Miocene
aspect. A maximum age of middle Miocene (Zone N.I 3) forCore 26.
Nannofossils
Some calcareous nannofossils were recovered fromthroughout the interval cored at Site 218, and these
indicate an age range from the late Pleistocene-Holocene at

329

SITE 218

the top of the section to late middle Miocene at thebottom.
The Pleistocene extends from Cores 1 through 8. Core 9yielded only a few reworked Tertiary forms, and Core 10
contains early Pliocene species. The early Pliocene assemblage continues through Core 11, but Core 12 is assignable
to the late Miocene. The late Miocene continues throughCore 23 possibly Core 24 (the latter yielded no age
diagnostic nannofossils). The section terminates in the late
middle Miocene with Cores 25 through 27.
The nannofossil assemblages are generally sparse, except
in pockets or isolated layers where small amounts of ooze
were recovered. The preservation in general is not very
good, most specimens being not more than large fragments.
Reworked Tertiary and Cretaceous specimens are notuncommon but do by no means dominate the nannofossil
assemblages, and, consequently, the age determinations
made on nannofossils at this site can be considered quite
reliable.
Radiolaria

Radiolaria at Site 218 are common and well preserved
only in the topmost part of Core 1 (Sample 218-1-1, 24-26cm). This sample contains well-preserved specimens of
Theocorythium trachelium, Euchitonia elegans, Pterocanium praetexum, Amphirhopalum ypsilon, Collosphaera
tuberosa, and Ommatartus tetrathalamus, indicating a
Quaternary age. Within Core 1 there is a transition frompelagic, mostly biogenous material near the top of the core
to terrigenous debris at the base. This transition may
coincide approximately with the Holocene/Pleistocene
boundary, corresponding to a transition from predominantly turbidite deposition to predominantly pelagic deposition. At the base of Core 1 (Sample 218-1, CC) a few
Quaternary Radiolaria are present, but the degree ofpreservation has declined markedly. Below Core 1 there arescattered light-colored, carbonate-rich layers within a predominantly turbidite unit. Radiolaria are absent in all
samples obtained from the turbidite, and a few poorly
preserved radiolarian fragments are present in some samples(e.g., 218-18-1, 60-62 cm) from the carbonate-rich layers.
These fragments are insufficient in number and in preservation for age assignments.
CORRELATION OF REFLECTION PROFILEAND STRATIGRAPHIC COLUMN

Site 218 is situated in a typically flat area in the central
Bengal Fan in a water depth of 3749 meters. The site issituated between two large, leveed fan valleys, the nearestof which lies about 5 miles away.
The seismic reflection profile shows a unit at least 1 sec
thick of parallel, closely spaced reflecting horizons which
presumably represent turbidite sediments and interbedded
pelagics (Figure 4). These reflectors become less distinct
below 1 sec, but may extend down to 1.5 sec. A distinct
reflector occurs at 1.5 sec, flat-lying below the region of thesite, and onlapping a basement protuberance 20 miles tothe northwest on the Argo CIRCE III seismic record.
Sediments recovered from the surface down to a total
depth of 773 meters are dominantly turbidite sandy silts
and clayey silts in graded beds up to 70 cm thick,330

interbedded with clay nannofossil ooze layers. No obvious
correlations exist between these and reflectors in theseismic profile.
SUMMARY AND CONCLUSIONS

Situated in the central Bengal Abyssal Fan in 3749
meters of water, Site 218 was drilled in a turbidite
sedimentary sequence. The actual drilling area is on a
typically flat portion of the fan, approximately 18 km westof a major fan valley, where the seismic reflection profile of
the area indicates a sedimentary sequence in excess of 2 sec
thickness.
The stratigraphic column was mostly spot cored at about
20-meter intervals to a total depth of 773 meters. The
entire sequence, ranging in age from upper Quaternary to
middle Miocene is composed of interbedded clean silts,
sandy silts, clayey silts, and silty clays of turbidite origin
with occasional layers of clay-rich nannofossil ooze. This
rules out the possibility that the section at this site could be
pelagic as was encountered at Site 217. Discrete sedimentary units are not recognizable in most of the section;
however, zones of relatively coarse terrigenous sediments
appear to alternate with zones of relatively fine terrigenous
materials interbedded with nannofossil ooze layers (Figure5). These zones indicate pulsating turbidite deposition at
the site. Four time intervals, one in the middle Miocene,
two in the upper Miocene-lower Pliocene, and one in the
Pleistocene, are characterized by relative abundance ofcoarse sediment and reflect periods of more intense
turbidity current activity. These active periods wereseparated by lulls during which principally finer silts andclays were deposited. Terrigenous sedimentation rates wereapparently lower at these times; hence, pelagic components
formulate a significant proportion of the deposited
sequence. Evidence of intense burrowing activity bybottom organisms is common in and near the pelagic
segments of the cores, supporting the contention of lower
depositional rates.
Variations in the frequency and intensity of turbidity
currents to any one site such as this could be effected by atleast three obvious mechanisms: (1) shifting of the maincurrent action to channel systems at varying distances fromthe site; (2) climatic variations and associated sea-levelchanges which affect the rate of sediment input tosubmarine valleys feeding the fan; (3) tectonic activity in
the Himalayas and attendant erosive output of the GangesBrahmaputra River system which feeds sediment to the fanfrom the north (Curray and Moore, 1971). Relating theapparent pulses shown in Figure 5 to the above mechanisms
is perhaps premature considering the sparseness of the data;
nevertheless, some speculation seems appropriate.
The uppermost Pleistocene pulse, wherein occur the
sandiest and coarsest (up to medium sand) of the sediments
drilled, seems most logically attributable to influx ofterrigenous material during maximum glaciation and lowering of sea level in the late Pleistocene. Uplift andconsequent increased erosion due to late Pliocene andPleistocene orogeny in the Himalayas presumably aided in
producing this intense turbidite phase as proposed byCurray and Moore (1971). Abrupt drop-off of turbidity

SITE 218

SITE 218

600-

T.D. 773 m

Nautical Miles

10
i

Figure 4. Correlation of reflection profile and stratigraphic column at Site 218.

331

SITE 218

10

0

.

. % Coarse Terrigenous

×× % Pelagic
20

30

40
— ' •

50

—

60
!

'

70

— — * " ' —

80
L

90
'

CORE
NO
"

100
*

;

AGE

o

" ~ ~ ~ ~ ~ ~ - - ~Pulse 1
;X

6

" " ^

7
•8

200
^ ^

9
^~~~~~^^^

;

-10

JUU>

^ . /

300

-11 EARLY PLIOCENE^~J ~ - ~ - ^Pulse 2
.12

<

^

.5
QUATERNARY

100

-13

400

• 14
:1516

~ £ ^ "

500

Tgj18

"

*

•

×—,
600

-21

_______—!
=r^JJ'

Pulse 3•—______^
»
\
a

22
.23
24

"~~

700

UPPER MIOCENE

1-25
Pulse 4.26

MIDDLE MIOCENE-27

Figure 5. Distribution of sediment types with depth.
current activity, indicated by the predominance of nannofossil ooze in the upper 8 meters of the sediment column,

332

probably relates primarily to deglaciation and submergenceduring the Holocene, but may also reflect shifting of
maximum sediment dispersal to a more remote channel
system.
Interpretation of the older pulses is more tenuous. The
youngest of these may reflect late-Miocene orogeny in the
Himalayas as suggested by Curray and Moore (1971), theolder pulses being accounted for by the vagaries of thechannel system.
Heavy minerals examined from Site 218 cores (Chapter38) indicate derivation of these sediments from a complex
acid igneous and metamorphic terrane and thus support theinterpretation of Curray and Moore (1971) which stipulates
the Himalayas as the principal source.
Stratigraphic equivalents to onlapped beds marking theupper unconformity of Curray and Moore (1971) were
found to be late Miocene where sampled in Site 218. These
strata lie near the base of a section of silt and silty sand(pulse number 2 of the series) which could reflect orogeny
in the Himalayas coeval to that forming the mid fan upper
unconformity.

REFERENCE
Curray, J. R. and Moore, D. G., 1971. Growth of theBengal deep-sea fan and denudation in the Himalayas:
Geol. Soc. Am., v. 82, p. 563-572.

Site218

Cored Interval:0-4.0 m

HoleCore 2

Cored Interval:4-l3.5

FOSSILCHARACTERFOSSILCHARACTER

LITHOLOGIC DESCRIPTION

LITHOLOGIC DESCRIPTION

J

.

-

^ r O xion I
contact-burrowing

IRON OXIDE RICH NANNO OOZEo l i v e gray (5Y5/4)
NannosOpaques ( i r o n oxide)
ForamsRads
CalciteFeldsparOther:
Diatoms
Sponge spic.
Silicoflag.

CALCITE FORAM CLAY DIATOM RICH
64%
11%

7%

dark olive gray
(5Y3/2)5%r.
z%light gray (5Y6/1)
o l i v e gray (5Y4/2)
sand, lamin.

dark greenish
gray (5GY4/1)
CLAY SILT RICH NANNO OOZF
NannosFeidsparOpaques
U n d i f f . clay
Carb. fragments
ForamsOther:
Diatoms
Rads
Sponge s p i c .

CoreCatcher

Texture o f TERRIGENOUS
Sand
Silt
Clay

l i g h t gray (5Y6/1)
dark greenish gray
(5G4/1)l i g h t o l i v e gray
(5Y6/2)light gray (5Y7/1)

11%
5%
Z%
1%

interbedded
light gray (5Y7/1)
olive gray (5Y4/2)
dark gray (5Y4/1)
olive gray (5Y4/2)

5%
40%
-

gradational

Explanatory notes in Chapter 1

o l i v e gray (5Y4/2)

o l i v e gray (5Y4/2)

dark o l i v e gray
(5Y3/2)olive gray (5Y4/2)

dark o l i v e grayo l i v e gray (5Y4/2)

Explanatory notes in Chapter 1mNannos
Siliceous biog.
Terrigenous
ForamsCalcite
Other

10%
1%

SILT RICH NANNO OOZE
NannosTerrigenous
CalciteOther:
Micronodules
Forams
Glass
Silt
Clay

70-8058
20-30%

78%
37.
2%

FeldsparClay
Mica
Heavies
Other:
CalciteChlorit<

FORAM CLAY RICH NANNO OOZE
NannosClay
ForamsOther:
CalciteRads
Diatoms
Sponge spic.
Silicoflag.

60%
25%
5%
7%

70%
π

?:•

10%
10%

Mainly FORAM DIATOM CLAY RICH NANNOOOZE with layers of less biogenous
sections
CLAYEY SILT
Silt 65% Feldspar
Clay 35% Clay
HeaviesNannosCalcite
Other

59%
30%

5: .
3%

SANDY SILT (graded)
Sand
Silt
Clay

top
bottom
25% 40%60% 50%15% 10%FeldsparQuartzRock Fragments
Heavies
CalciteMica
Other:
green b a l l s !
CLAYEY SILTS i l t 55% Feldspar
Clay 45% Clay
Opaques
CalciteNannos

50%
39%
5%
3:.3%

DEFORMATIONJMETERSSECTIONPRES.

AßUND.

ZONEFOSSILAGE

LITHOLOGY

LITHO.SAMPLEJ

Cored Interval:13.5-23.0 m

FOSSILCHARACTER

J

Hole

I

|

Site 218

Cored Interval:70.0-79.5 m
FOSSILCHARACTER
LITHOLOGIC DESCRIPTION

LITHOLOGIC DESCRIPTION

EMPTY

1
1 -74
1
1
1 -133>

1

i I I I 1 I I i I 1 I I I I

PLEISTOCENE

1.0-

2

ci

__EMPJ Y _ _very dark-gray (5Y3/1)
dark graysilt

dark o l i v e™
(cl‰gray yan/á)clay

interlaminatedvery dark gray (5Y3/1) slightly

Sand 15%
S i l t 75%

FeldsparQuartzfragments

Q%

Rock

\

1
—
1
1
very dark
1-130gray (5Y3/1)
1

\
^ILT
/
/
Sand T0%
S i l t 70%
Clay 20%

1PCore 4

Gephyrocapsa oceanica Zone

1

2

P

Core
Catcher

DEFORMATION

LITHOLOGY

LITHO.SAMPLE

0u_

PLEISTOCENE

NANNO RICH CLAYEY SILTS i l t 65% Feldspar
Clay 35% Nannos
Clay
CHLORITE RICH SILT Heavies
mottles 1of (5G4/1) Calcite
up to '5'% c h l o r i t e Other
QuartzOpaquesdark gray(5Y4/1)

dark greenish
gray (5GY4/1)

dark gray(5Y4/1)

Cored I n t e r v a l : 4 1 . 5 - 5 1 . 0 m! 1 1 1 1 M 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

ZONE

AGE

F 1SSI L
CHA RAC1 ER

R
R

2- 6%
10-20%
10-15%Catcher

Hole

F
N

Mica
Clay
Heavies
Opaques
Hornblende
EpidoteZirconSpheneChlorite

53-74%
1-2%

T r . _ 2%

as above

Core

METERS

Site 218R
R

SECTIONF
N

Sand 55% Feldspar
Silt 45% Mica
Heavies
Opaques
Others:SANDY CLAYEY SILT
Zircondark gray (5Y3/1) CLAYEY SILT
GarnetTourmalirdark gray
CLAYEY SILT
Sphene(5Y4/1)
Epidote65%

NANNO RICH SILTS i l t 80%
Clay 20%NANNO 00;ZE
NannosRads
Clay
Diatoms
CalciteFeldsparSponge spic.

gray (5Y5/1)
LITHOLOGIC DESCRIPTIONCoreCatcher

EMPTY

mottles of CLAY RICH NANNO OOZE

• ,

CD•

•

-118
148
GEOCHEMSAMPLE

dark gray(5Y4/1)

1

S i l t 90%
Clay 1 0 % _ ^ ^sandy s i l tlaminations(very darkgray, 5Y3/1)^~~~^~~—SUJ (graded)/Feldspar/
Quartz
/
Mica
/
Clay
/
Calcite/Heavies:
Sand 7%Opaques
S i l t 83%
Othersdark gray(5Y4/2)

C1a

1
1
1
1
dark
1 -105 — verygray (5Y3/1)

Cored Interval:108.0-117.5 m
FOSSILCHARACTER*

LITHOLOGIC DESCRIPTION
70%
1%
5%
8%
3%
12%
5%
7%

1 M
1

laminations
as abovelight gray
(5Y6/1)'dark gray (5Y4/1)" very dark gray—(5Y3/1)

Explanatory notes in Chapter 1gray (5Y5/1)
light gray (5Y6/1)
very dark graylight gray (5Y6/1)
olive gray (5Y4/2)
Core
Catcher

Explanatory notes in Chapter 1

76%
7%
7%
3%
3%
2%
1%

66?
3%
302

43':.
30,
15?.
5%
4%
3.

P
F

Core
Catcher<CofCore Catcher sample
very dark gray (5Y3/1)

1

?

Hole

Core 8

F
N

R
R

P

LITHOLOGIC DESCRIPTION

EMPTY

II

S i l t 703! Feldspar
80%
Clay 30% Opaques
3%
Heavies
7%
Calcite5%
Others:5%
QuartzMica
NannosRads
Sponge s p i c .

DEFORMATION |u.

LITHOLOGY

LITHO.SAMPLEQMETERSZONEAGELITHOLOGIC DESCRIPTION

Cored Interval:222.0-231.5 m

|

1

1

1

F )SSI L
CHA RAC FERSECTION

R
F

Q_

DEFORMATION |FN

LITHOLOGY

LITHO.SAMPLE |

ZONE

AGE

1

Cored Interval;146.0-155.5 m

1 1 1 1 | 1 1 1 1 | 1 1

PLEISTOCENEoσu_

METERS

Core 7F )SSI L
CHA RAC FERSECTIONHole

1 -110 '—1
1 -130

dark gray(5Y4/1)

1(•ü>n/•nk°'J/l;

9l ay

Sand
Silt
Clay

40%
50%
2%

FeldsparMica
Quartz84%
7%
1%

Calcite

3%

Rock

"

fragments
Heavies
HornblendeZirconEpidoteCore
Catcher

CLAYEY SILT
Finely laminatedS i l t 75%
FeldsparClay 25%
Clay
Opaques
CalciteHeavies

Cored Interval.184.0-193.5

FOSSILCHARACTER
LITHOLOGIC DESCRIPTION

60%
25%
8%
5%
2%

very darkgray (5Y3/1)
gray (5Y4/1)

2%
very darkgray (5Y3/1)' light gray
(5Y7/1)
GEOCHEMSAMPLECore
Catcher
Explanatory notes in Chapter 1gray (5Y4/1)

DEFORMATION

EMPTY
-7

1

R

P

Core
Catcher

LITHOLOGIC DESCRIPTIONSILTY CLAYw i t h laminations (<l mm)
S I L T
(5Y6/1)

dark αr»v
?‰T

o f

-76
-85 _ g r a y ( 5 Y 5 / l )o l i v e gray-118 — (5Y4/2)
dark gray(5Y4/2)

1.0-

3%(dark gray 2.5YN4)with interbeds of SJüJ ( I t . gray 5Y6/1)

LITHOLOGY

LITHO.SAMPLE

METERS

s.

0.5-

F
N

CLAY RICH NANNO OOZEGlass (acidicintermediate)
FeldsparCalciteHeavies
Mica

ZONE

AGE

gray (5Y4/1)

—

o

o

EARLY PLIOCENE——

CLAY RICH NANNO OOZE
NannosCalciteClay
ForamsRads
Heavies

SECTION

Cored Interval;260.0-269.5 m
FOSSI LCHA RAC ER

SILTY NANNO OOZE
Nannos
S i l t and Clay
CalciteO t h e r s

3%

SILT ?
Sand 70% Feldspar 87%
S i l t 25% Heavies
7%
Mica
5%
Calcite1%
Graded SAND ÷ CLAYEY SILT
contacts
S sharp
G gradational

Explanatory notes in Chapter 1

60%
32%
5%

S i l t
C l a

3 M

* 6M
S i l t 97%
Clay 3%

Core 11

Cored Interval:374.0-383.5 m

Cored Interval:298.0-307.5 m
FOSSILCHARACTERFOSSILCHARACTER

LITHOLOGIC DESCRIPTION

LITHOLOGIC DESCRIPTIONNANNO CLAY and
CLAY RICH NANNO OOZE

SAND
s i l t y near top

gray (5Y6/1)
very dark gray
(5Y3/1)light gray
(5Y6/1)gray (5Y5/1)

GEOCHEMSAMPLEolive gray (5Y4/1)

Silt 60% Feldspar
Sand 30% Heavies
Clay 10% Mica

dark gray (5Y4/1)~

CalciteMicronodules

dark gray(2.5YN/4)

NANNO CLAY
with layers of nanno ooze
and clayey s i l t
Clay50%
Nannos43%
Calcite5%
Others:2%
OpaquesHeavies
Feldspar

90*
S%

n
1%
2%

gray (5Y5/1)

Terrig. frac.
S i l t 60% Nannos
Clay 40% Feldspar
ForamsClay
CalciteOpaques
Othersgray (2.5Y5/1)+ gradingCore
Catcher

SANDY
Sand 20%
S i l t 75%
Clay 5%g r a y i s h o l i v e green (5GY3/2)
Nannos69%
Clay
25%
Calcite6%(5Y5/1)

with occasional lamination andmottle o f clean s i l t and sandy
silt

SANDY SILT
with very f i n e sandlaminae at base
Hole

LITHOLOGY

DEFORMATION

Cored Interval:336.0-345.5 m
LITHO.SAMPLE

METERS

Corel 2
SECTIONABUND.

PRES.

ZONE
Discoaster
quinqueramus Zone

Hole
FKSIL
CHA RACTERFOSSILAGE
LATE MIOCENE

Site 218

Corel4

Cored Interval:412.0-421.5 m

FOSSILCHARACTER
LITHOLOGIC DESCRIPTION

LITHOLOGIC DESCRIPTIONSAND ( g r a y 5Y4/1) g r a d i n g
up t o SILTY CLAY (2.5YN/4)

0.5-

1

EMPTY
.sharp contact
dark gray (2.5YN/4)£.,_„„..._., J
F
N

R
F

P
F

Core
Catcher ..".SILT ?'..'

138
-141

— d a r k gray (2.5YN/4)

CLAY with pockets o f
s i l t and very fine sandCore
Catchergray (5Y5/1)
SILTY SAND grading upward to CLAYEY SILT
sandy silt
Feldspar78%
Calcite
6%
Mica
5%
Heavies5%
Opaques3%
Chlorite
3%

FeldsparCalciteHeavies
Others:Opaques
Rock fragments
Micainterlaminated £ H J andgray (2.5YN/6, 5Y5/1)
mixed sand and clay
Extended core b a r r e l :Explanatory notes in Chapter 1

mottled dark greenish gray (5GY4/1)
and l i g h t gray (N7).
CLAYEY SILT-SILTY CLAYo l i v e gray (5Y4/1)

Explanatory notes in Chapter 1

80%
15%
3%

Site218

Cored I n t e r v a l ; 4 5 0 . 0 - 4 5 9 . 5 m

HoleCorel7

Cored I n t e r v a l : 4 6 9 . 0 - 4 7 8 . 5 m

FOSSILFOSSILCHARACTER

CHARACTER

LITHOLOGIC DESCRIPTION

dark gray
5YN/4

LITHOLOGIC DESCRIPTION

CLAYEY SILT (very dark gray, 5Y3/1)
with lainations of clean silt(light gray 5Y7/1) and interbeds
of sandy silt (5Y3/1)

CLAYEY SILT-SILTY CLAY
with sandy s i l t laminations
mainly at i n t e r v a l s o f 5-10 cm.
prominent SANDY SILT
layers grade upward
to CLAYEY SILT-SILTY CLAY

Sand 353!
S i l t 65%

S i l t 70%
Clay 30%

Core
Catcher
FeidsparCalciteHeavies
Others:Mica
Iron oxide
Clay
CLAYEY SILT-SILTY CLAY (as above)

EMPTY

**£

F
N

V
F

F
F

Core
Catcher

Explanatory notes in Chapter 1• - •- • - • • - ~ • •DEFORMATION
LITHO.SAMPLEo

LITHOLOGY

—
1 —55
1 -65
1
1

αrav
5Y6/1
5Y5/1
b T b / las topdark gray
2-5YN/4

SILTS
Sand 35% Feldspar
S i l t 60% C a l c i t e
HeaviesO t h"s:
M i c aOpaques
Rock fragments
Clay
CLAY RICH NANNO OOZE
Nannos45%
clay
10%
Calcite3%
Others:3%
ForamsOpaquesMica
I r o n oxide

82%
5%
4%
8*

-

1
1.02
F
N

R
F

F
F

LITHOLOGIC DESCRIPTION

VOID

0.5üülilili

AS ABOVE ?

CHA RAC1 ER

dark gray (2.5YN/4)

SJJJ

dark gray

CLAY RICH NANNO OOZE
burrow m o t t l e d , feacal p e l l e t s ,laminae w i t h folded s t r u c t u r e ,Clay f r a c t l o n
increases w i t h depth.

-67
"

i

i

"

Core

Catcher

Explanatory notes in Chapter 1

S i l t 90%
Clay 10%

Cored Interval:478.5-488

F DSSI L

o

EMPTY

2

Corelδ

CLAYEY SILT (dark gray 2.5YN/4)
w i t h SANDY SILT (gray 2.5YN/5)
laminations and i n t e r b e d s .
S i l t s 3-5 cm t h i c k , spaced a t 10 cm
i n t e r v a l s . Sharp base to sandy beds,
gradational tops.

1.0-

METERS

1

SECTION

Discoaster neohamatus Zone

LATE MIOCENE

0.5-

LITHOLOGIC DESCRIPTION

ZONE

I 1

LITHOLOGY

SJil (very dark gray 5Y3/1)
with laminations of clayey s i l t .
Clay content decreases toward
base and sandy s i l t layers occur.

AGE

ü_

Sand 20%
Silt 73%
Clay 7%

LATE MIOCENEo$ocontorted lamination

83-92%
2 - 1%
3 - 5%SANDY SILT
poorly sorted
subangular grainsvery fineCored Interval;459.5-469.0 m

DEFORMATION
LITHO.SAMPLE

ZONE

AGE

FOSSI LZW RAC PERMETERS

Corel6

SECTION

Hole

Sand 1%
Silt 94%
Clay 5%70-80%
10-15%
2- 7%
8%Feldspar
Heavies
CalciteOthers:NannosChlorite
Opaques

=^•J

SILT

NannosCalciteForamsOpaques
Clay up t o

80%
3%
1%
1%
15%

Hole

Core22

Cored I n t e r v a l : 5 7 3 . 5 - 5 8 3 m
DEFORMATION |S i t e 218

Cored I n t e r v a l : A 88-497.5 m

LITHOLOGY

1.0-

S i t e 218

Holeverv dark αrav
very uαr K. yrαy(5Y3/1) abundantly
laminated

CLAYEY SILT
grading t ocnunv CTI T
SANDY_SILJ

clayey s i l t grading tosandy s i l t
clayey s i l t abundantly laminated— silt<DEFORMATIONMETERSSECTION

LITHOLOGY

S i l t 80%
Clay 20%
FeldsparMl C3

H e a v i e s

89%
\7o
ffl

0.5-

1

dark αrav f? 5YN41
dark gray {.d.i>wn)

FF

1 1 1 1 | 1 1 1 1 | 1 1 1 1

LATE MIOCENE

1.0-

R
F

Core

Catcher

Explanatory notes in Chapter 1

METERS1 1 1 1 1 1 1 1 1 1 1

DEFORMATIONMETERSSECTIONPRES.

FOSSILABUND.

LITHOLOGY

SILJ

laminated (1-2 mm t h i c k ) o f
Y SILT andsandy s i l t (=10 mm t h i c k )CLAYERegularly interbedded
laminae are 1-2 cm a p a r t .

•120

S i l t 90%
Sand 5%
Clay 5%SILJ

FeidsparCalciteFe-oxideOpaquesHeavies

84%
10%
2%
2%
2%

100

1.0-

LITHOLOGIC DESCRIPTION

very dark gray (5Y3/1) CLAYEY SILT
grading to
SANDY SILT
CLAYEY SILT
grading to
SANDY SILT
CLAYEY SILT abundantly laminated
w i t h SANDY SILT

2

R
F

F
F

dusky yellow green (5GY5/2)
-i_

_i_

_

100

-C/C
Core
Catcher

Explanatory notes in Chapter 1F
N

Cored Interval;611.5-621.0 m

1FN

LITHOLOGIC DESCRIPTION

VOID

2

SILT interbedded w i t h f i n e sand (5-10 rm t h i c k ) .

Core 23

Cored Interval:535.5-545 m

o-60

FOSSILCHARACTER

ZONE

80%
6%
2%
10%
1%

-

0.5-

-40

••.j~i v^vr;;.:."-",F KSI LCHA RACl ER

dark gray (2.5YN4) SILT
interlaminated with
FINE SAND and CLAYEY SILT

LITHOLOGIC DESCRIPTION

LITHO.SAMPLEHoleSECTIONZONE

LATE MIOCENE
1

SANDY SILT
Sand 25% Feldspar
S i l t 75% Rock clasts
Heavies
Opaques
CalciteCored Interval:497.5-507 m

1

ZONE

2

SJJLJ
laminated throughout

dark gray(2.5YN4)

0.5-

o
U_

AGE

DEFORMATION

~
140

VOID
LATE MIOCENE

LITHO.SAMPLE~abundantly laminatedzone FTNF SANDY SILTLu

Site 218

NANNO OOZE
mottled with large burrows—f—_

i I I I 1 I I I I 1 Iσ— SJLJ

Discoaster neohamatus Zone

ZONE

AGE

F 1SSI L
CH/i RAC ER

-50

1.0-

CLAY

AGE

1 1 1 1 1 1 1 1 1 1 1 1 I I

I 0 re 20

LITHOLOGIC DESCRIPTION

1
dark gray (2.5YN/4)

SILJ

METERS

Hole

0.5—

Core
Catcher

SECTIONS i t e 218

F
F

LITHOLOGY

CU

VOID

DEFORMATION

R
R

a:

o

1 1 1

LATE MIOCENE—

2

LITHOLOGIC DESCRIPTIONLATE MIOCENEo

1 1 II | 1 1 1 1 | 1 1 M

1FN

LITHOLOGYa.

F 1SSI L
CHA RAC PER

LITHO.SAMPLE<c

METERSoo

SECTIONZONEAGECHA RAC ER

LITHO.SAMPLE j

CorelSF )SSI L

LITHO.SAMPLE

Hole

1

Site 218

S i l t 73% Opaques
3%
Clay 27% Heavies
5%
Calcite7%
Feldspar 85%

HoleCore 26F OSSI L
CHf RAC rER
ZONE

AGE

LITHOLOGIC DESCRIPTION

2

Cored I n t e r v a l .725.5-735 m

LITHOLOGY

Q_

Sand 20%
Silt es%Claydusky yellow green(5GY5/2)Core
Catcher

LITHOLOGY

DEFORMATIONPRES.

ABUND.

ZONE
Discoaster neohamatus Zone

FOSSILAGE
MIDDLE MIOCENEDESCRIPTION

VOID

dark gray (2.5YN/4)

•°~

2

F

R

N

R

F

Core
Catcher

SILJ

silt

interbedded withsandy s i l t laminae andlayers,sandy s i l t

GEO.CHEM
SAMPLE__SandySi1t

Graded sequence of-86 = sandy s i l t— clayey s i l t
silt
sandy s i l t
silt
sandy s i l t— clayey s i l t
clayey s i l t

SANDY SILT

SANDY

SILT

Note - A pyrite rich silty zone
observed at about 80 cm
in Section 2.

Cored I n terval.687.5-697 m
Cored Interval:763.5-773 m

LITHO.SAMPLE

Core 25

FOSSILCHARACTER

METERSHoleSECTIONS i t e 218

LITHOLOGIC

1I I II 1 I I I I 1 I 1 I I

CLAYEY S1 J

Silt 65%
Clay 35%

Catinaster coalitus ZoneSANDY SIL1r
very dark gray (5Y3/1)
CLAYEY SHJ grading to— SANDY SIL [ very dark gray (5Y3/1)

MIDDLE MIOCENE

0.5—

DEFORMATIONS i t e 218

Cored Interval:649.5-659 m

LITHO.SAMPLE

Core24FOSSILCHARACTER

METERSHoleSECTION

Site218

LITHOLOGIC DESCRIPTIONFOSSILCHARACTER
LITHOLOGIC DESCRIPTION

0.5VOID

1

S i l t 65% Feldspar
Clay 35% Heavies
Mica
Opaques
CalciteSEQUENCE OFGRADED LAYERS

very dark gray (5Y3/1)
grading towards a

1.01
1
1
1
1
r .i r^. .\'.^~.. 1 -80

"ail

2

uij

-..

-144
F
N

R
R

F

Core
Catcherdark gray (2.5YN/4)

SJJJ
intermixed with CHALK

sandy s i l tclay r i c h chalk——

SILT interbeddedwith sandy s i l tlaminae
SILT

.
—

Core
Catcherclayey silt
sandy silt
clayey silt
sandy silt
clayey silt
sandy silt
clayey silt
sandy silt
clayey s i l t

Sand 30% Feldspar 77%
S i l t 60% C a l c i t e
15%Clay 10% Opaques 5%
Heavies2%
Mica

Explanatory notes in Chapter 1
CLAYEY SILT GRADED WITH SANDY SILT
Explanatory notes in Chapter 1

00

H
W
to

SITE 218

218-1-1
340

218-1-2

218-1-3

218-2-1

218-2-2

218-2-3

SITE 218

0 cm

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218-2-4

218-2-5

218-2-6

218-3-1

218-3-2

218-4-1
341

SITE 218

0 cm

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125

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218-4-2
342

218-5-1

218-5-2

218-5-3

218-6-1

218-6-2

SITE 218

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218-8-1

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218-9-1

218-10-1

218-11-1
343

SITE 218

218-11-2
344

218-12-1

218-13-1

218-13-2

218-14-1

218-15-1

SITE 218

_16_1

218-16-2

218-17-1

218-17-2

SITE 218

•0 cm

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218-19-1
346

218-19-2

218-20-1

218-21-1

218-21-2

218-22-1

SITE 218

0 cm

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50

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100

125

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218-22-2

218-23-1

218-23-2

218-24-1

218-24-2

218-25-1
347

SITE 218

0 cm

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100

125

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218-25-2
348

218-26-1

218-26-2

218-27-1

218-27-2