Mariano Parente

Stepwise extinction of larger foraminifers at the Cenomanian-Turonian boundary: A shallow-water perspective on nutrient fluctuations during Oceanic Anoxic Event 2 (Bonarelli Event)

A two-step pattern in the extinction of larger foraminifers is recorded in the upper Cenomanian shallow-water carbonates of the southern Apennines (Italy). The first step eliminated the alveolinids, the most extreme oligotrophs, and reduced dramatically the diversity of larger foraminifers. The second step wiped out the few survivors, seemingly able to tolerate mesotrophic conditions, leaving a disaster fauna dominated by small heterotrophs. This pattern of extinction parallels the ecological succession of shallow-water benthic foraminiferal assemblages along a gradient of increasing nutrient availability. High-resolution carbon isotope stratigraphy shows that the extinction of alveolinids was contemporaneous with the extinction of rotaliporid planktic foraminifers, the drowning of certain Tethyan carbonate platforms, and an episode of thermal instability recorded in sea-surface temperature in the open ocean. Ocean stratification, during the first phase of Oceanic Anoxic Event 2, would have promoted oligotrophic conditions in surface tropical waters and maximum diversity of larger foraminifers. Following this, ocean overturning caused by surface-water cooling is credited with delivering to shallow-water environments the excess nutrient loads previously stored at depth, triggering the environmental changes leading to stepwise extinction of larger foraminifers.

Carbon-isotope stratigraphy of Cenomanian–Turonian platform carbonates from the southern Apennines (Italy): a chemostratigraphic approach to the problem of correlation between shallow-water and deep-water successions

The carbon-isotope record of three sections of shallow-water carbonates from the Upper Cretaceous sequences of the southern Apennines (Italy) shows a pronounced positive excursion of about 4–5‰. Using the upper Cenomanian Cisalveolina fraasi level as a biostratigraphic tie-point we correlate this excursion to the OAE-2 isotopic event. Comparison with the standard reference δ13C curve of Eastbourne (England) shows that the overall character of the excursion is clearly reproduced in the shallow-water curves. Chemostratigraphic correlation allows definition of the age of some important shallow-water biostratigraphic events to the precision of an ammonite zone, using the well-established bio-chronostratigraphic framework defined in the Eastbourne section. The onset of the Cenomanian–Turonian isotopic excursion coincides with a transgressive trend, recorded by the occurrence of more open-marine facies and culminating with an incipient drowning in one of the sections studied. Our data suggest that the open-ocean isotopic signal is most faithfully recorded and preserved in shallow-water platform carbonates during transgressive periods, when the effects of meteoric diagenesis and seawater ageing are less severe.

STRATIGRAPHIC ARCHITECTURE OF THE SALENTO COAST FROM CAPO D'OTRANTO TO S.MARIA DI LEUCA (APULIA, SOUTHERN ITALY)

The Cretaceous to Quaternary succession of the Apulia Platform cropping out on the eastern coast of the Salento Peninsula shows a special stratigraphic architecture. Whereas on the platform top, i.e. on the Salento Peninsula proper, the succession is at most a few tens of metres thick and is punctuated by unconformities, on the margin and slope of the platform, along the present-day eastern coast of the peninsula, several carbonate systems are laterally disposed and grafted one upon the other. Three of these systems are clinostratified and include well developed reef tracts of Priabonian, early Chattian and early Messinian age. The geologic conclusion of our study is that, since the Late Cretaceous, the eastern coast of the Salento Peninsula grossly coincided with the margin of the Apulia Platform. This paleogeographic element acted as a foreland horst and registered important geodynamic events related to the growth of the adjacent Hellenide and Apennine thrust belts. During the last 60 m.y., the horst carapace was constantly near sea level and sediments were mainly accommodated and preserved on the deep margin and slope of the platform.

Facies and early dolomitization in Upper Albian shallow-water carbonates of the southern Apennines (Italy): paleotectonic and paleoclimatic implications

Thick successions of Cretaceous carbonates in the southern Apennines of Italy are of great economic interest since they host important aquifers and huge hydrocarbon accumulations. The reservoir of the Val d’Agri and Tempa Rossa oilfields (in the subsurface of Basilicata) consists of Upper Cretaceous rudist-rich limestones passing downward into mid-Cretaceous dolomitized limestones of restricted platform facies. Upper Albian-Lower Cenomanian dolomitized carbonates exposed in the Sorrento Peninsula and in the Cilento Promontory, part of the Apennine Carbonate Platform, represent a good surface analogue for the lower part of the reservoir. They are composed of meter-thick beds of stratabound dolomite and shallowing-upward cycles of restricted platform limestones capped by silicified evaporites and marly levels. Field relations, petrography, and geochemistry implicate the reflux of penesaline waters as the most probable dolomitization process. High-frequency climatic variability between dry and wet phases can explain the formation of evaporites, which are coeval with karstic bauxites in other sectors of the southern Apennines. The dolomitized carbonates of the Sorrento Peninsula pass laterally into dolomitized breccias, which were the result of local tectonic collapse of the platform. This is further evidence of mid-Cretaceous syn-sedimentary tectonics that in other areas of the Adria passive margin contributed to the formation of intraplatform basins where source rocks accumulated.

Rhodolith-rich lithofacies of the Porto Badisco Calcarenites(upper Chattian, Salento, southern Italy)

This study describes the rhodolith-rich lithofacies of the Porto Badisco Calcarenites, an upper Chattian rhodalgal/larger foraminiferaldominated unit exposed in the southern part of the Apulia Carbonate Platform (Salento Peninsula, Italy). The lensoid rhodolith-rich lithosome at the base of the studied section is made of rhodolith rudstone and floatstone which infill a channel-like depression inherited from the substrate. Changes in the texture of the rhodolith facies and in the inner structure of the rhodoliths reflect variations in submarine current velocity across the section of the channel. Inherited topography controlled both the locus and the mode of rhodolith accumulation. The rhodolith lithosome is bounded by a flat surface above which rhodoliths are notably absent and beds are tabular. This implies that rhodolith accumulation ended as soon as substrate topography was completely levelled off. The taxonomic composition of the red algal and larger foraminiferal assemblages suggests that the rhodolith-rich unit deposited in the oligophotic zone. The abundance of tropical genera among the coralline algae (Lithoporella and Sporolithon) and the high diversity of larger foraminiferal assemblages indicate that the deposition of the Porto Badisco Calcarenites took place in the warm waters of the tropical to subtropical zone

Dasycladales from the Upper Maastrichtian of Salento Peninsula (Puglia, southern Italy)

SummaryA rich dasycladalean assemblage, mainly consisting of new taxa, has been discovered in upper Maastrichtian coarse bioclastic limestones of shelf margin facies cropping out along the southeastern coast of Salento peninsula (Puglia, Southern Italy).It consists of 8 species grouped into 6 genera:Cymopolia decastroiParente 1994;C. barattoloiParente, 1994;Zittelina fluegeli n.sp;Jodotella koradae (Dieni, Massari & Radoicic, 1983) nov. comb.;Barattoloporella salentina n. gen. n. sp.;Morelletpora dienii n. sp.;Neomeris spp. (two different species). Zittelina fluegeli n. sp. is characterized by an ovoid thallus with calcification made by a calcareous wall enveloping only the proximal part of the branches (except in basal whorls) and by closely packed, and partly coalescent, calcified ampullae arranged all around the median and distal portion of branches.The transferral ofNeomeris (Larvaria) koradaeDieni, Massari & Radoicic, 1983 into the genusJodotella, with the new combinationJodotella koradae, is proposed on the basis of new observations on the number and arrangement of fertile ampullae.The new genusBarattoloporella, type-speciesBarattoloporella salentina n. gen. n. sp., is erected for dasycladalean algae characterized by a segmented thallus. Each segment consists of: a) basal and apical sterile whorls made by primary branches only, b) central fertile whorls made by primary branches bearing in terminal position one fertile ampulla and one or two secondary branches. morelletpora dienii n. sp. is characterized by a segmented thallus with barrel shaped to pear shaped repetitive elements, consisting of simple whorls of first order branches only. Shape of the branches varies from regularly phloiophorous to more or less differentiated in a stalk and a swollen portion, with or without a subterminal constriction.This is by far the most diverse dasycladalean assemblage ever found in the Maastrichtian. Its diversity supports the conclusion that, within the Late Cretaceous, the Maastrichtian represents a maximum in dasycladalean diversity. Its taxonomic composition strenghtens the hypothesis that dasycladaleans were hardly affected by K/T mass extinction.

Geological features, technological characterization and weathering phenomena of the Miocene Bryozoan and Lithothamnion limestones (central-southern Italy)

Bryozoan and Lithothamnion limestones (BLL) from centralsouthern Italy, commercially known as Perlato Royal Coreno, were used for a long time in the monumental architecture of the Campania and Lazio regions. In this paper, new mineralogical-petrographical and engineering geological data about BLL are reported and the relations between the lithofacial and technical features of this stone are investigated. A field survey of the main limestone outcrops allowed a lithostratigraphic reconstruction of this formation to be drawn and the eight main lithotypes presently used as dimension stones to be recognized. Mineralogical and petrographical characterization was performed by means of X-ray powder diffraction and optical microscopy observation of thin sections (under transmitted, UV-reflected light and cold cathodoluminescence). Petrophysical characterization enabled to compare some engineering-geological properties and to evaluate the influences of rock fabric, chemical composition, fractures and stylolithes on the technical features of the stone. Ageing tests were also performed. Finally the main weathering phenomena affecting the stone were recognised through a detailed study on the facades of the bell tower of the Santa Chiara monastery in Naples

Transverse versus longitudinal extension in the foredeep‐peripheral bulge system: Role of Cretaceous structural inheritances during early Miocene extensional faulting in inner central Apennines belt

This study reports on the Rocca di Cave extensional fault system, which is located in the Prenestini Mountains (Central Italy) of the Apennines fold-and-thrust belt and presently represents the oldest exposure of early orogenic foreland fault system of the Apennines. This fault system was oriented perpendicular to the strike of the foredeep-peripheral bulge system, indicating that the onset of convergence was marked by a foredeep-parallel extension, instead of the commonly observed foredeep-perpendicular stretching associated with lithosphere flexuring. The studied fault system is formed by a 10 km long and 2 km wide E-W elongated area that includes two mutually orthogonal sets of faults oriented about E-W and N-S, respectively. E-W and, mainly, N-S striking faults developed during a preorogenic (Santonian to Campanian in age) E-W oriented extension kinematics, which caused first uplift and erosion and then drowning of the Cretaceous carbonate platform and the onset of a pelagic environment. Both fault sets were later reactivated in the early Miocene, when the area was forming part of the foreland region ahead of the eastward migrating Apennines fold-and-thrust belt and was undergoing local N-S oriented, i.e., foredeep-parallel, stretching. This extensional stage implied the sedimentation of hundreds of meters of synkinematic strata in the northern block of the Rocca di Cave Fault System, coevally with episodes of subaerial erosion in areas of the southern block. Further extensional and right-lateral reactivation of inherited faults occurred in the late Miocene, during the progressive incorporation of the area into the Apennines belt.

Dasycladalean green algae from the Upper Triassic of Mt. Rotonda (Verbicaro Unit, Calabria-Lucania Border, Southern Italy)

SummaryA rich and diverse dasycladalean algae association is described from the Upper Triassic succession of Mt. Rotonda (Calabria-Lucania border, Southern Italy).This association consists of:Neoteutloporella rajkae n.sp.,Griphoporella bechstädti n.sp.,Physoporella zamparelliae n.sp.,Spinaporella andalusicaFlügel & Flügel-Kahler, 1984,S.? granadaensisFlügel & Flügel-Kahler, 1984,Chinianella? sp.,Gyroporella sp.,Griphoporella? sp. andPhysoporella aff.leptotheca. Neoteutloporella rajkae n.sp. is characterised by an undulated calcareous skeleton with short acrophore primary laterals bearing a tuft of 4–6 elongate, segmented, trichophore secondary laterals. This species allows to extend back to the Upper Triassic the stratigraphic range of the genusNeoteutloporella, previously known only from Upper Jurassic levels. Griphoporella bechstädti n.sp. has a cylindrical calcareous skeleton and primary laterals only, consisting of a thin proximal part followed by a swollen portion that pinches out distally and finally opens outward with a cup-like swelling. Physoporella zamparelliae n.sp. is characterised by a calcareous skeleton made by partly welded thin individual sheaths enclosing the laterals. The laterals are piriferous, vertically compressed, roughly triangular both in vertical and in verticillar section. In some specimens they end with a spine-like thin apophysis. This species confirms that the typical Middle Triassic genusPhysoporella survived up into the Norian.The dasycladalean algal association of the Norian of Mt. Rotonda shows some similarities with the algal association found in the Upper Triassic of the Betic Cordillera whereas it is markedly different from the rich association occurring in the Upper Triassic of Sicily and of the Northern Calcareous Alps. This pattern is coupled with a different composition of the platform margin communities: microbial/serpulids bioconstructions in the Upper Triassic of the Calabria-Lucania border and of Alpujarridevs. Dachstein-type reefs in Sicily and the Northern Calcareous Alps.This indicates that the palaeoceanographic and palaeogeographic conditions controlled both the development of the different platform margin and of the different algal assemblages.

Heterostegina matteuccii sp. nov. (Foraminiferida: Nummulitidae) from the lower Oligocene of Sicily and Aquitaine: a possible transatlantic immigrant

The systematics and phylogenetic relations of the Oligocene species of Heterostegina (Nummulitidae) are poorly known compared to those of Eocene and Miocene species. The new species Heterostegina matteuccii sp. nov., characterized by the combination of an advanced nepionic stage (i.e. very few operculine chambers) and a relatively small proloculus, is here described from the lower Oligocene Caltavuturo Formation of Portella Colla (Madonie Mts, Sicily, Italy). The same species is recorded also in the ‘Calcaire à astéries’ Formation of Illats (Northern Aquitaine, near Bordeaux, France). Biometrically, H. matteuccii sp. nov. does not fit within any known Neo-Tethyan lineage of Heterostegina from the Eocene to the Miocene, and hence is considered to be a member of a distinct phyletic lineage. The advanced nepionic stage of H. matteuccii sp. nov., however, calls for the existence of predecessors. The Priabonian (and possibly also earliest Oligocene) H. ocalana Cushman, 1921 from the American-Caribbean realm is here interpreted as the most probable ancestral form for the H. matteuccii lineage. Thus, an early Oligocene eastward transatlantic migration of this lineage may be inferred. New results of strontium isotope stratigraphy from both sides of the Atlantic Ocean are consistent with this hypothesis. http://zoobank.org/urn:lsid:zoobank.org:pub:CC54DB64-091D-4CDE-A6AB-6DC620F0FC23