Article

Probleme der Triasgliederung und Parallelisierung der germanischen und tethyalen Trias. Teil II: Anschluss der germanischen Trias an die internationale Triasgliederung

Authors:
To read the full-text of this research, you can request a copy directly from the author.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the author.

... Studies on Triassic charophytes, however, are rather few and fossils have only been described from southern Sweden (Horn af Rantzien, 1953aRantzien, , 1954, Russia (Saidakovsky, 1966;Saidakovsky and Kisielevsky, 1985), Ukraine (Saidakovsky, 1960), Kazakhstan (Kisielevsky, 1991), U.S.A. (Peck and Eyer, 1963;Kietzke, 1987), Argentina (Benavente et al., 2012), Germany (Kozur, 1975;Breuer, 1988), Poland (Bilan, 1988(Bilan, , 1991Zatoń et al., 2005), Slovenia (Martín-Closas et al., 2009) and China (Wang and Huang, 1978;Huang, 1983;Lu and Luo, 1984). Nearly all occurrences of Triassic charophytes are recorded from Laurasia (Benavente et al., 2012). ...
... Gyrogonite-rich fossil sites or intervals are abundant in the Triassic deposits from the Germanic Basin. These successions have been the subject of charophyte-based biostratigraphic studies (Bilan, 1988;Kozur, 1974aKozur, , 1974bKozur, , 1975. Triassic charophyte assemblages have been found principally in freshwater-to-brackish carbonate-rich or limestone deposits from the Upper Buntsandstein (Anisian) and Keuper facies (late Ladinian-Norian) in central Europe (Bilan, 1969(Bilan, , 1974(Bilan, , 1988(Bilan, , 1991Breuer, 1988;Kozur, 1975) and Russia (Saidakovsky, 1966;Saidakovsky and Kisielevsky, 1985). ...
... These successions have been the subject of charophyte-based biostratigraphic studies (Bilan, 1988;Kozur, 1974aKozur, , 1974bKozur, , 1975. Triassic charophyte assemblages have been found principally in freshwater-to-brackish carbonate-rich or limestone deposits from the Upper Buntsandstein (Anisian) and Keuper facies (late Ladinian-Norian) in central Europe (Bilan, 1969(Bilan, , 1974(Bilan, , 1988(Bilan, , 1991Breuer, 1988;Kozur, 1975) and Russia (Saidakovsky, 1966;Saidakovsky and Kisielevsky, 1985). These European assemblages have been particularly studied owing to their biostratigraphic interest. ...
Article
The record of fossil charophytes from Sweden was previously restricted to the Ladinian-earliest Carnian Falsterbo Formation. Here, we present a charophyte assemblage from the Upper Triassic Kågeröd Formation exposed at the Bälteberga Gorge (Skåne, southern Sweden) from the perspectives of taxonomy, taphonomy, palaeoecology and biostratigraphy. The microfossils originate from an interval of reddish sandy mudstone and are represented by rare fossil thalli, calcium carbonate encrustations of thalli and numerous calcified fructifications, called gyrogonites. The assemblage is relatively diverse, comprising six species belonging to four genera of the family Porocharaceae (Auerbachichara cf. rhaetica, Porochara sp., Stellatochara germanica, Stellatochara aff. subsphaerica, Stenochara aff. donetziana, Stenochara aff. kisielevskyi). Both the sedimentological context and the preservation of the charophyte remains point to an autochthonous origin for the charophyte-bearing strata. An autochthonous origin together with the habitat of modern charophytes, infer that the charophyte interval was deposited in shallow ephemeral pond or lake in a terrestrial setting. Their occurrence is also indicative of low amount of nutrients and the numerous thalli encrustations suggest a rather alkaline water composition. Some of the described species (Auerbachichara cf. rhaetica and Stellatochara aff. subsphaerica) are useful for biostratigraphical correlations which attributes the assemblage to the Auerbachichara rhaetica Range zone (sensu Bilan, 1991) in the proposed Germanic Triassic charophyte zonation. This range zone is assigned to a latest Carnian to late Norian age, strengthened by an interlayering with rocks containing a characteristic assemblage of palynomorphs (Corollina meyeriana subzone a and b) in the Upper Triassic of the Polish part of the Germanic Basin. The findings of the first Triassic thalli further strengthen the suggestion that the early Mesozoic fossil record of charophytes is not solely composed of oospores and gyrogonites. A better understanding of vegetative fossil remains (silicified thalli and encrustations) of charophytes may provide important future palaeoecological implications and links between recent and extinct forms. Our findings also provide evidence that charophyte occurrences in the Kågeröd Formation are strictly controlled by palaeoenvironmental factors.
... In the North German Basin the first Triassic fossils appear in the su 2 of the 'Unteren Buntsandstein', that is in the sequence overlying the basal 'Brockelshiefer' (Kozur 1975). According to Kozur (lac. ...
... 8). They are however still undetermined, but may prove to be useful for a correlation of the Danish deposits with the German ones, where a preliminary Chara zonation has been carried out by Kozur (1975). Kozur correlates the German Middle Buntsandstein with the J akutianearly Olenikian stages of the Scythian Series. ...
... A generally low salinity of the sea is indicated by impoverished ostracod faunas of Darwinula and ? Clinocypris combined with occurrence of Chara gyrogonites (Kozur 1975, Hiltermann & Madler 1979. ...
Article
The Triassic deposits of the Danish territory are mapped, described and characterized by means of wire line log motifs. Three facies provinces are recognized: A southern and central Germano-type Facies Province, a Northern Marginal Facies Province fringing the basin center, and a Central Graben Facies Province with affinities to the Southern North Sea Basin. The traditional German lithostratigraphic nomenclature previously used in the Germano-type Facies Province is proposed replaced by a system composed of four groups each of two formations corresponding to four Triassic megaphases of sedimentation: Bacton Group including Bunter Shale Formation and Bunter Sandstone Formation, Lolland Group (new) including Ørslev Formation (new) and Falster Formation (new), Jylland Group (new) including Tønder Formation (new) and Oddesund Formation (new), and Mars Group (new) including Vinding Formation and Gassum Formation. In the other facies provinces the nomenclature previously proposed for the Central and Southern North Sea is adopted. A summary of the basin evolution is given for each formation description.
... In contrast, climatic conditions were different during deposition of the middle Carnian (middle to upper Julian) Stuttgart Formation (Schilfsandstein). Kozur (1972Kozur ( , 1975 inferred for this time interval a wet climate that seemed not to fit well with the palaeogeographic position of the Germanic Basin at that time. Interestingly, during this same time interval, in the northwestern Tethyan Lunz and North Alpine Raibl formations brachyhaline marine to brackish intercalations occur with conchostracans and brackish ostracods, also indicating a strong fresh water influx. ...
... The correlation of the Stuttgart Formation (Schilfsandstein) with the Tethyan scale is rather well established (Figs. 2, 3). Kozur (1972Kozur ( , 1975 correlated the Schilfsandstein by ostracods, megaflora and megaspores with the Julian of the Lunz Beds and the North Alpine Raibl Beds of Austria and contemporaneous beds in Hungary. The wet climatic interval of the Schilfsandstein between under-and overlying dry climates was also taken into consideration, because brackish intercalations also are known from the Lunz Beds, indicating a strong influx of fresh water into the Tethys within this stratigraphic interval. ...
... Warth (1988) restudied this fauna and sharply reduced its diversity to only 3 species within 3 genera, and he concluded that this fauna and all other subaquatic Schilfsandstein faunas had lived either in continental lakes with variable salt content or in fluvial environments. Kozur (1975) and Bachmann and Kozur (2004) have since painted a more detailed picture without such generalisations. Geyer (1989Geyer ( , 1990) also pointed out that the question of marine influence in the Schilfsandstein (Stuttgart Formation) can be considered only within narrow stratigraphic horizons and not in terms of any sort of basin-wide generalisation. ...
Article
The Middle Carnian Wet Intermezzo (MCWI) of the Stuttgart Formation (Schilfsandstein) and age-equivalent strata of the northwestern Tethys occurred entirely within equivalents of the upper subzone of the Austrotrachyceras austriacum ammonoid zone of the late Julian. Its duration is estimated to be only about 0.7–0.8 myr. In both the Germanic Basin and the northwestern Tethys, the warm climate during the MCWI was characterized by a rate of precipitation that exceeded somewhat the evaporation but was not so great as to be pluvial. The MCWI was related to the atmospheric circulation of a megamonsoonal system that was characterized by strong, moisture-laden, northwesterly flowing trade winds that rose as they reached the estimated 2000–3000 m high eastern shoulder uplift of a huge rift causing them to drop an extraordinary amount of rain. This eastern shoulder uplift lay within the Caledonides of modern day western Scandinavia. This region only, between 30 and 50°N palaeolatitude, had a truly pluvial climate, and the huge amounts of fresh water dropped there transported large amounts of siliciclastics from this rift-shoulder uplift southward into the Germanic Basin.
... Kozur and Reinhardt (1969) reported charophytes from the Muschelkalk and lower Keuper assigned to Porochara, Stellatochara and Stenochara. Kozur (1975Kozur ( , 1974 proposed a succession of charophyte zones for much of the Triassic Section in the Germanic Basin (Fig. 6). Breuer (1988) reported Clavatorites (as Cuneatochara) from the Lower Keuper of southwestern Germany. ...
... Bilan's zonation appears to have been driven by a desire to create zones that are essentially the same as those proposed by Saidakovsky and Kiselevsky for the Triassic of the Russian platform, even though the Polish Triassic charophytes do not reprise those zones. Furthermore, correlation of the Polish Section to the classic Germanic Triassic strata was already clear before the work of Bilan, so the charophyte zonation of the German strata (e.g., Kozur, 1975Kozur, , 1974 also heavily influenced Bilan's work. A critical review of Bilan's zonation identifies only three useful biostratigraphic constructs: ...
Article
Permian charophytes are known from the Ukraine, Russia, Kazakhstan, Germany, Saudi Arabia, China, the USA, Brazil, Paraguay and India. Most of these records are of Middle- Late Permian Age and are the basis of local biostratigraphic zonation in southern Russia and China. Development of a robust Permian charophyte biostratigraphy will require a more extensive record. Triassic charophytes are known from Germany, Sweden, Poland, Slovenia, Bulgaria, the Ukraine, Russia, Morocco, Congo, the USA, Argentina, Kazakhstan and China. This encompasses records from all Triassic stages and has been the basis of detailed biostratigraphic zonation in southern Russia-Kazakhstan-eastern Europe. Permian and Triassic charophyte biostratigraphy at the level of genus does not provide detailed correlations beyond local or regional schemes. Nevertheless, it does identify some important evolutionary datums that constrain the timing of important biotic events in the Permian-Triassic evolutionary history of the Charophyta, including: (1) Early Permian extinction of the Palaeocharaceae; (2) Late Permian extinction of the “Trochiliscales” (Moellerinales); (3) Carboniferous origin of the paraphyletic Porocharaceae, soon followed during the Permian by the origin of the multicellular basal plate; and (4) an important generic turnover of charophytes across the Triassic-Jurassic boundary, though there are insufficient data to identify this as a mass extinction.
... He shows the whole of this zone to be correlative with late Middle Carnian rocks of the Alpine section and the lowermost Chink and lower Dockum Group of the southwestern United States. Interestingly, the Schilfsandstein of the Germanic basin contains vertebrates very similar to those of the lower Dockum (Schmidt, 1928;Gregory, 1969) and is Middle Carnian (Kozur, 1975;Gall, Durand, and Muller, 1977), thus substantiating the palynomorph data on the lower Dockum and strengthening Newark correlation. Schaeffer and Mangus (1973) have shown that the lower Newark and the Chinle Formation and Dockum Group have very similar fish assemblages. ...
... The abbreviations (km 4, ko, ku, et cetera) are the standard European notation for Triassic stratigraphic units. The correlation between the German stratigraphic units and the European standard stages is largely from Kozur (1975). The column to the right of the Newark Fish zones shows the major faunal zones of the Newark: (A) Middle Triassic fauna from the Lower Economy beds; (B) zone typified by the presence of Chirotherinm-type footprints corresponding to Olsen and Galton's (1977) zone 1; (C) zone typified by the earliest appearance of Balrachopus-type footprintscorresponds to Olsen and Galtan's (1977) zone 2; (D) zone typified by the earliest appearance of Anomoepus-type footprints; it contains all the Jurassic fish zones described in this paper and is associated with extrusive volcanics in the Newarkthis and the following zone correspond to Olsen and Galton's (1977) zone 3; (E) zone without redfieldiids and well-defined semionotid zonesthis zone is entirely post-extrusive. ...
Article
Full-text available
New data on the distribution of fossil fish together with floral and tetrapod evidence are used to develop an internal correlation of the strata of the early Mesozoic Newark Supergroup of eastern North America. Within the Newark, we recognize five informal biostratigraphic zones, each characterized by a particular fish fauna. These fish zones are then related to other Mesozoic freshwater deposits, augmented by paly- nologic and tetrapod data, to the European type area, and to important Early Mesozoic terrestrial sequences elsewhere. The oldest fish zones are the Dictyopyge zone found in the Middle Carnian age rocks of the Richmond, Taylorsville, and Scottsburg Basins and the Middle and Late Carnian Diplurns newarki zone represented in the -ham group, Dan River Group, Gettysburg Basin, and Newark Basin. These two zones correlate with the Chinle Formation and the Dockum Group of the southwestern United States as well as the Middle and Late Carnian rocks of the German basin. *The three youngest zones, early Jurassic in age, are characterized primarily by species groups of the holostean Semionotus. Fishes of the "Semionotus tenuiceps group" zone are known from the Hettangian Feltville and Towaco Formations of the Newark Basin and the Turners Falls Sandstone of the Deerfield Basin. The "Semionotus micropterus group" zone is found in the Late Hettangian-Early Sinemurian rocks of the Shuttle Meadow and East Berlin Formations of the Hartford Basin and the "Midland fish bed" of the Culpeper Basin. Youngest of these semionotid zones is the Sinemurian "Semionotus elegans group" rep- resentatives of which occur in the Sinemurian Portland Formation of the Hartford Basin and the Boonton Formation of the Newark Basin. Correlation by these fish zones suggests that all the coal-bearing Newark rocks are divisible into an older and younger sequence both dated palynologically (by others) as Middle Carnian. Further, while the time span over which extrusive basalts were deposited is limited to the Hettangian and Sinemurian of the Early Jurassic, the individual basalt flow formations are not correlative among basins in a simple one to one manner according to the biostratigraphic data. With respect to the rest of the world, the "Semionotus tenuiceps group," "S. micropterus group," and the "S. elegans group" zones correlate with the European Early Jurassic, the Glen Canyon Group of the southwestern United States, the upper -- . Stormberg Group of southern Africa, and the Lower Lufeng of China.
... This mid-Carnian episode was initially recognized within the Germanic Basin by an influx of fluvial to brackish-water sands into the arid facies of the Keuper and within the Alpine region by the termination of the prograding reefs of the earlier Carnian accompanied by a negative carbon-isotope excursion. These fluvial sands of the "Wet Intermezzo" in the Germanic Basin are correlated by conchostracan and megaspore assemblages to marine deposits of the upper part of the Austrotrachyceras austriacum ammonoid zone of the uppermost Julian substage (e.g., Kozur, 1975;Kozur and Bachmann, 2010) (Appendix Fig. A.2). [Note: The Julian substage is used here as the lower of a two-substage division of the Carnian stage following Krystyn (1974) and its common usage in many Triassic stratigraphy papers (e.g., majority of the reviews in Lucas (2010)), even though a distinct Cordevolian substage is recommended by Kozur (2003) and Kozur and Bachmann (2010) for the lowermost transitional interval spanning the Daxatina canadiensis and Trachyceras aon ammonoid zones that is characterized by co-occurrences of Ladinian and Carnian taxa.] The end to this "wet intermezzo" interval in the Germanic-Alpine region coincides with the substage boundary between Lower (Julian) and Upper (Tuvalian) substages of the Carnian. ...
Article
Full-text available
Thick successions from the margins of the Triassic Yangtze Platform of the South China Block record a transition from carbonate-rich facies (Zhuganpo Formation and equivalents) to clastic-rich facies (Xiaowa Formation and equivalents) during the Carnian (early Late Triassic) that mark the final phase of termination of this long-lived platform. Cyclostratigraphy derived from spectral gamma-ray (SGR) intensity curves was combined with magnetostratigraphy of two sections in Guizhou Province (Wayao transect and its upward extension into the Geopark Wayao in Guanling county and the Laishike section in Zhenfeng county) and one location in Sichuan Province (Hanwang section). The cyclostratigraphy from all the Guizhou sections indicate a persistent suite of ca. 34 m, 9 m and 1.8 m cycles, which are consistent with the ratios of orbital-climate oscillations caused by long-eccentricity (405 kyr), short-eccentricity (~ 100 kyr) and precession (20 kyr). The magnetostratigraphy of all sections are consistent with the cyclicity and characteristic SGR features, thereby enabling a cycle-tuned magnetic polarity scale spanning ~ 2.4 myr. The main feature is a 1.3-myr interval of reversed polarity containing brief normal-polarity subchrons, and this reversed-polarity chron appears to correspond to the significant reversed-polarity-dominated interval spanning the upper half of the Trachyceras aonoides through lower half of the Austrotrachyceras austriacum ammonoid zones of the upper Julian (the lower substage of Carnian). This magnetostratigraphic correlation implies that the termination of the Yangtze Platform is coeval with the beginning of the mid-Carnian episode of climatic disruption in Europe, which is locally called the “Carnian Pluvial Event” or “Wet Intermezzo”, and with the temporary cessation of the platform carbonates in the Dolomites. The cycle-scaled magnetic-polarity time scale supports the “Short-Tuvalian/Long-Norian” age model of the Late Triassic in which the base of the cycle-tuned polarity pattern from the Newark Group of eastern North America is younger than the end of the Julian substage.
... 5-1: Gliederungsmöglichkeiten des Buntsandstein mit Pflanzen, Conchostraken, Mollusken sowie Tetrapoden und deren Reichweiten. Gliederung in Anlehnung an Kozur (1975) und Reitz (1988). Ziffern 3 -8 im Unteren Buntsandstein: kleinzyklische Gliederung (Röhling 1993 Als Muschelkalk-Untergrenze wurden in Deutschland und in Polen Horizonte unterschiedlichen Alters festgelegt. ...
... The duration ofthe correspond- ing stages-Induan (6 Ma) and Olenekian (4 Ma) -is derived here from the Buntsandstein (see Sect. 5.9). The base of the Olenekian corresponds approximately with the base of the Hardegsen Formation ( Kozur 1975, Table 1, p. 590). How- ever, the above-mentioned correlation remains to be confirmed. ...
Chapter
The time span between 300 and 208 Ma has been analyzed using a combination of biostratigraphic, lithostratigraphic, magnetostratigraphic, and isotope-geochronometric temporal information. This methodology is termed herein “integrated time analysis” (geochronological analysis). The ages on the Time Scale (Fig. 1) are estimations of the duration of well-known lithostratigraphic and biostratigraphic units from the Tethyan region, the East European Platform (EEP), and Central Europe (CE).
... Although the 'Grès à Voltzia' belongs to the Buntsandstein, which is traditionally considered to be Lower Triassic, it is Early Anisian in age, i.e. ca. 8 Myr after the Permian-Triassic boundary [40], according to the biostratigraphic correlations between the Germanic Buntsandstein and the Alpine Triassic units [35,36]. Evidences of a Lower Anisian age of the 'Grès à Voltzia' are given by the conchostracans and the foraminiferal assemblages, but also by the occurrence of the bivalve Myophoria vulgaris, a typical Early Anisian species, and the lack of a closely related taxon, Costatoria costata, which is common in the Alpine Lower Triassic. ...
Article
The biotic recovery that succeeded the end-Permian life crisis event lasted a long period, estimated at ca 8 to 10 Myr, even 14 Myr. It is thought that it essentially proceeded from refugia whose geographic location can never be established. Their existence can nevertheless be inferred from the surprising stability exhibited by some fossil communities between the Late Palaeozoic and the Triassic. It is the case of the biocoenoses from the ‘Grès à Voltzia’ Formation (Upper Buntsandstein) of eastern France, which consist of Palaeozoic survivors (crustaceans, amphibians, insects, plants), taxa that announce the modern faunas (crustaceans, spiders, scorpions, insects), living fossils (lingulids, the panchronic species Triops cancriformis) as well as pioneering species which invaded rapidly the disturbed ecospaces (the herbaceous conifer Aethophyllum). The ‘Grès à Voltzia’ is Early Anisian in age and was deposited in a deltaic area, an environment transitional from nearshore to terrestrial, where locally less arid climatic conditions favoured the survival of plants and animals. The ‘Grès à Voltzia’ represents a model of the type of environment that may have acted as a refugium for terrestrial communities during the end-Permian mass extinction and its Triassic aftermath. To cite this article: J.-C. Gall, L. Grauvogel-Stamm, C. R. Palevol 4 (2005).
... This explains the continuity of usage of the Middle and Upper Triassic stage names since the work of Mojsisovics et al. (1895) and Bittner (1902). However, although Induan and Olenekian of Kiparisova & Popov (1956) are relatively old names for Lower Triassic stages, the Brahmanian of Waagen and Diener (in Mojsisovics et al. 1895) is a much older name and could have been used instead of Induan, as Kozur (1973Kozur ( , 1975) suggested (Fig. 10). The fact that the name with priority, Brahmanian, has been little used, using often-employed Induan is a step towards stability in the chronostratigraphic nomenclature. ...
Article
The Triassic chronostratigraphic scale is a hierarchy of three series, seven stages and 15 substages developed during nearly two centuries of research. The first geological studies of Triassic rocks began in Germany in the late 1700s and culminated in 1834 when Friedrich August von Alberti coined the term 'Trias' for the Bunten Sandsteins, Muschelkalk and Keuper, a thick succession of strata between the Zechstein and the Lias. Recognition of the Trias outside of Germany soon followed, and by the 1860s Austrian geologist Edmund von Mojsisovics began constructing a detailed Triassic chronostratigraphy based on ammonoid biostratigraphy. In 1895, Mojsisovics and his principal collaborators, Wilhelm Waagen and Carl Diener, published a Triassic timescale that contains most of the stage and substage names still used today. In 1934, Leonard Spath proposed a Triassic ammonoid-based biochronological timescale that differed little from that of Mojsisovics and his collaborators. In the 1960s, E. Timothy Tozer proposed a Triassic ammonoid-based timescale based on North American standards, and his timescale included proposal of four Lower Triassic stages (Griesbachian, Dienerian, Smithian and Spathian). The work of the Subcommission on Triassic Stratigraphy began in the 1970s and resulted in current recognition of seven Triassic stages in three series: Lower Triassic-Induan, Olenekian; Middle Triassic-Anisian, Ladinian; Upper Triassic-Carnian, Norian and Rhaetian. The 1990s saw the rise of Triassic conodont biostratigraphy so that four intervals that have agreed on Triassic GSSPs use conodont occurrences as defining features: bases of Induan, Olenekian, Anisian and Rhaetian. The bases of the Ladinian and Carnian are defined by ammonoid events. The base of the Norian remains undefined, but will most likely be defined by conodonts. Except for the Rhaetian, the Middle and Upper Triassic stages and substages have been fairly stable for decades, but there has been much less agreement on Lower Triassic chronostratigraphic subdivisions. Issues in the development of a Triassic chronostratigraphic scale include those of: stability and priority of nomenclature and concepts; disagreement over and changing taxonomy; the use of ammonoid v. conodont biostratigraphy; differences in the perceived significance of biotic events for chronostratigraphic classification; disagreements about the utility of relatively short stages; correlation problems between the Tethyan and Boreal realms (provinces); and competing standards from the Old and New worlds. Most of these issues have been resolved in the recognition of three Triassic series and seven stages. Further development of the Triassic chronostratigraphic scale needs to focus on definition and characterization of the 15 Triassic substages as these will provide a much more detailed basis for subdivision of Triassic time than do the seven stages.
... This opens philosophical questions on how scientific research develops and can take different paths. Indeed, in the 1960s, 1970s and 1980s of the last century many scientists were aware of the importance of the CPE as a major environmental change and biological turnover, a crucial event from an evolutionary perspective (Angermeier et al., 1963;Kozur, 1972;Schlager, Schöllnberger, 1974;Kozur, 1975;Tollman, 1976;Schroder, 1977;Visscher & Van der Zwan, 1981;Tucker & Benton, 1982;Simms and Ruffell, 1989). ...
Article
In May 2017, in the delightful town of Delmenhorst (Lower Saxony, Germany), the first meeting on the Carnian Pluvial Episode (CPE) was hosted by the Hanse-Wissenschaftskolleg, Institute for Advanced Study. This was a milestone event. For the first time researchers from around the world met to discuss this still poorly known episode of early Late Triassic global environmental and biological change. This thematic set originates from discussions at this first meeting, and includes state-of-the-art research on the CPE, with the most recent discoveries on the complex phenomena that happened during this fascinating interval in Earth’s history.
... The most striking example is in the Germanic Basin, where the semi-playa-like facies of evaporite-bearing clay-rich Keuper formations were temporarily disrupted by a sand-rich braided-river system depositing the thick Stuttgart (Schilfsandstein) Formation (e.g., Kozur and Bachmann, 2010;Shuckla et al., 2010). These fluvial sands of the "Wet Intermezzo" are correlated by conchostracan and megaspore assemblages to marine deposits of the uppermost Julian substage (upper Austrotrachyceras austriacum ammonite Zone) (e.g., Kozur and Bachmann, 2010;Kozur, 1975). The playa-lacustrine-evaporitic fine-grained sediments of the Keuper facies resume at the Julian/Tuvalian boundary (see Fig. 3). ...
Article
Full-text available
Approximately 230 million years ago in the middle of the Carnian stage of the Upper Triassic, the sedimentary records in different regional basins display dramatic changes. Tropical carbonate platforms abruptly ended, and engorged river systems left widespread sand-rich layers across inland basins and coastal regions. This pulse lasted less than a million years in some basins, but constituted a permanent shift in others. Following this event, the Late Carnian has the earliest record of significant dinosaurs on land and the emergence of the calcareous nannoplankton in the oceans that now govern Earth’s carbon cycle. This “most distinctive climate change within the Triassic” has been interpreted by some geoscientists as a global disruption of the Earth’s land-ocean-biological system. The eruption of the Wrangellia large igneous province may have been the trigger for a sudden carbon-dioxide-induced warming and associated increased rainfall in some of these regions. Indeed, some workers have proposed that this “wet intermezzo” warming event is a useful analog to aid in predicting the effects of our future greenhouse on land ecosystems and ocean chemistry. However, the understanding of the onset, duration, global impacts and relatively rapid termination of this postulated warming pulse has been hindered by lack of a global dataset with inter-calibrated terrestrial and marine biostratigraphy, precise radio-isotopic ages, stable isotope records of temperature and the carbon system, and cycle-calibrated rates of regional and global change.
Article
Full-text available
Conchostracans or clam shrimp (order Conchostraca Sars) are arthropods with a carapace consisting of two chitinous lateral valves. Triassic conchostracans range in size from 2 to 12.5 mm long and are common in deposits that formed in fresh water lakes, isolated ponds and brackish areas. Their dessication-and freeze-resistant eggs can be dispersed by wind over long distances. Therefore many conchostracan species are distributed throughout the entire north-ern hemisphere. In the Late Permian to Middle Triassic interval, several of these forms are also found in Gondwana. Many wide-ranging conchostracan species have short stratigraphic ranges, making them excellent guide forms for subdivision of Triassic time and for long-range correlations. The stratigraphic resolution that can be achieved with conchostracan zones is often as high as for ammonoid and conodont zones found in pelagic marine deposits. This makes con-chostracans the most useful group available for biostratigraphic subdivision and correlation in continental lake deposits. Upper Triassic Gondwanan conchostracan faunas are different from conchostracan faunas of the northern hemisphere. In the Norian, some slight provincialism can be observed even within the northern hemisphere. For example, the Sevatian Redondestheria seems to be restricted to North America and Acadiestheriella n. gen. so far has been found only in the Sevatian deposits from the Fundy Basin of southeastern Canada. Here we establish a con-chostracan zonation for the Changhsingian (Late Permian) to Hettangian (Early Jurassic) of the northern hemisphere that, for the most part, is very well correlated with the marine scale. This zona-tion is especially robust for the Changhsingian to early Anisian, late Ladinian to Cordevolian and Rhaetian to Hettangian intervals. For most of the Middle and Upper Triassic, this zonation is still preliminary. Five new genera, six new species and a new subspecies of conchostracans are described that are stratigraphically important. Half of the eight stage boundaries of the Triassic have been defined by a bio-event within a marine Global Stratotype and Point (GSSP) locality, and these definitions have been accepted by both the International Subcommission on Triassic Stratigra-phy and the International Commission on Stratigra-phy. The remaining four stage boundaries are nearing final definition. In the Lower Triassic, both the base of the Induan (priority: Brahmanian) Stage (¼ base of Triassic) and the base of the next younger Olenekian Stage have been firmly defined. In the Middle Triassic, there is wide agree-ment that the defining species for the base of the Anisian Stage should be Chiosella timorensis in the GSSP candidate site at Desli Caira (Romania), but there has not yet been a formal vote on this. The base of the overlying Ladinian Stage, however, has been firmly defined. In the Upper Triassic, the base of the Carnian has been firmly likewise defined, but there is not yet a final defi-nition for the boundaries of the overlying Norian and Rhaetian stages. A consensus has not been reached on a defining species for the base of the Norian or its GSSP locality, but all of the different proposals under consideration do at least fall within a rather narrow stratigraphic interval. For the base of the Rhaetian, Misikella posthernsteini Kozur & Mock has been chosen as the defining species by the International Working Group on the Rhaetian stage, and the GSSP candidate locality at Steinbergkogel (Austria) has been studied in detail by a group under the leadership of L. Krystyn (Vienna) and presented to the participants of the International Conference on 'Upper Triassic Sub-divisions, Zonations and Events' in Bad Goisern in the autumn of 2008. The base of the overlying Hettangian stage (¼ base of the Jurassic) has been defined (so far only by a working group) as the FAD (First Appearance Datum) of Psiloceras spelae Guex, Taylor, Rakus & Bucher. The final definition of the Triassic stages within marine GSSP sections will be completed in the near future, but more than 50% of known Triassic rocks are of continental origin. Therefore, the main task of Triassic stratigraphers in the future will be subdivid-ing and correlating terrestrial strata, both between
Article
Full-text available
The conodont Chiosella timorensis (Nogami, 1968) has for a long time been considered to be a suitable biotic proxy for the Olenekian-Anisian/Early-Middle Triassic boundary. The recently acquired ammonoid record around that boundary clearly shows that the FAD of this conodont is located well below the boundary, i.e., in the late Spathian. In the present paper, it is underlined that the conodont Chiosella timorensis was promoted as a proxy for the nominated boundary in the early 1980s when the ammonoid record around the boundary was not yet well established. On the other side, until the mid 1990s the taxonomic definition and the lineage of the conodont Chiosella timorensis were not well stated, and even now there are still controversial interpretations of the taxonomic content of this conodont species. The new data achieved from the ammonoid/conodont record around the nominated boundary, especially in the western USA, and also in the Deşli Caira section in Romania, firmly demonstrate that the conodont Chiosella timorensis is a defunct proxy for the Olenekian-Anisian/Early-Middle Triassic boundary. As a consequence, the present data on the ammonoid-documented Olenekian-Anisian/Early-Middle Triassic boundary requires the recalibration of all physical events that have been tied to the FAD of the conodont Chiosella timorensis. The case of the Albanian Kçira-section, for which the chronostratigraphic interpretation of the ammonoid record is proved incorrect, definitely makes the conodont Chiosella timorensis a defunct proxy for the nominated boundary. Also, the case of the two Chinese sections recently proposed as being "exceptional" GSSP candidates for the Early-Middle Triassic boundary, which is based on an inconsistent ammonoid/conodont biochronology, fully strengthens this conclusion. The history of the controversial usage of the conodont species Chiosella timorensis in defining the Olenekian-Anisian boundary justifies a discussion about the usefulness of conodonts in the chronostratigraphic calibration of the standard Triassic timescale. One may conclude that the conodonts are not qualified, and have not a reasonable potential, to be used to define or to redefine the boundaries of chronostratigraphic units in the standard Triassic timescale, which have been basically defined on ammonoid biochronology.
Article
For the timespan from 300 Ma to 200 Ma the numerical ages for the 17 global stages Gzhelian to Rhaetian and the five groups Rotliegend, Zechstein, Buntsandstein, Muschelkalk and Keuper of the Central European standard succession are estimated by means of integrated isotope-geochronometric data, weigthed average thicknesses, orbitally tuned sedimentary cycles and biostratigraphic and magnetostratigraphic correlations.For the Stratigraphische Tabelle von Deutschland 2002 (STD 2002), 230 time slices, bundled into 33 quasi isochronous "Folgen", are established. In the STD 2002 the latter have been estimated to have between ca. 0.5 m.y. and ca. 3.5 m.y. (rounded to 0.5 m.y.) durations using cycles of ca. 0.4 m.y. or ca. 0.1 m.y. duration. However, there are still significant possibilities for improved calibrations. A duration of ≥0.5 m.y. is proposed for large gaps in the Rotliegend and Keuper.Thus, the duration of the Induan (Indusian) of ca. 2.0 m.y. in the STD 2002 is set at ca. 1.5 m.y. and of the Olenekian at ca. 3.6 m.y. The Roadium is estimated to ca. 3.5 (or 3.0) m.y., the Wordium to ca. 3.5 (or 3.0) m.y., the Capitanian to ca. 3,0 (oder 4,0) Ma, the Wuchiapingian to ca. 6.4 (or 6.9) m.y., the Changhsingian to ca. 3.1 m.y., the Anisian to ca. 6.4 m.y. (including the Agean substage with ca. 0.3 m.y.), the Ladinian (base: curionii zone) to ca. 4.0 m.y., the Carnian to ca. 12.0 m.y., and the Permian-Triassic boundary at ca. 252.5 Ma.After taking into consideration the detected unconformities, the Keuper and Rotliegend have very similar durations of ca. 40.0 m.y. The Keuper is twice as long as the Muschelkalk, Buntsandstein, and Zechstein together. The latter three are less than 7 m.y. each.In the Southern Alps the 619–745 (Zühlke et al. 2003) were, according to our cyclostratigraphic calibration of the Germanic Trias, accumulated in a time span of no more than 2.6 m.y. Thus, such cycles are of a sub-Milankovitch duration, averaging
Article
Full-text available
In the Stratigraphic Table of Germany 2002 (STG 2002), the Muschelkalk Group is lithostratigraphically subdivided in the Lower Muschelkalk, the Middle Muschelkalk and the Upper Muschelkalk Subgroups, each comprising several formations. Marginal facies with different lithologies are ranked as Formations. Due to the paleogeographic position, most of them are restricted to Southern Germany. Additionally, an allostratigraphic subdivision is established comprising the nine 'Folgen' m1-m9, some of them with 'Subfolgen'. The Folgen represent time intervals bounded by nearly isochronous marker beds. The lower and upper boundaries of the Muschelkalk Group are both defined in terms of lithostratigraphy and allostratigraphy by marker beds. Due to the east-west transgression of the Muschelkalk sea, the lower boundary of the Muschelkalk in Poland is older than that in Germany. Major intervals of non-deposition or erosion have not been identified in the Muschelkalk of Germany; however, short-time gaps comprising not more than one parasequence (100 ka) have been found. Biozonal schemes of different groups of index fossils are used as controlling tools for the lithostratigraphic subdivision, the correlation with the Middle Triassic of the Tethyan realm, and the chronostratigraphic calibration of the Muschelkalk Group. German In der Stratigraphischen Tabelle von Deutschland 2002 (STD 2002) ist die Muschelkalk-Gruppe lithostratigraphisch in die Subgruppen Unterer, Mittlerer und Oberer Muschelkalk mit jeweils mehreren Formationen gegliedert. Lithologisch abweichende Randfazien erhalten den Rang von Formationen; sie treten entsprechend der paläogeographischen Lage fast ausschließlich im süddeutschen Teilbecken auf. Daneben wird eine allostratigraphische Gliederung in die neun Folgen m1 bis m9, darunter einige mit mehreren Subfolgen, etabliert; sie repräsentieren Zeitscheiben, die durch nahezu isochrone Leitbänke markiert sind. Die Unter- und Obergrenze des Muschelkalks, die beide sowohl lithostratigraphisch als auch leitbankstratigraphisch definiert sind, werden diskutiert. Bedingt durch die Muschelkalk-Transgression von Ost nach West wird die Muschelkalk-Untergrenze in Polen tiefer als in Deutschland gezogen. Größere Zeitlücken lassen sich im Muschelkalk Deutschlands nicht belegen; belegbare Zeitlücken umfassen nicht mehr als eine Parasequenz (100 ka). Biostratigraphische Zonierungen anhand verschiedener Indexfossilgruppen erlauben eine Kontrolle der lithostratigraphischen Gliederung, die Anbindung an die tethyale Mitteltrias und damit die chronostratigraphische Einstufung des Muschelkalks.
Article
The holotype ofAnarosaurus multidentatus von Huene (1958) from the lowermost Anisian of the Austrian Alps is redescribed and referred to the genusCymatosaurus. Eusauropterygian characters shared byA. multidentatus are the elongated and broadened Symphysis, and the contours of the lower jaw suggesting the presence of a constricted snout. Morphological details of the lower jaw Symphysis showA. multidentatus to be close toCymatosaurus among stem-group sauropterygians.Cymatosaurus multidentatus is the only representative of its genus known so far from the Alpine Triassic, and it represents the earliest known sauropterygian from the Alpine Triassic. Der Holotypus vonAnarosaurus multidentatus von Huene (1958) aus dem untersten Anis des Arlbergs wird neu beschrieben und zur GattungCymatosaurus gestellt. Abgeleitete Merkmale, welcheA. multidentatus mit den Eusauropterygia gemeinsam hat, sind die verbreiterte Unterkiefersymphyse und die eingeschnürte Schnauze, die sich im Umriß des Unterkiefers spiegelt. Morphologische Merkmale der Unterkiefersymphyse weisenA. multidentatus als Vertreter vonCymatosaurus aus.Cymatosaurus multidentatus ist der einzige bislang bekannte Vertreter dieser Gattung aus der alpinen Trias und ist zugleich der geologisch älteste Sauropterygier aus der alpinen Trias.
Article
Kurze bersicht ber palogeographische, palotektonische und paloklimatologische Probleme der Trias, unter Ausklammerung des Germanischen Beckens; allgemeiner Rahmen zu den Referaten der Trias-Tagung 1982 in Wrzburg.Short review of paleogeographic, paleotectonic and paleoclimatological problems of the Triassic system, outside of the Germanic Basin. General framework to the papers presented at the 1982 symposium on the Triassic.Brve vue d'ensemble des problmes palogographiques, palotectoniques et paloclimatiques du Trias, en dehors du bassin germanique. Cadre gnral des communications prsentes lors du symposium sur le Trias de 1982. , , .
Chapter
Middle Muschelkalk of the eastern Paris Basin is an extension of the large German Basin than an unit by itself. It allows us to study the effects of continental influences on evaporitic sedimentation: fresh water and detrital supplies, and salt dissolution. More or less evaporated sea water flowing into the basin causes a cyclic evolution of salinity throughout the series. The deposit is generally layered and shows millimetric to centimetric primary depositional sequences which prove the complexity of the internal organization of the filling in the basin. They reflect elementary changes in the depositional environment: fresh water supplies carring detrital particles, fresh water and sea water inflow introducing dilution, increasing evaporation rate causing precipitation of carbonates, Ca-sulfate or halite. In fact, the main factors controlling sedimentation which are working at this fine scale and the evolution at a larger sequential scale depends upon which one of these factors becomes dominant. The general evolution results in a typical sedimentary cycle. The structural behavior of the Hercynian basement controls distribution and sometimes preservation of the depsits. Diagenesis may also preserve or totally destory primary sedimentary structures. Algal mat-like deposits undergo extensive Ca-sulfate diagenesis in the middle of the sedimentary cycle and toward its top, dolomites and magnesium-rich corrensites develop layer by layer. Middle Muschelkalk of the eastern Paris Basin is a very good example for the study of sedimentary processes involoved on the edges of a large evaporitic basin.
Article
The sequence stratigraphic methodology can be readily applied to the cratonic basin-fill of the classic German Triassic, consisting of shallow-marine to terrestrial mixed carbonate/siliclastic rocks. The whole Triassic succession represents a second-order transgression/regression cycle, built by third-order depositional sequences, systems tracts, and parasequences. Many bounding surfaces represent widely used marker beds, long used in classical lithostratigraphy.Using a synthesis of outcrop, well-log and literature data on stratal geometry, facies, cycle stacking patterns and paleogeography, a regional chart of coastal onlap was constructed. Within the limitations of the presently available biostratigraphic data, the observed cycles appear to correlate fairly well with those in other areas, but include a number of additional sequences not included in the Haq et al. (1988) chart. Comparative analysis of regional onlap curves from different, globally spread Triassic basins, together with an improved biostratigraphy will be necessary to relate the accommodation changes to eustatic versus tectonic and climatic controls and to produce a refined eustatic chart. The German Basin could provide a favourable reference point for such an analysis.
Book
Sedimentary basins host, among others, most of our energy and fresh-water resources: they can be regarded as large geo-reactors in which many physical and chemical processes interact. Their complexity can only be well understood in well-organized interdisciplinary co-operations. This book documents how researchers from different geo-scientific disciplines have jointly analysed the structural, thermal, and sedimentary evolution as well as fluid dynamics of a complex sedimentary basin system which has experienced a variety of activation and reactivation impulses as well as intense salt tectonics. In this book we have summarized our geological, geophysical and geochemical understanding of some of the most important processes affecting sedimentary basins in general and our view on the evolution of one of the largest, best explored and most complex continental sedimentary basins on Earth: The Central European Basin System.
Article
The Stuttgart Formation (Schilfsandstein) is approximately 50 m thick in Thuringia, representing deposition during the “Mid-Carnian Wet Intermezzo”. Stratigraphically it occurs between the Grabfeld and Weser formations, which formed under arid conditions. It comprises NNE–SSW-trending elongate, anastomosing channelized sand-rich bodies with erosional bases (channel belts) that are several kilometres wide and pass laterally into predominantly mudstones deposited in interfluve areas. The source area of these clastics was the uplifted Norwegian Caledonides. Muddy interfluve facies is dominant in exposures in Thuringia, Central Germany.
Article
Full-text available
By identifying and separating the regional and local components of successive palynological assemblages from the Estherienschichten, Schilfsandstein and Lehrbergschichten in southern Germany, it is demonstrated that during Late Triassic (Carnian) times the regional vegetation remained consistently dominated by xerophytic conifers, indicative of arid climatic conditions. In the Schilfsandstein, the predominant bennettitalean and pteridophytic elements represent a much more locally derived component, corresponding to a variety of vegetation types growing on permanently moist, wet or water-saturated substrates. Widespread but local humid environmental conditions should be ascribed to high groundwater tables in a fluvial depositionary setting, rather than to a climatically induced “pluvial event”.
Article
The Triassic stratigraphy and facies of the four major terranes of the Alpine-Carpathian region is shortly described and illustrated by schematic stratigraphic charts. The main stratigraphical features of the terranes are compared to those of the neighbouring epicontinental regions (Europe and North Africa) and the Aegean region, representing the Tethyan domain. The detailed ammonoid biostratigraphical subdivision developed in the Alpine region is also correlated with the neighbouring regions. The paleogeographical positions of the terranes are briefly discussed. It is concluded that the crustal fragments carrying the later Alpine-Carpathian terranes were in close connection with the Eurasian continental shelf in the Triassic, while during the Jurassic they belonged to different microcontinents within the western Tethys ocean.
Article
Full-text available
The deposition of the Stuttgart Formation ('Schilfsandstein'), commonly considered type-example of the Carnian Pluvial Event, was controlled by high frequent 4th order sequences that resulted in pre-, intra- and post-Schilfsandstein transgressions from Tethyan waters into the epicontinental Central European Basin (CEB). The pre-Schilfsandstein transgression flooded the CEB trough gates to the Southeast and resulted in a wide-spread inland sea that was characterised by increased biological productivity, predominantly oxic conditions and enabled the immigration of euryhaline marine fauna with plankton, ostracodes, fishes, bivalves and the gastropods Omphaloptychia suebica n. sp. and Settsassia stuttgartica n. sp. The rather short-term intra- and post-Schilfsandstein transgressions flooded the CEB from the Southwest and Southeast and established a shallow brackish inland sea that stretched up to North Germany. Both, 4th and 3rd order sequences derived from the succession in the CEB correlate well with those derived from successions of NW Palaeotethyan and SW Neotethyan shelfs. Therefore pronounced circum-Tethyan eustatic cycles are evidenced and may have had considerable impact on prominent middle Carnian events: Reingraben turnover, Carnian Pluvial Event, Carnian Crisis and Mid Carnian Wet Intermezzo. The broad circum-Tethyan evidence of 106-year scale cycles suggest glacioeustatic sea-level changes even in the Triassic Greenhouse period.
Article
Full-text available
The Stuttgart Formation (Schilfsandstein, Middle Keuper) near Iphofen (Unterfranken/ Lower Franconia) is some 15 in thick and consists of fluvial and estuarine sediments, which are unconformably entrenched in the underlying shales of the Grabfeld Formation. An approximately 8 in thick sand body in the lower part exhibits bipolar herringbone cross-bedding, sigmoidal bedding with double mudstone drapes, tidal bundles and polymodal paleocurrents. These structures suggest intertidal bars and tidal channels dominated by microtidal activity towards an estuary mouth beyond the zone of turbidity maxima. Appreciable wave effect and wave induced currents were instrumental for sedimentation, too. The succession represents a transgressive systems tract generated during relative sea-level rise in a drowned river valley system.
Article
Full-text available
This chapter discusses paleobiogeography of middle Triassic sauropterygia in Central and Western Europe. An isolated eusauropterygian vertebral neural arch (MHI 1279) was found in the Formazione a gracilis near Recoaro, Val Camonda, above the classical Dadocrinus site Cava di Gesso, in the Vicentinian Alps. The zygosphene is an accessory articular process located between the prezygapophyses. It has been found that in MHI 1279, the zygosphene is fully divided by a deep anterior indentation. The zygantrum is a depression in the base of the neural arch located between the postzygapophyses and receiving the zygosphene from the successive vertebra. In Nothosaurus, the zygantrum is subdivided by a thin medial vertical septum. It is observed that in spite of the deep subdivision of the zygosphene, this vertical septum is absent in the zygantrum in MHI 1279. Further, it has been suggested that neural arches, different from those of Nothosaurus and similar in morphological detail to MHI 1279, can be reported from other lower Muschelkalk localities in the central part of the Germanic Basin.
Article
Full-text available
From 1989 to 1994 a series of papers outlined evidence for a brief episode of climate change from arid to humid, and then back to arid, during the Carnian Stage of the late Triassic Epoch. This time of climate change was compared to marine and terrestrial biotic changes, mainly extinction and then radiation of flora and fauna. Subsequently termed, albeit incorrectly, the Carnian Pluvial Event (CPE) by successive authors, interest in this episode of climatic change has increased steadily, with new evidence being published as well as several challenges to the theory. The exact nature of this humid episode, whether reflecting widespread precipitation or more local effects, as well as its ultimate cause, remains equivocal. Bed-by-bed sampling of the Carnian in the Southern Alps (Dolomites) shows the episode began with a negative carbon isotope excursion that lasted for only part of one ammonoid zone ( A. austriacum ). However, that the Carnian Humid Episode represents a significantly longer period, both environmentally and biotically, is irrefutable. The evidence is strongest in the European, Middle Eastern, Himalayan, North American and Japanese successions, but not always so clear in South America, Antarctica and Australia. The eruption of the Wrangellia Large Igneous Province and global warming (causing increased evaporation in the Tethyan and Panthalassic oceans) are suggested as causes for the humid episode.
Article
The Keuper group of the Germanic Basin consists of Middle to Late Triassic sediments, most of them developed in continental facies. The stratigraphic succession is dominated by varicoloured red, green, and grey lacustrine claystones, mudstones and marls with intercalations of evaporite and carbonate beds. Fluvial sandstones interfinger with these basinal facies near the basin margins. They have been shed from scandinavian provenance areas, from the Vindelician-Bohemian Massif and to a minor extent from the Ardennes. At two distinct stratigraphic levels sandstones from Scandinavia spread over all of the Basin. In the Lower and Middle Keuper, marine sediments are only present in the southern part of the Basin. They are restricted to few thin carbonate beds and some estuarine channel deposits. In the Upper Keuper, marine sandstones and mudstones do only occur in the western part of the basin and are restricted to the stratigraphic level of the "contorta-beds". The thickness of the Keuper Group is about 200 to 600 meters over most of the outcrop areas of southern and middle Germany. In most of northern Germany, Keuper deposits are covered but known from many boreholes to be about 500 to 700 meters thick. Some Graben structures beneath northern Germany, however, received more than 1000 meters of Keuper sediments. The maximum thickness of more than 5000 meters has been documented in the Glückstadt Graben beneath the German Bight. Keuper stratigraphy has been explored for nearly two hundred years. Owing to the federal political subdivision of Germany, the regional geological surveys of Germany have developed different stratigraphical systems which are rather confusing for anyone but specialists. The Keuper working group of the German Stratigraphic Commission therefore elaborated a common national lithostratigraphic scheme. This scheme is presented in this volume. The scope of this new lithostratigraphic nomenclature is to support and simplificate correlation over all of Germany and to the Keuper stratigraphy of adjacent countries. The complex stratigraphic architecture of the Keuper Group needs to be described by a set of complementary subdivisions based on different stratigraphic methods. Only in combination with each other do these different aspects merge to an appropriate representation of Keuper stratigraphy. Biostratigraphically, all stages and substages from the Late Ladinian to the Rhaetian are documented within the Keuper Group. The only recognizable gap is indicated for the Lacian substage (early Norian). Keuper biostratigraphy is mainly based on palynomorphs, tetrapods, bivalves, cephalopods, and ostracods. Other groups may prove to be useful by further studies (i.e., plant fossils, fishes, conchostacans, gastropods). Lithostratigraphy allows subdivision of the German Keuper Group into a number of mappable formations. For the basinal facies zone, which is present in most of Germany, six formations are defined herein (from bottom to top): the Erfurt, Grabfeld, Stuttgart, Weser, Amstadt, and Exter formations. At the southeastern fringe of the basin, the vindelician marginal facies zone is subdivided into eight formations: the Grafenwöhr (including a Muschelkalk equivalent in its lower part), Benk, Steigerwald, Hassberge, Mainhardt, Löwenstein, and Trossingen Formations, as well as a marginal equivalent of the Exter Formation not named yet. These national lithostratigraphic units are defined parallel to the traditional units of the politically confined regions as a supplementary tool for their correlation. Unconformities a re present at formation boundaries as well as within nearly all formations. At least seven unconformities can be traced across most of the basin and may be indicators of significant hiatuses. Nine and possibly more unconformities can be recognized on a local to regional scale. Key beds and marker surfaces belong to the fundamentals of Keuper stratigraphy for more than a hundred years. In addition to the basin-wide unconformities, carbonate and anhydrite beds as well as halite strata are used to define six almost isochronous "Folgen" (singular: "Folge"). These Folgen provide a time-referenced allostratigraphic framework supplementing and elucidating the facies boundaries of the lithologically defined formations. Cyclostratigraphy of the Keuper Group is based on a large number of sedimentological studies and allows the distinction of a set of hierarchically structured cycles of different dimensions. Five major cycles, of a duration of several millions of years, are each subdivided by several paracycles with a mean duration of about 100 to 400 ka. Many of these Paracycles are correlatable over distances of several hundreds of kilometers. The Paracycles in turn consist of numerous even smaller genetic cycles of rather local extent and a time equivalent of probably about 10 to 20 ka. First steps of sequence stratigraphy have been made. The present concepts, however, significantly differ from each other and are based only on parts of the basin. The present volume is organized in two main parts: general aspects of the german Keuper Group are presented in in the first section (chapters 2 to 4), whereas the second section (chapter 5 to 6) of this volume is dedicated to detailed descriptions of regional stratigraphy, the correlation of these regional subdivisions to the national scheme, and the correlation of the german Keuper to our neighbouring countries.
Article
Full-text available
Geographical Information Systems (GIS) have been applied extensively to analyse spatial data relating to varied environmental issues, but have not so far been used to address biostratigraphical or macroevolutionary questions over extended spatial and temporal scales. Here, we use GIS techniques to test the stability, validity and utility of proposed Middle and Late Triassic (LVFs), a global biostratigraphical framework based upon terrestrial/freshwater tetrapod occurrences. A database of tetrapod and megafloral localities was constructed for North America and Western Europe that also incorporated information on relevant palaeoenvironmental variables. This database was subjected to various spatial analysis techniques. Our GIS analysis found support at a global level for Eocyclotosaurus as an Anisian index taxon and probably Aetosaurus as a Norian indicator. Other tetrapod taxa are useful biostratigraphical/biochronological markers on a regional basis, such as Longosuchus and Doswellia for Late Carnian time. Other potential index fossils are hampered, however, by taxonomic instability (Mastodonsaurus, Metoposaurus, Typothorax, Paleorhinus, Pseudopalatus, Redondasaurus, Redondasuchus) and/or are not clearly restricted in temporal distribution (Paleorhinus, Angistorhinus, Stagonolepis, Metoposaurus and Rutiodon). This leads to instability in LVF diagnosis. We found only in the western Northern Hemisphere is there some evidence for an Anisian–Ladinian biochronological unit amalgamating the Perovkan and Berdyankian LVFs, and a possible late Carnian unit integrating the Otischalkian and Adamanian.
ResearchGate has not been able to resolve any references for this publication.