F. Gamberi, G. Valle, M. Marani, A. Mercorella, S. Distefano, A. Stefano
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引用次数: 8
Abstract
Continental margins are often characterised by wide slope sectors with complex topography due to seafloor deformation linked with mobile shale or salt, or local tectonics. Within the resulting slope environments, sedimentary systems can be complex and often structured in variously connected, separate intraslope basins. In this paper, we investigate how the diverse arrangement of sedimentary systems on topographically complex slopes relate to regional differences in extensional tectonic setting. Our study is carried out through the analysis of bathymetric data in the central and southeastern portion of the Tyrrhenian Sea, a back-arc basin that displays wide slope sectors, surrounding the deep Marsili and Vavilov basin plains. A “connected tortuous corridor” forms in the Latium-Campanian slope, where extensional faults are parallel to the margin. Here, tectonic structures are important in controlling the relative extent of dip and strike sectors as well as depositional and erosional segments of submarine drainage networks. Confined, margin-parallel troughs, such as the Capo d’Orlando and the Paola Basins, form respectively landward from volcanic edifices and mud remobilisation ridges. Their depositional setting is mainly the result of the relationships between the basin dip and the site of major sediment input. An unconfined trough parallel to the margin forms when its edge coincides with down-to the basin extensional faults, such as in the case of the Gioia Basin. Its axis is the site of a longitudinal slope valley that shows morphologic variations controlled by tectonic structures. Transverse troughs cutting the entire slope form when tectonic structures are perpendicular to the margin, such as in the Cilento slope. Here, the pattern of extensional faulting is the major control on the degree of connection of successive basins and the eventual development of a drainage system. Throughgoing slope valleys form in graded slope, where sedimentary packages are thick enough to heal the relief associated with tectonic structures. They have planforms, relief and erosional or depositional attitude that is controlled by slope steps connected with faults. As a general outcome, our research provide a valid framework that illustrates the range of possible architectures of sedimentary systems and of their constituents in extensional continental margins.
期刊介绍:
The Italian Journal of Geosciences (born from the merging of the Bollettino della Società Geologica Italiana and the Bollettino del Servizio Geologico d''Italia) provides an international outlet for the publication of high-quality original research contributions in the broad field of the geosciences.
It publishes research papers, special short papers, review papers, discussion-and-replies for their rapid distribution to the international geosciences community.
The journal is firstly intended to call attention to the Italian territory and the adjacent areas for the exceptional role they play in the understanding of geological processes, in the development of modern geology and the Earth sciences in general.
The main focus of the journal is on the geology of Italy and the surrounding sedimentary basins and landmasses, and on their relationships with the Mediterranean geology and geodynamics. Nevertheless, manuscripts on process-oriented and regional studies concerning any other area of the World are also considered for publication.
Papers on structural geology, stratigraphy, sedimentology, basin analysis, paleontology, ecosystems, paleoceanography, paleoclimatology, planetary sciences, geomorphology, volcanology, mineralogy, geochemistry, petrology, geophysics, geodynamics, hydrogeology, geohazards, marine and engineering geology, modelling of geological process, history of geology, the conservation of the geological heritage, and all related applied sciences are welcome.