Geochemistry and Sedimentology of the Mediterranean Sea

Emelyanov, Emelyan M; Shimkus, K. M.

doi:10.1007/978-94-009-4490-9

Cited by 50 publications

(29 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…We conservatively assume that the isolation was instantaneous and that no further marine input occurred until the Sr-isotope ratio was altered by the required amount. The maximum volume of the western Mediterranean Sea was approximately 1424 x I0 3 km 3 (854.6 x I0 3 km 2 surface x 1.67 km deep; Emelyanov and Shimkus, 1986). The Sr concentration in seawater is 8000 /xg/L and, thus, the western Mediterranean contains 1.1392 x I0 16 g of Sr. For the Rhone, Ebro, and Tiber a mean Sr concentration of 500 ^cg/L is assumed (Albarede and Michard, 1987) and the annual discharge of these rivers is 2525 m 3 /s (Emelyanov and Shimkus, 1986).…”

Section: What Process Could Have Produced the Low Sr Isotopic Ratios mentioning

confidence: 93%

“…The maximum volume of the western Mediterranean Sea was approximately 1424 x I0 3 km 3 (854.6 x I0 3 km 2 surface x 1.67 km deep; Emelyanov and Shimkus, 1986). The Sr concentration in seawater is 8000 /xg/L and, thus, the western Mediterranean contains 1.1392 x I0 16 g of Sr. For the Rhone, Ebro, and Tiber a mean Sr concentration of 500 ^cg/L is assumed (Albarede and Michard, 1987) and the annual discharge of these rivers is 2525 m 3 /s (Emelyanov and Shimkus, 1986). These data imply that it would have taken 1.1392 (Clauer, 1976) suggest that the evaporites from different basins in the Mediterranean Sea may have had distinct 87 Sr/ 86 Sr compositions (Fig.…”

Section: What Process Could Have Produced the Low Sr Isotopic Ratios mentioning

confidence: 93%

See 1 more Smart Citation

Strontium Isotopic Ratios as Fluid Tracers in Messinian Evaporites of the Tyrrhenian Sea (Western Mediterranean Sea)

Müller¹,

Mueller²,

McKenzie³

1990

Proceedings of the Ocean Drilling Program

View full text Add to dashboard Cite

Strontium isotopic ratios of gypsums recovered from upper Miocene (Messinian) evaporites at ODP Leg 107 Holes 652A, 653B, and 654A (Tyrrhenian Sea) Sr-ratio for evaporites in the sedimentary cycles recognized for Holes 653B and 654A, the generally low Sr isotopic ratio of river water entering the Mediterranean Sea, and the presence of dwarf marine microfossils suggest that the 87 Sr/ 86 Sr ratio of the evaporites responded to hydrologic variations in a very restricted basin with variable rates of marine and fresh water input. The strontium isotopic ratios of the Messinian anhydrites from the proposed lacustrine sequence at Hole 652A fall in the same range as the marine evaporites from Holes 654A and 653B. This suggests a common or similar origin of the brines at the three locations.The complex depositional and hydrologic conditions in the Mediterranean during the Messinian salinity crisis preclude the use of Sr isotopic values from the evaporites for stratigraphic correlation and dating. They are, however, very useful in the interpretation of the depositional history of the basin. General calculations assuming a closed system suggest that the 87 Sr/ 86 Sr ratio of Messinian seawater (-0.7090) could be reduced to that of the evaporites (-0.7087) by mixing with fresh water (e.g., Nile River) in times of I0 4 to I0 5 yr.

show abstract

Section: What Process Could Have Produced the Low Sr Isotopic Ratios mentioning

confidence: 93%

Section: What Process Could Have Produced the Low Sr Isotopic Ratios mentioning

confidence: 93%

Strontium Isotopic Ratios as Fluid Tracers in Messinian Evaporites of the Tyrrhenian Sea (Western Mediterranean Sea)

Müller¹,

Mueller²,

McKenzie³

1990

Proceedings of the Ocean Drilling Program

View full text Add to dashboard Cite

show abstract

“…The sediment collected during this relative maximum had the lowest opal content found in the whole set of sediment trap samples of this study. This near-absence of opal is indicative of reworked sediments, since the relatively high pH and temperature of the Mediterranean deep water promotes an intense dissolution of the particulate opal that reaches the sea floor (Emelyanov and Shimkus, 1986;Cros, 1995), and bottom sediments are thus very poor in this constituent . This opal marked minimum was also accompanied by low values of organic carbon and 210 Pb, suggesting resuspension of old sediments.…”

Section: Sediment Gravity Flows In the Canyonmentioning

confidence: 99%

Composition and variability of downward particulate matter fluxes in the Palamós submarine canyon (NW Mediterranean)

Martín

Palanqués

Puig

2006

Journal of Marine Systems

View full text Add to dashboard Cite

To study the temporal and spatial variability of downward particle fluxes in the Palamós Submarine Canyon, seven sediment traps were moored inside and in the vicinity of the canyon from March to November 2001. Total mass fluxes, major constituent (organic carbon, opal, calcium carbonate and lithogenics) contents and fluxes, and 210 Pb activity of particulate matter were obtained from two consecutive deployments at intervals of 10 and 12 days respectively. Downward particle fluxes measured at the Palamós Canyon head were 2 to 9 times higher than those measured in other northwestern Mediterranean canyons, and this relation increases drastically at 1200 m depth, where observed particle fluxes are 1 to 2 orders of magnitude higher than those reported in other surrounding canyons at similar depths. The highest near-bottom downward particle fluxes were not recorded in the canyon head but in the mid-canyon axis during late spring/summer, as a result of sediment gravity flows triggered by trawling activities at the canyon rims. In comparison to the adjacent open slope, Palamós Canyon is a prime site for the focusing and across-margin transference of total and organic matter. Off-shelf sediment transport was enhanced during a severe storm in November 2001, when a sharp increase in downward particulate fluxes was observed in the whole canyon both near the bottom and at intermediate waters. Despite the dominance of lithogenic particles all year round, a siliceous bloom affected the whole study area in March-April. An asymmetrical pattern was observed between the north and south canyon walls, with higher mean downward fluxes in the latter case, a fact related to the flow regime inside the canyon. The spatial-temporal distribution of total mass fluxes and major constituents defined two domains in the Palamós Canyon: an "inner" domain (up to 1200 m depth) constricted by the canyon topography and mainly influenced by a lateral transport of particles resuspended from the adjoining shelf and upper slope, and an "outer" domain, where slope dynamics and seasonal trends are more important in determining the composition and amount of downward particulate fluxes.

show abstract

“…A tentative P budget for the eastern Mediterranean before anthropogenic perturbation is presented in Figure 8A. Sediment P burial was estimated from the average total P flux after S1 at two-low sedimentation (Table 2) and a high-sedimentation site in the southern Aegean Sea (present day: ϳ1530 mol m Ϫ2 yr Ϫ1 ; data not shown) and the area of the eastern Mediterranean (1.6 ϫ 10 12 m 2 ; Sarmiento et al, 1988), assuming that high and low sedimentation areas each cover 50% (based on water depths; Emelyanov and Shimkus, 1986). In this type of circulation, net outflow of P occurs at the Strait of Sicily as a result of the import of nutrient-depleted surface waters and the export of nutrients in the intermediate water.…”

Section: Role Of P In Sapropel S1 Formationmentioning

confidence: 99%

Enhanced regeneration of phosphorus during formation of the most recent eastern Mediterranean sapropel (S1)

Slomp

Thomson

Lange

2002

Geochimica et Cosmochimica Acta

142

145

View full text Add to dashboard Cite

Abstract-Phosphorus regeneration and burial fluxes during and after formation of the most recent sapropel S1 were determined for two deep-basin, low-sedimentation sites in the eastern Mediterranean Sea. Organic C/P ratios and burial fluxes indicate enhanced regeneration of P relative to C during deposition of sapropel S1. This is largely due to the enhanced release of P from organic matter during sulfate reduction. Release of P from Fe-bound P also increased, but this was only a relatively minor source of dissolved P. Pore-water HPO 4 2Ϫ concentrations remained too low for carbonate fluorapatite formation. An increased burial of biogenic Ca-P (i.e., fish debris) was observed for one site. Estimated benthic fluxes of P during sapropel formation were elevated relative to the present day (ϳ900 to 2800 vs. ϳ70 to 120 mol m Ϫ2 yr Ϫ1 ). The present-day sedimentary P cycle in the deep-basin sediments is characterized by two major zones of reaction: (1) the zone near the sediment-water interface where substantial release of HPO 4 2Ϫ from organic matter takes place, and (2) the oxidation front at the top of the S1 where upward-diffusing HPO 4 2Ϫ from below the sapropel is sorbed to Fe-oxides. The efficiency of aerobic organisms in retaining P is reflected in the low organic C/P ratios in the oxidized part of the sapropel. Burial efficiencies for reactive P were significantly lower during S1 times compared with the present day (ϳ7 to 15% vs. 64 to 77%). Budget calculations for the eastern Mediterranean Sea demonstrate that the weakening of the antiestuarine circulation and the enhanced regeneration of P both contributed to a significant increase in deep-water HPO 4 2Ϫ concentrations during sapropel S1 times. Provided that sufficient vertical mixing occurred, enhanced regeneration of P at the seafloor may have played a key role in maintaining increased productivity during sapropel S1 formation.

show abstract

Geochemistry and Sedimentology of the Mediterranean Sea

Cited by 50 publications

References 0 publications

Strontium Isotopic Ratios as Fluid Tracers in Messinian Evaporites of the Tyrrhenian Sea (Western Mediterranean Sea)

Strontium Isotopic Ratios as Fluid Tracers in Messinian Evaporites of the Tyrrhenian Sea (Western Mediterranean Sea)

Composition and variability of downward particulate matter fluxes in the Palamós submarine canyon (NW Mediterranean)

Enhanced regeneration of phosphorus during formation of the most recent eastern Mediterranean sapropel (S1)

Contact Info

Product

Resources

About