short polarity intervals corresponding to the tiny wiggles which, upon calibration, convert to durations of less than 30 ky. In view of their uncertain origin, these globally mapped geomagnetic features are referred to as cryptochrons and have not been included in any of these charts. Cande and Kent (1995) generated an adjusted geomagnetic reversal chronology for the late Cretaceous and Cenozoic using the same tiepoints and anomaly distances as CK92 except in two instances: a) a consensus age of 65 Ma (rather than 66 Ma in CK92) was used for the Cretaceous/Paleocene boundary in Chron C29r; and b) a tiepoint at 5.23 Ma for the older boundary of Subchron C3n.4n was used rather than 2.60 Ma for the younger boundary of Chron C2An. The latter modication allowed the direct incorporation of the astrochronologically calibrated polarity time scale for practically all of the Pleistocene and the Pliocene that was developed by Shackleton et al. (1990) and Hilgen (1991) and thereby avoided the promulgation of separate timescales over this interval (see discussion in Berggren et al., 1995a). The revised geomagnetic polarity time scale (CK92/95, or sometimes just CK95) was used as the chronological framework for the integrated Cenozoic time scale of Berggren et al. (1995b).

SELECTED REFERENCES

BERGGREN, W. A., KENT, D. V., FLYNN, J. J. AND VAN COUVERING, J. A.,1985, Cenozoic geochronology: Geological Society of America Bulletin, 96, 1407 1418. BERGGREN, W. A., HILGEN, F. J., LANGEREIS, C. G., KENT, D. V., OBRADOVICH, J. D., RAFFI, I., RAYMO, M. E., AND SHACKLETON, N. J., 1995b, Late Neogene chronology: New perspectives in high-resolution stratigraphy, Geological Society of America Bulletin, v. 107, p. 12721287. BERGGREN, W. A., KENT, D. V., OBRADOVICH, J. D. AND SWISHER, C. C. III, 1992, Toward a revised Paleogene Geochronology, in PROTHERO, D. R., AND BERGGREN, W. A., eds., Eocene-Oligocene Climatic and Biotic Evolution: Princeton University Press, Princeton, N. J., p. 2945. BERGGREN, W. A., KENT, D. V., SWISHER, III, C. C., AND AUBRY, M.-P., 1995, A revised Cenozoic geochronology and chronostratigraphy, in Berggren, W. A., Kent, D. V., Aubry, M.-P., and Hardenbol, J., eds., Geochronology, Time scales and Global Stratigraphic Correlation: Tulsa SEPM Special Publication 54, p. 129212. CANDE, S. C., AND KENT, D. V., 1992a, A new geomagnetic polarity time scale for the Late Cretaceous and Cenozoic: Journal of Geophysical Research, v. 97, p. 1391713951. CANDE, S. C., AND KENT, D. V., 1992b, Ultrahigh resolution marine magnetic anomaly proles: A record of continuous paleointensity variations?: Journal of Geophysical Research, v. 97, p. 15,07515, 083. CANDE, S. C., AND KENT, D.V., 1995, Revised calibration of the geomagnetic polarity time scale for the LateCretaceous and Cenozoic: Journal of Geophysical Research, v. 100, p. 60936095. HEIRTZLER, J. R., DICKSON, G. O. HERRON, E. M. PITMAN, W. C. III, AND LEPICHON, X. 1968, Marine magnetic anomalies, geomagnetic eld reversals, and motions of the ocean oor and continents: Journal of Geophysical Research, v. 73, p. 21192136. HILGEN, F. J. , 1991, Extension of the astronomically calibrated (polarity) time scale to the Miocene/Pliocene boundary: Earth Planetary Science Letters., v. 107, p. 349368. SHACKLETON, N. J., BERGER, A. AND PELTIER, W. R., 1990, An alternative astronomical calibration of the lower Pleistocene timescale based on ODP Site 667: Transactions Royal Society of Edinburgh, Earth Science., v. 81, p. 251261.

PLANKTONIC FORAMINIFERA

William A. Berggren Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
Mesozoic and Cenozoic Sequence Stratigraphy of European Basins, SEPM Special Publication No. 60 Copyright 1998, SEPM (Society for Sedimentary Geology), ISBN 1-56576-043-3
APPENDIX Jamaica (Aubry,1993 Berggren,1993 and Miller et al., 1994) for the Miocene. The reader is referred to Berggren et al., (1995a,b) for the details on magnetobiostratigraphic correlations in these sections. The calibration of Pliocene and Pleistocene calcareous nannofossil datums in Berggren et al. (1995b) is based on the studies of Backman and Shackleton (1983), Backman and Pestiaux (1987), Berggren et al. (1983). It appears there remain two main problematic stratigraphic intervals. Middle Eocene datums are poorly tied to the magnetic reversal pattern due to the lack of continuously recovered and (temporally) complete sections. Upper middle and lower upper Miocene datums (NN7-NN10 zonal interval) are unsatisfactorily tied to the magnetic polarity pattern because of unprecedented inconsistent correlations between calcareous microfossil (calcareous nannofossil and planktonic foraminifera) datums and magnetozones in different sections (see also Aubry, 1997). For this reason, two sets of magnetobiostratigraphic correlations are given for the NN7- NN10 zonal interval. Oligocene diachrony between high and mid-low latitudes is now well-established as a result of drilling in he Southern Ocean, and this is reected in the magnetostratigraphic correlations as well.
REFERENCES CITED CAN BE FOUND IN
Calibration of planktonic foraminiferal datum events/zonal boundaries to the GPTS has been made essentially using the same DSDP and ODP sites/holes as reviewed below by Aubry. All datum events compiled in Berggren et al. (1985) have been reviewed and updated as well as all datum events identied and correlated to magnetostratigraphy in the 10 year interim to 1995. A major advance has been made in the compilation, and calibration, of Pliocene-Pleistocene datum events. The Achilles heel of this scheme remains, as for the calcareous nannoplankton, the middle Eocene, where lack of continuous, temporally complete stratigraphic sections precludes accurate magnetobiostratigraphic correlations. The Paleogene planktonic foraminiferal zonation follows that established by Berggren and Miller (1988); the Miocene zonal scheme is taken from Berggren et al. (1995), and the Pliocene Pleistocene is taken from Berggren et al. (1995b).

APPENDIX The calibration of the magnetic polarity scale to Cretaceous stage boundaries remains uncertain due to lack of agreement for placement of international stage boundaries by the Subcommission on Cretaceous Stratigraphy (e.g., Rawson et al.,1996). The magnetic time scale shown on the chronostratigraphic charts is according to pre-1993 common usage biostratigraphic markers for stage boundaries (reviewed in Ogg, 1995, and Gradstein et al., 1994). There have not been any precise ammonite or nannofossil markers for the Valanginian/Hauterivian boundary in magnetostratigraphic sections, and the observed variability in a dinoagellate marker for the boundary (last appearance datum of Scriniodinium dictyotum) brackets polarity zone M10Nr. However, Channell et al. (1994) have reported a possible occurrence of Acanthodiscus radiatus in an Italian section that would place the ammonite-dened Valanginian-Hauterivian boundary near the base of polarity zone M11n. The regional Purbeck stage of southern England has yielded a magnetostratigraphy consistent with an age assignment to polarity chrons M19r through M14r, indicating correlation to latest Tithonian through earliest Valanginian stages of the Tethyan realm (Ogg et al., 1994). The underlying Portland appears to span only polarity zones M21r through M19n, implying a middle and late Tithonian age correlation (Ogg et al., 1994).

PRINCIPAL REFERENCES

Program, Science Results, College Station, TX, Ocean Drilling Program, v. 115, p. 433463. FOURTANIER, E., 1991, Paleocene and Eocene diatom biostratigraphy and taxonomy of eastern Indian Ocean Site 752, in Weissel, J., Pierce, J., Taylor, E., Alt, J., et al., Proceedings of the Ocean Drilling Program, Science Results, College Station, TX, Ocean Drilling Program, v. 121, p. 171187. STRELNIKOVA, N. I., 1990, Evolution of diatoms during the Cretaceous and Paleogene periods, in Simola, H., ed., Proceedings of the Tenth International Diatom Symposium, Koenigstein, Germany, Koeltz Scientic Books, p. 195204. MESOZOIC ERA
James G. Ogg Mesozoic Stratigraphy Lab., Dept. Earth and Atmospheric Sciences, Civil Building 1397, Purdue University, West Lafayette, Indiana 479071397, U.S.A. e-mail: jogg@purdue.edu

Introduction

The Mesozoic portion of the magnetic polarity time scale was compiled from selected publications. Magneto-biostratigraphic studies published prior to 1993 were compiled by Ogg (1995). A version of that magnetic polarity scale with modications derived from publications through early 1994 was incorporated in the Mesozoic time scale of Gradstein et al (1994,1995) after rescaling to the durations of ammonite zones or subzones. In cases where the ammonite-zonal control is less complete (e.g., Sinemurian), then the observed pattern is scaled within the stage. This Gradstein et al (1994) version has been used on the chronostratigraphic charts of this volume. The following review briey summarizes revisions of the compilation of Ogg (1995) incorporated on the chronostratigraphy charts and indicates a few additional magnetostratigraphy studies of late 1994 through 1996 that are not included on the charts. The magnetic polarity time scale for the Mesozoic is well-documented in the Cretaceous and latest Jurassic where the seaoor magnetic anomaly pattern provides a guide for scaling the polarity sequence. The polarity pattern is known in partial detail for two-thirds of the Triassic and Jurassic ammonite zones. The major stages with ill-dened, inadequately calibrated or unresolved magnetic polarity patterns are the Carnian, Rhaetian-Hettangian-Sinemurian, and late Bathonian-Callovian. This magnetic polarity time scale will continue to be enhanced with further high-resolution magnetostratigraphy research.

CHANNELL, J. E. T., CECCA, F., AND ERBA, E., 1994, Correlations of Hauterivian and Barremian (Early Cretaceous) stage boundaries to polarity chrons: Eos, Transactions American Geophysical Union, v. 75 (1994 Fall Meeting Supplement), p. 202. OGG, J. G., HASENYAGER II, R. W., AND WIMBLEDON, W. A., 1994, JurassicCretaceous boundary: Portland-Purbeck magnetostratigraphy and possible correlation to the Tethyan faunal realm: Geobios, M.S. v. 17, p. 519527. RAWSON, P. F., DHONDT, A. V., HANCOCK, J. M., AND KENNEDY, W. J., eds., 1996, Proceedings of the Second International Symposium on Cretaceous Stage Boundaries, Brussels 1995, Bulletin van het Koninklijk Belgisch Instituut voor Natuurwetenschappen, Aardwetenschappen, v. 66, Supplement, 117 p.

AMMONITE ZONATIONS

Jake M. Hancock , Philip J. Hoedemaeker2 and Jacques Thierry3
(1) Imperial College, Science, Technology and Medicine, Department of Geology, Royal School of Mines, Prince Consort Road, London SW7 2BP, United Kingdom (2) National Museum of Natural History, Postbus 9517, 2300, ra Leiden, the Netherlands (3) Universite de Bourgogne, Centre des Sciences de la Terre and U. M. R. C. N. R. S. n 5561 Paleontologie analytique et Geologie sedimentaire, 6, Bd Gabriel, 21000, Dijon, France
GRADSTEIN, F. M., AGTERBERG, F. P., OGG, J. G., HARDENBOL, J., VAN VEEN, P., THIERRY, J., AND HUANG, Z., 1994, A Mesozoic time scale: Journal of Geophysical Research, v. 99, p. 2405124074. GRADSTEIN, F. M., AGTERBERG, F. P., OGG, J. G., HARDENBOL, J., VAN VEEN, P., THIERRY, J., AND HUANG, Z., 1995, A Triassic, Jurassic and Cretaceous time scale, in Berggren, W. A., Kent, D. V., Aubry, M.-P., and Hardenbol, J., eds., Geochronology, Time scales and Global Stratigraphic Correlation: Tulsa, SEPM Special Publication 54, p. 95126. OGG, J. G., 1995, Magnetic polarity time scale of the Phanerozoic, in Ahrens, T. J., ed., Global Earth Physics, A Handbook of Physical Constants: American Geophysical Union AGU Reference Shelf, v. 1, p. 240270. CRETACEOUS PERIOD
Ammonite biostratigraphy is a key element in the organization of Cretaceous stratigraphy. Ammonite zones and subzones are used to dene most stage and substage boundaries. The current Cretaceous ammonite zonation, which is continuously improved, reects an evolution towards a consensus scheme. The Colloque sur le Cretace in Lyon, France (1963, published in 1965), the Symposium on Cretaceous stage boundaries held in Copenhagen, Denmark (1983, published in 1984), the International Symposium on Cretaceous Stage Boundaries in Brussels, Belgium (1995, published in 1996), the meeting on Tethyan and boreal Cretaceous Maastricht, the Netherlands (I.G.C.P. Project n 362, 1995) and the 5th International Cretaceous Symposium in Freiberg, Germany, (1996), are important milestones in this process. The zonations used on the Cretaceous Charts originate from the most recently published synthesis (Hancock, 1991, Bulot et al., 1992 and Hoedemaeker et al., 1993) or from publications devoted to specic

CALPIONELLIDS

Jurgen Remane Universite de Neuchatel, Institut de Geologie, 11, rue Emile-Argand, CH 2007 Neuchatel, Switzerland
There are only minor paleobiogeographic variations in the composition of calpionellid faunas. Regional differences in the relative frequencies of species or genera do exist: The genera Calpionellopsis, Calpionellites and Calpionella elliptica are more frequent in the southern part of the Mediterranean basin than in southeastern France. On the other hand, only in the central part of their domain, corresponding
1. The occurrence of calpionellids in the basal Hauterivian was conrmed by Blanc (pers. comm. 1995) who discovered Tintinnopsella carpathica in a borehole in Neuchatel. Together with the nds of cal pionellids in the Hauterivian of the Slovak Carpathians this justies the establishment of a Tintinnopsella Zone. The problem with this zone is, however, that both its boundaries are dened by extinction events so that it does not posses truly diagnostic species. In certain regions calpionellids disappear already in the Valanginian, or at least there are intervals without calpionellids from the middle Valanginian upward. 2. A subdivision of the Calpionellites Zone is possible due to the appearance of new species of Calpionellites shortly after Ct. darderi, but more data are necessary to be sure of the exact position of these events due to the rarity of these forms. Taxonomy of the various species may also still need some clarication 3. At the International Symposium on Cretaceous Stage Boundaries in Brussels, Belgium 1995, the Valanginian working group decided to equate the base of the Valanginian Stage with the base of the Calpionellites Zone, a proposal to become ofcial with the denition of a boundary stratotype. The boundary formerly used by ammonite workers in France was at the base of the Otopeta Zone, corresponding to the base of the Praecalpionellites murgeanui Subzone or the middle of the Vocontian subzone D3. 4. The rst appearance of Tintinnopsella longa in the upper part of Zone C, conrms the observation in the Vocontian Basin but the precise level may still be subject to further renement. 5. There is a certain confusion as to the scope of a Calpionella elliptica Zone or Subzone. Its base should correspond to the rst appearance of C. elliptica, in the uppermost Zone B but some authors have also used it as a synonym of Zone C of Remane (1963). 6. Calpionellids have originated in the central Tethys. Only there the transition from Chitinoidella can be observed. Several successive waves of faunal migration originate from the central Tethys region. In the eastern Sierra Madre of Mexico, calpionellids appear only in the lower part of zone B; in central Mexico they appear in Zone C (Adatte et al., 1996. Another important migration occurs in Zone D, (perhaps two closely spaced events), documented in the state of Oaxaca (Mexico) and the northeastern Caucasus (Remane, in press). It is of course very tempting to relate these faunal migrations to marine highstands. In any event, on the carbonate platform of the Jura mountains, marine transgressions could be dated by calpionellids as middle to higher Zone D and as Zone E and a carbonate platform in the northeastern Caucasus was drowned at the beginning of Zone D.

RUDISTS

In western Europe, the lowermost transgressive Cenomanian is characterized by the rst appearance of Ichtyosarcolites triangularis, an eurytopic species represented both in carbonate and siliciclastic littoral facies (Philip 1978; Bilotte 1985). In the periadriatic area there is in general no hiatus between the Albian and the Cenomanian. The Cenomanian being characterized by the rst appearance of genera like Caprina, Neocaprina, Orthoptychus, etc. (Polsak 1965; Carbone et al., 1971; Sliskovic 1971; Sirna 1982). The upper Cenomanian coenozone contains cosmopolitan species (Caprinula boissyi, Sauvagesia sharpei) allowing correlations between western European and Periadriatic regions (Philip 1978; Iannone and Laviano 1980; Polsak et al., 1982).

Turonian

Due to complex paleogeographic events, a strong rudist renewal occurs at the Cenomanian-Turonian boundary (Philip and Airaud- Crumiere 1991). In sections without hiatuses (i.e. Provence, Philip 1978) ` the rst appearance of Hippuritids takes place in the lowermost Turonian. In western Europe, Hippuritids (Vaccinites, Hippurites) provide a zonation of the Turonian calibrated to ammonite zones ( Devalque et al., 1982; Platel 1982; Bilotte 1985), while in the periadriatic area the Turonian is poorly documented (Polsak 1962).

Coniacian and Santonian

In western Europe, three coenozones, well calibrated to ammonite zones, characterize this interval (Philip 1970; Pons 1977; Bilotte 1983, 1985; Floquet et al., 1982; Floquet 1990). In the periadriatic area only the Santonian displays rich and well differentiated rudist coenozone (Polsak 1965; Laviano and Sirna 1979).
Campanian and Maastrichtian
Jean Philip Centre de Sedimentologie et Paleontologie, Universite de Provence (Aix Marseille), Centre Saint Charles, Place Victor Hugo, 13331 Marseille cedex 03, France
During the late Cretaceous (Cenomanian to Maastrichtian) rudists extend widely on the shelf areas of southern Europe. According to the paleogeographical evolution of the western Tethyan area the rudist provinciality increases (Philip 1985). Two main rudistid provinces can be distinguished: the Periadriatic (Apulian) province and the western European province. Thus cosmopolitan species (recorded with asterisks on the chart) can be found in both provinces and constitute an accurate basis for correlations. Three rudist families contribute to the biozonation of the upper Cretaceous: Caprinidae (mainly for the Cenomanian), Hippuritidae (from the lower Turonian to the Maastrichtian), Radiolitidae for the entire upper Cretaceous).

Subdivisions of the Jurassic Subsystems
Stage boundaries and their subdivisions into zones, subzones and horizons, have been continuously rened over the last twenty years. Subdivisions in the Hettangian (Mouterde and Corna, 1991), Sinemurian (Corna et al., 1991) and Pliensbachian (Dommergues et al., 1991), are essentially based on the subdivision dened in northwestern Europe (sub-boreal realm: England, France, northern Spain, Portugal and Germany). Prominent differences in ammonite faunas appear only southward in the tethyan realm (Italy and southern Spain). Provincialism begins to be noticeable in the Toarcian (Elmi et al., 1991), Aalenian (Contini et al., 1991) and Bajocian (Contini et al., 1991), but the northwestern European areas (sub-boreal realm) remain the basic reference for the zonal scheme. Alternative units have been plotted alongside the standard divisions, as well as for zones or subzones in the two realms. The basic scheme for the Bathonian is based on Mediterranean areas (Mangold, 1991) where the ammonite faunas are more diverse and better known than in northwestern Europe. However, there is no complete agreement on a standard scheme of stage zonal subdivisions and on correlations between boreal and tethyan realms, therefore some of the alternative zones and subzones currently used are referred to on the chart. For the Callovian (Thierry et al., 1991) and lower Oxfordian (Cariou et al., 1991) when boreal inuences extend southward to Spain and Portugal, the standard reference is based again on the northwestern European sub-boreal realm. Correlation of biostratigraphic units are rather easy during the Callovian. Problems arise with middle-upper Oxfordian, Kimmeridgian (Cariou et al., 1991; Hantzpergue et al., 1991) and especially during the Tithonian (Geyssant and Enay, 1991) when increasing provincialism complicates correlations. Connections between southern Europe and northern Europe are episodic and endemic faunas settle in northern Aquitaine, the northern Paris Basin and Germany (Biome francogermanique, Hantzpergue et al., 1991). The late Jurassic regression inuences ammonite diversity and distribution. On the chart, it was impossible to represent all subtleties, therefore the boreal scheme for the Oxfordian through Tithonian Stages was selected as the standard.
CARIOU, E., AND HANTZPERGUE, P., 1997, Biostratigraphie du Jurassique ouestEuropeen et Mediterraneen: Bulletin Centre Recherche Exploration-Produc tion Elf-Aquitaine, Memoire 17, p. 1440.
The main subdivisions of the Jurassic follow the decisions of the Colloques du Jurassique in Luxembourg (1962, 1967) albeit with minor modications. The Lias/Dogger and Dogger/Malm boundaries can be correlated between the faunal realms with relative ease due to a homogenization of faunas. The Lias/Dogger boundary ( Toarcian/ Aalenian boundary) is placed between the last Toarcian ammonite zone (Aalensis/ Fluitans Zone ) recognizable in both the boreal and tethyan domains (Elmi et al., 1991), and the basal zone of the Dogger (Opalinum Zone, Opalinum Subzone) of the Aalenian Stage (Contini et al., 1991). Such a decision eliminates the traditional boundary established by Haug in the last century and discussed by generations of biostratigraphers but

Numerous Italian and German authors (Parona, 1890, 1892; Pantanelli, 1880; Rust, 1885, 1898) were among the pioneers in publishing papers dealing with Jurassic radiolarians. Since then successive workers published new information on the Jurassic fauna of Europe (Cayeux, 1891, 1896; Deandre, 1953; Dumitrica, 1970; Baumgartner, 1980 ; De Wever, 1982, 1986). However, in the last two decades the number of papers published increased dramatically and the rst biozonation for Europe was published by Baumgartner, De Wever and Kocher in 1980. Unfortunately, most papers dealt with the tethyan area and very little work was done on the boreal area. Information on Jurassic radiolarians is abundant for the folded tethyan terranes and radiolarians are rock forming (radiolarite) in numerous localities. The present set of tethyan marker species is based on recent publications by Gorican (1987, 1994) and on the synthesis published by the InterRad working group. There is essentially no literature describing well preserved boreal or sub-boreal faunas. Only occasional species are mentioned from scattered localities in Scotland, (Dyer and Copestake 1989) and Russia (Khabakov 1973; Bragin in press). Illustrations are, however, marginal and of limited use. Therefore, since no reliable datums exist for the boreal province none were entered on the Jurassic chart. In western Europe faunal differences between warm and cold depositional environments has not yet been demonstrated with certainty. This is mainly do to the fact that most information comes from radiolarite-type rocks which were deposited under the most active parts of upwelling (De Wever et al., 1994). In settings of upwelling mixtures of species representing warm, cold, shallow and deep water faunas often co-occur. Before a distinction between provinces can be attempted, it will be necessary to identify from the appropriate data which markers are indicators of boreal or tropical environments. Most of the Jurassic datums are calibrated with other biozonations such as ammonites, calcareous nannofossils or foraminifers. First order calibration is to biozones of other fossil groups or in absence of such data directly to the stage. There is no rst order calibration with the numerical scale in Ma.

other regions were treated by Bown (1992; British Columbia, Canada and Timor) and Bralower et al. (1991; ODP Leg 122 NW Australia). Direct correlation of calcareous nannofossil ndings with ammonite zonations are very rare. The positions of most events on the chart are thus chosen more as educated guesses than after any criterion.

Carnian

In the lower Carnian (Cordevolian; aon ammonite zone), the assemblage is dominated by calcispheres, namely Orthopithonella misurinae and O. prasina. Also found are Carnicalyxia tabellata and Cassianospica curvata (Janofske, 1992).

Norian

The Norian of the Queen Charlotte Islands, B.C., Canada furnished: Prinsiospheara triassica, Thoracosphaera sp. indet., Orthopithonella geometrica and the rst two real coccoliths Crucirhabdus minutus and, questionably, C. primulus (Bown, 1992). Bralower et al. (1991, 1992) reported O. geometrica, T. wombatensis, P. triassica and C. primulus to appear together on the Wombat Plateau off northwestern Australia followed by Thoracosphaera sp.

Rhaetian

GALLET, Y., BESSE, J., KRYSTYN, L., AND MARCOUX, J., 1996, Norian magnetostratigraphy from the Scheiblkogel section, Austria; constraint on the origin of the Antalya nappes, Turkey: Earth and Planetary Science Letters, v. 140, p. 113122. GRAZIANO, S., AND OGG, J. G., 1994, Lower Triassic magnetostratigraphy in the Dolomites region (Italy) and correlation to Arctic ammonite zones: Eos, Transactions American Geophysical Union, v. 75, (1994 Fall Meeting Supplement), p. 203. KENT, D. V., OLSEN, P. E., AND WITTE, W. K., 1995, Late Triassic-Early Jurassic geomagnetic polarity sequence and paleolatitudes from drill cores in the Newark rift basin, eastern North America: Journal of Geophysical Research, v. 100, p. 1496514998. MUTTONI, G., KENT, D. V., AND GAETANI, M., 1995, Magnetostratigraphy of a Lower-Middle Triassic boundary section from Chios (Greece): Physics of the Earth and Planetary Interiors, v. 92, p. 245260. MUTTONI, G., KENT, D. V., BRACK, P., NICORA, A., AND BALINI, M., 1997, Middle Triassic magnetostratigraphy and biostratigraphy from the Dolomites and Greece: Earth and Planetary Science Letters, v. 146, p. 107120.

Records of dinoagellates are relatively rare in the Triassic and are essentially restricted to its upper part. The oldest unequivocal representative of this group was described by Stover and Helby (1987) from the middle Triassic of Australia. Although palynomorphs of marine origin are abundant in the lower and middle Triassic of the Arctic as well as in the Muschelkalk of the Alpine/Germanic realm, no dinoagellate cysts were identied.

Southern hemisphere

The most complete succession of dinoagellates is known from Australia where Helby et al. (1987) subdivided the upper Triassic into ve zones. Most of the FADs and LADs on the chart are based on this publication. However, the calibration of these assemblages is relatively poor because of the absence of independent control. The assemblages described by Brenner et al. (1992) from the Wombat Plateau, offshore northwestern Australia which are calibrated with ostracodes and magnetostratigraphy conrm the stratigraphic interpretation given by Helby et al. (1987).

Arctic

Records of radiolarians are still relatively rare from Triassic sedimentary rocks and most of the information available is concerning Alpine faunas. Triassic radiolarian are known since a long time but comprehensive studies are rather recent. A preliminary note by Rust (1887) was followed by a more comprehensive study, Rust (1892) which recorded 29 species from 28 Triassic samples of central European hornsteins and calcareous limestones. Parona (1892) gured a dozen poorly preserved forms. More recent studies on the same levels are from De Wever et al. (1979); De Wever (1982); Kozur and Mostler (1972, 1978, 1979); Dumitrica (1978a,b); Gorican and Buser, (1990) and Lahm, 1984). Samples yielding radiolarians are rare from scattered localities in Europe, mainly concentrated in the tethyan area (Austria, Italy, Slovenia, Serbia, Montenegro, Albania, Greece and Turkey). Most of the Triassic FADs and LADs were calibrated with conodonts, ammonites or pelecypods. Few well preserved boreal and sub-boreal faunas have been described to date and therefore no FADs or LADs of boreal markers are entered on the chart. Only recently some faunas were recorded from Russia ( northern Siberia, Egorov, 1995).

In the Arctic, Norian and Rhaetian sections are characterized by regular occurrences of dinoagellates. Assemblages calibrated with ammonites are known from the middle Norian (N. columbianus zone) of the Canadian Arctic Islands (Bujak and Fisher, 1976). Based on sporepollen evidence, lower Norian and upper Carnian ages are suggested for the oldest occurrences of the Sverdruppiella/Noricysta assemblages.

Alpine/Germanic

In the Alpine/Germanic realm, distribution of dinoagellates is restricted to the uppermost Triassic. Diverse assemblages were described from the Rheatian in the Alpine Kendelbach Graben section in Austria (Morbey, 1975). Most of the assemblages from the Rheatian Germanic facies are not diverse. No dinoagellates older than Rheatian are known from the Alpine/Germanic realm.
DE WEVER, P., 1982, Radiolaires du Trias et du Lias de la Tethys. Systematique, Stratigraphie: Societe geologique du Nord, Lille, Publication 7, 599 p.
BRENNER, W., BOWN, P. R., BRALOWER, T. J., CARSQUIN-SOLEAU, S., ` DEPECHE, F., DUMONT, T., MARTINI, R., SIESSER, W. G., AND ZANINETTI, L., 1992, Correlation of Carnian to Rhaetian palynological, foraminiferal, calcareous nannoplankton, and ostracode biostratigraphy, Wombat Plateau, in von Rad, U., Haq, B., Proceedings of the Ocean drilling Program, Scientic results, v. 122, p. 487495 BUJAK, J. P., AND FISHER, M. J., 1976, Dinoagellate cysts from the Upper Triassic of Arctic Canada: Micropaleontology, v. 22, p. 4470. HELBY, R., MORGAN, R., AND PARTRIDGE , A. D., 1987, A palynological zonation of the Australian Mesozoic, in Jell, P. A., ed., Studies in Australian Mesozoic palynology: Memoir Association Australaisian Paleontologists, v. 4, p. 194. MORBEY, S. J., 1975, The Palynostratigraphy of the Rhaetian Stage, Upper Triassic in the Kendelbachgraben, Austria: Palaeontographica, Abteilung B, v. 152, p. 183.
STOVER, L. E., AND HELBY, R., 1987, Some Australian Mesozoic mikroplankton index species, in Jell, P. A., ed., Studies in Australian Mesozoic palynology: Memoir Association Australaisian Paleontologists, v. 4, p. 101134.

SPORE-POLLEN

stratigraphic intervals. The palynological records from the upper part of the Carnian and the Norian are incomplete as a result of poor preservation of palynomorphs.

G. ubiquita O. amalthei K. multicostata

195.19

195.19 195.85

P. butterlini

PALEOMAYNCINA TERMIERI*
Cuersithyris davidsoni & Cuersithyris radslockiensis

L. variabile D. priscum

196.83

Nannobelus oppeli

O. hamiltoniae

197.45

P. harpa

Marginulina spinata

OXYNOTUM OBTUSUM

198.77

P. robustus

198.19

197.92 198.19

197.61

L. variabile (common) O. praecursor* L. compressa* P. termieri* D. priscum (rare)

C. crassus

198.58
O. hamiltoniae 198.58 C. crassus

L. variabile

I. sulcata I. muelensis L. inaequistriata mg P.
L. quadricostata mg M. L. radiata mg M.

200.14 199.36

Spiriferina betacalcis, Piarorhynchia juvenis, & Zeilleria (Cincta) cor
TURNERI (BIRCHI) SEMICOSTATUM BUCKLANDI

Nannobelus acutus

199.67

O. danica

199.55 199.55

199.55

200.43

P. marthae

M. elegans
C. crassireticulata D. priscum 200.72 B. langii (common)

200.72

E. moorei O. aspinata
Cuneirhynchia oxynoti & Zeilleria (Z.) vicinalis

N. issleri D. fasciata

201.11

201.31

C. circumscripta C. betzi

201.89 201.89

P. liasicus T. patulus

INVOLUTINA LIASSICA

C. circumscripta K. praeluxuriosa K. praeluxuriosa
Vaginulina subporrecta Ichtyolaria xyphoidea 202.83
Lenticulina quadricosta mg M. L. curva mg M. Marginulina noervangi

L. quadricosta mg M.

V. diacrorhaetium LIASICUS

204.25 204.72 205.19

Schwegleria

C. circumscripta

*Tethyan ranges provisional

S. punctulata

204.25 204.25
I. liassica C. buisensis C. circumscripta O. aspinata

204.01

Zeilleria (Zeilleria) perforata
Lingulina striata Lingulina collenoti Lenticulina austroalpina mg L.
1. Ages for the stage boundaries are directly inferred from radiometric data and are shown to the nearest 0.1 m.y. with statistical uncertainty in parentheses (Gradstien, et al., 1995). All other ages shown to the nearest 0.01 m.y. are intended only as a place holder to help determine the relative position of events in different columns. Roundoff error in plotting required two decimal point precision for each entry to avoid apparent misalignments. 2. First Appearance Datums (FADs; originations; ) and Last Appearance Datums (LADs; extinctions; ) closely spaced in time may have bent flags. In this case, the time position of the event is the flag stem at the edge of the column.

243.04

241.66 241.86

ROMUNDERI

TARDUS HEDENSTROEMI
KOROSTELEVI TURGIDUS SVERDRUPI DECIPIENS MORPHAEUS

243.64

SPINIGER & PLURIFORMIS & PRAHLADA 244.03

L. brevicula L. obsoleta

Densoisporites spp. (common) A. robustus P. reticulatus V. jenensis
MEANDROSPIRA PUSILLA M. pusilla

243.24 244.03

POROCHARA TRIASSICA

N. triangularis

243.95

( 4.8)

KOLYMENSIS HEDENSTROEMI

244.62

GRACILITATIS

245.19

K. saeptatus L. variabilis P. disertus N. striata (common) P. fungosus

SVERDRUPI

245.95

245.20

245.38 245.95 246.25 246.89

245.57 246.32

ROSENKRANTZI

ROHILLA

INDUAN

248.20

246.32 246.70
CANDIDUS STRIGATUS COMMUNE

246.32

FREQUENS

245=In2

Lundbladispora spp. (common) Lundbladispora Pechorosporites spp. (common) spp. (common) 246.32
POROCHARA / VLADIMIRIELLA GLOBOSA ?

N. kummeli

COMMUNE

246.89 247.07

247.07
CONNECTENS & TIBETICUM

247.82

BOREALE

247.45

PASCOEI BOREALE

S. richteri P. pococki

247.82 248.15 247.45 U. imperialis 247.45 C. chalasta* P. pococki C. chalasta* (common) 248.15
RECTOCORNUSPIRA 247.07 KAHLORI

R. kahlori R. kahlori

I. isarcica

248.2 ( 4.8)

WOODWARDI

H. typicalis

Schematic Condensed Section Top Lowstand (where indicated) Minor Medium Major Sequence Boundaries
Sequence nomenclature Sequence boundary nomenclature for the new sequences is based on the stage in which a sequence boundary occurs and its ordinal position counting up from the stage base. For example, the sequence boundaries in the Anisian are An1 thru An4 with An1 the oldest. Note that it is the position of the sequence boundary that determines the name, even if most of the sequence is in the next younger stage. In the new sequences lowstands are not distinguished. The systems tract boundary between lowstand and transgressive systems tracts is not of chronostratigraphic significance and thus is not shown on this chart.
1. Ages for the stage boundaries are directly inferred from radiometric data and are shown to the nearest 0.1 m.y. with statistical uncertainty in parentheses (Gradstein, et al., 1995). All other ages shown to the nearest 0.01 m.y. are intended only as a place holder to help determine the relative position of events in different columns. Roundoff error in plotting required two decimal point precision for each entry to avoid apparent misalignments. 2. First Appearance Datums (FADs; originations; ) and Last Appearance Datums (LADs; extinctions; ) closely spaced in time may have bent flags. In this case, the time position of the event is the flag stem at the edge of the column. 3. The standard format for names other than ammonites is: Zones--full generic and specific name Appearance Datums--Abbreviated generic name and full specific name except for sp(p). for which full generic names are given. 4. Uncertain stratigraphic positions for zonal boundaries, FADs, and LADs are shown with dashed lines.