... detrital material received from temporary water flows, as well as with Aeolian transport. Most of the section of small lakes bottom sediments is composed of organomineral silts (sapropels) with a gradual increase in the amount of organic matter to the water-sediment boundary (in the sapropel part...

.... Lacustrine sediments are represented by the upper 293 cm. Each bed of the sediments is subjected to microbiological analysis. A high total number of heterotrophic bacteria is revealed in the upper (0–15 cm) and deeper (110–150 cm) sapropel intervals. Sulfate-reducing bacteria are identified only...

...G.A. Leonova; T.A. Kopoteva; V.N. Melenevskii; A.E. Maltsev; M.A. Klimin; V.A. Bobrov Abstract —We present results of study of the chemical composition of organic matter (C, H, N, and S) from Holocene sections of lake sapropels with undisturbed stratification penetrated by vibratory drilling...

...Nicole J. Bale; Rick Hennekam; Ellen C. Hopmans; Denise Dorhout; Gert-Jan Reichart; Marcel van der Meer; Tracy A. Villareal; Jaap S. Sinninghe Damsté; Stefan Schouten Abstract Sapropels are organic-rich sediment layers deposited in the eastern Mediterranean Sea during precession minima, resulting...

... analysis of the pyrolysis oil and pyrolysis gas. The results indicate that the surface sediments had poor to fair gas-prone hydrocarbon generation potential and that the type of insoluble OM was III-IV. The macerals were dominantly vitrinite, followed by sapropelic amorphogen. Bulk geochemistry data...

... epibathyal palaeonvironment in this Eastern Mediterranean area reacted to the palaeoclimate changes with the water mass stratification (warm periods) and/or with enhanced primary productivity (cool/cold periods) leading to the deposition of sapropel layers with different degrees of bottom oxygenation...

... of the sedimentary column: coccolith ooze with 2.8% C org at the top and sapropels oozes with 8.5% C org at the bottom. The deposition of Holocene sediments was inferred to take place under euxinic conditions, which are more favorable for organic-matter preservation and sapropel deposition during the Old Black Sea...

... carbon) in the rock and by its hydrogen content. Type I and II kerogens are dominated by sapropelic organic matter commonly deposited under oxygen-restricted conditions in marine or lacustrine environments. These kerogens are characterized by high H/C ratios and typically break down to form oil and gas...

...G.A. Leonova; V.A. Bobrov; S.K. Krivonogov; A.A. Bogush; V.A. Bychinskii; A.E. Mal’tsev; G.N. Anoshin Abstract The biogeochemistry of organic lacustrine sediments (sapropels) has been poorly studied in Siberia. In this paper we show the specifics of sapropel formation caused by low pH...

... imaging of eastern Mediterranean sapropels (Pliocene–Pleistocene age from Ocean Drilling Program drill sites) was performed on samples prepared by Ar-ion cross-section polishing. The immaturity of marine kerogen in these rocks allows inspection of petrographic textures without overprints related...

...V.D. Strakhovenko; O.P. Taran; N.I. Ermolaeva Abstract More than 20,000 lakes with sapropel sediments are located in southern West Siberia. The work is aimed at an integrated geochemical study of ten sapropel lake systems: a geochemical description of the lake waters, hydrobiological analysis...

...Alice M. Milner; Richard E.L. Collier; Katherine H. Roucoux; Ulrich C. Müller; Jörg Pross; Stavros Kalaitzidis; Kimon Christanis; Polychronis C. Tzedakis Abstract The deposition of sapropels in the eastern Mediterranean Sea is thought to occur during intervals of intensified African monsoon...

...Luigi Vigliotti; Alessandra Asioli; Caterina Bergami; Lucilla Capotondi; Andrea Piva Abstract The youngest sapropel S1 has been investigated by a multiproxy study on a core (ET99-M11) collected in the western Ionian Sea at a water depth of 2800 m, which is considered to represent anoxic conditions...

... yr BP. The high African monsoon index for this pre-Holocene time corresponds with pollen evidence of relatively high Nile discharge. The organic-rich S1 sapropel sediments, dated as around 9,500–6,270 yr BP, were deposited several thousand years later, during a time of lower Monsoon index, warmer...

...SIMONA STEFANELLI; LUCILLA CAPOTONDI Abstract Foraminifera were investigated across the sapropel unit corresponding to insolation cycle 90 deposited in three different oceanographic and depositional settings of the Mediterranean Sea (Alboran Sea, South Adriatic Sea and Ionian Sea). The constant...

... to climate forcing, driving large-scale hydrographic adjustments throughout the eastern Mediterranean and beyond. 17 03 2007 24 02 2007 16 03 2007 Geological Society of America 2007 Mediterranean Sea thermohaline circulation sapropels stable isotopes biomarkers...

... was therefore a true sapropel at the time of deposition. This result indicates that anoxic conditions are not a prerequisite for sapropelic sediment formation. However, the pristine concentration of the organic carbon in the dark layers at Punta Piccola is lower than those of coeval sapropels cored...

... for the placement and age of archaeological sites in the Koobi Fora Formation, and for ages of mammalian faunas (including hominids). Many tuffs were deposited during a 90 ka interval during which Mediterranean sapropels are lacking, suggesting that Nile flow was reduced, and that the level of a lake that occupied...

...Leon Moodley; Jack J. Middelburg; Peter M.J. Herman; Karline Soetaert; Gert J. de Lange Abstract Clarification of the factors involved in the formation of unusual ancient organic carbon– rich deposits (like eastern Mediterranean sapropels) is central in understanding oceanic carbon cycling...