7. SITE 216
The Shipboard Scientific Party1

ABSTRACT
Site 216 was drilled on the crest of Ninetyeast Ridge near theequator, in a water depth of 2237 meters. The stratigraphic
column at this site, 457 meters thick, consists of an uppermost
Pleistocene to late Maastrichtian nannofossil ooze to chalk unit
which is glauconitic at the base and contains several chert
stringers. This is underlain by a late Maastrichtian shallow water
unit comprising micarb chalk, volcanic clay, and ash beds, in part
intensely bioturbated. This is underlain by scoriaceous andamygdalar chloritized basalt containing rare veinlets of native
copper. The stratigraphy resembles that of Site 214, 1300 km to
the south along the crest of Ninetyeast Ridge. The Cretaceous/
Tertiary boundary was cored and could be accurately identified
using nannofossils and foraminifera.
SITE DATA
Date Occupied:
216: 18 Feb 72 (2312)
216A: 21 Feb 72 (0330)
Date Departed:
216: 21 Feb 72 (0330)
216A: 21 Feb 72 (2315)
Time on Site:
216: 52 hours 18 minutes
216A: 19 hours 45 minutes
Position:lat 1°27.73'N
long90°12.48'E
Water Depth (to rig floor):
2262 meters (Echo sounding)
2247 meters (Drill pipe)
Penetration:
216: 477.5 meters
216A: 158.5 meters
Number of Holes: 2
Number of Cores:
216: 38
216A: 6

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.

Total Length of Cored Section:
216: 353 meters
216A: 57 meters
Total Core Recovered:
216: 170.8 meters
216A: 53.7 meters
Acoustic Basement:
Depth: 457 meters
Nature: Basalt
Age of Oldest Sediment:
216: Maastrichtian
216A: Middle Miocene
Basement: Basalt

BACKGROUND AND OBJECTIVESIn the original cruise plan we anticipated attempting only
seven sites. However, because of an unexpected absence ofdrilling problems we terminated Site 215 about 5 days
ahead of schedule and decided to drill another site. Three
possibilities were open: (1) a site on the ridge further norththan Site 215, (2) a site in the distinctive magnetic
anomalies to the west of Site 215, and (3) a distal fan site.
The third was rejected due to the difficulty of obtaining
clear sections of Curray and Moore (1971) W, Y, and O
sediments in the distal fan and because the site would
duplicate the two sites planned in the fan further to thenorth. The second site was rejected because it would
involve extra steaming and because we mistakenly thoughtthat the north-south magnetic profile of the Challenger
away from Site 215 would enable us to unambiguously
determine the magnetic age of that site. Consequently, we
decided to drill the site originally selected on the
Ninetyeast Ridge at 1°N. This site would enable us toobtain both a continuous calcareous and radiolarian213

SITE 216

sequence back to the Eocene and also to check the rather
spectacular tectonic history for the Ninetyeast Ridge that
resulted from the drilling of Site 214.
The mid-Paleocene age for Site 214 clearly showedthat the Ninetyeast Ridge or at least the area around thesite predated the mid-Eocene readjustment of the plates in
the Indian Ocean. Thus, clearly the ridge was not formedby the compression of the old fracture zone when the
spreading direction of India/Antarctica changed from
north-south to northeast-southwest. Clearly the ridge musthave been formed prior to this time and possibly is afeature similar to Amsterdam and St. Paul islands. Theseislands, which lie to the southeast of the southern end of
the Ninetyeast Ridge, are basaltic islands on a majortransform fault cutting the southeast Indian Ridge. The
ridge could have been formed during the Cretaceous andearly Tertiary by basaltic intrusion at the junction of theold southeast Indian Ridge and the active Ninetyeast
Transform Fault. If this were the case and the extrusion
was onto the Indian plate and not the old Australia/
Antarctic plate, the ridge should be older to the north. If
the magma arises from a point source beneath the Indian
plate, Site 216 should be older than Site 214 and have thesame age difference as the crust a similar distance to thewest of the ridge.
Site 216 is on the Ninetyeast Ridge just north of theequator. In this area the ridge has the more typicalasymmetrical shape and a double crest (Figure 1). The R/VRobert Conrad performed the presite survey (Figure 2), andthe shallow crest at 1200 fathoms was the location chosen
for drilling. The sediment over the crest is well stratified
and about 0.5 sec thick. Two prominent reflectors wereobserved at 0.3 and 0.4 sec on the incoming and outgoing
Challenger profiles. A Cenomanian (Cretaceous) fossil wasrecovered in a dredge from the east scarp during the R/VRobert Conrad site survey.
The objectives were to obtain a continuous Cenozoic
biostratigraphic section, specifically pre-upper Miocene
Radiolaria and to determine the mode of formation andtectonic history of the Ninetyeast Ridge.

-fFigure 1. Bathymetry in vicinity of Site 216.

OPERATIONS

Site 216, on the crest of Ninetyeast Ridge, wasapproached from the west along the seismic reflection
profile of R/V Robert Conrad. The site was selected in awater depth of 2237 meters, after which Glomar Challenger
continued across the ridge for an additional 10 nautical
miles before returning to the selected area. A light sparbuoy was dropped, speed reduced to 5 knots, and theseismic gear secured, after which Challenger returned to thebuoy and the acoustic beacon was dropped.
Drilling was carried out using a Smith 94 CJS 4-conechizzel-point bit. The upper 160-meter section of the hole
was spot cored with cores separated by 19 meters of drilling(2 joints). The remainder of the hole from 160 meters to
the total depth of 477.5 meters was continuously cored. No
drilling difficulties were encountered throughout the 457
meters of drilled sediments. The basalt was cored for 20.5
meters. An aggregate of 353 meters of the section wascored in 38 cores, representing 48.3% recovery (Table 1).

214

Figure 2. Presite survey and form lines at Site 216.

At the conclusion of Hole 216 the drill pipe was pulled
to above mud line and Hole 216A was drilled a shortdistance away. The bit was washed down to 101.5 meters
below sediment surface and six additional cores ofcalcareous ooze taken continuously from 101.5 to 158.5
meters. A total of 57 meters was cored at this offset site
and 53.7 meters recovered, representing 94% recovery(Table 2).
Four heat flow runs were made in Hole 216 (Table 1)
and details are given in Chapter 13.

SITE 216
Unit 2-Volcanic Clay and Micarb Chalk (Cores 25-36)

LITHOLOGIC SUMMARY
Two holes were drilled at Site 216: the main hole,continuously cored from 158.5 meters to the total depth of
477.5 meters, and a complementary hole, 216A, continuously cored from 101.5 meters to the total depth of 158.5
meters. Taken together, the two holes penetrate a sectionthat was continuously cored except for 70 meters near thesurface (Figure 3).
Pleistocene to late Maastrichtian nannofossil ooze andchalk, 348 meters thick, overlies older late Maastrichtian
volcanic clay, micarb, and ash, 110 meters thick, which inturn overlies basalt. Three lithologic units are recognized, as
shown in Figure 3 and below.
Depth Below
Unit Sea Floor (m)la0 to 187lb

187 to 332

lc

332 to 348

2a

348 to 396

2b

396 to 457

3457 to 477.5

Lithology

Age

Cores

Nanno ooze to chalkwith variable foram
content
Nanno chalkPleistocene
to late Oligocene
Late Oligocene to
Paleocene(Danian)Late Maastrichtian

1-7

Glauconite-bearing
clay-rich micarb
chalk
Glauconitic volcanic
clay micarb chalkIntermixed volcanic
clay and micarb
chalk with discrete
beds of ash
Basalt, amygdalar,
vesicular, scoriaceous,and minor vitrictuff

Late Maastrichtian
Late Maastrichtian

8-23

Unit 2 is a complex sequence of greenish grayintermixed volcanic clay and micarb chalk. These sediments
are burrowed and contain bivalves. The volcanic clay occurs
both in the matrix and as sand- and pebble-sized aggregates.
Much of this material is chloritized. The remainder of the
SITE 216,216A
1°27.7'N 90°12.5'E
2247 m«

PLEIST.

i- .-1

PLIO.
Nanno Ooze
and
Chalk

la

with
Forams

23-24

4a
5a 4

25-29

6al_
—5

30-36

L. 6
7
"8

-187

9

-200

u io

36-38

11
13
M.
14
-15
U.lβ=t-17M.
18 = T

Unit 1—Nannofossil Ooze/Chalk (Cores 1-24)
Almost all of Unit 1 is made up of calcareous
nannofossils with variable amounts of foraminifera. The
bulk of this nannofossil material in the lower part of theunit is in large part disaggregated or calcified, and definite
distinguishable nannofossils are rare. There is also some
irregular shaped, coarse, silt-sized material definitely not of
nannofossil origin. Subunit la is white in color and partscontain as much as 50% foraminifera, but most of it
contains about 5%. Subunit lb is almost pure whitenannofossil chalk, in which impurities do not exceed 2%,
except a few thin layers of chert in its lower part. Subunit
lc is light gray and is made up predominantly of silt-sizedcarbonate particles, described here as micarbs, with someforaminifera, nannofossils, clay, and glauconite. The latter
two constituents and the burrowed structure denote atransition to Unit 2. All other constituents in Unit 1 aresiliceous microfossils—radiolarians, diatoms, and sponge
spicules. At a depth of 170 meters, Unit 1 changes fromooze above to chalk below. The actual nomenclaturechange to micarb chalk is arbitrary as there is a progressive
increase of nonidentifiable silt-sized carbonate through Unit
1. However, in Unit lc practically no recognizable
nannofossils remain.

-100

Nanno Chalk

ui 19

ö 20
S 21

(Chert)

-300

2 22
23
lc

24
25

2a

I| 26
27
5 28
gE 29
to

-332
Glauconitic
Foram Clay
Nanno Chalk -348
Glauconitic
Volcanic
Clay Micarb
Chalk

LU

i 30
UJ

2b

31

-> 32
33
34
35

Volcanic
Clay

-396
-400

Micarb
Chalk
and
Ash

-457

BasaltT.D. 477.5 m; 38 cores;
171 m rec.,216A T.D. 158.5 m;
6 cores; 54 m rec.

Figure 3. Lithologic units at Site 216.

215

SITE 216

matrix is micarb chalk and contains as much as 5% each offoraminifera and recognizable nannofossils. Subunit la is agreenish gray glauconitic volcanic clay micarb chalk. Other
constituents, in trace amounts only, are dolorhombs andapatite. Subunit lb is distinguished from la by its higher
content of volcanic clay and basaltic glass, some of thelatter occurring as discrete ash beds, and reduction ofglauconite to trace amounts only. Fossils include bivalve
fragments, foraminifera, and trace amounts of radiolarians
and diatoms. Apatite locally makes up a few percent of therock. As in Subunit la, clay clasts several millimeters acrossare common. A few meters above the contact with basalt isa narrow vein of calcite.
Unit 3-Basalt (Cores 36-38)

The volcanics are divided into: (1) tuff with basaltic
debris, (2) vesicular and amygdalar basalt, (3) fine-grained
basalt with less than 3% vesicles and amygdules, and (4)pale red scoriaceous basalt.
1) The tuff located approximately at 458 meters isinterbedded between thin layers of vesicular and amygdalar
basalt. This lithic tuff consists of an upper portion (about
40 cm) made up mainly of chloritic material, a few basaltic
fragments, and carbonate material; and a lower portion (60cm thick) containing volcanic debris and chloritic material.
The 'chloritic material is made up mainly of chlorite,
vermiculite-chlorite, and it is associated with green mica.
Also the chloritic materials fill areas having the shape of
volcanic shards.
2) The amygdalar and vesicular basalt located mostly inthe lower part of the recovered basalt consists of large
vesicles and amygdules (Core 37, Section 3 and Core 38,
Sections 3 and 4) varying in size from 1 mm to about 15
mm in diameter. The size increases with depth. There is also
an amygdalar zone less than 1 meter thick at the top of thebasalt section. The amygdules of this latter zone are filledwith calcite. The general textural feature of these zones isintersertal medium to fine grained. Microphenocrysts ofpartially chloritized and zoned Plagioclase are set in amatrix containing Plagioclase laths, granules of clinopyroxene, dark mesostasis, calcite, and chlorite.
3) The fine-grained basalt (Core 37, Sections 1, 2, 3,
and 4; Core 38, Sections 1 and 2) consists of more
crystalline and less vesiculated rocks than the rest of theunit. The general texture is pilotaxitic and trachytic. The
major mineral constituents are Plagioclase, clinopyroxene,
iron ore, and chlorite. Some of the opaques (iron ore) showa reaction rim of hematite. The chlorite occurs as analteration product of matrix material and also as inclusions
in Plagioclase microphenocrysts. Thin veins containing
native copper were seen at 110-115 cm (Core 38, Section
1).
The upper and lower portion of the fine-grained basalt is
limited by the occurrence of highly oxidized scoriaceousbasalt.
4) The scoriaceous basalt (Core 36, Section 4; Core 37,
Section 1; and Core 38, Section 3) is highly vesicular andcontains an abundant dark mesostasis enriched in opaques(iron ore), granules of hematite, and glass. Tiny Plagioclase
laths show a subparallel arrangement.

216

CHEMICAL PROPERTIES

Sixteen samples were taken from the 38 cores recoveredat this site. All samples were squeezed for pore water andindividual subprogram quantity requirements were met inall but one instance. Only 2 ml was recovered from
216-28-3, which was preserved for major elements analysis.
Contiguous pairs of minicores were taken from six
carbonate cores and in situ pH measurements were madewith the punch-in electrodes on one sample from each pair.
A special pair of samples was taken from one of the six
cores recovered from Hole 216A and used solely for pH
studies.
Temperature coefficients and pH values obtained fromboth punch-in (sediment) and flow-through (pore water)
measurements are given below. As before, the punch-in data
have been adjusted to the temperature recorded for theflow-through measurements as shown below.

Slope(mv/°C)pH

pH

Sample(punch-in)(flow-through)216-1-6
216-2-5
216-4-5
216-5-5
216-6-4
216-21-2

0.89
0.84
0.92
0.96
0.87
0.85

7.31
6.98
6.77
6.73
6.78
7.21

Temperature
25.2
25.0
26.2
27.5
26.5
25.4

7.69
6.84
7.10
6.84
6.92
7.10

The temperature coefficients show the smallest range forany site so far investigated (0.12 mv/°C). The punch-in pH
values continue to show a smoother trend with depth thanthe data obtained with the flow-through electrode.
Since it is necessary to hold minicores for varying
periods of time up to 24 hours before slope determinations
can be made, the effect of storage was investigated at thissite. A contiguous pair of minicores was taken from
216A-4-5 for this purpose. One sample was placed in the
refrigerator. The other sample was used immediately for aslope determination and the millivolt change was monitored
while warming from the recovery to the laboratory
temperature. At the termination of the experiment thissample was resealed and also placed in the refrigerator.
Slope checks were made on both minicores after 24 hours
storage at 4° C. The results are tabulated below.

Sample216A^-5 (1)216A4-5 (1)(opposite end)
216A-4-5 (2)Slope (mv/°C)

pH (20° C)

0.85
0.89

6.91
6.92

0.96

6.92

While the slopes appear to change with storage, thisdifference can, perhaps, be visualized better in terms of pH
units/°C; this value for the first two measurements is 0.015
and for the third, 0.016. In this instance we conclude thatthe effects of storage are negligible.

SITE 216

TABLE 1
Coring Summary, Hole 216

Core

Date
(Feb)

1

19

2

19

3

19

4

19

5

19

6

19

7

19

8

19

9

19

10

19

11

19

12

19

13

19

14

19

15

19

16

19

17

19

18

20

19

20

20

20

21

20

22

20

23

20

24

20

25

20

26

20

27

20

28

20

29

20

30

20

31

20

32

20

33

20

34

20

35

20

36

20

37

20

38

21

Total

Time

Depth fromDrill Floor(m)

Depth Below
Sea Floor
(m)

0605
0750
0915
1035
1215
1310
1410
1530
1600
1705
1820
1920
1950
2105
2145
2235
2325
0035
0128
0225
0336
0450
0610
0720
0830
1000
1130
1230
1325
1412
1455
1550
1655
1820
1920
2040
2359
0330

2247.0-2256.5
2291.5-2301.0
2329.5-2339.0
2367.5-2377.0
2405.5-2414.0
2415.0-2424.5
2424.5-2434.0
2434.0-2442.5
2443.5-2453.0
2453.0-2462.5
2462.5-2471.0
2472.0-2481.5
2481.5-2491.0
2491.0-2499.5
2500.5-2510.0
2510.0-2519.5
2519.5-2529.0
2529.0-2538.5
2538.5-2548.0
2548.0-2557.5
2557.5-2567.0
2567.0-2576.5
2576.5-2586.0
2586.0-2595.5
2595.5-2605.0
2605.0-2614.5
2614.5-2624.0
2624.0-2633.5
2633.5-2643.0
2643.0-2652.5
2652.5-2662.0
2662.0-2671.5
2671.5-2681.0
2681.0-2690.5
2690.5-2700.0
2700.0-2709.5
2709.5-2715.5
2715.5-2724.5

0-9.5
44.5-54.0
82.5-92.0
120.5-130.0
158.5-167.0
168.0-177.5
177.5-187.0
187.0-195.5
196.5-206.0
206.0-215.5
215.5-224.0
225.0-234.5
234.5-244.0
244.0-252.5
253.5-263.0
263.0-272.5
272.5-282.0
282.0-291.5
291.5-301.0
301.0-310.5
310.5-320.0
320.0-329.5
329.5-339.0
339.0-348.5
348.5-358.0
358.0-367.5
367.5-377.0
377.0-386.5
386.5-396.0
396.0-405.5
405.5-415.0
415.0-424.5
424.5-434.0
434.0-443.5
443.5-453.0
453.0-462.5
462.5-468.5
468.5-477.5

Cored
(m)

Recovered(m)

Recovery
(%)

9.5

9.5

100

9.5

9.5

100

9.5

2.1

22

9.5

9.5

100

8.5

8.5

100a

9.5

9.5

100

9.5

2.6

30

8.5

2.6

32 a

9.5

4.5

48

9.5

2.8

29

8.5

0.9

10 a

9.5

2.1

23

9.5

5.6

6

8.5

3.5

41a

9.5

3.6

38

9.5

3.8

40

9.5

2.8

29

9.5

0.4

4

9.5

0.3

3

9.5

5.4

57

9.5

2.2

24

9.5

3.6

38

9.5

3.6

38
66

9.5

6.3

9.5

6.5

67

9.5

4.0

42

9.5

3.0

31

9.5

3.6

38

9.5

2.5

26

9.5

7.1

75

9.5

6.6

70
86

9.5

8.2

9.5

3.0

32

9.5

6.1

64

9.5

3.4

36

9.5

5.5

58

6.0

5.2

87

9.0

6.0

67

353.0

175.9

48.3

Note: Echo sounding depth (to drill floor) = 2262 meters; drill pipe length to bottom = 2247
meters.
aHeat flow runs.

217

SITE 216
TABLE 2
Coring Summary, Hole 216A

Core

Date
(Feb)

1

21

2

21

3

21

4

21

5

21

6

21

Time

Depth fromDrill Floor(m)

Depth Below
Sea Floor
(m)

0945
1045
1140
1220
1320
1415

2348.5-2358.0
2358.0-2367.5
2367.5-2377.0
2377.0-2386.5
2386.5-2396.0
2396.0-2405.5

101.5-111.0
111.0-120.5
120.5-130.0
130.0-139.5
139.5-149.0
149.0-158.5

Cored
(m)

Recovered(m)

Recovery
(%)

9.5

8.8

92
98

Totals

9.5

9.3

9.5

8.7

92

9.5

9.0

95

9.5

9.0

95

9.5

8.9

93

57.0

53.7

94

Note: Echo sounding depth (to drill floor) = 2262 meters; drill pipe length to bottom = 2247
meters

BIOSTRATIGRAPHIC SUMMARY
GeneralThe carbonate section extends from Pleistocene to late
Maastrichtian. Preservation of calcareous fossils is consistently poorer at Site 216 than at Site 214.
A thick basal section consists of glauconites, mudstones,
carbonates, volcanics, and the sediments were probably all
deposited in relatively shallow water. There are enoughnannofossils throughout the interval to suggest rapid
accumulation entirely within the Nephrolithus frequens
Zone (Late Maastrichtian).
The Cretaceous/Tertiary boundary can be pinned down
to a horizon at Sample 23-2, 105 cm, which marks a change
in sediment structure from bioturbated, variegated, andwith well-defined burrows (upper Maastrichtian) tohomogeneous and relatively featureless, though well
worked over biologically (Danian). A break in sedimentation, representing perhaps 2 m.y. corresponds to theCretaceous-Tertiary boundary.
Foraminifera

Cores 1 to 4 extend from the Pleistocene to the middle
Miocene. Cores 5 to 8 cover the zone interval N.5 to N.3.
Globigerinoides is associated with the Globorotalia kuglerigroup in 6, CC but not in Core 7, Section 1, and the
Oligocene/Miocene boundary is placed tentatively between
these samples. However, the Globigerinoides record in notgood for preservational reasons, and there are indications
that N.5 is mixed with N.4. Cores 9 to 16 are progressively
less satisfactory, again because of the absence of numerous
species. The middle upper Eocene boundary is placed above
the disappearance of Truncorotaloides and Acarinina (i.e.,
above 17-2); this is a good approximation in low latitudes.
Preservation is still poor, but better, and specimen numbers
increase downhole dramatically at this level. Successive
cores record lower middle Eocene, no lower Eocene, andplenty of Paleocene sediment. The latter ends within Core
23, Section 1; where there is a Zone P.lc (upper Danian)assemblage, identified by the presence of Planorotalites
compressa. The lowest sample taken with this assemblage is
5 cm above a well-marked contact at 105 cm, and 5 cm

218

below this there is an upper Maastrichtian assemblage.
Thus, the Cretaceous/Tertiary boundary is placed at thiscontact, and there is a hiatus here valued at some 2 m.y. In
terms of good correlations, the record ends with Core 24(upper Maastrichtian). Globotruncana mayaroensis isunusually common in 23, CC.
Both benthonic and planktonic species occur consistently in Cores 25 through 35. The latter are represented by
Heterohelix, Guembelitria, and ? Hedbergella—only a small,tough fraction of the oceanic fauna of the time and rare inoccurrence. Benthonics are also sparse but rather diverse interms of total taxonomic accumulation; agglutinated forms
are no more common than in open-shelf assemblages;
Lenticulina, nodosariids, buliminids, and cibicidids are themost persistent, although gavelinellids are common at the
top; on the sparse recoveries available no significant change
has been detected through the three main lithologies. The
data are consistent with the idea of a shallow, somewhat
restricted environment into which the "more inshore"
planktonics were washed and within which benthonics
could exist; salinity was not significantly below normal.
That is, age is the main difference between basal Site 216
and basal Site 214.
Nannofossils

Calcareous nannofossils were recovered at Site 216
throughout the sedimentary interval cored, and range in age
from Quaternary to late Maastrichtian. Because of
discontinuous coring an incomplete Neogene record was
obtained. Gaps in the record below the Miocene may
correspond to hiatuses as this interval was coredcontinuously. Core 1 is entirely Pleistocene in age but
represents less than half a million years of late Pleistocene
history. Core 2 represents a mid-Pliocene interval and Cores
3 through 7 recovered Miocene sediments. The OligoceneMiocene boundary probably is within Core 8, though thenannofossils do not yield a precise boundary. The rather
thick Oligocene section extends through Core 15, Section 3
with a good part of the early Oligocene interval missing or
represented in a much attenuated portion of Core 15,
Section 2. Late and middle Eocene sediments were

SITE 216

recovered from the core catcher of Core 15 down throughCore 18, Section 2, with possible early Eocene sediments inthe core catcher of Core 18. An incomplete Paleocene
section was recovered in Cores 19 through 23, Section 2,
with the Cretaceous-Tertiary boundary contained within
Section 2 between 105 and 110 cm. The remaining
calcareous sediments are all assignable to the late
Maastrichtmn Nephrolithus frequens Zone.
The preservation of nannofossils throughout the interval
is poor except in the Pliocene and Pleistocene. Species
diversity is low and many specimens are heavily calcified. It
is noteworthy, perhaps, that the late Maastrichtian ismarked by the presumed high latitude index species
Nephrolithus frequens and by the exclusion of the low
latitude indicator for this interval, Tetralithus mums.
Hole 216A was drilled in order to recover a continuous
section of the early Neogene interval which contains
well-preserved Radiolaria. The six cores taken for thispurpose range in age from the late Miocene {Discoasterneohamatus Zone) at the base of Core 216A-1 to the early
Miocene at the base of Core 216A-6.
Radiolaria

Radiolaria in cores obtained at Holes 216 and 216A
range in age from Quaternary to Upper Cretaceous(Maastrichtian). The Quaternary and Pliocene section(Cores 216-1, 216-2, and 216-3) contains moderately topoorly preserved Radiolaria. The upper Miocene to upper
Eocene section (Cores 216A-1 through 216-17) contains
generally well-preserved radiolarian assemblages. There is atransition zone near the upper-middle Eocene boundary(Cores 216-18 and 216-19) within which Radiolaria aresparse and poorly to moderately preserved. Within theinterval between the upper Eocene sediment and thebasaltic "basement" Radiolaria are absent, except for a few
specimens of Upper Cretaceous (Maastrichtian) Radiolaria
which are present in Cores 30 and 31.
Only three cores were obtained from the Quaternary and
Pliocene sediment. Core 216-1 is Quaternary; Core 216-2 isin the lower Pliocene Spongaster pentas Zone; Core 216-3 isin the upper Miocene Stichocorys peregrina Zone.
The base of the Stichocorys peregrina Zone is between
Samples 216-3, CC and 216A-1-1, 70-72 cm. The base of
the Ommatartus penultimus Zone is between Samples
216A-1, CC and 216A-2-1, 66-68 cm. The base of the
Ommatartus antepenultimus Zone is between Samples
216A-2, CC and 216A-3-1, 43-45 cm. The base of the
Cannartus petterssoni Zone is between Samples 216A-3, CC
and 216A-4-2, 73-75 cm. The base of the Dorcadospyris
alata Zone is between Samples 216A-5-5, 70-72 cm and
216A-5, CC. The base of the Calocycletta costata Zone is
between Samples 216A-6, CC and 216-5-1, 110-112 cm.
The base of the Calocycletta virginis Zone is between
Samples 216-8-2, 30-32 cm and 216-8, CC. The base of the
Lychnocanoma elongata Zone is between Samples 216-8,
CC and 216-9-1, 30-32 cm. The base of the Dorcadospyris
ateuchus Zone is between Samples 216-12-1, 110-115 cm
and 216-12-2, top. The base of the Theocyrtis tuberosa
Zone is between Samples 216-14, CC and 216-15, CC. Thebase of the Thyrsocyrtis bromia Zone is between the baseof Core 16 and the top of Core 17. No samples wereobtained from the Podocyrtis goetheana and Podocyrtis
chalara zones; consequently, there appears to be a hiatus
between the base of Core 16 and the top of Core 17. Cores
17 through 19 contain moderately to poorly preserved
Radiolaria which are within the Podocyrtis mitra Zone.
Below Core 19 Radiolaria are absent, except for several
upper Maastrichtian species in the core catcher of Cores 30
and 31.
CORRELATION OF REFLECTION PROFILEAND STRATIGRAPHIC COLUMN

Site 216 is situated on the crest of Ninetyeast Ridge.
The seismic reflection profile of the general area shows asediment cover varying between 0.4 and 0.7 sec in thickness(Figure 4). This sediment appears to be draped over thebasement of the ridge.
Generally speaking, acoustic basement in the vicinity ofSite 216 is continuous and well defined and can confidently
be traced to the actual site area where it occurs at a depthof 0.44 sec. Within the sediment overlying basement, twozones of acoustic layering occur at 0.13 and 0.27 sec. Thesezones are separated from each other as well as fromsediment surface and basement by acoustically relativelytransparent layers.
The only correlation that can be made with confidence
between the airgun record and stratigraphic column is thatof the basalt surface. This occurs at a sediment depth of
457 meters, representing 0.44 sec on the seismic profile. If
this correlation is correct, the interval velocity of the entire
sediment column is 2.1 km/sec.
The two reflectors within the sediment layer do notcorrelate well with any obvious lithological parameters. It is
possible that the lower reflector may be due to chert
stringers which begin at a sediment depth of about 280
meters.
Depths of reflectors and interval velocities are as follows:
Reflector
01242-Way Time Depth
(sec)
(m)
0

0.13
0,28
0.44

0
130
282
457

Interval Velocity(km/sec)
2.0
2.2
2.0

2.1

SUMMARY AND CONCLUSIONS

Site 216 was selected on the crest of Ninetyeast Ridge
approximately 1° north of the equator in a water depth of
2237 meters. The seismic reflection profile of the area
indicates a relatively thick sedimentary section overlying
seismic basement. In the actual site area the section is about
0.5 sec thick and is composed of acoustically bedded
sediments draped over the basement topography. No
obvious ponding of the layers is evident, althoughthickening of sediments occurs in some cases on the flanksof the Ridge, possibly due to slumping.
The stratigraphic column at Site 216 comprises threeunits, the lowermost of which is a tholeiitic basaltic rockwith a composition similar to suites from St. Paul and New
Amsterdam islands and significantly different frommidocean ridge basalts. Lack of pillow structures and the219

SITE 216

SITE 216

SECS

Nanno ooze and chalk
Foraminiferal in part

Glauconitic andburrowed at baseLower Reflector
0.27
Acoustic basement
0.44

Micarb chalk andvolcanoclastics

BasaltFigure 4. Correlation of reflection profile and stratigraphic column at Site 216.

amygdalar and vesicular nature of the rock suggest aerial ornear-surface lava extrusion.
The oldest sedimentary unit, immediately overlying thebasalt, consists of late Maastrichtian ash beds, chalks, andvolcanogenic clays. Microfossil evidence, the presence of amolluscan fauna, and the occurrence of glauconite attest toa shallow water environment. By Paleocene time,
paleontological evidence as well as the upward disappearance of glauconite suggest deepening of the area. The
uppermost lithologic unit, of late Maastrichtian toPleistocene or Recent age, is mainly composed offoraminifera-bearing nannofossil ooze and chalk. Sediments of this unit typify pelagic calcareous sedimentation
above the CaCθ3 compensation depth and document
further subsidence of the Ninetyeast Ridge to oceanic
depths. This subsidence occurs earlier at this site than at
Site 214.

220

The oldest sediments at Site 216 are 8 to lOm.y. older
than those at Site 214. Site 216 is 1400 km north of Site
214. Thus the "effective" spreading rate on this featureduring the Late Cretaceous and early Tertiary is between 18
and 14 cm/yr. This is significantly greater than the
spreading rate for the Indian plate during this time span
(between 6 and 12 cm/yr). This is strong evidence that theorigin of the Ninetyeast Ridge cannot be totally accounted
for by a point source magma chamber beneath the Indian
plate.

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

Site 216

Hole

Core 1Site 216

Cored I n t e r v a l : 0-9.5 m

HoleCore 2

Cored Interval: 44.5-54.0 m

FOSSILCHARACTERFOSSILCHARACTER

LITHOLOGIC DESCRIPTION

LITH0L0GIC DESCRIPTIONFORAM NANNO OOZE
bluish white (5B7/1), massive,vague mottles
Forams30%
Nannos
60%
Clay
10%

NANNO FORAM OOZEy e l l o w i s h gray (5Y7/2)
Volcanic glass(rhyolitic)

mottle (dark gray)

ForamsNannosDiatoms
Rads
Spicules,Claysilicoflag.

2%
55%
32%
Tr.
1%
Tr.
10%

5B9/1

FORAM NANNO OOZE
pale blue (5PB7/2)
Glass
ForamsNannos
Clay

1%
35%
54%
10%

very pale orange (10YR8/2)
FORAM NANNO OOZE

]L°'^! mterbeds— o l i v e graygrayish yellow(5Y8/4)o l i v e gray (5Y4/1), streaks ofl i g h t gray
Forams25%
Nannos65%
Clay
10%
FORAM NANNO OOZE
10YR8/2, m o t t l e s o f gray
Glass
ForamsNannos
Clay

1%
29%
60%
10%

Not opened.

5Y4/1
5Y8/4
10YR8/2— White (N9)7090very l i g h t gray(N8)
w h i t e (N9)N9Core
Catcher

Explanatory notes in Chapter 1toto

GEO CHEM SAMPLE
FORAM AND NANNO RICH RHYOLITIC ASH
dusky yellow green (5GY5/2)
Feldspar1%
Mica
1%
Heavy minerals
Tr.
Glass
70%
Forams14%
Nannos14%

FORAM NANNO OOZE
w h i t e (N9)ForamsNannosRHYOLITIC GLASS ASH
5Y4/1
FeldsparGlass
ForamsNannos20 —If

FELDSPAR BEARING RHYOLITICGLASS ASH
5Y4/1
FeidsparHornblende
Volcanic glass
ForamsNannosFORAM NANNO OOZE
GlassForamsNannosDiatoms
Rads

3%
95%
Tr.

27%
70%
1%

Core
Catcher
Explanatory notes in Chapter 1

FORAM NANNO OOZE
medium light gray (N6)Glass
ForamsNannos
Clay

1%
30%
59%
10%

FORAM NANNO OOZEForamsNannos
Clay

30%
60%
10%

S i t e 216

Hole

S i t e 216

Cored I n t e r v a l : 8 2 . 5 - 9 2 . 0 m

Hole

Cored I n t e r v a l :120.5-130.0 m

FOSSILCHARACTERFOSSILCHARACTER

LITHOLOGIC DESCRIPTION

LITHOLOGIC DESCRIPTIONb l u i s h white (5B9/1)
w i t h harder layers general f o r whole coreinterbeds as
indicatedl i g h t bluish gray (5B7/1)

NANNO OOZEForains
NannosRads
Clay
GLASS BEARING NANNO OOZE
blue gray
FeldsparMica
Glass (Rhyolitic)
PyriteForamsNannos
Rads
Clay

Core
Catcher

NANNO OOZE
l i g h t b l u i s h gray (5B7/1), withdarker gray mottles
Forams10%
Nannos85%
Clay
5%

NANNO OOZE
GlassMicronodules
ForamsNannos
Clay

Tr.
5%

Tr.
Tr.
Tr.
Tr.
5%

Tr.
Tr.
Not opened.

5%

Explanatory notes i n Chapter 1

GEO CHEM SAMPLENANNO OOZEForamsNannosR h y o l i t i c glass
Clay

X-ray a t 121.10 m Calc 100

Core
Catcher
Explanatory notes i n Chapter 1

Site 216

Hole

Core 5

S i t e 216

Cored I n t e r v a l : 158.5-167.0 m

LITHOLOGIC DESCRIPTION

HoleCore 6

Cored I n t e r v a l : 168.0-177.5 m

LITHOLOGIC DESCRIPTION

Site 216

Hole

Core 7

Cored Interval: 177.5-187.0 m

Site 216

Hole

Core 9

Cored Interval: 196.5-206.0 m

FOSSILCHARACTER
LITHOLOGIC DESCRIPTIONNANNO CHALK
white (N9)ForamsNannosRads
SpiculesSilicoflag.
Clay

LITHOLOGIC DESCRIPTIONNANNO CHALK
white (N9)FeldsparForamsNannos
Clay.

Tr.
Tr.
Tr.

Tr.
Tr.
51

Not opened.

Not opened.

Core
CatcherSite 216

Hole

Core 8S i t e 216

Cored Interval: 187.0-195.5

HoleCore 10

Cored I n t e r v a l :206.0-215.5 m

FOSSILCHARACTERFOSSILCHARACTER

LITHOLOGIC DESCRIPTION

LITHOLOGIC DESCRIPTIONHeat f l o w : not opened.
NANNO CHALK
white (N9)ForamsNannosRads
Spicules
Clay

.1 I
100

NANNO CHALK
white (N9)ForamsNannosRads
SpiculesClay

Not opened.

Tr.
Tr.

Core
CatcherCore
Catcher

Explanatory notes in Chapter 1

Explanatory notes in Chapter 1

Tr.
95,.
Tr.
Tr.

Site 216

Hole
FOSSILCHARACTER

Core 11Site 216

Cored Interval; 215.5-224.0 m

Hole
FOSSILCHARACTER

Core 14

Cored I n t e r v a l : 244.0-252.5 m

LITHOLOGIC DESCRIPTION

LITHOLOGIC DESCRIPTIONNANNO CHALK
white (N9)NANNO CHALK
white (N9)ForamsNannosRads
SpiculesClay

NANNO CHALK/OOZE
white (N9)Core
Catcher

Tr.
Tr.
Tr.
S%

Not opened.
Site 216

Hole
FOSSILCHARACTER

Core 12

Cored Interval; 225.0-234.5 m

LITHOLOGIC DESCRIPTIONNANNO CHALK
white (N9)Authigenic carbonates
ForamsNannos
Clay

1%
Tr.
94%
5%

Site 216

Hole

Core 15

Cored Interval: 253.5-263.0 m

Not opened.
LITHOLOGIC DESCRIPTION

Site 216

Hole
FOSSILCHARACTER

Core 13NANNO CHALK
white (N9)ForamsNannosRads
SpiculesClay

Cored I n t e r v a l ; 234.5-244.0 m

LITHOLOGIC DESCRIPTION
Not opened.

ü
«

3
2

.C r— ONANNO CHALK
white (N9)ForamsNannosRads
Spicules
Clay

Tr.
Tr.

Explanatory notes in Chapter 1

to
NJ

Explanatory notes in Chapter 1

Tr.
9E;
Tr.
Tr.
5?

Site 216

Hole
FOSSILCHARACTER

Core 16Site 216

Cored Interval; 263.0-272.5 m

HoleCore 18

Cored Interval; 282.0-291.5 m

LITHOLOGIC DESCRIPTION

LITHOLOGIC DESCRIPTIONNANNO CHALK
white (N9)CHERTyellowish gray (5Y8/1) anddark yellowish brown (10YR4/2)
bands 1 cm thick.
NANNO CHALK
white (N9)scattered grainsof pumice

Not opened.

CHALK AND 2 pieces CHERT
moderate reddish brown,
gray and white.

Core
Catcher
HoleCore 19

NANNO CHALK
white (N9)Authigenic carbonates
ForamsNannosClayJCoreCatcher

1%
%
88%
10*

PRES.

AGE

LITHOLOGIC DESCRIPTION

AßUND.

FOSSILCHARACTER

LITHOLOGY

LITHOLOGIC DESCRIPTION

0.5VOID

1

F

C

P

N
F
R

R
C

P
P

l.<H
139
Core
Catcher

Explanatory notes in Chapter 1
Explanatory notes in Chapter 1

Cored I n t e r v a l : 291.5-301.0 m

DEFORMATION

Site 216

LITHO.SAMPLE

272.5-282.0 m

METERS

Cored Interval:

SECTION

Core 17

ZONE
Morozovella velascoensis Zone (P5) (F)M. velascoensis - M. subbotinae Zone (P6a) (F)
FOSSILHole
FOSSILCHARACTER

PALEOCENE

Site 216iii

NANNO CHALK
white (N9)lenses of yellowish gray
(5Y8/1)Goethite
Authigenic carbonates
NannosCl ay

X-ray at 292.60 m Calc 87, Quar < l , Paly 12

Tr.
2%
93%
5%

Site 216

Hole
FOSSILCHARACTER

Core 20

Cored Interval: 301.0-310.5 m

Site 216

Hole
FOSSILCHARACTER

Core 22

LITHOLOGIC DESCRIPTION

Cored Interval: 320.0-329.5 m

LITHOLOGIC DESCRIPTION

MnO 2 HICRONODULES
white (N9): also l i g h t o l i v egray 5Y6/1 and grayish orange
pink (5YR7/2).

NANNO CHALK
white
Auth. carb.
NannosClay

MnO2 dots

NANNO CHALK
Nannos
Clay

ε

Core
Catcher

S i t e 216

Hole

Core
CatcherCore 21

Explanatory notes in Chapter 1

Cored I n t e r v a l : 310.5-320.0 m

FOSSILCHARACTER
LITHOLOGIC DESCRIPTION

g r a y i s h orange pink
(10R8/2) c h e r t y chalk

G 0 CHEM "SAMP E

1chert, dark reddish
brown (10R3/4)

NANNO OOZE
pinkish white
NannosForamsAuthigenic carbonates
Claywhite chalk

pin t white oozeche " t , as above
whi te chalk, MnO2
mi ro nodules, l i g h t
gr y laminaeεCoreCatcherwhite chalk
X-ray at 311.20 m Calc 99, Quar 1

Explanatory notes in Chapter 1

H
W
to
-J

to

NJ

to

Site 216

00

Hole
FOSSILCHARACTER

Cored Interval: 329.5-339.0 m

Site 216

Hole
FOSSILCHARACTER

Cored Interval; 339.0-348.5 m

LITHOLOGIC DESCRIPTION

LITHOLOGIC DESCRIPTION

low P3(F)

CHERTgrayish red 5R4/2

FORAM RICH MICARB CHALK
very light gray N8 with mottlesof light gray N7
Clay
5%
Glass
Tr.
Forams10%
Micarb and Nannos
85%

CHALK
white N9very l i g h t gray N8 ( s l i g h t l y darker
gray streaks and mottles)
Glass
Tr.
Glauc.
Tr.
Dolo. rhombs
Tr.
Chert
Tr.
Forams2%
Nannos90%
Clay
5%
NANNO CHALK

Glauc.
Tr.
Forams2%
Nannos93%
Clay5%
light gray N8 and light gray N7, withpale green 10G6/2

121

Core
Catcher

MICARB CHALK
FeldsparGlauc.
Auth. carb.
ForamsNannosClay
MICARB CHALK
burrowed N8 and N7

FORAM bearing CLAY RICH MICARB
CHALKburrowed laminae of dark greenish
gray 5G4/1
FeldsparClay
Micarb and Nannos
Forams

S" %
i-

Tr.
10%
87%
3%

>i

I1

Tr.
Tr.

dark greenish
gray 5GY4/1

1%.-:;<.,
5%

ZEOLITE bearing MICARB CHALK
Clay
5%
Glass
Tr.
Glauc.
Tr.
Dolo. rhombs
Tr.
Zeolite
3%
Chert
Tr.
Forams2%
Nannos3%
Micarb87%

FORAM RICH MICARB GLAUCONITE
dusky blue green 5BG3/2 laminatedGlauc.
50%
Forams20%
Micarb and Nannos
30%

grayish blue green
5BG5/2 mottled

clast, burrowed
with matrix

Explanatory notes in Chapter 1

GLAUCONITE bearing FORAM RICH CLAYMICARB CHALK
light bluish gray 5B7/1, mottled
and burrowed with green
Cl ay
Gl auc.
ForamsMicarb and Nannos

X-ray at 345.90 m Calc 95, Quar < l , Clin 5

Explanatory notes in Chapter 1

30%
5%
25%
40%

Site 216

Hole

Core 25

Site 216

Cored Interval: 348.5-358.0 i

HoleCore 26

Cored Interval: 358.0-367.5 m

LITHOLOGIC DESCRIPTION

LITHOLOGIC DESCRIPTIONGLAUCONITE bearing MICARBVOLCANIC CLAYSTONE
white N9 and grayish blue green
5BG5/2 burrowed. Burrows 0.5-1.0
cm across. Rare dusky blue green
5BG3/2 mottles
Clay (volcanic origin?) 68%
Micarb25%
Forams5%
NannosTr.
Glauc.
2%
FeldsparTr.

Mottles/clasts
greenish gray
5GY6/1

GLAUCONITE bearing MICARB VOLCANICCLAYSTONE

black mottle:
foramsoyster(sampled)

dark greenish gray 5G4/1 and greenish
gray 5G6/1 burrowed, with mottles
of greenish black 5G2/1
Clay (volcanic origin?) 65%
Glass (basaltic)
Tr.
Glauc.
2%
Dolo. rhombs
Tr.
Auth. carb.
Tr.
ApatiteTr.
Forams2%
Micarb31X

Calcite veins

GLAUCONITE bearing MICARB ASH
Clay
25%
Glass
40%
Glauc.
2%
Dolo. rhombs
Tr.
Carb.
1%
Forams2%
NannosIS
Micarb29%

foram clay
carbonate bearing
feldspar r i c h micrite

GLAUCONITE RICH CALCAREOUS
VOLCANIC SANDY CLAYSTONE
Feldspar
5%
Glass
20%
Clay grains
25%
Glauc.
15%
Shell fragments
5%
Micarb25%
Forams5%

X-ray at Section 2, 70 cm
CalciteQuartzMontmor.
Analcite
Chabazite

Site 216

X-ray at Section 4 , 90 cm
CalcitePlagioclase
Montmor.
Clinopt•

GLAUCONITE bearing CALCAREOUS
VOLCANIC SANDY CLAYSTONE
dark greenish gray 5G4/1 sandy
muds tone with mottles/clasts
from sand grain to 1 cm size ofgreenish black 5GY2/1 and shellfragments, presumably of bivalvesvariably burrowed.
Clay aggregates and clay
(volcanic?)
60%
Micarb and Nannos
25%
Glauc.
10%
Forams5%

HoleCore 27

27 %

<u
57%
15%
present

Cored Interval: 367.5-377.0 m

48%
6%
45%
1%

Explanatory notes in Chapter 1

nntes in Chanter 1

H
M
to

to

w
o

Hole

Cored Interval: 396.0-405.5 m

Cored Interval: 377.0-386.5 m

LITHOLOGIC DESCRIPTION

LITHOLOGIC DESCRIPTION

dark greenish gray
5G4/1, with lightand dark sand grains,
scattered burrows,
shellspale o l i v e 10Y6/2,
darker mottles andburrows

CLAY MICARB RICH ASH
Glass
Clay
MicarbNannosRads
Sponge s p i c .

GLAUCONITE BEARING GLASS RICH
VOLCANIC CLAY
Clay
Glass
Clay aggregates
Glauc.
ForamsNannosNANNO RICH MICARB VOLCANIC CLAY
Feldspar5%
Glass
Clay aggregates
Micarb20%
NannosTr.
Rads
2%Sponge s p i c .

2058
2058
40%
5%
5%
IM

MICARB VOLCANIC CLAY
Glass
Clay
MicarbForamsNannosSponge s p i c .
MICARB VOLCANIC CLAY
FeldsparClay
MicarbForamsNannosDiatoms
Rads
Sponge s p i c .

Core 29

Cored I n t e r v a l : 386.5-396.0 m

VOLCANIC ASH
black
FeldsparB a s a l t i c glass
LITHOLOGIC DESCRIPTION

greenish black
5GY2/1 w i t hgreenish graymottles 5G6/1
and bivalvesgradationalboundarygrayish black N2

Explanatory notes in Chapter 1
GLAUCONITE bearing CALCAREOUS
VOLCANIC SANDY CLAYSTONE
dark gray N3
Clay (chlorite)
30%
Glass
20%
Glauc.
5%
Carbonate
5%
Micarb30%
Forams5%
Nannos5%
Thin section of C.C.
Altered Vitric Tuff
Mostly devitrified and chloritized
glass, few shards still visible.
Feldspar phenocrysts more common
than clinopyroxene and lava fragments. Few forams present. Some
patches of glass show spherulitic
texture and a few spherules are
lined with zeolite.

Explanatory notes in Chapter 1

X-ray a t Section 1 , 90 cm
CalciteQuartzPlagioclase
Montmor.
PyriteAugite

50?
5%
Tr.
2%
5%
Yi
M
1%
50%
39%
1%
1%
2:
]';',

3%
97%

1%

Site 216

Hole

Core 31

Cored I n t e r v a l : 405.5-415.0 m

Site 216

Hole

Core 32

Cored I n t e r v a l : 415.0-424.5

LITHOLOGIC DESCRIPTION

LITHOLOGIC DESCRIPTION

pale olive 10Y6/2,
with black and lightgray mottles andburrows

GLASS RICH VOLCANIC CLAY MICARB
pale o l i v e 10Y6/2, with bivalves,
and white and black mottles andburrows, and numerous black sandsized g r a i n s .
Feldspar
Tr.
Clay
303!
Vole, glass
20%
Glauc.
Tr.
Auth. carb.
5%
Micrite44?
ForamsTr.
Sponge spic.
IX

Not opened.

X-ray at Section 1 , 110 cm
Calcite72%
Plagioclase
14%
Pyrite2%
Augite12*

MICARB VOLCANIC CLAY
moderate blue green 5BG4/6 and veryl i g h t gray N8, burrowed
Feldspar
Tr.
Glass
5 SS
Clay
Mi carb
Sponge s p i c .
1%

4 not opened
MICARB VOLCANIC CLAY
FeldsparClay
Glass
Mi carb
ForamsNannosrare shellfragments

GLASS RICH MICARB VOLCANIC CLAY
blue green, as in Section 3
Glass
10%
Clay
44%
Micarb40%
Di atoms
5%
Rads
Tr.
Sponge spic.
1SS

Not opened.

Explanatory notes in Chapter 1

X-ray a t 418.00 m Calc 87, Quar 1 , Plag 3, Mont 4 ,Pyri 1 , Augi 4

Explanatory notes in Chapter 1

toSite 216

Hole

Core 33

Cored Interval: 424.5-434.0 m

Cored Interval; 434.0-443.5 m

to
LITHOLOGIC DESCRIPTIONMICARB RICH VOLCANIC CLAY
grayish o l i v e 10Y4/2
Feldspar
Heavies
Clay
MicarbForamsDiatoms
Vole, glass

Section 2
not opened.

CHLORITIC VOLCANIC CLAY
grayish black N2, hard
FeldsparMicarbClay ( c h l o r i t i z e d )GlassHeavies
X-ray at Section 1 , 100 cm
CalcitePlagioclase
Montmor.

Clinoptilolite
Phillipsite
PyriteAugiteLITHOLOGIC DESCRIPTION

f a i n t burrows
10%
20%

::-:
1*

15%

MICARB RICH VOLCANIC CLAY
greenish gray 5GY6/1, fineshell fragments
FeldsparClay
Glauc.
PyriteAuth. carb.
ApatiteMicarbForams

1%

Tr.

λ%
3%

12

Not opened.

5%
15%

APATITE bearing MICRITE RICHSANDY MUDSTONE
FeldsparClay (volcanic?)
PyriteAuth. carb.
ApatiteMicarbForamsSponge s p i c .

15%
4%
48%
3%
18%
1%
11%

Tr.
72%
Tr.
5%
2%
20%
1%
Tr.

GLASS RICH CLAYEY LIMESTONE
moderate blue green 5BG4/6

dense white specks

Explanatory notes in Chapter 1

as at top

FeldsparClay
Glass
Chlorite
CalciteMicrite

Tr.
30%
10%
U
40%
19%

Vitric Tuff
FeldsparClay
Glass
Chlorite

2%
8%
40%
50%

Thin Section at 79 cm Section 4
Vitric Tuff
Partially altered and strongly
chloritized basaltic glass shards.
The glass is very spherulitic withspherules f i l l e d with analcite (withsome chlorite) andcalcite. Some feldspar laths present.
as above
X-ray at 434.50 m Calc 37, Plag 6, Mont 37, Clin 17,
Pyri 2
X-ray at 439.20 m Calc 49, Quar 1 , Plag 7, Mont 20,
Phil 23, Pyri 1
X-ray at 439.20 m Mica 53, Mont 23, Phil 23

Explanatory notes in Chapter 1

Site 216

Hole

Site 216

Cored Interval: 443.5-453.0 m

HoleCore 36

Cored Interval: 453.0-462.5 m

LITHOLOGIC DESCRIPTION

LITHOLOGIC DESCRIPTIONCALCITE RICH HICARB VOLCANIC CLAY
dark greenish gray 5G4/1 withwhite and black grains
Feldspar5%
C h l o r i t i c clay
44%
CalciteMicarb
30%
Sponge spic.
1%

VOLCANIC CLAY
dark gray N3 shell fragment,l i g h t gray mottles and burrows
Heavies (Fe-oxide)
10%
Clay
75%
Auth. carb.
10*
ForamsTr.
Zeolite {analcite ?)5*

MICARB RICH CALCITIC VOLCANIC CLAY
dusky blue green 5BG3/2
Fe-oxide5%
C h l o r i t i c clay
65%
Calcite20%
Micarb10%

CHLORITIZED CLAYEY MICRITE
Feldspar
Tr.
Clay
30*
Glass
Tr.
Auth. carb.
15*
Micarb55%

SHELLY MICARB VOLCANIC CLAY
dark greenish gray 5G4/1, clasts
up to 3 nm acrossFeldspar
2%
36%
Clay
Glauc.
2%
Calcite10%
Shell fragments
20%
Micarb30*

CLAYEY CALCAREOUS ASH
FeldsparGlass
ClayAuth. carb.
Micarbl i g h t bluish gray
5B7/5 w i t h rusty
bordersb a s a l t , amygdalar,med. dark gray N4pale green 10G6/2
sediment

CLAYEY LIMESTONE
greenish gray 5G6/1 w i t h darkgreen burrows
Feldspar
1%
20%
Clay
Auth. carb. and Shellfragments
79%
MICRITE CLAY LIMESTONE
pale blue green 5BG7/2
Clay

b a s a l t , amygdalar, N4
Mi*^bCarb'
grayish red purple
5RP4/2 and p a l e
VOLCANOGENIC SEDIMENT
green
p a l e green 10G6/2

Explanatory notes in Chapter 1

basalt, scoriaceous,

1%
40*
29*
20*
10*

30*
50%
20%

rl?':i(.ogPyroxene
Dark mesostasis

73*

LITHIC VITRIC TUFF
Thin section at Section 4, 70 cm
Glassy brown altered lava fragments some trace feldspar laths few microcryst lava, many altered glassy
spheruiitic chloritized lavas. Few
lavas show feldspar phenocrysts, andpyroxene microcrystals abundant FeO
in and around lava fragments. Fragments welded with analcite andchlorite needles rimming this or as
inclusions within.
Explanatory notes in Chapter 1

to

to

S i t e 216

HoleCore 37

S i t e 216

Cored I n t e r v a l : 4 6 2 . 5 - 4 6 8 . 5 πt

HoleCore 38

Cored I n t e r v a l :468.5-477.5 m

FOSSILCHARACTERFOSSILCHARACTER

LITHOLOGIC DESCRIPTION

LITHOLOGIC DESCRIPTION

Altered f i n e - g r a i n e d BASALTl i g h t o l i v e gray (5Y5/2)

SCORIACEOUS BASALT
Very f i n e grained. Plag. laths anddark mesostasis. C h l o r i t i c patches
occur.

Fine-grained medium gray BASALT (N5).

CHLORITE bearing fine-grained BASALT
Dark greenish gray (5GY4/1).
Few large vesicles (-3 mm diameter)
comprise about 1% of the bulk rock.
Clinopyroxene, Plagioclase andc h l o r i t e are the major c o n s t i t u e n t s .

A l t e r e d f i n e - g r a i n e d BASALTl i g h t o l i v e gray (5Y5/2)

Fine-grained medium gray BASALT (N5).

SCORIACEOUS BASALT
pale red (5R6/2)

0-4

VESICULAR BASALTS
Pale red (5R6/2) vesicles up to
1 cm in diameter.

VESICULAR BASALT
Medium dark gray (N4).
Plag. and clpx and dark mesostasis.

Fine-grained BASALT
medium gray (N5)

J 20

Core
Catcher

Explanatory notes in Chapter 1

General texture: P i l o t a x i t i c
Mineral content:
Plag. microphen.
1%
Plag. matrix
50%
Clinopyr.
3558
Dark mesostasis.
3%
Chlorite<3%
HematitetFe-oxide (Ht?)
7%
Altered fine-grained BASALTLight olive gray (5Y5/2).
Enriched in iron oxide andhematitic material.
A vein containing native copper
was seen at about 110 cm.
Texture: P i l o t a x i t i c to intersertal
Clinopyroxene
Phenocryst 1%
Plagioclase
Microph.
1%
Chlorite
MatrixHematite
Iron ore

Fine-grained medium gray BASALT (N5).

«t,« "β" Z , -Vesicular BASALT
Medium dark gray (N4).
AMYGDALAR BASALT
Medium dark gray (N4).
Chlorite, p l a g . , c l p x . , iron ore.
The amygdules are f i l l e d withcalcite.

Core
Catcher

Explanatory notes in Chapter 1

VESICULAR BASALT
Medium dark gray (N4).
Vesicles comprise about 15% of thebulk rock.

Site 216

Hole A

Core 1

Cored I n t e r v a l :101.5-111.0 m

Site 216

Hole A

Core 2

Cored I n t e r v a l :111 .0-120.5 m

LITHOLOGIC DESCRIPTIONWhite ooze, w i t hbands of f i n e
m a t e r i a l , andoccasional bluishwhite 5B9/1 bands.

S i t e 216

Hole A

Core 3

Cored I n t e r v a l . -120.5-130.0 m

S i t e 216

LITHOLOGIC DESCRIPTIONCore 4

Cored I n t e r v a l :130.0-139.5 m

LITHOLOGIC DESCRIPTION

CLAY FORAM RICH NANNO OOZE
l i g h t b l u i s h gray 5 B 7 / 1 , sharpc o n t a c t s w i t h adjacent l a y e r s
Clay20%
V o l e , glass2%
Micronodules
1%
Forams20%
Nannos
51%
Carb.
5%
Rads
1%
Sponge s p i c .
Tr.
Silicoflag.
Tr.

NANNO OOZEForamsNannosRads
Sponge s p i c .
ClayHole A

3%
85%
1%
1%
10%

Site 216

Hole A

Core 5

Cored Interval: 139.5-149.0 m

Site 216

LITHOLOGIC DESCRIPTION

Hole A

Core 6

Cored Interval: 149.0-158.5 m

LITHOLOGIC DESCRIPTION

SITE 216

216-1-1
238

216-1-2

216-1-3

216-1-4

216-1-5

216-1-6

SITE 216

216-2-1

216-2-2

216-2-3

216-2-4

216-2-5

216-2-6
239

SITE 216

216-3-1
240

216-3-2

216-4-1

216-4-2

216-4-3

216-4-4

SITE 216

0 cm

— 25

50

75

100

125

150

216-4-5

216-4-6

216-5-1

216-5-2

216-5-3

216-5-4
241

SITE 216

216-5-5
242

216-5-6

216-6-1

216-6-2

216-6-3

216-6-4

SITE 216

0 cm

25

50

75

100

125

150

216-6-5

216-6-6

216-7-1

216-7-2

216-8-1

216-8-2
243

SITE 216

216-9-1
244

216-9-2

216-9-3

216-10-1

216-10-2

216-11-1

SITE 216

216-12-1

216-12-2

216-13-1

216-14-1

216-14-2

216-14-3
245

SITE 216

216-15-1
246

216-15-2

216-15-3

216-16-1

216-16-2

216-16-3

SITE 216

216-17-1

216-17-2

216-18-1

216-18-2

216-18-3

216-19-1
247

SITE 216

0 cm

25

50

75

100

125

150

216-20-1
248

216-20-2

216-20-3

216-21-1

216-21-2

216-22-1

SITE 216

216-22-2

216-22-3

216-23-1

216-23-2

216-23-3

216-24-1
249

SITE 216

1
|

0 cm

1

25

T*

II

H
50

1
100

—125

!

'hi

LJ

y.
216-24-2

250

f

id

216-24-3

1

I

4r J

LJ

1 '1 1
1 ~J

150

Λ

fi

1H 0•
1
iI

— 75

π
1
j

V!

I
Wamm
216-24-4

1

i

•

p
T

1

[

|

Hi

j

JJ
|

A

216-24-5

1

J

LJ

LU

216-25-1

216-25-2

SITE 216
•O cm

25

50

75

100

125

150

216-25-3

216-25-4

216-26-1

216-26-2

216-26-3

216-27-1
251

SITE 216

0 cm

25

50

75

100

125

150

216-27-2
252

216-28-1

216-28-2

216-28-3

216-29-1

216-29-2

SITE 216

0 cm

25

50

75

h—100

125

150

216-30-1

216-30-2

216-30-3

216-30-4

216-30-5

216-31-1
253

SITE 216

0 cm

25

50

75

—100

—125

150

216-31-2
254

216-31-3

216-31-4

216-31-5

216-32-1

216-32-2

SITE 216

216-32-3

216-32-4

216-32-5

216-32-6

216-33-1

216-33-2
255

SITE 216

216-34-1
256

216-34-2

216-34-3

216-34-4

216-35-1

216-35-2

SITE 216

216-35-3

216-36-1

216-36-2

216-36-3

216-36-4

216-37-1
257

SITE 216

0 cm

25

50

75

100

125

150

216-37-2
258

216-37-3

216-37-4

216-38-1

216-38-2

216-38-3

SITE 216

0 cm

— 25

50

— 75

—100

—125

150

216-38-4
259

SITE 216

216A-1-1
260

216A-1-2

216A-1-3

216A-1-4

216A-1-5

216A-1-6

SITE 216

0 cm

25

50

75

100

125

150
216A-2-1

216A-2-2

216A-2-3

216A-2-4

216A-2-5

216A-2-6
261

SITE 216

0 cm

25

50

—100

125

150
216A-3-1
262

216A-3-2

216A-3-3

216A-3-4

216A-3-5

216A-3-6

SITE 216

0 cm

— 25

50

75

—100

—125

150
216A-4-1

216A-4-2

216A-4-3

216A-4-4

216A-4-5

216A-4-6
263

SITE 216

0 cm

25

50

75

—100

125

150
216A-5-1
264

216A-5-2

216A-5-3

216A-5-4

216A-5-5

216A-5-6

SITE 216

0 cm

25

— 50

75

100

125

150
216A-6-1

216A-6-2

216A-6-3

216A-6-4

216A-6-5

216A-6-6
265