重矿物分析识别浊积体的沉积作用——日本中部Niigata孤后含油盆地新第三纪烛积砂岩实例研究(英文)

第7卷第3期2000年9月地学前缘(中国地质大学，北京)EarthScienceFrontiers(ChinaUniversity01Geoscienc圃.Beiji咆)Vol.7No.3Sept.20∞NEWAPPLICATIONOFHEAVYMINERALANALYSISTODISCLOSETHESEDIMENTARYPROCESSOFEACHTURBIDITESANDSTONEBODYANDTOIDENTIFYINDIVIDUALTURBIDITESANDSTONEBODIES-一-CASESTUDIESONNEOGENETURBIDITESANDSTONESINTHENIIGATABACKARCOILBASIN,CENTRALJAPANShuichiTokuhashi1,ChristopherM.Agyi鸣j2(1.GeologicalSurueyofJa阳n，1-1-3Hi.庐山，Tsuku缸，1，缸raki305-8567,Ja如川2.UniversityofBuea,P.O.Box63,Buea,SouthWestProvince,Cam旷∞n)重矿物分析识别浊积体的沉积作用一一日本中部Niigata孤后含油盆地新第三纪烛积砂岩实例研究摘要:沉积于中中新世到上新世的浊积砂体是第三纪Ni也'ata弧后盆地的主要油气储层之，该盆地是日本列岛最富产石油的盆地。我们对这些浊积砂体的重矿物进行了详细和系统地分析。首先，作者展示了将重矿物分析和沉积作用分析相结合，从而得出有关沉积过程的全新观点的实例。沿着位于盆地东缘的上新世早期的浊积砂岩体的垂向和横向取样分析表明，砂体东半部重矿物的成分和百半部重矿物的成分不同。重矿物和沉积分析结果表明，发育在东半部的浅海陆架浊积砂岩和发育在西半部的深海水下浊积体在上新世早期是相互叠置的。其次，作者检验了用重矿物成分作为指标来表征某个特定浊积体的有效性。为此目的特选重位于Ni­地ata盆地中部的许多浊积砂岩分析研究，得出以下结论。(1)基于主要重矿物，比如蛋白石、普通角闪石、紫苏辉石和普通辉石的定量综合分析，至少可将研究区的浊积砂岩划分为6种类型;(2)-个组或段的浊积砂岩包括-种类型或紧密相关的两种类型;(3)研究区不同的组或段通常由不同的重矿物组成构成，不同的物源戎相同物源下不同的地质事件(例如火山活动开始期)可能是这种差异的原因。重矿物分析不仅可作为有价值的常规手段估计物源方向，而且可同其他的沉积资料结合来解析况积过程，估计几个相邻砂体的原始联系，进而预测地表或地下浊积砂体的三维空间展布。关键词z重矿物分析;现积过程;i.虫积体;新第三纪;弧后盆地;日本中部中图分类号:P512.2õ自79文献标识码:A文章编号:1ω5-2321(2刷103-0177-25收稿日期:2阳-04-26作警简介:Sh山hiTohuhashi.男.博士，日本地质调查局矿物与燃料资源部资深地质学家。一171一id;iijis&LJiijJ·-雹.1CiI鹏雹细菌撞撞四.....他学雷f喝醉2000.7(3)oIntroductionAstheoffshoreexplorationactivityofoilandgasbe∞mesdeeperanddeeper,theroleofturbiditesandstonereservoirsbe∞mes削山山hMFM·叶1胁町叶时1阴阳山J叶卧ιmmJmbMt-U}四日ωMJth旺，m忧町bm时mm·阳山叩爪ut咆币'KJMm叩vmhmmo阻WMmmuud阴阳JmfuwtM-Mdmnep削旬，叫问dMU优tM:四川UntmMJmωgra与斗UJmmhuMh川江-m叫ETmr由m叫阳市旷川川配川江mdMCwmmh二世…tmdJ创立且他mMM阴阳山…牛叩门口可………山中……r川…口吼叫仙也脱MY叫出叫fwM阳mmm阳m阳·吨a民nuJ叭E-可EHMndm∞制优Td'hr-mhlmh1叩，叫52叫nueh山MmmJωaJMrJm阳M·剧创dM几a'由口oh-2μ呻mmωwmom-mmm臼UTIm--ymg向伽叫mBMetae-m由甜Em阴山阴MKd队，Rma岱巾mumwmhωml阳mmJ时川JT阳阳丸'川出mh川阳山州出叭Mmm…h川hm阳山dMmp侧'bwimMMhdmumw凹'y四e凹叨LFt刷刷出JMmmhs曲创1伽-mmωmmEOP时ye-Hmdd曲同-mm悦EFH!MWET-umwhad罚出江口阳时邮mMmιmEZ…阳Jmhzr巳乱Emmdm且mM1233Ebht野盹dlL刷矗川烛m站附巳Er-E-mtummm灿1TUMV肌肉dnlzut--4川中山曲mbmNgsmJJud-mLmi川中叫二则叫mmm也儿川毗M.M-M…中山的均出J叩WM刷刷此时叫ω-Mqh川曲WU·四川-m飞回mhmMJιWMm→mmmJR胆dk由-wmdF阳咱阳届J-mmmArkx-t民nMmwm时川崎盯叫叫MU巾h-hLMt盹MMι…-m帅，叫-m川N·肌」Mh图业总节咄咄LMJM川剧中J巾巾M州imWHmdMM阳-m阳叫rmw…刷lM啕N时阳t·巾，-gIbmmmmmN阳忡'啡'明伽mm∞阳hksmlmmemu川川lM阴晴mHmhmK吼叫阳岛，妇到Mmh白hbdhn川吕丁、似咄回-m←d川fdmmm创FrJ1·-fkb一，Jα臼LUMd39NEURASIANP!ATE139'E飞W.CIFIC/同ATE138'E38N，?tλ哈L~~、37一178一斗..4..H想…~田~~画画-圈垣-缘it学他2ω0.7(3)ThelateEarlyMìocenetoearlyMiddleMìocenevolcanicrαksandtheMìddleMiocenetom回国园口EEEEEEE囚回回曰凶Z凶川}。』]《【MESO-ZOIC*Notdis世ib咀.tedinthestudyareaF.g.2stra咱咐1j'8I划lidcl哑inræStU:IYarea(modifiedfromY副啤田waetal..1986)图2研究区的地层和岩性l-gra叫;2一回nd且飞dsilt;3-marinesiltand国nd;4一翩而5-sandysilt;6-muds归。ewithin四rcalationof描ndstone;7--mudstone-richalternationof回nωtone目1dmudstone;8←回nds阳时-richalt时nationofsanclstoneandmudstone;9-muds阳ne;lo-andesitic由1ddaciticVOI四nicb陀ccia;ll-and阻teanddacitelava;12-daciticp川uclasticrocks;13-一rhy.oliticla咄14-sandstoneand∞鸣lomerate;15-ar、desticpyroclasticrocksPlioceneturbiditesandstonesinthebasinformthemc以1m归口antreservoirrocksofoilandgas.ThelateEarlyMi∞enetoearlyMiddleMiocenethickvolcanicrocks,basictoacìdìcrocks，∞nstìtutethebasalpartofthebasinfills.Theyareinterpretedasproductsoftheopen­ingoftheJapanseaduringthelateEarlytoearlyMiddleMiocenetime(OtofujiandMatsu缸，1983;Tamaki,1988).ηleoverlyi吨MiddleMiocenetoQuatemarysedimentaryI'∞ksshow,asawhole,anupwardshallowingsucc臼sionattainingmo陀than5000metersinmaximumthickness,typicallybeginningwithdeep-watermudstonethroughflysch叮pealtematedsucces­sionofturbidi1esandstonesandmudstones,toshallow-marinesandymudstone,thennearshoresandstoneandfinallyQuatemarytransitional10terrestrialsediments.Anumberofvolcanicashlayersortuffsareintercalatedinthesesedimentaryrocksandmanyofth创羽町eu民dasix丑lor一179一，品‘E•.，.-且圃蜡E翻0..回回国圄-处，学雷t稼2∞0，7(3)regionalmarkersandyieldaveryimportantt∞，1bothforrecentdetailedstratigraphicworksandradìometricdating.Thefillsofthebasinhavesufferedeast-westward∞mpressionalstresssincethelatePlioceneandresultedinmanynorth-southtrendingfoldsandsomethrusts.Th臼εdeformationsplayedaveηimportantroleinmakingupthepr创entoilandgastrapsinthebasin(Suzuki,1989).1Part1:TheapplicationofheavymineralanalysistodisclosethesedimentaryprocessTokuhashi(1990,1992,1993,1996)showedatypicalcasestudythatthe归自itive∞m­binationofheavymineralanalysiswithsedimentologicalanalysisleadstoa∞mpletelydifferentideaonthesedimentaryprocess.DetailedverticalandlateralheavymineralanalysìsoftheearlyPlioceneturbiditesandstonebody,theKawaguchiFormation,locatedattheeastemmarginofthebasìn,disclosedthatheavymineral∞m怀sìtionoftheturbiditesandstonesintheeastemhalfofthe协dyare∞mpletelydìfferentfromthatìnthewestemhalfofthelx对y.Theresultsofheavymineralandsedimentologicalanalysisproposedtheideathattwokindsofturbiditesandstones,shallow-marineshelfturbidìtesandstonesintheeastemhalfanddeep-marìnesubmarine-fanturbiditesandstonesinthewestemhalf,werejuxta阳sedintheareaduringtheearlyPlioceneage.Thestudyan泪AThestudyareais1α:atedattheeastemmarginoftheNiigatabackarcsedimentarybasinandpartlyincludestheareaofMesowicbasementrocks(studyareaAinFig.l).Thegeneralstrati