Sedimentological sequence and depositional evolutionary model of Lower Triassic carbonate

China?Geology?3?(2019)?301?314

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China?Geology

Journal?homepage:?http://chinageology.cgs.cn

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Sedimentological?sequence?and?depositional?evolutionary?model?of?Lower?Triassiccarbonate?rocks?in?the?South?Yellow?Sea?Basin

Yu-xi?Zhanga,?b,?Jian-wen?Chenb,*,?Jiang-yu?Zhoua,?Yong?Yuanb

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a

?Faculty of Earth Resource, China University of Geosciences, Wuhan 430074, China

?Qingdao Institute of Marine Geology, China Geological Survey, Ministry of Natural Resources, Qingdao 266071, China

b

A??R??T??I??C??L??E??????I??N??F??O

A??B??S??T??R??A??C??T

Article history:

Received?8?January?2019

Received?in?revised?form?27?July?2019Accepted?7?August?2019

Available?online?20?September?2019

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Keywords:Lower?Triassic

Sequence?stratigraphySea-level?changeCarbonate?rocks

Marine?geological?survey?engineeringYellow?SeaChina

Based?on?well?logging?and?seismic?data,?combined?with?a?comparative?analysis?of?drilling?data?in?theLower?Yangtze?region,?the?sequence?stratigraphic?framework?of?the?Qinglong?Formation?was?establishedand?divided?into?four?third-order?sequences.?Each?sequence?is?mainly?composed?of?the?transgress?systemtract?(TST)?and?the?high-stand?system?tract?(HST).?According?to?the?lithology,?logging?curve?and?seismicreflection?structure,?the?sedimentary?filling?characteristics?and?evolution?law?for?the?sequence?are?analyzed.The?results?show?that?each?sequence?is?dominated?by?a?half-cycle?decline?of?sea?level,?and?the?rise-fall?ofsea?level?controls?the?distribution?and?evolution?of?sedimentary?systems?within?the?sequence.?During?therelative?sea-level?rise,?sedimentation?rates?slow?down?and?muddy?sediments?are?developed.?Thecharacteristics?of?condensing?intervals?on?the?flooding?surface?are?very?obvious,?and?continental?shelf?andopen?platform?deposition?are?mainly?developed.?During?the?relative?decline?of?sea?level,?the?thickness?ofsediments?increased.?The?main?developments?were?restricted?platform?and?platform?shoal?environment,and?locally?developed?evaporation?platform?environment.

?2019?China?Geology?Editorial?Office.

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1. Introduction

In?the?early?1990s,?Carbonate?sequence?stratigraphy?wassignificantly?developed,?in?establishing?the?basic?theory?ofcarbonate?sequence?stratigraphy?(Gnaccolini?M?and?Jadoul?F,1990;?Mitchum?RMJ?and?Wagoner?JCV,?1991;?Schlager?W,1991;?Ogg?JG?and?Steiner?MB,?1991;?Hunt?D?and?MauriceME,?1992;?Oloriz?F?et?al.,?1993)?and?analyzing?the?differentsequence?patterns?of?carbonate?strata?(Burchette?TP?et?al.,1990;?Gardulski?AF?et?al.,?1991;?Vander?ZCJ?and?Spaak?P,1992;?Maynard?JR,?1992;?Loucks?RG?and?Sarg?JF,?1995;?SargJF,?2001;?Catuneanu?O?et?al.,?2009).?After?years?of?continuousresearch?(Gattolin?G?et?al.,?2015;?Gutierrez?PHC?et?al.,?2017;Mei?MX?and?Tucker?ME,?2013;?Hashmie?A?et?al.,?2016;?YiHS?et?al.,?2011;?Li?SH?et?al.,?2017;?Jamaludin?SNF?et?al.,2018)?and?have?been?widely?used?in?the?field?of?oil?and?gasexploration?(Ma?YS?et?al.,?2008;?Mei?MX,?2015;?Cui?XH?etal.,?2010;?Du?W?et?al.,?2013;?Liu?D?et?al.,?2014;?Chang?JH?etal.,?2017;?Beigi?M?et?al.,?2017;?Zecchin?M?et?al.,?2017).?In

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*?Corresponding?author:?E-mail address:?jwchen2012@126.com?(Jian-wen?Chen).

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doi:10.31035/cg2018113

2096-5192/??2019?China?Geology?Editorial?Office.

recent?years,?studies?of?carbonate?sedimentary?filling?withinthe?sequence?framework?has?attracted?much?attention?in?oiland?gas?exploration?(Lin?CS?et?al.,?2013;?Zhang?JL,?2017;Tavakoli?A,?2017).

The?South?Yellow?Sea?Basin?(SYSB)?is?a?multi-cyclesuperimposed?basin,?which?is?located?at?the?basement?of?theSinian?metamorphic?rocks?up?of?the?Lower?Yangtze?Platform(Fig.?1).?The?exploration?of?the?basin?is?relatively?low.?Inrecent?years,?more?research?has?been?done?on?the?marineMesozoic-Paleozoic?strata.?The?study?found?the?LowerTriassic?carbonate?strata?in?the?SYSB?to?be?well?developedand?relatively?stable?in?structure?(Chen?JW?et?al.,?2016,?ZhangYG?et?al.,?2014).?Although?certain?exploration?achievementshave?been?made,?no?significant?industrial?oil?and?gasdiscoveries?have?been?obtained?so?far.

Many?scholars?have?pointed?out?that?the?formation?andevolution?of?the?sequence?is?the?result?of?sea?level?changes,regional?tectonic?changes,?and?sedimentary?filling?rates?(SargJF,?2001,?Loucks?RG?and?Sarg?JF,?1995).?For?marinecarbonates,?the?main?factors?affecting?the?sequence?depositionare?sea?level?change?and?basement?settlement?(Zhao?ZJ,2015).?In?the?early?Triassic,?the?settlement?of?the?SYSB?wasrelatively?stable.?It?can?be?seen?that?the?development?of?the