AN INTEGRATED STUDY ON LATE CISURALIAN (EARLY PERMIAN)

Scuola di Dottorato in Scienze della Terra,
Dipartimento di Geoscienze, Università degli Studi di Padova – A.A. 2014-2015
AN INTEGRATED STUDY ON LATE CISURALIAN (EARLY PERMIAN)
PALAEOENVIRONMENTS AND PALAEOCLIMATE OF SOUTHERN ALPS
Ph.D. candidate: GIUSEPPA FORTE, I course
Tutor: Prof. NEREO PRETO
Co-Tutors: Dr. GUIDO ROGHI
Dr. EVELYN KUSTATSCHER
Cycle: XXX
Abstract
A major transition of the Earth flora occurred during the Permian. The flora changed from hygrophytic, ever-wet, coalforming to xerophytic, seasonally dry. The mechanisms behind this revolution of the ecosystems are still poorly understood.
The aim of this PhD project is to provide palaeoenvironmental and palaeoclimate reconstructions of the lower Permian basins
of the Southern Alps through the study of palaeofloras, palaeopalynofloras and geochemistry of the organic matter. During
this first year we investigated the Tregiovo Basin (Trento province), studying its macroflora and collecting paleopalynological
and geochemical samples. The first preliminary results on the taxonomical analysis of plant remains of the Tregiovo flora
revealed surprising data, allowing to extend backward the first occurrence of some taxa, known before only from the upper
Permian, to describe a new taxon previously unreported in the literature and thus to enrich our knowledge about the evolution
of conifers.
Full Report
Introduction
During the Permian, the Earth was interested by a series of big changes. It went through a deglaciation,
after the ice age that interested mostly the Southern hemisphere during the Carboniferous. The last phases
of the Hercynian orogeny fragmented the palaeoequtorial areas of the Pangea and an increasing aridity
interested the palaeoequatorial regions (DiMichele et al., 2008). In this scenario, one of the most
important transition periods of the terrestrial ecosystems took place. In fact, during the PennsylvanianPermian the vegetation of the palaeotropics changed from hygrophytic, ever-wet, coal-forming to
xerophytic and seasonally dry (e.g. DiMichele et al., 2001, 2014). This replacement of hygrophytic by
xerophytic communities was globally asynchronous, proceeding from west to east and having its origin in
western North America (Knoll, 1984; DiMichele et al., 2001). Representatives of seasonally dry floras
include members of the gymnosperms such as conifers, cycads and peltasperms. However, trend and
dynamics of this floral replacement are still poorly understood, due to the fact that palaeotropical floras of
early-middle Permian age are rare. So far, mixed floras have been reported only from the lower Permian
of the western part of equatorial Pangea (e.g. North America: DiMichele et al., 2001, 2002; Looy, 2007;
Looy et al., 2014). The discovery of a new paleoflora from the lower Permian of Tregiovo (“Le Fraine
section”, Trento province) gives new insight on the Permian floristic transition (Marchetti et al., 2015).
The study of early Permian palaeofloras and paleopalynofloras of the Southern Alps may allow to
reconstruct the early Permian terrestrial ecosystems, and geochemical investigations may provide further
insights on local palaeoclimate. Moreover, the Permian represents a key interval of time to understand the
dynamics of evolution and diversification of conifers, one of the most important plant groups of the
Permian ecosystems, that became dominant during the Mesozoic. This also may contribute to better
understand the mechanisms behind the Permian floristic transition in Pangean equatorial ecosystems.
Materials and Methods
This research project implies the study of palaeofloras (plant remains and palynomorphs) and
geochemical investigations on the δ13C of the organic matter of the different sedimentary successions in
the Southern Alps, including those of Collio, Tregiovo and Monte Luco. Macrofossils will be studied, and
a micromorphological study will be also conducted on cuticle material, if available, to get information on
the epidermal features, either with optical and /or SEM microscopy. In order to have a more complete
1
Scuola di Dottorato in Scienze della Terra,
Dipartimento di Geoscienze, Università degli Studi di Padova – A.A. 2014-2015
picture of the regional quantitative and qualitative floral composition, also paleopalynofloras will be
considered. The palynological analysis will highlight changes in the quantitative and/or qualitative
composition of floras, that may reflect environmental and/or climate fluctuations/changes. Concerning
macroremains, the material mostly consists of compression fossils but also include three-dimensionally
preserved plans remains. Part of the material is stored in the collections of the following museums:
MUSE of Trento, Natural History Museum of Wien, Museo Civico di Storia Naturale di Brescia and
Museo di Scienze Naturali dell’Alto Adige of Bolzano/Bozen. Some of these collections were studied
during the seventies (Vacek and Hammer, 1911; Vacek, 1882, 1894; Remy and Remy, 1978; Kozur,
1980; Visscher et al., 2001) but need a taxonomical revision. New, unedited material has been recently
collected (more than 700 slabs with macroremains). Palynological material will be sampled, where
possible on museum collections, but mostly from the stratigraphic sections of the different basins, in
order to conduct a qualitative and quantitative analysis. The palynological and cuticle analyses are
conducted in the Laboratory of micropaleontology of the Department of Geosciences, University of
Padua.
Geochemical analyses carried out on bulk sediment, cuticles, leaves and wood from different layers will
enable to create a δ13C curve, hopefully comparable with the one proposed by DiMichele et al. (2008),
and calibrated on the available radiometrical datas of the basins (Avanzini et al., 2007; Marocchi et al.,
2008). The δ13Corg analyses are to be performed with the Delta V Advantage Mass Spectrometer
connected to a Flash 2000 HT Elemental Analyzer of the Spectrometry Laboratory of the Department of
Geosciences, University of Padua.
First year activities and first results
The first year of my PhD has been focused on the taxonomical study of part of the macroflora form
Tregiovo “Le Fraine” (more that 340 slabs with plant remains). The preliminary results have been
presented with posters and talks in conferences, and have been partly published (Marchetti et al., 2015).
The fossils have been measured by a calliper and with the open source software ImageJ® and classified
macromorphologically, revealing a very rich diverse flora, which includes both hygrophytic and
xerophytic taxa. Few specimens of sphenophytes (hygrophytic plants that reproduce by spores), like
Annularia Sternberg, 1821 occur, together with frond fragments and ovuliferous organs of ferns and seed
ferns (an extinct group) like Lodevia nicklesii (Zeiller) Haubold et Kerp, 1988, Sphenopteris kukukiana
Gothan et Nagalhard, 1921, S. patens (Althaus) Geinitz, 1848, Peltaspermum Harris, 1937 and putative
ginkgophytes like Sphenobaiera Florin, 1936. Nonetheless, the most abundant and diversified group of
plants are conifers. So far the following taxa have been determined: Hermitia Kerp et ClementWesterhof, 1986, Hermitia geinitzii Kerp et Clement-Westerhof, 1986, Feysia Broutin et Kerp, 1994 and
Quadrocladus Mädler, 1957. Moreover, several conifer cones and respective fertile scales have been
found and not yet classified. Conifer remains are very fragmented. Likely, they were transported welldrained soils of the interland. Many shoots of conifers are still undetermined. Comparison with other
conifers from coeval floras will allow to identify them, revealing probably a wider diversity of the
conifers of the Tregiovo flora. Several leaves with uncertain affinities, like Taeniopteris Brogniart, 1828
and Lesleya (al. Taeniopteris) eckardii (Germar) Kurtze 1839 have been identified. For some of them, as
in Morphotype 1, the taxonomical affinity is at present unknown. Most likely they represent a new genus
but this will need further studies in the future.
From these preliminary results on the floral composition, the Tregiovo flora seems to be a transitional
flora including “old-fashion” elements, typical of Carboniferous floras, associated with modern taxa, like
the genus Feysia, a broad-leaved conifer, or Quadrocladus, both considered until recently typical late
Permian conifers. The mixing of old and modern floral elements is not new from literature (DiMichele et
al., 2008).
The discover, in the Tregiovo flora, of some typical late Permian taxa reveals the incompleteness of the
early Permian fossil record, and extends backwards to the early Permian the occurrence ranges of:
Sphenopteris patens, S. kukukiana, Quadrocladus and Lesleya (al. Taeniopteris) eckardii.
2
Scuola di Dottorato in Scienze della Terra,
Dipartimento di Geoscienze, Università degli Studi di Padova – A.A. 2014-2015
On the base of radiometric ages (Avanzini et al., 2007; Marocchi et al., 2008) and palaeobotanical data,
the previous attribution of the upper part of the Tregiovo section to the late Permian by Neri et al. (1999)
is wrong. The precocious occurrence of some taxa is instead confirmed by radiometric ages.
Moreover, the occurrence of very innovating characters in the Tregiovo conifers (e.g., wide morphology
of leaves and fertile scales with “modern” morphology) shows how the mechanisms of evolution of
conifers were complex, precocious, and similarly, local. A new sampling has been done for palynology,
focusing in particular on the two main fossiliferous levels of Tregiovo. Eight samples were prepared in
the Laboratory of micropaleontology of the Department of Geosciences following standard procedures.
This will allow to check if the quantitative difference observed in the macroflora is recorded by
palynomorphs as well and reflects, thus, a true change in the floral composition rather than a preservation
bias of macroremains. A preliminary palynological study has been carried out showing that the
palynomorphs were metamorphised by following volcanic events being thus characterized by dark
(mature) colours. Moreover, the palynomorphs from the lower level seems preserved worse than those
from the upper levels. This is attributable to an intense sulfobacteria activity, visible by the bad
preservation of exine. The study of the samples is still in progress, however, despite the variable
preservation, a high diversity of the palynoflora has been observed in all samples.
Sampling for geochemical analyses has also been done during the field-work. A preliminary set of 16
samples has been washed, powdered and treated with diluted HCl in the Laboratory of micropaleontology
of the Department of Geosciences. This first set of samples will soon be analysed with the Delta V
Advantage Mass Spectrometer connected to a Flash 2000 HT Elemental Analyzer of the Department.
Next future
In the next future I’m going to perform the geochemical analyses on the organic matter of Tregiovo, and a
new sampling of Sinigo, Collio and Monte Luco sections is planned for palynological and geochemical
studies. I will also begin the taxonomical study of the recently collected material from Tregiovo (upper
flora, more than 400 slabs with plat remains). A period abroad at the University of Münster (one month)
is planned, under the supervision of Prof. Hans Kerp, a leading expert on the Permian palaeofloras, in
order to study new taxa from Tregiovo and describe new genera. The measurements on materials from
Collio, stored partly at the Museo Civico di Scienze Naturali di Brescia and partly at the Museum of
Natural Science of South Tyrol of Bolzano/Bozen, will be completed and integrated with palynological
and geochemical data, which will provide a first palaeoenvironmental interpretation.
During the second semester, an abroad period at the University of California, Berkeley is planned (at least
four months), under the supervision of Prof. Cindy Looy, expert on conifers and Permian ecosystems.
The objective is to develop a statistical method (e.g., Looy and Duijnstee, 2013), based on
macromorphological features of leaves, to achieve taxonomical determinations despite the unavailability
of cuticles. During my permanence in the USA, a visiting period at the Smithsonian Institute (Washington
DC) may take place, under the supervision of Prof. Cindy Looy and Dr. William A. DiMichele. A
collection from the Permian of New Mexico, coeval to those of Southern Alps, is stored in Washington
and would allow a comparison between eastern and western Cisuralian palaeofloras. Results obtained
during the second year will be presented in papers and at national and international conferences like
Giornate di Paleontologia SPI (Società Paleontologica Italiana), DGGV-Pangeo Tagung (Innsbruck) or
GSA (Geological Society o America) if compatible with abroad periods.
3
Scuola di Dottorato in Scienze della Terra,
Dipartimento di Geoscienze, Università degli Studi di Padova – A.A. 2014-2015
References
AVANZINI, M., BARGOSSI, G.M., BORSATO, A., CASTIGLIONI, G.M., CUCATO, M., MORELLI,
C., PROSSER, G. and SAPELA, A. 2007. Note Illustrative della Carta Geologica d´Italia, foglio 026:
Appiano. Servizio Geologico d´Italia, APAT. Access Publisher, Roma. ISBN: 978-953-307-468-9.
DIMICHELE, W.A., CECIL, C., CHANEY, D.S., ELRICK, S.D. and NELSON, W.J. 2014. Fossil floras
from the Pennsylvanian-Permian Cuttler Group of southeastern Utah. 491–504. In: MACLEAN, J.S.,
BIEK, R.F., and HUNTOON, J.E. (ed). Geology of Utah’s Far South: Utah Geological Association
Publication, 43..
DIMICHELE, W.A., KERP, H., TABOR, N.J. and LOOY, C.V. 2008. The so-called “PaleophyticMesophytic” transition in equatorial Pangea – Multiple biomes and vegetation tracking of climate
change through geological time. Palaeogeography, Palaeoclimatology, Palaeoecology, 268: 152–163.
DIMICHELE, W.A., PHILLIP, T.L. and NELSON, W.J. 2002. Place vs. time and vegetational
presistance: a comparison of four tropical mires from the Illinois Basin during the height of the
Pennsylvanyan Ice Age. Internationa Journal of Coal Geology, 50: 43–72.
DIMICHELE, W.A., MAMAY, S.H., CHANEY, D.S., HOOK, R.W. and NELSON, J. 2001. An Early
Permian Flora with late Permian and Mesozoic affinities from North Central Texas. Journal of
Palaeontology, 75(2): 449–460.
KNOLL, A.H. 1984. Patterns of extinction in the fossil record of vascular plants. In M. H. NITECKI (ed).
Extinctions. University of Chicago Press, Chicago, 21–6
KOZUR, H. 1980. Beiträge zur Strigraphie des Perms. Teil III (2): Zur Korrelation der überwiegend
kontinentalen Ablagerungen des obersten karbons und Perms von Mittel- und Westeuropa. Freiberger
Forschh., C348: 69–172.
LOOY, C.V. 2007. Extending the range of derived Late Paleozoic conifers: Lebowskia gen. nov.
(Majonicaceae). International Journal of Plant Sciences, 168(6): 957–972.
LOOY, C.V., KERP, H., DUIJNSTEE, I.A.P, DIMICHELE, W.A. 2014. The late Paleozoic ecologicaevolutionary laboratory, a land-plant fossil record perspective. The Sedimentary record, 12(4): 4–10.
LOOY, C.V. and DUIJNSTEE, I. 2013. Characterizing morphologic variability in foliated Paleozoic
conifer braches – A first step in testing its potentials proxy for taxonomic position. New Mexico Museum
of Natural History and Science Bulletin, 60: 215–223.
MARCHETTI, L., FORTE, G., BERNARDI, M., WAPPLER, T., HARTKOPF-FRÖDER, C.,
KRAINER, K. AND KUSTATSCHER, E. 2015 Reconstruction of a Late Cisuralian (Early Permian)
floodplain lake environment: Palaeontology and sedimentology of the Tregiovo Basin (Trentino-Alto
Adige, Northern Italy). Palaeogeography, Palaeoclimatology, Palaeoecology, 440: 180–200. DOI:
10.1016/j.palaeo.2015.08.021
MAROCCHI, M., MORELLI, C., MAIR, V., KLOTZLI, U., BARGOSSI, G.M. 2008. Evolution of
Large Silicic magma System: new U-Pb Zircon Data on the NW Permian Athesian Volcanic Group
(Southern Alps, Italy), Journal of Geology, 116: 480–498.
VACEK, M. 1882. Vorlage der geologischen Karte des Nonsberges. Verhandlungen der kaiserlichköniglich geologischen Reichsanstalt 3: 42–47.
VACEK, M. 1894. Ueber die geologischen Verhältnisse des Nonsberges. Verhandlungen der kaiserlichköniglich geologischen Reichsanstalt 16: 431–446.
VACEK, M. and HAMMER, W. 1911. Erläuterungen zur Geologischen Karte, SW-Gruppe Nr. 79 Cles,.
Verhandlungen der kaiserlich-königlich geologischen Reichsanstalt, Wien. 104.
VISSCHER, H., KERP, J.H.F., CLEMENT-WESTERHOF, J.A. and LOOY C.V. 2001. Permian floras of
the Southern Alps. Natura Bresciana, 25: 117–123.
4
Scuola di Dottorato in Scienze della Terra,
Dipartimento di Geoscienze, Università degli Studi di Padova – A.A. 2014-2015
SUMMARY OF ACTIVITY IN THIS YEAR
Courses:
MONICA BORG: “Consolidating skills in English: A Multimedial Approach”, Dipartimento di Geoscienze, Università degli
Studi di Padova.
PHILIP STARK, LUIGI SALMASO and LIVIO CORAIN: “Statistics for Engineers 2015”, Dipartimento di Ingegneria
Industriale, Università degli Studi di Padova.
C. AGNINI: Paleoecologia e Paleoclimatologia, Dipartimento di Geoscienze, Università di Padova. (in progress).
ROSS J. ANGEL: “Scientific Communication”, Dipartimento di Geoscienze, Università degli Studi di Padova (in progress).
Communications:
FORTE, G., KUSTATSCHER, E., ROGHI, G. AND VAN KONIJNENBURG-VAN CITTERT, J.H.A. 2015. The Kungurian mixed-flora of
Tregiovo: evidence from fossil plants and palynomorphs. XV Edizione delle “Giornate di Paleontologia” – Palermo, 27–29
Maggio, Abstract book p. 61–62.
KUSTATSCHER, E., AND FORTE, G., 2015. La flora fossile di Tregiovo e la sua importanta in un quadro internazionale. – La
flora fossile permiana di Tregiovo – Le Fraine, Val di Non – Trentino. Le piante spontanee e viventi, 22.-23.08.2015, Revò,
Abstract book p. 3–4.
Posters:
FORTE, G., KUSTATSCHER, E., VAN KONIJNENBURG-VAN CITTERT, J.H.A. AND KERP, H. 2015. The Kungurian flora of
Tregiovo (Trento N-Italy). Agora Paleobotanica. Un homage à/ A tribute to Bernard Renault (1836-1904), 6–9/07/2015,
Autun, France, p. 10.
Publications:
MARCHETTI, L., FORTE, G., BERNARDI, M., WAPPLER, T., HARTKOPF-FRÖDER, C., KRAINER, K. AND
KUSTATSCHER, E. 2015. Reconstruction of a Late Cisuralian (Early Permian) floodplain lake environment: Palaeontology
and sedimentology of the Tregiovo Basin (Trentino-Alto Adige, Northern Italy). Palaeogeography, Palaeoclimatology,
Palaeoecology 440: 180–200. DOI: 10.1016/j.palaeo.2015.08.021
Teaching activities:
Teaching assistant: 40 hours, “Paleontologia”, Prof. E. Fornaciari, Laurea di primo livello in Scienze Naturali (2014/2015).
Other: Corso introduttivo all’utilizzo del SEM, Dr. Luca Peruzzo. (15/05/15).
5