1,721,000 research outputs found
Reticulinella kaeveri CHERCHI, RADOIČIĆ & SCHROEDER: a marker for the middle-upper Turonian in the shallow-water carbonate facies of the peri-adriatic area.
No full textReticulinella kaeveri CHERCHI, RADOICˇIC ́ & SCHROEDER is recorded for the first time in the Upper Cretaceous shallow-water carbonates of the southern Apennines. The narrow stratigraphical range and the wide geographical distribution of this species makes it a very valuable biostratigraphic marker in the Turonian of the periadriatic carbonate platforms. Strontium isotope stratigraphy of well preserved rudist shells from levels containing Reticulinella kaeveri, or immediately above its last occurrence, allows the chronostratigraphic age of this species to be defined more precisely. However, owing to the presence of a distinct late Turonian minimum in the marine reference curve, the strontium isotope ratios of the studied samples are compatible both with a late middle Turonian (upper part of the deverianum zone) and with a late Turonian age (neptuni zone)
Comment on "Sea-level control on facies architecture in the Cenomanian-Coniacian Apulian margin (Western Tethys): A record of glacio-eustatic fluctuations during the Cretaceous greenhouse?"
No full textGaleotti et al. (2009; Galeotti S., Rusciadelli G., SprovieriM., Lanci L., Gaudio A., Pekar S., A record of glacio-eustatic
fluctuations during the Cretaceous greenhouse? Palaeogeogr. Palaeoclimatol. Palaeoecol. 276, 196–205) (hereafter
Getal09) use the sequence stratigraphic record of a Cenomanian–Coniacian base-of-slope succession, exposed in
the Morrone mountain of central Italy, to calibrate the sea-level history inferred from the adjacent Lazio-Abruzzi
carbonate platform. The episodes of sea-level fall recorded by this carbonate platform and slope in the western
Tethys are said to coincide with episodes of global cooling and sea-level fall recorded in the New Jersey margin
(Miller, K.G., Sugarman, P.J., Browning, J.V., Kominz,M.A.,Hernández, J.C., Olsson, R.K.,Wright, J.D., Feigenson,M.D.,
Van Sickel, W., 2003. Late Cretaceous chronology of large rapid sea-level changes: glacioeustasy during the
greenhouse world. Geology 31, 585–588). On the basis of this correlation, Getal09 claim that the Late Cretaceous
sea-level history of the Lazio-Abruzzi carbonate platform was controlled by glacio-eustatic fluctuations.
This conclusion conflicts with a wealth of published data supporting the view that the major unconformities in
the Cretaceous carbonate platforms of central-southern Italy were controlled by regional tectonics.
We will show how the sea-level history of the Lazio-Abruzzi carbonate platform proposed by Getal09, and its
correlation with the base-of-slope section, hinge on a misrepresentation of the chronostratigraphic resolution
attainable with biostratigraphy in shallow-water carbonate facies.
We will also show how, contrary towhat claimed by Getal09, the age-model for their base-of-slope section does
not support the correlation with the New Jersey margin sequences. Finally, we will argue that, in Upper
Cretaceous carbonate platforms, the integration of bio- and chemostratigraphy can greatly improve stratigraphic
resolution and chronostratigraphic correlation. This is a prerequisite for using the shallow-water record to test the
hypothesis of global glacio-eustatic fluctuations in the Cretaceous greenhouse
Comment on "Sea-level control on facies architecture in the Cenomanian-Coniacian Apulian margin (Western Tethys): A record of glacio-eustatic fluctuations during the Cretaceous greenhouse?" by S. Galeotti, G. Rusciadelli, M. Sprovieri, L. Lanci, A. Gaudio and S. Pekar [Palaeogeography, Palaeoclimatology, Palaeoecology 276 (2009) 196-205]
No full textGaleotti et al. (2009; Galeotti S., Rusciadelli G., Sprovieri M., Lanci L., Gaudio A., Pekar S., A record of glacio-eustatic fluctuations during the Cretaceous greenhouse? Palaeogeogr. Palaeoclimatol. Palaeoecol. 276, 196-205) (hereafter Getal09) use the sequence stratigraphic record of a Cenomanian-Coniacian base-of-slope succession, exposed in the Morrone mountain of central Italy, to calibrate the sea-level history inferred from the adjacent Lazio-Abruzzi carbonate platform. The episodes of sea-level fall recorded by this carbonate platform and slope in the western Tethys are said to coincide with episodes of global cooling and sea-level fall recorded in the New Jersey margin (Miller, K.G., Sugarman, P.J., Browning, J.V., Kominz, M.A., Hernández, J.C., Olsson, R.K., Wright, J.D., Feigenson, M.D., Van Sickel, W., 2003. Late Cretaceous chronology of large rapid sea-level changes: glacioeustasy during the greenhouse world. Geology 31, 585-588). On the basis of this correlation, Getal09 claim that the Late Cretaceous sea-level history of the Lazio-Abruzzi carbonate platform was controlled by glacio-eustatic fluctuations.This conclusion conflicts with a wealth of published data supporting the view that the major unconformities in the Cretaceous carbonate platforms of central-southern Italy were controlled by regional tectonics.We will show how the sea-level history of the Lazio-Abruzzi carbonate platform proposed by Getal09, and its correlation with the base-of-slope section, hinge on a misrepresentation of the chronostratigraphic resolution attainable with biostratigraphy in shallow-water carbonate facies. We will also show how, contrary to what claimed by Getal09, the age-model for their base-of-slope section does not support the correlation with the New Jersey margin sequences. Finally, we will argue that, in Upper Cretaceous carbonate platforms, the integration of bio- and chemostratigraphy can greatly improve stratigraphic resolution and chronostratigraphic correlation. This is a prerequisite for using the shallow-water record to test the hypothesis of global glacio-eustatic fluctuations in the Cretaceous greenhouse. © 2010 Elsevier B.V
THERMAL MATURITY OF THE SOUTHERN APENNINIC PLATFORM UNIT (SOUTHERN ITALY): CONSTRAINTS FROM ROCK-EVAL PYROLYSIS
No full textStrontium isotope stratigraphy in the upper Cenomanian shallow-water carbonates of southern Apennines: Short-term perturbations of marine 87Sr/86Sr during the oceanic anoxic event 2
No full textStrontium isotope stratigraphy of shallow-water carbonates from the southern Apennines (Italy) indicates that the late Cenomanian−early Turonian evolution of marine 87Sr/86Sr is not accurately depicted by the marine reference curve. Using the low-Mg biotic calcite of well-preserved rudist shells as a study material and carbon isotope stratigraphy for correlation to the standard ammonite biozonal scheme of Northern Europe, new 87Sr/86Sr values are proposed for four different stratigraphic levels: the middle and uppermost part of the guerangeri zone, the lower and upper part of the geslinianum zone. The southern Apennines data suggest that a sharp positive shift at the onset of oceanic anoxic event 2 precedes the well-known Sr isotope negative shift. The positive shift is interpreted in terms of enhanced rates of chemical weathering, driven by global warming forced by volcanogenic CO2 outgassing. A stratified ocean is invoked to reconcile the high gradient and the short lag time of the perturbation with estimates of present-day total mass and residence time of strontium in the ocean. The sharp switch to the negative shift is related to the collapse of water-column density gradient, driven by thermal instability during a late Cenomanian cool event. More active ocean circulation suddenly delivered to surface waters the signal of increased submarine volcanism that had accumulated in deep waters
The evolution of Upper Cretaceous rudist-bearing limestone in the Campania Apennines (Southern Italy) in the light of an integrate bio-chemostratigraphy
No full textStratigraphic setting of a segment from the Eastern margin of the Apennine platform (Monte di Viggiano, Southern Apennines)
No full textIn this study the carbonate succession of the Monte di Viggiano, situated about 30km South of Potenza (Southern Italy), has been investigated in detail for the first time. Three sections have been selected and a high resolution sampling was carried out. Integrated fabric and facies analyses supplemented with biostratigraphic observations have been used to evaluate the depositional environments and ages of the investigated deposits. Palaeontological assessment indicate a deposition within a subtropical inner shallow platform environment. This allow us to associate the limestones to the tectonic unit of Alburno-Cervati that represent the internal realm of the Apennine platform. Palaeontologic analyses give us a Late Liassic age for the lowermost section. The other two profiles show shallow-water limestones evolving from the Valanginian to the Early Cenomanian. This sedimentary record is, however, affected by frequent episodes of breccia sedimentation. At least four brecciation processes could be distinguished throughout this time span. The breccias originated probably from periodic emersion of some parts of the platform due to relative sea-level changes and were deposited in the close vicinity to where they were generated. Miocene quartzarenites have been found for the first time on the Monte di Viggiano, unconformably lying over the Mesozoic deposits. © 2012 Società Geologica Italiana, Roma
The evolution of the earliest representatives of the genus Orbitoides: implications for Late Cretaceous biostratigraphy
No full textThe biostratigraphy of Campanian-Maastrichtian carbonate platforms is largely based on the larger foraminiferal genus Orbitoides. However, while the taxonomy and the chronostratigraphic age of the younger species of this genus are well established, there are still many controversies on the earliest species. We have restudied their morphological characters using a large collection of samples from the type-localities and from continuous sections in the southern Pyrenees. Based on these new observations, the long forgotten species O. sanctae-pelagiae is reinstated, while O. dordoniensis is considered a junior synonym. Successive populations of O. hottingeri, O. sanctae-pelagiae and O. douvillei show gradual morphological changes in time marked by an increase in the size and complexity of the macrospheric embryonal apparatus, an increase of the size of the adult specimens of both generations and the pro- gressive appearance and development of true lateral chamberlets. The Font de les Bagasses Unit in the southern Pyrenees preserves a high-resolution archive of the evolution of the earliest Orbitoides. Strontium isotope stratigraphy indicates that the oldest species, O. hottingeri, made its first appearance in the earliest Campanian, close to the Santonian-Campanian boundary, and was replaced by O. sanctae- pelagiae at a level closely corresponding to the boundary between the Placenticeras bidorsatum and Menabites delawarensis ammonite zones
Thermal maturity of the Southern Apenninic Platform Unit (Southern Italy): constraints from Rock-Eval Pyrolysis Tmax data
No full textA short account on the available data on the thermal evolution of the Mesozoic carbonate apenninic succession
The main steps in the evolution of rudist bearing carbonates in the Campania Apennines (southern Italy): a refined time-framework using chemostratigraphy
No full text- …
