Disaster Advances
Vol. 5 (4) October 2012
Depositional slope break in shallow marine shelf setting
and its control on regional forced regressive wedge
systems tract
Liu Hao1*, WangYingmin2 and Xin Renchen1
1. School of Marine Sciences, China University of Geosciences, Beijing, P. R. CHINA
2. Department of Geosciences, China University of Petroleum, Beijing, P. R. CHINA
*[email protected]
assemblage is formed and stratigraphic-lithologic
hydrocarbon accumulations usually occur in these
areas.
Abstract
During the deposition of the Miocene Zhujiang
Formation, the HZ Sag in the Pearl River Mouth
Basin, South China Sea, was a stably deposited shelf
setting. A large-scale paleo-Pearl River water system
was developed in the western part of the study area
and provided abundant terrestrial deposits for the
large-scale Pearl River delta. Depositional slope
breaks with obviously varying gradients were formed
along the delta front - prodelta belt due to their
apparently differential deposition in these areas. The
development of slope break in 3-D space is
characterized by its inheritance, intermittent nature
and cyclicity of time-spatial shifting. Large-scale
depositional slope breaks mainly occurred in the
Zhujiang Formation Middle Member. A case study on
sequence PSQ6 has been carried out in this study.
Keywords: The Pearl River Mouth Basin, the Zhujiang
Formation, Depositional slope break, Regressive wedge
systems tract.
Introduction
Theories of classical sequence stratigraphy indicate that
lowstand systems tract is defined as the special product of
type-I sequence with a shelf slope break and is mainly
developed on the slope and basin bottom under the shelf
slope break27-29. Whether other kind of deposits can
develop in the relatively gentle shelf setting besides the
incised-valley filling deposits which are formed in low
water level period?
The concept of slope which was first and most commonly
used in geology is generally referred to shelf slope, namely
as slope area of shelf edge, while, slope break is usually
defined as shelf break i.e. the turning position from a gentle
topography to a steep one of the outer shelf and shelf slope.
The international hotspots, deep water depositional system,
is the depositional system related with shelf slope2,3,15-18,2124,26,35,38
. In broad sense, sudden change of topography is
very common whether in marine basins or in continental
basins, whether in the interior of a basin or in its erosional
area. Slope breaks with different scales can occur anywhere
if only the topographic gradient changes obviously. Is it
possible that regional FRWST can be formed in areas near
these slope breaks with different scales?
The depositional slope break of sequence PSQ6 is
characterized by a certain developing scale of about 4
Km slope width, 20-60 m height difference and 80 Km
transverse distribution range. Depositional slope
breaks were mainly developed during the ending time
of the depositional period of highstand systems tract
delta of underlying sequence. A regional “ditchtrough” system was formed along the area between
depositional slope break and carbonate buildup in the
east of prodeltaic subfacies, thus provided a favorable
paleogeomorphic setting for the deposition and
preservation of PSQ6 forced regressive wedge systems
tract(FRWST) and furthermore controlled the
development of regional forced regressive wedge in
shelf environment.
Many researchers have proposed the concept of lacustrine
basin slope break through studies of continental lacustrine
basins4,6,8-11,31-35. Fan et al4 considered that the multi-grade
fracture slope break belt of the Dongying Formation in
Shenghai area, Bohai Bay Basin in China, has an obvious
control on the incised valley sandbodies. Wang et al32-34
discovered that slope breaks obviously occurred in the
Jurassic depressional lacustrine basins by analyses of the
Juggar Basin and the Songliao Basin during 2002-2004 and
divided slope breaks into structure slope break, erosional
slope break and depositional slope break according to their
origins. Slope break is also divided into aquatic and
subaqueous ones and the latter controls the development of
lowstand systems tract. Liu et al8-10,11 proposed that multigrade slope break had an important control on the
It is quite different from the incised valley pattern
which is developed above the shelf slope break and
was described by Vail’s classical sequence
stratigraphy. The forced regressive sandbodies are
easily formed due to the “ditch-trough”
paleogeomorphic setting in shelf environment. The
progradational sandbodies directly cover the shallow
marine mudstones of the underlying sequence
highstand systems tract and are overlaid with the
dark-color mudstones of transgressive and highstand
systems tracts, thus a favorable source- reservoir- seal
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development of sequence and depositional systems
according to the characteristics of the Juggar Depressional
Basin, China.
The Pearl River Mouth Basin is the Cenozoic depositional
basin and mainly comprised the Paleocene Shenhu
Formation, the Eocene Wenchang Formation, the
Oligocene Enping Formation, the Miocene Zhuhai
Formation, Zhujiang Formation, Hanjiang Formation,
Yuehai Formation and the Pliocene Wanshan Formation.
During the early period (the deposition of the Shenhu
Formation-Enping Formation), the basin was in a rifted
setting. In the middle-late period (from the deposition of
the Zhuhai Formation to the present), it was a stably
deposited depression setting and the Zhujiang Formation
was dominated by a depressional shallow marine shelf
environment.
Geologic background
The HZ Sag is located in the Zhuyi Depression of the Pearl
River Mouth Basin of the northern South China Sea. To the
north, it is adjacent to the northern faulted-ladder zone, to
the south, it reaches the Dongsha Palaeo-high of the Central
Uplift Zone and respectively coexists with the Huilu
Convex and the Xijiang Sag in the east and west. It
stretches in a NE direction and is the important area for the
formation, development and evolution of the Neogene
palaeo-Zhujiang delta-shore depositional system (Fig.1).
Fig. 1: Location of the HZ sag in the pearl River Mouth Basin. B shows 3-D seismic survey range of the HZ Sag
and the structural characteristic of the sequence boundary SB6 in the Zhujiang Formation Middle Member
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slope breaks of different lines probably develop are
connected and the planar distribution is established; Finally
the planar association is projected on the isoline maps of
thickness and regional revisions have been completed.
Sequence stratigraphy
Studies of basin sequence stratigraphy began from the late
1980s.The earliest sequence stratigraphic study results of
the Pearl River Mouth Basin were shown in papers of Xu39,
Yang40 and Qin et al20. On the basis of seismic data, drilling
hole, well logging and micro-palaeontology data, they
established the sea-level changing curve of the Pearl River
Mouth Basin and correlated with the global sea-level
changing curve proposed by Haq et al5. Their studies
indicated that 4 second-order sequences and 23 third-order
sequences were developed in the Pearl River Mouth Basin
from 36 Ma to the present which can be correlated with
EXXON’s cycle curve.
Depositional slope break developed during the
deposition of the Zhujiang Formation: During the
Neogene time, depositional systems including delta, shore
deposit and shelf were developed in the Huizhou Sag of the
Pearl River Mouth Basin. A great deal of studies indicates
that depositional slope break obviously occurs in the main
parts of delta front (Fig.3). These slope breaks mainly
occurred adjacent to A4-A9 well area in the southern HZ
Sag and distributed in NE-SW direction. They were
developed with quite different scales. The slope break
which was developed during the deposition of PSQ6 had a
larger scale with a transverse expanding distance about 80
Km, a height differential of 20-40 Km and a width about 4
Km (Fig.4).
In contrast with EXXON’s map, the first-order sea level
cycle of the Pearl River Mouth Basin was characterized by
a large-scale transgression and the superimposing pattern of
its third-order sequences were obviously of regional
characteristics40. Wang31 divided the Miocene into 9 thirdorder sequences according to data of 5 drilling holes and
the sequence boundaries are respectively SB23, SB20,
SB18, SB16.5, SB15.7, SB14.5, SB13.0, SB9.3, SB6.3 and
SB5.5. The geologic periods of the boundaries are different
from those identified by the pre-researchers. Shi et al25
divided the Zhujiang Formation of the eastern Pearl River
Mouth Basin into 2 third-order sequences and 5 systems
tracts whose sequence boundaries are respectively SB21,
SB17.5 and Sb16.5.
Origins for depositional slope break: Different
sedimentary rates in different areas lead to the sudden
change of stratigraphic gradient and thus lead to the
formation of depositional slope break. In the jointing area
of delta plain and delta front, depositional slope break
which is developed in late period is easily to be formed and
corresponds to the top part of progradation reflection
(Fig.5). Before the deposition of the Zhujiang Formation,
due to the formation and large-scale elevation of the
Dongsha Uplift, from east to west, a palaeogeographic
setting was formed in which uplift occurred together with
sag. Carbonate rocks were widely developed in the
uplifting areas, while delta facies was developed in the
sagging belt in western area due to the occurrence of
abundant terrestrial materials provided by the paleoZhujiang currents.
Through strict seismic-drilling well combination, based on
the viewpoint of emphasizing objective physical
relationship by Mitchum et al15, Van Wagoner et al30,
totally 13 fourth-order sequence boundaries, 5 sequence
boundaries and 2 structural sequence boundaries have been
recognized. Thus, 1 structural sequence, 4 sequences and
12 fourth-order sequences were divided (Fig.2). The
sequence PSQ6 developed in the middle member of the
Zhujiang Formation includes highstand, transgressive and
forecd regressive systems tracts.
A limited “ditch-trough” with a NE-SW distribution
direction occurred in area between delta sedimentary
system and carbonate uplifting area. The slope at the west
wane of the “ditch-trough” was formed due to different
depositional rates of deltas in early period (Fig.6 and
Fig.7). This palaeogeomorphology setting continuously
occurred during the deposition of PSQ6-PSQ9. The
palaeogeomorphology setting during the deposition of
PSQ4-PSQ5 was similar as the former one, while the
developing scale of delta was smaller, thus it is not the
emphasis of this study.
Characteristics of depositional slope breaks
which were developed during the deposition of
the Zhujiang Formation Middle Member
Identification of slope break: Slope break reflects a
sudden change of time T0 on a seismic profile and a sudden
change of stratigraphic thickness on a geologic profile. On
the isoline maps of strata thickness, slope break
corresponds to the area where isolines concentrate and the
stratigraphic thickness suddenly increases from slope break
to the toe of slope foot11. The identification of slope break
in this study mainly focused on stratigraphic correlation by
seismic data, drilling and logging data as well as sequence
isoline maps of thickness etc.
Due to the gradual withering of eastern uplift during the
depositional period from PSQ10 to PSQ17 and continuous
filling of terrestrial materials of later period in the lying
areas, the palaeotopography gradually became gentle in
these periods. Although the Paleo-Zhujiang Delta was
developed well, the slope break was characterized by a
smaller scale and it had an unobvious control on low water
level period deposit on the shelf.
Analyses have been carried out on changes of thickness and
reflectance texture of seismic profile, combined with
geologic analyses of drilling holes. First, the identification
of slope break on the line is made; Then the position where
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Fig.2: The sequence stratigraphic framework of the Lower Miocene in the HZ Sag. SQ-Sequence,
PSQ-4th-order Sequence, TST-Tansgressive systems tract, HST-Highstand systems tract, FRWST-Forced regressive
wedge systems tract
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Fig.3: The Seismic reflection characteristics of the depositional slope break developed at the bottom of sequence
PSQ6. A is the original seismic profile, B is the interpretation result. A large-scale delta characterized by the
reflectance is developed below the main body of the depositional slope break.
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Fig. 4: Isopach map of the FRWST and TST of sequence PSQ6. Typical depositional slope breaks are developed along
wells A4-A9 and the strata thicknesses up and below the slope break are obviously different.
Fig.5 Relationship between the delta deposition and the slope breaks. A is the original seismic profile, B is the
interpretation result of the depositional slope break and ci s the development pattern of the slope break due to the
differential deposition of delta
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Fig.6: Correlation of the drilling holes which shows the relationship between delta deposition and depositional slope
break
Fig. 7 : The seismic response of he “ditch-valley” setting which occurred in the area between the palaeo-Zhujiang
delta and the Dongsha Carbonate buildup up and below the sequence boundary SB6.
Un-continuous development of slope break: Uncontinuous development of slope break refers to that slope
break controlled by the same origin mechanism is not
continuously developed at the definite geographic location
and in certain periods, that is, the formation and
disappearance of slope break happened alternately.
Depositional slope breaks in the HZ Sag are characterized
by their obvious un-continuous development. In ascending
order, during the deposition of PSQ4-PSQ12, slope break
was well developed, while during the deposition of PSQ13,
no slope break developed and from PSQ14 to PSQ18, slope
break developed again, while disappeared above PSQ18.
The un-continuous development of depositional slope break
indicates the difference of sediment material supply and sea
level change (Fig.8).
Evolution features of slope break
Depositional slope break is continuously developed and
inherits features of slope break in earlier period: In the
southwestern area of the basin, from the deposition of the
Zhujiang Formation to the deposition of the top of Yuehai
Formation, delta facies was well developed. The
continuous sources provided by the paleo-Zhujiang currents
formed deltas of multi-stages and prepared conditions for
development of depositional slope break. Along delta front
belt, i.e. area adjacent to A4 well area, during the
deposition from PSQ4 to PSQ12, slope break was
developed and inherited features of slope break in earlier
period on all the sequence boundaries except that
depositional slope break was not obviously developed on
SB13(Fig. 8).
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indicates instability of depositional shoreline and is formed
due to the comprehensive influence of sea level change,
regional tectonic movements, sediment material supply and
climate. 5 shifting cycles exist from SB4 to SB18 which
respectively reflect the 5 times of large-scale sea level rise
and fall cycles (Fig.9) and correspond to the cycle division
of sequence sets (Fig.2).
Cyclic nature of time-spatial shifting: Time-spatial
shifting refers to the round shifting of slope break of the
same kind in offshore-onshore direction at the same
geographic location in different periods. Slope breaks in the
southern HZ Sag shifted with an obvious regularity in
different periods and the shifting cycles formed in different
periods constitute a shifting cycle. Shifting of slope break
Fig.8: The inheritance development feature of depositional slope breaks. A is the practical seismic profile, B is the
interpretation results of seismic reflectance textures and depositional slope breaks.
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Fig. 9: The time-space shifting regularity of the depositional slope breaks, the distribution of the slope breaks is
shown in fig.8 and there are totally 5 shifting cycles during the deposition of SB4-SB18
Cycle 1 PSQ4-PSQ7: Slope break began its development
during the early depositional period of PSQ4 and shifted
from onshore area towards offshore area. In the early
depositional period of PSQ7 (SB7), the development of
slope break ended.
PSQ17. SB16 is a transitional point in this cycle.
The slope break on SB7 shifted the longest distance
towards the offshore area. During the deposition of PSQ7,
the slope break shifted towards the onshore area, thus there
were two transitional points i.e. SB4 and SB7 in this cycle.
The relationship between depositional slope
break and regional low water level period
deposit- Taking PSQ6 as an example
Cycle 5 PSQ17-: Slope break is not developed in strata
above sequence boundary SB18. This cycle is an
incomplete one.
Characteristics of low water level period deposit:
Studies of sequence stratigraphy indicate that PSQ6 has an
obvious texture of division into three parts and is
characterized by its low water level period deposit. Initial
flooding surface mainly occurs at the top of the negative
cycle which is dominated by accumulation-transgression
deposition on drilling well profile and its mudstone
thickness is much smaller than that of the condensed
member which is formed in the maximum flooding surface
period (Fig.10). The interpretation about seismic data
indicates that distribution of low water level period deposit
is locally distributed in A4- A8 well area and area west of
the top of limestones. It has a texture of forereflectancedune-shape reflectance (Fig.3, Fig.7). Identification of
sandbodies shows that 2 sets of sand intervals constitute the
low water level period deposit (Fig.11).
Cycle 2 PSQ8-PSQ10: Slope break shifted from onshore
area towards offshore area since the early depositional
period of PSQ8. In the late depositional period of PSQ10,
slope break shifted backwards to the onshore area. The
transitional point of this cycle is at SB10
Cycle 3 PSQ11-PSQ13: Depositional slope break shifted
towards the offshore area after PSQ10 ended its deposition
and the development of slope break ended till the early
depositional period of PSQ13. SB13 is an important
transitional point in this cycle.
Cycle 4 PSQ14-PSQ16: Slope break shifted from the
onshore area towards offshore area again until the late
depositional period of PSQ16. Slope break shifted back to
the onshore area during the early depositional period of
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Fig. 10: Correlation of the drilling holes which shows the control of depositional slope breaks on FRWST
Fig. 11: Recognition of the LST6 sandbodies 2 sets of sandbodies are developed in the lowstand systems tract, A is the
wave impedance inversion section, the yellow-red area represents the high value of wave impedance, which reflects
the developing characteristics of sandbodies. B is the interpretation result of lowstand systems tract sandbodies.
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Data of drilling holes indicate that sandbodies are generally
over 2m thick and the thickest sandbody (22m) occurs in
Well A4 area. Sand-containing ratio is generally over 2%
and the Well A4 area has the largest value of 40%.
Sedimentary type is simple and shallow marine and shelf
sand facies are developed just in southern area (Fig.12).
Fig.12: Comprehensive column of sequence-sedimentary facies of the PSQ6 FRWST (Data from Well A10), STSystemstract, SQ-Sequence, MF-Microfacies, SF-Subfaies
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Origins of low water level period deposit: Regression
happens in two styles:1) When sediment supply exceeds the
increase of accommodation, shoreline shifts towards the
ocean and regression occurs even if the sea level rises
which is named as the normal regression; 2) During the sea
level falling period, the increasing rate of accommodation
is a negative one which leads to the sediment supply rate as
always larger than the increasing rate of accommodation,
regression occurs even without sediment supply and with
sediment supply, regression surely occurs. This kind of
regression is called the forced regression1,13,19,36,37.
characterized by a typical progradational reflection (Fig.3,
Fig.7), which is separated from the highstand deposit by a
sediment surpassing belt (Fig. 13). Isolated sandbodies are
distributed in a strip-banded shape. Sedimentary facies
research results indicate that this set of sandbody is the
shallow marine shelf deposit far away from the provenance
area. Rational interpretation can be obtained for this
isolatedly distributed sandbody on the shelf according to
force regressive origin theory. Obvious stratigraphic
erosion occurs at the upper strata of slope break and it is
usually developed as the incised valley25 (Fig.14).If the
angle between the slope belt and the upper slope toe is
considered as the secondary shoreline on the shelf which is
just consistent with the force regression concept proposed
by Posamentier et al19, this kind of lowstand sandbody is
dominated by forced regressive sandbody. “Forced
regression” concept is widely applied to continental
lacustrine basin with slope break topography and it is
considered the forced falling of lake level has a similar
influence on the formation of lowstand systems tract as the
marine strata7,12.
A series of progradational wedges formed by forced
regression is called forced regressive wedge systems tract
(FRWST). Along the slope margin, none bypassing
sediments are transported to the basin floor during the
relative sea level falling period, then sediments are
probably deposited as a set of gradual falling programdational wedge36-37.
The low water level period deposit of PSQ6 is
Fig.13: The planar distribution of the maximum amplitude of wave impedance inversion up 16 ms along the sequence
boundary SB6, the yellow-red area represents the developing characteristics of sandbodies.
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Fig. 14: The reservoir sandbody distribution during the deposition of K22 above the sequence boundary 17.5 Ma25
The occurrence of depositional slope break provides the
palaeotopography setting for the development of FRWST,
at the same time, the carbonate platform becomes a good
shelter. While the HZ Sag is located on the continental
shelf, when sea level falls, the accommodation above the
continental shelf decreases and sediments are advanced
towards the ocean; when sea level falls below the shelf
slope break, most areas of the shelf experience erosion or
sediment bypassing. The occurrence of an obvious “ditchtrough”lowlying area provides some space for the
deposition and preservation of sediments (Fig.7). There is
obvious difference of accommodation above and below the
depositional slope break during the lowstand period of sea
level falling. The accommodation above the slope is
smaller, sediments influenced by various ocean fluids
experience some erosion and the eroded sediments are
transported the lowlying area with larger accommodation
and apparent progradational wedge is developed. This
“ditch-trough” palaeotopography provides better conditions
for the development and preservation of FRWST.
Depositional slope break and preservation of forced
regressive systems tract: According to the relationship
between the recognized depositional slope break and the
distribution area of FRWST, FRWST is generally located in
the narrow lowlying area between the west of depositional
slope break and the Dongsha Uplift which is closely
adjacent to the depositional slope break and the matching
relationship is good (Fig.6, Fig.7).
Generally, the low water level period deposit, besides the
incised valley formed by fluvial erosion on the continental
shelf, is more of progradational wedge mainly deposited on
the continental shelf slope and its lower part, while the
progradational wedge cannot be preserved on the
continental shelf. The development and preservation of
FRWST in the HZ area are attributed to the depositional
slope break belt formed by the constructive delta of
highstand systems tract in early period and the carbonate
deposit on the Dongsha Uplift in the eastern area. The
bioreef of the Dongsha Uplift is the product of marine
setting which is far away from the provenance area and the
water is clear and transparent. The bioreef belongs to
platform margin bioreef of clear water-saline water reefforming pattern. The area and thickness of single bioreef
are small, with diverse types and wide distribution which
indicates that deposition of the PSQ5 high stand delta has
little influence on bioreef’s growth. Water between the
delta and carbonate platform is relatively deep, the
accommodation is large, which leads to the formation of a
“ditch-trough” palaeotopography in this area.
Hydrocarbon significance of depositional slope
break controlling low water level period deposit
Theoretically, the progradational sandbodies formed by
forced current regression can directly cover the shallow
marine mudstones of the underlying highstand systems
tract and are covered by mudstones of transgressive and
high stand systems tracts, thus a profitable sourcereservoir-cap rock association is formed. Lithologic
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Vol. 5 (4) October 2012
hydrocarbon accumulations with large areas are easily to be
formed in this setting.
Conclusion
1) Delta facies was widely developed during the deposition
of the Zhujiang Formation in the HZ Sag. Due to the
differential subsidence in delta front - prodelta subfacies,
obvious depositional slope of multi-stage was developed in
shelf setting.
Practical studies focusing on amplitude picking-up, wave
impedance inversion etc. and FRWST sandbodies are
described in details. The studies show that sandbodies of
PSQ6 low water level period deposit are well developed
and are isolatedly distributed as a strip-belt shape (Fig.13).
The distribution of sandbodies matches well with the
structural setting and many stratigraphic-lithologic traps
can be formed (Fig.15). These sandbodies of forced low
water level period are located far from the provenance area.
Below the sandbodies, HST5 prodelta mudstones or shelf
mudstones are widely deposited, above them, mudstones of
transgressive systems tract are developed, which provide
favorable sealing conditions for traps. Oilfield exploration
and oil and gas show indicate that the two sets of
sandbodies of PSQ6 low water level period deposit belong
to the main petroliferous interval K22 in the study area25
which constitutes high-quality reservoirs. Results of
attribute-picking-up and wave impedance inversion also
indicate that sandbodies are well developed. Otherwise, the
low water level period deposit sandbodies are distributed
adjacent to the faults in the north and petroleum in the
northern hydrocarbon-generating sag can be migrated to the
sandbodies through these faults (Fig.15). Sandbodies of
forced low water level period which are controlled by
depositional slope break play an important role in
exploration of subtle petroleum reservoirs.
2) The development of the depositional slope break is
characterized
by
its
inheritance,
un-continuous
development and cycle nature of time-spatial shifting.
These features are related with sediment supply, sea level
rise and fall and the palaeogeomorphologic characteristics
in the earlier periods.
3) Not all the depositional slope breaks can control the
formation of the low water level period deposit. It is the
special
palaeogeomorphology
that
controls
the
development of the regional low water level period deposit
of sequences developed in later period. The constructive
delta developed during the deposition of the earlier
highstand systems tract accumulated towards the basin and
the “ditch-trough” framework formed in areas in the west
of the carbonate platform constituted the favorable
palaeogeomorphologic conditions. This special palaeogeomorphologic setting is different from the typical shelf
incised valley pattern proposed by Vail et al27-29, thus has a
different controlling influence on low water level period
deposit.
Fig. 15: The matching relationship relationship between FRWST6 sandbodies and the structural forms
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Vol. 5 (4) October 2012
down-warped lacustrine basin in western-margin area, Junggar
Basin, northwestern China, Marine and Petroleum Geology, 23(910), 913-930 (2006)
4) There is a good coupling relationship between
depositional slope break and low water level period
deposit. Due to the existence of depositional slope break,
during sea level falling, most low water level period
deposits are of forced regression origin.
12. Liu Z. J., Cheng R. H. and Yi H. Y., The conception,
development and dispute of sequence stratigraphy, Global
Geology, 13(3), 56-68 (1994)
5) The demonstration of low water level period sandbodies
indicates that transgressive sandbodies formed by forced
regression can form better subtle traps with favorable
source-reservoir-cap rock conditions.
13. Mei M. X. and Yang X. D., Forced regression and forced
regressive wedge system tract: revisionon traditional exxonmodel
of sequence stratigraphy, Geological Science and Technology
Information, 19(2), 17-21 (2000)
Acknowledgement
14. Mienert J., Editorial-COSTA-continental slope stability:
major aimsand topics, Marine Geology, 213(1-4), 1-7 (2004)
The paper is benefited by funds from National Natural
Science Foundation of China (NSFC) programs and
National Basic Research Program of China (also called 973
Program), the approved numbers of which are, respectively,
40572067 and 2007CB411703.
15. Mitchum R. M. et al, Recognizing sequences and systems
tracts from well logs, seismic data and biostratigraphy: examples
from the Late Cenozoic of the Gulf of Mexico, Siliciclastic
sequence stratigraphy: recent developments and applications, 70
(3), 155-170 (1993)
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