Basin-scale calcification rates are highly important in assessments of the global oceanic carbon cycle. Traditionally, such estimates were based on rates of sedimentation measured with sediment traps or in deep sea cores. Here we estimated CaCO3 precipitation rates in the surface water of the Red Sea from total alkalinity depletion along their axial flow using the water flux in the straits of B...

To evaluate the effect of redox conditions at sedimentation stage on uranium content and U/TOC ratio in marine source rocks, we analyzed accumulation modern bottom sediments formed different conditions. The behavior from oxidizing sub-oxidizing settings has been studied Upper Pleistocene–Holocene age accumulated coastal area White Sea (Kandalaksha Gulf). We uranium, Eh, pH, TOC, C, H, N, S elem...

Spatial radionuclides distribution was studied in recent estuarine sediments in the Krka River Estuary. Sediment samples were analyzed for 40K and 232Th by gamma-spectrometry. Activities of 40K were found in the range of 18–457 Bq kg–1 and activities of 232Th in range of 1.9–29.4 Bq kg–1. Distribution of 232Th activities follows that of 40K, with correlation coefficients higher than 0.97 in all...

Sedimentary rocks are one component of the modern threefold classification of rocks. They derive from the lithification of sediments, which are produced in basically two ways: by the mechanical deposition of grains derived from the alteration of other rocks (detrital or clastic rocks), or as chemical precipitates or grains formed organically or inorganically from an aqueous solution. The whole ...

As for lineages of known methanogens, several lineages of uncultured archaea were recurrently retrieved in freshwater sediments. However, knowledge is missing about how these lineages might be affected and structured according to depth. In the present study, the vertical changes of archaeal communities were characterized in the deep sediment of the freshwater meromictic Lake Pavin. For that pur...

When natural degradation processes are slow and technological cleanup methods ineffective, plastic pollution is considered "poorly reversible" in that particular ecosystem. In areas where has had a harmful impact, it may be nearly impossible to reverse the damage. Weakly reversible can result changes carbon nitrogen cycles, alterations soil habitat, sedimentation, effects on aquatic ecosystems ...

this paper proposes an extension of markov chain model to characterize of geological formations and to make conditioning on any number of well data possible. in this study, lithofacies cycles of the amiran formation at type and pirshamsedin sections are examined by markov method and entropy analysis as well as field observations, and depositional environment has interpreted by proposed ideal se...

the gulf of mannar, located between india and sri lanka, is a shallow embayment of the bay of bengal. the gulf, which has been declared a bio-reserve is a highly productive area endowed with rich marine fauna including corals. in order to study the origin and nature of the sediments and paleo-environment, 2.6 m length core was collected with 5cm interval at 1320m water depths. textural studies ...

The 2010 Deepwater Horizon oil spill resulted in 1.6-2.6 × 10(10) grams of petrocarbon accumulation on the seafloor. Data from a deep sediment trap, deployed 7.4 km SW of the well between August 2010 and October 2011, disclose that the sinking of spill-associated substances, mediated by marine particles, especially phytoplankton, continued at least 5 mo following the capping of the well. In Aug...

The definition of a Middle–Upper Pleistocene Subseries boundary is discussed. This boundary is at present not formally defined, but has up till now been placed at the beginning of the Last Interglacial (Eemian, Mikulino, Sangamonian, etc.) or Marine Isotope Stage 5. Although it may seem attractive to define the boundary in an ocean sediment sequence, the inherent imprecision of most of such seq...