We present new evidence for dark mafic sediment layers, exposed at impact crater or pit walls as well as on impact crater floors, to embody local sources for the dark aeolian dunes material on Mars. CTX, HiRISE, HRSC and CRISM data prove that those layers have a wider geographical distribution as previously thought. Age determinations of selected source regions led suggest that the exposure tim...

The distribution of hexabromocyclododecane (HBCD) in the sediment of three Japanese rivers with different characteristics (i.e., population and potential source in the catchment) was investigated and compared with the results estimated using a multimedia fate model (ChemCAN). High concentrations of HBCD in sediments in the range of 134-2060 ng g(-1) were found in a river receiving textile waste...

rockfill dams are accounted as useful measures in watershed management projects. how-ever, the sediment transport through the rockfill materials, could impact their lifetime duration. previously, researches have been conducted to describe the various hydraulically issues of the flow passing through these structures however; there is no general relationship to estimate the sediment transport rat...

this article present the result from a study of two sediment cores collected from theenvironmentally distinct zones of ces. accumulation status of five toxic metals: cadmium (cd), chromium(cr), cobalt (co), copper (cu) and lead (pb) were analyzed. besides texture and chns were determined tounderstand the composition of the sediment. enrichment factor (ef) and anthropogenic factor (af) wereused ...

Burial of organic carbon in marine sediments has a profound influence in marine biogeochemical cycles and provides a sink for greenhouse gases such as CO2 and CH4. However, tracing organic carbon from primary production sources as well as its transformations in the sediment record remains challenging. Here we examine a novel but growing tool for tracing the biosynthetic origin of amino acid car...

As part of a study using lake sediments to determine the extent and causes of human impacts to lakes along an east–west transect following the Yangtse River, sediment cores were taken from Taihu in eastern China. Previous studies have focussed on the impacts of direct inputs of pollutants from municipal and industrial wastewater but little work has been undertaken on trends in atmospheric depos...

A substantial amount of laboratory and field research on selenium effects to biota has been accomplished since the national water quality criterion was published for selenium in 1987. Many articles have documented adverse effects on biota at concentrations below the current chronic criterion of 5 microg/L. This commentary will present information to support a national water quality criterion fo...

Sediments in eight types of mangroves were sampled in the Leizhou Peninsula. Heavy metals were analyzed to investigate the effects on metal distribution of mangrove communities, to evaluate contamination levels, identify sources and relationships between the two. Results showed that mangrove communities have effects on most heavy metal distributions in sediments, especially in the sediment with...