The Danube submarine canyon (Black Sea): morphology and sedimentary processes

Popescu, Irina; Lericolais, Gilles; Panin, Nicolae; Normand, Alain; Dinu, C.; Drezen, E. Le

doi:10.1016/j.margeo.2004.03.003

Cited by 163 publications

(115 citation statements)

References 32 publications

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“…An increase of Hippophae indicates more open landscapes in the catchment area, which could be either the result of drier climatic conditions and/or increased delta dynamics and/or a possible decrease of the sea level of the Black Sea at the end of MIS 3. However, since the general trends in vegetation dynamics suggest development of wetter conditions in northern Anatolia, a combination of the two latter processes is very likely and are in agreement with reconstructed low levels of the Black Sea during the late Pleistocene (Popescu et al, 2004).…”

Section: Long-term Dynamicssupporting

confidence: 68%

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Orbital- and millennial-scale environmental changes between 64 and 20 ka BP recorded in Black Sea sediments

Shumilovskikh¹,

Fleitmann

Nowaczyk

et al. 2014

Clim. Past

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Abstract. High-resolution pollen and dinoflagellate cyst records from sediment core M72/5-25-GC1 were used to reconstruct vegetation dynamics in northern Anatolia and surface conditions of the Black Sea between 64 and 20 ka BP. During this period, the dominance of Artemisia in the pollen record indicates a steppe landscape and arid climate conditions. However, the concomitant presence of temperate arboreal pollen suggests the existence of glacial refugia in northern Anatolia. Long-term glacial vegetation dynamics reveal two major arid phases ∼ 64-55 and 40-32 ka BP, and two major humid phases ∼ 54-45 and 28-20 ka BP, correlating with higher and lower summer insolation, respectively. Dansgaard-Oeschger (D-O) cycles are clearly indicated by the 25-GC1 pollen record. Greenland interstadials are characterized by a marked increase in temperate tree pollen, indicating a spread of forests due to warm/wet conditions in northern Anatolia, whereas Greenland stadials reveal cold and arid conditions as indicated by spread of xerophytic biomes. There is evidence for a phase lag of ∼ 500 to 1500 yr between initial warming and forest expansion, possibly due to successive changes in atmospheric circulation in the North Atlantic sector. The dominance of Pyxidinopsis psilata and Spiniferites cruciformis in the dinocyst record indicates brackish Black Sea conditions during the entire glacial period. The decrease of marine indicators (marine dinocysts, acritarchs) at ∼ 54 ka BP and increase of freshwater algae (Pediastrum, Botryococcus) from 32 to 25 ka BP reveals freshening of the Black Sea surface water. This freshening is possibly related to humid phases in the region, to connection between Caspian Sea and Black Sea, to seasonal freshening by floating ice, and/or to closer position of river mouths due to low sea level. In the southern Black Sea, Greenland interstadials are clearly indicated by high dinocyst concentrations and calcium carbonate content, as a result of an increase in primary productivity. Heinrich events show a similar impact on the environment in the northern Anatolia/Black Sea region as Greenland stadials.

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Section: Long-term Dynamicssupporting

confidence: 68%

“…During MIS 2, the Black Sea level dropped to 100 m b.s.l., evidenced by formation of the Danube Canyon (Popescu et al, 2004). A lower Black Sea level is supported in the 25-GC1 record by an increase in Hippophae percentages (see Sect.…”

Section: Long-term Patternsmentioning

confidence: 65%

Orbital- and millennial-scale environmental changes between 64 and 20 ka BP recorded in Black Sea sediments

Shumilovskikh¹,

Fleitmann

Nowaczyk

et al. 2014

Clim. Past

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“…4.1.A.). The region is wellknown for abundant gas seeps, carbonate buildups and shallow gas (Polikarpov et al, 1989;Polikarpov et al, 1992;Egorov et al, 1998;Luth et al, 1999;Peckmann et al, 2001;Thiel et al, 2001;Amouroux et al, 2002;Michaelis et al, 2002;Kruglyakova et al, 2004;Kutas et al, 2004;Popescu et al, 2004;Pape et al, 2005;Pimenov and Ivanova, 2005;Reitner et al, 2005;Schmale et al, 2005;Treude et al, 2005;McGinnis et al, 2006;Naudts et al, 2006). During the 58 th (May-June 2003) and 60 th (MayJune 2004) cruise of R.V.…”

Section: Study Areamentioning

confidence: 99%

Anomalous sea-floor backscatter patterns in methane venting areas, Dnepr paleo-delta, NW Black Sea

et al. 2008

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The relation between acoustic seafloor backscatter and seep distribution is examined by integrating multibeam backscatter data and seep locations detected by single-beam echosounder. This study is further supported by side scan sonar recordings, high-resolution 5 kHz seismic data, pore-water analysis, grain-size analysis and visual seafloor observations. The datasets were acquired during the 2003 and 2004 expeditions of the EC-funded CRIMEA project in the Dnepr paleo-delta area, northwestern Black Sea.More than 600 active methane seeps were hydro-acoustically detected within a small (3.96 km by 3.72 km) area on the continental shelf of the Dnepr paleo-delta in water depths ranging from -72 m to -156 m. Multibeam and side scan sonar recordings show backscatter patterns that are clearly associated with seepage or with a present dune area. Seeps generally occur within medium-to highbackscatter areas which often coincide with pockmarks.High-resolution seismic data reveal the presence of an undulating gas front, i.e. the top of the free gas in the subsurface, which domes up towards and intersects the seafloor at locations where gas seeps and medium-to high-backscatter values are detected. Pore-water analysis of 4 multi-cores, taken at different backscatter intensity sites, shows a clear correlation between backscatter intensity and dissolved methane fluxes. All analyzed chemical species indicate increasing anaerobic oxidation of methane (AOM) from medium-to high-backscatter locations. This is confirmed by visual seafloor observations, showing bacterial mats and authigenic carbonates formed by AOM. Grain-size analysis of the 4 multi-cores only reveals negligible variations between the different backscatter sites.Integration of all datasets leads to the conclusion that the observed backscatter patterns are the result of ongoing methane seepage and the precipitation of methane-derived authigenic carbonates (MDACs) caused by AOM. The carbonate formation also appears to lead to a gradual (self-)sealing of the seeps by cementing fluid pathways/horizons followed by a relocation of the bubble-releasing locations. KeywordsMethane seeps; acoustic seafloor backscatter; anaerobic oxidation of methane; bacterial mats; pockmarks; methane-derived authigenic carbonates

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“…Onshore rivers may connect canyons directly into the river mouth (Babonneau et al 2002;Yu et al 2009;Hsiung and Yu 2012) or erode their way into a continental shelf during a lowstand period (Damuth 1994;Popescu et al 2004;Anderson 2005;Ding et al 2010). Hyperpycnal currents generated in rivers drive sediment transport on the sea bottom, thereby favoring the formation of canyons or channels.…”

Section: High Sediment Inputmentioning

confidence: 99%

“…Several studies have illustrated the influence of tectonic deformation in controlling canyon location, orientation and morphology (Popescu et al 2004;Yu et al 2009;Dantec et al 2010). In the case of the Pearl River Canyon system, Cenozoic tectonics also have played a critical role in canyon location and formation.…”

Section: Structural Controlsmentioning

confidence: 99%

Morphotectonics and evolutionary controls on the Pearl River Canyon system, South China Sea

Ding

Li³

et al. 2013

Mar Geophys Res

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The Pearl River Canyon system is a typical canyon system on the northern continental slope of the South China Sea, which has significant implications for hydrocarbon exploration. Through swath bathymetry in the canyon area combined with different types of seismic data, we have studied the morphotectonics and controlling factors of the canyon by analyzing its morphology and sedimentary structure, as well as the main features of the continental slope around the canyon. Results show that the Pearl River Canyon can be separated into three segments with different orientations. The upper reach is NW-oriented with a shallowly incised course, whereas the middle and lower reaches, that are located mainly in the Baiyun Sag, have a broad U-shape and have experienced consistent deposition. Seventeen deeply-cut canyons have developed in the slope north of the Baiyun Sag, playing an important role in the sedimentary processes of the middle and lower reaches of the Pearl River Canyon. These canyons display both asymmetrical V-and U-shapes along their lengths. Numerous buried channels can be identified below the modern canyons with unidirectionally migrating stacking patterns, suggesting that the canyons have experienced a cyclic evolution with several cut and fill phases of varying magnitude. These long established canyons, rather than the upper reach of the Pearl River Canyon, are the main conduits for the transport of terrigenous materials to the lower slope and abyssal basin during lowstand stage, and have contributed to the formation of vertically stacked deep-water fans in the middle reach. Canyon morphology is interpreted as a result of erosive sediment flows. The Pearl River Canyon and the 17 canyons in the slope area north of the Baiyun Sag probably have developed since the Miocene. Cenozoic tectonics, sea level change and sediment supply jointly control the morphology and sedimentary structure. The middle and lower reaches of the Pearl River Canyon developed on the paleo-terrain of the Baiyun Sag, which has been a persistently rapid depositional environment, receiving most of the materials transported via the canyons.

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The Danube submarine canyon (Black Sea): morphology and sedimentary processes

Cited by 163 publications

References 32 publications

Orbital- and millennial-scale environmental changes between 64 and 20 ka BP recorded in Black Sea sediments

Orbital- and millennial-scale environmental changes between 64 and 20 ka BP recorded in Black Sea sediments

Anomalous sea-floor backscatter patterns in methane venting areas, Dnepr paleo-delta, NW Black Sea

Morphotectonics and evolutionary controls on the Pearl River Canyon system, South China Sea

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