کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4693270 1636852 2011 23 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Bowl-shaped basin related to low-angle detachment during continental extension: The case of the controversial Neogene Siena Basin (central Italy, Northern Apennines)
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Bowl-shaped basin related to low-angle detachment during continental extension: The case of the controversial Neogene Siena Basin (central Italy, Northern Apennines)
چکیده انگلیسی

This paper deals with the tectonic evolution of a bowl-shaped Neogene basin (Siena Basin) located in the inner Northern Apennines and developed during an articulated tectonic evolution. This basin was controversially interpreted by different authors as graben, half-graben or thrust-top basin. Structural and stratigraphic data from the basin substratum and filling sediments, integrated with the interpretation of reflection seismic profiles and borehole logs, highlight that the Siena Basin consists of a tectonic depression with a complex internal architecture. Such a basin developed on a multilayered substratum deeply affected by extensional tectonics since the Middle Miocene. Extensional detachments produced a widespread thinning of the basin substratum and superimposed on contractional structures developed during the Northern Apennines collisional events. Extensional detachments accommodated within weak horizons and gave rise to the lateral segmentation of most competent stratigraphic horizons. Sediments filling the Siena Basin mainly deposited on the Ligurian Units (the topmost tectonic units forming the tectonic pile) in the gap between two laterally segmented geological bodies made up of the Triassic siliciclastic succession of the Verrucano Group. Such a lateral segmentation produced a synformal structural depression, not delimited by faults, filled by Late Serravallian–Late Messinian marine to continental sediments which deposited during the extensional faulting. From the latest Early Pliocene to the Middle Pliocene the architecture of the basin was modified by an high-angle normal fault system which affected the eastern side of the basin and produced new accommodation space for marine sediments. In sum, the Siena Basin consists of a sin-tectonic basin developed on the hanging wall of staircase extensional detachments, later affected by high angle normal to oblique faults. The latter faults defined a half-graben during the latest evolution of the basin. The tectonic evolution of the Siena Basin made it possible to point out some differences with respect to the types of bowl-shaped basins related to extensional detachments and named as supradetachment basins.

Research Highlights
► Characterization of a typology of sin-tectonic bowl-shaped basin related to the extensional tectonics.
► Discussion on the supradetachment versus hangingwall basin-type.
► Discussion on the development of low-angle normal faults in the upper crustal levels.
► Tectonic evolution of the inner Northern Apennines.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Tectonophysics - Volume 499, Issues 1–4, 2 March 2011, Pages 54–76
نویسندگان
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