6. site 1122: turbidites with a contourite foundation€¦ · shipboard scientific party chapter 6,...

SHIPBOARD SCIENTIFIC PARTYCHAPTER 6, SITE 1122: TURBIDITES WITH A CONTOURITE FOUNDATION 57

Figure F16. Biostratigraphic summary chart of Site 1122 showing correlation between the four microfossilbiohorizons and age assignments. Numbers are ages (Ma).

Site 1122

0

100

200

300

500

Dep

th (

mbs

f)

Gr. puncticuloides 0.7-0.8

DIATOMS RADIOLARIANSNANNOFOSSILS

PLE

IST

OC

EN

E

AgeFORAMINIFERS

400

600

MID

DL

E M

IOC

EN

E

Gr. hirsuta 0.45

3.8

T. elliptipora 0.65-0.7

N. continuosa 11

Gr. praemenardii 13.2

Gr. zealandica 16.7

H. karstenii (Acme) 0.42

H. karstenii 0.18-0.19

A. ingens 0.64

E. huxleyi 0.24

P. lacunosa 0.42

R. asanoi 0.85

R. asanoi 1.16

G. parallela 0.95

Gephyrocapsa (large) 1.2

1.2

1.44

Gephyrocapsa (medium) 1.72

~ 3.54

>10.4 C. miopelagicus LO

<17.4 C. premacintyrei FO

C. macintyrei 12.34

S. heteromorphus 13.52

S. universus 0.46

E. calvertense 1.92

L. nautiloides 1.93PLIOCENE

S. barboi 12.5

N. denticuloides11.3-12.7

D. dimorpha 12.2

Dissolution facies; only reworked

Paleocene diatoms present

Miocene species present

LATE

EARLY PLIOCENE

?

< 2.6

Gr. miozea 15.9


Figure F17. Age-depth curve using multiple microfossil and polarity chron datums for Hole 1122C. Thebest fit line is drawn according to subjective weighting of the chronostratigraphic and geochronologic pre-cision of the events and approximate average rate of sedimentation. Numbers by datums (e.g., F1) denoteevents listed in Table T8, p. 127. Wavy line at 490 mbsf represents a stratigraphic disconformity.

N13

F6

0 1 2 3 11 12 13 14 15 16

0

100

200

300

400

500

600

N1

F1

N2

R1

D3

D4

N6

F3 N9

D6

F4

D7 N12

D1

N5

N4

F2

N7

N8

R2

D2

N3

N10D5

N11

R3

Sed. Rate= ~400 m/m.y.



F5

Age (Ma)

Tephra

Tephra

TephraTephra

Tephra

Tephra

4 5 6 7 8 9 10

Dep

th (

mbs

f)


Figure F18. Summary of the changing characteristics of the foraminiferal faunas at Site 1122.

Litho-stratigraphic

Unit

PlanktonicFauna

BenthicFauna

ABC

D

Normal,well-preserved,oceanic fauna

Deep-water assemblagewith addition of smallshelf and bathyal forms

Normal,well-preserved,oceanic fauna

Only deep-waterassemblage

ALarge, thick-walled,oceanic fauna, few orno small forms

Only deep-waterassemblage

Barren or rapidlyburied fauna of smallforms (winnowings) - minor reworkedOligocene

Barren or only deep-water assemblageB

Variable oceanic fauna

Only deep-waterassemblageA

Normal oceanicfauna

Dominantly mid-shelffauna (large and small) with minor deep-water assemblage

Tur

bidi

te-

dom

inat

edC

onto

urite

-dom

inat

ed

B

Deb

ris fl

ows

and

coar

se s

edim

ents

UN

IT I

UN

IT II

UN

IT II

I

Dis

solu

tion

Mio

cene

Plio

cene

-Ple

isto

cene

SH

IPB

OA

RD

SC

IEN

TIFIC P

AR

TY

CH

AP

TE

R 6

, SIT

E 11

22

: TU

RB

IDIT

ES W

ITH

A C

ON

TO

UR

ITE F

OU

ND

AT

ION

60

Figure sponsible for major sedimentinput.

0

200

400

600

Dep

th (

mbs

f)

turb

idite

s

Lithology

lithi

f.

sed.

cont

ourit

esco

ntou

rites

F19. Provenance of diatoms in the Neogene of Hole 1122C and implications for a major change in processes re

Ple

isto

cen

e

Bru

nhes

AgeSedimentation

rates

Jar.

Old.Mat

uyam

a

high

38 cm/k.y.

Plio

c.

Gauss

Mio

cen

e

10 cm/k.y.

Provenance of diatoms

Bounty Trough

+

autochthonous

reworked

Pliocene, Miocene,

diatoms

coastal areas

pelagic plankton

mostly

Antarctic/Subantarctic

diatoms

Paleogene diatoms

B R F C D

Zeoliteabundance

xxx

xxxx

5-10 cm/k.y.~

1122C

lithifiedsediment

Antarctic/Subantarctic

AA

BW

-flo

w

Processesresponsible

do

wn

slo

pe

tran

spo

rt f

rom

Bo

un

ty T

rou

gh

are

a

?

allochthonous and

Paleogene

reworked

? in

crea

sed

uplif

t of S

outh

Isla

nd N

Z

Chrons


Figure F20. Whole-core magnetic susceptibility from Hole 1122C from the Bartington loop of the ship-board automated multisensor track, archive-half continuous measurements of NRM intensity, and intensi-ty of remanence after 20 mT of demagnetization from the pass-though cryogenic magnetometer. Verticaland subvertical lines in the lower 500 mbsf of the hole indicate intervals of nonrecovery of core.

0 0.2 0.4

Intensity (A/m) - NRM

0 0.1 0.2Intensity (A/m) - 20 mT

0 0.001 0.002

0

100

200

300

400

500

600

Susceptibility (SI)

Dep

th (

mbs

f)


Figure F21. Whole-core inclination of Hole 1122C after alternating-field demagnetization to 20 mT on thepass-though cryogenic magnetometer. Polarity interpretation is given on the right. Black (white) shadedintervals indicate normal (reversed) polarity and hatched shading indicates intervals where polarity couldnot be determined because of poor recovery. Chrons are identified from correlation with the GPTS (Candeand Kent, 1995; Berggren et al., 1995) constrained by biostratigraphy (see discussion in “Biostratigraphy,”p. 13, and Fig. F25, p. 66).

309

325 326327331339

342

400412

439 442445 451

454458

494496

519522

C5Br

C5r.2rC5r.2n

C5r.1n

C2n

C1r.1r

C2r.1r

Bru

nh

es

Matu

yam

a

Gauss

C5

C5B

PL

EIS

TO

CE

NE

PLIO

.M

IOC

EN

E

JaramilloCobb Mtn.

Olduvai

0.780.78

0.991.071.19

1.771.95

2.15~ 3

9.93

11.08

~ 15-16

Age

(M

a)

Epo

ch

Chr

ons

Pol

arity

Dep

th(m

bsf)

?

?

?

HOLE 1122C

Ash

ho

rizon

s

(12 mbsf)

(137 mbsf)

(317 mbsf)(328 mbsf)

(390 mbsf)

(454 mbsf)(457 mbsf)

Vrica ?C1r.2r

Reunion

-80 -40 0 40 80

0

100

200

300

400

500

600

Inclination (° at 20 mT)

Dep

th (

mbs

f)


Figure F22. A–I. Vector component diagrams of AF demagnetization behavior of representative discretesamples from Hole 1122C. A, B, G, I show a reversed field drilling-induced overprint on normal polaritysamples. B, C show radial remagnetization from attempts to demagnetize samples with AF fields above 50mT.

37.16 mbsf (Jmax = 1.23x10-2 A/m)

Inclination

0 AF field (mT) 60

1

J/J

max

N,Up

E,H

49.60 mbsf (Jmax = 3.17x10-2 A/m)

J/J

max

0 AF field (mT) 80

1

N,Up

E,H

Inclination

J/J max

0 AF field (mT) 80

1

J/J

max

N,Up

E,H

Inclination

J/J max

0 AF field (mT) 70

1

J/J

max

N,Up

E,H

Inclination

0 AF field (mT) 80

1

J/J

max

N,Up

E,H

Inclination

0 AF field (mT) 80

1

J/J

max

N,Up

E,H

Inclination

0 AF field (mT) 60

1

J/J

max

N,Up

E,H

Inclination

0 AF field (mT) 60

1

J/J

max

N,Up

E,H

Inclination

0 AF field (mT) 80

1

J/J

max

N,Up

E,H

Inclination

129.00 mbsf (NRM = 3.17x10-2 A/m)

235.24 mbsf (Jmax = 3.17x10-2 A/m) 272.49 mbsf (Jmax = 1.14 x10-2 A/m) 321.75 mbsf (NRM = 2.55x10-3 A/m)

369.38 mbsf (Jmax = 2.83x10-3 A/m) 419.94 mbsf (NRM = 6.54x10-3 A/m) 561.89 mbsf (Jmax = 8.69x10-3 A/m)

A B C

D E F

G H I


Figure F23. Isothermal remanent magnetization (IRM) and backfield acquisition curves for representativediscrete samples from Hole 1122C. A. Samples from above 250 mbsf, remanence saturates by 300 mT, andBcr is between 50 and 75 mT. B. Samples from 300–400 mbsf, remanence saturates by 300 mT, and Bcr is <50mT. C. Samples from beneath 400 mbsf, remanence does not saturate until nearly 1000 mT for samplesfrom 483 and 457 mbsf, Bcr values vary between 25 and 75 mT. Remanence does not become saturated until200–500 mT and Bcr is <50 mT for all samples.

-1000 -500 0 500 1000

-1

-0.5

0

0.5

1

J/Jm

ax

129.00138.82159.71185.61217.24

A

Depth (mbsf)

-1000 -500 0 500 1000

-1

-0.5

0

0.5

1

J/Jm

ax

330.62330.66339.54339.59398.38

B

Depth (mbsf)

-1000 -500 0 500 1000

-1

-0.5

0

0.5

1

Applied Field (mT)

J/Jm

ax

446.81457.67483.98513.62562.39598.61

C

Depth (mbsf)


Figure F24. A-F. Plots of normalized intensity of magnetization with progressive AF and thermal demagne-tization of saturation isothermal remanent magnetization (SIRM) for selected samples from Hole 1122C.

0

Temperature (oC)

500

J/J

max

100 200 300 400

Field strength (mT)

8070605040302010

159.71 mbsf, SIRM = 3.3 A/m

0

Temperature (oC)

500100 200 300 400 600

J/J

max

Field strength (mT)

8070605040302010

185.61 mbsf, SIRM = 5.8 A/m

0 500100 200 300 400 600

Temperature (oC)

Field strength (mT)

8070605040302010

J/J

max

217.24 mbsf, SIRM = 4.5x10-1 A/m

0

Temperature (oC)

500100 200 300 400

Field strength (mT)

8070605040302010

J/J

max

457.67 mbsf, SIRM = 1.6x10-1 A/m

0 500100 200 300 400 600

Temperature (oC)

Field strength (mT)

8070605040302010

J/J

max

513.62 mbsf, SIRM = 3.3 A/m

0 500100 200 300 400 600

Temperature (oC)

Field strength (mT)

8070605040302010

J/J

max

598.61 mbsf, SIRM = 2.6 A/m

A B C

D E F


Figure F25. Age model and correlation of Hole 1122C magnetic polarity zonation with the GeomagneticPolarity Time Scale of Berggren et al. (1995) and Cande and Kent (1995). Where correlation is unambigu-ous, it is shown by a solid black line. Black (white) shaded intervals indicate normal (reversed) polarity andhatched shading indicates intervals where polarity could not be determined because of nonrecovery. Stip-pled lines show constraining biostratigraphic datums and shaded lines show magnetic polarity correla-tions. Undulating lines indicate stratigraphic disconformities and shaded areas indicate levels of uncertain-ty in datums. Correlation is constrained by the following foraminifer, nannofossil, diatom, and radiolariandatums (see discussion in “Biostratigraphy,” p. 13; see also “Biostratigraphy,” p. 10, in the “ExplanatoryNotes” chapter). Foraminifers: F1 (FO of Gr. hirsuta, 0.45 Ma), F2 (LO of Gr. puncticuloides, 0.7–0.8 Ma), F3(several forms younger than ~3.4 Ma, see “Biostratigraphy,” p. 13), F4 (occurrence of N. continuosa and N.pachyderma, ~11.3 Ma), F5 (LO of Gr. praemenardii, ~13.0 Ma), F6 (co-occurrence of Gr. zealandica and Gr.miozea, 16.3–16.7 Ma). Nannofossils: N1 (FO of Emiliania huxleyi, 0.24 Ma), N2 (LO of Pseudoemiliania la-cunosa, 0.42 Ma), N3 (LO of R. asanoi, 0.83 Ma), N4 (FO of G. parallela, 0.9 Ma), N5 (FO of R. asanoi, 1.06Ma), N6 and N7 (range of Gephyrocapsa [large], 1.1–1.36 m.y.), N8 (FO of Gephyrocapsa [medium], 1.66 Ma),N9 (several forms co-occurring, ~3.45 Ma, see “Biostratigraphy,” p. 13), N10 (LO of C. miopelagicus, > 10.4Ma), N11 (FO of C. macintyrei, 12.34 Ma), N12 (LO of S. heteromorphus, 13.52 Ma), N13 (absence of C. prem-acintyrei FO, <17.4 Ma). Diatoms: D1 (LO of Hemidiscus karstenii, 0.18–0.19 Ma), D2 (H. karstenii, acme, 0.92Ma), D3 (LO of A ingens, 0.64 Ma), D4 (LO of T. elliptipora, 0.65–0.7 Ma), D5 (LO of Nitzschia denticuloides,11.3–22.7 Ma), D6 (LO of D. dimorpha, 12.2 Ma), D7 (FO of S. barboi, 12.5 Ma). Radiolarians: R1 (LO of Sty-latractus universus, 0.46 Ma), R2 (LO of L. nautiloides, 1.93 Ma), R3 (FO of E. calvertense, 1.92 Ma). (Figureshown on next page.)


Figure F25 (continued).

N13

F6

0 1 2 3 11 12 13 14 15 16

0

100

200

300

400

500

600

N1

F1

N2

R1

D3

D4

N6

F3 N9

D6

F4

D7 N12

D1

N5

N4

F2

N7

N8

R2

D2

N3

N10D5

N11

R3

Sed. Rate= ~ 400 m/m.y.


Brunhes Matuyama GaussPleistocene Pliocene middle Miocene

C5BrC5rC5n

C5A

n

C5A

r

C5

AB

n

C5A

Cn

C5A

Dn

C5B

n

C5r

.1n

C5r.

2n

Jara

mill

o

Old

uv.

Reu

nion


F5

G P T S

Po

lari

ty

Dep

th (

mbs

f)Age (Ma)

Hole1122C

Ash

Ash

AshAsh

Ash

Ashes


Figure F26. Composite sections for MS, GRAPE, and reflectance percentage at 550 nm. For convenience, MSvalues from Holes 1122B, 1122C, and Core 181-1122C-3H are offset by 70 × 10–5, 140 × 10–5, and 240 × 10–5,respectively; GRAPE values are offset by 0.4, 0.8, and 1.2 g/cm3, respectively; and reflectance values are offsetby 8%, 16%, and 22%, respectively. Gaps in the composite section are indicated with triangles. Cores are in-dicated by small numbers. KK indicates the approximate depth of the Kawakawa Tephra (12.62 mcd in Core181-1122A-1H, 13.14 mcd in Core 2H, and 12.74 mcd in Core 3H). (Continued on next page.)

0 200 400

40

30

20

10

0

Dep

th (

mcd

)

Magnetic Susceptibility

(x10-5 SI)

A

B C

1

2

3

4

1

1

2

3

4

5

6

KK

1.5 2 2.5 3

40

30

20

10

0

SITE 1122

GRAPE density

(g/cm3)

1

2

3

4

1

1

2

3

4

5

6

0 20 40

40

30

20

10

0

Reflectance Percentage

(550 nm, smoothed)

1

2

3

4

1

1

2

3

4

5

6


Figure F26 (continued).

0 200 400

80

70

60

50

Dep

th (

mcd

)

Magnetic Susceptibility

(x10-5 SI)

A C

4

5

6

7

8

6

7

8

9

10

gap

1.5 2 2.5

80

70

60

50

SITE 1122

GRAPE density

(g/cm3)

4

5

6

7

8

6

7

8

9

10

gap

0 20 40

80

70

60

50

Reflectance Percentage

(550 nm, smoothed)

4

5

6

7

8

6

7

8

9

10

gap


Figure F27. Downhole depth offsets between the mbsf and mcd scales for Site 1122. Solid line indicates thetrend for a typical 10% stretch model between mbsf and mcd depths. Composite depth offsets are unusu-ally constant downhole and do not follow a stretch model.

0 5 10 15

Offset (m)

Dep

th (

mbs

f)

Hole 1122A

Hole 1122B

Hole 1122C100

80

60

40

20

0

6. site 1122: turbidites with a contourite foundation€¦ · shipboard scientific party chapter 6,...

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