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11.
SCOPIX is a new digital X-ray imaging system for core analysis that uses an X-ray source coupled to a high-energy brightness amplifier and a CCD camera. SCOPIX’s numerical files are images in 256 gray levels equal in value to X-ray densities. Possible data processing approaches include: core logging using grayscale profiles to define the characteristics of sedimentary sequences and image processing to define and quantify lithologic facies and the geometry of physical and biological structures. Applications are: recognition of facies and sedimentary processes, study of sedimentary rhythms and geological cycles, and study of biological and geochemical processes. 相似文献
12.
On the banks of the Garonne River at Bordeaux, the discovery of three antique and medieval harbour platforms situated below the highest spring tide level (HWS) is witnessed to its increase of 1.10 m between the 12th and 14th centuries. It was then identified during excavations in the port of London and along the southern coast of the North Sea. In another direction, European studies suggest the consequences of such a sea level rise by identifying submerged ancient and medieval sites. This increase can be correlated to climatic oscillations, both regional and global, as has been identified by dendroclimatology. This centennial increase has not been accepted as an integral part of the curve expressing the maritime contour line over a period of thousands of years. This latter curve tends to smooth out oscillations in the order of a century and regional scale. To conclude, this medieval increase is comparable to that attested during the 20th century; this permitting a modulation of the importance of the anthropic component on the latter. To cite this article: T. Gé et al., C. R. Geoscience 337 (2005). 相似文献
13.
Morphostructure of the Egyptian Continental Margin: Insights from Swath Bathymetry Surveys 总被引：1，自引：0，他引：1
Jean Mascle Olivier Sardou Lies Loncke Sébastien Migeon Laurent Caméra Virginie Gaullier 《Marine Geophysical Researches》2006,27(1):49-59
In the Eastern Mediterranean, offshore Egypt, the Nile continental margin is characterized by a large deep water turbiditic
system known as the Nile Deep Sea Fan. This post-Miocene terrigenous construction covers an approximately 10 km-thick sedimentary
pile, including 1–3 km of Messinian salt layers. Systematically collected swath bathymetric data proved to be the most powerful
tool to discover, describe and study many sea floor features of this sedimentary construction which reflects competition between
active tectonic, sedimentary, and geochemical processes. Gravity tectonics, triggered by underlying mobile salt layers, construction
of channel-levee systems, the passage of turbidite flows, sedimentary slope failures at various scales, massive mud expulsions
and fluid seepages are all interfering to shape the Nile Deep Sea Fan seabed. 相似文献
14.
Christophe Larroque Bernard Mercier de L��pinay S��bastien Migeon 《Marine Geophysical Researches》2011,32(1-2):163-179
We present here new data from the MALISAR surveys that focus on two areas of the northern Ligurian margin where we reveal recent and active deformation. A set of N60°E scarps that are oblique to the margin is seen at the foot of the continental slope. These correspond to cumulated reverse-strike slip faulting that is consistent with the present-day kinematics of earthquakes. At the north-western margin, the Marcel Fault appears at the surface as a 10-km-long scarp trending N60°E. Several earthquakes of moderate magnitude (3.8 < ML < 4.6) have focal mechanisms consistent with the geometry and the kinematics of, and have been located around, the Marcel Fault. At the north-eastern margin, offshore of Imperia, the major feature is a large promontory that is bound by a network of N60°E faults on its southern side. The structures and the deflection of the drainage network are consistent with a recent uplift of the Imperia Promontory. No surface ruptures have been identified in the epicentre area of the 1887 Ligurian earthquake (the major historical regional event: MW ~6.5?C6.7), although the Imperia Fault network has the necessary characteristics to account for this earthquake. Therefore, from the present study, we propose that the rupture, as a reverse-strike slip faulting of a few or all of the segments belonging to the Imperia Fault network, was the source of the 1887 event. These MALISAR data have allowed identification of an 80-km-long transpressive system of Plio-Quaternary faults. The question of the potential activation of all of these faults during a single event is now of major concern, which has led to reappraisal of the regional seismic hazard as moderate to high. 相似文献
15.
Emmanuelle Ducassou Thierry Mulder Sbastien Migeon Eliane Gonthier Anne Murat Marie Revel Lucilla Capotondi Stefano M. Bernasconi Jean Mascle Sbastien Zaragosi 《Quaternary Research》2008,70(3):382-391
Clastic mud beds rich in continental organic matter are observed recurrently in the Nile deep-sea turbidite system. They formed during flooding periods of the river similar to those that induce sapropel formation and occurred during periods of increased density stratification of the eastern Mediterranean. The very fine-grained flood deposits are intercalated within pelagic sediments, sapropels and Bouma-type turbidites. These flood deposits form by the successive reconcentrations of surface (hypopycnal) plumes by convective sedimentation, which in turn generate a fine-grained low-energy hyperpycnal flow. Sea-level high stands seem also to favor hypopycnal plume formation and increase clastic mud bed formation. Consequently, these muddy clastic beds provide a direct link between deep-marine sedimentary records and continental climatic change through flood frequency and magnitude. 相似文献