Marne Di Monte Serrone

The Marne di Monte Serrone ("Monte Serrone Marl") is a geological formation in Italy, dating to roughly between 181 and 178 million years ago,Baldanza, 1989Sabatino et al., 2009 and covering the early and middle Toarcian stage of the Jurassic Period of central Italy. It is the regional equivalent to the Toarcian units of Spain such as the Turmiel Formation, units in Montenegro, such as the Budoš Limestone and units like the Wazzant Formation and the Azilal Formation of Morocco.Monaco, 1994

Description

The Marne di Monte Serrone was first defined by Pialli in 1969.Pialli, 1969

The formation is characterised for be one of the most complete sections of the Toarcian paleobiographical strata around Europe.Palliani & Mattioli, 1994 It is also one of the best places on southern Europe where the strata shows the effects of the Lower Toarcian anoxic event (TAE). The formation also provides data about the changes after the Toarcian AE, with changes on the deposited micritic limestones and marls, what shows a local sedimentary response to the Toarcian climatic perturbation induced by the Vulcanism of the Southern Karoo-Ferrar that boiled the carbon cycle and change the mechanism of Earth climate. The dawn after the Toarcian AE is presented locally by changes on the environments, to more seashore to lagoonal ones.Satolli et al., 2018

Depositional environment

The environment of the formation has been compared to the present on the Toarcian Betic Cordillera strata, with a corridor of pelagic environments with influence from emerged reliefs.Nini et al., 1996 Other sections are related to nearby emerged lands, seashore deposits and even inland deposition, due to the changes in lithology (especially with the clay minerals kaolinite and smectite). Due to that, the main depositional layers of the formation are believed to come from an environment intermediate between pelagic and nearshore settings.Parisi et al., 1996

Due to the influence of different depositional settings, the lithology of the formation was widely distributed, with changes on the mineralological composition. The clay Mineral assemblages, with the neritic sedimentation, expose a change on the deposition, as it can be seen on the Valdorbia Section, where on the Middle Toarcian the reduction of this minerals indicate a sea-level fall, with a change from a bathyal to a middle shelf environment. Additionally there is a record of changes on the fauna, specially bivalves that suggests a variable flow regime at the major wave base as a result of a storm event.Ortega Huertas et al., 1993

Fossil content

The biota of the formation comprise mostly marine microinvertebrates and algae, with the presence of ammonites and abundant pollen in the Middle Toarcian sections. Nanoplankton is one of the most representative finds of the layers, appearing deposited with interruptions, probably due to changes on the oxygen content of the sea floor.Noël et al., 1993 Phytoplankton includes abundant dinoflagellate cysts and acritarchs, specially the genus '' Micrhystridium''. There registered a transgression on the sea level on the Lower Toarcian, with a rise, giving the Umbria-Marche Basin pelagic conditions, and a regression during the Middle Toarcian. Those changes implicate the disappearance of genera of dinoflagellates from the strata to be replaced with new ones.Palliani et al., 1998Palliani et al., 1999 Some dinoflagellate genera such as '' Mendicodinium'' are more abundant in the Marne di Monte Serrone than in any other unit discovered until 1997.Palliani et al., 1997

Foraminiferal analysis had been done, revealing changes in the salinity, with '' Spirillina'' as the most abundant genus found, followed by '' Prodentalina'', '' Eoguttulina'', '' Lenticulina'', '' Nodosaria'', '' Lingulonodosaria'' and '' Pseudonodosaria''.Rodríguez Tovar et al., 2016 Invertebrate remains are mainly brachiopods ('' Pseudokingena'', '' Nannirhynchia'' and '' Lokutella'', among others) and ammonites; '' Eodactylites'', '' Pleuroceras'', '' Canavaria'', '' Trinacrioceras'', '' Lioceratoides'', and '' Praepolyplectus'' as predominant genera.Bilotta et al., 2010

Other marine fauna includes Holothuriidan ''Sclerites'', unidentified crinoids, fragmentary asteroideans and fish teeth, similar to the genera '' Saurostomus'' and ''Dapedium''.Monaco et al., 1994

There are terrestrial fossils and sediments, specially clay. The main source area for the clay could have been the palaeosoils developed on the Carbonate Latium-Abruzzo Platform, although more recent studies prove a continental origin.Perilli et al., 2008 The Main fossils from terrestrial deposits are plant Pollen, mostly Pteridophyta spores and Circumpolles, and Palynomacerals.Palliani & Riding, 1997 The genera includes '' Leptolepidites'' (Lycopsida) spp., '' Trilites'' (Filicopsida) spp., '' Ischyosporites'' (Pteridopsida) spp. or '' Foveosporites'' (Selaginellaceae) spp. and others less abundant, such as the genus '' Callialasporites'' (Coniferales).

There is a curious reduction of the Cheirolepidiaceae genus '' Classopollis'', abundant on coeval associations from northern Europe, Portugal, northeast Italy and Israel, as a possible effect of paleoclimatic changes.Palliani, 1997 In 2019 was recovered that Marne di Monte Serrone seashore section was part of the now lost continent of Greater Adria, with the confirmation of a continental origin for the plant matter, as was proposed in 1997.Van Hinsbergen et al., 2019

See also

* Azilal Group, North Africa
* Calcare di Sogno, Italy
* Mizur Formation, North Caucasus
* Cattamarra Coal Measures, Australia
* Djupadal Formation, Central Skane
* Ciechocinek Formation, Germany and Poland
* Irlbach Sandstone, Germany
* Fernie Formation, Alberta and British Columbia
** Poker Chip Shale
* Kandreho Formation, Madagascar
* Kota Formation, India
* Krempachy Marl Formation, Poland and Slovakia
* Lava Formation, Lithuania
* List of fossiliferous stratigraphic units in Italy
* Los Molles Formation, Argentina
* Mawson Formation, Antarctica
* Navajo Sandstone, Utah
* Posidonia Shale, Lagerstätte in Germany
* Saubach Formation, Austria
* Sachrang Formation, Austria
* Whitby Mudstone, British Columbia
* :Toarcian Stage

References

Bibliography

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* {{cite LSA , last=Perilli , first=N. , last2=Reale , first2=V. , last3=De Oliveira , first3=L.C.V. , year=2008 , title=Ages of the onset of marly sedimentation and of the black shales in the Tuscan Basin (Northern Apennines, Italy) , url=https://www.researchgate.net/publication/286900981_Ages_of_the_onset_of_marly_sedimentation_and_of_the_black_shales_in_the_tuscan_basin_Northern_Apennines_Italy , journal= Rivista Italiana di Paleontologia e Stratigrafia , volume=114 , pages=45–60 , accessdate=2020-03-17
* Palliani, R. B., & Riding, J. B. (1999). Relationships between the early Toarcian anoxic event and organic-walled phytoplankton in central Italy. Marine Micropaleontology, 37(2), 101-116
* Palliani, R. B., Cirilli, S., & Mattioli, E. (1998). Phytoplankton response and geochemical evidence of the lower Toarcian relative sea level rise in the Umbria-Marche basin (Central Italy). Palaeogeography, Palaeoclimatology, Palaeoecology, 142(1-2), 33–50.
* Palliani, R. B., Riding, J. B., & Torricelli, S. (1997). The dinoflagellate cyst Mendicodinium Morgenroth, 1970, emend. from the lower Toarcian (Jurassic) of central Italy. Review of Palaeobotany and Palynology, 96(1-2), 99-111
* Palliani, R. B., & Riding, J. B. (1997). Lower Toarcian palynostratigraphy of Pozzale, central Italy. Palynology, 21(1), 91-103.
* Palliani, R. B. (1997). Toarcian sporomorph assemblages from the Umbria‐Marche basin, central Italy. Palynology, 21(1), 105–121.
* Nini, C., Nocchi, M., & Venturi, F. (1996). The Toarcian marly-calcareous succession in the M. Martani area (Northern Apennines): lithostratigraphy, biostratigraphy, paleoecology and effects of Tethysian event on the depositional environment. BOLLETTINO-SOCIETA PALEONTOLOGICA ITALIANA, 35, 281–320.
* Monaco, P. (1994). Hummocky cross-stratifications and trace fossils in the Middle Toarcian of some sequences of Umbria-Marche Apennines. Geobios, 27, 679–688.
* Monaco, P., Nocchi, M., Ortega Huertas, M., Palomo, I., & Martínez, F. (1994). Depositional trends in the Valdorbia Section (Central Italy) during the Early Jurassic, as revealed by micropaleontology, sedimentology and geochemistry. Eclogae Geologicae Helvetiae, 87(1), 157-223
* Bucefalo Palliani, R., & Mattioli, E. (1994). Enrichment in organic matter within the Early Toarcian Marne di Monte Serrone Formation: a synchronous event in the Umbria-Marche Basin (central Italy). Paleopelagos, 4, 129–140.
* Noël, D., Busson, G., Cornée, A., & Manginin, A. M. (1993). Le nannoplancton calcaire et la formation des alternances calcaires-marnes dans le Lias des bassins de Marches-Ombrie (Italie). Rivista italiana di paleontologia e stratigrafia, 99(4).
* Ortega Huertas, M., Monaco, P., & Palomo, I. (1993). First Data on Clay Mineral Assemblages and Geochemical Characteristics of Toarcian Sedimentation in the umbriamarche basin (central Italy). Clay Minerals, 28(2), 297–310.
* Baldanza, A. (1989). The type section of Marne di Monte Serrone Formation: stratigraphic analysis based on ammonites, calcareous nannofossils and foraminifera assemblages. Mesozoic Cenozoic Stratigraphy in the Umbria-Marche Area. Mere. Descr. Carta Geol. Ital, 39, 185.
* Pialli, G. (1969). Un episodio marnoso del Lias superiore nel bacino umbro-marchigiano: le marne di M. Serrone. Stabilimento tipografico Genovese.

Geologic formations of Italy
Jurassic System of Europe
Toarcian Stage
Jurassic Italy
Marl formations
Open marine deposits
Fossiliferous stratigraphic units of Europe
Paleontology in Italy
Formations
Formations