Báo cáo " Quaternary sedimentary cycles in relation to sea level change in Vietnam " pdf

VNUJournalofScience,EarthSciences23(2007)235‐243
235

Quaternarysedimentarycyclesinrelationto
sealevelchangeinVietnam

TranNghi*,NguyenThanhLan,DinhXuanThanh,
PhamNguyenHaVu,NguyenHoangSon,TranThiThanhNhan
CollegeofScience,VNU
Received20November2007;receivedinrevisedform15December2007

Abstract.Vietnam has over 3200 km shoreline which extends from north to south of the country.
Sealevelchangeswere principalfactorsinfluencedonsedimentaryenvironmentandcompositions.
InQuaternary,cyclesofsealevelchangeandtectonicmovementweremainfactorthatcreatedRed
River delta, Nam Bo plain and Central
 plain. There are 5 sedimentary cycles corresponding to 5
cycles of sea level change of the Red River delta and Nam Bo plain. Sedimentary cycles were
characterizedbysedimentarycoefficientssuchas:grainsize,claycontent,indexofcationFe
2+
/Fe
3+
exchange,pHvariationfromthestarttotheendofcycles.Theyarerepresentedbyfluvialterraces,
marine terraces, marine notches and peat layers. In central littoral plain, the relationship between
sedimentary cycles and sea level is represented by five sandy cycles and distribution of coral
terracesinshallowsea.
There
 are 5 generations of ancient shoreline zones, which correlated with glacial and
interglacialperiodsinVietnamesecontinentalshelf:theshorelinein30mwaterdepthiscorrelated
with (Q
2
1-2

). Up to 60 m water depth is correlated with (Q
1
3b
‐Q
2
1
) and 100‐120 m water depth is
correlated with Wurm
2
 glaciation (Q
1
3b
)(?). In 200‐300 m water depth correlated with Wurm
1

glaciation(Q
1
3a
)(?),at400‐500mwaterdepthcorrelatedwithRissglaciation(Q
1
2b
)(?),at600‐700m
waterdepthcorrelatedwithMindelglaciation(Q
1
2a
)(?),andat1000‐1500mwaterdepthcorrelated
with Gunz glaciation (Q
1
1
)(?). As such Quaternary sea level changes in mainland and continental

shelfinteractedandquitedistinctiveformeachotherbypendulumrule.
Keyw ords:Quaternarysedimentarycircles;RedRiverDelt a;CuuLongRiverDelta;Sealevelchange.
1.Introduction
*

Vietnamhas over 3200 km shoreline which
extendsfromMongCaiinthenorthtoHaTien
in the south. Sea level changes had influenced
_______
*Correspondingauthor.Tel.:84‐4‐5587059
E‐mail:
onsedimentaryenvironmentandcompositions
and the evolution sedimentary cycle of Red
RiverDelta,CuuLongRiverDeltaandCentral
Coastalplains.Thesecyclesweredistinguished
by absolute age dating include: thermo‐
luminescence age,
14
C dating from wood and
shells. Geomorphological characteristics and
sedimentary coefficients were used together
TranNghietal./VNUJournalofScience,EarthSciences23(2007)235‐243
236
with absoluteages to analyzethecause‐effect
relationship between development of
sedimentary cycles, sea level changes, and
tectonicmovementinQuaternary.
2.Methodology
There are many research projects have
undertaken by Vietnamese scientists on

Quaternary sea level change, especially in Late
Pleistocene to Holocene. However, the
identification of transgression
and regression
phases and lithofacies analysis based on
quantitative approaches such as material
compositions, geochemical environmental
coefficients,  have just applied by Tran Nghi,
MaiThanhTanandotherworkersin2000,2001
[6, 8]. Therefore, in this paper, we will use the
same approaches to analyze the cause‐effect
relationshipbetween
 lithologicalcharacteristics
and lithofacies associations in relation to
transgressionandregressionphaseandtectonic
movements: fluvial and marine terraces in
mainland and in continental shelf that are
distributed in different height and depth and
compare them to the transgression and
regressionsystemofancientshorelines.
For investigating mechanism of
sedimentary
evolutionofRedRiverDelta,Cuu
Long River Delta and Central plains, it is
necessarytodefinethecause‐effectcorrelation
between lithology, sea level change, and
tectonic movement. The sedimentary
environment has major role in governing
petrological compositions in term of lithofacies
‐ paleogeography. The transgression phase is

characterized by
marshy, lagoonal and deltaic
environments. Meanwhile, regression pha ses
createdcoarse‐grainedmaterialsofproluvial‐
aluvialenvironments.Therefore,therelationship
between sedimentary cycles and sea level
change is determined by changing of facies
associationaccordingtotimeandspace.Theend
of a cycle is marked by a weathering period to
form
laterite‐bearing,yellowtoredsediments.

Vietnam (Tran Nghi) North West Europe
Archaeology
Absolute

age (Ka)
Geological
age
Sedimentary
cycles
Regression

Transgression
Stratigraphy
Regression
Transgression
British Alper (Penk) Italy Middle East
Poland
(Sapherlevin)

Russia
(Lakovlep)
North of
America
(East)
Human
species
Cultural
periods
Q
2
3
?

HOLO-
CENE

Holocene
Flandrian
Transgression
Holocene
Transgression
Holocene
Transgression
Holocene
Transgression
“Nizza”
Transgression
Holocene
Transgression

Transgression
Mogine
Holocene
Transgression
Mesolithic
and
Neolithic
Q
1
3b
-Q
2
3


Regression Regression W
2
Regression
Baltic
Glaciation
Astakop-
vandai
Viskosine (2)
Modern
human
Upper
Q
1
3b
?

Weich-
sebian
Transgression
Regression
Khanstanton
W
1
-W
2
?
W
1

Regression Muzur
Vacsava II
Deglaciation
Mologo sek
nhim Kalinin
V
1
-V
2

Viskosine (1)
Nean-
dectane
Middle
Late

Eemian Transgression
Upper Ixla
Khocnen
R-W
1

Pantinian
Tyrhenian Mazoves II Mikulin
Odinsop

Q
1
2b-3a
?
Saalian Regression Dzippin Riss Regression Vacsava I Dnheprop

Holsterian Transgression
Lower
Khocnen
M-R
? Mazoves I Likhvin
Pre
Nean-
dectan
and pre
Sapien
Lower
Middle
Q
1

2a
?

Elsterian Regression
Logestophoc
Glaciation
Mindel
Regression Krakop Acient
glaciation 1,2

Cromeriam
complex
Transgression Cromerian G-M Cromerian
Roman
crotorian
Sandomir Acient
deglaciation

Q
1
1b
?

Menapian Regression Crue Gun Cassia
Siciian Laroslap Acient
glaciation

Early
Paleolithic
Waal D-G

PLEISTOCENE
Early
Q
1
1a
?
Eburonian


D

Emilian

Tiglian


Practiglian





10

125




700



900


1.6


2-2.5
Ma
PLIOCENE
Reuverian


Heidel-
berg
species

Fig.1.Comparisonofsealevelchange‐glacial‐interglacial‐sedimentarycyclesandgeologicalage[9].

TranNghietal./VNUJournalofScience,EarthSciences23(2007)235‐243
237
Themainmethodsusedinthispaperare:
‐Petrologicalanalysismethodwascarriedout
using thin sections, made by cementing epoxy
ofunconsolidatedsands.
‐Granulometricanalysisofsandwasusedby
sets of sieve or pipet of different fractions and
then granulometric parameters (Sorting‐So,
Asymetric coefficient‐Sk, average
grain size‐
Md)wereobtainedbyaPCsoftware.
‐ Geochemistry environmental coefficientsof
sediments was measured by specialized meter
andthenobtained:pH,Eh,Kt,Fe
2+
/Fe
3+
These
pH‐alkaline‐acidindex,Eh‐redoxpotention
index,Kt=(Na
+
+K
+
)/(K
2+
+Mg
2+
)exchanging
cation coefficients were  applied in lithofacies

association analysis and reconstruction of
paleogeographicallandscape.
3. Transgression‐regression cycles of Red
River Delta, Cuu Long River Delta, Central
plaininQuaternary
RedRiverDelta(RRD)andCuuLongRiver
Delta(CLRD)arethebiggestplainsinVietnam.
Developing history and
sedimentary evolution
of both deltas have closely related with sea
level changes in Quaternary in which
regression were according Gunz, Mindel, Riss,
Wurm
1
,Wurm
2
glacialphasesandtransgressions
were correlated with interglacial phases and 
Flandrientransgression.
Five sedimentary cycles in RRD and CLRD
werecorrelatedwith5stratigraphicformations:
inearlyPleistocene(Q
1
1
),Middle‐LatePleistocene
(Q
1
2-3a
),LatePleistocene(Q
1

3b
),latepartofLate
Pleistocene‐Middle Holocene (Q
1
3c
‐Q
2
2
) and
Late Holocene in each delta (Fig. 1‐6) [2]. The
beginning of a cycle wa s related with coarse
grained size pebbles, sands proluvial and
alluvialfaciessedimentwhatismainlandorigin
and the ending was related with fine grained
sizesilt,claydeltaicandlagoonalfacies.
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140

Depth
(m)
BH59-64
605
BH-11
105
To Lich
river
Red River
BH2-HN
156
BH3-HN
180
BH4-HN
a.amQ
2
3
tb
a.amQ
2
3
tb
apQ
1
2
-3
hn
a.amQ
2
3

tb
am lbQ hh
2
1-2
amQ
1
3b
vp
amQ
1
3b
vp
amQ
1
3b
vp
aQ
1
1
lc
N
2
2
vb
aQ
2
3a
tb
~
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.
aQ
2
3
tb
a.amQ
2
3
tb

Fig.2.Litho‐faciescrosssection
inthecenterofRedRiverDelta[3].
ha no i
Thai
Nguyen
Viet Tri
Phuc
Yen
Son
Ta y
Ha
Dong
Hung
Yen
Hai
Duong
Hai
Phong
Kien
Xuong

Vinh Ni nh
Nam
Dinh
aQ
2
3a
tb
aQ
2
3b
tb
N
2

>

8
0
m
Q
:

6
0

-

8
0
m

1
1

l
c
Q

1
2
-
3
a
h
n
Q
1
3
b

v
p
N
a
m
Q
2
3
t
b

m
m
b
Q
2
1
-
2
h
h
a
m
Q
2
1
-
2
h
h
a
Q
1
3
b
v
p
a
p
Q
1

2
-
3
h
n
a
p
Q
I
I
-
I
I
I
1
h
n
a
p
Q
1
1
l
c
a
p
Q
I
l
c

Red River Dam
Te rr ac e
Aluvial - proluvial pebbles - gravel facies
Plain channel deposited facies
Spotted weathering marine clay
Eroided area
ap
a
m
h
2
h
1
Q
2
1-2
hh

Fig.3.Blockdiagramofalluvialfacies
inRedRiverDelta[11].
Thefirstsedimentarycycle(EarlyPleistocene,
Le Chi Formation in RRD and Trang Bom
Formation in CLRD) are characterized by
coarse grained size sediment with content of
pebbles‐gravel increased from 15 to 20.8% in
RRD and 13.8% in CLRD [2]. The ending of
cycles was correlated with interglacial phase,
silty
claydeltaic‐marshyfacies(Md=0.1‐0.5mm
in RRD and Md=0.018‐0.439 mm in CLRD).

TranNghietal./VNUJournalofScience,EarthSciences23(2007)235‐243
238
During maximum sea level rise, erosion‐
accumulationterraces of55‐70mhigh inNEof
RRD were  formed. Meanwhile, lit hofacies
associationofsandybarriersandlagoonalfacies
isthemainfeatureinCentralcoastalplainfrom
Quang Binh Province to Mui Ne‐Phan Thiet,
BinhThuanProvince.
The second
sedimentary cycle from Middle
‐ Late Pleistocene (Hanoi Formation in RRD
andThuDucFormationinCLRD)iscomprised
by thick pebble‐gravel layer (10‐80 m) of
mountainous river and proluvial facies
(Md=0.2‐1 mm in RRD and Md=2.3 mm in
CLRD[2]).Bytheendofthissedimentarycycle,
rock composition composes of clayish marshy
and clayish silt deltaic facies in Thanh Hoa
plain, RRD, CLRD, and ancient sandy bars,
tombololagoonalfaciesinCentralplain.
Thethird sedimentarycyclecorrespondsto
Late Pleistocene (Vinh Phuc Formationin RRD
and Cu Chi or Moc Hoa in CLRD), which
contains coarse
 and medium grained sands of
riverbedfaciesandpassingupwardsintosand
levee facies, silty clay flood plain and clay
marshy, greenish lagoonal facies. In Central
plain, late Pleistocene transgression phase

createdbigvolumeofwhitequartzsandybars.
However,thesewhitesandhavebecameyellow
sanddueto
infiltrationweathering.
30 30
20 20
10 10
0 0
-10 -10
-20 -20
-30 -30
-40 -40
-50 -50
-60 -60
-70 -70
-80 -80
-90 -90
Tam G ia n
g
la
g
oon
BH 407
BH 314
BH 312
Huong river
Q
1
3b
mQ

1
3b
amQ
2
3
mQ
2
1-2
mvQ
1
2-3a
mvQ
1
3b
aQ
1
2-3a
amQ
1
2-3a
amQ
1
1
aQ
1
1
mvQ
1
1
mQ

1
1
mQ
1
3b
mQ
2
1-2
mvQ
2
3
mQ
2
3
mQ
1
2-3a

Fig.4.Litho‐faciescrosssection
ofThuaThienHuePlain[4].
The fourth sedimentary cycle was formed
duringperiodfromLatestPleistocenetoEarly‐
MiddleHolocene(HaiHungFormationinRRD
and Tan Thanh or Binh Chanh Formation in
CLRD). This sequence is characterized by
Flandrien transgression sedimentary facies
complex and composed of sandy silt of deltaic
facies,claysiltrichin
organicmaterialandpeat
ofmarshy facies. These layers were coveredby

grey‐greenishclayoflagoonalfacies.Thecoastal
plains in Central Vietnam, from Nghe An to
BinhThuanprovinces,composeofacombinat io n
of coastal sandy bars and lagoons occuring
inside sandy bars. The associations of tombolo
and
bay was quite typical in South Central
Vietnam, especially in Khanh Hoa Province.
a
a
a
a
a
a
m
Q
2
2
-
3
a
b
Q
2
2
-
3
a
b
Q

2
2
-
3
a
m
Q
2
1
-
2
a
m
Q
2
1
-
2
a
m
b
Q
2
1
-
2
m
b
Q
2

1
-
2
a
m
Q
2
1
-
2
0
20
-10
0
-20
0
0
20
-100
Lk17
Lk209
Lk214a
Lk31MT
Lk325
500
400
479.6
501.7
396.2
Lk812

339.6
Lk819
203.9
Vam C o Dong
River
Sai Gon River
Lk816
169
Co Chien River
Ham Luong River
Vam C o Tay
River
Dong Nai
River
+
+
+
+
+++ +
+
U
U
U
U
U
U
UU
U
U
U

U
Lk817
75
Lk818
396
Bk11
80
Hau River
Tien River

Fig.5.SedimentarycrosssectioninCuuLongRiverDelta[9].
TranNghietal./VNUJournalofScience,EarthSciences23(2007)235‐243
239
Geological
Age
Age of
Sedimentary
Cycles
TL age
(Ka)
No samples
and place name
Sandy cycles
Lithology
Lithology
Envi.
Envi.
Cycles of
lagoonal plain
Detrital minerals of

sandy barrier
Q (%)
F(%)
R(%)
Sorting
Rounding
Sea level
(Reg -
Trans)
So
Ro
H O L O C E N E
Early - Middle
Late
P L E I S T O C E N E
Early
Middle Late
Late Holocene
Late Pleistocene
Middle Holocene
Late
Pleistocene
Middle - Late
Pleistocene
Late part of.
Early Pleis
10
6
125
700

1.6
Ma
Q
2
3
Q-Q
12
3c 1-2
Q
1
3b
Q
1
2-3a
Q
1
1
14+2
14+2
28+4
48+6
52+7
62+6
85+9
99+19
101+17
103+11
122
>181
>204

108+49
VN44
VN12
VN45
VN37
VN18
VN30
VN15
VN12b
VN31
VN20
VN29
VN32
VN14b
VN14
Bau Trang
Tuy Phong
P. T Airport
Suoi Tien
Chi Cong
S. Song Luy
Suoi Tien
Tuy Phong
Hon Rom
Chi Cong
S. Song Luy
H. Rom
Suoi Tien
Suoi Tien
mv

m
mv
m. mv?
m
mv
m
mv
am, m
am
m
mb
a, am
m
am
a
m
am
a
m
am
a
98-100
95-9892-98
92-98
90-98
0-1.00.5-2.01-3.01.0-2.01.0-3.0
0-1.0
0.5-3.0
1.0-8.0
1.0-7.01.0-7.0

1.2-1.51.3-1.71.3-1.81.5-1.81.5-1.8
0.6-1.0
0.6-0.9
0.5-0.9
0.6-0.9
0.6-0.8
W2
W1-W2
W1
R-W1
R
M-R
M
G-M
G

Fig.6.Comparisonofthermoluminescenceagesofquartzsandybarrier
andsedimentarycyclesinBinhThuanProvince,Vietnam[9].
The fifth sedimentary cycle was formed in
Late Holocene regression phase (Thai Binh
Formation in RRD and Can Gio Formation in
CCRD).Thiscycleisdominatedby sands,silts,
clay alluvial facies in upper part and silt, clay
deltaic plain, grey clay marshy and sand silt
clay deltaic front facies in
 lower part. Besides,
Late Holocene eolian sediments have been
formedbywindreworkingoldsandyformation.
In addition, the fifth cycle was also eolian
sedimentinsandybarsandsandydunesin CLRD.

4.Thermoluminescenceageofredsandycycles
inPhanThiet‐BinhThuanprovinces
The coastline of South
Central Vietnam is
dominated by extensive sandy coastal barrier
successions of Early Pleistocene, Middle‐Late
Pleistocene, LatePleistoceneandLatePleistocene
toEarly‐MiddleHoloceneandLateHolocene.
The first cycle: an angular tektite layer
coveredalternativeredandwhite‐yellowsand
barrier of Early Pleistocene. Probably, this red
sandsuccession
shouldhaveageolderthanthe
age of tektites (i.e. before 700 Ka) [1]. The
comparison of these successions with glacial
and interglacial in the world (Fig. 1)
correspondstointerglacialGunz‐Mindel.

Fig.7.Thesequenceofredsandandlightgreysand,
ChiCong,BinhThuanProvince,Vietnam[7].
The second cycle, composing of 2 rhythms,
was possibly equivalent to older grey‐white,
wellcementedsandbarrierofMiddlePleistocene
age (Q
1
2a
) (TL age of >204 Ka [1]). Moderate
cemented red sand barrier of Middle‐Late
Pleistocenearedominatedbyinnerbarriers.The
TranNghietal./VNUJournalofScience,EarthSciences23(2007)235‐243

240
sandy samples yielded an age of 103±11 Ka ,
101±17Ka[1],possiblyequivalenttostage5oflast
interglacialsensulatooftheOxygenIsotoperecord .
Thethirdcyclecomprisesbyaseriesofred
and yellow sand successions of barriers
dominated in coastal zone of South Central
Vietnam
from Phan Thiet to Tuy Phong. This
cycle over lies of Middle‐Late Pleistocene
sandy barrier successions the boundary
between second cycle is exposed and third
cycle in Hon Rom, Chi Cong, Suoi Tien and
Song Luy. The alternation of red sand and
yellowsandrhythmsrelatedtosealevelchange

andinfiltrationweatheringinlatePleistocene.
SampleVN31yieldedanage101±17Ka[1].
Sample VN31 yieldedan age of 101±17 Ka,
andVN32‐anageof108±49Ka(HonRom)[1].
ThisagerangebelongstoLatePleistocenecycle
whicharesuggestiveofdepositionduringstage
5(sensulato)oftheOxygenIsotoperecord.
Thefourthcyclecomposedoftworhythms:
an eolian red sand dunes of Late Pleistocene
(sampleat Phan Thiet airport yieldeda TL age
of 28±4 Ka) correlated with stage 2 and 3, and
white sand barriers oxygen isotope to be
equivalent with
 last glacial maximum (W

2
) of
Early‐MiddleHolocene.
The fifth sandy cycle reworked Holocene
quartzsandybarriertoformsand duneduring
3Katopresent.TheSouthCentralcoastalzone
betweenPhanThietandTuyPhongisdominated
on surface by light yellow active dune fields
due to reacting of wind,  possibly correlated

withHoloceneregressionandsealevelrise.
5. Cycles of coral reef in relation to sea level
change in coastal zone and shallow sea of
CentralVietnamarea
Coral reefs occur in 3 locations in shallow
seaofSouthCentralVietnam(Fig.8).
Middle‐LatePleistocenecoralreefs,which
were
calcified,occur in Hon Do‐Ninh Thuan.
This layer is covered by red sand. Late
Pleistocene coral reef terrace is distributed in
20‐25 m water depth. Middle Holocene coral
reef terraces are located in 1‐2 m water deep
yieldandageof5000yearBPbyC
14
dating.
Distribution of calcified coral reefs in
comparisonwithredsand(19Ka)showedthat:
this layer could have been formed in Middle‐
Late Pleistocene transgression and Vinh Phuc

transgression that created red sand and coral
reefin20‐25mwaterdepth.Theredsandlayer
coversthecoral.























Fig.8.DevelopmentperiodsofcoralinSouthCentral
area(HonGomPeninsula).
Thecoralterracein20‐25mwaterdepthwas
formedinFlandriantransgression.Thiswasthe

second sea level stands in Holocene and it is
correlative to ancient shorelines. The coral reef
at 1‐2m water depth, formed in Early‐Middle
Holocene,iscorrelatedwithwhitesandinCam

RanhandHonGom.
Q
2
1-2
Q
1
3b
20-25m
Q
2
2
Q
2
3
Q
2
2
Q
1
3b
m
v
Q
2
3

Red-Yellow
sand
White
sand
5
K
a
a
c
b

TranNghietal./VNUJournalofScience,EarthSciences23(2007)235‐243
241

Fig.9.LateritegravelinbottomsedimentinSW
EasternSea.

Fig.10.Foraminifera,diatomea,quaczitefragments
andfragmentsofdaciterockinbottomsedimentsin
SWofEasternSea.

Fig.11.WeatheringspottedclayinLatePleistocene
sedimentinSWofEasternSea.
6.Quaternaryshorelinesinbottomofcontin ental
shelfofVietnam
6.1.Ancientshorelines
The well‐sorted and well‐round ancient
sandy bars distributed parallel to modern
shoreline.
Well‐round laterite gravels are situated in

sea bottoms far from modern coastline. This
layer is covered by spotted clay la yer which
containedlaterite
curdles.
Concentrationofcoarse‐grainedterrigeneous
sediment and moderate to well‐roundness
bioclasts[9].
Location of ancient shoreline in continental
shelf[8]:
‐In30mwaterdepthcorrelatedwith(Q
2
1-2
).
‐In60mwaterdepthcorrelatedwith(Q
1
3b
‐Q
2
1
).
‐ In 100‐120 m water depth correlated with
Wurm
2
glaciation(Q
1
3b
).
‐ In 200‐300 m water depth correlated with
Wurm
1

glaciation(Q
1
3a
).
‐ In 400‐500 m water depth correlated with
Rissglaciation(Q
1
2b
).
‐ In 600‐700 m water depth correlated with
Mindelglaciation(Q
1
2a
).
‐In1000‐1500mwaterdepthcorrelatedwith
Gunzglaciation(Q
1
1
).
6.2. Relationship between marine terraces and
sedimentarycyclesintheseabottom
In Quaternary, appearance of fluvial and
marine terraces in mainland and continental
shelf are the results of uplift‐subsidence
movements and transgression‐regression
phases. Five ancient marine terraces on
mainland and 6 on continental shelf [9] from
Pleistocene
toHoloceneagescanbeidentified.
These terraces have symmetric relation, it

means that the oldest marine terrace on
mainlandisathighestelevation(highestpoint)
and the oldest marine terrace on continental
shelfisatlowestelevation(deepestpoint)(Fig.
12). The marine terraces on mainland and
continental shelf
of the same age were formed
in the same sedimentary cycle. These periods
extended from Pleistocene to Holocene. Thus,
sea level changes combined with uplift
activities on mainland and subsidence in sea
bottom characteristic marine terraces systems
hadproduced.
TranNghietal./VNUJournalofScience,EarthSciences23(2007)235‐243
242
Height
(m)
Terraces
Sea terraces on mainland Age of Continental shelf sediment
100
80
60
40
20
10
0
-50
-100
-200
-400

-500
-600
-2000
-2500
Qb
I
VI
V
V
IV
III
II
I
I
II
III
IV
V
VI
Qa
I
Qa
I
Qa
II
Qa
II
Q-Q a
II III
1

Qa
III
1
Q
III
2
Q
III
2
Q-Q
III IV
21
Q
IV
3
Q
IV
3
Q
IV
3
Q
IV
2
Qb
II-III
1
Qb
III
2

Q
I
Q
III
Q
IIIB
2
Q
IIIA
2
Q
IIIb
2
Q
II
1
Q
I
1
Q
IV
2
Q
IV
3
Q
IV
3
Q-Q
III IV

21
Q-Q
III IV
21
Q
IIIa
1
1
120
7
7
6
6
5
5
4
4
3
3
22
2
1
1
Glacier phases
Wurm
(W)
Riss
(R)
Mindel
(M)

Gunz
(G)
Dunai
(D)

Fig.12.RelationshipbetweenseaterracesandPliocene‐Quaternarysedimentarycycles
incontinentalshelfofVietnam[10].
7.Conclusions
In Quaternary, cycles of sea level change
and tectonic movement cycles are the main
reasons, which  create Red River Delta, Cuu
LongRiverDeltaandCentralplain.Thereare5
sedimentarycyclescorrespondingto5cyclesof
sea level change in Red River Delta, Cuu Long
River Delta, and
 Central plain. In Central
littoral plain, the relationship between
sedimentary cycles and sea level change is
characterized by 5 sandy cycles and
distributionofcoralterracesinshallowsea.
Thereare5generationsofancientshoreline
zones,whichcanbecorrelatedwithglacialand
interglacial phases in Vietnamese continental
shelf:
at30mwaterdepthcorrelatedwithQ
2
1-2
;
at60mwaterdepthcorrelatedwithQ
1

3b
‐Q
2
1
;at
100‐120 m water depth correlated with Wurm
2

glaciation Q
1
3b
; at 200‐300 m water depth
correlatedwithWurm
1
glaciation(Q
1
3a
);at400‐
500 m water depth correlated with Riss
glaciation Q
1
2b
; at 600‐700 m water depth
correlated with Mindel glaciation Q
1
2a
; and at
1000‐1500 mwaterdepthcorrelatedwithGunz
glaciationQ
1

1
.Theseanc ientshorel inescorrelated
with marine terraces and 6 sedimentary cycles
incontinentalshelf.
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