Palynological zonation and particulate organic matter ...

Review of Palaeobotany and Palynology 218 (2015) 28–47

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Palynological zonation and particulate organic matter of the Middle Triassic of the Southern Alps (Seceda and Val Gola–Margon sections, Northern Italy) Peter A. Hochuli a,⁎, Guido Roghi b, Peter Brack c a b c

Palaeontological Institute and Museum, Univ. Zürich, Karl Schmid-Str.4, CH-8006 Zürich, Switzerland Institute of Geoscience and Earth Resource, CNR, Via Gradenigo 6, Padova, Italy Departement Erdwissenschaften, ETH Zürich, CH-8092 Zürich, Switzerland

a r t i c l e

i n f o

Article history: Received 19 December 2013 Received in revised form 24 June 2014 Accepted 2 July 2014 Available online 26 August 2014 Keywords: Middle Triassic Southern Alps Stratigraphy Palynology Palynofacies

a b s t r a c t Based on the palynological study of the Seceda core drilled in the north-western Dolomites and of an outcrop section from Val Gola–Margon (Southern Alps, Northern Italy) we propose a new palynostratigraphic subdivision of the Middle Triassic of the Western Tethyan realm. The six new zones (TrS-A–TrS-F) cover the interval between the late Anisian (Illyrian) and the late Ladinian (Longobardian). The zonation is based on the first and last appearances of individual taxa as well as on the quantitative distribution of major groups of sporomorphs. The presented palynological succession is directly correlated with the precise biostratigraphic, magnetostratigraphic and chronostratigraphic framework of the Seceda section, which represents the principal auxiliary global stratotype section and point (GSSP) section of the Ladinian stage. As an additional record we use the data of Van der Eem (1983) newly calibrated using the detailed lithostratigraphic scheme of the Seceda section and the GSSP section from Bagolino. The reassessment of the data from the late Anisian and the Ladinian of Van der Eem (1983) and Brugman (1986) shows earlier occurrences of some of the major pollen groups, and results in more precise correlations with other areas. The overlapping ranges of the palynological phases and subphases proposed by Van der Eem (1983) and Brugman (1986) make some of these phases obsolete. Within the studied interval the distribution of sporomorphs shows some major changes such as a major reduction of pteridosperms (e.g. taeniate bisaccate pollen), which are abundant in the lower part of the section (zone TrS-A) and are subsequently replaced by conifers (e.g. Triadispora, Ovalipollis and Circumpolles). Palynofacies studies show that the relatively high amount of fluorescent amorphous organic matter (AOM) reflects dysoxic conditions in the lowermost part of the section (“Plattenkalke”). The change in palynofacies between the “Plattenkalke” and the “Knollenkalke” corresponds to a marked change in the depositional environment from dysoxic to well oxygenated conditions in the “Knollenkalke”. In contrast to this, the succession of palynofacies from the “Knollenkalke” to the “Breccias” suggests a continuity of depositional environments reflecting a slight reduction of the oxic conditions. The light coloured pollen grains show no sign of thermal alteration of the organic matter. © 2014 Elsevier B.V. All rights reserved.

1. Introduction The Southern Alps (Fig. 1) represent one of the classical areas for the study of Triassic geology. Spectacular outcrops allow an exceptional insight into the genesis of Middle–Upper Triassic carbonate platforms and adjacent basins. Since the late 19th century South Alpine areas have been used to define Triassic stratigraphy (e.g. Richthofen, 1860; Mojsisovics, 1879, 1882; Mojsisovics et al., 1895; Bittner, 1892; Brack et al., 2005; Mietto et al., 2012). Additionally the depositional mode and the timing of rhythmic sedimentation in Middle Triassic platform ⁎ Corresponding author. E-mail addresses: [email protected] (P.A. Hochuli), [email protected] (G. Roghi), [email protected] (P. Brack).

http://dx.doi.org/10.1016/j.revpalbo.2014.07.006 0034-6667/© 2014 Elsevier B.V. All rights reserved.

carbonates at Latemar in the Dolomites have been extensively discussed (e.g. Goldhammer et al., 1990, 1993; Brack et al., 1996; Preto et al., 2001; Zühlke et al., 2003; Kent et al., 2004). The bedding patterns in the coeval basinal Buchenstein (Livinallongo) Formation of the same area have also been evaluated in terms of orbital forcing (Mauer et al., 2004; Spahn et al., 2012). Thus, the stratigraphic resolution and precise correlation of lithologically different Middle Triassic sediments became truly critical issues. The integration of information from numerous well-correlated basinal sections throughout the Southern Alps has resulted in a reliable biostratigraphic framework (ammonoids, bivalves (Daonella), and conodonts) especially for the Anisian–Ladinian boundary interval (Brack and Rieber, 1993; Brack and Muttoni, 2000; Muttoni et al., 2004). This framework is tied to radio-isotope age data and to the succession of magnetic reversals (Mundil et al., 1996; Kent et al., 2004; Brack et al., 2007).

P.A. Hochuli et al. / Review of Palaeobotany and Palynology 218 (2015) 28–47

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Fig. 1. Location of the studied area and sections mentioned in the text. Seceda and Val Gola (this study); sections studied by Van der Eem (1983) are indicated in italics.

Beyond the assessment of stratigraphic cycles these data have provided the framework required for a modern definition of the Anisian–Ladinian boundary. The GSSP of the base of the Ladinian stage is fixed at Bagolino in the western Southern Alps and the Seceda column has been designated as the principal auxiliary section in the Dolomites (Brack et al., 2005). Three decades ago, the main reference for the Middle Triassic palynological record of the low latitude Tethyan realm was obtained from stratigraphic successions in the Southern Alps (Dolomites and Recoaro), complemented with core data from the Balaton Highland of Hungary (Van der Eem, 1983; Brugman, 1986). In his study of palynomorphs from uppermost Anisian to Carnian sediments, Van der Eem (1983) combined results from rather loosely sampled sections and isolated outcrops in the Dolomites. The correlation of the studied sites relied on published age assignments. Thereafter Brugman (1986) extended this record to cover the entire Anisian and the upper part of the Olenekian. In a range chart for palynomorphs of the late Early Triassic to earliest Carnian of the Alpine (Tethyan) realm Brugman (1986, p. 33) included a “somewhat revised version” of the results of Van der Eem (1983). Up till now this chart has remained the standard for the Alpine Triassic palynomorph record and only portions of it have hitherto been revised (e.g. Ladinian–Carnian boundary interval, see Mietto et al., 2012). The recent improvements in the stratigraphic framework for the South Alpine Middle Triassic now provide the opportunity for a reevaluation and new calibration of the results of the pioneering palynological studies of Van der Eem (1983) and Brugman (1986). The combination of macro- and microfossils (conodonts), physical stratigraphy (patterns, tephrastratigraphy) and magnetic reversals (Brack and Muttoni, 2000; Muttoni et al., 2004) allow a reassessment of the stratigraphic succession used by Van der Eem (1983) and indeed results in substantial shifts of the correlated key intervals and outcrops studied by Van der Eem (1983). Moreover, a core drilled for scientific purposes into upper Anisian– Ladinian sediments at Seceda in the north-western Dolomites (Brack et al., 2000) provides the opportunity to assess the palynomorph record in a new and almost undisturbed single succession. This paper documents the results of a palynological study on samples mainly from the Seceda core. Additional data filling a gap in the Seceda record were gained from samples from an outcrop section at Val Gola (near Trento, Northern Italy). The new information is then compared with the data of the repositioned levels of the samples reported by Van der Eem (1983) and a new scheme of palynological

zones is proposed. The combined palynological record represents a long late Anisian–late Ladinian time span of probably slightly over 4 million years. The comparison of our scheme with zonations for the Germanic Basin (Kürschner and Herngreen, 2010; Heunisch, 1999) leads to the recognition of regional differences in the composition of floral assemblages. Such information could be significant for future palaeoenvironmental interpretations and palaeoclimatic analysis of the Middle Triassic. 2. Stratigraphic framework and age calibration In this paper the chronostratigraphy applied to the Buchenstein interval at Seceda basically follows the scheme of Brack et al. (2005, 2007). Although research on Middle Triassic ammonoids and Daonella over the past 25 years resulted in a much improved macrofossil record for the Anisian–Ladinian boundary interval (R. reitzi zone to E. curionii zone), information on younger Ladinian levels of Buchenstein successions is still fragmentary. Although thin-shelled pelagic bivalves of the genus Daonella provide additional constraints for late Ladinian intervals (e.g. Schatz, 2004), relatively large intervals of uncertainty remain between ammonoid zones. These zones also await clear definitions (e.g. “P. gredleri” and P. archelaus zones). For instance, the term “P. gredleri” zone introduced by Krystyn (1983) can be used merely as a label. The index taxon needs revision and the specimens of Trachyceras gredleri originally reported by Mojsisovics (1882) were possibly from younger and older levels than the current homonymous zone. The P. archelaus zone as used in this study includes the layers containing Daonella pichleri. The topmost part of the Seceda column most likely corresponds to a stratigraphic interval with the first occurrences of Frankites regoledanus in the lowermost Wengen Fm. at Bagolino (99.5m level) and Monte Corona in Lombardy and Giudicarie (Brack and Rieber, 1993; Brack et al., 2005). Following Krystyn (1983), Brugman (1986) assigned the “P. gredleri” ammonoid zone to the Longobardian substage. However, its inclusion into the Fassanian more closely matches the original concepts for the substages of the Ladinian as introduced by Mojsisovics et al. (1895, defining: Fassanisch = Buchensteiner Schichten + Marmolatakalk; Longobardisch = Wengener Schichten). Moreover, the subdivision advocated here results in balanced durations of the early and late Ladinian substages.

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In fully developed Buchenstein successions such as at Seceda, layers of silt to sand sized acidic volcaniclastic materials are concentrated in three main intervals, the lower (LPV), middle (MPV) and upper Pietra Verde (UPV), respectively. These ash layers in the Buchenstein Fm. represent not only excellent tools for the correlation of coeval units throughout the Southern and Eastern Alps, but they also yield the potential for precise numeric calibration through radiometric age dating

of magmatic minerals. Mundil et al. (1996) reported the first highresolution U–Pb single zircon ages from four layers, including two from the Buchenstein Fm. at Seceda. Subsequent studies and the application of the (post-2004) CA-ID-TIMS U–Pb dating procedure showed that older datings tend to be slightly too young (for a discussion of Triassic data see Mundil et al., 2010 and references therein). Two levels with accurate CA-ID-TIMS U–Pb data can be safely projected into the

Fig. 2. Lithological log of the Seceda core, the Seceda outcrop and the Val Gola section with ammonoid zones, radiometric ages, and palynological zones.


Buchenstein succession at Seceda: (i) the younger level corresponds to the 239.3 ± 0.2 Ma old ash in the uppermost Reifling Fm. at Flexenpass in the Northern Calcareous Alps (FP-2 of Brühwiler et al., 2007). Because at Flexenpass this bed occurs below layers with Daonella tyrolensis it most likely corresponds with the 40–45 m interval of the Seceda core. (ii) the older level belongs to the Tc-tuff interval at Monte San Giorgio for which Mundil et al. (2010) reported a LA-TIMS U–Pb zircon age of 242.1 ± 0.6 Ma. Using the fit of Brack et al. (2007, fig. 8), the total age span represented by the Seceda core (12–102.55 m interval) has an estimated duration of slightly more than 4 m.y. (ca. 238.2–242.3 Ma). New radiometric ages from the Meride Lst. at Monte San Giorgio also fall within this time span and should correspond to levels of the MPV and the UPV (Stockar et al., 2012). Furthermore all these numeric age constraints are consistent with a recent very precise age of 237.77 ± 0.05 Ma for a volcaniclastic layer in the Wengen succession (Fernazza Fm.) above the Buchenstein Fm. at Seiser Alm, only 10 km south-west of Seceda (Mietto et al., 2012). 2.1. Studied sections The palynological record presented in this paper is based on relatively unaltered material from the continuously cored Seceda section and material from an outcrop succession at Val Gola–Margon near Trento (Fig. 1). Both sections are closely tied to the GSSP for the base of the Ladinian stage at Bagolino in the western Southern Alps (Brack et al., 2005 and references therein). The new palynological data thus represent a unique high-resolution record between the late Anisian (R. reitzi zone) and the late Ladinian (P. archelaus ammonoid zone). The South Alpine successions and fossil records can be correlated in detail with sections in Hungary (Brack et al., 2005) and in the Northern Calcareous Alps of Austria and Liechtenstein (Brühwiler et al., 2007). 2.1.1. Seceda core The stratigraphy of the Buchenstein Fm. as exposed at Seceda and its macrofossils (ammonoids, Daonella) have been documented by Brack and Rieber (1993) and a summary log is shown in Fig. 2. In 1998 the Seceda core was drilled for research purposes (Brack et al., 2000). Detailed core–outcrop comparisons with refined sedimentological and cyclostratigraphic analyses were added by Maurer and Rettori (2002), Maurer and Schlager (2003) and Maurer et al. (2003, 2004). Prominent lithological markers including volcaniclastic layers, sharp lithological breaks, distinct pelagic marker beds and breccia layers provide close ties between the core and the successions visible in steep cliffs as close as 200 m from the Seceda drill site. Based on the same marker horizons along with age-diagnostic fossils and magnetic reversals the Seceda outcrop section has been correlated in detail with Buchenstein successions elsewhere in the Dolomites (Brack and Muttoni, 2000; Muttoni et al., 2004). Correlated sections further afield include Val Gola near Trento, the GSSP of the base of the Ladinian stage at Bagolino (Lombardy) as well as the Anisian–Ladinian succession at Monte San Giorgio (southern Switzerland; Besano Fm.–Meride Lst.; Brack and Rieber, 1993; Stockar et al., 2012). The ages attributed to the Buchenstein Fm. at Seceda as shown in Fig. 2 are based on the integration of macrofossil and conodont data from all these sections. In the following paragraphs a short overview is given of the stratigraphic succession of the Seceda core, which provided the majority of the palynological samples reported here. About 88 m of Buchenstein Fm. was recovered and the basal part of the well penetrated the uppermost portion of the Contrin Formation. The strongly dolomitized shallow water carbonates of the latter unit have not been considered for this study. In the north-western Dolomites the Buchenstein Fm. represents the fill of relatively narrow intra-platform basins that started shallow and rapidly reached maximal depths of several hundred metres. In core and outcrops at Seceda the Buchenstein Fm. comprises four distinct lithostratigraphic units, which are in ascending order the

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“Plattenkalke” (92.15–102.55 m), the “Knollenkalke” (53–92.15 m), the “Bänderkalke” (44–53 m) and the “Breccias” (15–44 m). The “Plattenkalke” are characterised by a succession of evenly bedded, partly laminated dark calcareous or dolomitic mudstones with several cm to dm thick interbeds of volcanoclastic material (acidic ashes). Total organic carbon contents in the limestone layers reach up to a few percent. In the Seceda area the entire interval of the “Plattenkalke” can been attributed to the R. reitzi ammonoid zone (Brack and Rieber, 1993). The overlying “Knollenkalke” consist of nodular, irregularly bedded and intensively bioturbated calcareous mudstones with chert as diffuse patches but also in nodules and bands. Radiolarians and thin shells of bivalves are common pelagic particles. In the lower part of this interval three distinct volcaniclastic layers occur (Tc, Td, and Te) and can be traced over long distances throughout the Dolomites to the western Southern Alps and southern Switzerland (Brack and Rieber, 1993). Within the “Knollenkalke” at Seceda the N. secedensis zone (92.15– 83.7 m) starts with representatives of the ammonoid genus Ticinites at the very base (outcrops). The core interval between 83.7 and 72 m represents the E. curionii zone. The interval 64.5–57 m ascribed to the “P. gredleri” zone comprises a several metres thick conspicuous interval of evenly bedded laminated limestones similar to those of the “Plattenkalke”. In the core a 5–6 metre thick interval between the 60– 59 m levels is missing. The corresponding strata with dm-thick volcaniclastic layers are clearly visible in outcrops located further north (Brack et al., 2000; Maurer and Rettori, 2002). This gap in the core corresponds to the level of expansion of a thick mafic sill outcropping only 600 m to the south-west of the drill site. Above the gap typical nodular limestones continue and at the 55 m core-level a rapid increase of the volume percentage of calcareous turbidites with platform derived debris marks the base of the “Bänderkalke” (Maurer and Schlager, 2003). The transition from the “Bänderkalke” to the “Breccias” is gradual (at around 45 m) and the latter also comprise predominant platform carbonate debris. In the outcrop succession several megabreccias decrease in thickness over a distance of a few hundred metres. However, a single conspicuous bed is much more continuous and characterised by a polygenic composition including debris derived from the “Knollenkalke” and “Bänderkalke” as well as clasts of basaltic lava. This key bed (MB II in Fig. 2) is also clearly visible in the core succession (32–29 m interval). In the uppermost metres of the “Breccias” interval, silt and sand-rich layers occur and may be ascribed to the base of the Wengen Group. On the southern slopes of the Seceda area extrusive basalt is interbedded in the corresponding strata along the western Aschkler Alm and below the Kuka saddle (Brack et al., 2000). The level of onset of mafic volcanism at Seceda corresponds to a core depth of ca. 35.5 m. 2.1.2. Val Gola–Margon section The Val Gola–Margon section is situated on the steep western flanks of the Adige valley, near Trento (Trentino, Northern Italy) (Fig. 1). In the past this section was well exposed along a creek and had been studied since the early 20th century (e.g. Arthaber, 1916). Presently it is only partly accessible. The discontinuously exposed section ranges from the late Early Triassic up to the early Carnian (De Zanche and Mietto, 1989). The Middle Triassic part of the succession comprises basinal sediments belonging to the “Zwischenbildungen” complex (De Zanche and Mietto, 1986). In the Adige valley the “Zwischenbildungen” are composed of the dark “Margon Limestone” at their base. This limestone interval is overlain by silty marls alternating with silty calcarenites and pelites (“Val di Centa Marls”), and these in turn by limestones and cherty nodular limestones and thin pelites interlayer with radiolarians and pelecypods (“Val Gola Limestone”) (De Zanche and Mietto, 1989; Gianolla et al., 1998). Lithologically the Val Gola Lst. is identical with the “Knollenkalke” of the Buchenstein Formation. Middle Triassic ammonoids have long been known from Val Gola (Arthaber, 1916). Brack and Rieber (1986, 1993) reported a log of the original section with the distribution of ammonoids and Daonella of

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the Anisian–Ladinian boundary interval. In a study on palynomorphs, Roghi (1997) largely confirmed the distribution of ammonoids and the position of the base of the E. curionii zone. Magnetic reversals in the Val Gola succession (Gialanella et al., 2001) and ammonoids provide safe ties to the Anisian–Ladinian boundary interval at Seceda (Brack et al., 2001; Muttoni et al., 2004). Ammonoids and Daonella (D. elongata group) also constrain the interval sampled for palynological analysis to the N. secedensis zone.

2.1.3. Recalibrated sections studied by Van der Eem (1983) The palynological samples studied by Van der Eem (1983) that overlap with the cored interval at Seceda come from the following six localities: Bulla (Pufels, 8 samples (Puf); Caprile, 9 samples (Cap); Moena (1 sample); Pieve (2 samples); Aschkler, 4 samples (Ask); Pana, 5 samples (Pan). The other samples of Van der Eem's (1983) study are from younger Ladinian levels such as those from the upper part of the Bulla section, from the Grohmann section and from sections reaching Carnian levels (Stuores, Settsass, Heiligkreuz). Of the six intervals corresponding to the Seceda core, the Aschkler and the Pana sections are in the Seceda area, at distances of 1 km and ca. 300 m, respectively, from the core site (for a detailed map see fig. 2, in Brack et al., 2000). Prominent layers with Daonella pichleri and Daonella tyrolensis as well as volcaniclastic markers provide reliable

ties between the Aschkler interval and the Seceda outcrop section and the core. Basalt layers (including pillow lavas) are exposed between Mastlé and the Kuka saddle (including the Aschkler section; see Table V in Van der Eem, 1983) but rapidly pinch out towards the Seceda core site. The stratigraphic position corresponding to the extrusive basalts is indicated in Fig. 2. The section Pana 1-08 corresponds to the “Breccias” interval straddling the conspicuous Megabreccia Bed II that has also been identified in the core (Brack et al., 2000). The sandy to shaley intercalations between the platform slope carbonates (mega)breccias at Pana represent the upslope terminations of siliciclastic beds assigned to the Wengen succession at Aschkler (Ask D–E). The single sample from locality Pana 1-07 is not considered here, but it most likely corresponds to the 25–35 m-interval of the Seceda core as well. The principal section studied by Van der Eem (1983) at Bulla (Pufels) is located between Seceda and Frötschbach, ca. 12 km to the south-west of Seceda. The lower portions of the Buchenstein sections can be correlated on a bed-to-bed scale (Brack and Rieber, 1993, fig. 6). This is in agreement with the successions of magnetic reversals, conodonts and few macrofossils (Brack and Muttoni, 2000; Muttoni et al., 2004). The upper part of the Buchenstein Fm. at Bulla (Pufels) is linked to Seceda through distinct volcanocastic intervals (MPV, UPV), Daonella layers (Daonella taramellii) and a conspicuous megabreccia (corresponding to MB II at Seceda) below the lowermost mafic volcanic rocks at Bulla (Pufels).

Fig. 3. Seceda core: Quantitative distribution of POM types (I–IV), quantitative distribution of aquatic palynomorphs and ratio of marine to terrestrial organic matter.


The Caprile section of Van der Eem (1983) corresponds to the Belvedere (Colle S. Lucia) section of Brack and Muttoni (2000). Its ties to Seceda as shown in Muttoni et al. (2004) are based on physical stratigraphy (volcaniclastic intervals including the ash layers LPV, MPV, UPV, pelagic marker beds, and magnetic reversals). The correlation is supported by conodonts and few macrofossils including Daonella from the uppermost part of the Belvedere section (similar to forms in layers at Seceda corresponding to the 50 m or slightly younger core levels). Van der Eem's (1983) samples from Pieve and Moena are not considered here because their positions are insufficiently constrained. Nevertheless, in the Seceda core, samples Pie 2-11F and Pie 2-11A most likely correspond to the 80–90 m and 40–60 m intervals, respectively, and the position to the sample from Moena most likely falls in the 85– 95 m interval. The positions of the samples of Van der Eem (1983) projected onto the Seceda core are shown in Fig. 2. Our new correlation implies repositioning of samples compared to table 13 of Van der Eem (1983).

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inertinite is commonly associated with low representation, poor preservation or absence of palynomorphs. The distribution of the above mentioned categories reflects the preservation of the organic matter as well as its origin. The composition of the palynofacies assemblages is commonly used for sequence stratigraphic analysis (e.g. Tyson, 1995). In the present context it indicates the oxygenation status of the sediments in the relatively deep basin. Together with the POM types we summarize the abundance of palynomorphs of aquatic origin, which are in the present case essentially of marine origin (acritarchs, prasinophycean algae, and foraminiferal linings) as well as the ratio of the organic matter of marine and terrestrial origin (Fig. 3). The amount of POM type I and I/II essentially shows the intervals with the best preservation of the relatively fragile OM, corresponding to levels with reduced oxygenation. The light coloured pollen grains show no sign of thermal alteration of the organic matter indicating a maturation index of about 2 (Batten, 1982).

3. Method and material 4.1. Palynofacies results 33 samples of the Seceda core and 11 samples of the Val Gola– Margon sections were prepared with standard palynological procedure, using hydrofluoric acid (HF 35%) and hydrochloric acid (HCl, 75%). A short oxidation (1 min) with fumic nitric acid (NHO3) was then applied to remove pyrite and part of the organic matter. The residue was sieved with a 15 μm mesh sieve. For the present report 33 samples of the Seceda core have been studied for palynology and particulate organic matter (POM). For this purpose the finest-grained and apparently organic rich levels have been selected. The majority of the samples contain well-diversified palynomorph assemblages. Only one interval of the “Knollenkalke” (lower part of the section, 92.71–80.26 m) proved to be essentially barren of palynomorphs. In order to complete the palynological succession of this interval results from a stratigraphically corresponding outcrop section from the Val Gola–Margon are added to this study, including 10 fossiliferous samples. For the palynofacies and the palynological study a minimum of 250 particles or palynomorphs, respectively, were counted in the productive samples. 4. Palynofacies analysis of the Seceda core The palynofacies analysis of the Middle Triassic of the Seceda core is based on the study of 33 samples. The samples have been collected from the most silty and shaley levels. Carbonate rich beds have not been prepared. They would be dominated by strongly oxidized organic residue, e.g. opaque phytoclasts (see below). In Fig. 3 the quantitative distribution of the particulate organic matter (POM) is plotted as POM types (I to IV) (see below; for references see Tyson, 1995). – POM type I represents the least oxidation-resistant fraction. In the studied section POM type I consists of fluorescent amorphous organic matter (AOM) and algal remains attributed to Prasinophyceae and including a few specimens of Botryococcus. All constituents of POM type I are of aquatic origin. – POM type I/II: In contrast to the typical AOM, non-fluorescent AOM could be either of marine origin or represent degraded terrestrial origin matter. In the present context it is interpreted to be of marine origin. However, it is plotted separately from type I as type I/II. – POM type II comprises most of the palynomorphs (acritarchs and sporomorphs) as well as membranes and cuticles. – POM type III consists essentially of translucent phytoclasts, mostly woody particles; but it also includes chitinous remains such as scolecodonts and foraminiferal linings. – POM type IV includes strongly oxidized or charred OM such as charcoal, opaque phytoclasts and inertinite. It represents the residual part of the POM after exposure to strong oxidation. Abundance of

In most samples particulate organic matter of terrestrial origin clearly dominates. Considerable amounts of POM of marine origin (POM types I and II) are present near the base and in the upper part of the section (“Plattenkalke” and in parts of the “Knollenkalke” as well as in a few samples of the “Breccias”). 4.1.1. “Plattenkalke” (samples: 102.06–92.72 m) The palynofacies within this interval is characterised by the dominance of amorphous organic matter (AOM–POM types I and I/II). The composition of the assemblages in the five samples is rather homogenous. Fluorescent and non-fluorescent AOM occurs in about equal amounts. Palynomorphs, especially bisaccate pollen are relatively common. Trilete spores and acritarchs are regularly represented. Phytoclasts are relatively rare, compared to the rest of the section opaque particles are scarce. 4.1.2. “Knollenkalke” The lowermost part of the “Knollenkalke” (samples: 91.78–86.71 m) is marked by high representation of POM type I/II and by high numbers of membranes. The middle part of this unit shows high representation of POM types III and IV. Phytoclasts are relatively rare and except for a few spores palynomorphs are absent. The composition of the POM is quite homogeneous, except for the lowest sample, which contains an exceptionally high number of woody phytoclasts. In the middle part of the “Knollenkalke” (samples: 82.90–66.72 m) the POM associations show a quite heterogeneous composition. In most samples phytoclasts dominate; opaque material (structured and unstructured) is quite frequent. The most distinct feature of this assemblage is the rare occurrence of palynomorphs. Noteworthy is the exceptionally high number of membranes in the sample at 82.90 m and the relatively high amount of type I/II at 80.26 m. The interval between samples 69.26 and 62.50 m is marked by a conspicuous increase in the amount of POM type II with a corresponding decrease of type III. The uppermost sample of this interval also contains a considerable percentage of POM type I. 4.1.3. “Bänderkalke” From the top part of the “Knollenkalke” and in the “Bänderkalke” (samples: 49.20–46.22 m) we observe an increase in POM type II and high representation of type III. POM type IV reaches between 10 and 30%. Particles of marine origin are rare. 4.1.4. “Breccias” Within the “Breccias” unit palynofacies assemblages are quite heterogeneous. In the basal sample (42.53 m) POM types II, III and

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IV are about equally represented. The sample at 35.81 m is strongly dominated by type III. In the following two samples (34.86 and 31.90 m) we observed again an equal representation of POM types II, III and IV, but here associated with considerable amount of marine OM (type I and I/II). The POM at 28.92 m is completely dominated by membranes (type II), whereas the association in the sample at 25.46 m is almost identical to the one at 34.86 m. Another peak of POM type II can be noticed in the sample at 24.60 m. The remaining part of the section is characterised by high representation of POM type II together with relatively high percentages of types III and IV and low values for type I.

4.2. Interpretation of palynofacies The composition of the POM associations shows distinct variations in the depositional environment. The presence of fluorescent and nonfluorescent AOM in the “Plattenkalke” suggests dysoxic conditions. The consistent presence and the comparatively good preservation of palynomorphs, including marine forms, support this interpretation.

A marked change in the palynofacies can be observed at the transition between the “Plattenkalke” and the “Knollenkalke”. The regular occurrence of opaque material and the strong dominance of non-fluorescent AOM in the interval between samples 91.78 and 86.71 m reflect pronounced oxic conditions. The absence of pollen and palynomorphs of marine origin corroborate this interpretation. The non-fluorescent AOM observed in this part of the section probably represents severely degraded OM. In the middle part of the “Knollenkalke” (samples: 82.90 and 66.72 m) the varying composition of the POM associations probably corresponds to changing degrees of oxygenation. In most samples opaque material is abundant. Non-fluorescent AOM is common in one sample (80.26 m), probably representing degraded terrestrial OM. Palynomorphs are rare, and except for the uppermost sample marine forms are absent. The depositional environment can be interpreted as oxic, although in contrast to the interval below, some more fragile particles are preserved. Palynofacies assemblages from the upper part of the “Knollenkalke”, from the “Bänderkalke” and the lowermost part of the “Breccias” are characterised by the consistent frequency of palynomorphs, including some marine forms. Phytoclasts, namely woody particles, membranes,

Fig. 4. Seceda core: Quantitative distribution of sporomorph groups.


and cuticles are very common. One sample (62.50 m) containing common fluorescent AOM falls out of this pattern. In most samples sporomorphs are abundant and marine palynomorphs are consistently present. Opaque phytoclasts and non-fluorescent AOM, common in the lower part of the interval, decrease towards the top of the section. The changes in the palynofacies of the Seceda record go along with distinct lithological and sedimentological variations. The transition from dysoxic to well oxygenated bottom water conditions is reflected by the transition from laminated dark limestones of the “Plattenkalke” to the intensely bioturbated “Knollenkalke” (Maurer and Schlager, 2003). On a basin-wide scale, throughout the Dolomites, this change also correlates with a phase of drowning of carbonate platforms in the eastern Dolomites (Cernera, Clapsavon-Bivera; Brack et al., 2007), which could have modified the circulation patterns of bottom waters. The sample with higher AOM in the upper part of the “Knollenkalke” is from a laminated interval. Evidently, the bottom waters of the deep basin showed occasional recurrence of dysoxic conditions. The rapid increase in the number of turbidites with platform-derived debris as recorded in the “Bänderkalke” (Maurer et al., 2003) indicates the

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progradation of the approaching carbonate platforms (e.g. Geisler platform). This could possibly explain the increased supply of woody particles. 5. Palynological records from the Middle Triassic of the Southern Alps The Southern Alps are a classical area for the study palynological successions of Tethyan Triassic. Records include the classical studies of Van der Eem (1983) and Brugman (1986) but also newer work of Roghi (1997), Kustatscher and Roghi (2006), Kustatscher et al. (2006), Mietto et al. (2012), and Stockar et al. (2012). The new palynological results from the Seceda core constitute a well-calibrated stratigraphic succession covering the interval between the late Anisian (Illyrian) and the middle part of the late Ladinian (Longobardian). In the studied samples the preservation of the palynomorphs varies from mediocre to poor, showing distinct differences between the marine and the terrestrial forms. Marine palynomorphs (remains of Prasinophyceae and acritarchs) are

Fig. 5. Seceda core: Semiquantitative distribution of spores.

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generally quite well preserved, whereas most pollen grains show traces of severe degradation and are often strongly fragmented. Despite the limitations caused by the preservation the observed assemblages proved to be quite rich. Fig. 4 shows the quantitative distribution of the observed sporomorph groups. The semiquantitative distribution of 48 spore species in the Seceda core is plotted in Fig. 5 and the semiquantitative distribution of 80 pollen taxa is shown in Fig. 6. For the Val Gola–Margon outcrop section the semiquantitative distribution of sporomorphs is shown in Fig. 7. In some samples the preservation is too poor or the palynomorphs are too rare to allow for a quantitative assessment; however, the results of these samples are included in the distribution charts in order to provide a complete picture of the floral composition and to visualise the most distinct changes of the assemblages within the studied interval. For the present study we reviewed the zonation proposed by Van der Eem (1983) and subsequently modified by Brugman (1986). In the context of the presently precisely known stratigraphic succession of the Southern Alps (see above) we reassessed the stratigraphic position of the isolated outcrops that yielded the palynological data and the inferred zonation of Van der Eem (1983). The palynological succession resulting from the recalibration of these outcrops is plotted in Figs. 8 and 9, including the distribution of 43 spore- and 35 pollen taxa. 5.1. Sporomorphs For the following discussion the sporomorphs are grouped into the following categories: 5.1.1. Spores The semi-quantitative distribution of spores in the Seceda core is plotted in Fig. 5. The Val Gola–Margon record includes 26 spore species (Fig. 7). A detailed record of spores represented in Van der Eem's (1983) data is plotted in Fig. 8. 5.1.1.1. Aratrisporites group. For all the records the monolete lycopod spores of the genus Aratrisporites are plotted separately from the trilete spores (see below). The representatives of this group are generally rare. In the Seceda core they occur more regularly in the upper part of the studied interval (see Fig. 4). 5.1.1.2. Trilete spores. Smooth and ornamented spores are plotted as a single group. However, it has to be noted that, considering their botanical affinity, they represent a heterogeneous entity, including lycopods, ferns, and sphenopsids. Relatively common and consistently represented are the smooth forms such as Concavisporites, Deltoidospora, and Todisporites, which can be attributed to ferns. Calamospora, generally assigned to sphenopsids, is also consistently observed. Ornamented trilete spores appear as a highly diversified and heterogeneous group (see Figs. 5 and 8). Most of these forms can be attributed to ferns, but also include lycopod spores (e.g. Kraeuselisporites and Uvaesporites). Throughout the Seceda section trilete spores are rather uncommon. In contrast to that some samples of the Val Gola–Margon section contain considerable numbers of spores (Fig. 7). This is also true for Van der Eem's (1983) record (see Fig. 8). These differences are possibly due to palaeogeographic or taphonomic differences or to preservational bias. 5.1.2. Pollen The observed pollen grains are split into 9 groups following morphological criteria and if possible also considering botanical affinities. For the Seceda core the quantitative distribution of these groups is plotted in Fig. 4, and the ranges of the individual taxa in Fig. 6. Species ranges of the Val Gola–Margon section are shown in Fig. 7. The pollen record of Van der Eem (1983) is compiled in Fig. 9. Changes in the abundance of some of the listed groups are considered significant for the stratigraphic subdivision of the studied interval. The distribution charts are arranged according to the groups described below.

5.1.2.1. Alete bisaccate pollen. This heterogeneous group includes alete bisaccate pollen of various affinities (conifers and probably also pteridosperms), which are attributed to various genera. We also include indeterminate bisaccate pollen, which cannot be attributed to any specific group due to their preservation or unfavourably orientation in the slide. In many cases the state of preservation precludes also clear differentiation between the alete bisaccates and possible representatives of the Triadispora/Angustisulcites group (see below). Although, the indeterminate bisaccate pollen are very abundant throughout the sections, variations in their abundance reflect rather the state of preservation of the assemblages than being of stratigraphic significance. 5.1.2.2. Triadispora/Angustisulcites group. Beside Angustisulcites and Triadispora we consider the genus Kuglerina as part of this group, since it probably represents a monosaccate variant of the Triadispora group. In poorly preserved material the morphological features of the Triadispora/Angustisulcites group might be unrecognizable due to the orientation of the grains. Consequently, such specimens fall into the group of indeterminate bisaccate pollen. Representatives of the Triadispora/Angustisulcites group are abundant in most Middle Triassic spore–pollen assemblages. In the samples from the Seceda core we differentiated 13 taxa within this group, the distribution of some of them is considered of stratigraphic importance (e.g. Angustisulcites sp. A, Triadispora verrucata, and Kuglerina meieri). The group is very common throughout the Seceda section, becoming more abundant in its upper part. Van der Eem (1983) differentiated only three taxa within this group, which hampers the comparison and correlation of his data with record from the Seceda core. The pollen grains of the Triadispora/Angustisulcites group can be attributed to conifers (Balme, 1995) and are regarded as xerophytic elements (Visscher and Van der Zwan, 1981; Van der Eem, 1983; Kürschner and Herngreen, 2010). 5.1.2.3. Jugasporites/Illinites group. Bisaccate pollen grains with a monolete mark are attributed to this group. Representatives of Jugasporites are most common in the lowermost part of the Seceda section (zone TrS-A) and are also well presented in zone TrS-B. Representatives of Illinites occur throughout the section. In Van der Eem's (1983) record this group is represented by a single species (Illinites chitonoides). The quantitative distribution of this group changes considerably throughout the section and is for this reason considered of biostratigraphic relevance. 5.1.2.4. Taeniate bisaccate pollen. This group includes several genera (e.g. Lunatisporites, Striatoabieites, and Striatopodocarpites), all characterised by taeniae covering their central body. In poorly preserved material the differentiation of the genera is often unclear. In this study these forms are counted as indeterminate taeniate bisaccates. Taeniate bisaccate pollen are common and diverse throughout the studied sections, but are most abundant in the lower part of the Seceda core. The diversity of this group observed in the Seceda core (16 taxa) is much higher than in Van der Eem's (1983) record (7 taxa). This group includes some important markers such Strotersporites tozeri or the representatives of the genus Infernopollenites. Generally this group is associated with pteridosperms, and considered to represent xerophytic elements (Visscher and Van der Zwan, 1981; Van der Eem, 1983). 5.1.2.5. Ovalipollis group. Beside the genus Ovalipollis we also include Staurosaccites within this group. In poorly preserved material it might be difficult to differentiate the genera and individual taxa. Within the studied interval this group shows a significant increase, which is considered important for our biostratigraphic interpretation. In several zonation schemes Ovalipollis pseudoalatus is used as an important marker species (e.g. Van der Eem, 1983; Brugman, 1986; Brugman et al., 1994; Hochuli, 1998; Kürschner and Herngreen, 2010; Stockar et al.,

P.A. Hochuli et al. / Review of Palaeobotany and Palynology 218 (2015) 28–47 Fig. 6. Seceda core: Semi-quantitative distribution of the following pollen taxa, including the following groups: Alete bisaccate pollen, Triadispora/Angustisulcites, Jugasporites/Illinites group (*1), taeniate bisaccate pollen, Ovalipollis group (*2), Monosaccate pollen, Circumpolles group, Vitreisporites spp. (*3), and semiquantitative distribution of other gymnosperms (*4).

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Fig. 7. Val Gola–Margon outcrop: Semi-quantitative distribution of spores, including the following group: Aratrisporites (*1), trilete spores, alete bisaccate pollen (*2), Triadispora/ Angustisulcites (*3), Jugasporites/Illinites group (*4), taeniate bisaccate pollen (*5), Ovalipollis group (*6), monosaccate pollen (*7), Circumpolles group (*8), Vitreisporites spp. (*9), and semiquantitative distribution of other gymnosperms (*10).

Fig. 8. Semiquantitative distribution of spores according to recalibrated outcrop data from the Dolomites published by Van der Eem (1983).


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Fig. 9. Semiquantitative distribution of pollen taxa according to recalibrated outcrop data from the Dolomites published by Van der Eem (1983).

2012). The latter record obviously includes some erroneously determined specimens, including pollen grains with clearly separated sacci (e.g. Stockar et al., 2012, Fig. 7b). 5.1.2.6. Monosaccate pollen. This group includes various forms of monosaccate and also some polysaccate pollen grains, which are certainly of heterogeneous botanical origin. Undifferentiated forms are included as “Monosaccate pollen”. Some taxa of this group have restricted ranges and are of biostratigraphic significance (e.g. Stellapollenites thiergartii, Dyupelatum vicentinensis, Cannanoropollis spp., and Staropollenites spp.). The latter two genera are missing from Van der Eem's (1983) data set since they were only subsequently described by Brugman (1986). 5.1.2.7. Circumpolles group. Rare representatives of this group appear in the lower part of the sections considered. The first appearance of relatively rare specimens and the subsequent onset of continuous or

common representation of this group are considered of stratigraphic significance. They are common in zone TrS-C and above. The Circumpolles group is associated with the conifer family Cheirolepidiaceae and represents a distinct xerophytic element (Visscher and Van der Zwan, 1981; Van der Eem, 1983). 5.1.2.8. Vitreisporites group. Vitreisporites represents a bisaccate grain of pteridospermous origin (Balme, 1995). For this reason it is considered separately from other bisaccate pollen taxa. In the present material this long-ranging form is rather rare. 5.1.2.9. Miscellaneous gymnosperm pollen. Pollen grains of various morphologies and of heterogeneous botanical affinities are grouped under “Other gymnosperm pollen”. Quantitatively they are insignificant but some of them are important stratigraphic markers (e.g. Aulisporites astigmosus, Echinitosporites iliacoides, and possibly also Araucariacites); others are long ranging (e.g. Cycadopites and Ephedripites).

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5.2. Palynology of the Seceda section The distribution of some of the above mentioned groups shows distinct variations within the Seceda core. A clear decreasing trend can be seen in the distribution of the taeniate bisaccate pollen. They are abundant in the lowermost part of the “Plattenkalke” (R. reitzi zone) and are generally represented by less than 10% in the remaining part of the section. The distribution of the Jugasporites/Illinites group shows a similar, but less pronounced trend. Representatives of the Triadispora/Angustisulcites group show a general increase over studied interval. Ovalipollis and the representatives of the Circumpolles group are very rare in the basal part of the section; they become frequent or abundant in its upper part. Some species of the latter group appear within the studied interval. The samples prepared from the “Plattenkalke” of the Seceda core yielded relatively well preserved sporomorph assemblages. For the interval of the “Knollenkalke” 16 samples have been processed, of which only 8 from the upper part of this unit/member yielded reasonably preserved assemblages. Consequently there is a gap in the palynological record extending over an interval of about 12 m from 92.71 m up to 80.26 m including the entire N. secedensis zone and the lower part of the E. curionii zone. For our zonation scheme this gap is bridged by the palynological record from the Val Gola–Margon section, partly covering this interval (see below). Only two fossiliferous samples are available from the interval of the E. curionii zone; the other sample was barren. From the overlaying interval, transitional to the “P. gredleri” zone (72.0–64.5 m), three samples yielded well-diversified assemblages. The interval attributed to the “P. gredleri” zone (64.5–57.0 m) is covered by three fossiliferous samples. The two lower samples (63.71 and 62.50 m) are from laminated “Plattenkalk”-like sediments, which include in the Seceda outcrop the layers with Daonella moussoni. This interval also straddles a gap of 5–6 m of outcrop strata missing in the core and consisting of nodular limestone followed by distinct volcaniclastic layers including a level with “accretionary lapilli” and another short interval of laminated limestones. Sample 58.46 is from the transition of the latter to the uppermost part of the “Knollenkalke”. The top part of the “Knollenkalke” and the “Bänderkalke” (interval between 57.0 and 44.0 m) include the layers with Daonella taramellii and are transitional to the P. archelaus zone. From this interval, three fossiliferous samples have been studied. The interval above, attributed to the P. archelaus zone (44.0–25.0 m) and its transition to the F. regoledanus zone (25.0–17.0 m) yielded 10 samples with well-diversified assemblages. The correlation with the Bagolino succession indicates that the uppermost sample from the Seceda core (14.65 m) should correspond to the first layers with the ammonoid Frankites regoledanus in the lower Wengen Fm. at Bagolino and therefore likely belongs to the homonymous zone. 5.3. Palynology of the Val Gola–Margon section Ten samples from the Val Gola Limestone, corresponding to the N. secedensis ammonoid zone contain palynomorphs of terrestrial and marine origin with a clear upward increase of the marine forms. Higher up in the Val Gola–Margon succession, a rich palynological association has been reported from the Val Vela Limestone (Roghi, 1997). Based on the presence of ammonoids and conodonts this part of the succession has been correlated with the P. longobardicum zone (sensu Mietto and Manfrin, 1995). At Seceda this would probably correspond to a level in the interval between the “P. gredleri” and P. archelaus zones as indicated here. 5.4. Proposed zonation The zonation proposed for the interval between the late Anisian (Illyrian) and the late Ladinian (Longobardian) is based on the succession

of the Seceda core and the complementary outcrop section from Val Gola–Margon. We also use the newly calibrated events from the isolated outcrop sections studied by Van der Eem (1983). However, the latter record differs from our data in several respects. First of all a number of species, including some important stratigraphic markers, have been discovered since 1983, namely by the work of Brugman (1986). The comparison of our record with Van der Eem's (1983) data also shows that this author focused more on the determination and description of trilete spores than on the determination of pollen grains resulting in different numbers of taxa in the respective groups. Our use of the detailed taxonomic work on spores published by Van der Eem (1983) results in comparable numbers of spore taxa (43 taxa in Van der Eem's record versus 48 in our count). In contrast Van der Eem (1983) avoided differentiating a number of pollen groups (e.g. the Triadispora/Angustisulcites group or the taeniate bisaccate pollen), resulting in a pollen count of 35 taxa versus 80 taxa in our record. This different approach also limits the application of our zonation scheme to Van der Eem's (1983) data. For this reason it is impossible to tie the upper part of Van der Eem's Ladinian succession into our zonation scheme. Based on our data we propose 6 local palynological zones (TrS-A– TrS-F, TrS standing for Triassic and Southern Alps). They are based on variations in the distribution of the above mentioned groups as well as on ranges of individual taxa (see also Table 1). 5.4.1. Zone TrS-A Seceda core: 102.06–92.72 m (R. reitzi zone): 5 samples; Bulla section: 2 samples, Caprile section: 1 sample (Van der Eem, 1983, table I and II). Zone TrS-A falls within the R. reitzi ammonoid zone comprising the samples from the “Plattenkalke”. The assemblages are characterised by the common occurrence of taeniate bisaccate pollen and the representatives of the Jugasporites group as well as by a number of taxa, which are restricted to this interval, such as Cordaitina gunyalensis, Illinites kosankei, Jugasporites cf. convilminus, Lunatisporites transversundatus, Stellapollenites sp.1, and Strotersporites tozeri. Typical for this assemblage is also the relatively common occurrence of Voltziaceaesporites heteromorphus. In the Seceda core representatives of the Circumpolles group are sporadically observed. Duplicisporites tenebrosus and Partitisporites novimundanus are documented from the base of the Bulla and Caprile sections (Van der Eem, 1983). According to this record Ovalipollis pseudoalatus and Staurosaccites quadrifidus also appear within this interval (see Fig. 9). Thus the base of TrS-A is defined by the first appearance (FAD) of the following species: Duplicisporites tenebrosus, Ovalipollis pseudoalatus, Partitisporites novimundanus and Staurosaccites quadrifidus. Its top is marked by the disappearance (LAD) of Cordaitina gunyalensis, Illinites kosankei, Jugasporites cf. convilminus, Stellapollenites cf. thiergartii, and Strotersporites tozeri. 5.4.2. Zone TrS-B Val Gola–Margon (N. secedensis zone): 10 samples; Caprile section: 2 samples (Van der Eem, 1983, table II). Observed only in the Val Gola–Margon section (see above), zone TrS-B coincides with the N. secedensis ammonoid zone (sensu Brack and Rieber, 1993). The studied interval covers the transition between the Valle di Centa Marls and the Val Gola Limestone representing the uppermost part of the Anisian (Illyrian). Two samples from the Caprile section (Van der Eem, 1983) fall also within the N. secedensis ammonoid zone. Zone TrS-B can be differentiated from the underlying zone by the more common occurrence of representatives of the Ovalipollis group (Ovalipollis spp., Ovalipollis pseudoalatus) and the first occurrence of Camerosporites secatus (Caprile section, Van der Eem, 1983, table II). Other first occurrences include a number of spores such as the representatives of the Sellaspora group (Sellaspora spp. and Sellaspora rugoverrucata) as well as Foveosporites visscheri, Lycopodiacidites kokenii, and Porcellispora


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Table 1 Characteristics of the proposed palynological zones TrS-A–TrS-F. Note that all taxa listed as FAD in zone TrS-A represent first observations. Recalibrated records taken from Van der Eem (1983) are marked **. Stratigraphic interval

Zone

FADs

LADs and other specific features

Longobardian P. archelaus–F. regoledanus zone

TrS-F

Increase in diversity and abundance of the Circumpolles group

Fassanian–Longobardian “P. gredleri”–P. archelaus zone

TrS-E

Fassanian E. curionii–? “P. gredleri” zone

TrS-D

Fassanian E. curionii zone

TrS-C

Illyrian N. secedensis zone

TrS-B

Illyrian R. reitzi zone

TrS-A

Aulisporites astigmosus (sporadic) Costatisulcites ovatus Doubingerispora filamentosa (sporadic) Enzonalasporites vigens Patinasporites spp. (sporadic) Reticulatisporites dolomiticus Anapiculatisporites spiniger** Annulispora spp. (sporadic) Araucariacites spp. Convolutispora sp. B** Corbulispora sp. A and sp. B** Infernopollenites rieberi (sporadic) Lueckisporites cf. singhii Bianulisporites badius (sporadic) ** Circumstriatites spp. ** Duplicisporites verrucosus Echinitosporites iliacoides ** Enzonalasporites spp. Heliosaccus dimorphus ** Infernopollenites parvus ** Podosporites amicus (sporadic) Triadispora verrucata Bocciaspora blackstonensis ** Duplicisporites granulatus Kyrtomisporites ervii ** Sellaspora rugoverrucata ** Camerosporites secatus ** Foveosporites visscheri Lycopodiacidites kokenii Ovalisporites pseudoalatus (common) ** Paracirculina spp. Porcellispora longdonensis Sellaspora spp. and S. foveorugulata Uvaesporites sp. A** Cannanoropollis scheuringii Dyupetalum vicentinense Kuglerina meieri Staropollenites antonescui Stellapollenites thiergartii Concentricisporites plurianulatus ** Duplicisporites tenebrosus ** Ovalipollis pseudoalatus ** (rare) Palaeospongisporis europaeus** Partitisporites novimundanus** Staurosaccites quadrifidus ** (sporadic)

longdonensis. A single record of Jerseyiaspora punctispinosa occurs within the sample at 4.50 m. and The highest record (LAD) of Staropollenites spp. has also been observed within this interval. Taeniate bisaccate pollen grains are also relatively common. Thus the base of zone TrS-B is defined by the first appearance (FAD) of Camerosporites secatus, Foveosporites visscheri, Lycopodiacidites kokenii, Sellaspora spp. and S. rugoverrucata. Its top is marked by the LAD of the following species: Jugasporites conmilvinus, Staropollenites antonescui and Stellapollenites thiergartii. The samples studied by Van der Eem (1983) from the interval now attributed to the N. secedensis zone cannot unambiguously attributed to zone TrS-B since they lack records of the marker taxa like Stellapollenites thiergartii and Staropollenites antonescui. Considering palynological evidence alone they fall within the interval of the zone TrS-B to TrS-C. 5.4.3. Zone TrS-C Seceda core: 80.26–73.27 m: 2 samples; Bulla section: 1 sample; Caprile section: 2 samples (Van der Eem, 1983, tables II and II). Two productive samples of the Seceda core assigned to this zone fall into the E. curionii zone. Thus zone TrS-C represents the lowest part of the Ladinian (Fassanian). It is characterised by the consistent and frequent occurrence of the Ovalipollis group. Noteworthy is also the FAD

Cannanoropollis scheuringii (sporadic) Cannanoropollis spp. (sporadic) Dyupetalum vicentinense Jugasporites conmilvinus (sporadic)

Stellapollenites thiergartii, Staropollenites spp. Staropollenites antonescui Jugasporites conmilvinus (consistent)

Strotersporites tozeri Stellapollenites sp. 1 Taeniate bisaccates (common) Jugasporites/Illinites group (common)

of Duplicisporites granulatus. In the Bulla and Caprile section (Van der Eem, 1983) this interval includes the first appearance of a number of trilete spores such as Bocciaspora blackstonensis, Kyrtomisporites ervii, and Sellaspora rugoverrucata (see Fig. 8). The base of zone TrS-C is defined by the appearance (FAD) of Bocciaspora blackstonensis, Duplicisporites granulatus, Kyrtomisporites ervii, and Sellaspora rugoverrucata. There are no LADs marking the top of this zone; it can be defined by the absence of the species appearing in the overlying zone TrS-C (see below). 5.4.4. Zone TrS-D Seceda core: 69.26–62.50 m: 5 samples; Caprile section: 3 samples (Van der Eem, 1983, table II). In the Seceda core the lower three samples of the interval of zone TrSD fall in the interval transitional between the E. curionii and the “P. gredleri” zones, whereas the upper two are from layers ascribed to the “P. gredleri” ammonoid zone. Compared to the underlying palynological zone the representatives of Ovalipollis and of the Circumpolles groups are more common. First appearances (FADs) include representatives of the Circumpolles group such as Duplicisporites verrucosus and Enzonalasporites spp. and Triadispora verrucata. Last appearances (LADs) include Cannanoropollis (Cannanoropollis spp. and Cannanoropollis scheuringii) and Dyupetalum vicentinense together with the last

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observations of rare forms like Strotersporites spp. and Tumoripollenites spp. The sample at 58.46 m from the uppermost “Knollenkalke” contains a poorly preserved, non-diagnostic assemblage. Following the record of Van der Eem (1983) we consider the FAD of Echinitosporites iliacoides an important marker of this zone. Heliosaccus dimorphus, also commonly mentioned as an index species has not been observed in our material. According to Van der Eem (1983) it should also appear within this interval. However, both species are rare in the records of the Southern Alps. The base of zone TrS-C is marked by the appearance (FAD) of the following species: Duplicisporites verrucosus, Echinitosporites iliacoides, Enzonalasporites spp., and Triadispora verrucata. Its top is characterised by the disappearance (LAD) of Cannanoropollis (Cannanoropollis spp. and Cannanoropollis scheuringii), Dyupetalum vicentinense, and Strotersporites spp.

5.4.5. Zone TrS-E Seceda core: 55.33–42.53 m: 4 samples. The main part of the interval covered by zone TrS-E is transitional between the “P. gredleri” zone and the P. archelaus zone reaching with its upper part into the latter zone. Lithologically it comprises the topmost “Knollenkalke”, the “Bänderkalke” and the base of the “Breccias”. Assemblages of zone TrS-E can be differentiated from the underlying and overlying zones by a few diagnostic events such as the FADs of Annulispora spp., Araucariacites spp., Infernopollenites rieberi, and Lueckisporites cf. singhii. In Van der Eem (1983) the first appearances of Anapiculatisporites spiniger, Convolutispora sp. B, as well as Corbulispora sp. A and Corbulispora sp. B fall within this interval. Two samples from the Caprile (Cap U) and the Bulla (Pufels) section (Puf AY) fall within the “P. gredleri” zone. Lacking the characteristic features of zone TrS-E the composition of these assemblages indicates a range from zone TrS-D to TrS-E. A similar assemblage has been reported from one sample of the Aschkler section (Ask A) (see Figs. 8 and 9). The base of zone TrS-E is defined by the first appearance (FAD) of Anapiculatisporites spiniger, Annulispora spp., Araucariacites spp., Convolutispora sp. A and sp. B, Corbulispora sp. B, Infernopollenites rieberi, and Lueckisporites cf. singhii. There is no top occurrence to mark the top of this zone. Thus TrS-E covers the interval between the FADs of the above mentioned species and the FADs defining TrS-F.

5.4.6. Zone TrS-F Seceda core: 35.81–14.86: 10 samples. Zone TrS-F is confined to the “Breccias” unit and falls within the P. archelaus ammonoid zone and its transition to the F. regoledanus zone. Additionally, several species appear first in this part of the section, such as the rare forms Aulisporites astigmosus, Costatisulcites ovatus, Doubingerispora filamentosa, and Patinasporites spp. The species Enzonalasporites vigens and Reticulatisporites dolomiticus are regularly observed within zone TrS-E. In the compilation of Brugman (1986) the first mentioned species appears in the upper part of the P. archelaus zone (lower part of the secatus–vigens phase) occurring together with the marker E. iliacoides. Thus the base of zone TrS-F is defined by the first appearance (FAD) of Aulisporites astigmosus, Costatisulcites ovatus, Doubingerispora filamentosa, Enzonalasporites vigens, and Patinasporites spp. Representing the top of the studied section the top of zone Tr-S-F remains undefined. In the record of Van der Eem (1983) Enzonalasporites vigens is not mentioned from this interval preventing the recognition of zone TrS-F in his record. Due to the lack of the corresponding marker species the upper part of Van der Eem's (1983 tables II, V, VII) record (Bulla section: 4 samples, Aschkler section: 4 samples, Pana section: 4 sample) corresponds to a range from zone TrS-E to TrS-F.

6. Discussion 6.1. Comparison with palynological zones (phases) of the Tethyan realm So far the palynological successions of Van der Eem (1983) and Brugman (1986) represented the most complete zonation scheme for the western Tethys. However, both schemes were based on sections, which had been dated by various authors and with varying confidence. The lithological logs provided by Van der Eem (1983) allow for correlation of the logged intervals into the precisely established lithological scheme of the Middle Triassic (Late Anisian and Ladinian) of the Southern Alps. The integration of the lithological intervals studied by Van der Eem shows that they cover the entire interval between the late Anisian and the top of the Ladinian. However, the stratigraphic position of the palynological phases determined in the various sections covering this interval varies considerably. Consequently the correct positioning of the studied intervals changes the palynological succession and the ranges of the marker species. Thus the lower part of the Caprile section, including the samples Cap D, G and H, which were assigned to the plurianulatus–secatus phase and originally thought to represent the lower part of the Longobardian, falls within the interval between top part of the Anisian (Illyrian) and the lower part of the Fassanian. Consequently the ranges of the sporomorphs characterising this phase (e.g. Camerosporites secatus and Duplicisporites granulatus) change correspondingly. The position of the intervals studied by Van der Eem (1983) and the corresponding palynological phases are shown in Fig. 10. Essentially based on the co-occurrence of the marker species Cannanoropollis scheuringii, Dyupetalum vicentinense, and Stellapollenites thiergartii, zones TrS-A and TrS-B can be compared with the “vicentinense–scheuringii phase” of Brugman (1986). According to this author this phase is defined by the highest regular (frequent) occurrence of the two first mentioned forms as well as by the first appearance (FAD) of C. scheuringii. In the Bulla (Pufels) section (north-western Dolomites) the highest occurrences of S. thiergartii and D. vicentinensis have been found up to the top part of the Illyrian (sample AE of Brugman, 1986). Following Krystyn (1983) Brugman (1986) correlated the “vicentinense–scheuringii phase” with the Parakellnerites sp. ammonoid zone, which can be considered as largely corresponding to the R. reitzi zone sensu Brack and Rieber (1993); hence the ranges of the above mentioned taxa provide consistent biostratigraphic events and confirm a late Anisian (Illyrian) age for the zones TrS-A and TrS-B. The Bulla (Pufels) section is situated between Frötschbach and Seceda and the Buchenstein successions corresponding to the “Plattenkalke” and the lower “Knollenkalke” are identical in the three sections (see fig. 6, in Brack and Rieber, 1993; Muttoni et al., 2004). Van der Eem's (1983) samples AE and AH from the “Plattenkalke” at Bulla (Pufels) therefore entirely overlap with the Seceda samples defining zone TrS-A. Within zone TrS-B the overlap of the ranges of Ovalipollis spp. (Staurosaccites/Ovalipollis spp.) and representatives of the Circumpolles group (Duplicisporites tenebrosus and Paracirculina spp. belonging to the Partitisporites novimundanus morphon of Brugman, 1986) on one hand and Stellapollenites thiergartii on the other might suggest a correlation with the lower part of the “plurianulatus–novimundanus phase” of Brugman (1986). According to this author S. thiergartii disappears together with Dyupetalum vicentinense and Strotersporites tozeri within this phase. In our material the latter species has been observed only in zone TrS-A, whereas S. thiergartii ranges up into zone TrS-B and Dyupetalum vicentinensis into zone TrS-D. Another difference to the record of Brugman (1986) appears in the first record of Sellaspora spp. In our material this group has been observed as an isolated occurrence in zone TrS-B, whereas Brugman (1986) reported it from the “plurianulatus–secatus phase” (see below). Interestingly Van der Eem's (1983) samples Cap D and Cap G of the Caprile section ascribed to the “plurianulatus–secatus phase” are from layers corresponding to the N. secedensis ammonoid zone and should therefore largely overlap


43

Fig. 10. Lithological section of the Seceda core with chronostratigraphy, ammonoid zones, the proposed palynological zones and the correlated positions of the samples and sections studied by Van der Eem (1983) with the corresponding palynological phases.

with our zone TrS-B. First isolated occurrences of Ovalipollis spp. have also been reported from palynologically poorly diversified samples of the N. secedensis zone at Monte San Giorgio (Stockar et al., 2012). Based on the FAD of Duplicisporites granulatus zone TrS-C can also be compared with the “plurianulatus–novimundanus phase” of Brugman (1986). The LADs of several species (e.g. Dyupetalum vicentinensis, Stellapollenites thiergartii, and Strotersporites tozeri see above) suggested that this phase could have been subdivided. Our results indicate that zone TrS-B is comparable with the lower part of the “plurianulatus– novimundanus phase” whereas zone TrS-C seems to match with its upper part. According to Brugman (1986) the “plurianulatus–

novimundanus phase” is coeval with the Nevadites sp. ammonoid zone, which should be largely equivalent with the N. secedensis ammonoid zone (Brack and Rieber, 1993; Brack et al., 1996). Thus the correlation of zone TrS-C with the “plurianulatus–novimundanus phase” contradicts the age assignment of Brugman (1986). Originally Van der Eem's (1983) “plurianulatus–novimundanus phase” was based on the sample Puf AH from the “Plattenkalke” (Brugman, 1986, p. 51), which largely corresponds to zone TrS-A. In the Ladinian part of the section the repositioned succession of the palynological phases of Van der Eem (1983) and Brugman (1986) shows the overlap of the plurianulatus–novimundanus phase the with

44


plurianulatus–secatus phase, and the latter overlaps with secatus– dimorphus phase (see Fig. 10). For this reason we do not attempt to compare these phases with the proposed zones. The assemblages (I–III) described by Stockar et al. (2012) from the Monte San Giorgio area (S. Switzerland) are difficult to assess since they are based on the occurrence on too few selected species, including long-ranging forms. Based on the co-occurrence of Cannanoropollis scheuringii and Illinites kosankei zone TrS-A can be compared with local palynozone TrSM-B of Dal Corso et al. (2014). 6.2. Correlation with the Germanic Basin Based on numerous published records (e.g. Heunisch, 1999; Orłowska-Zwolinska, 1977, 1984, 1985, 1988; Reitz, 1985) and some unpublished reports, Kürschner and Herngreen (2010) compiled a palynological zonation for the Triassic of the Germanic Basin and suggested a correlation with the zonation scheme of the Southern Alps (Brugman, 1986). For the Anisian of the Germanic Basin the authors proposed one zone — the S. thiergartii zone, which they subdivided into three subzones, in ascending order the Platysaccus leschikii, Protodiploxipinus doubingeri, and the Institisporites subzones. The Institisporites subzone, interpreted to correspond to the upper part of the Anisian (Illyrian) is marked at its base by the FAD of Institisporites sp. and Podosporites amicus and at its top by the LADs of S. thiergartii, Tsugaepollenites oriens, and D. vicentinensis. Within this zone the authors indicate the FADs of Camerozonosporites rudis and Kuglerina meieri, the latter being question-marked (Kürschner and Herngreen, 2010, Fig. 3). For the Ladinian, Kürschner and Herngreen (2010) recognise a single zone — the Heliosaccus dimorphus zone; its base is marked by the FAD of Heliosaccus dimorphus. One level in its lower part is marked by the FAD of several species such as Duplicisporites granulatus, Echinitosporites iliacoides, Ovalipollis pseudoalatus, Partitisporites novimundanus, and Staurosaccites quadrifidus. It is interpreted to correspond to the middle part of the Fassanian. Two sets of events have been listed for the upper part of the Ladinian, the first one concerns the FAD of Aulisporites astigmosus and Infernopollenites spp., interpreted to be located in the middle part of the Longobardian, and second one with the FAD of Enzonalasporites vigens, as well as the common appearance of the Circumpolles Duplicisporites spp. and Partitisporites spp. falls in the upper part of the Fassanian. The lower part of the Carnian defined as Triadispora verrucata subzone is marked by the FAD of the eponymous together with Camerosporites secatus, Patinasporites densus, and Vallasporites ignacii. The comparison of the succession compiled by Kürschner and Herngreen (2010) with the results of the present study shows considerable differences between the Germanic and the Tethyan realm that hamper reliable correlations. Considering the fact that the ages assigned to the Germanic succession are essentially inferred without independent age control, some important events seem to occur approximately in the same stratigraphic interval. The LAD of St. thiergartii marking the top of the Anisian in our material is also used to delimit this stage in the Germanic realm. It has to be pointed out that in the latter area this species is extremely rare in the upper part of its range. The other markers used to indicate this boundary – Dyupetalum vicentinensis and Tsugaepollenites oriens – seem to be less age-diagnostic, the first one occurs only sporadically in the lower part of the Ladinian in our material, whereas the second one has not been found at all. Heliosaccus dimorphus marking the Ladinian H. dimorphus zone in the Germanic realm was used as index species for the secatus dimorphus phase of Van der Eem (1983) to which a Longobardian age was attributed. The recalibration of Van der Eem's succession shows a first appearance of this species in the “P. gredleri” zone. However, this species is too rare to allow for reliable correlations. The widely used marker Echinitosporites iliacoides appears in our zone TrS-D in the upper part of the E. curionii zone. This level seems to concur with the position of its FAD in the Germanic realm (see also Brack et al., 1999) where its

FAD is also associated with the FAD of Duplicisporites granulatus. Assuming a similar range in the two areas the latter authors suggested that the base of the Lettenkeuper in the Germanic basin could fall within the “P. gredleri” zone or, according to our new results, even at a somewhat deeper level. Apparently similar ranges can be noticed for Aulisporites astigmosus and Enzonalasporites vigens, which appear in both areas within the Longobardian (TrS-F and upper part of the Heliosaccus dimorphus zone in Kürschner and Herngreen, 2010). However, for several species remarkable differences in their ranges can be inferred from our results. The FAD of Ovalipollis pseudoalatus and Staurosaccites quadrifidus, regarded as distinct event, occurs in our material in the late Anisian and appears in the Germanic realm in the middle part of the Fassanian. An even greater difference in species range can be shown for Camerosporites secatus. According to our results this species regularly occurs throughout the Ladinian, whereas in the Germanic realm its FAD is supposed to mark the base of the Carnian (Kürschner and Herngreen, 2010). 7. Conclusions In this paper we present the results of the study of the particulate organic matter (palynofacies) and the palynological record from a continuous core section at Seceda complemented with outcrop samples from Val Gola. Palynofacies reveals changing depositional environments. With its content of fluorescent AOM the palynofacies of the “Plattenkalke” member in the Buchenstein Fm. at Seceda suggests dysoxic conditions. The change in palynofacies between the “Plattenkalke” and the “Knollenkalke” corresponds to a marked change in a deepening pelagic depositional environment from dysoxic to well oxygenated conditions. Brack et al. (2007) observed that this change coincides with the drowning of carbonate platforms in the central Dolomites and further east (Cernera, Monte Bivera–Clapsavon) possibly leading to the onset of bottom water circulation in the Buchenstein basins of the western Dolomites. The succession of palynofacies from the “Knollenkalke” to the “Breccias” suggests a depositional environment with a slight reduction of the oxic conditions. This change is best represented in the increasing abundance of the palynomorphs towards the top of the core. The POM of the “Breccias” interval also indicates slightly reduced oxic conditions. Establishment of episodic dysoxic conditions is suggested by the composition of the OM in the sample at 62.50 m containing considerable amounts of fluorescent AOM. This may point to bottom waters remaining close to an oxic/dysoxic boundary in a basin whose floor was ultimately more than 700 m deep. Based on the combination of the palynological records from the Buchenstein Fm. at Seceda (core) and from the outcrop section at Val Gola–Margon, we propose a new palynological framework for the interval between the late Anisian (R. reitzi zone) and the late Ladinian (P. archelaus zone). The now precisely known stratigraphic succession of the Southern Alps including lithostratigraphy, biostratigraphy, and magnetostratigraphy allows us to integrate the data of the classical palynological studies of Van der Eem (1983) and Brugman (1986), recalibrating the stratigraphic position of the outcrops used by these authors. This leads to a considerable change in the succession of the palynological phases defined by Van der Eem (1983) and consequently also to some considerable changes in species ranges. Based on the stratigraphic range of a number of species as well as on the quantitative distribution of the main floral elements, the succession is subdivided into six palynological zones (TrS-A–TrS-F). The Seceda section represents the principal auxiliary section to the GSSP of the Ladinian stage and the studied succession is well tied to magnetostratigraphy, radiometric age data and biostratigraphic schemes of a low latitude marine realm (Muttoni et al., 2004; Brack et al., 2005, 2007). The distributions of pollen and spores reflect the evolution of terrestrial floras during an interval of around four million years. Within the Anisian/Ladinian interval a major floral turnover occurs in the Buchenstein Fm., near the boundary between “Plattenkalke” and


“Knollenkalke”. In the late Anisian of the Seceda core pteridosperms (taeniate bisaccate pollen) dominate, whereas in the Ladinian there is a clear domination of conifers, including the Ovalipollis group as well as the representatives of the Circumpolles groups, which becomes one of the major elements in the upper part of the studied section. This turnover probably represents a climatic signal, which has the potential for long range correlations. The comparison of the palynological succession of the Tethyan realm with those of the Germanic realm suggests that during the Anisian the floral assemblages were quite similar with closely comparable ranges of the main marker species (e.g. Stellapollenites thiergartii). Ladinian assemblages seem to show more pronounced differences in the composition of the assemblages including important differences in the ranges of the marker species (e.g. Camerosporites secatus, Ovalipollis pseudoalatus).

45

Discisporites psilatus De Jersey 1964 Doubingerispora filamentosa Scheuring 1978 Duplicisporites granulatus Leschik, in Kräusel and Leschik 1956 Duplicisporites tenebrosus (Scheuring 1970) Scheuring 1978 Duplicisporites verrucosus Leschik, in Kräusel and Leschik 1956 Dyupetalum vicentinense Brugman 1983 Dyupetalum cf. vicentinense Brugman 1983 Echinitosporites iliacoides Schulz and Krutzsch 1961 Enzonalasporites spp. Enzonalasporites vigens Leschik, in Kräusel and Leschik 1956 Ephedripites spp. Eucommidites spp. Foveosporites spp. Foveosporites visscheri Van Erve 1977

Annotated species list

Gleicheniidites spp. Gordonispora fossulata (Balme 1970) Van der Eem 1983

Alisporites grauvogeli Klaus 1964

Indeterminate bisaccates

Alisporites spp.

Indeterminate taeniate bisaccates

Angustisulcites gorpii Visscher 1966

Illinites chitonoides Klaus 1964

Angustisulcites klausii Freudenthal 1964

Infernopollenites rieberi Scheuring 1978

Angustisulcites sp. A Brugman 1986

Infernopollenites parvus Scheuring 1970

Angustisulcites spp.

Infernopollenites spp.

Annulispora spp.

Jerseyiaspora punctispinosa Kar, Kieser and Jain 1973 Jugasporites conmilvinus Klaus 1964

Aratrisporites fimbriatus (Klaus 1960) Mädler 1964 Aratrisporites reticulatus Brugman 1986

Jugasporites cf. conmilvinus Klaus 1964

Aratrisporites saturni (Thiergart 1949) Mädler 1964

Jugasporites aff. conmilvinus Klaus 1964

Aratrisporites scabratus Klaus 1960

Jugasporites spp.

Aratrisporites spp.

Klausipollenites schaubergeri (Potonié and Klaus 1954) Jansonius 1962

Aratrisporites tenuispinosus Playford 1965

Kraeuselisporites spp.

Araucariacites spp.

Kuglerina meierii Scheuring 1978

Aulisporites astigmosus (Leschik, in Kräusel and Leschik 1956) Klaus 1960

Kyrtomisporis ervii Van der Eem 1983 Kyrtomisporis spp.

Baculatisporites spp.

Lueckisporites cf. singhii Balme 1970

Biretisporites spp.

Lunatisporites acutus Leschik, in Kräusel and Leschik 1956

Brachysaccus spp.

Lunatisporites noviaulensis (Leschik, in Kräusel and Leschik 1956) Scheuring 1970 Lunatisporites pellucidus (Goubin 1965) De Jersey 1971

Calamospora spp. Camerosporites pseudoverrucatus Scheuring 1970 Camerosporites secatus Leschik, in Kräusel and Leschik 1956 Camarozonosporites spp. Cannanoropollis scheuringii Brugman 1986 Cannanoropollis spp.

Lunatisporites spp. Lunatisporites transversundatus (Jansonius 1962) Dunay and Fisher 1979

Chordasporites spp.

Lycopodiacidites kokenii Van der Eem 1983 Monosaccate pollen Neevesisporites vallatus De Jersey and Patten 1964

Cingutriletes spp.

Ovalipollis cf. cultus Scheuring 1970

Concavisporites spp. Converrucosisporites spp.

Ovalipollis spp.

Convolutispora jugosa Smith and Butterworth 1967

Palaeospongisporis europaeus Schulz 1965

Convolutispora cf. jugosa Smith and Butterworth 1967

Paracirculina spp.

Convolutispora sp. A Van der Eem 1983

Partitisporites spp. Patinasporites spp.

Chordasporites singulichorda Klaus 1960

Convolutispora sp. B Van der Eem 1983 Convolutispora spp. Cordaitina gunyalensis (Pant and Srivastava 1964) Balme 1970

Ovalipollis pseudoalatus (Thiergart 1949) Schuurman 1976

Perotriletes spp. Platysaccus spp.

Cordaitina spp. Costatisulcites ovatus Scheuring 1978

Podosporites amicus Scheuring 1970

Cycadopites spp.

Protodiploxypinus spp.

Cyclogranisporites spp.

Protodiploxypinus sittleri (Klaus 1964) Scheuring 1978

Deltoidospora spp.

Protohaploxypinus spp. Punctatisporites punctatus (Malyavkina 1956) Varyukhina 1971

Densoisporites spp.

Porcellispora longdonensis (Clarke 1965) Scheuring 1970

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Punctatisporites spp. Reticulatisporites dolomiticus Blendinger 1988 Reticulatisporites spp. Retusotriletes mesozoicus Klaus 1960 Sellaspora foveorugulata Van der Eem 1983 Sellaspora rugoverrucata Van der Eem 1983 Sellaspora spp. Staropollenites antonescui Brugman 1986 Staropollenites spp. Staurosaccites quadrifidus Dolby, in Dolby and Balme 1976 Staurosaccites spp. Stellapollenites thiergartii (Mädler 1964) Clement-Westerhof et al., 1974 Stellapollenites sp.1, small form, see St. cf. thiergartii (Mädler 1964) Clement-Westerhof et al., 1974, sensu Sommaruga et al., 1997 Striatoabieites aytugii Visscher 1966 Striatoabieites balmei Klaus 1964 Striatoabieites cf. balmei Klaus 1964 Striatopodocarpites spp. Strotersporites spp. Strotersporites tozeri Brugman 1986 Sulcatisporites spp. Tigrisporites playfordi De Jersey and Hamilton 1967 Todisporites major Couper 1958 Todisporites spp. Trachysporites spp. Triadispora aurea Scheuring 1970 Triadispora boelchii Scheuring 1970 Triadispora crassa Klaus 1964 Triadispora epigona Klaus 1964 Triadispora humilis Scheuring 1970 Triadispora modesta Scheuring 1970 Triadispora obscura Scheuring 1970 Triadispora aff. obscura Scheuring 1970 Triadispora plicata Klaus 1964 Triadispora spp. Triadispora stabilis Scheuring 1970 Triadispora staplinii (Jansonius 1962) Klaus 1964 Triadispora suspecta Scheuring 1970 Triadispora verrucata (Schulz 1966) Scheuring 1970 Trilete spores indet. Uvaesporites gadensis Praehauser-Enzenberg 1970 Uvaesporites spp. Verrucosisporites morulae Klaus 1960 Verrucosisporites cf. reinhardtii Visscher 1966 Verrucosisporites spp. Votziaceaesporites heteromorphus Klaus 1964 Votziaceaesporites spp. Vitreisporites pallidus (Reissinger 1950) Nilsson 1958 References Arthaber, G., 1916. Die Fossilführung der anisischen Stufe in der Umgebung von Trient. K.Kg. Geol. Reichsanst. Verh. Jb. 65, 239–260. Balme, B.E., 1995. Fossil in situ spores and pollen grains: an annotated catalogue. Rev. Palaeobot. Palynol. 87, 81–323. Batten, D.J., 1982. Palynofacies, palaeoenvironments and petroleum. J. Micropalaeontol. 1, 107–114. Bittner, A., 1892. Was ist norisch? K.-Kg. Geol. Reichsanst. Verh. Jb. 42, 387–396. Brack, P., Muttoni, G., 2000. High-resolution magnetostratigraphic and lithostratigraphic correlations in the Middle Triassic pelagic carbonates from the Dolomites (northern Italy). Palaeogeogr. Palaeoclimatol. Palaeoecol. 161, 361–380.

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