1,721,003 research outputs found
Il margine settentrionale del Cretacico superiore della Piattaforma Apula (Montagna della Maiella). Escursione n. 2
No full textEscursione Geologica sulla Montagna della Maiella in occasione della 83^ Riunione Estiva, Escursione n. 2., della Società Geologica Italiana tenutasi a Chieti il 15 Settembre 2006. In questa escursione sono stati esposti i caratteri stratigrafici e strutturali principlai del margine orientale della Piattaforma Apula affiorante nella Maiella. Sono stati efettuati diversi stop al fine di illustrare e discutere l'evoluzione stratigrafica del margine durante il Cretaceo.
Il Dr. Morsilli ha curato gli aspetti scientifici insieme ai colleghi dell'Università di Chieti
Event stratigraphy and correlation between two sectors of the Apulia carbonate platform during the Cretaceous (Italy)
No full textMontagna della Maiella: Geometrie ed architettura deposizionale del margine settentrionale della Piattaforma Apula.
No full textGuida alle successioni stratigrafiche della Montagna della Maiella, con descrizione degli stop
2D and 3D reconstruction of an erosional to by-pass margin and related slope deposits of a Cretaceous carbonate platform (Montagna della Maiella, Central Apennines, Italy).
No full textStratigrafia ad eventi: comparazione tra le successioni di scarpata della piattaforma Laziale-Abruzzese e Apula durante il Cretacico
No full textLarge-scale gravity-driven structures: Control on margin architecture and related deposits of a Cretaceous Carbonate Platform (Montagna della Maiella, Central Apennines, Italy)
No full textSpectacular seismic-scale outcrops in the «Montagna della
Maiella» allow to observe directly an average 1000 m high Cretaceous escarpment, abruptly separating shallow-water deposits from slope to basin ones. In plain view, three km-scale amphitheatre-like indentations have been recognized. In section view, along the large scalloped indentations, the escarpment geometry has an exponential profile which changes downslope from high angle (~60°) to sub-horizontal.
Along ridges, between different scallops, the escarpment profile is
more regular, with average angles of 35° and locally steeper (> 45°). We interpret the Maiella escarpment and related morphologies, that are similar in shape and size to those observed in modern scalloped platform margins, as the result of different scale gravity-driven processes occurred during different stages. The larger indentations formed as the result of Albian platform margin collapses, exposing Lower Cretaceous inner platform facies directly to open marine conditions and exporting related products (megabreccias) many kilometres basinward. During the Upper Cretaceous, the inherited physiography controlled the spatial distribution of marginal facies, stratal geometries, basinward exportation of loose sediments
and influenced the stratal stacking patterns in both platform
and slope-basin settings. An overall aggrading margin characterized by the stacking of rudist dominated facies, re-shaped by smaller scale collapses, and a by-pass slope, developed up to the Campanian. At this time, the basin was almost completely filled and the platform started to prograde
The Apulia carbonate platform margin and slope, Late Jurassic to Eocene of the Maiella and Gargano Promontory: physical stratigraphy and architecture.
No full textGeology of the Maiella Mountain and Gargano Promontory. Evolution of the Apulia Carbonate Platform margin during the Cretaceous and Paleogene
The Apulia Carbonate Platform-margin and slope, Late Jurassic to Eocene of the Maiella Mt. and Gargano Promontory: physical stratigraphy and architecture.
No full textGeological field trip - Excursion P18 of the 32 International Geological Congress of Florence. Overview in 4 days about the evolution and stratigraphy of the Apulia Platform Margin in its classical outcropping areas: The Maiella Mountain and Gargano promontory.
University of Ferrara and Chieti components have been organized the field trip in terms of scientific and logistic aspects
2D and 3D reconstruction of an erosional to by-pass margin and related slope deposits of a Cretaceous carbonate platform (Montagna della Maiella, Central Apennines)
No full textCarbonate saturation state vs carbonate production rates in the geological past: in search for a paradigm
No full textSaturation state with respect to carbonate (Ω) plays a crucial role in influencing carbonate precipitation in seawater, which is one of the fundamental processes of the global inorganic carbon cycle. It has been shown that a broad positive correlation exists between modeled variation of Ω in the past and the abundance of carbonates in the geological record. With the goal of investigating further the influence of Ω on the calcification process in the oceans, we have examined several carbonate platforms, with age ranging from the Devonian to the Neogene, and estimated an average carbonate production rate (G, expressed as a mass/unit time/unit surface) for each case study. This task required estimating the volumes of carbonates deposited in selected time intervals, and hence, platforms were chosen for being well age constrained and for the good outcrop conditions. The investigated platforms cover nearly 400 Myr of the geological record and are characterized by significantly different carbonate factories and modes of carbonate precipitation.
We are aware that a number of factors (e.g. the existence of hiatuses) can affect such type of calculations; however, we coped with them by applying some corrections, where possible. For instance, a correction factor was applied to G estimates based on the evidence that the longer the time interval considered, the lower the observed accumulation rates because larger hiatuses are incorporated.
When G estimates for the considered carbonate platforms are plotted in a log/log graph as a function of modeled Ω variations in the geological time (Ridgwell, 2005), they appear aligned and identify a logarithmic relationship. Such relationship closely resembles, and displays similar slope to, the empirical kinetic law that links G and Ω. A significant difference observed, however, is that Gs attained by carbonate platforms are higher than those predicted by the empirical kinetic law.
Results of our investigation suggest that a power law linking G and Ω may govern precipitation in shallow water carbonate systems regardless of the organisms involved and, therefore, Ω could have been the main driver of global calcification in the geological past.
The higher Gs attained by carbonate platforms with respect to those predicted by the empirical G/Ω kinetic law are consistent with laboratory evidence that biologically mediated calcification occurs at higher rates than inorganic precipitation. However, the fact that this is here observed considering ancient carbonate platforms dominated by different organisms, suggests that this biotic effect may be due to mechanisms that could be ecology¬ independent
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