alluvium


Also found in: Dictionary, Thesaurus, Medical, Acronyms, Encyclopedia, Wikipedia.

alluvium

The material deposited on land by virtue of the process of accretion. The accretion process occurs when rivers or other waters deposit silt and mud on land,and thus create more land; the silt and mud making up the new land is called alluvium.

References in periodicals archive ?
Hence, the most isotopically depleted samples in the study area, which are the Tertiary and a few alluvium samples close to the UAE border, are likely to form during the early to middle Holocene time when the climatic conditions were different from todays.
The interpretation of the VES sounding curve realized close to the borehole indicates that the geoelectric section is composed of six layers: (1) the first three thin near surface layers have high resistivities ranging from 58 to 372 ohm-m and a total thickness of 7.5 m that correspond to top soil and dry alluviums; (2) the 42 m thick fourth layer has an intermediate resistivity of 19 ohm-m and is composed of alluvium; (3) the fifth layer has a relatively high resistivity of 47 ohm-m and also is an aquifer; and (4) the sixth and bottom layer is the conductive geoelectric basement with an average resistivity of 12 ohm-m that is composed mainly of clays.
The gravity, modeling the bulk density of the alluvium was given 2.4 g/[cm.sup.3], and the basement density was given 2.67 g/[cm.sup.3].
In the study area lithological units is outcrops the second to fourth periods, which from old to new are as follows: phyllite, ouartzite, paragneiss, marble, shell, sandstone with tufa, volcanic rocks, crystalline limestone locally with fosolina, metamorphic volcanic and tufa, cherty limestone, phyllite, metamorphic quartzarenite, micaschist, metadolomite, amphibolite, limestone, shale and sandstone, schist hornfels, orthogneiss, granodiorite, oput rock, shale and phyllite sandstone, granite, granodiorite, diorite, dolomitic lime, radiolarit breccia, rodist lime, orbitoline, radiolarat, black and blue marl with limestone, alluvium. Alluvium of quaternary period consisting of sand, clay, silt and gravel covered the surface of the plain.
The top layer of the alluvium consists of sandy gravels/ gravelly sand having a thickness of about 15 m (Layer-1).
This zone is traceable for over 30km as discrete anomalies variously determined from soil, auger and vacuum programmes separated by areas of either alluvium or areas of no sampling.
In the south and west, the Old Alluvium pedoderm has various components: meander plain, backplain, and infilled channels.
In 1971, the United Nations Children's Fund launched a campaign to drill hand-pumped tubewells into the Ganges Delta alluvium. Hailed as a public health coup, the effort led to a plummet in waterborne microbial diseases throughout Bangladesh.
Sediments in both units become finer-grained away from the rise, indicating that the Lost River rise is the dominant source of floodplain alluvium. Stratigraphic and sedimentologic evidence indicate a shift in sedimentation style, attributable to climatic and/or anthropogenic influences.
But the colours also set up a procession of planes revealing the spatial nature of the composition, which, the architects argue, 'is a plain rectangular volume excavated by narrow open spaces conceived as cracks in hardened sand' like the raddled cliffs of ancient alluvium that form the seaside.
But, 1998 Knights Valley Alluvium Blanc was not a perennial favorite in these here parts.
Graphs of the water levels have been constructed for wells in the Red River alluvium in Caddo Parish for the years 1972 to 1982 to develop a systematic view of the well behavior before construction of the Red River Waterway.