A new extraction technique now permits ultrafine magnetite crystals to be separated from a variety of deep-sea sediments. Morphologic characterization of these particles with transmission electron microscopy reveals the presence of several distinct crystal types, some of which closely resemble those formed by the magnetotactic bacteria. The apparently biogenic magnetite particles are of single-...

This is the first in a pair of papers in which we present image-processing-based procedures for the measurement of fluvial gravels. The spatial and temporal resolution of surface grain-size characterization is constrained by the time-consuming and costly nature of traditional measurement techniques. Several groups have developed image-processing-based procedures, but none have demonstrated the ...

Floodplain soils and reservoir sediments are known for their fine-grained structure rich organic-matter substances; therefore, they able to sorb metals other potential pollutants, which is characteristic of sink function [...]

In this study, 166 surface sediments and 3 sediment cores from the Bohai Sea (BS), Yellow Sea (YS) and East China Sea (ECS) in China were collected to investigate the spatial and temporal distributions and the transport of PFASs. PFASs concentrations in the surface sediments ranged from below detection limit (<LOD) to 2.78 ng g(-1) with an average value of 0.55 ng g(-1) on a dry weight basis (d...

Disturbance strongly impacts patterns of community diversity, yet the shape of the diversity-disturbance relationship remains a matter of debate. The topic has been of interest in theoretical ecology for decades as it has practical implications for the understanding of ecosystem services in nature. One of these processes is the remineralization of organic matter by microorganisms in coastal mar...

Seventeen sites on the Amazon Fan were drilled during Leg 155. Although the oldest recovered sediment dates from isotopic Stage 8 (~0.25 Ma), our sampling concentrated on the last glacial cycle. Sites were correlated by seismic reflection profiles, paleomagnetic orientation and intensity, stable isotopes of planktonic foraminifers, and biostratigraphic methods. The Amazon Fan aggraded during lo...