The response of drainage basins to the late Quaternary tectonics in the Sicilian side of the Messina Strait (NE Sicily)

<p>Steep and narrow escarpments develop along the eastern margin of the Korean Peninsula. They are compartments of a passive continental margin and thus have been considered tectonically stable. In contrast to the traditional notion, geomorphic markers indicative of the enhanced tectonic uplift since the Late Quaternary (i.e., coastal terraces at several different altitudes) have been observed along the eastern coastal areas of the peninsula. Therefore, the steep escarpments in the eastern margin are assumed to be tectonically reactivated. However, the spatial magnitude and timing of the reactivation and how the escarpments have responded to the reactivation have not been well studied. Knickzone is a typical geomorphic marker, which has long been utilized for deciphering the history and distribution of tectonics. Here, we examined the knickzones of the marginal escarpments, where transient knickzones are likely to be observed, in order to understand the spatial pattern of the Late Quaternary reactivation and its effects on the evolution of the marginal escarpments. We used SRTM 1 arc-second DEMs, satellite images with fine resolution, and geological maps to identify and classify knickzones. We also conducted field surveys for the verification of the identified knickzones. As a result of the knickzone analysis, 46 knickzones were identified in the study catchments. Their mean length and gradient are 461 m and 0.19 m/m, respectively. Most knickzones are at relatively high altitudes (i.e., median elevation 532 m) and thus are placed far from the coast. According to the classification of the identified knickzones, they are formed mainly due to varying rock types (11) or changes in lithologic features of the same rock type (e.g., weathering degree of rocks) (31). Few of them are associated with the accumulation of coarse sediments at a channel junction (3) and meander neck cut-off (1). This result implies that all identified knickzones in the study catchments are stationary rather than transient. Consequently, it postulates that the Late Quaternary tectonic forcing was insufficient to generate any transient knickzone. Otherwise, potential transient knickzones due to the reactivation might have disappeared rapidly during their upstream migration, which seems highly relevant to the high concavity of the stream profiles in the drainage basins of the escarpments. Additionally, the result suggests that transient knickzone is not a good indicator for interpreting the responses of the marginal escarpments to the reactivation during the Late Quaternary.</p>

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Tectonics and sedimentation of the Lower and Middle Pleistocene mixed siliciclastic/bioclastic sedimentary successions of the Ionian Peloritani Mts (NE Sicily, Southern Italy): the onset of opening of the Messina Strait

Open Geosciences ◽

10.2478/v10085-009-0002-y ◽

2009 ◽

Vol 1 (1) ◽

Cited By ~ 4

Author(s):

Agata Stefano ◽

Sergio Longhitano

Keyword(s):

Tectonic Setting ◽

Fault System ◽

Tectonic Activity ◽

Middle Pleistocene ◽

Central Mediterranean ◽

Coastal Margin ◽

Ne Sicily ◽

Messina Strait ◽

Block Faulting ◽

Tectonics And Sedimentation

AbstractBiostratigraphic analyses carried out on siliciclastic/bioclastic deposits discontinuously cropping out along the Ionian flank of NE Sicily, indicate that they form two sedimentary events of Early and Middle Pleistocene, respec tively. Vertical facies successions, showing transgressive trends, suggest that sedimentation occurred within semi-enclosed marine embayments, where sublittoral coastal wedges developed on steep ramp-type shelves. Sediments accumulated in shoreface to offshore transitions along steep bottom profiles. This depositional scenario was strongly conditioned by the tectonic activity of the rift zone linking Western Calabria and Eastern Sicily. The effects of glacio-eustatism were also recognized. According to our reconstruction, the study area was controlled by a transfer fault system which affected the coastal margin producing major episodes of uplift and subsidence. Block-faulting was responsible for significant cannibalization and recycling of older deposits during the Middle Pleistocene. Such a tectonic setting can be considered the precursor scenario for the formation of the Messina Strait between Calabria and Sicily. This narrow, linear basin influences the hydrodynamic setting of sublittoral deposits along the Ionian coast of Sicily, giving rise to strong flood/ebb tidal currents. The uppermost part of the Middle Pleistocene succession recognized in the study area is indeed dominated by tide-influenced associations of sedimentary structures which most likely record the first stage of the opening of this ‘seaway’ of the central Mediterranean Sea.

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