貴州省盤縣地區(qū)羊圈-楚皮凹剖面中三疊統(tǒng)關(guān)嶺組上段牙形石生物地層.docx

1、北京大學(xué)學(xué)報(自然科學(xué)版)，第50卷，第2期,2014年3月ActaScientiarumNaturaliumUniversitatisPekinensis,Vol.50,No.2(Mar.2014)doi:10.13209/).0479-8023.2014.042貴州省盤縣地區(qū)羊圈-楚皮凹剖面中三疊統(tǒng)關(guān)嶺組上段牙形石生物地層孫作玉*江大勇孫元林郝維城北京大學(xué)地球科學(xué)學(xué)院.北京大學(xué)地質(zhì)博物館，北京100871;tE-mail:sunzuoyu摘要選擇貴州省盤縣地區(qū)新民鄉(xiāng)羊圈村附近羊圈-楚皮凹剖面中三登統(tǒng)關(guān)嶺組上段至楊柳井組下部地層進(jìn)行牙形石生物地層再研究，補(bǔ)充描述牙形石Neogonclolel

2、laconstrictacomma,Neogondolellaconstrictalonga,Neogondolellaconstrictabalkanica,Neogondolellaalpinaalpina,Neogondolellacf.NeogondolellaacutayParagondolellaexcelsaffParagondolellatornasis等物種.豐富了該段地層牙形石多樣性組成，并重新劃分牙形石帶，進(jìn)行區(qū)內(nèi)和區(qū)外對比。結(jié)果表明：1）羊圈-楚皮凹剖面關(guān)嶺組上段至楊柳井組下部可劃分5個牙形石帶，自下而上為Nicoraellagermanica帶（未見底界）、Nicor

3、aellakockeli帶、Neogondolellabifurcata帶、Neogondolellaconstricta帶和Neogondolellaconstrictacornuta帶（未見頂界）;2）該段地層牙形石序列區(qū)內(nèi)可與貴州省青巖剖面壟頭組上部（臺緣斜坡）、關(guān)刀（2）剖面關(guān)刀巖楔（盆地邊緣相）同名化石帶對比，區(qū)外與西特提斯生物區(qū)菊石binodosus帶trinodosus帶、reifizi帶內(nèi)的牙形石面貌組成相似；3）進(jìn)一步證明該段地層時代為中三登世安尼期Pelsonian亞期至Illyrian亞期中晚期，但未進(jìn)入拉丁期°關(guān)鍵詞牙形石；關(guān)嶺組；羊圈-楚皮凹削面；盤縣；貴州

4、省中圖分類號P52ConodontBiostratigraphyoftheUpperMemberoftheGuanlingFormationinYangjuan-ChupiwaSection,GuizhouProvince,SouthChinaSUNZuoyu+,JIANGDayong,SUNYuanlin,HAOWeichengSchoolofEarthandSpaceSciences,GeologicalMuseum,PekingUniversity,Beijing100871;tE-mail:sunzuoyuAbstractTheconodontsbiostratigraphyfromt

5、heUpperMemberoftheGuanlingFormationtothebasalYangliujingFormationinYangjuan-ChupiwaSectionwasre-analysedandtheconodontNeogondolellaconstrictacornuta,Neogondolellaconstrictalonga,Neogondolellaconstrictabalkanica,Neogondolellaalpinaalpina,Neogondolellacf.Neogondolellaacuta,Paragondolellaexcelsa、Parago

6、ndolellatornaSsisweredescribed.Basedonthestratigraphicaldistributionandmorphologicalvariationsoftheseconodonts,fiveconodontzoneswerere-establishedandtherelevantbiostratigraphiccomparisonsweremade.Theresultsrevealthat:1)FromtheUpperMemberoftheGuanlingFormationtothebasalYangliujingFormation,fiveconodo

7、ntzonescanbeinvestigated.Inascendingstratigraphicalorder,theyareNicoraellagermanicaZone(thebottomundefined),NicoraellakockeliZone,NeogondolellabifurcataZone,NeogondolellaconstrictaZone,andNeogondolellaconstrictacornutaZone(thetopundefined);2)Theseconodontzonesarecomparabletothesame-namedconodontzone

8、softheUpperLongtouFormationatQingyanSection(platform-marginslope)andoftheGuandaowedgeatGuandao(2)Section(basin-marginfacies)inGuizhouProvince,andtheseconodontsarcalsopresentintheammonoidbinodosusZone,trinodosusZone,andreitiziZoneintheWestTethys;3)Itfurtherprovesthatthestudiedstratacanbeconsideredast

9、hePelsonian-IllyriansubstagesoftheAnisianstage(MiddleTriassic),notgoingintotheLadinianoftheMiddleTriassic.Keywordsconodont;GuanlingFormation;Yangjuan-ChupiwaSection;PanxianCounty;GuizhouProvince國家自然科學(xué)基金(41372016,40920124002)和現(xiàn)代古生物學(xué)和地層學(xué)國家重點(diǎn)實驗室開放基金(123107)資助收稿日期:2013-02-05;修回日期:2013-05-27;網(wǎng)絡(luò)出版日期:2014-

10、02-13且明顯分離；齒臺略寬，邊緣傾斜，齒溝較深，齒臺前邊緣迅速收縮形成自由齒片，通常具23個細(xì)齒，臺后端通常收縮。討論本種以具有自由齒片、齒脊高且貫穿整個齒體為特征區(qū)別于中三疊世Anisian期Neogon-dolella屬內(nèi)其他牙形石種。層位貴州省盤縣新民鄉(xiāng)羊圈-楚皮凹剖面地層YC27/6.0YC27/7.6范圍內(nèi)。Neogondolellacf.Neogondolellaacuta(KozurinKozur,1972)(圖3(q)1972GondolellaacutaKozurandMock,taf.2,fig.121975Gondolellaacuta,Trammer,pl.24,f

11、igs451980Gondolellaacuta,Kozur,taf.3,fig.3;taf.4,fig.41999Neogondolellaacuta,Narkiewicz,pl.1,figs.12描述個體較小，齒脊較低，細(xì)齒均勻且融合，僅最頂端分離，無自由齒片；齒臺具略傾斜的臺緣，齒溝明顯，齒臺邊緣迅速向前、向后收縮，使齒體中間寬，兩端尖削。討論僅一枚標(biāo)本，形態(tài)與Kozur等)描述命名的Gondolellaacuta吻合，但由于標(biāo)本較少，故暫鑒定為Neogondolellacf.Neogondolellaacutao層位貴州省盤縣新民鄉(xiāng)羊圈-楚皮凹剖面YC24/1.7采樣點(diǎn)處。參考文獻(xiàn)1

12、WangLiting,LiJinling,WangXinjin,etal.BiostratigraphyofTriassicmarinereptilesinSouthwestGuizhouanditsadjacentarea.ActaGeologicaSinica(EnglishEdition),2001,75:349-353LiChun.FirstrecordofprotorosauridReptile(Order:Protorosauria)fromtheMiddleTriassicofChina.ActaGeologicalSinica,2003,77(4):419-4232 LiChu

13、n,RieppelO,LaBarberaMC.ATriassicaquaticprotorosaurwithanextremelylongneck.Science,2004,305(24)：1931LiChun,WuXiaochun,ChengYennien,etal.AnunusualarchosaurianfromthemarineTriassicofChina.Naturwissenschaften,2006,93:200-2063 JiangDayong,SchmitzL,HaoWeicheng,etal.AnewmixosauridichthyosaurfromtheMiddleTr

14、iassicofChina.JVertebrPaleontol,2006,26(1):60-69JiangDayong,MaischMW,SunZuoyu,etal.AnewspeciesofLariosaurus(Reptilia,Sauropterygia)fromtheMiddleAnisian(MiddleTriassic)ofsouthwesternChina.NJbGeolPalSontAbh,2006,242(1):19-424 JiangDayong,MaischMW,HaoWeicheng,etal.Nothosaurusyangjuanensisn.sp.(Reptilia

15、,Sauropterygia,Nothosauridae)fromtheMiddleAnisian(MiddleTriassic)ofGuizhou,SouthwesternChina.NJbGeolPalSontM,2006,5:257-276JiangDayong,SchmitzL,MotaniR,etal.MixosauridichthyosaurPhalarodoncfPhalarodonfraasifromtheMiddleTriassicofGuizhouProvince,China.JPaleontol,2007,81(3):602-6055 JiangDayong,Rieppe

16、lO,MotaniR,etal.AnewMiddleTriassiceosauropterygian(Reptilia,Sauropterygia)fromSouthwesternChina.JVertebrPaleontol,2008,28(4):1055-1062JiangDayong,MotaniR,HaoWeicheng,etal.Firstrecordofplacodontoidea(Reptilia,Sauropterygia,placodontia)fromtheeasternTethys.JVertebrPaleontol,2008,28(3):904-9086 JiangDa

17、yong,MotaniR,HaoWeicheng,etal.Newprimitiveichthyosaurian(Reptilia,Diapsida)fromtheMiddleTriassicofPanxian(Guizhou,southwesternChina)anditspositionintheTriassicBioticRecovery.ProgNatSci,2008,18(10):1315-1319陳孝紅，程龍.貴州普安中三疊統(tǒng)混魚龍(魚龍類:爬行動物)一新種.古生物學(xué)報，2010,49(2):251-2607 童金南，殷鴻福.早三度世生物與環(huán)境研究進(jìn)展.古生物學(xué)報，2009,48(

18、3):497-508JiangDayong,MotaniR,HaoWeicheng,etal.BiodiversityandsequenceoftheMiddleTriassicPanxianMarineReptileFauna,GuizhouProvince,China.ActaGeologicaSinica(EnglishEdition),2009,83(3):451-459)5郝維城，孫元林，江大勇，等.盤縣動物群研究進(jìn)展.北京大學(xué)學(xué)報：自然科學(xué)版，2006,42(6):217-223SunZuoyu,SunYuanlin,HaoWeichcng,etal.ConodontsEviden

19、cefortheAgeofthePanxianFauna,Guizhou,China.ActaGeologicaSinica,2006,80(5):621-60316 陳立德，王成源.貴州西南部三疊系楊柳井組的時代.地層學(xué)雜志,2009,33(1):98-103MotaniR,JiangDayong,TintoriA,etal.FaunalassemblagesofAnisian(MiddleTriassic)marinereptilesfromPanxian,Guizhou,China.JVertebrPaleontol,2008,28(3):900-903SunZuoyu,HaoWeich

20、eng,SunYuanlin,etal.SilicifiedAnisianspirifcrinidsfromGuizhou,southernChina.ActaPalaeontPol,2009,54(1):61-68SunZuoyu,HaoWeicheng,SunYuanlin,etal.TheconodontgenusNicoraellaandanewspeciesfromtheAnisianofGuizhou,SouthChina.NJbGeolPalaeontAbh,2009,252(2):227-235BudurovK,StefanovS.Platform-Condontenundih

21、reZoneninderMittlerenTriasBulgariens.MittGesGeolBergbaustud,1972,21:829-86317 KozurH.RevisionderconodontenzonierungderMittel-undObertriasdestethyalcnFauncnreichs.GeolPalflontMittInnsbruck,1980,10:79-172PisaG,PerriC,VeneriP.UpperAnisianconodontsfromDontandM.BiveraFormations,southernAlps(Italy).RivIta

22、iPaleontStrat,1980,85:807-82818 Marquez-AliagaA,Valenzuela-riosJI,CalvetF,clal.MiddleTriassicconodontsfromnortheasternSpain:biostratigraphicimplications.TerraNova,2000,12(2):77-83TrammerJ.StratigraphyandfaciesdevelopmentoftheMuschelkalkinthesouth-westernHolyCrossMts.ActaGeolPol,1975,25(2):179-21619

23、KozurH.Integratedammonoid,conodontandradiolarianzonationoftheTriassicandsomeremarkstostage/substagesubdivisionandthenumericageoftheTriassicstages.Albertiana,2003,28:57-74NicoraA.Conodont-fauna,stratigraphicpositionandrelationstotheTethyansuccessionsoftheShoshonensisZone(Pelsonian)ofNevada.RivistaIta

24、lianadiPalcontologiaeStratigrafla,1976,82(4):627-64820 王志浩，鐘端.滇東、黔西和桂北不同相區(qū)的三會紀(jì)牙形剌.微體古生物學(xué)報，1994,11(4):379-412武桂春，姚建新，紀(jì)占勝，等.貴州青巖剖面青巖階上部牙形石的發(fā)現(xiàn)及其意義.地質(zhì)學(xué)報，2008,82(2):145-15621 王紅梅，王興理，李榮西，等.貴州羅甸邊陽鎮(zhèn)關(guān)刀削面三整紀(jì)牙形石序列及階的劃分.古生物學(xué)報,2005,44(4):611-626KozurH.DieConodontengattungMetapolygnathusHayashi,1968undihrstratig

25、raphischerWert.GeolPalSontMittInnsbruck,1972,2(11):1-3722 NarkiewiczK.ConodontbiostratigraphyoftheMuschelkalk(MiddleTriassic)inthecentralpartofthePolishLowlands.GeolQ,1999,43(3):313-325楊守仁，王新平，郝維城.廣西西部早、中三疊世牙形石序列.北京大學(xué)學(xué)報：自然科學(xué)版，1986(4):90-106黃金元，張克信，張啟躍，等.云南羅平中三疊世大凹子剖面牙形石生物地層及其沉積環(huán)境研究.微體古生物學(xué)報，2009,26(3

26、):211-22423 張啟躍，周長勇，呂濤，等.云南中三登憂羅平生物群地層時代的厘定：來自牙形石的證據(jù).中國科學(xué):D根，2009,39(3):300-305BudurovK,GanevM,StefanovS.Conodontenstr-atigraphiederAnis-Ladin-GrenzschichteninderTriasdesElcna-Tvardica-Passes(Zentralbalkan).GeolBale,1979,9(2):105-11024 ZawidzkaK.ConodontstratigraphyandsedimentaryenvironmentoftheMusc

27、helkalkinUpperSilesia.ActaGeolPol,1975,25(2):217-257KovacsS.Ontheevolutionofexcelsa-sXocY.intheUpperLadinian-Carnian(conodonta,genusGondolella,Triassic).SchriftenreihcderErdwiss-enschaftlichenKommissionen,1983,5:107-12025 BudurovK,StefanovS.NeueDatenUberdieConodontenchronologiederBalkanidcnmittleren

28、Trias.CrAcadBulgSci,1975,28(6):791-794BudurovK,TrifonovaE.ConodontandfbraminiferaisuccessionsfromtheTriassicofBulgaria.GeologicaBalcanica,1995,25:13-1926 KozurH,MockR.NcueConodontcnausderTriasderSlowackclundihrestratigraphischcBedeutung.GeolPalMontMiffInnsbruck,1972,2(4):1-20KovacsS,KozurH.Stratigra

29、phischeReichweilederwichtigstenConodonten(ohneZahnreihen-Conodonten)derMittel-undObertrias.GeolPaleontolMittInnsbruck,1980,10(2):42-78NarkiewiczK,SzulcJ.Controlsonmigrationofconodontfaunainperipheraloceanicareas.AnexamplefromtheMiddleTriassicoftheNorthernPeri-TethysGeobios,2004,37:425-43627 MosherLC

30、,ClarkDL.MiddleTriassicconodontsfromthePridaFormationofthenorthwesternNevada.JournalofPaleontology,1965,39(4):551-565KozurH,KrainerK,LutzD.MiddleTriassicconodontsfromtheGartnerkofcl-ZielkofelArea(CamicAlps,Carinthia,Austria).JbGeolB-A,1994,137(2):275-28728 NicoraA,KovdcsS.ConodontfaunafromtheRotelli

31、forme,McekiandOccidentaliszones(MiddleTriassic)ofHumboldtrange,Nevada,westem-NorthAmerica.RivistaItalianadiPaleontologiaeStrati-grafia,1984,90(2):135-164ChhabraNL,KumarS.LateScythianthroughEarlyCarnianconodontassemblagesandtheirbiostratigra-phicsignificancefromoffshorecarbonatesofnorthernKumaun.Teth

32、ysHimalaya,India.RevuedeMicropaleontologie,1992,35(1):3-2129 SweetWC,MosherLC,ClarkR,etal.ConodontbiostratigraphyoftheTriassic/SweetWC,BergstromSM.Symposiumonconodontbiostratigraphy.GeolSocAmerMem,1971,127:441-465丁梅華，黃清華.貴州紫云石頭寨晚二疊世-中三疊世牙形石動物群及其生態(tài)意義.地球科學(xué)：中國地質(zhì)大學(xué)學(xué)報，1990,15(3):291-29830 王成源，王志浩.珠穆朗瑪峰地區(qū)

33、三迭紀(jì)牙形刺.珠穆朗瑪峰地區(qū)科學(xué)考察報告，19661968,古生物，第二分冊.北京：科學(xué)出版社,1976:387-416KovdcsS,NicoraA,Szab6I,etal.ConodontbiostratigraphyofAnisian/LadinianboundarysectionsintheBalatonUpland(Hungary)andintheSouthernAlps(Italy).CourierForschInstSenckenberg,1990,118:171-21931 KovdcsS.ConodontsofstratigraphicalimportancefromtheA

34、nisian/LadinianboundaryintervaloftheBalatonHighland,Hungary.RivItPalcontStrat,1994,99(4):473-514MosherLC.TriassicconodontsfromwesternNorthAmericaandEuropeandtheircorrelation.JPaleontol,1968,42(4):89594632 MosherLC.TriassicconodontsfromBritishColumbiaandthenorthernArcticIslands.GeolSurvCanadaBull,197

35、3,222:141-193KozurH,MostlerH.ProblemederConodontcn-forschunginderTrias.GeolPSlaontMittInnsbruck,1971,1(4):1-1933 KozurH,MostlerH.DieConodontenderTriasundihrstratigraphischerWert.AbhandlungenderGeolo-gischenBundesanstalt,1972,28(1):J-53BudurovK.Structures,evolutionandtaxonomyoftheTriassicplatformcono

36、donts.GeologicaBalcanica,1976,6(1):13-2034 Kov4csS,LessGY,PirosO,etal.TriassicformationsoftheAggtelek-RudabanyaMountains(NortheasternHungary).ActaGeologicaHungarica,1989,32:31-63KovicsS,PapSovdJ,PerriMC.NewMiddleTriassicconodontsoftheGondolellaszabdi-G.trammerilineagefromtheWestCarpathianMtsandfromt

37、heSouthernAlps.ActaGeologicaHungarica,1996,39:103-12835 MecoS.ConodontbiostratigraphyofTriassicpelagicstrata,Albania.RivistaItalianadiPaleontologiacStratigrafia,1999,105(2):251-266KrystynL.DasEpidaurus-Profil(Griechenland)-einBeitragzurConodonten-StandardzonierungdestethyalcnLadinundUntcrkam.OsterrA

38、kadWiss,ScbriftenrErdwissKomm,1983,5:231-25836 YangShouren.Ladinian-CarnianconodontsandtheirbiostratigraphyinAsia/ProceedingoftheIGCPSymposiumonGeologyofSEAsiaandAdjaccnAreas.JournalofGeology,SeriesB,1995(5/6):127-138夏風(fēng)生，張放.聶拉木中三登統(tǒng)上下界線附近的牙形類沙金庚，王啟飛，盧輝楠.羌塘盆地微體古生物.北京：科學(xué)出版社,2005:198-2091999年，在貴州省西南部盤縣新

39、民鄉(xiāng)羊圈村及鄰區(qū)普安縣青山鄉(xiāng)附近（圖1）中三疊統(tǒng)美嶺組上段地層中發(fā)現(xiàn)富集成層的海生爬行動物、魚類及多門類無脊椎動物化石，稱為盤縣動物群。動物群中數(shù)量豐富、骨骼連接完整的爬行動物化石受到國內(nèi)外學(xué)術(shù)界的廣泛關(guān)注，已描述命名10屬10種，包括魚龍類、鰭龍類（幻龍、鷗龍、楣齒龍、原始鰭龍等）、原龍類、初龍類、龍龜類Q-，另外仍有一些新物種、新類群沒有研究。這些數(shù)量:豐富、高分異度、位于食物鏈高端的大型食肉類脊椎動物的出現(xiàn)，表明盤縣動物群已具有典型的中-新生代型生物和生態(tài)系統(tǒng)結(jié)構(gòu)特征，是二疊紀(jì)生物大滅絕后，三疊紀(jì)生物復(fù)蘇并輻射的標(biāo)志性生物群之一盤縣動物群保存于關(guān)嶺組上段距上覆地層楊柳井組底界約50m的一

40、套含45層凝灰?guī)r的由泥質(zhì)灰?guī)r、白云質(zhì)灰?guī)r、泥質(zhì)白云巖和瘤狀灰?guī)r組成的厚約3m的巖層中（成。為確定盤縣動物群的地層序列和地質(zhì)時代，孫元林等20012003年在盤縣新民鄉(xiāng)羊圈村附近對羊圈-楚皮凹剖面（起點(diǎn)：25。3,48”村,104°53'51"E;終點(diǎn):25。31'44個，104。53'46%,見圖1）進(jìn)行了實測，在關(guān)嶺組上段至楊柳井組F部系統(tǒng)采集了牙形石樣品。后經(jīng)研究，依據(jù)牙形石化石的地層分布和形態(tài)譜系演化關(guān)系特征，劃分出4個牙形石帶，確定盤縣動物群位于牙形石Nicoraellakockeli帶，時代為中三疊世安尼期的Pclsonian亞期另外，還發(fā)

41、現(xiàn)該剖面關(guān)嶺組上段下部以Nicoraella屬齒片形分子富集為特征，而上部則以Neogondolella和Paragondolella屬齒臺形分子富集為特征，并旦在上覆地層楊柳井組下部發(fā)現(xiàn)牙形石圖1盤縣動物群和研究剖面羊圈-楚皮凹剖面地理位置Fig.1GeographicallocationofthePanxianFaunaandtheYangjuan-ChupiwaSectionNeogondolellaconstricta,表明安尼階/拉丁階界線進(jìn)入楊柳井組3】。這一認(rèn)識得到陳立德等證實。北京大學(xué)江大勇教授組織國際合作團(tuán)隊對盤縣動物群化石層高精度地層序列、生物組合特征、古環(huán)境演變等進(jìn)行了系

42、統(tǒng)研究l，4J81oSun等"】對羊圈一楚皮凹剖面關(guān)嶺組上段下部Nicoraella屬多分子組成特征做了分析，描述命名一牙形石物種；在其上部牙形石Neogondolellabifurcata帶至Neogondolellaconstricta帶內(nèi)，利用酸處理獲得保存完好的腕足類殼體20】，并系統(tǒng)補(bǔ)充采集牙形石樣品。本文以這些牙形石樣品為研究對象，并結(jié)合對已報道化石的再研究，進(jìn)一步分析關(guān)嶺組上段牙形石組成特征、譜系演化關(guān)系及其在區(qū)內(nèi)、區(qū)外地層劃分對比方面的意義，以提高該層段劃分對比的精度。1牙形石生物地層描述貴州省盤縣羊圈-楚皮凹剖面簡稱YC,位于貴州省盤縣新民鄉(xiāng)羊圈村。剖面起點(diǎn)地理坐標(biāo)

43、:25°3T48”N,104°53'51”E;剖面終點(diǎn)地理坐標(biāo)：25°31'44"N,104°53,46"Eo上覆地層：楊柳井組（Ty）YC29（厚30.0m,未見項），中-厚層塊狀白云巖，含軟骨魚魚牙，牙形石分布如下YC29/3.0Neogondolellaconstrictacornuta（YC29為層號，3.0為本采樣點(diǎn)距此層層底的地層真厚度，下同）整合關(guān)嶺組上段（T2g3）YC28（厚2.0m）,黑灰色團(tuán)塊狀灰?guī)r，牙形石分布如下YC28/2.0首次出現(xiàn)牙形石Neogondolellaconstrictacorn

44、uta帶帶分子YC28/1.5ParagondolellaexcelsaYC28/0.8ParagondolellaexcelsaYC27（厚8.4m）,泥質(zhì)條帶灰?guī)r，牙形石分布如下YC27/7.6Paragondolellaexcelsa,Neogondolellaal-pinaalpina,NicoraellaparabudaensisYC27/7.0NeogondolellaconstrictaYC27/6.0Paragondolellaexcelsa,Neogondolellaal-pinaalpinaYC27/4.0Neogondolellabifiircata,Neogondole

45、llaconstrictaYC27/2.4Neogondolellabijurcata,Neogondolellacon-stricta,NicoraellaparabudaensisYC27/0.8NeogondolellabifiircataNeogondolellaconstricta,Neogondolellaconstrictalonga,Neogondolellaconstrictabalkanica,NeogondolellaexcentricaYC26（厚3.2m）,灰色中層含海百合莖灰?guī)r，底部為0.5m厚的蠕蟲狀白云質(zhì)灰?guī)r，含腹足類化石：Promatildasp.;腕足類化石

46、：Tulungospiriferstracheyi,PunctospirellafragiliSyPseudospiriferinapinguis,Pseudospiriferinamulti-costata,Neoretziasp.;牙形石分布如下YC26/2.7Neogondolellaconstricta,Neogondolellaconstrictabalkanica,Neogondolellaexcentrica,Paragon-dolellanaviculaYC26/2.6Neogondolellabifurcata,Neogondolellaconstricta,Nicorael

47、laparabudaensisYC26/2.0Neogondolellabulgarica,Neogondolellabifurcata,NeogondolellaconstrictaYC26/1.4Neogondolellabifurcata,NeogondolellabulgaricaYC25（厚4.5m）,灰色中層含泥質(zhì)條帶和燧石結(jié)核灰?guī)r,頂部0.6m為白云質(zhì)灰?guī)r，牙形石分布如下YC25/3.6Paragondolellatornaesis,Neogondolellaconstricta,NicoraellakockeliYC25/2.0NicoraellaparabudaensisYC

48、25/1.5NeogondolellabifurcataYC25/0.0首次出現(xiàn)牙形石Neogondolellaconstricta帶的帶分子Neogondolellaconstricta,另有Neogondolellabulgarica,NicoraellakockeliYC24（厚2.9m）,塊狀泥質(zhì)條帶灰?guī)r，牙形石分布如下YC24/2.5Neogondolellabifurcata,Neogondolellabulgarica,NicoraellakockeliYC24/1.7Neogondolellabifurcata,Neogondolellabulgarica,Neogondole

49、llacf.Neogondolellaacuta,Neogondolellaexcentrica,Paragondolellatornaesis,NicoraellakockeliYC23（厚22.0m）,塊狀泥質(zhì)條帶灰?guī)r，牙形石分布如下YC23/20.8首次出現(xiàn)牙形石Neogondolellabifurcata帶的帶分子Neogondolellabifurcata,另有Neogondolellabulgarica,NeogondolellaexcentrictaYC23/19.5Neogondolellasp.indet.,NicoraellakockeliYC23/18.5Neogondo

50、lellabulgarica,NicoraellakockeliYC23/16.0Nicoraellakockeli,NicoraellaparabudaensisYC23/14.0ParagondolellatornaesisyNeogondolellabulgarica,NicoraellakockeliYC23/8.0Nicoraellakockeli,NicoraellagermanicaYC23/7.ONicoraellakockeliYC23/5.0Paragondolellatomaesis,NicoraellakockeliYC23/3.0Nicoraellakockeli,N

51、icoraellagermanica,NicoraellaparabudaensisYC23/2.0Nicoraellakockeli,NicoraellagermanicaYC22（厚1.2m）,灰色薄層灰?guī)r，單層厚度210cm,牙形石分布如下YC22/0.2NicoraellakockeliYC21（厚2.0m）,灰黑色塊狀灰?guī)r，牙形石分布如下YC21/1.9Nicoraellakockeli,NicoraellaparabudaensisYC20（厚0.6-1m）,巖溶白云巖，底部含-層凝灰?guī)r，厚約2cmYC19（厚1.2m）,黑灰色薄層泥質(zhì)、白云質(zhì)灰?guī)r，單層厚度0.52cmYC18（厚

52、0.057.2m）,黃至白色凝灰?guī)rYC17（厚1.8m）,黑至黑灰色泥質(zhì)、白云質(zhì)灰?guī)r，夾3層約1cm厚的凝灰?guī)r，含魚和海生爬行類化石，牙形石分布如下YC17/1.1NicoraellakockeliYC16（厚2.0m）,黑灰色泥質(zhì)灰?guī)r，含海生爬行類和雙殼類化石YC15（厚4.0m）,灰色孺狀泥質(zhì)灰?guī)r，含雙殼類和腕足類化石：Mentzeliamentzeli,Mentzeliamulticastata,Mentzeliacf.Mentzeliabalatonica,Adygeilaelongata;牙形石分布如下YC15/3.0Nicoraellakockeli,Nicoraellagerma

53、nica,NicoraellaparakockeliYC15/2.5NicoraellaparabudaensisYC15/2.0Nicoraellakockeli,NicoraellagermanicaYC14（厚0.5m）,灰色端蟲狀灰?guī)rYC13（厚2.5m）,紋層狀泥質(zhì)灰?guī)r、白云質(zhì)灰?guī)r，牙形石分布如下YC13/1.5NicoraellagermanicaYC12（厚2.5m）,泥質(zhì)條帶灰?guī)r，牙形石分布如下YC12/2.0NicoraellagermanicaYC12/0.5NicoraellakockeliYC11（厚2.0m）,紋層狀泥質(zhì)灰?guī)r、白云質(zhì)灰?guī)rYC11/2.0,YC11/1.

54、0未發(fā)現(xiàn)牙形石YC10（厚1.5m）,淺灰色白云巖YC9（厚2.0m）,紋層狀泥質(zhì)灰?guī)r、白云質(zhì)灰?guī)rYC8（厚1.5m）,灰色泥質(zhì)條帶灰?guī)r，牙形石分布如下YC8/1.2Nicoraellakockeli,Nicoraellagermanica,YC8/0.8首次出現(xiàn)Nicoraellakockeli帶的帶分子Nicoraellakockeli、另有Nicoraellagermanica,NicoraellagermanicaNicoraellakockeli過渡類型YC8/0.6Nicoraellagermanica,NicoraellagermanicaNicoraellakockeli過渡類

55、型YC7（厚0.5m）,灰色蠕蟲狀灰?guī)rYC6（厚1.2m）,灰色厚層灰?guī)r，牙形石分布如下YC6/1.0NicoraellagermanicaYC5（厚2.5m）,灰色泥質(zhì)條帶狀灰?guī)r，含海白合莖，腕足類化石：Coenothyrissp.,Coenothyrisvulgaris,AdygeilaelongataYC4（厚4.5m）,灰色中層灰?guī)r，牙形石分布如下YC4/0.5NicoraellagermanicaYC3（厚2.0m）,薄-中層灰?guī)r，表面有溶蝕現(xiàn)象，含弓蛟軼類牙齒，牙形石分布如下YC3/0.0Nicoraellagermanica,Nicoraellagermanica一Nicorae

56、llakockeli過渡類型YC2（厚3.0m）,紋層狀泥質(zhì)條帶灰?guī)rYC1（厚1.5m）,灰色中層灰?guī)r，底部含燧石結(jié)核2牙形石生物地層劃分及對比羊圈-楚皮凹剖面關(guān)嶺組上段至楊柳井組下部地層中采集的牙形石樣品鑒定出牙形石3屬14種,屬種地層分布特征見圖2。依據(jù)牙形石屬種地層分布情況和屬種演化關(guān)系分析,Sun等淄建立了4個牙形石帶：Nicoraellagermanica帶、Nicoraellakockeli帶、Neogondolellahifurcata帶和Neogondolellaconstricta帶，地質(zhì)時代延限大致對應(yīng)中三疊世安尼期Peisonian-Hlyrian亞期中晚期，其中Nico

57、raellagermanica帶和Nicoraellakockeli帶的定義、化石組合特征、區(qū)內(nèi)及區(qū)外對比已在文獻(xiàn)16,19中詳細(xì)闡述，不再贅述。本文對羊圈-楚皮凹剖面原Neogondolellabifurcata帶和Neogondolellaconstricta帶地層段進(jìn)行再研究，依據(jù)牙形石NeogondolellabifurcataNeogondolellaconstricta和Neogondolellaconstrictacornuta地層分布情況，厘定原化石帶建帶定義，情況如下。Neogondolellabifurcata帶底界以帶分子首次出現(xiàn)為標(biāo)志，地層延續(xù)為距羊圈-楚皮凹剖面底界6

58、5.971.0m。除帶分子外，還含有Nicoraellakockeli,Nicoraellaparabudaensis,Neogondolellabulgarica,Neogondolellaexcentrica,Neogondolellacf.Neogondolellaacuta,Paragondolellatornaesis以及豐富的枝形分子。Neogondolellabifurcata最早發(fā)現(xiàn)于保加利亞的GoloBardoMountain地區(qū)，以其為帶分子建立的化石帶被認(rèn)為是中三疊統(tǒng)安尼階Illyrian亞階最下部的一個牙形石帶*。在西特提斯生物區(qū)，Neogondolellabifurc

59、ata常見于保加利亞、斯洛文尼亞、西班牙、意大利等地Illyrian亞階下部，與菊石trinodosus帶大致對應(yīng)小，以及波蘭HolyCrossMountains和匈牙利BalatonHighland地區(qū)的Pelsonian亞階上部（22,25OKozur26認(rèn)為Neogondolellabifurcata帶下限口丁延伸至Pelsonian亞階上部，與菊石binodosus帶底界大致對應(yīng)。在北美（太平洋生物區(qū)），Neogondolellabifurcata見于菊石shoshonensis帶至occidentalis帶'"J。在國內(nèi)，Neogondolellabifurcata見于貴州平壩孔隴場-魚隴的板納組泥晶灰?guī)r段（即第二段）08】、貴州青巖剖面壟頭組下部29】和貴州關(guān)刀剖面