GEOLOGICA BALCANICA, 25. 3-4, Sofia, August. 1995, p. 97-109
Lower Triassic conodont stratigraphy
1 Kiril Budurov , Milan Suda,-2
'Geologica/Institute, Bulgarian Academy of Sciences, 1113 Sofia 1Faculty of Mining and Geology. University of Belgrade, 11 000 Belgrade
(submitted 19. 01. 1995; accepted for publication 24. OJ. 1995)
K. liyoypoe, II. Cy0a6. Hu:NCHempuac06aJI KOHOOOHmHaJI cmpamui!pa(/jUJI. npoBe,D;eHO KOHO.D;OHTHoe CTpaTHrpacj>H'Iecxoe pac'fJieHeHHe HHliCHero TpHaca c o6cYJK.ll.eHHeM Bonpoca o rpaHHLte nepMb-TpHac. C.D;eJiaHo o6o6w.eHHe H aKTyaJIHJaLtHJI noJI}"feHHbiX .D;aHHbiX Ja nocne.D;HHe ro.n;bl, HO aKLteHT nocTaBJieH Ha pe3yJibTaTbl HCCJie.D;OBaHHJI co6palfHbiX aBTopaMH KOHO.D;OHT H3 fHMaJiaeB H H3 pa3HbiX 'taCTeH EBponbl. KoHBeHLtHOHaJibHall rpaHHI.(a nepMb-TpHac nona.n;aeT B CTpaTHrpacj>H'feCKHH oXBaT Clarkina subcarinata-Anchignathodus typicalis C.-R.-Z., HO xaK aJibHepHaTHBHaJI B03MOlKHOCTb no KOHO.D;OHTaM, aMMOHHTaM H .n;pyrOH cj>ayHe YJCa3aHbl HH3bl Kashmirel/a kumme/i R.-Z. noJIHOe KOHO.D;OH THOe pac'fJieHeHHe HHlKHero TpHaca 060CHOBaHO Ha 14 KOHO.D;OHTHbiX 30Hax, a HMeHHO: .n;JIJI rpHHC6axa (HHlKHHH HHACKHH 11pyc) - C/arkina subcarinata-Anchignathodus typica/is C.-R.-Z., Anchignathodus parvus l.-Z., lsarcicel/a isarcica R.-Z., C/arkina carinata A.-Z.; .n;JIJI .D;HHepcxoro (BepXHHH HHACKHH 11pyc)- Kashmirel/a kummeli R.-Z., N eospathodus dieneri-Neospathodus cristagalli C.-R.-Z. H 'laCTb Kashmirel/a nepalensis R.-Z.; .n;JIJI CMHTCKOfO (HHlKHHH OJieHeKCKHH llpyc) cpe.n;HHe H BepXHHe 'laCTH Kashmirel/a nepa/ensis R.-Z., Neospathodus waageni A.-Z., Scythogondolel/a milleri R.-Z. H Parachirognathus-Furnishius Beds; .D,JIJI cnaTcKoro (BepxHHH oneHeKCKHH .Rpyc) - Neospathodus triangularis-Neospathodus hommeri A.-Z., Platyvil/osus-Foliel/a Beds H Kashmirel/a timorensis R. -Z. YcTaHoBJieHHeM Kashmirel/a gondolelloides R.-Z. npoBe.n;eHa rpaHHLta MelKD.y HHJKHHM H cpe.aHHM TpHaCOM. Abstract. A conodont stratigraphic subdivision of the Lower Triassic is made, and considerations about the Permian{friassic boundary are developed. Data received during the last few years are gener alized with emphasis laid on results obtained on conodonts found by the authors in their samples from the Himalayas and different parts of Europe. The conventional Permian{friassic boundary is situated in the stratigraphic range of Clark ina subcarinata-Anchignathodus typicalis C.-R.-Z. although as an alter native possibility (based on conodont, ammonite and other faunas) the base of Kashmirella kummeli R. Z. is indicated. The conodont subdivision of the Lower Triassic is based upon 14 conodont zones as follows: Clark ina subcarinata-Anchignathodus typica/isC.-R .-Z .,Anchignathodus parvus l.-Z., lsarcicella isarcica R.-Z., Clarkina carinata A.-z. - for the Griesbachian (Lower Induan); Kashmirella kummeli R.-z., Neospathodus dieneri - Neospathodus cristagal/i C.-R.-Z., and parts of Kashmirel/a nepalensis R.-z. - for the Dienerian (Upper lnduan); middle and upper parts of Kashmirel/a nepa/ensis R. -Z., Neospathodus waageni A.-Z., Scythogondolella milleri R.-z. and Parachirognathus - Furnischius Beds -for the Smlthian (Lower Olenekian), and Neospathodus triangularis - Neospathodus hommeri A. -Z., Platyvil/osus- Foliella Beds and Kashmire/la timorensis R.-Z., - for the Spathian (Upper Olenekian). The boundary between the Lower and Upper Triassic is set with proving of theKasmire/la gondolelloides R.-z.
Introduction Detailed investigation on Early Triassic conodont fauna provided for this presenta tion of our understanding of conodont stratigraphy of the lowermost Triassic. The studies were primarily based on rich collections from various localities (Guryul Ra- 7 Geologica Balcanica, 25, 3-4 97 vine, Mandakpal and Khrew around Srinagar- Jammu and Kashmir State India, collected personally by K. J. Budurov during 1980) of Kashmir Himalayas, and from Bulgaria, Yugoslavia, etc. Moreover, all published data on Early Triassic conodonts have been considered. The so compiled Early Triassic conodont stratigraphy of the Tethyan-Pacific conodont area is a part of the our earlier proposed Triassic con odont zonal standard (B u d u r o v et a!., 1983, 1985) and has been partly published several times (B u d u r o v et a!., 1986, 1987, 1988) but never as complete as now. Early Triassic conodont faunas contain the stratigraphically important sepa rate-element conodont genera: Anchignathodus, Isarcicella, Neospathodus, Spathoicriodus, Kashmirella, Clarkina and Borinella. With their specific blade and cavitus, representatives ofAnchignathodus possess the aspect of Paleozoic conodonts. Recently, they have been more often considered as components of the multielement genus Hindeodus. The rapid development and the subsequent flourishment of the probably monoelement genera Neospathodus and Kashmirella control the stratigra phy within the time span Dienerian Stage -Spathian Stage. These conodonts differ morphologically in a drastic manner from the Griesbachian Anchignathodus and Isarcicella. Representatives of Neospathodus are simply organized, and consist of a thin blade with considerable welded denticles, and a narrow basis which broadens only around the small cavitus. Quite different from them, the species of Kashmirella (with type species Kashmirel/a albertii Budurov, Sudar & Gupta) possess a more massive blade with considerably free denticles and a lateral thickenning near the basis; the basis is broader, often with rectangular outline from the bifurcating loop; thus they are even similar to some Late Triassic platform conodonts. Species ofClarkina penetrate in the Early Triassic, and especially when favoured by the facies control they show a good development; a rapid development during the Smithian and Spathian age show the representatives of Borinella (with type species Neogondolella buurensis Dagis). The proposed (B u d u r o v et a!. 1986, 1987, 1988) Early Triassic conodont zonal standard is based upon the combination of the ranges of taxa of the Early Triassic conodont genera. Conodont successions of the Griesbachian and the Permian-Triassic boundary The boundary beds of the Lower Griesbachian (Otoceras woodwardi Zone) are penetrated by Upper Dorashamian conodonts Clarkina subcarinata (Sweet) and single Clarkina orienta/is (Barsakov & Korovela). The principal conodont is Anchignathodus typicalis Sweet. In fact, almost the whole range of the Griesbachian (without Proptychites strigatus Zone) is characterized by representatives of the Pa leozoic genus Anchignathodus. The lower part of the Lower Griesbachian (the lower part ofOtoceras woodwardi Zone) is relatively poor in conodont fauna. The characteristics of the first conodont zone is given by Anchignathodus typicalis Sweet. Clarkina subcarinata (Sweet) and Clarkina carina/a (Sweet) are also found. According to Sweet et. a!. (1971), this interval equals Otoceras concavum Zone (the lower part of the Lower Griesbachian). We found these conodont species in Guryul Ravine, in the lower parts of the Dorashamian (Changxingian) equivalent to unit D of Zewan Formation, and in the lower parts of the Lower Griesbachian, equivalent to parts of Otoceras woodwardi
Zone or to units E1 and E2 (part) of Zewan Formation. This indicates that the use of Anchignathodus typicalis conodont Zone (with a very wide stratigraphic range) is not very correct and leads to incorrect stratigraphic characteristics. Instead of this Zone we suggest the Clarkina subcarinata-Anchignathodus typicalis C.-R.-Z. with a range that, though narrower, defines the upper parts of the Dorashamian- the lower parts of the Lower Griesbachian. In all cases the assumed Permian-Triassic boundary falls
98 CONODONT ZONAL >- AMMONOID ZONES (I') a:: LLJ ...: AGE STANDARD c::l CANADA TETHYS -a:: z: LLJ ::::> (Tozer,l967,em. (Budurov emend.) (I') 0 (Dagis, et al., 1987, Q:l by Da g is , l985) 198 5) LOWER ANISIAN (part) Kashmirella gondolel/aides R.-z.
Keyserlingites Tazeriteras Kashmirel/a timorensis R.- Z. subrobustus pakistanum z < ( Prohungarites} Neospathodus triangularis - H "Keyserlingites" :I: E- pilaticus Neospathodus hommeri A. -z. c..< Vl Spi. collin- soni A. - z. z Tirolites - I < Platyvillosus - H Columbites ~ ? Folie /Ia Beds "'z Wasatchites A. pluriformis Scy. mil/eri ...:I R. -z. "'0 tardus Meekaceras < > z gracilitatis Neospathodus < Parachirognathus - H waageni :I: Furnischius E- H A. -z. Beds ~ ;I! u Vl "' H Euflemingites Flemingites )-ocr> Vl c.:.-."" Vl romunderi flemingianus < . < Ksh . nepa/ensis ~ H R. ~ -:z,... >- a: - -- ::>OS ... E- Vavilovites Rotundatus - 0 ...... svedrupi Vo/utus =..... "' E- .c "';.: z > ..... 0 < Neospathodus dieneri - 0..0' ...:I H "' ... 0 Neospathodus cristagalli ~;:3 "'p.. "'z E-::3 c. -R. -z. "'"'Vl Fig. I. Lower Triassic Conodont Zonal Standard and the possibilities of Permian-Triassic boundary definition Some genera: CI.=C/arkina; Ksh. = Kashmire/la; Scy. = Scythodondolella; Spi. = Spathoicriodus in the middle of this conodont zone and for this reason it cannot be accurately characterized by conodonts (Permian-Triassic boundary: 1st possibility on Fig. 2). The upper part of the Lower Griesbachian (Otoceras boreale Zone) and the lower part of the Upper Griesbachian (Ophiceras commune Zone) are well charac terized by Anchignathodus parvus Kozur & Pjatakova. The lower part of the men tioned interval, late Lower Griesbachian in age, is well separated with the aid of this 99 species exsluding Clark ina subcarinata (Sweet) and Isarcicel/a isarcica (Huckriede), and corresponds to Anchignathodus parvus 1.-Z. The appearance of Ophiceras commune Spath (Ophiceras tibeticum Griesbach in Kashmir) is related to the appearance of Isarcicella isarcica (Huckriede) and this marks the beginning of the Upper Griesbachian. Isarcicel/a isarcica R.-Z. is slightly exceeding the lower Upper Griesbachian. The uppermost Griesbachian (nearly the whole Proptychites strigatus Zone) is defined by C/arkina carinata A.-z., because it contains only forms of the conodont species of the same name. In fact, this is the most incompletely characterized inter val of the Lower Triassic in which conodonts of Paleozoic affinities already disap peared (Anchignathodus and/sarcice//a),and the typical Lower TriassicNeospathodus had not yet appeared. The disappearance of the representatives of genus Anchignathodus (including also genuslsarcicella which differs frornAnchignathodus only by the presence of one or several denticles on the upper surface of the widening of the basal cavity) is used by K o z u r (1980) as a possibility to fix the boundary Permian-Triassic. The disap pearance of the typical Paleozoic representatives of the genus Otoceras and some important ostracod genera is related also to this boundary. According to N e w e 1 1 (1978), the principal event the change of Paleozoic ammonite faunas by those Triassic taxa which must trace the boundary between the Paleozoic and the Triassic - occured at the base of Gyronites Zone. This event was noted also by T o z e r (1978) as event 3, but he did not stress its importance. Our conodont studies illustrate well the striking conodont change of Anchignathodus andlsarcicel/a by Neospathodus andKashmirel/a at the Griesbachian Dinerian boundary (Permian-Triassic boundary: 2nd possibility on fig. 2). If we take into account also the change in ammonitic faunas (New e 11, 1978; Tozer, 1978) it seems that we can place the Permian-Triassic boundary most convincingly there. Lower Triassic conodont zones Clarkina subcarinata-Anchignathodus typica/is Concurrent-Range-Zone Nomenclature. Introduced by Bud u r o v et al. (1987) as the Neogondolella subcarinata-Anchignathodus typicalis C.-R.-Z. in the uppermost parts of the Dorashamian and in the lowermost parts of the Griesbachian. Emended definition. Clarkina subcarinata-Anchignathodus typica/is C.-R.-Z., characterized by a part of the ranges of the species Clark ina subcarinata (Sweet) and Anchignathodus typica/is Sweet, with a very rare penetration into the lower part of Anchignathodus ju/fensis Sweet and without Anchognathodus parvus Kozur & Pjatakova, in the uppermost parts of the Dorashamian and in the lower parts of the Lower Griesbachian. Lower boundary. Set by the first appearance of Clarkina subcarinata (Sweet) and strong decrease of the number of Anchignathodus julfensis Sweet. Upper boundary. Seth with first appearance of Anchignathodus parvus Kozur & Pjatakova and the disappearance of Clarkina subcarinata (Sweet). Age. The uppermost parts of Dorashamian stage, equivalent to the ammonite Paratirolites Beds, and the lower parts of the Early Griesbachian stage, correspond ing to the Otoceras concavum Zone. Remarks. The conventional Permian-Triassic boundary is located in the midst of this conodont zone. This boundary area cannot, in our opinion, be accurately defined by conodonts, because the contained fauna has not signs of any evolutional 100 101 ., ciQ' LOWER TRIASSIC INDUAN OLENEKI AN N AGE AND AIII10NO I D ZONES .,;:c GRIESBACH! AN Dl£1~ERIAN SMITH IAN SPATH IAN ~ .; ::1 ~ ~ ;; 0 • ~." < ()Q a ~ ... ., §• ~ ~ A ~ • ~ ::r i. ~ - .[ ! ~ ~- 0: ~ ;::! ~ ~ 0..., .. ,.. ~l CONODONT SPECIES % b r , ol ~. oI ~~ ~ ~ a §~~n ~· ~ - ~ ~ ~ ~, ~, 0 ~ l ~ [. \ % ~- ~ - "' < ~ ~ ~ ~ ~ \ ~ ~ ~ ~ ~ ~q 3. 3 ~ [ :;l ;;;· Anchignathodus jul{ensis Sweet, 1973 r- Clorkina orienta/is ( Barskov & Koroleva, 1970) "'~- Clark/no corinoto (Clark, 1959) () Clor kino subcorinoto (Swee t , 1973 ) () 0 Anchignathodus typlcolis Sweet, 1970 ::1 ~- - Anchignothodus por111.1S lozur • Pjatakova, 1976 8. I-- lsorcicel/o lsarcico (H uc kTiede, 1958 ) 0 Neospothodus dieneri Sweet, 1970 ~ Koshmirello kummeli (Swee t, 19 70) "' r-1------1 Neosporhodus crlstogolli ( Huckriede, 1958) Neospothodus pok.istonensis Sweet, 1970 1- Kashmire//o nepolensis (lozu r I Mostler, 19 76) Koshmirello no'lloehollandioe (McTavish, 197.l) Heospothodus woageni Sweet, 1970 Smlthodus /ongiusculus (B uryi, 1979) Platyvil/osus costotus (Staesc he, 1964) -~ Furnischius triserrotus Clark, 1959 N~spo t hodus disc rf!tus (Muller, 1956) Porochirognolhus ethingtoni Clark, 1959 1------N~spothodus bronsoni (Muller, 1956) 1-- Bor inello nevodensis (C lark, 1959) Borinella buurensis ( Dagi5, 1984) Bar/nella elongata {Sweet, 1970) KashmiN!!flo olbertil Budurov, Sudar & Gupta, 1988 Neospothodus bicuspidorus (Mu 11 er, 1956) - Neospothodus conservativus ( Mu 11 e r , 1956) --t:t Scythogondolello milleri ( Muller, 1956) KashmiN!!flo zoksl ( Buryi, 1979) Koshmlreflospothi (Sweet, 1970) N~spothodus triangularis (Bender, 1970) a Spothoicriodus collinsoni (So lit!n, 1979) Plotyvlffosus osperotus Clark, Sine. & Stone, 1964 IE ;:':;~:11:a:u::::e ~~:::::h~; ,::••l 1--+--....j--j NI!Ospothodus hommeri (Bender, 1970) Borinello toymirPnsis (D.lgis , 1984) Borinello she~yrevi . (Kozur &_Mostler, 1976) , , , , , , , , I. , • t§~ Koshmlrello t1mor ens1s ( Noga111, 1968) Ilr-~---+l-- --~~Ill-,_------r.II~~------~-i--! 4-~I ----~--+--- · ~ " , .. ~ ~ n ' ~ . 2: ~ , ~ ~ ~ ~ ~ > 'g ~ ~ ~ ~ -g ~ ~ 2 2 ·. .2 Q. ~ . 0 ~ - N ~ • & ~ ~ 5 ~ ~ z 0. n ii i io· -. ~ 0 ~ ~ ~ H ~ 5 - s· 5 J ~ "ti ~ ~ ~ ~ • 0 g· Cl n o. . , i a- §. lY ~ I .' "'< ~ } ! ~ l~ ~ 3. ~ a. ~ ~ - : ~ :.. ~ - :::: ~ ;.. ;.. ;.. ~ variation; even reliable data are inadequate to prove that any species began or termi nated its existence in this area. These were the reasons why we had to extend this zone to include both the upper-most Upper Permian and the lowermost Early Trias sic. Anchignathodus parvus Interval-Zone Nomenclature. Introduced by K o z u r & Most 1 e r (1973, p. 3) as Anchignathodus parvus A.-Z. in the "Ophiceras commune Zone ausser deren basalen Teil". Emended deginition. Anchignathodus parvus I.-Z. characterizing the interval of the occurence of Anchignathodus parvus Kozur & Pjatakova without Clarkina subcarinata (Sweet) and Isarcicella isarcica (Huckriede) in the upper parts of the Lower Griesbachian. Lower boundary. Set by the appearance of Anchignathodus parvus Kozur & Pjatakova and the disappearance of Clarkina subcarinata (Sweet). Upper boundary. Set with the first appearance oflsarcicella isarcica (Huckriede). Age. The upper parts of the Lower Griesbachian stage, equivalent to ammonite zone Otoceras boreale. Isarcicella isarcica Range-Zone Nomenclature. Introduced by Kozur & Mostler (1973, p. 6) as Anchignathodus isarcicus-Zone in the "Basale Ophiceras commune-Zone". Emended definition. Isarcicella isarcica R.-Z. characterizing the range of Isarcicella isarcica (Huckriede) in the Late Griesbachian. Boundaries. Set by the appearance and the disappearance of Isarcicella isarcica (Huckriede). Age. The Upper Griesbachian equivalent to ammonite zones Ophiceras com mune and Proptychites strigatus. Clarkina carinata Assemblage-Zone Nomenclature. Introduced by Sweet (1970) as the zone ofNeogondolella carinata (Zone 2) in the lower parts of the Lower Triassic of West Pakistan. Emended definition. Clarkina carinata A.-Z. characterizing range interval of Clarkina carinata (Clark) without Isarcicella isarcica (Huckriede), Kashmirella kummeli (Sweet) and Neospathodus dieneri Sweet in the uppermost parts of Upper Griesbachian. Lower boundary. Set by the local disappearance of Isarcicella isarcica (Huckriede) and Anchignathodus parvus Kozur & Pjatakova. Upper boundary. Set with the first appearance of Kashmirella kummeli (Sweet) and Neospathodus dieneri Sweet. Age. A wery short interval of the uppermost parts of Late Griesbachian stage (=corresponding to the uppermost parts of ammonites zone Proptychites strigatus). Remarks. In conformity with the earlier statement, this zone is confined to a very short interval of the uppermost Upper Griesbachian, where no other conodont but Clarkina carinata (Clark) is commonly believed to have exsisted, because the fauna with Paleozoic features (Anchignathodus, Isarcicella) disappeared, and repre sentatives of typical Early Triassic conodont genera, Neospathodus and Kasmirella, not yet appeared. This small gap will certainly be filled in the future, as our investi gation has confirmed that the distribution ofIsarcicella isarcica (Huckriede) con tin- 102 ued to the end of the Griesbachian, to the first appearance of Kashmirella kummeli (Sweet) andNeospathodus dieneri Sweet. This is certainly a significant argument that this zone should not be separated in future conodont zonations, as some authors alreaby accepted (e. g. Carr & Paull, 1983; Sweet & Bergstrom, 1986; Sweet, 1988, etc.). Until the present dilemmas have been cleared, and in this paper, we accepted this zone's existence only tentatively and only in the terms of its earlier separation (e. g. Sweet et al., 1971, etc.), but of a restricted regional importance-, shorter ver tical range, and with inadequately defined boundary relationship with the preceding zone. Conodont successions of the Dienerian Stage The beginning of the Dienerian Stage (Proptychites candidus Zone) is marked by th~ most striking Lower Triassic conodont appearance of genera Neospathodus and Kashmire/la (Fig. 1). Its radiation, apart from the Lower Triassic, affects also the base of the Anisian. It is well known (S w e e t et al., 1971) that the Dienerian stratig raphy is based on the taxaKashmirella kummeli(Sweet),Neospathodus dieneriSweet and Neospathodus cristaga/li (Huckriede). On the basis of literature data and our conodonts collected in Kashmir we propose the following: 1. The range of Kashmirella kummeli (Sweet) is very narrow and is not equiva lent to the range of Proptychites candidus Zone, only to its lowermost parts. This is a biomarker horizon of very small thickness in the field but of fundamental strati graphic importance. 2. The conodonts Neospathodus dieneri Sweet and Neospathodus ctistagalli (Huckriede) appear together at the base of the Dienerian. These two taxa, after the disappearance of Kashmirella kummeli Sweet, remain the only key fossils for the Dienerian Stage. Our biometric studies of over 250 specimens of the two species show very similar data, particularly for the young individuals (similar results are reported by M a t s u d a, 1982). As a rule they appear together in the same samples. For the time being we cannot decide wether they are two different taxa or two sub species of Neospathodus cristaga/li (Huckriede). For this reasons the two zones pro posed by Sweet et al. (1971) Neospathodus dieneri andNeospathodus cristagalli for the upper part of Proptychites candidus - and Vavilovites svedrupi Zone are practically undistinguishable. We suggest a subdivision of the Dinerian Stage into two zones: Kashmirella kummeli R.-Z., based of the range of this taxon, and Neospathodus dieneri Neospathodus cristagalli C.-R.-Z. withoutKashmirella kummeli Sweet, based on the concurrent range of the two taxa. Kashmirella kummeli Range-Zone Nomenclature. Introduced by Sweet (1970) as the Zone of Neospathodus kummeli (Zone 3) in the lower parts of the Lower Triassic of West Pakistan. Definition. Kashmirella kummeli R.-Z. characterising the range of Kashmirella kummeli (Sweet) in the lowermost parts of the Dienerian. Boundaries. Set with the local appearance and disappearance of Kashmirella kummeli (Sweet). Age. The lowermost parts of the Dienerian Stage, equivalent to the lower parts of Proptychites candidus ammonite zone. Remarks. The speciesKashmirella kummeli (Sweet) has, according to the inves tigations data, a restricted regional distribution within the Tethyan-Pacific conodont 103 area (e. g. the Himalaya, and probably also Australia, and Siberia). This neither al lows the establishment of any new or special relations leading to a subdivision within the mentioned province, nor diminishes the importance of the zone as "a biomarker horizon of very small thickness in the field but of fundamental stratigraphic impor tance" (B u d u r o v et al., 1988, p. 326), and future studies will certainly extend the perimeter of its regional distribution. Neospathodus dieneri-Neospathodus cristaga/U Concurrent-Range-Zone Nomenclature. Introduced by Bud u r o v et al. (1987, 1988) as the zone of the same name in the almost whole interval of the Dienerian. Emended definition. Neospathodus dieneri-Neospathodus cristagalli C.-R.-Z. characterizing concurrent ranges of the species Neospathodus dieneri Sweet Neospathodus cristaga/U (Huckriede) without Isarcicella isarcica (Huskriede), Kashmirel/a kummeli (Sweet),Neospathodus waageni Sweet andKashmirella nepalensis (Kozur & Mostler) almost through the Dinerian. Lower boundary. Set by the first appearance of Neospathodus dieneri Sweet without Isarcicella isarcica (Huckriede) and Kashmirella kimmeli (Sweet). Upper boundary. Set with the disappearance of Neospathodus cristagalli (Huckriede) and appearance of Kashmirella nepalensis (Kozur & Mostler) and Neospathodus waageni Sweet. Age. Nearly all of the Dienerian stage, equivalent to the ammonite zones Proprychites candidus and Vavilovites svedrupi (except their uppermost parts). In areas of identified Kashmirella kummeli L.-R.-Z., the vertical range of the zone is decreased for the :lowermost parts of the Dienerian, corresponding to the identical parts of Proptychites candidus ammonite zone (figs. 1, 2). Conodont successions of the Smithian Stage As a rule the boundary between the Dienerian and Smithian Stages should be refined by ammonite experts. On the basis of conodonts we can place this boundary at the appearance of the narrow and very characteristic biomarker horizon withKashmirella nepalensis (Kozur & Mostler) which corresponds to lowermost part ofEujlemingites rominderi Zone. The remaining part of this zone and the range of Wasatchites tardus Zone are well characterized by Neospathodus waageni Sweet. We propose to repiaceNeospathodus pakistanensis withKashmirella nepa/ensis R.-Z. for the following reason: Kashmirella nepalensis (Kozur & Mostler), though known until now from the Asiatic localities, is a taxon whish can be easily identified and has a very narrow stratigraphic range. Facies-control lead to parallel development of conodont faunas Parachi rognathus-Furnishius and in the upper part of the Smithian was responsible for the occurrence of a persistent level based on the range ofScythogondolella milleri (Muller). Kashmirella nepalensis Range-Zone Nomenclature. Although it was stated (Bud u r o vet al., 1989) that, in our opinion, this zone was introduced by the authors of the species of the same name by writing: "Die erste Art is in der Conodontenzonierung die Zonenindexart des basalen Jakutian" (K o z u r & Most I e r, 1976, p. 23), it should be specified that the mentioned au- 104 thors quoted earlier and described this stratigraphic interval as a separate zone but under undefined specific name "Zone mit N. gen. n. sp. 1" (K o z u r & Most 1 e r, 1972, p. 784), or "Zone mit Gondolella n. sp. B" (K o z u r & Most 1 e r, 1973, p. 8). Definition. Kashmire/la nepalensis R.-Z. characterizing the range of the index species in the uppermost parts of the Dienerian, and the lower parts of the Smithian. Boundaries. Set by the appearance and the disappearance of Kashmirella nepalensis (K o z u r & Most 1 e r). Age. The uppermost parts of the Dienerian Stage ( = corresponding to parts of the ammonite zone Vavilovites svedrupi), and the lower parts of the Smithian stage, equivalent to the lower parts of Euflemingites romunderi Zone. The zone is correlated with the lower parts of the Parachirognathus-Furnishius Beds of the facially-controlled zones (Figs. 1, 2). Remarks. Although the index species of the zone has a somewhat restricted regional distribution in the Tethyan-Pacific conodont area (Figs. 1, 2), the reasons for its separation instead of Neospathodus pakistanensis Zone, as we used to do (Bud u r o vet al., 1983, 1985), or as many autors still (e. g. Sweet, 1970; Sweet et al., 1971 ; Matsuda, 1981,1985; Eypuii:, 1979; etc.), has been discussed in B u d u r o v et al., 1988. Neospathodus waageni Assemblage-Zone Nomenclature. Introduced by Sweet (1970) as Zone of Neospathodus waageni (Zone 7) in the upper parts of the Lower Triassic of West Pakistan. Emended definition. Neospathodus waageni A.-Z. characterizing the range in terval of Neospathodus waageni Sweet, without Kashmirella nepalensis (Kozur & Mostler) and Neospathodus triangularis (Bender) in the middle and upper parts of the Smithian. Lower boundary. Set by the appearance of Neospathodus waageni Sweet with out Kashmirella nepalensis (Kozur & Mostler). Upper boundary. Set with the first appearance of Neospathodus triangularis (Bender). Age. Almost the whole Smithian stage, equivalent to the upper parts of the am monite zone Eujlemingites romunderi and the entire Wasatchites tardus zone. The zone is correlated with the following facies-controled zones; with nearly the whole of the Parachirognathus-Furnishius Beds interval, or, in the upper levels, with the Scythogondolella milleri L. R.-Z. (Figs. 1, 2). Parachirognathus-Furnishius Beds Nomenclature. Introduced by Sweet et al. (1971) as Zone 7 (Parachirognathus Furnishius Zone) in the lowest Smithian (or "Meekoceras") of the Western United States (Utah, Nevada). Emended definition. Parachirognathus-Furnishius Beds characterizing the range interval of the Parachirognathus-Furnishius conodont fauna in the Smithian. Lower boundary. Set with the appearance of elements of the Parachirognathus Furnishius conodont faunas. Upper boundary. With regard to the possible occurence of the species Scythogondolella milleri (Muller), the upper boundary of this interval can be deter mined alternatively: either in the Late Smithian, with the appearance of Scythogondolella-milleri(Miiller), or somewhat later, at the Smithian Spathian bound ary, with the disappearence of Parachirognathus-Furnishius conodont fauna. 105 Age. The uppermost parts of the Dienerian stage ( = corresponding to parts of the ammonite zone Vavilovites' svedrupl), and the Smithian Stage, equivalent to the ammonite zones Eujlemingites romunderi and Wasatchites tardus, except where Scythogondolella milleri R.-Z. can be separated, when its range is reduced for the uppermost zone Wasatchites tardus, of the Upper Spathian. The interval is correlated with the Kashmire/la nepalensis R.-Z. (in the lower most parts), and with Neospathodus waageni A.-Z. (in the middle and upper parts) (Figs. 1, 2). Scythogondolella mil/eri Range-Zone Nomenclature. Introduced by Sweet et al. (1971) as Zone 9 (Neogondolella mi/leri Zone) in the uppermost parts of the Smithian in the western United States. Emended definition. Scytogondolella milleri R.-z. characterizing the range of Scythogondolel/a milleri (Muller) in the uppermost parts of the Smithian. Boundaries. Set with the appearance and the disappearance of Scythogondolella milleri (Muller). Age. The uppermost parts of the Smithian Stage, equivalent to Wasatchites tardus Zone (only the uppermort levels). The zone is correlated with the uppermost parts of the Neospathodus waageni A.-Z., and Parachirognathus-Furnishius Beds (Fig. 1, 2). Conodont successions of the Spathian Stage and the Lower-Middle Triassic boundary The youngest, Spathian Stage of the Lower Triassic has been repeatedly proven by conodonts. Sweet et al. (1971) suggested a subdivision into two conodont zones: Neogondolella jubata (= Borinella jubata) and Neospathodus timorensis. Since the distribution of Borinellidae is facies-controlled they are not of general occurence. In contrast, Neospathodus triangularis (Bender) and Neospathodus homeri (Bender) are found everywhere. Though with small difference at the time of appearance they form a zone (Assemblage Zone) of the same name with stratigraphic range: "Olenikites" pilaticus the lower parts of Keyserlingites subrobustus Zone. We are of the opinion that the use of this zone is more accurate and suggest replacing Borinella jubata Zone. Where the facies-control was favourable this interval may be further subdi vided into three intervals in which Borinella jubata is present: lower beds with Platyvillosus and Foliella, middle- defined by the range of Spathoicriodus collinsoni Solien and upper - with Borinella jubata (Sweet), acompanied by Neospathodus triangularis (Bender) and Neospathodus homeri (Bender). The appearance of Kashmirella timorensis (Bender) is related to fauna which correlates with the upper part of Keyserlingites subrobustus Zone.The disappear ance of this taxon marks the boundary between the Lower and the Middle Triassic. Neospathodus triangularis-Neospathodus homeri Assemblage-Zone Nomenclature. Introducted by Bender /1970 (1968)/ as homeri-Zone; its lower part, defined as "untere homeri-Zone" and "unterer Abaschnitt mit Spathognathodus triangularis", is added to "Oberskyth (Campiler Schichten)" fB end e r, 1970 (1968), Tab. 1, p. 469/. Emended definition. Neospathodus triangularis-Neospathodus homeri A.-Z. char acterizing the interval of the coincident ranges of the speciesNeospathodus triangularis 106 (Bender) andNeospathodus homeri(Bender) withoutKashmirella timorensis(Nogami) in the lower and middle parts of the Spathian. Lower boundary. Set by the first appearance of Neospathodus triangularis (Bender). Upper boundary. Set with the appearance of Kashmirella timorensis (Nogami). Age. The lower and the middle parts of the Spathian stage, equivalent to the nameless(?) ammonite interval and "Keyserlingites" pilaticus ammonite Zone (see Figs. I, 2 - Ammonoid zones of Canada). The lower parts of this zone is correlated with the Platyvillosus-Foliella Beds, and the middle parts with theSpathoicriodus collinsoni (Solien). All mentioned zones are ecology and facies controlled (Figs. 1, 2). Remarks. The upper parts of this zone have been refered to a Borinella jubata A.-Z. Due to the ubiquitous occurence of Neospathodus triangularis (Bender) and Neospathodus homeri (Bender) including in the region where our facies-controlled zone has been earlier defined, we accept now the definition of this interval by the mentioned two taxa. Platyvillosus-Foliella Beds Nomenclature. Introduced by Sweet et al. (1971) as Zone 10 (Platyvillosus Zone) with the oldest Spathian conodont fauna from the western United States. Emended definition. Platyvillosus-Foliella Beds characterizing the vertical oc currence of the Platyvillosus-Foliella conodont fauna in the Early Spathian. Boundaries. Set with the appearance and the disappearance of elements of the Platyvillosus-Foliella conodont fauna. Age. The lower parts of the Spathian Stage, equivalent to the lower levels of Tirolites-Columbites Beds (after D a g i s, 1985, for the Tethys realm), or to the indetermined (?)ammonite zone of Canada (Figs. I, 2; Tozer, 1967, emended by D a g i s, 1985). The interval is correlated with the lower parts of the Neospathodus triangularis Neospathodus homeri A.-Z. (Figs. 1, 2). S pathoicriodus collinsoni Assemblage-Zone Nomenclature. Introduced by S w e e t et al. ( 1971) as Zone 11 in the upper parts of the Lower Spathian and stabilized by S o l i en (1979) as Range Zone II (Neospathodus collinsoni Zone) with a shorter stratigraphic interval of the same age. Emended definition. Spathoicriodus collinsoni A.-z. characterizing the range interval of Spathoicriodus collinsoni (Solien) without elements of the Platyvillosus Foliella conodont fauna in the middle parts of Spathian. Lower boundary. Set by the disappearance of forms ofthePiatyvillosus-Foliella conodont fauna. Upper boundary. Set by the disappearance of Spathoicriodus collinsoni (Solien). Age. The middle parts of the Spathian Stage, equivalent to the upper !eves of the Tirolites-Columbites Beds (after Dagis, 1985, for the Tethys realm). The zone is correlated with the middle parts of the Neospathodus triangularis Neospathodus homeri A.-z. (Figs. 1, 2). Kashmirella timorensis Range-Zone Nomenclature. Introducted by Bud u r o v in Bud u r ov & Tr i fo nov a (1974, p. 59) as gondolelloides-Zone alp in the "obere Teile des Hydasps". 107 Emended definition. Kashmirella timorensis R.-Z. characrerizing the range in terval of Kashmire/la timorensis (Nogami) in the upper parts of the Spathian. Boundaries. Set by the appearance and the disappearance of Kashmire/la timorensis (Nogami). Age. The upper parts of the Spathian stage, equivalent to ammonite zone Keyserlingites subrobustus. Remarks. Until recently, we used to admit a wide variability of the species Kashmirella gondolelloides (Bender), and consequently, a nomenclature priority of this species upon Kashmirella timorensis (Nodami). Therefore, the latter has been included within the volume of Kashmirella gondole/loides (Bender). New observa tions on faunistic sequences in Bulgaria and Yugoslavia sonvinced us in the indepen dence of the two species. Each of them has an own biostratigraphic value: Kashmirella timorensis (Nogami) occurs in the upper parts of the Spathian, and Kashmirella gondolelloides (Bender), in the lowermost Aegean. Each of the two taxa defines a zone based upon its range. The Kashmire/la timorensis R.-Z. is considered for the first time in the abovementioned volume in the present paper. • • • The following conclusions can be drawn on the basis of problems discussed: -No conodont provincialism existed during the Early Triassic. The conodont content has been almost uniform within the unique then existing Tethys-Pacific con odont area, all zones described in the present paper are valid for it. - The conodont zones defined give a complete characteristics of the Lower Triassic stages and substages. Facies-controlled zones are related to a number of ecological factors. References Bender, H. 1970 (1968). Zur Gliederung der mediterranen Trias II. Die Conodontenchronologie der mediterranen Trias.- Ann. Geol. Pays Helleniques, T-XIX-1968-A; 465-540. Budurov, K. J., Gupta, V. J., Kachroo, R. K., Sudar, M. N. 1986. Problems of the Lower Triassic Conodont Stratigraphy and the Permian(friassic boundary (Abs.). - Field Conf. "Permian and Permian-Triassic boundary in the south-alpine segment of the western Tethys, and addditional repons" (Brescia, 4-12 July 1986), Abstracts, Soc. Geol. Ita., IGCP Project 203; 19. Bud u r o v, K. J., Gupta, V. J., K a c h roo, R. K., Sud a r, M. N. 1987. Problems of the Lower Triassic Conodont Stratigraphy and the Permian-Triassic boundary. - Jour. Geol. Soc. In dia, 30; 80-81. Bud u r o v, K. J., Gupta, V. J., K a c h roo, R. K., Sud a r, M. N. 1988. Problems of the Lower Triassic Conodont Stratigraphy and the Permian-Triassic boundary. -Mem. Soc. Geol. /tal., 34 (1986); 321-328. Bud u r o v, K. J., Gupta, V. J., Sud a r, M. N., Bury i, G. I. 1983. Triassic Conodont Biofacies and Provinces. -Bull. ndian Geol. Assoc. /6, I; 87-92. Bud u r o v, K. J., Gupta, V. J., Sud a r, M. N., Bury i, G. I. 1985. Conodont zonation, biofacies and provinces in the Triassic. - Jour. Geol. Soc. India, 26, 2; 84-94. Bud u r o v, K. J., Sud a r, M. N., G up at a, V. J. 1989. Early Triassic Parallel Conodont Zondtion. Contribution to Himalayan Geology, 4; 158-166. Bud u r o v, K., T r if on ova, E. 1974. Die Conodonten- und Foraminiferen-Zonen in der Trias des Ostbalkans. In Zapfe, H. (ed.): Die Stratigraphie der alpinmediterranen Trias. - Schriftenr. Erdwiss. Komm. Osterr. Akad. Wiss., 2; 57-62. Carr, T. R., P a u II, R. K. 1983. Early Triassic stratigraphy and paleogeography of the Cordillerian miogeocline.- In M. W. Reynolds and E. D. Dolly (eds.): Mesozoic Paleogeography of the West-Central United States; 39-55. 108 D a g is. A. S. 1985. Comments on the subdivision of the Lower Triassic. - Albertiana. 4; 17-19. K o z u r, H. 1980. The main events in the Upper Permian and Triassic conodont evolution and its bearing to the Upper Permian and Triassic stratigraphy.- Riv. !tal. Paleont. Strat., 85. 3-4; 741-766. K o z u r, H., Most I e r, H. 1972. Die Bedeutung der Conodonten fiir stratigraphische und paHiogeographische Untersuchungen in der Trias. - Mitt. Ges. Geol. Bergbaustud. , 21. 2; 777-810. K o z u r, H ., M o s t I e r. H . 1973. Beitriige zur Mikrofauna permotriadischer Schichtfolgen. Teil I: Conodonten aus der Tibetzone des Niederen Himalaya (Dolpogebiet, Westnepal). - Geol. Palaont. Mitt. lnnsbruck, 3, 9; 1-23. K o z u r, H., M o s t I e r, H. 1976. Neue Conodonten a us dem Jungpaliiozoikum und der Trias. - Geol. Palaont. Mitt. lnnsbruck, 6, 3; 1-33. M a t s u d a, T. 1981 . Early Triassic Conodonts from Kashmir, India. Part I: Hindeodus and Isarcicella. -Jour. Geosci., Osaka City Univ .. 24, 3; 75-108. Matsuda, T. 1982. Early Triassic Conodonts from Kashmir, India. Part 2: Neospathodus 1. -Jour. Geosci., Osaka City Univ., 25,6; 87-102. Matsuda, T. 1985. Late Permian to Early Triassic Conodont Paleobiogeography in the "Tethys Realm". - In K. Nakazawa & J. M. Dickins (eds.): The Tethys. - Her Paleogeography and Paleobiogeography from Paleozoic to Mesozoic; 157-170. New e II, N. D. 1978. The search for a Paleozoic-Mesozoic Boundary Stratotype. In H. Zapfe (ed.) Beitriige zur Biostratigraphie der Tethys-Trias. -Schr. Erdwiss. Komm., Osterr. Akad. Wiss., 4; 9-19. So I i en, M. A. 1979. Conodont biostratigraphy of the Lower Triassic Thaynes Formation, Utah. - J. Paleont., 53. 2; 246-306. Sweet, W C. 1970. Uppermost Permian and Lower Triassic Conodonts of the Salt Range and Trans· Indus Ranges, West Pakistan.- In : B. Kummel & C. Teichert (eds): Stratigraphic boundary problems: Permian and Triassic of West Pakistan. - Univ. Kansas. Dept. Geol. Spec. Pub/., 4; 207-275. Tozer, E. T. 1978. Review of the Lower Triassic Ammonoid Succession and its Bearing on Chro~ost~atigraphic Nome~clature. - In: H. Zapfe (ed._): Bei~riige zur Biostratigraphie der Tethys-Tnas.- Schr. Erdw1ss. Komm.. Osterr. Akad. W1ss., 4, 21-36. Sweet, W C. 1988. A quantitative conodont biostratigraphy for the Lower Triassic. - Senckenberg. /ethea, 69, 3/4; 253-273. Sweet, W C. Bergstrom, S.M. 1986. Conodonts and biostratigraphic correlation. - Ann. Rev. Earth Planet Sci., 14; 85-112. Sweet, W C., Mosher, L. C., Clark, D. L., Collinson, J. W, Hansenmuller, W A. 1971. Conodont Biostratigraphy of the Triassic. In W C. Sweet & S.M. Bergstrom (eds): Symposium on Con· odont Biostratigraphy. - Geol. Soc. America, Mem .. 127; 441-465. Tozer, E. T. 1967. A standard for Triassic time. - Geol. Surv. Canada. Bull. . 156; 1-103. 0 y p I! H, r. 11. 1979. HU::HCHempuaC06ble KOHoOOHmbl lO::HCHOi!O JlpUMOpbll . HHCT. reon. reo4>1!3., Cu6upcKoe OT.ll., AKa.a. HayK CCCP /H3.1X. ,HayKa"f; 142 c. 109 u Vl~ candidus frequens z Ksh . kummeli R.-~ < ~ :::> Proptychites - Cl. carinata A.-Z/ ~ - ...>- z strigatus ~ - >- ..... H ... -- ...:I C.: ..... z lsarcicella isarcica R.- Z. << ..... < Ophiceras Ophiceras z~ H oz .c..... :I: commune tibeticum >-<:::> u E-0 < H