4. SITE 213
The Shipboard Scientific Party1

ABSTRACTThe stratigraphic column at Site 213 is 154 meters in thickness
and contains four stratigraphic units with gradational contacts.
These units comprise an uppermost radiolarian-diatom ooze of
Quaternary to middle Miocene age, a nonfossiliferous zeolitic
brown clay, a nannofossil ooze of lower Eocene to upper
Paleocene age, and a basal iron-manganese oxide sediment
overlying weathered pillow basalt. Stratigraphic evidence isconsistent with a gradual deepening of the oceanic crustal plate
since its formation. The nonfossiliferous brown clay interval
midway down the hole may represent normal deep-basin sedimentation subsequent to the plate sinking below the carbonate
compensation level. The uppermost radiolarian diatom ooze
suggests the onset of high productivity, with only the siliceouscomponent being preserved below the carbonate compensationlevel and may reflect northward migration of the site into theequatorial productive zone. The oldest sediment age of 55 to 57
m.y. places an upper limit on the age of the beginning ofmagnetic anomaly 26.

SITE DATA
Date Occupied:
213: 4 Feb 72 (1800)
213A: 6 Feb 72 (1800)
Date Departed:
213: 6 Feb 72 (1800)
213A: 6 Feb 72 (1520)
Time on Site:
213: 48 hours
213A: 21 hours 20 minutes
Position:lat 10°12.7l'S
long93°53.77'E
Water Depth (to rig floor):
5609 meters (Echo sounding)5611 meters (Drill pipe)
Penetration:
213: 172.5 meters
213A: 130.5 meters
Number of Holes: 2l
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.

Number of Cores:
213: 19
213A: 3
Total Length of Cored Section:
213: 172.5 meters
213A: 24.5 meters
Total Core Recovered:213: 145.5 meters
213A: 24.5 meters
Acoustic Basement:
Depth: 154.0 meters
Nature: Basalt
Age of Oldest Sediment: Upper Paleocene
Basement: Basalt

BACKGROUND AND OBJECTIVES
The major piece of information governing the selectionof all three sites in the Wharton Basin was the identification
by Sclater and Fisher (in preparation) of lineated east-west
trending magnetic anomalies to the east of the Ninetyeast
Ridge. On the basis of this identification these authors
suggested that the Wharton Basin was formed from aneast-west spreading center which is either against the Java
Trench or has descended down the trench after the
cessation of spreading. The general topography of the basin
is accounted for by having large north-south trending
fracture zones offsetting the spreading axis progressively
northwards to the east of the Ninetyeast Ridge. This85

SITE 213

interpretation of the age and tectonics of the basin is
totally dependent on the correct identification of theanomalies east of the Ninetyeast Ridge as 23 through 33
getting older to the south.
Initially it was planned to drill close to anomaly 27 in asite surveyed during Scripps Institution of Oceanography
Cruise ANTIPODE XII. However, the sediment in the area
was too thin, and the site was moved further north to analternate site at 10°00'S, 93°57'E. This site is located in the
middle of a slight trough south of a 500-meter ridge which
stops the distal Nicobar Fan sediments on the eastern sideof the Ninetyeast ridge from penetrating further south(Figure 1). The ANTIPODE XII airgun record was of poor
quality, but was good enough to show that the troughconsists of a series of small basins 3 to 5 kilometers longcovered with flat-lying sediments of 0.1 to 0.2 sec
thickness. The incoming and outgoing airgun records(Chapter 10) are typical of the area.
The principal objective of the site was to date the age ofbasement and to help identify the magnetic anomalies. A
secondary objective was to obtain a stratigraphic andbio stratigraphic sequence east of the Ninetyeast Ridge. The
data from this site are to be compared with sections
recovered from sites on and to the west of the ridge. If thetectonic history as illustrated by the magnetics is correct,
then before the Eocene the oceanic crust on either side of
the ridge moved in opposite directions, and this difference
in motion may be reflected in the biostratigraphic,biogeographic, and paleomagnetic record.
OPERATIONS

Site 213 was approached in a northward direction along
the seismic reflection profile of ANTIPODE XII. Sedimentsin the area occur in what appear to be isolated basins, a few
kilometers in cross-section, within basement. The site wasselected in what appears to be a typical basin, containing
0.1 to 0.15 sec of acoustically transparent sediment
overlying a strong irregular basement reflector.
Due to the small size of the basin, the acoustic beacon
and a spar buoy were dropped underway at 5 knots, after
which the seismic gear and magnetometer were secured in
the normal way and the Challenger reversed course back tothe site. In order to drill in the deepest portion of the basin,
the drilling vessel was offset 1500 ft to the north of the
beacon. The chosen site is situated in 5611 meters of water(drill pipe to rig floor) at 10°12.75'S, 93°53.77'E. The site
was occupied on 4 Feb 72 at 1800 hours.
Soft siliceous oozes, red clays, and stiff chalks of Site
213 presented no drilling difficulties. The Smith 10,
1/8-inch bit from Site 212 was rerun. Basalt was reached at
a sediment depth of 154 meters and was drilled for 18.5
meters with a recovery of 45.4%. The hole was terminatedat a total depth of 172.5 meters. A total of 145.5 meters of
sediment and basalt was recovered, giving an overall
recovery of 84% (Table 1).
A second hole, 213A, was subsequently drilled offset
approximately 40 ft from the first. This hole was designed
to test the mechanical latching and electronic operation of
the temperature probe. Three mechanically successful
lowerings were made of the downhole instrument package,86

and temperature data were successfully gathered on the last
two. Three cores were taken from Hole 213A. A total of
24.5 meters of sediment was cored with 100% recovery(Table 2). Discussion of the heat flow results is given in
Chapter 14.
LITHOLOGIC SUMMARY

The total sediment section of about 150 meters wascontinuously cored and ranged in age from Quaternary tolate Paleocene. About 8 meters of weathered basalt werealso recovered from a penetration of 18 meters. The coredsequences have been divided into five lithologic units(Figure 2) as follows:

Unit
1
2

3
4
5

Depth
Below Sea
Floor (m)Lithology

0 to 75

Rad-diatom ooze
with varying clay
~70.5tol35 Zeolitic clay grading
towards nannobearing manganeseiron-oxide-rich dlay
~135 to 147 Nanno ooze
-147 to 152 Iron-oxidemanganese facies-154 to 172 Weathered basalt

Age

Cores

Quaternary
upper Miocene
Middle Miocene

1-8
8-15

Early Eocene
late Paleocene
?

15,16
16

?

17-19

Unit 1 — Radiolarian-Diatom Ooze (Cores 1-8)

Unit 1 consists of reddish yellow radiolarian-diatom
ooze. The diatoms and Radiolaria make up 50% to 75% and
12% to 40%, respectively, of the unit. The minor constituent is mainly a clay fraction averaging 7%. However,the clay content increases considerably near the top (35%)
and bottom (70%) of this unit. Among the other minor
constituents, iron-oxide minerals associated with manganese
micronodules are concentrated in thin layers and laminae inthe middle portion of the unit (Cores 3 and 6). Here theiron-oxide minerals are minute crystals with an oolitic
shape, reddish yellow color, with high relief and often
associated with purple red hematitic material. Volcanic ashof probably rhyolitic composition is also scattered throughout the unit with major concentrations (about 25%) andpumice being noted in Core 2 (upper Pliocene) and in Core
5 (late lower Pliocene).
Unit 2-Zeolitic Clay, Mn Iron-Rich at Base (Cores 8-15)
Unit 2 consists of zeolitic, brown clay. Well-crystallized
phillipsite is the main type of zeolite found. The zeolite
content varies from 1% to 7% in Cores 8,9, and 13 and ishigher elsewhere in the unit reaching a maximum of 20% in
Cores 11 and 12. Iron-oxide minerals and manganese
micronodules are concentrated in the lower part (Cores 12
through 15) of the unit where they make up about 15% of
the sediment. One concentration of volcanic ash ofrhyolitic composition was noted at the top of this unit. Thebase of Unit 2 grades into Unit 3 and consists ofinterbedded nannofossil ooze and clay, the latter containing

SITE 213

94C

Figure 1. Bathymetry in vicinity of Site 213.

87

SITE 213
TABLE 1
Coring Summary, Hole 213
Date
Depth from
Depth Below Length
Recovered Recovery
Core (Feb) Time Drill Floor (m) Sea Floor (m) Cored (m)
(%)
(m)
1

5

2

5

3

5

4

5

5

5

6

5

7

5

8

5

9

5

10

6

11

6

12

6

13

6

14

6

15

6

16

6

17

6

18

6

19

6

0805 5611.0-5620.0
1203 5620.0-5629.5
1335 5629.5-5639.0
1558 5639.0-5648.5
1635 5648 5-5658.01800 5658.0-5667.5
1930 5667.5-5677.0
2105 5677.0-5686.5
2230 5686.5-5696.00005 5696.0-5705.5
0140 5705.5-5715.0
0305 5715.0-5724.5
0440 5724.5-5734.0
0610 5734.0-5743.5
0730 5743.5-5753.00905 5753.0-5762.5
1145 5762.5-5770.5
1505 5770.5-5774.0
1800 5774.0-5783.5

0-9.0
9.0-18.5
18.5-28.0
28.0-37.5
37.5-47.0
47.0-56.5
56.5-66.0
66.0-75.5
75.5-85.0
85.0-94.5
94.5-104.0
104.0-113.5
113.5-123.0
123.0-132.5
132.5-142.0
142.0-151.5
151.5-159.5
159.5-163.0
163.0-172.5

Total

9

6.8

76

9.5

7.3

77

9.5

9.5

100

9.5

8.5

94

9.5

9.5

100

9.5

9.5

100

9.5

9.5

100

9.5

9.5

100

9.5

9.5

100

9.5

9.5

100

9.5

8.0

84

9.5

8.0

63

9.5

9.5

100

9.5

9.5

100

9.5

9.5

100

9.5

5.3

56

8.0

3.4

50

3.5

3.3

94

9.5

1.9

20

172.5

147.5

84

Note: Echo sounding depth (to drill floor) = 5609 meters;
drill pipe length to bottom = 5611 meters.
TABLE 2
Coring Summary, Hole 213
Depth from
Depth Below
Cored Recovered Recovery
Date
Drill Floor
Sea Floor
Core (Feb) Time
(m)
(m)
(%)
(m)
(m)
1

6

2

7

3

7

2200 5648.5-5656.00130 5724.5-5733.0
0440 5743.5-5752.0

Totals

37.547.0
113.5-122.0
132.5-141.0

7.5

7.5

100

8.5

8.5

100

8.5

8.5

100

24.5

24.5

100

Note: Echo sounding depth (to drill floor) = 5609 meters; drill pipe length to bottom = 5611 meters.

less iron-oxide-manganese constituents than above and nozeolite.
Unit 3—Nannofossil Ooze (Cores 15, 16)
Unit 3 is defined as the sediment section consisting onlyof pure nannofossil ooze (<10% clay only). The minor
constituents are authigenic carbonate (3%) and foraminifera(2%). Iron-oxide-manganese minerals only occur in trace
amounts.
Unit 4—Iron-Oxide-Manganese Facies (Core 16)
This unit comprising the lower part of Core 16 consists
entirely of iron-oxide-manganese facies. The iron-oxidematerial is made up of oolitic-like crystals (geothite?)
associated with red scales of hematitic and less crystalline
masses of limonitic material. Micronodules and aggregatesof manganese were also seen. The only other mineraloccurring in significant amounts in this facies is palygorskite (detected by X-ray diffraction).
Unit 5-Basalt (Cores 17-19)
Unit 5 consists of a succession of at least 11 basaltic
flows. Each flow is a pillow-lava with chilled margins.
Within each flow three different zones are identified: ( l ) a
glassy palagonatized margin, (2) a weathered porphyritic
basaltic zone, and (3) a more crystalline and less weatheredbasaltic zone. A thin film of manganese was noticed insome fragments near the top of Unit 5. The generalmineralogy consists of Plagioclase, clinopyroxene, palagonite, iron-oxide minerals, calcite, silica aggregate, and adark mesostasis. The texture varies from variolitic to
subophitic.

SITE 213
TABLE 3
Shipboard Chemistry Results

SITE 213
10°12.7'S 93°53.8'E
5611m
QUAT.

Core,
Section,Interval
(cm)

1
.2

UPPER

3

PLIO.

4

L.PLIO.5

Rad Diatom
Ooze

6
UPPER

7

MIOC.

8
9

M.MIOC. 10
11
12

-70.5

Zeolitic
Clay

-100

13
14
L.EOC.15

Clay, Ooze -135
Nanno Ooze
Clay
Nanno Ooze -154
Fe-Mn

Pillow Lava
BasaltT.D. 172.5 m; 19 cores;
145.5 m rec.

Figure 2. Lithologic units at Site 213.
CHEMICAL PROPERTIES

Ten samples were collected from the 16 cores whichcontained sediments. Two contiguous 10-cm minicores
were taken from the top of the selected core section in allcases excepting Samples 213-2-5 and 213-16-4 when only
one was removed. Samples were held at 4°C until processing. One minicore was used for resistivity measurements,
then removed from the liner, scraped to remove contamination, and loaded into the squeezer. Sufficient time wasallowed for the sediment to reach ambient room temperature before extraction of the pore fluids. The otherminicore was used for punch-in pH measurements, thenpreserved for shore-laboratory studies. Complete shipboard
results are given in Table 3.
BIOSTRATIGRAPHIC SUMMARY
GeneralSite 213 was cored continuously from the sea floor to
the acoustic basement, which was encountered at a depthof approximately 152 meters. The sequence can conveniently be divided into three lithologic units. Transitions
between these major units occur over intervals of several
meters.
The upper unit (Cores 1 through 8) is a siliceous ooze
with abundant diatoms and common radiolarians. Diatoms
are in greatest abundance near the top of the unit anddecrease in abundance downward. This unit contains anapparently uninterrupted sequence from the Recent into
the late Miocene. At the lower part of the unit (Cores 9 and

1-0
1-1,691-1,140
1-3,20
1-4,402-3,102
2-5,0
2-5,120
3-3,130
3-5,0
4-1,71
4-5,55
5-1,65
5-5,0
6-3,70
6-6,507-5,08-3,14
8-6,14
9-6,0
9-6,85
10-3,75
11-3,30
11-5,013-6,014-2,77
14-6,90
15-5,102
15-6,016-4,016-4,34
16-4,140pH(flow-through)pH(punch-in)

Water
(%)

Porosity(%)

Density(gm/cc)

7.29

7.16

6.92

7.15

7.29

7.12

70
71
73
71
72
68
68
71
69
70
59
69
61
62
67
67
69
67
67
63
66
65
56
54
54
53
35
33
31
29
31
52

86
90
91
90
90
88
90
91
93
90
79
89
83
86
90
87
91
88
88
87
89
87
76
79
82
80
62
56
56
55
58
71

1.23
1.26
1.25
1.27
1.24
1.29
1.32
1.29
1.34
1.28
1.33
1.29
1.35
1.39
1.34
1.34
1.31
1.31
1.30
1.37
1.34
1.34
1.35
1.46
1.53
1.50
1.76
1.72
1.82
1.88
1.85
1.36

-

6.97
_

6.94
-

7.11
-

6.80

7.09

6.92

-

-

7.04
7.16
-

too stiff
too stiff

7.30
7.29

7.52
7.49

:

-

10) the radiolarian specimens become increasingly morecorroded. Below Core 10 radiolarians are absent entirely.
Underlying the siliceous ooze is an unfossiliferous
zeolitic clay, which represents much of the depositional
history of the area (from early Eocene to middle Miocene).
The lowermost unit consists of interbedded nannofossil
ooze and iron-rich clay of early Eocene and late Paleocene
age. Approximately 5 to 10 meters of unfossiliferous clay
overlies the acoustic basement. There is one recognizable
unconformity within the cores obtained; the Cannartus petterssoni (radiolarian) Zone (within the middle Miocene)
may be missing.
Foraminifera
Cores 4 to 6 contain sporadic deep-water benthonicassemblages. Single specimens of Morozovella aff. spinulosa,
Acarinina aff. primitiva, "Globorotalia " aff. pseudomayeri,
and one fragment of Globigerapsis or "Globigerinoides"
higginsi are sufficient to indicate a middle Eocene age forthe clays of the Core 11 CC to Core 13 CC interval.

89

SITE 213

There is a downward increase in total assemblage in Core
14 from fish teeth and agglutinated benthonics (Sections 1,2) through very rare planktonics (Sections 3, 4) andcalcareous benthonics (Sections 5 and upper part of 6) to aplanktonic assemblage (lower part of Sections 6 and CC). In
the latter, specimens are corroded, fragmented, and recrystallized.
This planktonic assemblage is richer in specimens andmore diverse in Core 15 (Sections 1 to 3) where the"Globorotalia"formosa Zone (P.7) is recognizable.
There is a change within Core 15, Section 4: a distinctly
different, better preserved and even richer assemblage from
Section 5 to CC is identified as the Morozovella subbotinae/
Pseudohastigerina wilcoxensis Subzone (P.6b).
There is another change between Sections 15, CC and16-1. Core 16 contains a rich, excellently preserved
assemblage with abundant Morozovella velascoensis andvery few of the M. subbotinae/gracilis/marginodentatal
pasionensis group, in both respects being in sharp contrast
with Core 15. Core 16 is identified as the Morozovellavelascoensis Zone (P.5) and, on negative evidence, isassigned to the upper part of that zone. Core 16, CC
contains a mixed Paleocene and Eocene assemblage due tocontamination.
The limits of this three-part calcareous section are
estimated to be approximately 51 and 55 m.y.
Material removed ultrasonically from the surface of the
top four pieces of basalt in Core 17 yielded smallbenthonics and small planktonics in two distinct preservations. All of the planktonics could be downhole contaminants; if they were in situ, they would give a maximum ageof 57 to 58 m.y.
Nannofossils
Calcareous nannofossils of early Tertiary age wererecovered in Cores 14, 15, and 16. In addition, nannofossils
were also recovered from the surfaces of basalt fragments
near the top of Core 17. The highest occurrence of
nannofossils is in Core 14, Section 5, which contains asparse assemblage consisting primarily of Discoaster lodoensis and Tribrachiatus orthostylus. The cooccurrence of
these two species indicates an early Eocene age (Tribrachiatus orthostylus Zone = ~52 m.y.) for this interval. Thissame assemblage, with progressively more species added,
continues to Core 15, Section 4. Discoaster lodoensis is notpresent below this level, but Tribrachiatus orthostylus andDiscoaster diastypus cooccur as far as the bottom of Core
15. The interval from the middle of Section 6, Core 14 to
the bottom of Core 15 is assignable to the early Eocene aswell {Discoaster diastypus Zone of Bukry, 1971).
All of Core 16 is assignable to the late Paleocene Discoaster multiradiatus Zone. The core-catcher sample forCore 16 is contaminated as it contains a mixture of latePaleocene and early Eocene elements.
One additional age assignment can be made—and that isfor the calcareous material scraped from basalt fragmentsfrom near the top of Core 17. The assemblage from thismaterial contains, among others, Cyclococcolithina robusta
and Sphenolithus anarrhopus with few asteroliths of the

90

Discoaster omatus type. Only one specimen of Discoastermultiradiatus was encountered, and this is probably a
contaminant. Only a relative age assignment can be madefor this sample. It is slightly, but distinctly, older than theoldest material recovered in Core 16. The nannofossil
assemblage has an oceanic aspect with normal diversity
except at the top and bottom of the calcareous interval,
where the number of species is much reduced and theremaining specimens show strong evidence of solution/
corrosion.
Radiolaria

Radiolaria ranging in age from Quaternary to middle
Miocene are present in Cores 1 through 10 at Site 213. In
Cores 1 through 8 Radiolaria are common and wellpreserved. In Cores 9 and 10 Radiolaria are increasingly
more corroded downward, and the orosphaerids and collosphaerids are the predominant forms present.
The following faunal boundaries can be recognizedwithin the siliceous ooze section of the cores:
The base of the Quaternary is between Samples 213-2-3,
100-102 cm and 213-2-4, 90-92 cm. The base of the
Pterocanium prismatium Zone is between Samples 213-3,
CC and 213-4-2, 105-107 cm. The base of the Spongasterpentas Zone is between Samples 213-74, 60-62 cm and213-7, CC. The base of the Stichocorys peregrina Zone is
between Samples 213-8-6, 100-102 cm and 213-8, CC. The
Ommatartus penultimus Zone is represented at Sample
213-8, CC. Material between Samples 213-9-1, 140-142 cm
and 213-9-6, 73-75 cm is within the Ommatartus antepenultimus Zone. The material in Sample 213-9, CC lies
within the lower Cannartus petterssoni Zone or upper
Dorcadospyris alata Zone. Radiolaria are absent below
Sample 213-10-1, 70-72 cm.
CORRELATION OF REFLECTION PROFILEAND STRATIGRAPHIC COLUMN

Sediment cover in the region of Site 213 is sparse, withsediment mainly occurring in small "basins" a few miles inlength within rugged basin topography. The actual drill site
was chosen in a typical basin which contains a maximum of
0.14 to 0.16 sec of sediment over basement.
The seismic profile of the site (Figure 3) shows thesediment to be acoustically highly transparent throughout
the entire section. Acoustic basement is topographicallyrough, and from the figure it is apparent that the drill site
was chosen in a basement "valley" over which about 0.16
sec of sediment occurs.
The only positive correlation possible in this area is thatof acoustic basement, depth 0.16 sec, and basalt, at a
drilled depth of 154 meters. This correlation gives aninterval velocity to the sediment of 1.9 km/sec. From thestratigraphic column it is evident that the acousticallytransparent sediment corresponds with monotonous
massively bedded units of siliceous ooze, zeolitic brown
clay, and stiff calcareous ooze.
Depths of reflectors and interval velocities are as
follows.

SITE 213

SECS
7

SITE 213

toH•A

meters0

Siliceous ooze to clays i l i c e o u s ooze

-8Z e o l i t i c brown clay
100-h-ry-_-_r-_-

Calcareous ooze
J3rown_ cl_ay_
Basalt-9

Nautical Miles
0
Figure 3. Correlation of reflection profile and stratigraphic column at Site 213.

Reflector

2-Way Time (sec)

Depth
(m)

0

9

0.16

154

Interval Velocity(km/sec)
1.9

SUMMARY AND CONCLUSIONS

Site 213 was chosen at a point approximately 500 km
east of the Ninetyeast Ridge. It was drilled close to thebeginning of anomaly 26 identified by Sclater and Fisher(in preparation).

91

SITE 213

The site was drilled in a small basin approximately 6
miles in length which contains a maximum of 0.14 sec of
acoustically transparent, apparently ponded sediment.
Water depth is 5601 meters. The site typifies the region, so
far as can be deduced from the seismic profile. To the northand south the basement is rugged and includes several
similar basins.
The basal unit is a weathered pillow-basalt with distinct
mid-Indian Ocean ridge affinities. Approximately 2.5
meters of section, possibly calcareous ooze, is missing fromjust above the basalt, but upper Paleocene calcareous ooze
adheres to the uppermost basalt fragments. Above the zoneof missing basal sediment lies an iron-oxide-rich clay whichis overlain by and partly interbedded with a calcareous
nannofossil ooze unit of late Paleocene to early Eocene
age. The main unit at this site is a zeolitic clay and theupper lithologic unit is a Quarternary to upper Miocene
radiolarian-diatom ooze.
Foraminiferal and nannofossil assemblages in the calcareous section near the bottom of the hole have a low
latitude oceanic aspect. Towards the top of the calcareousunit where it grades into overlying red clay, a residual floraand fauna composed only of the most resistant forms ispresent, indicating the onset of dissolution.
At the time of the formation of oceanic crust at Site
213, the area was situated above the regional carbonate
compensation depth as a sea-floor spreading center andremained so until early Eocene as evidenced by accumulation of biogenic carbonates. The ridge then slowly subsided
below the carbonate compensation level during spreading,resulting in a gradual diminution of the carbonate supply tothe sea floor. The resulting lack of diluting biogenous
material would then favor the accumulation of nonfossiliferous zeolitic brown clay facies. During late Miocene, theplate moved northwards into equatorial high productivity
regions so that brown clay sediments became swamped withbiogenous material. Because the plate has subsided below

92

the carbonate compensation depth, noncalcareous radiolarian diatom ooze began to accumulate and has persisted
to the present.
The weathered basalts below the sediments are similar incomposition to those from the active mid-Indian Ocean
ridges. The presumed basement contact was continuously
cored, and nannofossils were recovered in Core 17 adheringto the basalt which gave an age of 55 to 57 m.y.
Foraminifera were recovered to the bottom of Core 16 andwere located in the P.6a (54 m.y.) Zone of Berggren(1971). However, material removed ultrasonically from thebasalt in Core 17 gave a maximum downward age of Zone
P.4 or 57 to 58 m.y. The magnetic anomaly identification isclear and is the beginning of 26 giving a magnetic age from
Heirtzler et al. (1968) of 64 m.y. This is 6 to 7 m.y. morethan the oldest sediment, and together with ttie resultsfrom Legs 3 and 5, is evidence that the magnetic andbiostratigraphic scales are significantly different. As aresult, a special chapter (Chapter 13) has been devoted inthis report to the correlation between the two time scales.

REFERENCES
Berggren, W. A., 1971. A Cenozoic time-scale: some
implications for regional geology and biogeography. J.
Foram. Res., v. 1.
Bukry, D., 1971, Cenozoic Calcareous nannoplankton fromthe Pacific Ocean: San Diego Soc. Nat. Hist. Trans, v.
16, p. 303.
Heirtzler, J. R., Dickson, G. O., Herron, E. M., Pitman, W. C, III, and LePichon, X., 1968. Marine magnetic anomalies, geomagnetic field reversals, and motionsof the ocean floor and continents: J. Geophys. Res.,v. 73, p. 2119.
Sclater, J. G. and Fisher, R. L., in preparation. The
evolution of the East Central Indian Ocean withemphasis on tectonic setting of Ninetyeast Ridge.

Site 213

Hole

Core 1

Cored I n t e r v a l : 0 - 9 m

Site 213

LITHOLOGIC DESCRIPTION

Abundantly mottled with l i g h t
brown (7.5YR4/4) clay rich raddiatom ooze. The diatom content
increases with depth (up to52%) diatom.
and micronodules in streaks

and patches occur throughout.
Bottom contact transitional towards
a diatom rich zone.
Firmer reddish yellow (7.5YR6/8)
RAD DIATOM OOZE
Diatoms
47-49%
Rads
36-40%Clay
5-10%
Spicules1 - 5%
Silicoflag.
1%
Glass, clear
1 - 2%
Feldspar1%
Fe oxide minerals
1%
Abundantly mottled with medium
brown (7.5YR4/4) clay r i c h raddiatom ooze and with dark brown(7.5YR3/0) manganese r i c h raddiatom ooze.
LAMINAE-like zone, of MANGANESERICH RAD DIATOM OOZE, dark brown(7.5YR3/0), occur throughout.
Mn0× micronodules
14%
Diatoms
Rads
Clay

Core 2

Cored I n t e r v a l : 9-18.5 m

LITHOLOGIC DESCRIPTION

S o f t , DIATOM RICH RAD CLAY
medium brown (7.5YR4/4)
Clay
3556
Rads
34%
Di atoms
20%
Spicules5%
Fe oxide minerals
2%Silicoflag.
IX
Feldspar1%
Volcanic glass
1%
Mn0× Micronodules
1%

MO

Hole

60%
10%
16%

These laminae occur a t Section 3(50-55 cm), Section 3 (98-110 cm)
and Section 4 (30-45 cm).
Intermixed layers o f reddish
yellow (7.5YR6/6) CLAY BEARINGRAD DIATOM OOZE
Quar 28, Feld 4 , Plag 12, Kaol 15,
Mica 24, Mont 17
Intermixed layers (due to corer)
reddish yellow (7.5YR6/6) clay
oearing diatom ooze.
Quar 3 1 , Plag 14, Kaol 19, Mica 25,
Mont 11
Quar 36, Plag 1 1 , Kaol 2 1 , Mica 24,
Mont 8Light brown reddish yellow(7.5YR6/5) RAD RICH DIATOM OOZE
Diatoms
70%
Rads
20%
Cl ay
5%
Volcanic glass
2%
Silicoflag.
2%
Spicules1%
Commonly laminated in Sections
1 and 2 with dark brown (7.5YR4/3)
CLAY SPONGE SPICULE RAD BEARING
Diatoms
49-79%
Clay
5-10%
Rads
7-10%,and pale grayish blue green(5BG7/2) LAMINAE of RAD VOLCANICASH RICH DIATOM OOZE (ash 10-25%).
The volcanics are mainly glass
shards o f r h y o l i t i c composition,
laminations decreases w i t h depth
and disappear i n Section 3 below
80 cm.
M o t t l i n g occurs throughout the core.
X-ray a t 15.30 m Quar 3 1 , Feld 4 , Plag 15, Kaol 16,
Mica 23, Mont 11
X-ray at 15.50 m Quar 35, Plag 12, Kaol 18, Mica 23,
Mont 13

Cored I n t e r v a l : 1 8 . 5 - 2 8 m

S i t e 213

Hole

Cored I n t e r v a l . 2 8 - 3 7 . 5 m

FOSSILCHARACTER

LITHOLOGIC DESCRIPTION

LITHOLOGIC DESCRIPTION

Fe>•Mn7.5YR5/2

7.5YR5/2£ej!nReddish y e l l o w (7.5YR8/5)
RAD RICH DIATOM OOZE.
Diatoms
75%
Rads
16%
Clay
2 - 3%
Glass
1%
Mn0x
It

Reddish yellow (7.5YR7/5) RAD
RICH DIATOM OOZE.
Diatoms
65-75%
Rads
12-25%Clay
5-10%
Spicules1 - 5%
Silicoflag.
<1%
Interlayered with mottled zones
of medium brown (7.5YR5/2)
manganese Fe-oxide bearing radrich diatom ooze (Fe-oxideminerals 3% M 0v <5%).

SpiculesSilicoflag.

7.5YR5/2

Below Section 3 the core is badly
disturbed and intermixing ofreddish yellow and dark brown
sediment similar to the above
sections occur.

Volcanic ash increase in Section 3(volcanic 3%) in the reddish
yellow clay bearing rad richdiatom ooze.

— pumice

X-ray at 26.10 m Quar 26, Plag 8, Kaol 19, Mica 30,
Mont 17

7.5YR5/2

Laminated zone of manganese ironenrichment very dark brown(7.5YR2.5/2) Section 6 (10-30 cm).
Clay rad rich diatom ooze
Clay
Di atoms

Explanatory notes in Chapter 1

20%
45%

Rads

25%

Silicoflag.
Spicules
Glass
MJ)..

5%
1%
2%
2%

1%
1%

Interlayered with dark brown(7.5YR3/2) manganese Fe-oxidemineral bearing rad rich diatom
ooze.

Explanatory notes in Chapter 1

Site 213

Hole

Core 5Site213

Cored Interval.37.5-47 m

LITHOLOGIC DESCRIPTION

Reddish yellow (7.5YR7/5) RAD
RICH DIATOM OOZE, similar tocore number 4, mottled withbrown (7.5YR3/2) manganeseFe-oxide aggregate clay bearing
rad rich diatom ooze.

Most of the core is moderately
disturbed and intermixing of
sediment occur.

The s i l i c o f l a g . are more abundant
than in previous cores (=5%).

Hole

Core6

Cored Interval ;47-56.5 m

LITHOLOGIC DESCRIPTION

Reddish yellow (7.5YR7/7) RAD
RICH DIATOM OOZE
Diatoms
70%
Rads
15-20%Clay5%
Spicules2- 5%
Silicoflag.
2%
Ash
1%
Mottled w i t h g r a y i s h brown
MANGANESE BEARING CLAY RAD RICH
DIATOM OOZE
Diatoms
51*
Rads
25%
Clay
15*
M

n°x

3%

Glass
2%
Others (Fe-oxideminerals)4%
Caused by disturbance (due tocorer) most of the core isintermixed with reddish yellow
and grayish brown sediment
similar to above.

Site213

Hole

Core 7Site213

Cored Interval:56.5-66 m

LITHOLOGIC DESCRIPTION

π°x

Silicoflag.
SpiculesFe-oxide minerals
Feldspar
Glass

Coreδ

Cored Interval:66-75.5 m

LITHOLOGIC DESCRIPTION

Reddish yellow (7.5YR7/7)
CLAY RAD RICH DIATOM OOZE.
Diatoms
51-56*
Rads
20-25%
Clay
15?
M

Hole

Z%

2*
1*
2%
1%
1 - 3%

Mottled with l i g h t olive brown(2.5Y5/4) ASH BEARING CLAY RAD
RICH DIATOM OOZE. Small patches
enriched in manganese aggregates
scattered throughout the core.
A small pocket of white VOLCANICASH occur in Section 3 at 70 cm.

Medium dark brown (7.5YR4/2)
SPONGE SPICULE DIATOM RAD RICH
CLAY
Clay
672!
Diatoms
10*
Rads
10*
Spicules10*
Silicoflag.
U
Glass
2*
ZeoliteTr.
Intermixed (due to coring disturbance) with reddish yellow(7.5YR6/6) rad rich diatom ooze
similar to Core number 7.

This medium dark brown layer
grades into a darker brown layer.
The contact appears to be gradational .

Dark brown (7.5YR3/2) CLAY
Clay
92%
Rads
3%
Spicules
2%
Glass
IX
Zeolite1%M

n°xBlack streaks of manganeseaggregates occur
throughout Section 4.

nSite 213

Hole

Core 9

Cored Interval:75.5-85 m

Site213

LITHOLOGIC DESCRIPTION

HoleCorelO

Cored I n t e r v a l :85-94.5 m

LITHOLOGIC DESCRIPTION

Dark brown (7.5YR3/2) MANGANESEZEOLITE BEARING CLAY
Clay
86%
Zeolite
3%
M

n°x

Rads
Fe-oxide minerals
Spicules
Feldspar

3*

3%
2%
1%
1 - 2%

There is a s l i g h t increase i n
Fe-oxide minerals with depth.
These minerals are reddish
yellow and have an o o l i t i cshape (goethite ?).

Dark brown (7.5YR3/2) CLAY
similar to the lower half ofCore 8, grades towards a darkbrown (7.5YR3/2) zeolite richclay.

Dark brown (7.5YR3/2) ZEOLITE
Clay
82-84%Rads
1 - 3%
Zeolite ( P h i l l i p s i t e ) 3-10%
Mn0x
1 - 2%
Fe-oxide mineralsGlass

1 - 3%
1%Fe-oxide mineral showso o l i t i c shape (may be
g o e t h i t e ?)The manganese aggregate content
increase s l i g h t l y w i t h depth up
t o about 3%.
X-ray a t 83.80 m Quar 1 3 , Feld 1 1 , Plag 6 , Kaol 1 1 ,Mica 13, Mont 36, Phil 10

MANGANESE FE-OXIDE AGGREGATE
BEARING ZEOLITE CLAY
Clay
65-77%
Zeolite5-25%
Mn0x
1 - 3*
Fe-oxide minerals
Rads
Spicules2 - 5%
1 - 5%
1%

X-ray at 88.70 m Quar 14, Plag 9, Kaol 14, Mica 9,Mont 37, Phil 15

Site213

Hole

CorellCored I n t e r v a l : 9 4 . 5 - 1 0 4 m

Site213

Corel2

Cored I n t e r v a l : 104-113.5 m

LITHOLOGIC DESCRIPTION

LITHOLOGIC DESCRIPTION

Dusky yellow brown (10YR2/2)
MANGANFSF BFARTNG ZEOLITE RICH
CLAY
Clay
67-79%
Zeolite15-25%
M
3- 6%
n ° x aggregates
Fe-oxide minerals
Feldspar

Hole

2%
U

The content of z e o l i t e seems to
be constant throughout the core.

X-ray at 99.70 m Quar 9, Feld 5, Plag 6, Kaol 4 ,Mica 7, Mont 15, Paly 14, Phil 38,
Amph 1

Dusky brown (5YR2/2) MANGANESEBEARING FE-OXIDE MINERAL andZEOLITE RICH CLAY
Clay
59%
Zeolite202!
Fe-oxide mineral(goethite ?)15%
Feldspar
<U
M

n°x

<1M

Site 213

Hole

Corel3Site 213

Cored Interval:113.5-123 m

LITHOLOGIC DESCRIPTION

Dusky brown (5YR2/2) MANGANESE
FE-0X1 DE MINERALS and ZEOLITE
RICH CLAY
Clay
73-84%
Zeolite3-10%Fe-oxide minerals(goethite ?)13-20%Glass
Tr.

The i r o n oxide minerals are
reddish yellow, with highr e l i e f , opaque and o o l i t i cshaped (goethite ? ) .

HoleCorel4

Cored Interval :123-132.5 m

LITHOLOGIC DESCRIPTIONLight brown (5YR5/6) FE-OXIDEMINERAL RICH CLAY
Clay70%
Fe-oxide minerals
30%
Nanno
Tr.
Transitional contact.

Moderate brown (5YR3/4)
MANGANESE BEARING FE-OXIDEMINERAL RICH CLAY
Clay78%
Fe-oxide
15%
M

n°x

3%

Nanno
Rads

3%
1%

The main type of z e o l i t e isphilipsite.

The zeolite content decreases
with depth in the core. In
Section 6 there is only about
3-4% zeolite.

X-ray 117.20 m Quar 10, Feld 10, Mica 7, Mont 5,
Paly 20, Phil 47

Interbedded w i t h moderate
yellowish brown (10YR5/4)
CLAY RICH NANNO OOZE andbecoming less clayey withdepth.
Nanno
70-85%
Clay
10-25%Rads
U
Fe-oxide
<T.%
M

n°x

<2%

Calcite1 - 3%

Moderate yellowish brown (10YR5/4)
CLAY BEARING NANNO OOZE
X-ray at 125.20 m Quar 13, Feld 25, Kaol 1 , Mica 13,
Chlo 2, Mont 10, Paly 35ooCored Interval:132.5-142 m

Site 213

Cored Interval.142-151.5 m
FOSSILCHARACTERFOSSILCHARACTER

LITHOLOGIC DESCRIPTION

1.0- ;_-_-_-_-_-_-_-

I-I-I-I-I-I-IFe

LITHOLOGIC DESCRIPTION

Moderate brown (5YR3/4) NANNOMANGANESE BEARING FE-OXIDEMINERAL RICH CLAY s i m i l a r toCore number 14.

Yellow ( 2 . 5 Y 7 / 6 ) NANNO OOZE
S i m i l a r t o Core number 15 andhomogeneous down t o S e c t i o n 4 .

In Section 2 t h i s sediment i sintermixed (due to coringprocess) w i t h moderate yellowish
brown (10YR5/4) clay bearing
nanno ooze.

Yellow (2.5Y7/4) CLAY BEARINGNANNO OOZE
Nanno
85%
Clay
IM
Rads
1%
Foram
U
3%
CalciteTransitional bottom contact due
to the increase i n clay and Iron
oxide m a t e r i a l .

Interbedded w i t h moderate brown(5YR3/4) nanno bearing Fe-oxidemineral r i c h clay s i m i l a r t oCore number 14.
Burrow mottled.

Grayish brown (5YR3/2) CLAY RICH
IRON OXIDE SEDIMENT
Clay
9-1855Iron ore
80-85%Nanno
1 - 3%
Auth. carb.
0- 2*

X-ray at 144.60 m Calc 100
X-ray a t 147.90 m Calc 12, Quar 1 1 , Feld 15, Kaol 4 ,Mont 3, Paly 54

Yellow (2.5Y7/6) NANNO OOZE
Nanno
98%
Foram
2%
Auth. carb.
3%
Clay
10S
Fe-oxide m i n e r a l . Manganeseand g l a s s occur i n t r a c e s .
Explanatory notes in Chapter 1

Core
Catcher
Explanatory notes i n Chapter 1

Grayish brown (5YR3/2) CLAY
BEARING IRON OXIDE SEDIMENTl i m o n i t i c aggregates and manganese comprise about 40%,o o l i t i c Fe-oxide 45%, clay 9%,
and nanno 3%.

Site213

Hole
FOSSILCHARACTER

Corel7

Cored Interval;151.5-159.5 m

Cored Interval :163-172.5 m
FOSSILCHARACTER
LITHOLOGIC DESCRIPTION

LITHOLOGIC DESCRIPTION

2.5 m gap between the basalt
and the above cored sediment.
The first rock fragments near
the top were coated with nanno
ooze.
(a) light brown (5YR5/6)
WEATHERED BASALT, phenocrysts of Plagioclase are
set into a fine grained
weathered matrix. This
zone grades into a moreglassy area.

(a) Light brown (5YR5/6)
WEATHERED BASALT.
Partially(b) BASALTIC GLASS rimed witha palagonite crust

Vesicular zone
(1-5 mm diameter)(c) light olive gray (5Y6/1)
partially WEATHERED
PORPHYRITIC BASALT.
General mineralogy:
Dark mesostones
40%
Plag. phen.
1%
Plag. microphen.
2%
Plag. laths(intermediate size)
255!
size)
i)

Thin sect, atSection 2,
80 cm.

Core
Catcher

Plag. microHtes
Skeletal pyrox.
Palagonite
Olivine outlined
phenocrysts
CalciteCore
Catcher103152!

(c) Light olive gray (5Y6/1)
coarse grained BASALT.
General mineralogy:
Thin sect, at
Plagioclase
126 cm,Clinopyroxene
Section 2.
Iron oxide minerals
Cryptocrystalline
s i l i c a aggregates
Palagonite

5%
IX
U

Cored Interval:159.5-163 m
General texture: subophitic.
The interstices of Plagioclase
are filled with granules ofpyroxene, silicoflag.
aggregates and iron oxideminerals.

LITHOLOGIC DESCRIPTIONThis zone appears to be coarser
grained and more crystalline thanCore number 17 Section 2.
(a) Light brown (5YR5/6)
WEATHERED BASALT.
(b) BASALTIC GLASS partially
PALAGONITIZED.
(c) Light olive gray (5Y6/1)
partially WEATHERED BASALT.
This zone appears usuallyless weathered than (a).
(d) Very fine grained grayish
brown (5YR3/2) soft andextremely oxidized material.

Explanatory notes in Chapter 1

Explanatory notes in Chapter 1

SITE 213

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