Download Consulta: creatorFacets:"Mascle, Jean" Registros recuperados: 28

Consulta: creatorFacets:"Mascle, Jean"
Registros recuperados: 28
Data/hora: 09/06/2017 08:43:35
Distribution and geological control of mud volcanoes and other fluid/free gas seepage features in the
Mediterranean Sea and nearby Gulf of Cadiz
Provedor de dados: 5
Autores: Mascle, Jean; Mary, Flore; Praeg, Daniel; Brosolo, Laetitia; Camera, Laurent; Ceramicola, Silvia; Dupre, Stephanie.
Existing knowledge on the distribution of mud volcanoes (MVs) and other significant fluid/free gas-venting features (mud cones,
mud pies, mud-brine pools, mud carbonate cones, gas chimneys and, in some cases, pockmark fields) discovered on the seafloor
of the Mediterranean Sea and in the nearby Gulf of Cadiz has been compiled using regional geophysical information (including
multibeam coverage of most deepwater areas). The resulting dataset comprises both features proven from geological sampling, or
in situ observations, and many previously unrecognized MVs inferred from geophysical evidence. The synthesis reveals that MVs
clearly have non-random distributions that correspond to two main geodynamic settings: (1) the vast majority occur along the
various...
Tipo: Text
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00185/29644/28073.pdf
Description géologique de la bordure provençale
Provedor de dados: 5
Autores: Olivet, Jean-louis; Auzende, Jean-marie; Mascle, Jean; Monti, S.; Pastouret, Léo; Pautot, Guy.
Recent data on the western Mediterranean basin (Joides cruise, Montadert et al., 1970, Auzende et al., 1971, Le Borgne et al.,
1971) and its connection with the evolution of the Atlantic area (Le Pichon et al., 1970, Talwani et al., 1971, Le Pichon et al. in
writing) lead us, like other authors (Dubourdieu, 1962, Stanley and Mutti, 1968, Ryan, 1969 amongst others) to admit the theory
of an opening of the Algero-provencal basin during the Cenozoic era. A series of arguments drove us to formulate the hypothesis
of an Oligocene age (in process). This work is in line with this perspective. [...]
Tipo: Text
Palavras-chave: Histoire Ifremer.
Ano: 1971
URL: http://archimer.ifremer.fr/doc/1971/publication-4907.pdf
Nature de la pente continentale au Sud du Cap des Trois Pointes (Ghana, Afrique)
Provedor de dados: 5
Autores: Mascle, Jean; Smit, Albert F.j.
Ferruginous sandstones and slightly metamorphosed sandstones have been dredged on the continental slope off the Ghanaian
coast at depths of 3 500 to 2 000 m. Their attribution to the Paleozoic series known on dry land is not quite obvious, though some
lithologic affinities exist. As a consequence, the continental slope in this area, which corresponds to the structural continuation of
the Romanche fracture zone, is partially of sedimentary nature.
Tipo: Text
Palavras-chave: Histoire Ifremer.
Ano: 1974
URL: http://archimer.ifremer.fr/doc/1974/publication-5442.pdf
Échantillons rocheux provenant de « volcans de boue » de Méditerranée orientale
Provedor de dados: 5
Autores: Huguen, Caroline; Benkhelil, J; Giresse, P; Mascle, Jean; Muller, C; Woodside, John; Zitter, T; Charlou, Jean-luc.
In the eastern Mediterranean, numerous argilo-kinetic manifestations, commonly named 'mud volcanoes', have been identified and
studied in some detail during the last twenty years using several techniques. The Medinaut survey (December 1998) has provided
new insights into this phenomenon through twenty deep dives performed with the submersible Nautile within two areas
particularly active in terms of mud expulsions: the central Mediterranean ridge south of Crete, and the Anaximander mountains
area, south of Turkey. The morphology, petrography, microstructure and biostratigraphy of different clasts sampled in the two
areas helped to better understand the mud volcano formation and subsequent evolution. Paleoenvironmental conditions, ranging
from deep marine...
Tipo: Text
Palavras-chave: Clasts; Eastern Mediterranean; Deep dives; 'mud volcanoes'.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/00068/17931/15469.pdf
New pole for early opening of South Atlantic
Provedor de dados: 5
Autores: Mascle, Jean; Sibuet, Jean-claude.
USING the trends of equatorial, marginal fracture ridges, Le Pichon and Hayes proposed an early phase for the opening of the
South Atlantic, with a pole of rotation at 21.5°N, 14°W with respect to Africa. Francheteau and Le Pichon2 tested this plate
tectonic model with the whole South Atlantic and assumed that there is a relationship between continental margin offsets, the
subsidence of coastal basins, and adjacent marginal fracture zones. We have studied extensions of fracture zones in the Gulf of
Guinea and adjacent continental margins and have determined a new early opening pole that differs markedly from the one
previously determined. [NOT CONTROLLED OCR]
Tipo: Text
Palavras-chave: Histoire Ifremer.
Ano: 1974
URL: http://archimer.ifremer.fr/doc/1974/publication-5441.pdf
Les structures diapiriques du delta du Niger
Provedor de dados: 5
Autores: Mascle, Jean.
Marine geophysical profiles off Niger Delta reveal the presence of diapiric structures beneath the continental margin. The
hypothesis of a possible evaporitic layer is presented and discussed ; the general structure of the area is briefly compared to the
structure of the northern margin of the gulf of Mexico where well-known evaporitic structures occur along the whole margin.
[NOT CONTROLLED OCR]
Tipo: Text
Palavras-chave: Histoire Ifremer.
Ano: 1975
URL: http://archimer.ifremer.fr/doc/1975/publication-4984.pdf
Structure de la marge continentale norvégienne au débouché de la mer de Barentz
Provedor de dados: 5
Autores: Briseid, E.; Mascle, Jean.
Reconstructions of the continents prior to the opening of the Norwegian sea indicate an overlap between the Greenland and the
Norwegian continental margins just west of the Barentz sea and imply that the basement of this area is of oceanic origin. Seismic
profiling shows an oceanic-type basement covered by thick Tertiary sediments. The sedimentary supply is related to the
geological history of the Barentz sea where only little unconsolidated sediments are known. Further south the structures of the
present margin are directly related to the early opening of the Norwegian sea. [NOT CONTROLLED OCR]
Tipo: Text
Palavras-chave: Histoire Ifremer.
Ano: 1975
URL: http://archimer.ifremer.fr/doc/1975/publication-5440.pdf
Fluid seepage in relation to seabed deformation on the central Nile Deep-Sea Fan, part 2: evidence
from multibeam and sidescan imagery
Provedor de dados: 5
Autores: Praeg, Daniel; Ketzer, Joao Marcelo; Augustin, Adolfo Herbert; Migeon, Sebastien; Ceramicola, Silvia; Dano,
Alexandre; Ducassou, Emmanuelle; Dupre, Stephanie; Mascle, Jean; Rodrigues, Luiz Frederico.
On the central Nile deep-sea fan, stratified sediments overlying mass-transport deposits (MTDs) are deformed into slope-parallel
seabed undulations associated with fluid seepage. The western part of this system, in water depths of 1,950–2,250 m, is examined
using multi-frequency data from hull-mounted and deep-towed swath/profiling systems. Sub-bottom profiles show sub-vertical
fluid pipes that terminate both at and below seabed, and gas signatures along fault planes bounding the undulations. Fluid seepage
is recorded by high- to intermediate-backscatter patches (HBPs, IBPs) that differ in appearance on multibeam imagery (30 kHz,
≤3 m penetration) and sidescan swaths (170/190 kHz, <0.1 m penetration). Comparison of the two suggests a distinction of
(a)...
Tipo: Text
Palavras-chave: Slope undulations; Fluid seeps; Backscatter; Carbonates; Pipes; Faults.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00158/26956/25251.pdf
Structures géologiques de la marge continentale à l'ouest du spitzberg
Provedor de dados: 5
Autores: Malod, J.; Mascle, Jean.
The main structural features of the continental margin off West Spitzberg are outlined. Seaward the Atka ridge has acted like a
dam for the eastward-flowing sediments and thus helped to build up a large sedimentary basin, narrowing towards the North.
Magnetic and seismic data show that the Atka Valley is probably an active accretion rift valley. These results are in good
agreement with the last hypothesis on the opening of the Norwegian Sea. During the Pliocene, a tectonic event may have affected
Atka ridge and modified the subsequent sedimentation. [NOT CONTROLLED OCR]
Tipo: Text
Palavras-chave: Histoire Ifremer.
Ano: 1975
URL: http://archimer.ifremer.fr/doc/1975/publication-5439.pdf
Multi-scale seafloor mapping of active seep-related structures, offshore Egypt
Provedor de dados: 5
Autores: Dupre, Stéphanie; Woodside, John; Klaucke, Ingo; Mascle, Jean; Foucher, Jean-paul.
The Nile deep sea fan system presents a rich variety of fluid escape structures, gas chimneys, pockmarks and carbonate crust
mounds, brines pools, and several types of mud volcano. These seep-related structures were explored for the first time with the
Nautile submersible during the 2003 Nautinil expedition and are characterized by high thermal gradients and highly gas-saturated
sediments. More recently, high resolution side scan sonar data acquired during the 2004 Mimes expedition brings more detail to
the geophysical imagery. The EdgeTech DTS-1 deep tow sonar coupled with a 2-8 kHz chirp subbottom penetrator was deployed
around 100 m above the seafloor and operated at a frequency of 75 kHz. Several gas plumes were acoustically detected in the
water...
Tipo: Text
Palavras-chave: Free gas emission; Backscatter; Authigenic carbonate crust; Mud volcanism; Gas chimneys; Nile Deep Sea Fan.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2005/acte-6396.pdf
Diapiric structures off niger delta
Provedor de dados: 5
Autores: Mascle, Jean; Bornhold, Brian D.; Renard, Vincent.
Several marine geophysical profiles off the southern part of the Niger delta reveal the presence of diapiric structures beneath the
continental slope and rise. The origin of the diapiric material appears to be deep in the sedimentary section and is believed to be of
Aptian-Albian age. If this hypothesis is correct, the presence of evaporite basins, known between angola and Gabon, can be
extended as far north as the Niger delta. [NOT CONTROLLED OCR]
Tipo: Text
Palavras-chave: Histoire Ifremer.
Ano: 1973
URL: http://archimer.ifremer.fr/doc/1973/publication-5119.pdf
AUV surveys cold seep sites on the Nile fan
Provedor de dados: 5
Autores: Boetius, Antje; Buffet, G; Mascle, Jean; Dupre, Stephanie; Foucher, Jean-paul.
Tipo: Text
Ano: 2007
URL: http://archimer.ifremer.fr/doc/00185/29669/28041.pdf
Microbial methane oxidation and sulfate reduction at cold seeps of the deep Eastern Mediterranean
Sea
Provedor de dados: 5
Autores: Omoregie, Enoma O.; Niemann, Helge; Mastalerz, Vincent; De Lange, Gert J.; Stadnitskaia, Alina; Mascle, Jean;
Foucher, Jean-paul; Boetius, Antje.
The Eastern Mediterranean hosts a variety of active cold seep systems, such as gas chimneys, mud volcanoes and pockmarks, in
water depths of 500 to 3200 m. As part of the NAUTINIL expedition in 2003, the sediments of cold seeps on the Nile Deep Sea
Fan (NDSF) were sampled for the first time for biogeochemical and microbiological analyses. Here we compare rates of the
anaerobic oxidation of methane (AOM) and sulfate reduction (SR) as well as the microbial community structure of a variety of
cold seep systems including mud volcanoes, pockmarks and brine seeps. Our results revealed strong differences in microbial
activity among the different seep systems of the Eastern, Central and Western provinces of the NDSF, as well as the Olimpi field
(Central...
Tipo: Text
Palavras-chave: Methane oxidation; Sulfate reduction; Archaea; Cold seeps; Mud volcano; Pockmarks; Nile Deep Sea Fan.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00000/11087/7910.pdf
Warm brine lakes in craters of active mud volcanoes, Menes caldera off NW Egypt: evidence for
deep-rooted thermogenic processes
Provedor de dados: 5
Autores: Dupre, Stephanie; Mascle, Jean; Foucher, Jean-paul; Harmegnies, Francois; Woodside, John; Pierre, Catherine.
The Menes caldera is a fault-controlled depression (~8 km in diameter) at ~3,000 m water depth in the western province of the
Nile deep-sea fan off NW Egypt, comprising seven mud volcanoes (MVs) of which two are active. Based on multichannel and
chirp seismic data, temperature profiles, and high-resolution bathymetric data collected during the 2000 Fanil, 2004 Mimes and
2007 Medeco2 expeditions, the present study investigates factors controlling MV morphology, the geometry of feeder channels,
and the origin of emitted fluids. The active Cheops and Chephren MVs are 1,500 m wide with subcircular craters at their summits,
about 250 m in diameter, generally a few tens of metres deep, and filled with methane-rich muddy brines with temperatures
reaching 42 °C...
Tipo: Text
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00185/29668/28151.pdf
Geophysical study of the easternmost walvis ridge, south atlantic : morphololy and shallow structure
Provedor de dados: 5
Autores: Goslin, J.; Mascle, Jean; Sibuet, Jean-claude; Hosking, H.
The landward termination of Walvis Ridge consists of two east-trending basement ridges of probable basaltic composition
enclosing a relatively important sedimentary basin. East of long. 10° E., the southern ridge disappears under the sediments of the
continental margin. The trends of the basement ridges are in good agreement with the inferred direction of initial opening. Since
its formation, the Walvis Ridge has probably dammed sediment coming from the south. The proposed identification of layer A, a
very strong horizon over which the reflectors are nearly undisturbed, may indicate that no major tectonic phase has affected this
area since the shift of the pole of opening for the south Atlantic in Late Cretaceous-early Tertiary time. [NOT CONTROLLED
OCR]
Tipo: Text
Palavras-chave: Histoire Ifremer.
Ano: 1974
URL: http://archimer.ifremer.fr/doc/1974/publication-5147.pdf
MEDECO Leg 2 cruise report. R/V Pourquoi pas ? 02 to 30 November 2007 Rhodes-Toulon
Provedor de dados: 5
Autores: Pierre, Catherine; Mascle, Jean; Dupre, Stephanie.
The MEDECO Leg 2 cruise followed the MEDECO Leg 1 cruise that had crossed the Mediterranean Sea from the west to the east
to study benthic communities of the Var canyon, deep corals found on the Calabrian Margin and cold seep ecosystems of the
Mediterranean Ridge. The main objective of the MEDECO Leg 2 cruise was to study and compare, using a multidisciplinary
approach, the structure and dynamics of deep-sea ecosystems at various active cold seep sites from the Nile deep sea fan and the
Calabrian Arc, in the Eastern Mediterranean sea. During MEDECO Legs 1 & 2, a multiscale strategy was promoted to
integrate (1) a high resolution cartography of geological structures (km2 scale), (2) a detailed mapping, including video imagery,
of smaller-scale areas...
Tipo: Text
Ano: 2008
URL: http://archimer.ifremer.fr/doc/00134/24550/22583.pdf
Structure and Drivers of Cold Seep Ecosystems
Provedor de dados: 5
Autores: Foucher, Jean-paul; Westbrook, Graham K.; Boetius, Antje; Ceramicola, Silvia; Dupre, Stephanie; Mascle, Jean;
Mienert, Jurgen; Pfannkuche, Olaf; Pierre, Catherine; Praeg, Daniel.
Submarine hydrocarbon seeps are geologically driven "hotspots" of increased biological activity on the seabed. As part of the
HERMES project, several sites of natural hydrocarbon seepage in the European seas were investigated in detail, including mud
volcanoes and pockmarks, in study areas extending from the Nordic margin, to the Gulf of Cadiz, to the Mediterranean and Black
seas. High-resolution seabed maps and the main properties of key seep sites are presented here. Individual seeps show ecosystem
zonation related to the strength of the methane flux and distinct biogeochemical processes in surface sediments. A feature
common to many seeps is the formation of authigenic carbonate constructions. These constructions exhibit various morphologies
ranging...
Tipo: Text
Palavras-chave: Mosby mud volcano; Deep sea fan; Eastern mediterranean sea; Black sea; Anaerobic oxidation; Hydrocarbon
seeps; Carbonate crusts; Sidescan sonar; Hydrate ridge; Gas chimneys.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6387.pdf
Widespread active seepage activity on the Nile Deep Sea Fan (offshore Egypt) revealed by
high-definition geophysical imagery
Provedor de dados: 5
Autores: Dupre, Stephanie; Woodside, John; Klaucke, Ingo; Mascle, Jean; Foucher, Jean-paul.
Fluid escape structures on the Nile Deep Sea Fan were investigated during the MEDIFLUX MIMES expedition in 2004. Mud
volcanoes, pockmarks and authigenic carbonate structures were surveyed for the first time with a high-resolution deep-towed 75
kHz sidescan sonar and a 2-8 kHz Chirp sediment echosounder. In combination with existing multibeam bathymetry and detailed
seafloor in situ geological observations, these new data allowed detailed seep analyses. About 60 gas flares were detected
acoustically in the water column from the sidescan sonar raw data at water depths from 770 to 1700 m. These gas flares coincide
at the seabed with 1) the centres of the mud volcanoes where mud is also extruded, 2) the borders of the mud volcanoes where the
emitted gases...
Tipo: Text
Palavras-chave: Nile Deep Sea Fan; Seepage; Backscatter; Sidescan sonar; High-resolution; Gas chimneys; Mud volcanoes;
Authigenic carbonates.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00013/12457/9766.pdf
Géologie sous-marine du canyon de Toulon
Provedor de dados: 5
Autores: Mascle, Jean.
In a previous article published in the "cahiers Océanographiques" XXII, 1 (January 1970), pp. 25-32, I described the broad lines of
subactual sedimentation in and around the canyon of Toulon. This data had been collected during a drilling cruise conducted in
October 1967. Out of the 41 successful drillings, 17 had enabled the collection of rock samples representing, either the Maures
basement in which the canyon of Toulon is cut, or more recent deposits, episodes of the eustatic or tectonic variations of the water
level over the Quaternary and maybe the Pliocene era.
Tipo: Text
Palavras-chave: Histoire Ifremer.
Ano: 1971
URL: http://archimer.ifremer.fr/doc/1971/publication-4890.pdf
Sismique réflexion oblique dans le fossé de Rockall
Provedor de dados: 5
Autores: Sichler, Bertrand; Mascle, Jean; Cressard, Alain.
La comparaison d'un profil de sismique réflexion oblique avec les résultats d'Une station de sismique réfraction effectuée
antérieurement permet de préciser l'extension probable de la faille « JeanCharcOt » vers le Nord-Est du fossé de Rockall.
Tipo: Text
Ano: 1972
URL: http://archimer.ifremer.fr/doc/00318/42966/42472.pdf
Atlantic-type continental margins:distinction of two basic structural types
Provedor de dados: 5
Autores: Mascle, Jean.
Large areas of the Atlantic ocean continental margin do not fit with the classic atlantic type continental margin model in which
only simple geometrical arrangements have been distinguished. A new structural type, related to marginal offsets and
corresponding fracture ridges is fundamentally different from the classic margin. Consequently, it is proposed to distinguish the
rifted atlantic-type margin, the pacific-type margin and the transform faulted or strike-slip margin as three different and
fundamental types of continental margins. [NOT CONTROLLED OCR]
Tipo: Text
Palavras-chave: Histoire Ifremer.
Ano: 1976
URL: http://archimer.ifremer.fr/doc/1976/publication-4987.pdf
The marginal SaoPaulo plateau, comparaison with the southern angolan margin
Provedor de dados: 5
Autores: Mascle, Jean; Renard, Vincent.
During the Geobrésil cruise of the R. V. Jean Charcot (1973) several marine geophysical lines, including bathymetry, magnetism,
continuous seismic as well as sonobuoy profiles have been run across a deep marginal plateau extending on the southeastern
Brazilian margin and known as the Sao Paulo Plateau. These data indicate the presence of a thick sedimentary cover (more than 4s
DTT) on the upper slope and up to 3s DTT thick on the lower slope and rise. The entire slope is highly disturbed by salt diapiric
structures mostly apparent between the 2 000-3 000 bathymetriclines and comparable to the ones described in the western
Mediterranean sea. The Sao Paulo scarp, bordering the deep marginal plateau to the South-West, is believed to be a discontinuous
and "en...
Tipo: Text
Palavras-chave: Histoire Ifremer.
Ano: 1976
URL: http://archimer.ifremer.fr/doc/1976/publication-4990.pdf
Fluid Seepage in Relation to Seabed Deformation on the Central Nile Deep-Sea Fan, Part 1: Evidence
from Sidescan Sonar Data
Provedor de dados: 5
Autores: Dano, Alexandre; Praeg, Daniel; Migeon, Sebastien; Augustin, Jean-marie; Ceramicola, Silvia; Ketzer, Joao Marcelo;
Augustin, Adolfo Herbert; Ducassou, Emmanuelle; Mascle, Jean.
The central Nile Deep-Sea Fan contains a broad area of seabed destabilisation in association with fluid seepage: slope-parallel
sediment undulations are associated with multibeam high-backscatter patches (HBPs) related to authigenic carbonates. During the
2011 APINIL campaign, a deep-towed sidescan and profiling system (SAR) was used to acquire high-resolution data along three
transects across water depths of 1,700-2,650 m. Three seabed domains are distinguished, all developed within stratified sediments
overlying mass-transport deposits (MTDs). Upslope of the undulations (<1,950 m), sidescan HBPs record focused fluid seepage
via seabed cracks. In the western area of undulations, sidescan HBPs are distinct from intermediate-backscatter patches (IBPs)...
Tipo: Text
Palavras-chave: Fluid seepage; Sediment deformation; Backscatter; Gas flares.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00226/33752/37059.pdf
Formation of carbonate chimneys in the Mediterranean Sea linked to deep-water oxygen depletion
Provedor de dados: 5
Autores: Bayon, Germain; Dupre, Stephanie; Ponzevera, Emmanuel; Etoubleau, Joel; Cheron, Sandrine; Pierre, Catherine;
Mascle, Jean; Boetius, Antje; De Lange, Gert J.
Marine sediments at ocean margins vent substantial amounts of methane(1,2). Microbial oxidation of the methane released can
trigger the precipitation of carbonate within sediments and support a broad diversity of seafloor ecosystems(3,4). The factors
controlling microbial activity and carbonate precipitation associated with the seepage of submarine fluid over geological time
remain poorly constrained. Here, we characterize the petrology and geochemistry of rocks sampled from metre-size build-ups of
methane-derived carbonate chimneys located at the Amon mud volcano on the Nile deep-sea fan. We find that these carbonates
comprise porous structures composed of aggregated spherules of aragonite, and closely resemble microbial carbonate reefs
forming at present...
Tipo: Text
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00156/26734/24854.pdf
Les marges continentales transformantes ouest - africaines : Guinée, Côte d'Ivoire, Ghana et la zone
de la fracture de la Romanche. Campagne Equamarge II : rapport scientifique
Provedor de dados: 5
Autores: Mascle, Jean; Auroux, C.
During the Equamarge II cruise (February 4 to March 21, 1988), on board the R. V. "Jean Charcot", 12.500 kms of continuous
geophysical profiling have been recorded along three sectors of the Equatorial Atlantic. Two segments of the West African
transform margin have been intensively surveyed off Guinea and off Ivory Coast and Ghana. The active Romanche fracture zone
has been surveyed in details on a distance of about 100 kms. These data (multibeam bathymetry, continuous seismic profiling,
magnetism and gravity) have been supplemented by 16 geological stations (dredging and coring). This report gives a synthetic
review of the onboard analysis and allows to better understand the geological structures of the three surveyed areas. [NOT
CONTROLLED OCR]
Tipo: Text
Palavras-chave: Atlantique équatorial; Ouest Afrique; Bathymétrie
sismique réflexion; Zone de fracture océanique; Marges
continentales transformantes.
Ano: 1989
URL: http://archimer.ifremer.fr/doc/1989/rapport-4461.pdf
Submarine Niger Delta: Structural Framework
Provedor de dados: 5
Autores: Mascle, Jean.
Numerous data obtained during recent marine geophysical surveys have been compiled together in order to present the structural
framework of Niger Delta and adjacent areas. Seismic reflection results show that the delta slope is characterized by intense
diapiric deformations and that the overall structure of the delta is fairly comparable to the structures of the Gulf Coast province
margin or of Angolan margin. Seismics as well as gravity and magnetic measurements indicate the existence in the vicinity of the
Niger delta of two oceanic trends apparently related to an early phase of opening of the South Atlantic. Both trends can tentatively
be correlated on land with the major structures known in the southern and northern Benue trough. A comparion between...
Tipo: Text
Palavras-chave: Histoire Ifremer.
Ano: 1976
URL: http://archimer.ifremer.fr/doc/1976/publication-5171.pdf
Structures sous-marines des bassins sédimentaires de Porcupine et de Rockall
Provedor de dados: 5
Autores: Le Pichon, Xavier; Cressard, Alain; Mascle, Jean; Pautot, Guy; Sichler, Bertrand.
In 1921 the "Pourquoi pas?" undertook, under the authority of J. Charcot, an identification of the Rockall bank (2). The
petrographic nature of this relief was studied by Lacroix (2) who concluded to aegirine granite dated, since then, by Miller (3) and
Sabine (4), from the early Tertiary period. At the beginning of the Noratlante cruise, in August 1969, the "J. Charcot" carried out a
number of profiles, tallying the Porcupine and the Rockall area (fig.1). In addition to the gravimetry and magnetism recordings, an
oblique-reflection profile and six Flexotir seismic-reflection profiles (with a frequency comprised of between 10 and 30 cycles)
were carried out. We only present here the first results based on this last technique.
Tipo: Text
Palavras-chave: Histoire Ifremer.
Ano: 1970
URL: http://archimer.ifremer.fr/doc/1970/publication-4873.pdf
Authigenic carbonates related to active seepage of methane-rich hot brines at the Cheops mud
volcano, Menes caldera (Nile deep-sea fan, eastern Mediterranean Sea)
Provedor de dados: 5
Autores: Pierre, Catherine; Bayon, Germain; Blanc-valleron, Marie-madeleine; Mascle, Jean; Dupre, Stephanie.
On the passive margin of the Nile deep-sea fan, the active Cheops mud volcano (MV; ca. 1,500 m diameter, ~20–30 m above
seafloor, 3,010–3,020 m water depth) comprises a crater lake with hot (up to ca. 42 °C) methane-rich muddy brines in places
overflowing down the MV flanks. During the Medeco2 cruise in fall 2007, ROV dives enabled detailed sampling of the brine
fluid, bottom lake sediments at ca. 450 m lake depth, sub-surface sediments from the MV flanks, and carbonate crusts at the MV
foot. Based on mineralogical, elemental and stable isotope analyses, this study aims at exploring the origin of the brine fluid and
the key biogeochemical processes controlling the formation of these deep-sea authigenic carbonates. In addition to their patchy
occurrence in...
Tipo: Text
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00186/29735/28189.pdf