upper cretaceous - lower paleogene foraminiferal ...

Egypt. J. Petrol. 9, pp. 105-/22 (2000)

UPPER CRETACEOUS - LOWER PALEOGENE FORAMINIFERAL PALEOECOLOGY OF NORTH AND SOUTHWEST SINAI AREAS, EGYPT W.Z.M. El-Deeb, M. Faris* and M.M. Mandour Egyptian.Petroleum Research Institute, Nasr City, Cairo, Egypt. • Dep. ofGeoloey, Faculty ofScience, Tanta Uni. Tanta. Egypt. Received August 7, 2000; Accepted November 2, 2000 The planktic and benthic, foraminifers of the Upper Cretaceous - Lower Paleogene successions exposed at north and southwest Sinai in Egypt have been studied 10 contribute in the understanding of the paleoeco logy, paleobathymetry and tecto nic history of these sed imentary sequences. These sediments are subdivid ed into three rock units (from olde r 10 younger): Sudr, Esna and Thebes Formations. Acco rding to its planktic foram iniferal content the succession is subdivided into thirteen biozones. The studied, succession is divided into five and nine ecozo nes in north and southwest Sinai areas respecti vely (after their foraminifera l content). The environment of eac h ecozone is deduced. These environments point to bathyal depths for the Sudr Formation and an outer neritic to bathyal environment for the Esna Formation in southwest Sinai and littoral 10 midd le neritic one in north Sinai. II indicates, also, that the Thebes Formation was deposited in outer neritic conditions in southwest Sinai and in middle nerit ic conditions in north Sinai. A proposed paleobathyme tric curve is presented. The interpretation of this curve helped to deduce the tectonic history of the Upper Cretaceous >Lower Paleogene sed iments in the stud ied areas.

Key Words: Cretaceous, Paleogene, F6raminifera, Paleoecology, Paleobathymetry, Ecozone.

I NTRODUCTION The present work deals with the foraminiferal paleoecology of the Upper Cretaceous Lower Paleogene succession of the north and southwest Sinai areas, Egypt. This study is based mainly on samples collected from four outcrop sections. Two sections from north Sinai area, EI Hassana section (latitude 30' 30' N and longitude 33' 45' E) and Gebel Yellg section (latitude 30' 20' N and longitude 30' 35' E). The other two sections from the southwest Sinai area are: Wadi Feiran section (latitude 28' 40' N and longitude 330 28') and Gebel Matulla section (latitude 29' 5' N and longitude 33' 10' E), see Figure ( I) .

The sequence of the studied sections is subdivided into three rock units, these are arranged chronologically as follows from base to top: 1- Upper part of the Sud r Formation, it is of Maastrichtian age arid consists of white to grey. bedded chalky limestone, partly marly and grading into creamy marlstone in its lower part. It underlies conformably the Esna Formation. 2- Esoa Formation, is composed of laminated green and grey marl and shale intercalated with several argillaceous and chalky limestone ledges. Its age ranges from the Late Maastrichtian to the Early Eocene. It overlies conformably the Sudr

106

W.Z.M. EI-Daab at al.

Formation and underlies conformably the ThebesFormation. 3- Thebes Formation, it consists of massive limestone intercalated with chert bands and nodules. It overlies the Esna Format ion and underlies the Appolonia Formation of Early Eocene age.

•

" MEDITURAllflAH StA

\

,,' [L-H ASSAN4

The foraminiferal fauna separated from the studied 249 samples comprises 58 planktic foraminiferal species belonging to 21 genera (Fig. 2) and 11 6 benthic species belonging to 53 genera (Fig . 3,4), According to this fauna the stud ied succession has been subdivided into 13 biozones (1). Accounts on the paleoecology of similar sediments in Egypt are given by (1-21) and others.

PALEOECOLOGIC INDICATORS The paleoecologic indicators which are used in the present study include:

, ,

"

, ,,

\, •,

•

(; [ Ir.L VILLe •

,, ,

" ,

.

0

so

n'

WAD IPl:I RAN

0 [ ASTER N

'.

DUIER T

"

••

n'

Figure 1; Location map of the studied sections in north and southwest Sinai areas, Egypt. 3- Benthic Foraminiferal Groups:

1- Frequency:

It is considered here as the average number of individuals of a given foraminiferal species in a fixed volume of sediment in each sample )22). 2- Planktic Foraminiferal Groups: The identified planktic foraminiferal taxa are subdivided into three groups (heterohelicidae or uncoiled planktics, unkeeled and keeled or coiled planktics) (23-24) . Fig. (5) gives lists of the genera belonging to each group.

Egypt. J . Petrol. 9 (2000)

>0"

~

'

cnu. MA TU LU.

,;

,.

~ \, •. c= ..

"

SIN"'I

,,'

The identified benthic foraminiferal genera are arranged into five ecologically significant groups. They are arenaceous, millolidae, nodosariidae, buliminidae and rotaliidae )24-26) . Fig. (5) shows the genera belonging to each of the mentioned five groups. 4- Diversity:

It is expressed here as the total number of species in a sample or at anyone time interval (23, 27, 28) .

UPPER CRETACEOUS-LOWER PALEOG Et\1: FORAMINIFERA

_.-

~

i

I

f

. ~

~

1

ir i r

....

-fTi

~­

,

• '"0-

I ~

1 I t•

J

a•

.,a. ..,;;tr

1 :!l II •l r l

n

,

e

g

I _

, I

I

I

i

-

I

1-

-

I I

j

I

I

I

i

I

I

I

I

I

I

i I

1

I

I

;

I I

I

I

I I I

I-I--

i

I

I

I

I

I

I

I

I

I I j'

I

•

I

Q

1 I

I ,

I I

I

I

.

$

Ott

au'

1

..

,

_~ .

I--l---l---+--j I-I-

1---1- -+- _

--'

:

t=-~;-. . t _. ..• . - !- .- .: ,

--~-t~

•

--

la s ,

,I

,"

- ~ -- - - ~ - - . . ._- ..

--

• •

---

!

1

-_ t~ -:--

. -

.,

.....-.... .u........ .. ~

...

""

'.

'

."-'-'.,..e-

---

_J r , I __ .--,--" -v4 .

•

$ • • ~'-"

-

~

•

t

- . .....

.-

J

.,

.~

"4

C'

I. _

t

• rc"

"f

._- 1-- ----:-.. . --~-

__

i

- ! --

."

$

-.. ..... -- ... --. 1:1'

I __• .

b

'

I

~ , ~ --

'

.e,»,.

I

I

I--+--t--+--j - - .

---.ll......... -......... -- •

, --

b

--

m

I

,..

--

:

-,

•

... , - - f • 5 IU"-

I I

I ---I- + - +-- f-- '

d

•

I

' i

I

I-I-~~J-

Ai:a'

----- --! ~

I

I

I-I--

" ~.

I

I I

1-

107

A

- co '

..

~

,

r _

•

'WI ,.,."..,"

-

•

-

-----...4 0

L-:t.....

J

•

Fig. (2) Composite stratigraph ic ra nge cha rt of the identified Upper Cretaceaus _ Lower Paleogene plan kite foram ini feral species recognized in the studied areas (not to scale).

Egypt. J. Pe trol. 9 (2000)

108

• ..

•

W.Z.M. EI-Deeb et al.

Bio stratigraph ic un its

. . . . ... . .

: Sample No.

....

c-r- '

Gyroldlnold• • n lt/d u s

-: 1-

O• • "gul.rla c ordl,ri.n.

-

~+-

G.udryln.

p~,"ld.u

Dorolhl. oxycon. NodouTil /lmb.'.

Frondlcul.ri. goldfus.1

ug.n.

!-r- -

I- c-

globou

N. on.lHl lI". rvgo,.

PI2.bullmln. cushm.nl Bo/lvl". In c ,..•••'.

Eouttfg .rln. " flyp t/~

-

-- ,- 1- 1-

.. f- f- ..

f- - '- .

Slphog .n.rlnold• • o W'yI

.

Gfo borol."', . t.pp.n••

1.;

L

G. ~lIn.lI.

H .... ....

' 1-

" .utoch .n.I,

G,".lIn,lI. h .nb. ,tI

/I".". camp,.....

e.....

G~/dMOld•

I

• b.ndyi

Gyro/dln.I;,.,. c..

8 .thyslphon .twn.c.ou. G.udryfn. rogo•• G.udryfna I•• vlg.t• . I

-

~.

~ .

l

I

I

•

-+

J

:~ -

I

Doro th/6 bull.ft.

PuudocJ.YfJIJn.I.,..t,...n.' Nodo ..rl•• mnl• Nodo , .ri• •mphlorys

4 '~ ;

D.,,'.lln. C61.nul. D.nt.nn. gracll/.

!-I--- --

-i I . •

+--:--+ -~

•

L69'''••p lcul.'• £"., ,,Jd • • " g . /I

i I

I · .-1-;- I . .... ....

..-

S ol/rin o ld.s drs c o

i -f-tH

D.nl. lln. bl s /p l. n.,.

D.nl.II". m .rck' I

~ _. I ~ .

. ;- ~ .

O.nl.II". '-gum . "

I j

- I-+ ' ~ -1-1- ' i

j _ ~ _ . : " ' _ : -1

i - f- c- ...l. !.J.

C. v.lln .lI~

. v. lln. "~

wh it. ,

s . n d/g.1

Ou lnqu./oculln . h .m,1

Frond/cui.,;. '" t, nniN . " . L ~g .n .

s/.un.l.

LAg .n. h1. p ld6

ug.n. gnh.m l L. n tlc ulln. m od.st.

--

L. n tlculln" .ylo,...". '. L.nllc u lln . c l rlsb.. d . n s l. ( fOn d lcu ,.. rll cI.rlt l _

. •

MI 'll/n u l/n o p s ls I . .. . . n t ' s

. . :_J _ t-

~.

Fig. (3) Composite stratigraphic ra nge chart of th e ide ntified Upper Cretaceo us benthic foraminiferal species recognized in the studied areas (not to scale).

@ = Globotruncana aegyptiaca Zone.

Egy pt. J. Petrol. 9 (2000)

UPPER CRETACEOUS-LOWER PALEOGENE FORAMINIFERA

.----..- -.- - --1-

1_

,_

,.....1Hr\

_.-

•

1_

1 __

:

L.

I • - ...

"-f-. - ·-H-- H I-+-·-t-'--4

--,..,.....

I I I I

I

I ,

I

J

I

'

j

I

I

I

I

I

!

!:

I

I

' •

I

:

i ii:

~

:

I

I I I I I

,......c._fII'Inb

I

I

t

I

I

t

I

I

I

I I , II

I

I

I

,.

,

I I

-,

....... -_. _..--

I

'

I

J

I

I

-,... ............,.,,.,,.,

I

I

I

I

I ,

I

I

+

,

lOt

I I

•

I.....

m,..~

--

,...,."..~.

I

.1 "

I

I

--;-

01" cq

I

",./WtCM

.

[,....,. ...... _W'II-.h

Ft ' ,

I I

.....,.-,.

".~.,.

~

I

,

II tNfIwe,NM

-" ..,...,.

I I

, I I I ;

. -r.,.... "

I

I I

1 ! I

1

'

i

I i ' "

--

I

,

I

, II

I

I

•

t ;

~.M_.

I

I

! I; I

,.

I I

J

'

,.".......

..........

I

I

,,_Its

-_. -_. --'".... .

J IJ'

I 1-

JA,.

- - . . . . . . . dn. ., . '.. k

J

109

• "

~.ttI.

aIH......... ~.

l . ..---J I

I

T

,.

",.

.

..~

,

,.~.,

=

Fig. (4) Composite stratigraphic range chart of the identified Lower Paleogene benthic foraminiferal species recognized in the studied areas (not to scale).

• Morozovella edgari Zone. Egyp). 1. Petrol. 9 (2000)

W.Z.M. EI-Deeb et al,

110

Foraminiferal group Heteroh elicidae u

.-

-

Unkeeled

.:.: c

Heterohelix, l'seudoguembelina. Planoglobulina, Pseudotextularia, Racemiguembelina, Chiloguembelina. Rugoglobigertan, Hedbergella, Archaeoglobigerina, Globigerinelloides,

Shallow

marine

.-.

Intermediate manne

Pseudohastigerina.

Q"

Keeled

Rosita, Globcu uncana, Gansserina, Abathomphalus, Morozovella.

Deep marine

Arenaceous

Bathysiphon, Gaudryina, Dorothia, Pseudoclavulin. Spiroplectammina, Clavulinoides, Textularia, Tritaxia, Vulvulina.

Littoral and shallow marine

Miliolidae

Quinqueloculina, Spiroloculina.

Littoral and shallow marine

Nodos ariidae

Nodosaria, Frondicularia, Lagena, Dentalina. Lenticulina, Saracenaria,

Intermediate to deep marine

.-

Marginulinopsis, Neoflabellina,

.c

Astacolus, Va,:/11l1linopsis, Orthomorphina, Marginullina

-

Environment

Globo truncanclla, Globoconusa, Planorotalites, Globigcrina, Aconnina,

-"

u

Genera

Buliminidae

c 4J CQ

Proebulimina, Bolivina, Bolivinoides, Eouvigerina, Siphogenerinoides, Coryphostoma, Loxostomum, Bulimina. Tappanina, Stillostomella, Quadrimorphina, Trifarlna,

Intermediate to deep marine

Zcauvigcrina, '.osostomoides. Rotaliidac

Gyroidinoides,. Gyroidina, Osangularia, Eponides. Globonnalites, Gavelinella, Cibicides, Heterolepa

Shallow to decp marine

Anomalinoides, Chilostomclla, Valvulineria, Putlenta, Cibicidoides, Karreria, Alabamina, Anomaltna.

Fig. 5: Genera belonging to both planktic and benthic ecologically significant fonniniferal groups of the studied samples in north and south west Sinai (bathymetric interpretation after Boersma and Premoli-Silva, 1983 and Martine, 1989).

Egypt. J. Petrol. 9 (2000)

UPPER CRETACEOUS-LOWER PALEOGENE FORAMINIFERA

5- Planktic/Benthic (PIB) Foramini-

Feral Ratio: In the present work, this ratio is determined for each sample in the four studied sections. Then for each biozone the arithmetic mean of these ratios is calculated as a standared value characterizing the stratigraphic interval covered by the biozone (29-32 and others) .

6- Arenaceous / Calcareous (AlC) Benthic Foraminiferal Ratio: The same method of calculating P/ B ratios is followed to get the AlC ratios (33] .

7-

Benthic Genus/Genera Minance:

Predo-

Poag (34) define this concept as the genus or genera that comprise the highest proportion of a benthic population having paleoecologic meaning. The different values of the seven above-mentioned paleoecologic indicators in each studied section are tabulated in figures 6&7. The average values of these indicatores, for the composite logs of the studied four sections, are tabulated in the tables of figures 8& 9.

FORAMINIFERL PALEOECOLOGY According to the statistical data represented by the previously mentioned paleoecologic indicators, the successi?n~ of the two sections of the north Sinai area were subdivided into five ecozones (Fig. 8). The succession of the other two sections (in southwest Sinai area) were subdivided into nine ecozones (Fig. 9).

111

The environment of each ecozone is deduced and a proposed paleobathymetric curve is drawn for the successions of the two areas (Fig. (0) . In the studied successions, five bathymetrically significant groups of foraminiferal assemblages can be recognized according to Berggren's (31) model:

1- Littoral assemblage (0-10 m), It is represented only in the north Sinai area succession by the ecozones no. 1 & 4 (Fig. 8). It is characterized by very low

frequency, very low percentage of heterohelicid and unkeeld planktic foraminifers, very high percentage of benthic foraminifers with predominance of nodosariid and rotaliid, very low PIB ratio, very low AlC ratio in warm conditions and the predominant benthic genera were Nodosaria, Gavelinel/a and Cibicides.

2- Inner neritic assemblage (10-30 m). it is represented, also, in the succession of north Sinai area only by ecozone no. 2 (Fig. 8). It is characterized by low frequency, low percentage of unkeeled planktic foraminifers, high percentage of benthic foraminifers with predominance of rotaliid and nodorariid, very low diversity, low PIB ratio, no arenaceous benthic foraminifers and the predominant benthic genera were Cibicides and Lenticulina.

3- Middle Neritic Assemblage (30 tOO m). it is represented in the north Sinai area succession by the ecoznoes no. 3 and 5 (Fig. 8). In southwest Sinai it is represented by ecozones no. 3 and 7

Egypt. J. Petrol. 9 (2000)

112

W.Z.M. EI-Deeb et al.

M .. :t "iI r idll iot

Sudr

·~ H

~

i'

•• ! ::

"I , ~

··• .l• 3 ·- HH 3 I

~ -I ~ ~.

~ • l a ~

~ Q

.. .. ~

0

"

E

..- f

. ~ • t , ,. n-

.~ ~

I

(b nian

T h.u,,:l i:.l n

S

N

.

A

I

"" p rlo,i;111

.

IT hr hu

. . .- • i• .;.!i, :1 ...U

1!

, : 1 •~ •' ~ , • ..~ ~t :-. ~ ~ ; ~ , .. ! ! ~

.' .. ..

! ~

•

~

; ~

•

-

~

w

w

;;

~

;;-

i~ ~ . .t t~ d , $;~ ~ ~ t;. r• ;: ii= !• ii • • ~~

1£

"~

;;;

'"

.., •

•"G-

• -!'

. .,...

.. OS

A ~ t'

Fnrm a tinn

r-

.. ·..

..

s

o

:>:

•;;.

-,, Co

0

" !:

..

;:;' 0

c

." ~

'" ~ ~

--

~

~

•

w

.. 0

"'

;;

::;

;;

-'s

•

• i

:

:

•

• i

i

•"" •,

J; .

~r

~i

.

~

"

"

""'

" " e-

:::

~

~

•

!, ~

:;:

•i

• i

•i

~

':l :

o • ~

I "G-

is

w

"

~

- -

o ~

H

l:

z ~

· ~

..

;:;' 0

C

."

~

:c ~

.. 0

f;

0

·•·

~

8

-!'

~

~

.•

E

•~

..-

,

"

.. •

s

:: ~

is

~

55-

~

Co

&

"

Ii

~

w

"•

.. ~ :

1, • =' ': 1. , ,.. ,. , " ~ -:• :r • • ~. oj

;'J'S"

•

~~

-•

Ii

r

.. • 0

..• -= ...'. , ..• .. & .,.. ·

....,

~

• •l •

.

~

-s• •

'cr"

e c

00

...

~

-e

;:;'

~

a -c e,

.,

-"" c:

Hiv.

"

rIO

>,:

'..". ..•-..", ~ ..

C)

'" ""e-

~

'.

s

0

c

."

:c

:;:

0'

;:;'

....e

!"

-c

~

...

~

0

c

" !:

• ::::

'... :~

-o'

... -." J. ~

l'

~

~

'" '" '""

Ale

i

;:

w

'"

1'/ 0

·.., .-

0

'" '"

:J

:J

?:

'.

.,

m-.

• !

~~ t- ~ • •• w

...'"

";.

Cl

~

-::r: l"'l

~

A le

...

·

-

•

2- "

.

~. ~ •• ~ ~

Fig. (6) Quantitati\'c foramin iferal dal a obtaincd from Ihe north Sinai ~cclio""

,EgJ.p l, J, Petrol, 9 (2000)

UPPER CRETACEOUS-LOWER PALEOGENE FORAMINIFERA

Maas1ichlian SlIdr

S

I

I

Oanian

··

I

Thanel ian

y

pr~5ian

Ago

I het...

N A

113

'or mJl l iun

i i: ~

..

~;

~.

• ;,

1 ~

,..

.

·• = :;

.•

.

o

.~

•

"=

o

· • · ·•

:: :

;

. ;

~

•

:

:

=

;

;:

::

•=

= = :

··

...

"I>

;

;

."

Ale

2~ :

,l I'

~

N

•

··

s r ss ra e r a rt sa rt s e rs e

••

o

· ;;

· =

·

"•

c:

•

. .• ~

...

-

"

••

s

::

Ui\".

.-• · •· •

Itm . \ 1("

ti .• • ".

•

Fig. (7) Quantitatfve foraminiferal data obtained from the southwest Sinai seclions.

Egyp t. J. Petrol. 9 (2000)

114

W.Z.M. EI-Deeb et al.

, ;

-

.. u

t

r ;

-e

8io zo n~

~

e:

U

~

.c l-

e 0

Morozovella torm os e tormose

-

. •

~

c.

C

C

i".

.;;;

:;c

:;;

>

0'

C

~

.~

u

"..

:;

0:

~

~.

.. '"0: ~

Q

u


-0

... -

.!!

0'

200 m). it is represented, also in the succession of the southwest Sinai area only, in the ecozones no. I, 5, 8 (Fig. 9). It is characterized by moderate to high frequency, very high percentage of unkeeled and keeled planktic foraminifers, low to moderate nodosariid, and arenaceous benthic foraminiferal percentage, low to moderate diversity, very high PIB ratio, low to high NC ratio and predominance of Lemiculina, Marginulina, Sti//ostome//a, Cibicides and Ga velinella benthic genera.

F.gypt. J. Petrol. 9 (20001

PALEOBATHYMETRIC CHANGES AND TECTONIC HISTORY The study of the vertical distribution of the previous mentioned ecozones enables to determine the vertical changes in the bathymetry of the sea and construct a bathymetric curve 1351 for the studied successions in the north and southwest Sinai areas during Maastrichtian, Paleocence and Early Eocene time intervals (Fig. 10). It can be noticed, from the established curves, that they agree with respect to their general shape but that they differ regarding to the absolute depths characterizing each area (Fig. 10). The similarities of the two areas may be related to the effect of the global changes of sea level displayed in the curve of Haq et al. (351 during the Late Cretaceous and the Early Tertiary time interval. The tectonic history of the two studied areas can be discussed separately as follows: 1- The North Sinai Area: It began with a very shallow marine

environment of deposition (Littoral) during the latest Maastrichtian time. At the end of the Maastrichtian the tectonic activity began with a transgressive movement which accompanied the KIT boundary. The effect of this movement remains until the begginning of the Paleocene. It causes the first unconformity in the area (disappearance of the Globigerina eugubina Zone) and changes the environment of deposition into shallow marine environment (inner

UPPER eRETACEOUS-LOWER PALEOGENE FORAMINIFERA

117

'i

t

.g

• !

, I.eOIOM

.: •

.. -

c oS

~

Sea level cbanges in soulhwest Sia.i

20 30 100 200m

20 30 100 200 m

Moro.....,,. _ _

t

~

po

_vol,.

odf1atI

\

. ..

~

_._".--,

_.tas .

(

Ie:: t-:"t>

--[)..