Abstract
The architecture of sedimentary basin is the result of the interplay
between deep-seated tectonic processes at lithospheric or crustal scale creating or
reducing the accommodation space, and the near-surface processes taking place in
the source and depositional areas. Understanding the evolution of the
sedimentary basin requires, therefore, an integrated study of the coupling
between sediment
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routing and lithospheric processes that are responsible for
basin formation, evolution and, ultimately, for its closure by complete stages of
regressive basin fill, or inversion and exhumation.
This thesis is focused on understanding the mechanism controlling the
tectonic and sedimentary evolution of back-arc basins, from their opening to
subsequent inversion. During the quest of understanding the particular type of
basin formation and subsequent inversion in the Black Sea Basin, two main
objectives were pursued.
The first objective is related to understanding the role played by inherited
extensional rheology in far-field transmission and localization of compressional
deformation driven by an active orogenic area into a pre-existing back-arc domain.
Back-arc contractional geometries are not necessarily controlled by major internal
asymmetries, such as active subduction zones. Therefore, the presence of
inherited rheologically weak zones controls the vergence of thrusting systems
during back-arc inversion. The lateral variability of such weakness zones may
create a contractional polarity change, which is a change in the thrusting vergence
along the strike of the back-arc basin where its opposite margins act as indenters.
This type of change, critical for understanding a number of worldwide basins, such
as the Black Sea or the Huon-Finisterre arc, has received little attention so far in
phenomenological studies.
The second objective of the thesis is to understand the effects of large sea level
variations in the depositional architecture and sedimentary exchange
between basins connected through a shallow marine barrier. The objective is
studied in the context of the Late Miocene-Quaternary sediment fluxes between
the Carpatho-Balkans source area, the Dacian marginal basin and the Black Sea
main sink by the means of seismic sequence stratigraphic analysis calibrated by
wells in both basins.
The thesis is organized in two main sections. Following a brief introduction
in Chapter 1, two observational studies in Chapters 2 and 3 analyze the geometries
and effects of Black Sea Basin back-arc opening and inversion, and the effects of
the large scale sea-level drop recorded during the Messinian Salinity Crisis of the
Paratethys. These observational studies form the base of the phenomenological
process-oriented studies in Chapters 4 and 5 that analyze the mechanisms of backarc
basin inversion by the means of analogue modeling. The thesis ends with the
conclusions of Chapter 6.
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