Bollettino SPI Vol. 36 - Issues 1-2, 3
Issues 1-2
Published in December 1997
- Abbazzi L., Albianelli A., Ambrosetti P., Argenti P., Basilici G., Bertini A., Gentili S., Masini F., Napoleone G. & Pontini M.R. (1997)
Paleontological and sedimentological record in Pliocene distal alluvial fan deposits at Cava Toppetti (Todi, Central Italy)
pp. 5-22
The Tiberino Basin is a Plio-Quaternary intermontane basin located in Central Italy (Umbria). This paper deals with the sedimentological, mammalofaunistical, and palynological aspects of the deposits of the Ponte Naja Formation (Late Pliocene), outcropping at Cava Toppetti and with the magnetostratigraphical data from the underlying Fosso Bianco Formation (Middle-Late Pliocene) outcropping at the same site.
In the Ponte Naja Formation, sheet flow deposits and paleosols constitute 98% of the sedimentological succession and they alternate with each other cyclically. The plausible short development time of the paleosols made it possible to identify each couplet as a high frequency cyclical depositional sequence.
From these sediments scattered, fragmented large and small mammal remains were found. Taking into consideration the inferred high sedimentation rate, the faunal assemblage may be considered as a local fauna which, owing to its taxonomic composition and in particular to the occurrence of the deer Pseudodama cf. P. rhenana can be attributed to the Middle Villafranchian. Paleomagnetic analysis of the underlying Fosso Bianco Formation, is in agreement with the mammal biochronology of the Ponte Naja Formation, restricting chronological attribution to the time interval of the Late Pliocene, more recent than the Reunion event, judging from the deposition of the alluvial fan deposits.
All the mammal bones occur in the paleosols, except for a scapula of a rhino which comes from sheet flow deposits.
The sheet-flow deposits have a rich and diversified pollen assemblage; paleosols are very poor in pollen grains, whereas Pteridophyta spores (mainly Pteridaceae) are abundant. The occurrence of selective degradation in some paleosols explains the strong difference between their palynomorph content and that of the sheet-flow deposits. Nevertheless, climatic influence cannot be ignored. Throughout the succession a complete climatic cycle and part of the following one can be established should further more detailed analyses support the climatic interpretation.
- Basilici G., Martinetto E., Pavia G. & Violanti D. (1997)
Paleoenvironmental evolution in the Pliocene marine-coastal succession of Val Chiusella (Ivrea, NW Italy)
pp. 23-52
A multidisciplinary study was carried out in order to define the paleoenvironmental evolution in the Pliocene succession of Val Chiusella, cropping out at the foothills of the Western Alps. The succession, about 80 m thick, was divided into three informal sedimentary units. The lower unit, referable to the uppermost Zanclean, provides foraminiferal and mollusc assemblages indicating an infralittoral environment. Sedimentological analysis of the second unit confirms its deposition on a tidal sandy flat. Its upper part shows a coarsening-upward sequence, interpreted as the progradation of an estuary closed by a fluvial body (6-8 m thick) forming the top of the second unit. The bulk of the third unit (47 m thick) is made up of sands and muds deposited under variable subtidal, intertidal and supratidal conditions. The paleoenvironment periodically supported woody and herbaceous plant communities, growing in hypohaline or freshwater conditions. Plant macrofossils indicate that the whole succession was deposited under a warm temperate climate, before 3 Ma.
- Bernasconi M.P., Corselli C. & Carobene L. (1997)
A bank of the scleractinian coral Cladocora caespitosa in the Pleistocene of the Crati valley (Calabria, Southern Italy): growth versus environmental conditions
pp. 53-61
This paper deals with a coral bank interbedded in Pleistocene silty sands which outcrop in the Crati valley (Calabria, Southern Italy). The morphometric analysis of several colonies of Cladocora caespitosa (Linnaeus) is based on measurements concerning both the colony and the individual corallite. The significant correlations obtained from a statistical analysis indicate that the regular and unchanged growth of the bioconstructions occurred in quite a dim environment, and a deep infralittoral allocation is also suggested by the associated molluscan fauna. The paleoenvironment suffered a sudden, strong sediment input, correlated to tectonic activity, which caused the burial of the colonies. The re-colonization of the bottom took place while the bathymetric conditions remained unchanged. The definitive burial of the coral bank is marked by a transgressive phase which yielded the deposition of circalittoral clayey sediments.
- Bertoldi R. (1997)
Palynostratigraphical outlines of Pliocene-basal early Pleistocene continental deposits in north-western Italy
pp. 63-73
This paper is a synthesis of the palynological studies carried out in the fast few years on the lacustrine sediments of the intermontane continental basins in the north-western Apennines (Magra and higher Taro valleys) and on the fluvio-lacustrine deposits in western Piedmont (Villafranca d’Asti and Levone Canavese).
We had several aims: – to get a clear picture of the floristic-vegetational and climatic development during the Pliocene and early Pleistocene periods; – to find a palynological succession, based on successive floral extinctions, as a basis for palynostratigraphical correlations; – to contribute to the solution to the problem of dating these deposits, which are scattered discontinuously in time and space. These studies were carried out together with the stratigraphical-paleontological studies.
Both the north-western Apennine basins and the Piedmontese deposits show very rich pollen floras (about 100 pollen taxa), dominated by arboreal elements, and by complex vegetational successions.
Synthetic pollen diagrams for each deposit are presented, arranged according to the phytogeographical-ecological requirements of their modern representatives. Eight pollen groupings can be recognized:-(1) Tropical-subtropical elements; -(2) Taxodiaceae group; -(3) Mediocratic taxa (i.e. deciduous forest elements); -(4) Pinus sum; -(5) Tsuga+Cedrus; -(6) Mountain elements; -(7) Other arboreal plants (AP); -(8) Non-arboreal plants (NAP).
Prominent paleofloral and palynological features of the sequences examined are the presence and abundance of so-called “Tertiary” elements, that is, the grouping of the tropical-subtropical elements (Symplocos, Clethraceae/Cyrillaceae, Sapotaceae, Rhoiptelea, Magnolia-type, Castanopsis, cf. Trigonobalanus and other tricolporate Fagaceae-type, Theaceae, Rutaceae, besides Bombax-type, Reevesia and Itea) and the Taxodiaceae group (Taxodium/Glyptostrobus-type, Sequoia/Cryptomeria-type, Sciadopitys, Nyssa, Myrica, Celastraceae, archaic Juglandaceae-type, Hamamelis, Distylium and other tricolpate Hamamelidaceae).
These two pollen assemblages reveal the rather archaic character of the pollen floras investigated. The former is mainly confined to the pre-Pliocene – early Pliocene interval and the latter to the pre-Pleistocene periods in central-western Europe. Therefore they are stratigraphically significant.
The results of the pollen analyses, particularly in the N-W Apennine basins, reveal the abundance and floral richness of the tropical-subtropical elements in the Sarzana pollen sections; these elements, which already appear qualitatatively and quantitatively impoverished in the Aulla and Vallescura sections, are rare or non-existent in the Sesta Godano profile. The Taxodiaceae group, in contrast, is always dominant in these records. In the Pontremoli sequence all “Tertiary” elements are absent. In the Compiano succession, only the basal sediments are characterized by an abundance of Sciadopitys and Taxodium-type, while the overlaying layers do not contain “Tertiary” elements.
In the western Piedmont basin, the Rio Ca’ Viettone deposit is characterized by the abundance of “Tertiary” taxa, and especially by a rich tropical-subtropical pollen flora, while this group is absent or at most present only in traces in the succession of the RDB quarry, Villafranca d’Asti basin.
The sequence of floral exinctions suggests a succession of vegetal biozones which may be used to correlate palynostratigraphically the various pollen sequences.
A chronostratigraphic collocation of the pollen records is tentatively correlated to pollen biozones of marine and non-marine sections of Northern ltaly calibrated by faunal and/or paleomagnetic data.
These results show that the chronostratigraphic range of the tropical-subtropical elements in Northern ltaly is mainly confined to the early Pliocene. They may penetrate the overlying basal middle Pliocene, where they become gradually impoverished and then disappear.
A stratigraphic scheme of the paleofloristic evolution in Northern ltaly during the Upper Neogene – Early Pleistocene interval is proposed. This scheme, still largely temporary, reflects the current state of research advancement.
- Bianucci G. (1997)
Hemisyntrachelus cortesii (Cetacea, Delphinidae) from the Pliocene sediments of Campore Quarry (Salsomaggiore Terme, Italy)
pp. 75-83
Two new finds of Hemisyntrachelus cortesii (Cetacea, Delphinidae) from Pliocene clays at the Campore quarry near Salsomaggiore Terme (Italy) are recorded. The two specimens are described and comparisons among the fossil genus Hemisyntrachelus (recently re-evaluated by the author) and Tursiops are made. From a phylogenetic point of view, it is possible that Hemisyntrachelus and Tursiops are less specialized genera and that they are the sister groups respectively of the Globicephalinae and Delphininae subfamilies. Hemisyntrachelus, with its larger size and smaller number of teeth than Tursiops, was probably a generalist predator like the extant Pseudorca and perhaps the contemporary Orcinus citoniensis. Discoveries of Hemisyntrachelus are relatively common in the peri-Adriatic area but rare in Tuscany. This distribution indicates a possible provincialism in the Pliocene Mediterranean cetacean populations like that of today.
- Bianucci G., Cantalamessa G., Landini W., Ragaini L. & Valleri G. (1997)
Paleontological and sedimentological observations on the Canoa Formation (Manabí Basin, Ecuador)
pp. 85-96
A succession of 150 m thick sediments, belonging to the Canoa Formation, was studied. Some specifications on past contradictory descriptions of the formation are provided. These sediments consist of a cycle of the first order and outcrop along the coast, south of Manta (Ecuador), between Punta Canoa and Quebrada El Mangle and have been attributed to a Late Pliocene age (Globigerinoides fistulosus Zone). The fossil assemblages are very rich and well differentiated: foraminifers, molluscs and otoliths (the latter being observed for the first time in this formation). On the basis of lithology and of sedimentologic and paleontologic characteristics, offshore/shoreface environments with foreshore episodes were recognized and a hypothesis for a possible geological evolution of the area was suggested.
- Bonfiglio L., Insacco G., Marra A.C. & Masini F. (1997)
Large and small mammals, amphibians and reptiles from a new late Pleistocene fissure filling deposit of the Hyblean Plateau (South Eastern Sicily)
pp. 97-122
The fossil vertebrates recovered from two deposits (Pocket A and B) filling a karst cavity in the Ragusa carbonatic platform at Contrada Pianetti are described. In pocket A only Elephas cf. mnaidriensis and Leithia ex gr. melitensis-cartei are present, while pocket B yielded remains of Bos primigenius, Cervus elaphus siciliae, Canis cf. lupus, Ursus cf. arctos, Erinaceus europaeus, Crocidura sp., Microtus (Terricola) ex gr. savii, an indeterminate bat, Bufo cf. viridis, Lacerta sp., Coluber viridiflavus, Testudo aff. hermanni, indeterminate snakes and birds. The first assemblage, although very poor, can be confidently attributed to the E. mnaidriensis faunal complex which ranged in Sicily from the late middle Pleistocene to the early late Pleistocene. The second and more diversified assemblage has some distinctive features suggesting it may represent a previously unknown phase of population of the Sicilian island which is intermediate between the E. mnaidriensis complex and the latest Pleistocene Castello complex. Taphonomic considerations suggest that Pocket B may have acted prevalently as a trap for vertebrates dying in the immediate neighbourhood of the cavity, while the vertebrate association suggests a landscape with discontinuous forest cover indicative of a rather arid climatic phase.
The finds of Leithia, Crocidura and of M. (Terricola), have distinctive features differing from those currently known concerning the same taxa in Sicily, and suggest that a careful study of the small mammal assemblages could enhance the detail of the biochronological scale of the Pleistocene vertebrates of Sicily.
- Cantalamessa G., Didaskalou P., Micarelli A., Pennesi T. & Potetti M. (1997)
Depositional environments and microfaunal associations in the Sicilian of the Periadriatic Marche Basin (Central Italy)
pp. 123-134
A detailed stratigraphic-sedimentologic study was carried out on the top sediments of the Plio-Pleistocene marine cycle in the southern Marche. The identification, in most of the study area, of an unconformity surface in the upper part of the Plio-Pleistocene marine succession, correlatable to the Emilian regression of Ruggieri (1980), allowed these sediments to be attributed to the Sicilian. Only in a small part of the study area was it possible to recognize with certainty the Sicilian, by the occurrence of Globorotalia truncatulinoides excelsa. The features of the sediments of the two areas are indicative of two environments characterized by different depths. In most of the study area, in fact, they are made up of alternations of sandstones and conglomerates which depict different submarine shore environments (lower shoreface, upper shoreface and foreshore), characterizing, throughout the general regressive trend, minor sea-level fluctuations. Palaeontologic features reflect these environmental changes: it is a question of shallow environments characterized by associations prevalently made up of benthic Foraminifera and lacking in stratigraphically meaningful forms. The Sicilian sediments found in the vicinity of Porto S. Giorgio, however, are made up of pelites with a rich association, both benthic and planktic. In particular the benthic forms are indicative of a relatively deep environment (epibathyal) and among the planktic ones well-developed individuals of Globorotalia truncatulinoides excelsa give evidence for a depositional environment below 100 m depth. The existence of two depositional environments, characterized by different depths, should be related to the reactivation of the previous Emilian faults, in the easternmost part of the study area.
- Carboni M.G. & Di Bella L. (1997)
The Plio-Pleistocene of the Anzio coast (Rome)
pp. 135-159
The topic of this paper is part of a wider biostratigraphic and paleoecologic research on Neogene-Quaternary sequences of the Tyrrhenian coast South of Rome. The work regards the foraminiferal assemblages of Plio-Pleistocene sediments outcropping along the coast extending from Tor Caldara to Anzio. Previous geological-structural studies had shown a structural high corresponding to an anticline with its axis in Tor Caldara.
All the samples collected from North (Tor Caldara) to South (Anzio) were analysed qualitatively, but those having a low degree of reworking and a significant microfaunal amount were also analysed quantitatively. The more ancient sediments (predominantly clayey) constitute the nucleus of the anticline (Tor Caldara) and are subhorizontal. These sediments are attributed to the Globorotalia margaritae Zone (MPL2, Zanclean), and to the upper epibathyal environment. A stratigraphic hiatus due to absence of the Globorotalia margaritae/Globorotalia puncticulata Zone (MPL3) occurs. Southwards, in Tor Materna, Lido delle Sirene and Lido di Marechiaro, exposures of weakly inclined, clayey and clayey-sandy deposits are found, belonging to the Globorotalia puncticulata Zone (MPL4, Zanclean). Their foraminiferal assemblages suggest a poorly oxygenated circalittoral environment with local more anaerobic episodes. In Tor Materna, Lido di Marechiaro, Anzio Colonia and Villa di Nerone the sediments are assigned to the Globorotalia aemiliana Zone (MPL5), characterized by an increasing coarseness of lithologies: from clayey-sandy terms and silty sands to more or less cemented sands and biocalcarenites, with dipping towards ESE of about 5° to 20°. The boundary with the sediments attributed to the Globorotalia puncticulata Zone, was not identified, owing to the lack of data on this portion of the coast. The lower part of the Globorotalia aemiliana Zone, where the marker is associated with Globorotalia bononiensis, was ascribed to the Piacenzian stage, while the upper part with the same marker associated with Bulimina marginata can be attributed to the Gelasian stage. The Piacenzian/Gelasian boundary was thought to correspond to the disappearance of Globorotalia bononiensis. The depositional environment ranges from circalittoral (finer sediments) to infralittoral (sands and “Macco” biocalcarenites) closing the marine Pliocene sequence.
The Lower Pleistocene sediments (Globigerina cariacoensis Zone) transgressively overlie the Pliocene ones (Globorotalia margaritae and Globorotalia puncticulata Zones); they are subhorizontal and consist of clayey-sandy lithologies and more or less cemented sands. The foraminiferal assemblages have typical Early Pleistocene species, such as Bulimina etnea and Globigerinoides tenellus. The Pleistocene sequence base shows a level with Arctica islandica and Terebratula ampulla.
- Cirone G., Raineri V. & Brunetti M. (1997)
Remarks about some species belonging to the Foresti Collection, stored in the “G. Doria” Natural History Museum of Genoa
pp. 161-167
The most significant results as to the recovering of the Foresti collection, composed of Pliocene molluscs from Castell’Arquato (Piacenza, Northern Italy), are reported.
Alt the material stored underground at the “G. Doria” Natural History Museum of Genoa has been damaged by floods which have occurred frequently in the past. Although the Foresti collection was one of the least damaged palaeontological collections in the Museum, the recovery work was made difficult owing to the lack of a catalogue for the 712 specimens (7 Bivalvia and 705 Gastropoda) composing the collection.
During the revision of the collection, the specimens were reidentified, relabelled and catalogued. The catalogue numbers here reported refer to the new Palaeontological Register of the Museum, which replaces the old and incomplete registers occasionally made over the years.
180 taxa (175 Gastropoda and 5 Bivalvia), some of which were very interesting, were recognized; among the gastropods, Neogastropoda and in particular the Nassariidae and Turridae families are well represented, probably because this collection represents only a part of the original Foresti collection.
In this paper a brief description of some specimens belonging to taxa described by Foresti and not well known in literature, such as Nassarius guidicinii, Nassarius fornasinii and Pollia bellardiana, is given.
Also considered are some taxa recognized as new by Foresti but never described in his works and still considered as nomina nuda (Uromitra piacentina, Drillia striatissima, Mangilia bellardii, Bulla piacentina), some varieties considered as synonymous with nominal taxa (Pisania maculosa var. magna, Fusus rostratus var. bononiensis) and some taxa defined in schaedis by Foresti as new varieties (Nassa mutabilis var. scalarioides, Nassa mutabilis var. striata, Nassa reticulata var. minor, Mangilia attenuata var. turgida).
- Conti C. (1997)
Astronomical Tuning of Planktonic Foraminiferal Records from the Radicofani Basin (southern Tuscany, central Italy)
pp. 167-177
A study of planktonic foraminiferal assemblages in the Neogene Radicofani Basin (Tuscany, central Italy) is reported. The sequences analysed are represented by clays and silty clays with thin turbiditic layers and the basin is characterized by a high sedimentation rate and the lack of key-beds. Factor analyses on planktonic foraminifera and some climatic proxy records, such as ratio of planktonic versus planktonic plus benthic foraminifera (PIP+B), sea surface productivity (SSP) and sea surface temperature (SST), were carried out.
Spectral analyses were applied to factor analysis results and climatic proxy record patterns and showed power spectra with frequencies comparable with the orbital cycles of precession and obliquity of the Earth. Moreover, it was possible to take out the orbital components from raw data and correlate them to the astronomical curves, using two bioevents, Globorotalia puncticulata FO and Dyscoaster asymmetricus FCO, as calibration points.
Since these planktonic foraminifera abundance fluctuations were calibrated to astronomical curves, they were used to age-calibrate the studied sections. So these variations could be an important tool in areas where stratigraphic correlations are difficult.
- Di Dio G., Lasagna S., Preti D. & Sagne M. (1997)
Stratigraphy map of the Quaternary deposits of Parma Province
pp. 179-187
The geologic map of Quatemary deposits of Parma Province, presented in this paper, refers to the foothills of the apennines and the middle-upper Po alluvial plain between the Enza and Stirone rivers.
The Quatemary deposits were mapped on surface and in subsurface using Unconformity Bounded Stratigraphic Units (U.B.S. U.), in accordance with ltalian Geological Survey standards.
The mapped units are:
Marine Quaternary Supersynthem Qm (divided into 3 synthems: Qm1, Qm2, Qm3).
Emilian Supersynthem ESS (divided into 2 synthems: Lower Emilian Synthem LES, Upper Emilian Synthem UES).
The basin geometry is of the “complex type” (sensu Ricci Lucchi, 1986) with a thrust-based basin (satellite basin) marginal to a foredeep.
Tectonics, active during the Quaternary System, determined the geometry of the sedimentary basin and produced its segmentation into two different geostructural sectors. The sector located between the Stirone and Parma rivers was characterized by slow subsidence and was involved in low intensity tectonic movements. Therefore the sedimentary sequences are generally thin. In contrast the sector located on the East side of the Parma river was characterized by fast subsidence stacking thicker sedimentary sequences with considerable angular unconformities.
- Di Geronimo I., D’Atri A., La Perna R., Rosso A., Sanfilippo R. & Violanti D. (1997)
The Pleistocene bathyal section of Archi (Southern Italy)
pp. 189-212
A 9 m thick section at Archi (Calabrian side of the Messina Straits) has been studied. It is a mainly pelitic sequence, whose age ranges from the MNN 19e to the MNN 19f nannofossil Zones (upper part of Early Pleistocene – lower part of Middle Pleistocene). The deposition occurred during a cold phase, as inferred from the planktonic foraminiferal assemblages. Benthic faunas (foraminifers, molluscs, bryozoans and serpulids) are ecologically homogeneous, both in composition and structure. They testify a bathyal palaeoenvironment, 500 to 1,000 m deep.
Compositional, structural and taxonomical features of the palaeocommunities indicate a strong affinity with the present day North Atlantic or oceanic conditions in general. A psychrosphaeric palaeoceanographic model, with bottom temperatures lower than 8°- 10° C, strikingly different from the Recent Mediterranean one, can be elaborated from the Archi palaeocommunities.
Two distinct depositionary episodes have been recognized along the section. They were probably related to hydrodynamic phases, as well as to the synsedimentary tectonics in the area.
- Foresi L.M., Pascucci V. & Sandrelli F. (1997)
Miocene Ponsano Sandstone (Tuscany, Italy): paleoenvironmental and bio-chronostratigraphic evolution
pp. 213-230
– Benthonic and planktonic foraminifers of the Middle-Upper Miocene sediments of the Ponsano Sandstone were studied. The outcrops investigated are located at Ponsano (SE of Siena) and Rencine (NW of Siena) in Tuscany. Some studies on these sediments have been done in the past to define the age and the characteristics of the abundant fauna contained in the sandstones, but no environmental analyses were performed.
The aim of this study is to define the thickness of the formation, paleo-environmental changes through time, its regressive or transgressive trend, and to verify its age.
In the Rencine area the formation lies on the bedrock represented by the Ligurian Unit and it is composed mainly of sandstones and marlstones; pebble conglomerates occur only in the upper part of the sequence. In this area the unit is attributed to the Neogloboquadrina continuosa – Paragloborotalia siakensis Zone (Neogloboquadrina continuosa Subzone) and therefore it is late Serravallian in age.
In the Ponsano area the base of the formation is not outcropping. In constrast, the top below the late Tortonian lacustrine sediments (“Serie lignitifera”), is well exposed. In this area, the outcropping sediments of the unit are attributed to the Neogloboquadrina acostaensis Zone, therefore they are early Tortonian in age. Seven stratigraphic sections were measured and the total thickness of the outcropping sediments is about 500 m. In this area the Ponsano Formation is characterized by two marly units and two sandy units. The sandstones are grey-yellow, medium to fine grained, well cemented and rich in macrofossils and trace fossils of the Skolithos ichnofacies; in the upper sandstone conglomerates occur. The marlstone are composed of massive grey marls and sandy marls.
Benthonic foraminifers are present in all the lithologies. In the Rencine outcrop the most frequent are: Ammonia beccarii, Nonion boueanum, Textularia sagittula, Lobatula lobatula and Elphidium crispum. This assemblage is indicative of the infralittoral zone. The Rencine succession could represent a transgressive trend.
In the Ponsano area, on the basis of foraminifers assemblages, it is possible to subdivide the succession into 4 parts:
A – frequent Ammonia beccari, Nonion boueanum, Textularia sagittula, Ammonia inflata, Nonion commune and Ammomarginulina sp., and common Bigenerina nodosaria, Lagenammina atlantica and Elphidium crispum;
B – abundant Heterolepa bellincionii, Ammonia inflata, Lenticulina calcar, Textularia abbreviata, Valvulinerina bradyana, Hopkinsina bononiensis and common Nonion commune, Spiroplectinella carinata and Haplophragmoides spp.;
C – the same abundant taxa as B, but without Hopkinsina bononiensis (present in only one sample) and with very frequent Uvigerinidae (Hofkeruva rutila and Uvigerina hollicki) and Buliminidae (Bulimina elongata, B. costata, Globobulimina affinis) and common Fondbotia wullestorfi, Pullenia bulloides, Sphaeroidina bulloides. The maximum values of species diversity are recorded in this assemblage;
D – rare Ammonia beccarii, Elphidium crispum, Nonion boueanum, Quniqueloculina sp. and Textularia sagittula.
The qualitative and quantitative foraminiferal data indicate a shelf environment. The first marly unit indicates the circalitoral zone, while sandstones and the second marly unit indicates the infralittoral. Sediments in the upper part of the succession (sandstones and conglomerates) were interpreted as deltaic deposits. The succession of the Ponsano outcrop is a regressive trend. Sedimentation of such a thick succession of marlstones and sandstones in a shelf environment is related to constant tectonic subsidence, while batimetrie fluctuations could be related to eustatic change of the sea level. In particular, the boundary between the upper level of marlstones and sandstones is correlated with the Mi7 event of the isotopic zonation. In contrast, the end of sedimentation could be associated with a decrease in the subsidence rate and/or with an increase in the sedimentation rate related to the uplifting of nearby areas.
- Gentili S., Ambrosetti P. & Argenti P. (1997)
Large carnivore and other mammal fossils from the Early Pleistocene alluvial plain of the Tiberino Basin (Pantalla, Central Italy). Preliminary reports
pp. 231-238
The extensional Plio-Quaternary Tiberino Basin extends from San Sepolcro to Terni (Central Italy) forming an upside-down “Y” shape. The study area is located along the southwestern branch of this “Y” near the village of Pantalla (between Marsciano and Todi). The Tiberino Basin filling is made up of continental deposits, of which the oldest outcropping sediments are deep meromictic lacustrine deposits. An angular unconformity divides these Pliocene lake sediments from horizontal Early Pleistocene alluvial sediments (S. Maria di Ciciliano Formation).
Sandy lithosomes belonging to this Formation are interpreted as high-sinuosity channel fillings while paleosols and pond, wetland and crevasse-splay deposits are identified respectively by silty clays with pedogenetic characteristics, laminated silty clays, lignites, and sandy bodies.
In the stratigraphic succession studied near Pantalla (SMCF) paleosols, crevasse-splay and channel deposits outcrop. Fossil remains have been found within two strata. One, consisting of silty sands and interpreted as crevasse-splay deposits, yields abundant mammalian remains. The mammal assemblage includes a small-medium sized deer (Pseudodama cf. P. nestii), a bovine (Leptobos sp.), a suid (Sus cf S. strozzii), a dog (Canis cf. C. etruscus) and two cats (Lynx cf. L. issiodorensis and Panthera cf. P. gombaszoegensis). Cranial skulls, including those of lynx, panthers and dogs, are abundant in the assemblage.
The other fossil-bearing stratum is a paleosol. The macromammal fauna within this bed are restricted to herbivora, including the bony remains of a horse (Equus sp.), a small-medium sized deer (Pseudodama cf. P. nestii) and a bovine (Leptobos sp.), as well as rare Pseudodama cf. P. nestii teeth. The mandible of a micromammal (Apodemus cf. A. dominans) was also located in this stratum.
Different physical and biological processes have produced these two mammal assemblages and this fauna places it among the richest known Pleistocene faunas of the Tiberino Basin. The assemblage from the Pantalla site may at present be attributed to the Late Villafranchian.
- Laghi G.F. (1997)
Consideration on Nuculoid diversity in che Mediterranean area during che Plio-Pleistocene interval
pp. 239-244
The taxonomic diversity of Nuculoids in the Mediterranean region, from Upper Miocene to the Recent, was reviewed. The analysis shows that two migration events of species, not present in the Mediterranean Miocene, was recorded: some Atlantic species were migrated during the Lower Pliocene, and some boreal species during the Upper Pliocene, in relation to a strong climatic deterioration. The Nuculoids have not been involved by taxonomic changes as a consequence of building, in the Pliocene, of a latitudinal climatic zonation and by the sudden introduction, during the Pleistocene, of the Senegalese hot elements. The decrease in time of the Nuculoid diversity seems not to be directly caused by changes in the shallow and deep water temperature as shown in the Mexico Gulf uniformitarian model. It is possible to interpret this decrease with Sanders stability-time model which seems a good, non catastrophist theory for explain the biological extinction.
- Monegatti P., Raffi S. & Raineri G. (1997)
The Monte Falcone – Rio Riorzo composite section: biostratigraphic and ecobiostratigraphic remarks
pp. 245-260
The ecobiostratigraphic study of the historical Piacenzian stratotype and in particular of the Monte Falcone – Rio Riorzo section supports a three-fold subdivision of the Pliocene, consistent with the introduction of a new stage representing the Upper Pliocene. The base of this new stage, the Gelasian, which was ratified by IUGS in 1996, just predates the onset of significant northern hemisphere glaciation (in the sense of Shackleton et al., 1984 ).
In the M. Falcone – R. Riorzo section two of the more significant changes in the taxonomic diversity of the Mediterranean molluscan fauna are recorded. The older change, characterized by the sharp disappearance of tropical taxa, is well calibrated within the magneto-biostratigraphic framework of the Mediterranean Pliocene and appears just to post-date the very base of the Gelasian. The paleoecological analyses of the succession testify that this change is not due to edaphic factors but to paleoclimatic changes.
In conclusion the Monte Falcone – Rio Riorzo section appears to represent an useful ecobiostratigraphic model for the evolution of the shallow water environments of the Mediterranean late Pliocene.
- Negri A., Pirini C., Razzore S., Bonci M.C., Cirone G., Mancin N. & Viaggi M. (1997)
Micropaleontological record in the Pliocene of Genoa-Arenzano area
pp. 261-274
This paper aims to analyze microfossil assemblages (diatoms, calcareous nannofossils and foraminifers) found in scattered Pliocene outcrops referred to the Argille di Ortovero Formation. The studied samples were collected in two different areas of the Genoa Province (Arenzano and Genoa town-centre) both from geoengineering boreholes and from digs for building foundations.
Biostratigraphically representative species of the different assemblages were recognized; statistic morphofunctional and quantitative analyses were furthermore carried out on benthic and planktic taxa respectively, providing useful data on palaeoenvironmental and palaeoclimatic conditions. The integrated biostratigraphic study allowed to recognize the following Zones: Thalassiosira convexa Zone (subzone C), MNN12 (Amaurolithus tricornicolatus Zone), MPL1 (Sphaeroidinellopsis seminulina Zone, post-acme). The presence of Globorotalia margaritae (MPL2) is furthermore reported from other sections in the same areas.
The present work is part of a more general research on the Pliocene of the western Liguria.
- Bianucci G., Cantalamessa G., Landini W., Ragaini L. & Valleri G. (1997)
Fossil mollusk association from Isabela Island (Galápagos, Ecuador)
pp. 277-281
In this paper a fossiliferous assemblage coming from Puerto Villamil (Isabela, Galápagos) is examined. The sandy sediments chiefly contain a molluscan association besides arthropod pincers, spicules of siliceous sponges, sea urchin spines, barnacle plates, rare foraminifers and abraded fragments of corals and briozoa. The mollusk assemblage represents a subtidal community associated with coral reefs and is dominated by Panamic forms. The modern aspect of this fauna and the radiometric ages till now proposed suggest a Pleistocene age for the Villamil deposits, although the presence of the extinct species Pegophysema spherica, for the first time reported from Isabela, might indicate a Pliocene age.
- Carboni M.G. & Palagi I. (1997)
The Plio-Pleistocene boundary in the significant areas of Northern Latium
pp. 283-292
In this paper three foraminifera assemblages characteristic of the N/Q boundary – in several sites located in Northern Latium – are described.
These assemblages – either in subsurface samples or outcropping – are peculiar to three distinct depositional environments. The infralittoral environment assemblage (Elphidium spp. and Ammonia spp.) is marked by typical species of this environment and dominated by Elphidium crispum and Ammonia beccarii.
The upper circalittoral environment assemblage is dominated by Bulimina genus: Bulimina elegans marginata, Bulimina fusiformis and Bulimina marginata being the most abundant species.
The deeper environment assemblage (Bolivina alata) is characterized by the presence of Globorotalia infiata, and is attributed to the lower circalittoral depositional environment.
- Ciangherotti A.D. (1997)
Paleoecologic and biostratigraphic analysis of the Middle Pliocene land molluscan faunas from the R.D.B. quarry (Villafranca d’Asti, Piedmont, North-West Italy)
pp. 293-301
The section of the R.D.B. quarry, located near Villafranca d’Asti (Villafranchian type-area, Piedmont Basin) is the thickest outcrop (38 m) of the Pliocene S. Martino Unit and its deposits are rich in freshwater and land molluscs. The land molluscan faunas coming from the hydromorphous paleosoils sampled at different levels of the succession have been analysed in order to discover their paleoecologic and biostratigraphic significance.
In each assemblage, hygrophilous land pulmonates are very abundant and associated with some aquatic species, suggesting extremely damp, even swampy environmental conditions. Slight differences in composition and ecologic characteristics among the assemblages – in particular in the percentage of specimens of hygrophilous and aquatic species – could be related to periodic variations in the water table level in these soils. Paleoecological analysis results are in accordance with the fluvial-lacustrine environment of the deltaic plain proposed by sedimentological analyses (Basilici, 1994, 1996). The record of numerous forestal species shows that there was arboreal vegetation in this area. Some species are indicative of a temperate climate, in accordance with plant macrofossil and pollen analyses (Martinetto, 1995; Bertoldi, 1996a, 1996b).
The occurrence of a lot of species typical of the Early Villafranchian of the Piedmont Basin (Triversa Faunal Unit of the mammal biochronology) proves that the R.D.B. succession was deposited during the Middle Pliocene. The Pliocene age is confirmed by some taxa in common with the molluscan faunas from Pliocene sites in Central and Western Europe (Rhine and Rhone Valleys).
Some of the R.D.B. Pliocene land species have also been found in the Dunarobba Fossil Forest deposits (Tiber Basin, Umbria, Central Italy), so that it has been possible to ascribe them to the Pliocene in spite of the lack of vertebrate remains.
- Ciangherotti A.D., Crispino P. & Esu D. (1997)
Paleoecology of the non-marine molluscs of the Pleistocene Stirone River sequence (Emilia, Northern Italy)
pp. 303-310
The Stirone River, a tributary of the Taro River, flows along the boundary between the Parma and Piacenza Districts; along its banks an almost 1000 m thick sedimentary sequence, ranging from the Messinian to the Pleistocene, crops out. Within the Pleistocene succession two main sedimentary cycles can be distinguished: the first (Early Pleistocene) is mostly deposited in a coastal marine environment and intercalated by one continental and two lagoonal episodes; the second (Early Middle Pleistocene) is deposited in a continental environment and separated from the lower beds by an erosional surface. The Early and Middle Pleistocene continental deposits have yielded abundant freshwater and land molluscan faunas, which give good indications as to the paleoenvironmental evolution. They suggest that, within the regressive phase of the long Plio-Pleistocene cycle, the area was characterized by a low-energy fluvial environment, followed, with a gradual transition, by two lagoonal episodes with marine intercalations due to sea ingression and regression respectively. The molluscan assemblage from the first Middle Pleistocene continental level indicates the settlement of a fluvial-lacustrine basin surrounded by grasslands and woods. The woodland gradually extended while water energy and depth decreased to form small water bodies. In accordance with pollen analyses, the aquatic faunas from the two fluvial levels contain some species suggesting warm temperate climate conditions. A lot of the land species found in the upper continental levels are indicative of a temperate climate.
Issue 3
Published in April 1998
- Gnoli M. & Histon K. (1997)
Silurian nautiloid cephalopods from the Carnic Alps: a preliminary investigation
pp. 311-330
Eighteen species of nautiloid cephalopods belonging to thirteen genera are described and illustrated from the Silurian of the Carnic Alps with representative material from the Michelinoceratinae, Kionoceratinae, Leurocycloceratinae, Geisoceratidae, Oncoceratidae and Rutoceratidae respectively. These are compared with the nautiloid faunas from Sardinia and Bohemia. The previous work on the nautiloid fauna from the area is outlined.
- Taviani M., Roveri M., Impiccini R. & Vigliotti L. (1997)
Record of marine Pleistocene deposits in the Chero Valley (Piacenza Province, Northern Apennine, Italy)
pp. 331-338
A previously unreported marine Pleistocene section is documented in the Chero Valley near Bora (Badagnano, Piacenza Province, Northern Italy). The marine sequence is highly fossiliferous, thus allowing a careful reconstruction of the palaeoenvironments. Overall, the marine sequence shows a regressive trend, beginning with muddy-sands deposited in an inner shelf environment, not deeper than 20-40 m and shallowing up to a sandy shoreface setting. Five units have been identified which are from bottom to top: 1) Venus nux clayey sands, 2) Spisula subtruncata – young oysters – phytolites sands, 3) amalgamated sands, 4) mud-sand alternations with shell lags and 5) Chamelea gallina sands. Unit 4 is characterized by storm layers containing a diversified palaeontological content pointing out many diffirent source areas for this material, including Pliocene reservoirs. Due to the shallow paleodepth characterizing the whole section, no planktic index-fossils have been found. We attribute the marine sequence to the early Pleistocene (pre-Emilian) on the ground of the presence of the protobranch Portlandia impressa Perri, 1975 (of supposedly “boreal” affinity), and the lack of both true “northern guests” and Pliocene survivors. Magnetostratigraphic data show that the whole section has a reversal polarity suggesting a tentative attribution to the Matuyama chron. Moreover, physical stratigraphic correlations based on detailed field work show that the unit comprising the Bora section overlays a thick set of units of late Pliocene age, extensively outcropping in the surrounding areas.
- Leone G., Menesini E. & Ragaini L. (1997)
Palaeoecologic and isotopic remarks on a Pleistocene series from Salento (Apulia, Italy)
pp. 339-353
The Pleistocene (Sicilian) sedimentary section outcropping in a quarry near S. Pietro in Lama (Lecce) has been investigated with reference to the molluscan paleocommunities. Samples gathered from three levels have been studied by benthic paleobionomic and stable isotope analyses. The molluscan assemblage of the lower level (L1), composed of silty-sands, contains 75 taxa among which the trophic group of suspension-feeders is prevailing. This assemblage is characterised by the high dominance of mixtophilous species, many of which are characteristic in the biocenoses of the “coastal detritic” (DC) and the “muddy detritic bottoms”(DE). It may be interpreted as an initial stage of the transition facies between DC and DE, located in the upper part of the circalittoral zone. The second level (L2) shows granulometric characteristics similar to those of the previous-one and contains the most abundant and diversified molluscan fauna studied so far (135 taxa), characterised by the predominance of suspension-feeders. From the biocenotic point of view, the mixtophilous and/or DC-DE-species stock is stili prominent whereas the fossil community appears roughly similar to that of L1, a transition facies between DC and DE located in the upper par of the circalittoral zone. However, the significant dominance of VTC stock and the slight increase of deposit-feeders may be related to the increase of the silty component of the sediment and the following decrease of bottom energy. The molluscan assemblages found in L1 and L2 levels may be considered representative of the modern Adriatic “complex muddy sand-detritic biocenosis” (DC-E, sensu Gamulin-Brida, 1974). The highest level (L3) consists of sandy silts containing the poorest molluscan fauna out of the three levels (33 taxa), made up predominantly by detritus-feeders. The bionomic structure of this fossil community differs from the previous levels. The stock of VTC-species becomes dominant, and it is mainly represented by Nucula sulcata, accompanied by a strong decrease in the DC-DE stock. The paleobionomic analysis allows to recognise an originally Nucula–Abra facies of a shallow-water VTC characterised by a soft, but not soupy, bottom, related to a low sedimentation rate. lt may be inferred that the paleobiotope developed at the boundary between the infralittoral and circalittoral zone or in the upper part of the latter.
The carbon and oxygen isotope composition of eight samples belonging to four species of bivalvia (Pseudoamussium septemradiatum, Anodontia fragilis, Plagiocardium papillosum and Chlamys opercularis) and one of gastropoda (Turritella tricarenata pliorecens) was measured. Six samples are from the San Pietro in Lama deposit while two others were collected in the Sicilian sand and clay sediments of a quarry to the south of Cutrofiano, near Lecce. All the measured samples yielded δ18O values between +3.0 and +4.4 ‰ suggesting cold environmental conditions with a marked δ18O enrichment of the Mediterranean water. The data suggest a chronological correlation with the isotopie stage 22 when compared with other isotopic results, particularly with those obtained from foraminifera from Mediterranean cores (Ocean Drilling Program). The shell δ13C is always positive, ranging from +0.1 to +2.6 ‰. Four samples of Anodontia fragilis of two different size show no apparent differences in stable isotope composition.
- Dalla Vecchia F.M. (1997)
New observations on the osteology and taxonomic status of Preondactylus bufferinii Wild, 1984 (Reptilia, Pterosauria)
pp. 355-366
New observations about the osteology and the systematic position of Preondactylus buffarinii Wild 1984b, are based on a reexamination of the holotype (1770MFSN). The carpus and metacarpus of this specimen are described in detail after further preparation. New measurements or the wing metacarpal, first wing phalanx and tibia are presented, allowing new postcranial bone length ratios to be calculated. Similarities of P. buffarinii to Peteinosaurus zambellii are emphasized; its condition of most primitive pterosaur is open to discussion and its diagnosis is emended.
- Fanfani F. & Masini F. (1997)
Insectivores (Mammalia) from Rivoli Veronese, a Late Villanyian site in Northeastern Italy
pp. 367-380
This paper presents a systematic revision of the insectivores from the microvertebrate faunal assemblage recovered at the Rivoli Veronese site, a karst fissure deposit exposed in a limestone quarry near Verona (Northeastern Italy). This revision has enriched our knowledge of the faunal assemblages of the Italian Peninsula, with the first reported occurrences of Sorex bor, Sorex (Drepanosorex) praearaneus and a possibly new species of very small sized mole, Talpa sp.. Also Erinaceus sp., Talpa minor, Petenyia hungarica, Beremendia fissidens and Asoriculus gibberodon have been identified. The correlation of the Rivoli Veronese assemblage with Villanyian assemblages of the bioprovincies of Eastern Europe is confirmed by the presence of Sorex bor and Sorex (Drepanosorex) praearaneus. This species, Asoriculus gibberodon and the two moles may be considered indicative of humid environments with diffuse forest cover.
- Mazza P. (1997)
Taphonomic analysis of late Middle Pleistocene mammal remains from Bucine (Upper Valdarno, Tuscany, Central Italy)
pp. 381-390
The present is a tentative application of a new taphonomic approach proposed by Behrensmeyer (1991), the so-called multivariate pattern, to the renowned mammalian fauna from Bucine (Upper Valdarno, Tuscany, Central Italy). Since the rich fossil collection was assembled during a long period of time, most of the information of the spatial density and arrangement of the specimens is missing; the characteristics of the accumulation are thus deliberately disregarded here. The observations were therefore limited to the assemblage characteristics and to the taphonomic features shown by the fossil assemblage. The obtained results, synthetically presented in graphical form, suggest that the deposit probably formed mostly by attritional processes and was slightly reworked from the original site of accumulation.
- Ferretti M.P. (1997)
Mammuthus cf. primigenius (Proboscidea, Mammalia), a new faunal element from the late middle Pleistocene of the Conca river (Cattolica, Romagna, Italy)
pp. 391-398
Remains of a mammoth from the late middle Pleistocene fluvio-lacustrine deposits outcropping along the flow of the Conca river (Cattolica, Romagna, Italy), are described. The material is referred to M. cf. primigenius, which represents a new element of the Conca fossil mammal fauna, attributed by Conti et al. (1982) to the penultimate cold stage. The morphometric characters of the Conca mammoth do not exclude the possibility it belongs to a more primitive form than typical late Pleistocene M. primigenius.
- Capasso Barbato L. & Gliozzi E. (1997)
Fossil remains of Cervus from the middle Pleistocene-Holocene of the island of Capri (Southern Italy): palaeogeographical implications
pp. 399-406
Several remains of Cervus from Middle Pleistocene to Holocene deposits of the island of Capri are examined. In the upper layers of the Quisisana-Certosa section and at Grotta delle Felci deer remains are referable to the endemic form Cervus elaphus tyrrhenicus Azzaroli, while at Grotta Vascio ‘o funno and Grotta Arcera they are referable to the modern Cervus elaphus Erxleben. These two populations, the first with continental characters and the second showing a clear insular endemism, imply a change in the palaeogeographic setting of the Capri-Penisola Sorrentina district. As the geological data shows undoubtly that Capri was an island since the beginning of Late Pleistocene, the variation of the deer populations can be linked to palaeogeographic variations due only to the Late Pleistocene-Holocene glacio-eustatic oscillations of the sea-level. On the basis of the marine palaeoclimatic curve, on the eustatic curve and on the bathymetry of the area of Bocca Piccola few palaeogeographic charts have been drawn. The Capri Island was connected with the Penisola Sorrentina during Isotopic Stages 6, 4 and 2, was only partially connected during Stage 3 and was completely separated from the mainland during Stage 5 and from 15,000 years B.P. to the present days.
- Boscato P. & Rustioni M. (1997)
Proposed methods of measurements of carpal and tarsal bones in the genus Equus
pp. 407-411
Carpal and tarsal bones of equids are known in some fossiliferous sites and expecially in prehistoric localities. The reference papers used by vertebrate paleontologists and archeozoologists among which the paper published after the “New York International Hipparion Conference, 1981”, are incomplete, because with the exception of the calcaneum and astragalus, the measurements of carpals and other tarsals have been disregarded. For these reasons, the aim of the present paper is to standardize the measurements of the carpal and tarsal bones in the genus Equus.
- Fravega P., Giammarino S., Piazza M. & Vannucci G. (1997)
The rhodolith pavement of the Punta Guitja section, Lampedusa Formation (Upper Miocene -Island of Lampedusa, Pelagian Block). Preliminary note
pp. 413-416
The rhodolith pavement exposed in the middle part of the Punta Guitja section (Cala Pisana Member, Lampedusa Formation, Tortonian – Lower Messinian) is briefly described. Rhodolithic rudstones with bivalves, gastropods and benthic foraminifers form the algal layer. The rhodoliths have sphaeroidal or ellipsoidal shape; the coating sequence is composed of the species Titanoderma cystoseirae, Spongites albanensis, Lithoporella quadratica, Lithothamnion valens, Lithothamnion florea brassica and Lithothamnion iharai.
- Vannucci G., Piazza M. & Fravega P. (1997)
Occurrence of Phymatolithon calcareum (Pallas) Adey & McKibbin in the Late Miocene of Northwestern Italy
pp. 417-419
The present paper deals with the occurrence of the species Phymatolithon calcareum in an algal assemblage recovered from the Late Miocene (Late Tortonian – Messinian) succession of southern Piedmont (NW Italy). This species, known from Oligocene to Recent, is firstly reported in the Late Miocene.