Of the *240 9 10 mol year of biogenic silica (bSi) produced by diatoms and other silicifying organisms, only roughly 3%–4% escapes dissolution to be permanently buried. At the global scale, how, where and why bSi is preserved in sediment is not well understood. To help address this, I compile 6245 porewater dissolved Si concentrations from 453 sediment cores, to derive the concentration gradien...

There is evidence for 10 mechanisms of sediment distribution in small lakes. The sediment accumulation rates measured from a common horizon in cores from 64 sites on Esthwaite Water, U.K., were used to determine the relative importance of these mechanisms on the distribution of sediment in the lake. River inflows generally produced localized effects but there were indications of periodic turbid...

Seismic reflection profiles and the structure of sediments in box cores from Ontong-Java Plateau indicate large-scale land sliding and sediment flow processes, respectively. The topographic morphology of sliding and slumping is depth- dependent, suggesting control by dissolution processes.

the karnafully is one of the most important rivers due to its profound influence on water chemistry and sediment characteristics. the present study intended to assess the quality of water and sediment from intertidal zone of this river in respect to the pollution index. seasonal water and sediment samples were collected during four seasons (monsoon, post-monsoon, winter, and pre-monsoon) of 201...

Recent years have seen a growing awareness of the wider environmental significance of the suspended sediment loads transported by rivers and streams. This includes the importance of fine sediment in the transport of nutrients and contaminants, including phosphorus (P). Sediment source exerts a key control on the physical and geochemical properties of suspended sediment, including its P content,...

We developed records of clastic sediment flux to 13 alpine lakes in Peru, Ecuador, and Bolivia, and compared these with independently dated records of regional glaciation. Our objectives are to determine whether a strong relationship exists between the extent of ice cover in the region and the rate of clastic sediment delivery to alpine lakes, and thus whether clastic sediment records serve as ...

The Karnafully is one of the most important rivers due to its profound influence on water chemistry and sediment characteristics. The present study intended to assess the quality of water and sediment from intertidal zone of this river in respect to the pollution index. Seasonal water and sediment samples were collected during four seasons (Monsoon, post-monsoon, winter, and pre-monsoon) of 201...

Sediment cores were collected from the Xiangxi River, a tributary of Three Gorges Reservoir, deposition time in longest sediment core (90 cm) was measured by radiometry (137Cs, 210Pb) activities and polychlorinated dibenzo-p-dioxins/furan (PCDD/F) concentrations different depths measured. The results indicated that mean rate 1.01 cm/a. total PCDD/F ranged 19.28 to 70.07 pg/g d.w. with 35.06 PCD...

We examined the anthropogenic lead (Pb) burden that accumulated in sediment of lakes in the southeastern USA during the last *150 years. Mining, smelting, agriculture, and fossil-fuel combustion are known to have contributed to Pb pollution in lakes of other regions. Few studies, however, have examined Pb sequestered in lakes of the southeastern USA, particulary peninsular Florida, which is sub...

Dating lake sediments by accelerator mass spectrometry (AMS) C analysis of terrestrial plant macrofossils overcomes one of the main problems associated with dating bulk sediment samples, i.e., the presence of old organic matter. Even so, many AMS dates from arctic and boreal sites appear to misrepresent the age of the sediment. To understand the nature of these apparent dating anomalies better,...