Quantification des flux sédimentaires et de la subsidence du bassin ...
Quantification des flux sédimentaires et de la subsidence du bassin ...
Quantification des flux sédimentaires et de la subsidence du bassin ...
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tel-00790852, version 1 - 21 Feb 2013<br />
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Subdivisions of the MSC: 1, First phase leading to evaporite <strong>de</strong>position in the peripheral<br />
basins; 2, Second phase (i.e. the peak of the MSC) characterised by a huge sea level drop,<br />
evaporite <strong>de</strong>position in the central basins, and subaerial erosion of the margins.<br />
Subdivisions of the peak of the MSC: step I, d<strong>et</strong>rital <strong>de</strong>position in the central basins after the<br />
huge sea-level drop; step II, step <strong>du</strong>ring which central evaporites were <strong>de</strong>posited and the TRS<br />
<strong>de</strong>veloped; step III, instantaneous catastrophic reflooding.<br />
Figure 4. Uninterpr<strong>et</strong>ed and interpr<strong>et</strong>ed seismic profile across the Gulf of Lions shelf (LRM<br />
28) showing the position of reflectors Mi1 to Mi5 beneath Dm unit. A Serravallian/Tortonian<br />
age for Mi5 leads to a younger age for the <strong>de</strong>position of Dm prisms. Location of seismic<br />
profiles in Fig. 2.<br />
Figure 5. Stratigraphic corre<strong>la</strong>tion b<strong>et</strong>ween Tramontane 1, Calmar 1 and Mistral 1 wells in<br />
the Gulf of Lions shelf. Stratigraphic boundaries and interpr<strong>et</strong>ation of <strong>de</strong>positional<br />
environments come from Cravatte <strong>et</strong> al., (1974) for Tramontane 1 and Mistral 1 and from<br />
Guennoc <strong>et</strong> al., (2000) for Calmar 1. Mi5 intersects the three wells at the exact position (in<br />
Mistral 1) or above (in Tramontane 1 and Calmar 1) an obvious sedimentary boundary (bold<br />
b<strong>la</strong>ck line). In Tramontane 1 and Mistral 1 this boundary, respectively located at 1540 and<br />
1675 m <strong>de</strong>pth, corresponds to a transition from marine to littoral conditions. In Calmar 1, the<br />
boundary is located at 1400 m and corresponds to the Serravallian/Tortonian transition,<br />
leading to a younger age for the <strong>de</strong>position of Dm prisms, which are younger than Mi5.<br />
Figure 6. Uninterpr<strong>et</strong>ed and interpr<strong>et</strong>ed seismic profile (TGS-NOPEC) across the Gulf of<br />
Lions showing the transition from the shelf to the evaporite units. Dm prisms and their distal<br />
counterpart are respectively represented in yellow and blue. The Transgressive Ravinement<br />
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