Anna Maria Bambini | University of Siena / Università di Siena (original) (raw)
Papers by Anna Maria Bambini
Archaeological and Anthropological Sciences, 2020
Personal ornaments are commonly linked to the emergence of symbolic behaviour. Although their pre... more Personal ornaments are commonly linked to the emergence of symbolic behaviour. Although their presence in Africa dates back to the Middle Stone Age, evidence of ornament manufacturing in 2 Eurasia are sporadically observed in Middle Palaeolithic contexts, and wide diffusion have been until now well documented only since the Upper Palaeolithic. Nevertheless, little is known during the period between ca.50,000 and 40,000 years ago (kya), when modern humans colonized Eurasia replacing existing hominin populations such as the Neandertals, and a variety of so called "transitional" and/or early Upper Palaeolithic cultures emerged. Here we present shell ornaments from the Uluzzian site of Grotta del Cavallo in Italy, southern Europe. Our results show evidence of local production of shell beads for ornamental purposes as well as a trend toward tusk bead standardization over time. The temporal interval of the layers of interest (45-40 kya) makes Cavallo the earliest known shell ornament making context in Europe.
This paper deals with the geological setting of the Rapolano Terme area (Siena) located in southe... more This paper deals with the geological setting of the Rapolano Terme area (Siena) located in southern Tuscany, inner Northern Apennines. The Rapolano area is part of an important morpho-tectonic feature NNW-SSE oriented, ranging from the Chianti Mts to the Cetona Mt, separating the Siena-Radicofani and the Valdichiana Basins in the western and eastern sides, respectively. In the study area the Late Triassic-Early Miocene succession of the Tuscan Nappe, as well as the Eocene succession belonging to the Morello Unit (external Ligurian Unit) and the Pliocene-Pleistocene post-orogenic marine to continental deposits are broadly exposed. The oldest cropping out Tuscan Nappe formation consists of the «Calcari e marne a Rhaetavicula contorta » Fm. It is mainly composed of dark limestone beds with decimeter thick grey marls interbedded. The occurrence of Triasina hantkeni Maizon allows referring this formation to the Rhaetian. The underlying formation (the base of the Tuscan Nappe), represente...
Italian Journal of Geosciences, 2016
The I Sodi section is exposed in the homonymous quarry in the northern sector of the Siena Basin,... more The I Sodi section is exposed in the homonymous quarry in the northern sector of the Siena Basin, one of the most extended Neogene-Quaternary post-collisional basins of the northern Apennines. The section is composed almost exclusively of marine mudstone containing a rich fossil assemblage and has been extensively investigated in past and recent times. It represents a key section to define the time interval of marine deposition in the Siena Basin and more generally in the inner northern Apennines, with important structural and stratigraphic implications.The marine infill of the Siena Basin is traditionally attributed to the Zanclean-Piacenzian (Pliocene) age. However, recently published data provided a more recent age for the I Sodi section (Calabrian, Lower Pleistocene) and, consequently, for the Siena Basin. This paper provides new data on this scientific debate, from sedimentological and biostratigraphical investigations. Analyses of planktonic foraminifera and calcareous nannofossils have been carried out in order to better constrain the depositional age of the section. As a result, this section is now dated more accurately to the Piacenzian and possibly to the lowermost Gelasian in its upper part.
International Journal of Earth Sciences, 2013
The detection of detached nearshore wedges formed in response to relative sea-level drops is cons... more The detection of detached nearshore wedges formed in response to relative sea-level drops is considered one of the hottest topics in sequence stratigraphic analysis due to their importance as reservoir analogues. In fact, they usually constitute sandy and porous bodies generally encased in impermeable clay, thus presenting a good potential as traps for fluids. This paper focuses on the sequence stratigraphic analysis of the Pliocene deposits cropping out in the central-southern sector of the Siena Basin (Tuscany, Italy), a post-collisional basin of the Northern Apennines. The exposed sedimentary succession was investigated through a detailed sedimentological and stratigraphic approach, integrated by biostratigraphic analyses, aimed at a better characterization of the infilling history of this sector of the basin. Specifically, this study revealed the occurrence of repeated facies shifts that allowed the identification of two depositional sequences. In detail, a thick sand-rich body far from the basin margins, and previously considered as a turbiditic lobe, has been reinterpreted as formed in a nearshore setting during a fall in relative sea level. This body is totally encased in offshore clay, and due to the lack of physical connection with the related HST deposits, it has to be considered as a detached forced-regressive wedge. The present work led to the recognition of some sedimentological and stratigraphic features typical of falling stage systems tract deposits (e.g. presence of intrabasinal recycled materials, sedimentological evidence of a pre-existing fluvial network subsequently eroded) that can provide useful clues for the identification of detached forced-regressive nearshore wedges in core studies and poorly exposed settings.
Bollettino- Societa Geologica Italiana
The Scaglia Toscana represents a stratigraphic unit belonging to the Tuscan Domain of the Norther... more The Scaglia Toscana represents a stratigraphic unit belonging to the Tuscan Domain of the Northern Apennines Such a stratigraphic unit results lithologically heterogeneous, and is representative of a very long time span (from the Early Cretaceous to the Oligocene) during which very important geological events took place, such as the convergence and collisional events giving rise to the edification of the Northern Apennines orogene We have studied several key outcrops of the Scaglia Toscana exposed in the Rapolano Termearea (Southern Tuiscany, Northern Apennines) in order to contribute to the reconstruction of the depositional setting and palaeogeographical features of a secotr of the Tuscan Dornain from the Cretaceous to the Early Miocene, and to hypothesise a possible geodynamic evolution The Scaglia Toscana exposed in the Rapolano Terme area has been deply investigated through lithostragraphic and biostratigraphic analyses mainly carried out in three key areas indicated in the fig...
... 52: 513-525. Bossio A., Foresi LM, Mazzei R., Salvatorini G., Sandrelli F., 1996. Evoluzione ... more ... 52: 513-525. Bossio A., Foresi LM, Mazzei R., Salvatorini G., Sandrelli F., 1996. Evoluzione tettonico-sedimentaria neogenica lungo una trasver-sale ai bacini di Volterra e della Val d'Elsa. Studi Geol. Camerti, Volume Speciale 1995/1: 93-104. ... Boll. Soc. Paleont. It. 36: 213-230. ...
INDEX Barbero E., Festa A., Fioraso G. & Catanzariti R. Tectono-sedimentary evolution of the Nort... more INDEX Barbero E., Festa A., Fioraso G. & Catanzariti R. Tectono-sedimentary evolution of the Northern Apennines between Curone and StafforaValleys (NW Italy): new constraints from geological mapping and chaotic rock units differentiation .............................................................................................................................................. 3 Barbero E., Saccani E., Pandolfi L., Marroni M., Delavari M., Dolati A. & Catanzariti R. Preliminary petrological and stratigraphic data on the Band-e-Zeyarat ophiolite (Makran accretionary wedge, SE Iran) .......................... 4 Capponi G., Casale S., Montomoli C., Carosi R., Cox S., Crispini L., Federico L., Iaccarino S., Laufer A., Musumeci G., Salvatore M.C. & Scarsi, M. Geological mapping in the Victoria Land, Antarctica: filling the gap between the GIGAMAP and the GNS maps ......................................................................................................... 5 Carnemolla F., Br...
Italian Journal of Geosciences
The Oligocene-Miocene turbidite successions of the Emilia-Tuscany Apennines are one of the most i... more The Oligocene-Miocene turbidite successions of the Emilia-Tuscany Apennines are one of the most intriguing aspects of the geology of the Northern Apennines (NA) in Italy. To better understand the stratigraphic and tectonic evolution of this sector of the NA, we conducted a detailed field-mapping and stratigraphic study of turbidite successions of the most critical areas of this sector of the chain, which are composed of Mt. Modino Sandstone, Mt. Cervarola Sandstone, Gova Sandstone and associated marly units. Our contribution encompasses a review of the regional geology and fieldrelationships of arenaceous and marly formations, with a particular focus on new biostratigraphic data. This new biostratigraphic study is coupled with a compositional characterization of sandstone, with a view to producing a paleogeographic and evolutionary model of the thrust-foredeep system of the NA during the late Oligoceneearly Miocene. This system was structured in a first stage during the Chattian-Aquitanian with the development of different inner turbidite systems (the Mt. Modino Sandstone in the frontal thrust-top basin, the Macigno, the Torre degli Amorotti System of the Mt. Cervarola Sandstone and the Gova Sandstone in the foredeep). The orogenic wedge was then affected by a later important deformation event during the earliest Burdigalian (Tuscan phase), developing the wider foredeep of the Mt. Cervarola Sandstone basin.
Geobios, 2002
High-resolution calcareous plankton (planktonic foraminifera and calcareous nannofossils) biostra... more High-resolution calcareous plankton (planktonic foraminifera and calcareous nannofossils) biostratigraphy is presented from the Middle to early Late Miocene interval (from 14.45 to 8.86 Ma) at Site 926 (ODP Leg 154, equatorial Atlantic Ocean). The main bioevents used in the low-latitude zonal schemes, and also auxiliary events revealing potential biostratigraphic value have been recognised. The investigated succession ranges from N.10 to N.16
Geobios, 2002
High-resolution calcareous plankton (planktonic foraminifera and calcareous nannofossils) biostra... more High-resolution calcareous plankton (planktonic foraminifera and calcareous nannofossils) biostratigraphy is presented from the Middle to early Late Miocene interval (from 14.45 to 8.86 Ma) at Site 926 (ODP Leg 154, equatorial Atlantic Ocean). The main bioevents used in the low-latitude zonal schemes, and also auxiliary events revealing potential biostratigraphic value have been recognised. The investigated succession ranges from N.10 to N.16
In questa nota è illustrata la geologia dell'area di Rapolano Terme in Provincia di Siena. Tale a... more In questa nota è illustrata la geologia dell'area di Rapolano Terme in Provincia di Siena. Tale area costituisce un segmento di un importante lineamento morfotettonico che, con direzione NNO-SSE, si estende dai Monti del Chianti al Monte Cetona e separa il bacino di Siena-Radicofani ad ovest da quello della Valdichiana ad est. Nell'area di Rapolano affiorano le formazioni triassico-mioceniche della Successione toscana non metamorfica, la Formazione di M. Morello (qui segnalata per la prima volta) ed i sedimenti marini e continentali plio-quaternari, che si sono depositati successivamente alle ultime fasi tettogenetiche del versante occidentale dell'Appennino Settentrionale. Il termine più antico della Successione toscana, affiorante nell'area in esame, è la Formazione dei Calcari e marne a Rhaetavicula contorta, la cui appartenenza al Retico è documentata dalla presenza di Triasina hantkeni MAIZON. La sottostante Formazione anidritica di Burano non compare mai in affioramento ma è stata incontrata dal sondaggio Rapolano 1, alla profondità di circa 900 metri, ed è stata perforata per circa 114 metri senza che sia stata raggiunta la base. Sui Calcari e marne a Rhaetavicula contorta poggia il Calcare massiccio del Lias inferiore, che affiora estesamente nella parte meridionale dell'area in studio. È costituito prevalentemente da calcari di colore grigio chiaro, talvolta dolomitici, massicci o grossolanamente stratificati. Al Calcare massiccio segue il Calcare selcifero, costituito da calcari di colore grigio, più o meno scuro, stratificati e contenenti liste e noduli di selce grigio scura. La sua età è compresa nell'intervallo Hettangiano superiore -Domeriano. In una posizione stratigrafica anomala rispetto agli affioramenti della successione toscana più occidentali, segue il Calcare rosso ammonitico, che mostra rapporti di eteropia sia con la parte sommitale del Calcare selcifero sia con la base delle Marne a Posidonomya. I suoi rapporti di giacitura permettono di assegnare questa formazione all'intervallo Toarciano-Aaleniano. La Formazione delle Marne a Posidonomya compare, in affioramenti poco estesi e discontinui, nella parte settentrionale dell'area in esame, dove sormonta direttamente il Calcare selcifero. Più a sud è presente con spessori sempre più ridotti e, per alcuni chilometri, è sostituita quasi totalmente dal Calcare rosso ammonitico. Essa è costituita da marne e calcari marnosi di colore rosso, giallo o grigio ed è attribuita all'intervallo Toarciano-Calloviano. I Diaspri poggiano sulle Marne a Posidonomya oppure sul Calcare rosso ammonitico oppure direttamente sul Calcare selcifero, mentre passano alla sovrastante Formazione dei Calcari ad Aptici mediante un contatto per alternanza. La loro età è riferita, su basi stratigrafiche, al Calloviano superiore-Titonico inferiore. I Calcari ad Aptici sormontano la Formazione dei Diaspri, alla quale sono legati anche da rapporti laterali. Sono costituiti prevalentemente da calcari di colore giallo, a grana medio-fine con liste di selce rossa, e da calcari marnosi di colore rosso e grigio. Sulla base di una ricca fauna ad Aptici, sono attribuiti al Titonico. I Calcari ad Aptici passano con gradualità alla Maiolica che, nell'area di Rapolano, presenta spessori inusuali per la Toscana meridionale. La formazione è costituita da calcilutiti selcifere, di colore grigio chiaro, ben stratificate. La sua età è compresa fra il Berriasiano e l'Aptiano. Con un contatto netto si passa al Gruppo della Scaglia, qui rappresentata dalle Argilliti di Brolio, dalle Marne siltose ed argilliti marnose rosse di Pod. Le Rossole (correlabili con le Marne del Sugame dei Monti del Chianti), direzione N-S, separando i depositi pliocenici, ad ovest, da quelli pre-neogenici, ad est. Traccia di questa struttura è ben definita dall'allineamento delle sorgenti termali e degli estesi depositi di travertino;
The detection of detached nearshore wedges formed in response to relative sea-level drops is cons... more The detection of detached nearshore wedges formed in response to relative sea-level drops is considered one of the hottest topics in sequence stratigraphic analysis due to their importance as reservoir analogues. In fact, they usually constitute sandy and porous bodies generally encased in impermeable clay, thus presenting a good potential as traps for fluids. This paper focuses on the sequence stratigraphic analysis of the Pliocene deposits cropping out in the central-southern sector of the Siena Basin (Tuscany, Italy), a post-collisional basin of the Northern Apennines. The exposed sedimentary succession was investigated through a detailed sedimentological and stratigraphic approach, integrated by biostratigraphic analyses, aimed at a better characterization of the infilling history of this sector of the basin. Specifically, this study revealed the occurrence of repeated facies shifts that allowed the identification of two depositional sequences. In detail, a thick sand-rich body far from the basin margins, and previously considered as a turbiditic lobe, has been reinterpreted as formed in a nearshore setting during a fall in relative sea level. This body is totally encased in offshore clay, and due to the lack of physical connection with the related HST deposits, it has to be considered as a detached forced-regressive wedge. The present work led to the recognition of some sedimentological and stratigraphic features typical of falling stage systems tract deposits (e.g.
High-resolution calcareous plankton (planktonic foraminifera and calcareous nannofossils) biostra... more High-resolution calcareous plankton (planktonic foraminifera and calcareous nannofossils) biostratigraphy is presented from the Middle to early Late Miocene interval (from 14.45 to 8.86 Ma) at Site 926 (ODP Leg 154, equatorial Atlantic Ocean). The main bioevents used in the low-latitude zonal schemes, and also auxiliary events revealing potential biostratigraphic value have been recognised. The investigated succession ranges from N.10 to N.16 Zones based on planktonic foraminifera, and from NN5 (CN4) to NN10 (CN8) Zones based on calcareous nannofossils. The evolution of the planktonic foraminiferal Globorotalia fohsi lineage appears to be environmentally controlled. The main diagnostic features of the species of this lineage are not always evident, rendering problematic the definition of the N.9/N.10, N.10/N.11 and N.11/N.12 zonal boundaries. Calcareous plankton events have been calibrated on the basis of the Astronomical Scientific Results, College Station, TX (Ocean Drilling Program) 154, pp. 69-82]. The astrobiochronology obtained at Site 926 has been compared with that of the Mediterranean astronomically calibrated deep marine successions, allowing the evaluation of the degree of synchroneity and diachroneity of bioevents. Some bioevents, such as the last occurrence of Globigerinoides subquadratus dated at 11.55 Ma, the last occurrence of Sphenolithus heteromorphus dated at 13.51 Ma and the last common occurrence of Cyclicargolithus floridanus calibrated at 13.32 Ma, are near-synchronous events between the equatorial Atlantic and the Mediterranean area indicating their high biostratigratigraphic value in global correlation. The diachroneity of the last occurrence of Paragloborotalia siakensis, the first occurrence of Neogloboquadrina acostaensis and the last occurrence of Globorotalia peripheroronda between equatorial Atlantic and the Mediterranean reflect a different spatial and temporal distribution of these marker species probably due to a sharp definition of surface plankton provinces related to the latitudinal thermal gradient.
Introduzione 5 Lo strumento biostratigrafico 6 6.1. Caratteri generali 57 6.2. Stratigrafia e Bio... more Introduzione 5 Lo strumento biostratigrafico 6 6.1. Caratteri generali 57 6.2. Stratigrafia e Biostratigrafia 61 6.2.1. Dati analitici 64 6.3. Considerazioni conclusive 71 Conclusioni 72 Bibliografia 73 Tavole fuori testo 90 Autori 91 La Successione toscana pre-avanfossa abbraccia un lungo intervallo di tempo (dal Trias sup. all'Oligocene inf., circa 200 Ma) ed è rappresentata da litofacies carbonatico-silicee e pelitiche indicative di ambienti di sedimentazione molto diversi. I dati biostratigrafici, oltre che carenti e discontinui, non sono omogenei nei diversi intervalli di tempo, sia perché derivanti da studi effettuati in tempi diversi e con riferimenti biostratigrafici diversi, sia per la variabilità delle condizioni paleoambientali e paleoclimatiche, che hanno controllato, in questo lungo intervallo di tempo, lo sviluppo di differenti gruppi di organismi.. Per il Trias sup. il riferimento biostratigrafico è rappresentato dalla fauna a Foraminiferi, ben conosciuta in tutta l'area della Tetide a seguito dei lavori di
Archaeological and Anthropological Sciences, 2020
Personal ornaments are commonly linked to the emergence of symbolic behaviour. Although their pre... more Personal ornaments are commonly linked to the emergence of symbolic behaviour. Although their presence in Africa dates back to the Middle Stone Age, evidence of ornament manufacturing in 2 Eurasia are sporadically observed in Middle Palaeolithic contexts, and wide diffusion have been until now well documented only since the Upper Palaeolithic. Nevertheless, little is known during the period between ca.50,000 and 40,000 years ago (kya), when modern humans colonized Eurasia replacing existing hominin populations such as the Neandertals, and a variety of so called "transitional" and/or early Upper Palaeolithic cultures emerged. Here we present shell ornaments from the Uluzzian site of Grotta del Cavallo in Italy, southern Europe. Our results show evidence of local production of shell beads for ornamental purposes as well as a trend toward tusk bead standardization over time. The temporal interval of the layers of interest (45-40 kya) makes Cavallo the earliest known shell ornament making context in Europe.
This paper deals with the geological setting of the Rapolano Terme area (Siena) located in southe... more This paper deals with the geological setting of the Rapolano Terme area (Siena) located in southern Tuscany, inner Northern Apennines. The Rapolano area is part of an important morpho-tectonic feature NNW-SSE oriented, ranging from the Chianti Mts to the Cetona Mt, separating the Siena-Radicofani and the Valdichiana Basins in the western and eastern sides, respectively. In the study area the Late Triassic-Early Miocene succession of the Tuscan Nappe, as well as the Eocene succession belonging to the Morello Unit (external Ligurian Unit) and the Pliocene-Pleistocene post-orogenic marine to continental deposits are broadly exposed. The oldest cropping out Tuscan Nappe formation consists of the «Calcari e marne a Rhaetavicula contorta » Fm. It is mainly composed of dark limestone beds with decimeter thick grey marls interbedded. The occurrence of Triasina hantkeni Maizon allows referring this formation to the Rhaetian. The underlying formation (the base of the Tuscan Nappe), represente...
Italian Journal of Geosciences, 2016
The I Sodi section is exposed in the homonymous quarry in the northern sector of the Siena Basin,... more The I Sodi section is exposed in the homonymous quarry in the northern sector of the Siena Basin, one of the most extended Neogene-Quaternary post-collisional basins of the northern Apennines. The section is composed almost exclusively of marine mudstone containing a rich fossil assemblage and has been extensively investigated in past and recent times. It represents a key section to define the time interval of marine deposition in the Siena Basin and more generally in the inner northern Apennines, with important structural and stratigraphic implications.The marine infill of the Siena Basin is traditionally attributed to the Zanclean-Piacenzian (Pliocene) age. However, recently published data provided a more recent age for the I Sodi section (Calabrian, Lower Pleistocene) and, consequently, for the Siena Basin. This paper provides new data on this scientific debate, from sedimentological and biostratigraphical investigations. Analyses of planktonic foraminifera and calcareous nannofossils have been carried out in order to better constrain the depositional age of the section. As a result, this section is now dated more accurately to the Piacenzian and possibly to the lowermost Gelasian in its upper part.
International Journal of Earth Sciences, 2013
The detection of detached nearshore wedges formed in response to relative sea-level drops is cons... more The detection of detached nearshore wedges formed in response to relative sea-level drops is considered one of the hottest topics in sequence stratigraphic analysis due to their importance as reservoir analogues. In fact, they usually constitute sandy and porous bodies generally encased in impermeable clay, thus presenting a good potential as traps for fluids. This paper focuses on the sequence stratigraphic analysis of the Pliocene deposits cropping out in the central-southern sector of the Siena Basin (Tuscany, Italy), a post-collisional basin of the Northern Apennines. The exposed sedimentary succession was investigated through a detailed sedimentological and stratigraphic approach, integrated by biostratigraphic analyses, aimed at a better characterization of the infilling history of this sector of the basin. Specifically, this study revealed the occurrence of repeated facies shifts that allowed the identification of two depositional sequences. In detail, a thick sand-rich body far from the basin margins, and previously considered as a turbiditic lobe, has been reinterpreted as formed in a nearshore setting during a fall in relative sea level. This body is totally encased in offshore clay, and due to the lack of physical connection with the related HST deposits, it has to be considered as a detached forced-regressive wedge. The present work led to the recognition of some sedimentological and stratigraphic features typical of falling stage systems tract deposits (e.g. presence of intrabasinal recycled materials, sedimentological evidence of a pre-existing fluvial network subsequently eroded) that can provide useful clues for the identification of detached forced-regressive nearshore wedges in core studies and poorly exposed settings.
Bollettino- Societa Geologica Italiana
The Scaglia Toscana represents a stratigraphic unit belonging to the Tuscan Domain of the Norther... more The Scaglia Toscana represents a stratigraphic unit belonging to the Tuscan Domain of the Northern Apennines Such a stratigraphic unit results lithologically heterogeneous, and is representative of a very long time span (from the Early Cretaceous to the Oligocene) during which very important geological events took place, such as the convergence and collisional events giving rise to the edification of the Northern Apennines orogene We have studied several key outcrops of the Scaglia Toscana exposed in the Rapolano Termearea (Southern Tuiscany, Northern Apennines) in order to contribute to the reconstruction of the depositional setting and palaeogeographical features of a secotr of the Tuscan Dornain from the Cretaceous to the Early Miocene, and to hypothesise a possible geodynamic evolution The Scaglia Toscana exposed in the Rapolano Terme area has been deply investigated through lithostragraphic and biostratigraphic analyses mainly carried out in three key areas indicated in the fig...
... 52: 513-525. Bossio A., Foresi LM, Mazzei R., Salvatorini G., Sandrelli F., 1996. Evoluzione ... more ... 52: 513-525. Bossio A., Foresi LM, Mazzei R., Salvatorini G., Sandrelli F., 1996. Evoluzione tettonico-sedimentaria neogenica lungo una trasver-sale ai bacini di Volterra e della Val d'Elsa. Studi Geol. Camerti, Volume Speciale 1995/1: 93-104. ... Boll. Soc. Paleont. It. 36: 213-230. ...
INDEX Barbero E., Festa A., Fioraso G. & Catanzariti R. Tectono-sedimentary evolution of the Nort... more INDEX Barbero E., Festa A., Fioraso G. & Catanzariti R. Tectono-sedimentary evolution of the Northern Apennines between Curone and StafforaValleys (NW Italy): new constraints from geological mapping and chaotic rock units differentiation .............................................................................................................................................. 3 Barbero E., Saccani E., Pandolfi L., Marroni M., Delavari M., Dolati A. & Catanzariti R. Preliminary petrological and stratigraphic data on the Band-e-Zeyarat ophiolite (Makran accretionary wedge, SE Iran) .......................... 4 Capponi G., Casale S., Montomoli C., Carosi R., Cox S., Crispini L., Federico L., Iaccarino S., Laufer A., Musumeci G., Salvatore M.C. & Scarsi, M. Geological mapping in the Victoria Land, Antarctica: filling the gap between the GIGAMAP and the GNS maps ......................................................................................................... 5 Carnemolla F., Br...
Italian Journal of Geosciences
The Oligocene-Miocene turbidite successions of the Emilia-Tuscany Apennines are one of the most i... more The Oligocene-Miocene turbidite successions of the Emilia-Tuscany Apennines are one of the most intriguing aspects of the geology of the Northern Apennines (NA) in Italy. To better understand the stratigraphic and tectonic evolution of this sector of the NA, we conducted a detailed field-mapping and stratigraphic study of turbidite successions of the most critical areas of this sector of the chain, which are composed of Mt. Modino Sandstone, Mt. Cervarola Sandstone, Gova Sandstone and associated marly units. Our contribution encompasses a review of the regional geology and fieldrelationships of arenaceous and marly formations, with a particular focus on new biostratigraphic data. This new biostratigraphic study is coupled with a compositional characterization of sandstone, with a view to producing a paleogeographic and evolutionary model of the thrust-foredeep system of the NA during the late Oligoceneearly Miocene. This system was structured in a first stage during the Chattian-Aquitanian with the development of different inner turbidite systems (the Mt. Modino Sandstone in the frontal thrust-top basin, the Macigno, the Torre degli Amorotti System of the Mt. Cervarola Sandstone and the Gova Sandstone in the foredeep). The orogenic wedge was then affected by a later important deformation event during the earliest Burdigalian (Tuscan phase), developing the wider foredeep of the Mt. Cervarola Sandstone basin.
Geobios, 2002
High-resolution calcareous plankton (planktonic foraminifera and calcareous nannofossils) biostra... more High-resolution calcareous plankton (planktonic foraminifera and calcareous nannofossils) biostratigraphy is presented from the Middle to early Late Miocene interval (from 14.45 to 8.86 Ma) at Site 926 (ODP Leg 154, equatorial Atlantic Ocean). The main bioevents used in the low-latitude zonal schemes, and also auxiliary events revealing potential biostratigraphic value have been recognised. The investigated succession ranges from N.10 to N.16
Geobios, 2002
High-resolution calcareous plankton (planktonic foraminifera and calcareous nannofossils) biostra... more High-resolution calcareous plankton (planktonic foraminifera and calcareous nannofossils) biostratigraphy is presented from the Middle to early Late Miocene interval (from 14.45 to 8.86 Ma) at Site 926 (ODP Leg 154, equatorial Atlantic Ocean). The main bioevents used in the low-latitude zonal schemes, and also auxiliary events revealing potential biostratigraphic value have been recognised. The investigated succession ranges from N.10 to N.16
In questa nota è illustrata la geologia dell'area di Rapolano Terme in Provincia di Siena. Tale a... more In questa nota è illustrata la geologia dell'area di Rapolano Terme in Provincia di Siena. Tale area costituisce un segmento di un importante lineamento morfotettonico che, con direzione NNO-SSE, si estende dai Monti del Chianti al Monte Cetona e separa il bacino di Siena-Radicofani ad ovest da quello della Valdichiana ad est. Nell'area di Rapolano affiorano le formazioni triassico-mioceniche della Successione toscana non metamorfica, la Formazione di M. Morello (qui segnalata per la prima volta) ed i sedimenti marini e continentali plio-quaternari, che si sono depositati successivamente alle ultime fasi tettogenetiche del versante occidentale dell'Appennino Settentrionale. Il termine più antico della Successione toscana, affiorante nell'area in esame, è la Formazione dei Calcari e marne a Rhaetavicula contorta, la cui appartenenza al Retico è documentata dalla presenza di Triasina hantkeni MAIZON. La sottostante Formazione anidritica di Burano non compare mai in affioramento ma è stata incontrata dal sondaggio Rapolano 1, alla profondità di circa 900 metri, ed è stata perforata per circa 114 metri senza che sia stata raggiunta la base. Sui Calcari e marne a Rhaetavicula contorta poggia il Calcare massiccio del Lias inferiore, che affiora estesamente nella parte meridionale dell'area in studio. È costituito prevalentemente da calcari di colore grigio chiaro, talvolta dolomitici, massicci o grossolanamente stratificati. Al Calcare massiccio segue il Calcare selcifero, costituito da calcari di colore grigio, più o meno scuro, stratificati e contenenti liste e noduli di selce grigio scura. La sua età è compresa nell'intervallo Hettangiano superiore -Domeriano. In una posizione stratigrafica anomala rispetto agli affioramenti della successione toscana più occidentali, segue il Calcare rosso ammonitico, che mostra rapporti di eteropia sia con la parte sommitale del Calcare selcifero sia con la base delle Marne a Posidonomya. I suoi rapporti di giacitura permettono di assegnare questa formazione all'intervallo Toarciano-Aaleniano. La Formazione delle Marne a Posidonomya compare, in affioramenti poco estesi e discontinui, nella parte settentrionale dell'area in esame, dove sormonta direttamente il Calcare selcifero. Più a sud è presente con spessori sempre più ridotti e, per alcuni chilometri, è sostituita quasi totalmente dal Calcare rosso ammonitico. Essa è costituita da marne e calcari marnosi di colore rosso, giallo o grigio ed è attribuita all'intervallo Toarciano-Calloviano. I Diaspri poggiano sulle Marne a Posidonomya oppure sul Calcare rosso ammonitico oppure direttamente sul Calcare selcifero, mentre passano alla sovrastante Formazione dei Calcari ad Aptici mediante un contatto per alternanza. La loro età è riferita, su basi stratigrafiche, al Calloviano superiore-Titonico inferiore. I Calcari ad Aptici sormontano la Formazione dei Diaspri, alla quale sono legati anche da rapporti laterali. Sono costituiti prevalentemente da calcari di colore giallo, a grana medio-fine con liste di selce rossa, e da calcari marnosi di colore rosso e grigio. Sulla base di una ricca fauna ad Aptici, sono attribuiti al Titonico. I Calcari ad Aptici passano con gradualità alla Maiolica che, nell'area di Rapolano, presenta spessori inusuali per la Toscana meridionale. La formazione è costituita da calcilutiti selcifere, di colore grigio chiaro, ben stratificate. La sua età è compresa fra il Berriasiano e l'Aptiano. Con un contatto netto si passa al Gruppo della Scaglia, qui rappresentata dalle Argilliti di Brolio, dalle Marne siltose ed argilliti marnose rosse di Pod. Le Rossole (correlabili con le Marne del Sugame dei Monti del Chianti), direzione N-S, separando i depositi pliocenici, ad ovest, da quelli pre-neogenici, ad est. Traccia di questa struttura è ben definita dall'allineamento delle sorgenti termali e degli estesi depositi di travertino;
The detection of detached nearshore wedges formed in response to relative sea-level drops is cons... more The detection of detached nearshore wedges formed in response to relative sea-level drops is considered one of the hottest topics in sequence stratigraphic analysis due to their importance as reservoir analogues. In fact, they usually constitute sandy and porous bodies generally encased in impermeable clay, thus presenting a good potential as traps for fluids. This paper focuses on the sequence stratigraphic analysis of the Pliocene deposits cropping out in the central-southern sector of the Siena Basin (Tuscany, Italy), a post-collisional basin of the Northern Apennines. The exposed sedimentary succession was investigated through a detailed sedimentological and stratigraphic approach, integrated by biostratigraphic analyses, aimed at a better characterization of the infilling history of this sector of the basin. Specifically, this study revealed the occurrence of repeated facies shifts that allowed the identification of two depositional sequences. In detail, a thick sand-rich body far from the basin margins, and previously considered as a turbiditic lobe, has been reinterpreted as formed in a nearshore setting during a fall in relative sea level. This body is totally encased in offshore clay, and due to the lack of physical connection with the related HST deposits, it has to be considered as a detached forced-regressive wedge. The present work led to the recognition of some sedimentological and stratigraphic features typical of falling stage systems tract deposits (e.g.
High-resolution calcareous plankton (planktonic foraminifera and calcareous nannofossils) biostra... more High-resolution calcareous plankton (planktonic foraminifera and calcareous nannofossils) biostratigraphy is presented from the Middle to early Late Miocene interval (from 14.45 to 8.86 Ma) at Site 926 (ODP Leg 154, equatorial Atlantic Ocean). The main bioevents used in the low-latitude zonal schemes, and also auxiliary events revealing potential biostratigraphic value have been recognised. The investigated succession ranges from N.10 to N.16 Zones based on planktonic foraminifera, and from NN5 (CN4) to NN10 (CN8) Zones based on calcareous nannofossils. The evolution of the planktonic foraminiferal Globorotalia fohsi lineage appears to be environmentally controlled. The main diagnostic features of the species of this lineage are not always evident, rendering problematic the definition of the N.9/N.10, N.10/N.11 and N.11/N.12 zonal boundaries. Calcareous plankton events have been calibrated on the basis of the Astronomical Scientific Results, College Station, TX (Ocean Drilling Program) 154, pp. 69-82]. The astrobiochronology obtained at Site 926 has been compared with that of the Mediterranean astronomically calibrated deep marine successions, allowing the evaluation of the degree of synchroneity and diachroneity of bioevents. Some bioevents, such as the last occurrence of Globigerinoides subquadratus dated at 11.55 Ma, the last occurrence of Sphenolithus heteromorphus dated at 13.51 Ma and the last common occurrence of Cyclicargolithus floridanus calibrated at 13.32 Ma, are near-synchronous events between the equatorial Atlantic and the Mediterranean area indicating their high biostratigratigraphic value in global correlation. The diachroneity of the last occurrence of Paragloborotalia siakensis, the first occurrence of Neogloboquadrina acostaensis and the last occurrence of Globorotalia peripheroronda between equatorial Atlantic and the Mediterranean reflect a different spatial and temporal distribution of these marker species probably due to a sharp definition of surface plankton provinces related to the latitudinal thermal gradient.
Introduzione 5 Lo strumento biostratigrafico 6 6.1. Caratteri generali 57 6.2. Stratigrafia e Bio... more Introduzione 5 Lo strumento biostratigrafico 6 6.1. Caratteri generali 57 6.2. Stratigrafia e Biostratigrafia 61 6.2.1. Dati analitici 64 6.3. Considerazioni conclusive 71 Conclusioni 72 Bibliografia 73 Tavole fuori testo 90 Autori 91 La Successione toscana pre-avanfossa abbraccia un lungo intervallo di tempo (dal Trias sup. all'Oligocene inf., circa 200 Ma) ed è rappresentata da litofacies carbonatico-silicee e pelitiche indicative di ambienti di sedimentazione molto diversi. I dati biostratigrafici, oltre che carenti e discontinui, non sono omogenei nei diversi intervalli di tempo, sia perché derivanti da studi effettuati in tempi diversi e con riferimenti biostratigrafici diversi, sia per la variabilità delle condizioni paleoambientali e paleoclimatiche, che hanno controllato, in questo lungo intervallo di tempo, lo sviluppo di differenti gruppi di organismi.. Per il Trias sup. il riferimento biostratigrafico è rappresentato dalla fauna a Foraminiferi, ben conosciuta in tutta l'area della Tetide a seguito dei lavori di