Calcareous Nannofossil Biostratigraphy of XY-1 Field,Offshore Western Niger Delta, Nigeria

International Journal of Science and Technology Volume 3 No. 5, May, 2014

IJST © 2014– IJST Publications UK. All rights reserved. 285

Calcareous Nannofossil Biostratigraphy of XY-1 Field,Offshore Western

Niger Delta, Nigeria

S. O. Obaje1, E. A. Okosun2, P. I. Olasehinde2 & E. E. Udensi3

1Nigerian Geological Survey Agency, P.M.B. 1423, Fate, Ilorin, Kwara State, Nigeria 2Department of Geology, Federal University of Technology, P.M.B. 65, Minna, Nigeria. 3Department of Physics, Federal University of Technology, P.M.B. 65, Minna, Nigeria.

ABSTRACT

The scope and objectives of the research study involved the following: the identification of calcareous nannofossils and their abundance

in the strata penetrated in the wells, calcareous nannofossil biozonation of the wells intervals, determination of the ages of the studied

well depth intervals and the correlation of the five wells in the study area. The area of study is located in the offshore XY-1 Field of

the offshore western Niger Delta area of Nigeria. Niger Delta lies between latitudes 4° and 6° N and longitudes 3° and 9° E in the

south-south geo-political region of Nigeria. A total of 1,100 ditch cutting samples were collected from five wells at the industry

standard of 9.14 m depth intervals. The pipette and smear laboratory technique was used for the calcareous nannofossils preparation.

The identified calcareous nannofossil assemblages were used for biostratigraphic interpretation. Three calcareous nannofossil biozones

were identified and they are Calcidiscus premacintyrei (Zone NN6-NN7), Catinaster coalitus (Zone NN8) and Discoaster hamatus

(Zone NN9). The biozones were used for the correlation of the five wells. These biozones are indicative of Middle to Late Miocene

age for the well depth intervals. The biostratigraphic interpretation of these wells is useful for mapping subsurface horizons in the

offshore western Niger Delta area of Nigeria.

Keywords: Calcareous nannofossils, biostratigraphy, XY-1 Field, offshore western Niger Delta, Nigeria

1. INTRODUCTION

The study area is located in the offshore western Niger Delta

area, Nigeria (Figure 1). The Niger Delta is situated in the Gulf

of Guinea on the west coast of Central Africa. It lies between

latitudes 4° and 6° N and longitudes 3° and 9° E in southern

Nigeria [9]. The Delta is situated at the intersection of the

Benue Trough and the South Atlantic Ocean where a triple

junction developed during the separation of South America and

Africa in the Late Jurassic [13].

The aim of the research was to identify and analyze the

abundance of calcareous nannofossils in the strata penetrated

by the studied wells and to use the data to zone, date, and

correlate the wells.

2. GEOLOGICAL SETTING

Three formations have been recognized in the subsurface of the

onshore and offshore Niger Delta [6], [10], [12], [1], [7], [11].

These are the Akata, Agbada and Benin Formations. These

formations were deposited in marine, transitional and

continental environments, respectively; together they form a

thick, overall progradational passive-margin wedge [5]. The

Akata Formation, the basal unit, is composed mainly of marine

shales believed to be the main source rock within the basin.

The Agbada Formation is made up of alternating sandstone,

siltstone and shale sequences that constitute the petroleum

reservoirs of the basin and it is Eocene to Pliocene in age. The

topmost unit called the Benin Formation largely consists of

non-marine sands with shaly intercalations [5].

3. METHODS OF STUDY

3.1 Calcareous Nannofossils: Pipette and

Smear Method

The five wells are denoted by TMB- 1, 2, 4, 5 & 6 and they

have 226, 212, 222, 216 and 224 ditch cutting samples,

respectively, totalling 1,100 samples that were collected at the

International Journal of Science and Technology (IJST) – Volume 3 No. 5, May, 2014


industry standard of 9.14 m sampling intervals for analysis for

calcareous nannofossils. The pipette and smear technique was

used for calcareous nannofossils preparation. The unwashed

ditch cuttings were slightly rinsed to remove drilling mud.

Absolute care was taken at all stages of the sample preparation

to avoid contamination. About 25 grams of each sample were

required but 10 grams were utilized. They were broken down

by soaking and swirling in distilled water. Addition of a small

quantity of sodium hexametaphoshate (calgon) helped in the

dispersion of the clays and ensured even distribution of the

particles in the final mount. Drops of the suspensions taken

from the beakers using pipette were carefully placed on glass

cover slips (22 mm x 22 mm). Few drops of distilled water

were added to dilute the suspensions, which were then dried on

a hot plate. Two blobs of Norland optical adhesive (Refractive

Index = 1.56) were placed on glass slips with the samples

inverted over the glass slides until the adhesive was completely

spread evenly, resulting in clean mounts. The mounts were

cured over ultraviolet light for 30-45 minutes. The glass slides

were then made ready for inspection under the microscope.

The statistical data were recorded using the StrataBugs

software. The complete nannopaleontological data were

plotted in colour using the StrataBugs software at 1:5,000 scale

with depth in Y-axis and the identified taxa in X-axis for each

well. The StrataBugs software plotted charts were interpreted

using the first and last downhole occurrences of diagnostic

taxa, the assemblages, ratio of taxa occurrence, and taxon

quantitative distribution within the stratigraphic interval.

4. RESULTS AND DISCUSSION

4.1 Calcareous Nannofossil Biozones

Twenty-six species of calcareous nannofossil assemblages

were found at different depths in the five wells studied. The

first occurrences (referred to as the last downhole occurrences)

and the last occurrences (referred to as the first downhole

occurrences) of selected marker species were used to delineate

the biozones. In this study, the standard nannoplankton

zonation scheme of Martini [8] was utilized. Martini [8] used

Nannoplankton Neogene (NN) and numbers to identify zones.

In the five wells studied, three biozones were recognized and

they are equivalent to NN6-NN7, NN8 and NN9 Zones of

Martini [8]. The calcareous nannofossil biozones recognized

indicated Middle to Late Miocene age (Figures 2-7).

Photomicrographs of marker species used for the biozones are

shown in Figure 8.

4.1.1 Calcidiscus premacintyrei Zone

Stratigraphic interval:

TMB -1 Well: 3,150.41-3,446.37 m

TMB -2 Well: 3,218.08-3,404.92 m

TMB -4 Well: -

TMB -5 Well: 2,933.10-3,466.80 m

TMB -6 Well: 3,622.55-3,907.23 m

Base: The base of this zone is defined by the first downhole

occurrence of Calcidiscus premacintyrei (THEODORIDIS) at

the depths of 3,446.37 m, 3,404.92 m, 3,466.80 m and 3,907.23

m in TMB- 1, 2, 5 and 6 wells, respectively. The base of this

zone is dated to 12.8 Ma of Berggren et al. [2].

Top: The top of this zone is defined by the last downhole

occurrence of Catinaster coalitus (MARTINI &

BRAMLETTE) at depths of 3,150.41 m, 3,218.08 m, 2,933.10

m and 3,622.55 m in TMB- 1, 2, 5 and 6 wells, respectively.

The associated fossil species are Cyclocargolithus floridanus

(ROTH & HAY), D. bolli (MARTINI & BRAMLETTE), D.

braarudii (BUKRY), S. heteromorphus (DEFLANDRE) and

D. exilis (MARTINI & BRAMLETTE).

Age: Middle - Late Miocene equivalent to NN6-NN7 Zones of

Martini [8].

4.1.2 Catinaster coalitus Zone


TMB -1 Well: 2,731.31-3,150.41 m

TMB -2 Well: 2,882.80-3,218.08 m

TMB -4 Well: -

TMB -5 Well: 2,443.89-2,933.10 m

TMB -6 Well: 3,258.01-3,622.55 m

Base: The base of this zone is defined by the last downhole

occurrence of Catinaster coalitus (MARTINI &


m and 3,622.55 m in TMB - 1, 2, 5 and 6 wells, respectively.

Top: The top of this zone is defined by the last downhole

occurrence of Discoaster hamatus (MARTINI &


m and 3,258.01 m in TMB- 1, 2, 5 and 6, respectively. The top

of this zone is dated to 10.4 Ma of Berggren et al. [2]. The

associated species within this zone are D. bellus (BUKRY &

PERCIVAL), D. exilis (MARTINI & BRAMLETTE),

Catinaster calyculus (MARTINI & BRAMLETTE), D. bolli

(MARTINI & BRAMLETTE), D. braarudii (BUKRY) and R.

haqii (BACKMAN), etc.

Age: Late Miocene equivalent to NN8 Zone of Martini [8].

4.1.3 Discoaster hamatus Zone


TMB -1 Well: 2,431.39-2,731.31 m

TMB -2 Well: 2,431.39-2,882.80 m

TMB -4 Well: -

TMB -5 Well: -

TMB -6 Well: -

Base: The base of this zone is defined by the last downhole


BRAMLETTE) at depths of 2,731.31 m and 2,882.80 m in

TMB-1 and 2 wells. Though the entire zone is absent in TMB-

4, 5 and 6 wells, however, the base of this zone was identified

at depths of 2,443.89 m and 3,258.01 m in TMB- 5 and 6 wells.

The base of this zone marked the end of NN8 Zone of Martini

[8] and it is dated to 10.4 Ma of Berggren et al. [2].

Top: The top of this zone is defined by the first downhole


BRAMLETTE) at depths of 2,431.39 m in TMB- 1 and 2

wells. However, the top of this zone was not recognized in

TMB- 5 and 6 wells. The associated species are

Reticulofenestra pseudoumbilicus (> 7 µm) (GARTNER),

Coccolithus pelagicus (WALLICH), Calcidiscus leptoporous

(MURRAY & BLACKMAN), D. bolli (MARTINI &

BRAMLETTE), D. braarudii (BUKRY) and D. bellus

(BUKRY & PERCIVAL) [3], [14].



Age: Late Miocene and equivalent to the Discoaster hamatus

(NN9) Zone of Martini [8].

Remarks: The diagnostic species for this zone is Discoaster

hamatus (MARTINI & BRAMLETTE).

4.2 Correlation of XY-1 Field

4.2.1 Calcareous Nannofossil Biozones

Correlation

Three biozones, namely: Calcidiscus premacintyrei (Zone

NN6-NN7), Catinaster coalitus (Zone NN8) and Discoaster

hamatus (Zone NN9) were identified and correlated in TMB-1

and TMB-2 wells, respectively. Calcidiscus premacintyrei

(Zone NN6-NN7) was found between intervals of 3,150.42 m

to 3,446.37 m in TMB-1 well and 3,218.08 m to 3,404.92 m in

TMB-2 well, 2,933.10 m to 3,466.80 m in TMB-5 well and

3,622.55 m to 3,907.23 m in TMB-6 well. But it was

completely absent in TMB-4, probably because it was eroded

away thereby erasing the record from the well. Also,

Catinaster coalitus (Zone NN8) was found between intervals

of 2,731.31 m to 3,150 m in TMB-1 well, 2,443.89 m to

2,933.10 m in TMB-5 well, 3,258.01 m to 3,622.55 m in TMB-

6 well. Alternatively, Discoaster hamatus (Zone NN9) was

found between intervals of 2,431.39 m to 2,731.31 m in TMB-

1 well, 2,431.39 m to 2,882.80 m in TMB-2 well and 3,258.01

m to 3,622.55 m in TMB-6 well. However, it was absent in

TMB-4 and TMB-5 wells (Figure 7). It may be inferred from

the biozone correlation of the wells that TMB-1 and TMB-2

wells have complete set of the biozones because they were

preserved from erosion and denudational forces. On the other

hand, between TMB-2 and TMB-4 wells, strong evidence of

eroded horizons probably due to uplifting, faulting and erosion

was inferred as possible source of the observed unconformity.

Similar scenario was noticed between TMB-4 well and TMB-

5 well. From the correlation, there are faults between TMB-4,

5 and 6 wells, respectively. Between TMB-4 and TMB-5, the

downthrown side of the fault was inferred in the TMB-4 well

area, alternatively between TMB-5 and 6 wells, respectively,

the downthrown side was deduced in the TMB-6 well area

(Figure 7). The significance of the biozones cannot be

overemphasized because of their usefulness in subsurface

mapping and reservoir characterization study, especially in

tectonically complex areas.

5. CONCLUSION

The study aim and objectives were achieved. The biozones and

correlation give better understanding of the geology of the area

useful for regional subsurface geological mapping and the

development of the offshore western Niger Delta serving as

good input into the reservoir characterization model. The

calcareous nannofossil biozones defined indicated various

stratigraphic variations in some taxa in the studied wells in

comparison to standard biozonation scheme [8], [2], [15]. The

three calcareous nannofossil biozones that were identified are

Calcidiscus premacintyrei (Zone NN6-NN7), Catinaster

coalitus (Zone NN8) and Discoaster hamatus (Zone NN9).

These biozones are indicative of Middle to Late Miocene age

for the well depth intervals.

Depth

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

11500'

11750'

12000'

12250'

Gamma Log(API)0 150

Inte

rpre

ted

litho

logy

Deep Laterolog(ohm m/m)0.2 2000

Chr

onos

trat

igra

phy

5010

Late

Mio

cene

8930

12440

Mid

dle

Mio

cene

Age

Samples

Barr

en

50305060509051205150518052105240527053005330536053905420545054805510554055705600563056605690572057505780581058405870590059305960599060206050608061106140617062006230626063206350638064106440647065006530656065906620665066806710674067706800683068606890692069506980704071007130716071907220725073107340737074007430744474907520755075807610764076707700773077607790782078507880791079407970797880008030806080908120815081808210824082708300833083608390842084508480851085408570863086608661869087208750878088108840887089008930896089628990902090509080911091409170920092309260929093209380941094409470950095309560959096209650968097109740977098009830986098909920995099801001010040100701010010130101601019010220102501028010310103361034010370104001043010460104901052010550105801061010640106701070010730107601082010850108801091010940109701100011030110601109011120111501118011210112401127011300113081133011360113901142011450114801151011540115701160011630116601169011720117501178011810118401187011900119301196011990120201205012080121101214012170122001223012260122901232012350123801241012440

Semi-quantitative, (Default Abundance Scheme)

In-Situ occurrences

Cal

cidi

scus

lept

opor

ous

Sph

enol

ithus

mor

iform

is

Dis

coas

ter e

xilis

Ret

icul

ofen

estra

pse

udou

mbi

licus

(5-7

mic

rons

)

Cat

inas

ter c

alyc

ulus

Dis

coas

ter b

ellu

s

Dis

coas

ter q

uinq

uera

mus

Hel

icos

phae

ra c

arte

ri

Ret

icul

ofen

estra

pse

udou

mbi

licus

(>7m

icro

ns)

Um

bilic

osph

aera

rotu

la

Cal

cidi

scus

pre

mac

inty

rei

Coc

colit

hus

pela

gicu

s

Cat

inas

ter c

oalit

hus

Hel

icos

phae

ra s

talis

Pon

tosp

haer

a ja

poni

ca

Sph

enol

ithus

het

erom

orph

us

Dis

coas

ter b

raar

udii

Dis

coas

ter s

p (fr

agm

ents

)

Cyc

licar

golit

hus

florid

anus

Nannofossil

Div

ersi

ty: N

anno

pala

eont

olog

y

80

In-S

itu o

ccur

renc

es

2

1

1

1

9

1

2

5

1

8

1

1

1

2

2

2

4

1

1

1

5

1

3

4

1

Nanno.

Tota

l cou

nt: N

anno

pala

eont

olog

y

150

In-S

itu o

ccur

renc

es

2

1

1

1

24

1

2

7

1

11

1

3

1

2

2

2

91

1

1

7

1

3

9

1

Nanno.

Well Name : TOMBOY-1Operator : OBAJE SOLOMON

Well Code : TOMBOY-1

Interval : 5010' - 12440'

Scale : 1:5000

Chart date: 07 August 2008 Project

Chart

: BIOSTRAT

: TOM-1NANNO

8930.00' CU : Acme: Discoaster bollii, Discoasterhamatus (10.4Ma)

BIOEVENTS Depth

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

11500'

11750'

12000'

12250'

Base Lithology

clay

shale/mudstone

silty mudstone

siltstone

argillaceous siltstone

sandy siltstone

sandstone (fine - medium)

argillaceous sandstone

mixed sandstone (70% coarse)

BIOZONATION AND CORRELATION OF XY-1 FIELD, OFFSHORE WESTERN NIGER DELTA, NIGERIA

Well Name: TMB-1

Interval: 5010’-12440’

Scale: 1:5000

Chart Date: 06 August,

2008

11307’ CU: 12.8 Ma

FDO: CALCIDISCUS

PREMACINTYREI

10336’ CU: 11.5 Ma

LDO: CATINASTER

COALITUS

8961’ CU: 10.4 Ma

LDO: DISCOASTER

HAMATUS

7977’ CU: 9.5 Ma

FDO: DISCOASTER

HAMATUS

DIS

COA

STER

HA

MA

TUS

CATI

NA

STER

CO

ALI

TUS

CALC

IDIS

CUS

PRE

MA

CIN

TYRE

I

THIS STUDY

BIOEVENTS

NN6

NN7

NN8

NN9

MID

DLE

MIO

CEN

ELA

TE M

IOCE

NE

> 15 specimens

> 5 “

< 5 “

MA

RTI

NI (

1971

)

Figure 2: Calcareous Nannofossils Stratigraphic Chart of TMB-1 Well



Depth

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

11500'

11750'

12000'

12250'

Gamma Log(API)0 150

Litho

logy

Deep Induction(ohm m/m)0.2 2000

Chro

nostr

atigr

aphy

5010

Late

Mioc

ene

10310

12440

Midd

le Mi

ocen

eAg

e

Samples

Barre

n

503050605090512051505180521052405270530053305360539054205450548055105540557056005630566056905720575057805810584058705900593059605990602060506080611061406170620062306260632063506380641064406470650065306560659066206650668067106740677068006830686068906920695069807040710071307160719072207250731073407370740074307490752075507580761076407670770077307760779078207850788079107940797079788000803080608090812081508180821082408270830083308360839084208450848085108540857086308660869087208750878088108840887089008930896089909020905090809110914091709200923092609290932093809410944094599470950095309560959096209650968097109740977098009830986098909920995099801001010040100701010010130101601019010220102501028010310103401037010400104301046010490105201055010559105801061010640106701070010730107601082010850108801091010940109701100011030110601109011120111501117111180112101124011270113001133011360113901142011450114801151011540115701160011630116601169011720117501178011810118401187011900119301196011990120201205012080121101214012170122001223012260122901232012350123801241012440


In-Situ occurrences

Calci

discu

s lep

toporo

us

Catin

aster

calyc

ulus

Disc

oaste

r bell

us

Disc

oaste

r quin

quera

mus

Helic

osph

aera

carte

ri

Retic

ulofen

estra

pseu

doum

bilicu

s (5-7

micro

ns)

Retic

ulofen

estra

pseu

doum

bilicu

s(>7m

icron

s)

Sphe

nolith

us m

orifor

mis

Umbil

icosp

haera

rotul

a

Calci

discu

s prem

acint

yrei

Cocc

olithu

s pela

gicus

Catin

aster

coali

thus

Helic

osph

aera

stalis

Ponto

spha

era ja

ponic

a

Sphe

nolith

us he

terom

orphu

s

Disc

oaste

r braa

rudii

Disc

oaste

r sp (

fragm

ents)

Cycli

cargo

lithus

florid

anus

Nannofossil

Dive

rsity:

Nan

nopa

laeon

tolog

y

50

In-Sit

u occ

urren

ces

9

1

2

5

1

1

1

1

2

8

2

2

41

1

1

1

5

3

4

1

Nanno.

Total

coun

t: Nan

nopa

laeon

tolog

y

100

In-Sit

u occ

urren

ces

43

1

2

7

1

1

3

1

2

21

2

2

91

1

1

1

7

3

18

1

Nanno.

BIOEVENTS Depth

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

11500'

11750'

12000'

12250'



Lat/Long : 52°31' 25.01"N 2° 2' 3.00"E

Interval : 5010' - 12440'

Scale : 1:5000

TOMBOY-2Chart date: 07 August 2008 Project

Chart

: BIOSTRAT

: TOMBOY-2 NANNO

Base Lithology

shale/mudstone

silty mudstone

siltstone


sandy siltstone




IGD Boundary KeyPossible

Probable

Confident

Unconformable

? ?Unconformable

f Fault

?f ?Fault

> 15 specimens

> 5 “

< 5 “

BIOZONATION AND CORRELATION OF XY-1 FIELD, OFFSHORE WESTERN NIGER DELTA, NIGERIA Well Name: TMB-2

Interval: 5010’-12440’

Scale: 1:5000

Chart Date: 06 August, 2008

BIOEVENTS

10558’ CU: 11.5 Ma

LDO: CATINASTER

COALITUS

9458’ CU: 10.4 Ma

LDO: DISCOASTER

HAMATUS

7977’ CU: 9.5 Ma

FDO: DISCOASTER

HAMATUS

DIS

CO

AST

ER H

AM

ATU

SC

ATI

NA

STER

CO

ALI

TUS

CA

LCID

ISC

US

P

REM

AC

INTY

REI

THIS STUDY

MA

RTI

NI (

19

71

)

NN6

NN7

NN8

NN9

11171’ CU: 12.8 Ma

FDO: CALCIDISCUS

PREMACINTYREI


Depth

2500'

2750'

3000'

3250'

3500'

3750'

4000'

4250'

4500'

4750'

5000'

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

Gamma Log(API)0 150

Interp

reted

litho

logy


Chron

ostra

tigrap

hy

2400

LATE

MIOC

ENE

7984

11460

MIDD

LE M

IOCEN

EAg

e


In-Situ occurrences

Disco

aster

exilis

Calcid

iscus

lepto

porou

s

Reticu

lofen

estra

pseu

doum

bilicu

s (5-7

micro

ns)

Catin

aster

calyc

ulus

Disco

aster

bellu

s

Disco

aster

quinq

ueram

us

Helico

spha

era ca

rteri

Reticu

lofen

estra

pseu

doum

bilicu

s(>7m

icron

s)

Sphe

nolith

us m

orifor

mis

Umbil

icosp

haera

rotul

a

Calcid

iscus

prem

acint

yrei

Cocco

lithus

pelag

icus

Catin

aster

coali

thus

Helico

spha

era sta

lis

Ponto

spha

era ja

ponic

a

Sphe

nolith

us he

terom

orphu

s

Disco

aster

braa

rudii

Disco

aster

sp (fr

agme

nts)

Cyclic

argoli

thus fl

orida

nus

Nannofossil

Divers

ity: Na

nnop

alaeo

ntolog

y

50

In-Sit

u occu

rrenc

es

1

1

1

99

1

2

5

1

8

1

1

1

2

2

2

41

1

1

5

1

8

3

4

Nanno.

Total

coun

t: Nan

nopa

laeon

tolog

y

80

In-Sit

u occu

rrenc

es

1

1

1

2438

1

2

7

1

11

1

3

1

2

2

2

91

1

1

7

1

11

3

9

Nanno.



Interval : 2400' - 11460'

Scale : 1:5000


Chart

: BIOSTRAT

: TOM-4NANNO

BIOEVENTS Depth

2500'

2750'

3000'

3250'

3500'

3750'

4000'

4250'

4500'

4750'

5000'

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

Base Lithology

shale/mudstone

silty mudstone

sandy mudstone

siltstone





Interval: 2400’-11460’

Scale: 1:5000


> 15 specimens

> 5 “

< 5 “

NN

7-N

N9

BIOEVENTSTHIS STUDY

10561’ CU: 11.5 Ma LDO: CATINASTER

COALITUS

UN

IDE

NT

IFIE

D

ZO

NE

MA

RT

INI

(19

71

)




Depth

4000'

4250'

4500'

4750'

5000'

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

11500'

Gamma Log(API)0 150

Inter

prete

d lith

ology


Chro

nostr

atigr

aphy

4000

LATE

MIO

CENE

9623

11460

MIDD

LE M

IOCE

NEAg

e


In-Situ occurrences

Disc

oaste

r exil

is

Calci

discu

s lep

toporo

us

Retic

ulofen

estra

pseu

doum

bilicu

s (5-7

micro

ns)

Catin

aster

calyc

ulus

Disc

oaste

r bell

us

Disc

oaste

r quin

quera

mus

Helic

osph

aera

carte

ri

Retic

ulofen

estra

pseu

doum

bilicu

s(>7m

icron

s)

Sphe

nolith

us m

orifor

mis

Umbil

icosp

haera

rotul

a

Calci

discu

s prem

acint

yrei

Cocc

olithu

s pela

gicus

Catin

aster

coali

thus

Helic

osph

aera

stalis

Ponto

spha

era ja

ponic

a

Sphe

nolith

us he

terom

orphu

s

Disc

oaste

r braa

rudii

Disc

oaste

r sp (

fragm

ents)

Cycli

cargo

lithus

florid

anus

Nannofossil

Dive

rsity:

Nan

nopa

laeon

tolog

y

8

In-Sit

u occ

urren

ces

1

11

9

9

1

25

1

8

1

1

1

2

22

41

81

1

5

1

3

4

5

Nanno.

Total

coun

t: Nan

nopa

laeon

tolog

y

20

In-Sit

u occ

urren

ces

1

1

1

24

50

1

27

1

11

1

3

1

2

22

91

321

1

7

1

3

9

7

Nanno.



Interval : 4000' - 11600'

Scale : 1:5000


Chart

: BIOSTRAT

: TOM-5 NANNO

7933.14' CU : ? 10.35 Ma SB

8018.21' CU : ? 10.4 Ma MFS

9547.08' CU : ? 10.6 Ma SB

9623.36' CU : ? 11.5 Ma MFS

11113.91' CU : ? 12.1 Ma SB

11374.51' CU : ? 12.8 Ma MFS

Comments Depth

4000'

4250'

4500'

4750'

5000'

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

11500'

Base Lithology

shale/mudstone

silty mudstone

siltstone


sandy siltstone




Interval: 4000’-11600’

Scale: 1:5000


11374’ CU: 12.8 Ma FDO: CALCIDISCUS PREMACINTYREI

9623’ CU: 11.5 Ma LDO: CATINASTER COALITUS

8018’ CU: 10.4 Ma LDO: DISCOASTER HAMATUS

CA

TIN

AST

ER C

OA

LITU

SC

ALC

IDIS

CU

S P

REM

AC

INTY

REI

THIS STUDY

BIOEVENTS

NN6

NN7

NN8

NN9

MA

RTI

NI (

19

71

)

> 15 specimens

> 5 “

< 5 “


Depth

4000'

4250'

4500'

4750'

5000'

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

11500'

11750'

12000'

12250'

12500'

12750'

13000'

Gamma Log(API)0 150 Int

erpret

ed lit

holog

y


Chron

ostra

tigrap

hy

4000

LATE

MIOC

ENE

10689

13000

MIDDL

E MIOC

ENE

Age

Samples

Barre

n

40104040407041004130416041904220425042804310434043704400443044604490452045504580461046404670470047304760479048204850488049104940497050005030506050905120515051805210524052705300533053605390542054505480551055405570560056305660569057205750578058105840587059005930596059906020605060806110614061706200623062606320635063806410644064706500653065606590662066506680671067406770680068306860689069206950698070407100713071607190722072507310734073707400743074447490752075507580761076407670770077307760779078207850788079107940797079788000803080608090812081508180821082408270830083308360839084208450848085108540857086308660866186908720875087808810884088708900893089608962899090209050908091109140917092009230926092909320938094109440947095009530956095909620965096809710974097709800983098609890992099509980100101004010070101001013010160101901022010250102801031010336103401037010400104301046010490105201055010580106101064010670106891070010730107601082010850108801091010940109701100011030110601109011120111501118011210112401127011300113081133011360113901142011450114801151011540115701160011630116601169011720117501178011810118401187011885119001193011960

12819


In-Situ occurrences

Discoa

ster e

xilis

Calcid

iscus

leptop

orous

Reticu

lofene

stra ps

eudo

umbili

cus (5

-7micro

ns)

Catina

ster ca

lyculu

s

Discoa

ster b

ellus

Discoa

ster q

uinqu

eramu

s

Helico

sphae

ra car

teri

Reticu

lofene

stra ps

eudo

umbili

cus(>7

micron

s)

Sphe

nolith

us mo

riform

is

Umbili

cosph

aera

rotula

Calcid

iscus

prema

cintyre

i

Cocco

lithus

pelag

icus

Catina

ster co

alithu

s

Helico

sphae

ra sta

lis

Ponto

sphae

ra jap

onica

Sphe

nolith

us he

terom

orphu

s

Discoa

ster b

raarud

ii

Discoa

ster sp

(frag

ments

)

Cyclic

argolit

hus fl

orida

nus

Nannofossil

Divers

ity: Na

nnop

alaeo

ntolog

y

10

In-Sit

u occu

rrence

s

1

11

9

1

25

1

8

1

1

1

2

22

41

1

1

5

1

9

3

4

1

8

5

Nanno.

Total

count:

Nann

opala

eonto

logy

10

In-Sit

u occu

rrence

s

1

11

24

1

27

1

11

1

3

1

2

22

91

1

1

7

1

34

3

9

1

11

18

Nanno.



Interval : 4000' - 13000'

Scale : 1:5000


Chart

: BIOSTRAT

: TOM- 6 NANNO

BIOEVENTS Depth

4000'

4250'

4500'

4750'

5000'

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

11500'

11750'

12000'

12250'

12500'

12750'

13000'

Base Lithology

shale/mudstone

silty mudstone

sandy mudstone

siltstone



sandstone (coarse)


> 15 specimens

> 5 “

< 5 “

NN7

NN8

NN9

MA

RTI

NI (

19

71

)

12819’ CU: 12.8 Ma FDO: CALCIDISCUS

PREMACINTYREI

11885’ CU: 11.5 Ma LDO: CATINASTER COALITUS

10689’ CU: 10.4 Ma LDO: DISCOASTER HAMATUS}

CA

TIN

AST

ER C

OA

LITU

SC

ALC

IDIS

CU

S

PR

EMA

CIN

TYR

EI

THIS STUDY

BIOEVENTS


Interval: 4010’-13000’

Scale: 1:5000


UN

IDEN

TIFI

ED Z

ON

E




Depth

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

11500'

11750'

12000'

12250'

Gamma Log(API)0 150

Lit

ho

log

y


Lit

ho

stra

tig

rap

hy

5010

Be

nin

Fo

rma

tio

n

7444

12440

Ag

ba

da

Fo

rm

atio

nF

orm

atio

n

Se

qu

en

ce

5010

PG

C

7444

HS

T

7978

TS

T

8661

HS

T

8962

TS

T

9994

HS

T

10336

TS

T

10871

HS

T

11308

12440

TS

T

Div

ers

ity: M

icro

pa

lae

on

tolo

gy

60

In-S

itu o

ccurren

ces

5

6

4

12

16

5

9

7

7

6

10

8

12

7

15

9

5

8

13

3

4

7

4

4

15

5

8

8

26

7

2

2

1

1

1

4

252

4

1

11

5

6

7

3

4

201

2

4

3

5

28

2525

32

29

3

9

2

32

3

1

8

1

10

5

9

16

13

5

8

3

2

10

514

10

10

5

1

2

249

1

2

1

4

4

4

3

3

186

7

10

16

6

9

10

3

26

8

8

13

19

18

11

10

9

11

97

423

12

8

2

1

8

5

4

4

2

Micro.

To

tal co

un

t: M

icrop

ala

eo

nto

log

y

80

In-S

itu o

ccurren

ces

8

6

5

21

41

5

12

10

18

13

17

17

44

12

46

17

7

23

27

7

5

12

5

4

35

5

28

16

130

14

3

3

1

1

2

4

1012

12

3

30

13

11

7

3

5

1221

3

8

3

7

64

150105

117

116

3

13

2

137

4

1

11

1

18

7

19

32

28

7

13

3

8

13

524

12

32

5

1

2

14112

1

3

2

7

4

4

6

6

458

18

13

24

9

15

16

3

168

11

9

25

56

43

21

14

11

18

23104

6121

16

2

1

15

10

4

4

2

Micro. *1

*2

Non M

arin

e

Div

ers

ity: N

an

nop

ala

eo

nto

log

y

15

In-S

itu o

ccurren

ces

3

21

111

4

54

86

61

82

1

3

1

2

1

11

9

1

25

1

8

1

1

1

2

22

41

1

1

5

1

3

4

1

Nanno.

To

tal co

un

t: N

an

no

pa

lae

on

tolo

gy

10

In-S

itu o

ccurren

ces

5

21

111

5

65

98

61

112

1

4

1

2

1

11

24

1

27

1

11

1

3

1

2

22

91

1

1

7

1

3

9

1

Nanno.

Events

7444' 8.5Ma SB

7977' 9.5Ma MFS

8660' 10.35Ma SB

8961' 10.4Ma MFS

9994' 10.6Ma SB

10336' 11.5Ma MFS

10871' 12.1Ma SB

11307' 12.8Ma MFS

Depth

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

11500'

11750'

12000'

12250'

Gamma Log(API)0 150

Lit

ho

log

y


Lit

ho

stra

tig

rap

hy

5010

Be

nin

Fo

rma

tio

n

7940

12440

Ag

ba

da

Fo

rm

atio

nF

orm

atio

n

Se

qu

en

ce

5010

PG

C

HST7978

TS

T

8108

PG

C

HST

TST9543

PG

C

10358

HS

T

10559

TS

T

HST11171

TS

T

11293

12440

HS

T

Div

ers

ity: M

icro

pa

lae

on

tolo

gy

20

In-S

itu o

ccurren

ces

4

5

6

4

12

16

5

9

7

7

6

10

8

12

7

15

9

5

8

13

3

4

7

4

4

15

5

8

8

26

7

2

2

1

1

1

4

2

4

1

11

5

6

7

3

2912

1

2

4

3

5

14

6

6

11

3

9

2

3

1

8

1

2510

526

9

16

13

5

8

3

2

10

5

10

10

5

1

2

914

1

2

1

164

4

4

3

3

6

7

10

1614

626

9

10

253

8

8

13

19

18

11

10

9

11

9

8

11

6

6

6

3

6

5

Micro.

To

tal co

un

t: M

icrop

ala

eo

nto

log

y

40

In-S

itu o

ccurren

ces

4

8

6

5

21

23

5

12

10

18

13

17

17

21

12

27

17

7

23

27

7

5

12

5

4

24

5

28

16

37

14

3

3

1

1

2

4

2

12

3

30

13

11

7

3

7344

1

3

8

3

7

21

16

16

39

3

13

2

4

1

11

1

6518

7130

19

32

28

7

13

3

8

13

5

12

32

5

1

2

1224

1

3

2

327

4

4

6

6

8

18

13

2417

997

15

16

563

11

9

25

56

43

21

14

11

18

23

8

17

7

11

11

5

10

9

Micro. Palaeoenvironment

Default

Non M

arin

e

Transitio

nal

Inner

Neritic

Mid

dle

N

eritic

Div

ers

ity: N

an

nop

ala

eo

nto

log

y

8

In-S

itu o

ccurren

ces

3

21

111

4

74

89

61

82

1

3

12

1

11

9

1

25

1

1

1

1

2

8

22

41

1

1

1

5

3

4

1

Nanno.

To

tal co

un

t: N

an

no

pa

lae

on

tolo

gy

15

In-S

itu o

ccurren

ces

5

21

111

10

127

1924

91

112

1

4

12

1

11

43

1

27

1

1

3

1

2

21

22

91

1

1

1

7

3

18

1

Nanno.

Events

7940' 8.5Ma SB7977' 9.5Ma MFS

9367' 10.35Ma SB

9458' 10.4Ma MFS

10358' 10.6Ma SB

10558' 11.5Ma MFS

11112' 12.1Ma SB

11171' 12.8Ma MFS

11292' 13.1Ma SB

Depth

2500'

2750'

3000'

3250'

3500'

3750'

4000'

4250'

4500'

4750'

5000'

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

Gamma Log(API)0 150

Lit

ho

log

y


Lit

ho

stra

tig

rap

hy

2400

Be

nin

Fo

rma

tio

n7461

11460

Ag

ba

da

Fo

rm

atio

nF

orm

atio

n

Se

qu

en

ce

2400

LO

WS

TA

ND

PR

OG

RA

DIN

G C

OM

PL

EX

7461

HS

T

7984

TS

T

8951

LO

WS

TA

ND

PR

OG

RA

DIN

G C

OM

PL

EX

10359

HS

T

10562

TS

T

HST11170

11460

TS

T

Div

ers

ity: M

icro

pa

lae

on

tolo

gy

25

In-S

itu o

ccurren

ces

12

8

10

5

7

4

10

8

9

9

7

5

7

4

5

6

4

5

12

11

8

9

7

5

9

9

4

14

16

13

8

7

3

3

2

5

3

1

9

10

13

10

2

5

6

4

12

16

5

9

7

7

6

10

8

12

7

15

9

5

8

13

3

4

7

4

4

15

5

8

8

26

7

2

2

1

1

1

425

17

4

1

11

5

6

7

3

420

121

2

4

3

5

28

2525

32

29

3

9

232

3

1

8

1

10

5

9

16

13

5

8

3

2

10

514

10

10

5

1

224

925

1

2

1

264

4

4

3

318

6

7

10

16

614

9

10

326

8

8

Micro.

To

tal co

un

t: M

icrop

ala

eo

nto

log

y

20

In-S

itu o

ccurren

ces

21

16

18

6

15

5

18

16

17

17

15

6

10

8

9

11

4

9

21

19

16

13

15

9

17

17

4

24

33

36

8

10

3

4

2

6

3

1

14

19

24

17

3

8

6

5

21

41

5

12

10

18

13

17

17

44

12

46

17

7

23

27

7

5

12

5

4

35

5

28

16

130

14

3

3

1

1

2

410135

12

3

30

13

11

7

3

512244

1

3

8

3

7

64

150105

117

116

3

13

2137

4

1

11

1

18

7

19

32

28

7

13

3

8

13

524

12

32

5

1

2141

1265

1

3

2130

7

4

4

6

645

8

18

13

24

924

15

16

3168

11

9


Default

Non M

arin

e

Transitio

nal

Inner

Neritic

Mid

dle

N

eritic

Div

ers

ity: N

an

nop

ala

eo

nto

log

y

15

In-S

itu o

ccurren

ces

1

1

3

21

111

4

54

86

61

82

1

3

1

2

1

11

99

1

25

1

8

1

1

1

2

22

41

1

1

5

1

8

3

4

Nanno.

To

tal co

un

t: N

an

no

pa

lae

on

tolo

gy

20

In-S

itu o

ccurren

ces

3

1

5

21

1

1

1

5

65

98

61

1121

4

1

2

1

1

1

2438

1

27

1

11

1

3

1

2

22

91

1

1

7

1

11

3

9

Nanno.

Events

7460' 10.35Ma SB

7983' 10.4Ma MFS

10359' 10.6Ma SB

10561' 11.5Ma MFS

11170' 12.1Ma SB

Depth

4000'

4250'

4500'

4750'

5000'

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

11500'

Gamma Log(API)0 150

Lit

ho

log

y


Lit

ho

stra

tig

rap

hy

4000

BE

NIN

FO

RM

AT

ION

7462

11600

AG

BA

DA

FO

RM

AT

ION

Fo

rm

atio

n

Se

qu

en

ce

4000

LO

WS

TA

ND

PR

OG

RA

DIN

G C

OM

PL

EX

HST8018

TS

T

8469

LO

WS

TA

ND

PR

OG

RA

DIN

G C

OM

PL

EX

HST

TST9703

LO

WS

TA

ND

PR

OG

RA

DIN

G C

OM

PL

EX

11114

HS

T

11375

11600

TS

T

To

tal co

un

t: M

icrop

ala

eo

nto

log

y

40

In-S

itu o

ccurren

ces

24

33

36

8

10

3

4

2

6

3

1

14

19

24

17

3

8

6

5

21

41

5

12

10

18

13

17

17

44

12

46

17

7

23

27

7

5

12

5

4

35

5

28

16

130

14

3

3

1

1

2

4101

2

12

3

30

13

11

7

310

5122

1

44

3

8

3

7

64

150105

117

116

3

13

2

137

4

1

11

1

18

7

1922

3228

327

13

3

8

13

524

12

32

5

1

2

14112

1

3

2

7

4

4

6

645

8

18

13

24

159

15

16

3168

1117

9

25

56

43

Micro.

Div

ers

ity: M

icro

pa

lae

on

tolo

gy

15

In-S

itu o

ccurren

ces

14

16

13

8

7

3

3

2

5

3

1

9

10

13

10

2

5

6

4

12

16

5

9

7

7

6

10

8

12

7

15

9

5

8

13

3

4

7

4

4

15

5

8

8

26

7

2

2

1

1

1

425

2

4

1

11

5

6

7

39

420

112

2

4

3

5

28

2525

32

29

3

9

232

3

1

8

1

10

5

913

1613

165

8

3

2

10

514

10

10

5

1

2

249

1

2

1

4

4

4

3

318

6

7

10

16

136

9

10

326

814

8

13

19

18


Default

Non M

arin

e

Transitio

nal

Inner

Neritic

Mid

dle

N

eritic

Div

ers

ity: N

an

nop

ala

eo

nto

log

y

20

In-S

itu o

ccurren

ces

1

1

3

21

1

1

1

4

54

86

61

821

3

1

2

1

1

1

9

9

1

25

1

8

1

1

1

2

22

41

81

1

5

1

3

4

5

Nanno.

To

tal co

un

t: N

an

no

pa

lae

on

tolo

gy

25

In-S

itu o

ccurren

ces

3

1

5

21

1

1

1

5

65

98

61

1121

4

1

2

1

1

1

24

50

1

27

1

11

1

3

1

2

22

91

321

1

7

1

3

9

7

Nanno.

Events

7933' 10.35 Ma SB

8018' 10.4 Ma MFS

9547' 10.6Ma SB

9623' 11.5Ma MFS

11113' 12.1Ma SB

11374' 12.8Ma MFS

Depth

4000'

4250'

4500'

4750'

5000'

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

11500'

11750'

12000'

12250'

12500'

12750'

13000'

Gamma Log(API)0 150

Lit

ho

log

y


Lit

ho

stra

tig

rap

hy

4000

Be

nin

Fo

rma

tio

n

7560

13000

Ag

ba

da

Fo

rm

atio

nF

orm

atio

n

Se

qu

en

ce

4000

Lo

wsta

nd P

rog

rad

ing

Co

mp

lex

8717

HS

T

10689

TS

T

10884

Lo

wsta

nd P

rog

rad

ing

Co

mp

lex

HST11885

TS

T

12615

HS

T

12819

13000

TS

T

Samples

Barre

n

4040

4100

4160

4220

4280

4340

4400

4460

4520

4580

4640

4700

4760

4820

4880

4940

500050105060

5120

5180

5240

5300

5360

5420

5480

5540

5600

5660

5720

5780

5840

5900

5960

6020

6080

6140

6200

6260

6320

6380

6440

6500

6560

6680

6740

6800

6860

6920

6980

7040

7100

7160

7220

7280

7340

740074447460

7520

7580

7640

7700

7760

7820

7880

794079788000

8060

8120

8180

8240

8420

8480

8540

8600

86608661

8720

8780

8840

8900

89608962

9020

9080

9140

9260

9320

9380

9440

9500

9560

9620

96739680

9740

9800

9860

9920

9980999410040

10100

10160

10220

10280

1033610340

10400

10460

10520

10580

106401068910700

10760

108201087110880

10940

11000

11060

11120

11180

11240

113001130811360

11420

11480

11540

11600

11660

11720

1178011787118401188511900

11960

12020

12080

12140

12200

12260

12320

12380

12440

12500

12560

1261512620

12680

12740

128001281912860

12920

Div

ers

ity: M

icro

pa

lae

on

tolo

gy

20

In-S

itu o

ccurren

ces

14

16

13

8

7

3

3

2

5

3

1

9

10

13

10

2

5

6

4

12

16

5

9

7

7

6

10

8

12

7

15

9

5

8

13

3

4

7

4

4

15

5

8

8

26

7

2

2

1

1

1

425

2

4

1

11

5

6

7

3

420

1

2

4

3

5

28

2525

32

29

3

9

232

3

1

8

1

10

5

9

16

13

255

8

3

2

10

514

10

10

5

1

2

249

1

2

1

4

412

4

3

318

6

7

10

16

6

9

10

326

8

8

13

19

18

11

10

920

1126

9

23

7

8

7

2

3

8

6

6

7

2

57

8

6

316

4

8

Micro.

To

tal co

un

t: M

icrop

ala

eo

nto

log

y

50

In-S

itu o

ccurren

ces

24

33

36

8

10

3

4

2

6

3

1

14

19

24

17

3

8

6

5

21

41

5

12

10

18

13

17

17

44

12

46

17

7

23

27

7

5

12

5

4

35

5

28

16

130

14

3

3

1

1

2

4101

2

12

3

30

13

11

7

3

5122

1

3

8

3

7

64

150105

117

116

3

13

2

137

4

1

11

1

18

7

19

32

28

687

13

3

8

13

524

12

32

5

1

2

14112

1

3

2

7

444

4

6

645

8

18

13

24

9

15

16

3168

11

9

25

56

43

21

14

1140

1898

23

61

15

16

15

2

3

16

13

7

8

2

815

16

11

332

4

16


Default

Non M

arin

e

Transitio

nal

Inner

Neritic

Mid

dle

N

eritic

Samples

Barre

n

40104040407041004130416041904220425042804310434043704400443044604490452045504580461046404670470047304760479048204850488049104940497050005030506050905120515051805210524052705300533053605390542054505480551055405570560056305660569057205750578058105840587059005930596059906020605060806110614061706200623062606320635063806410644064706500653065606590662066506680671067406770680068306860689069206950698070407100713071607190722072507310734073707400743074447490752075507580761076407670770077307760779078207850788079107940797079788000803080608090812081508180821082408270830083308360839084208450848085108540857086308660866186908720875087808810884088708900893089608962899090209050908091109140917092009230926092909320938094109440947095009530956095909620965096809710974097709800983098609890992099509980100101004010070101001013010160101901022010250102801031010336103401037010400104301046010490105201055010580106101064010670106891070010730107601082010850108801091010940109701100011030110601109011120111501118011210112401127011300113081133011360113901142011450114801151011540115701160011630116601169011720117501178011810118401187011885119001193011960

12819

Div

ers

ity: N

an

nop

ala

eo

nto

log

y

10

In-S

itu o

ccurren

ces

1

1

3

21

111

4

54

86

61

82

1

3

1

2

1

11

9

1

25

1

8

1

1

1

2

22

41

1

1

5

1

9

3

4

1

8

5

Nanno.

To

tal co

un

t: N

an

no

pa

lae

on

tolo

gy

12

In-S

itu o

ccurren

ces

3

1

5

21

111

5

65

98

61

112

1

4

1

2

1

11

24

1

27

1

11

1

3

1

2

22

91

1

1

7

1

34

3

9

1

11

18

Nanno.

Events

9673' 10.35 Ma SB

10689' 10.4 Ma MFS

11786' 10.6Ma SB

11885' 11.5Ma MFS

12615' 12.1Ma SB

12819' 12.8Ma MFS

Depth

4000'

4250'

4500'

4750'

5000'

5250'

5500'

5750'

6000'

6250'

6500'

6750'

7000'

7250'

7500'

7750'

8000'

8250'

8500'

8750'

9000'

9250'

9500'

9750'

10000'

10250'

10500'

10750'

11000'

11250'

11500'

11750'

12000'

12250'

12500'

12750'

13000'

Well Name : TOMBOY-1Operator : TOMBOY


Lat/Long : 52°31' 25.01"N 2° 2' 3.00"E

Interval Various

Scale Various

Chart date: 28 January 2003 Project

Chart

: BIOSTRAT

: TOMBOY-CORRELATION

TOMBOY-1 TOMBOY-2 TOMBOY-4 TOMBOY-5 TOMBOY-6

Base Lithology

clay

shale/mudstone

silty mudstone

sandy mudstone

siltstone


sandy siltstone


sandstone (coarse)



Text Keys*1 Palaeoenvironment

*2 Default

CH

RO

NO

(AG

E)

MA

RTI

NI (

19

71

)

THIS

STU

DY

BIO

ZON

E

BIO

EVEN

TS

BIOZONATION AND CORRELATION OF XY-1 FIELD, OFFSHORE WESTERN NIGER DELTA, NIGERIA Well Names: TMB-1, 2, 5 & 6

Interval: Various

Scale: 1:5000

Chart Date: 06 August, 2008LA

TE M

IOC

ENE

MID

DLE

MIO

CEN

E

NN

9N

N8

NN

7N

N6

DIS

CO

AST

ER H

AM

ATU

SC

ATI

NA

STER

CO

ALI

TUS

CA

LCID

ISC

US

PR

EMA

CIN

TYR

EI

FDO: DISCOASTER HAMATUS (9.5 Ma)

LDO: DISCOASTER HAMATUS (10.4 Ma)

LDO: CATINASTER COALITUS (11.5 Ma)

FDO: CALCIDISCUS PREMACINTYREI (12.8 Ma)

LATE

MIO

CEN

E

FDO: DISCOASTER HAMATUS (9.5 Ma)

MID

DLE

MIO

CEN

E




CA

LCID

ISC

US

PR

EMA

CIN

TYR

EIC

ATI

NA

STER

CO

ALI

TUS

DIS

CO

AST

ER H

AM

ATU

S

NN

9N

N8

NN

7N

N6

CH

RO

NO

(AG

E)

MA

RTI

NI (

19

71

)

THIS

STU

DY

BIO

ZON

E

BIO

EVEN

TS

Lith

olo

gy

CH

RO

NO

(AG

E)

MA

RTI

NI (

19

71

)

THIS

STU

DY

BIO

ZON

E

BIO

EVEN

TS


NN

7-N

N9

UN

IDEN

TIFI

ED Z

ON

E

MID

DLE

–LA

TE M

IOC

ENE

CH

RO

NO

(AG

E)

MA

RTI

NI (

19

71

)

THIS

STU

DY

BIO

ZON

E

BIO

EVEN

TS




CA

LCID

ISC

US

PR

EMA

CIN

TYR

EIC

ATI

NA

STER

CO

ALI

TUS

NN

9N

N8

NN

7

MID

DLE

MIO

CEN

E

CH

RO

NO

(AG

E)

MA

RTI

NI (

19

71

)

THIS

STU

DY

BIO

ZON

E

BIO

EVEN

TS




CA

LCID

ISC

US

PR

EMA

CIN

TYR

EIC

ATI

NA

STER

CO

ALI

TUS

NN

9N

N8

NN

7

MID

DLE

MIO

CEN

E

UN

IDEN

TIFI

ED Z

ON

E

NN

6

LATE

MIO

CEN

E

UN

IDEN

TIFI

ED Z

ON

E

NN

6

LATE

MIO

CEN

E

Figure 7: Calcareous Nannofossils Biozonation Correlation Chart of XY-1 Field

1 2

3 4

5 6

7 8

9 10

11 12

13 14

scale bar: 10 µm

1. Cyclicargolithus floridanus (ROTH & HAY)

2. Reticulofenestra pseudoumbilicus (GARTNER)

3. Reticulofenestra haqii BACKMAN

4. Coccolithus pelagicus (WALLICH)

Figure 8: Photomicrographs of Marker Species



5. Calcidiscus leptoporus (MURRAY AND

BLACKMAN)

6. Calcidiscus premacintyrei THEODORIDIS

7. Sphenolithus heteromorphus DEFLANDRE

8. Discoaster bollii MARTINI & BRAMLETTE

9. Discoaster exilis MARTINI AND BRAMLETTE

10. Discoaster braarudii BUKRY

11. Discoaster bellus BUKRY AND

PERCIVAL

12. Discoaster hamatus MARTINI &

BRAMLETTE

13. Catinaster calyculus MARTINI &

BRAMLETTE

14. Catinaster coalitus MARTINI &

BRAMLETTE

REFERENCES

[1]. Avbovbo, A. A., 1978. Tertiary lithostratigraphy of Niger

Delta, AAPG Geol. Notes, pp. 296-300.

[2]. Berggren, W. A., Kent, D. V. and Avan Couvering, J. A.,

1985. The Neogene: Part 2, Neogene geochronology and

chronostratigraphy. In: Snelling, N.J. (Ed.), The

Chronology of Geological Record, Geological Society

Memoir, 10: 211-260.

[3]. Bolli, H. M. and Saunders, J. B. and Perch-Nielsen, K.,

1987. Planktonic stratigraphy. (Cambridge Earth

Sciences Series), Cambridge University Press, 599 pp.

[4]. Doust, H. & Omatsola, E., 1990. Niger Delta. In: Edwards,

J.D. & Santogrossi, P.A. (Eds.), Divergent/passive

margin basins, American Association of Petroleum

Geologists Memoir 48: 201-239.

[5]. Esan, A. O., 2002. High resolution sequence stratigraphic

and reservoir characterization studies of D-07, D-08 and

E-01 sands, Block 2 Meren Field, Offshore, Niger Delta,

Publ. M.S. Geology Thesis, Texas A & M University,

Texas, USA, 115 pp.

[6]. Frankl, E. J and Cordy, E. A., 1967. The Niger Delta oil

province recent development onshore and offshore: 7th

World Petroleum Congress Proceedings, Mexico City, IB:

195-209.

[7]. Knox, G. J. and Omatsola, E. M., 1989. Development of

the Cenozoic Niger delta in terms of the “escalator

regression” model and impact on hydrocarbon

distribution, in W.J.M. van der Linden et al., eds., 1987,

Proceedings, KNGMG Symposium on Coastal Lowlands,

Geology, Geotechnology: Dordrecht, Kluwer Academic

Publishers, 181-202.

[8]. Martini, E., 1971. Standard Tertiary and Quaternary

calcareous nannoplankton zonation, in Proceedings of the

Second Nannoplanktonic Conference, Roma, 1970, (ed.

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Calcareous Nannofossil Biostratigraphy of XY-1 Field,Offshore Western Niger Delta, Nigeria

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