Fluvial deposit

The materials so transported are deposited in a new environment, on land (terrestrial deposition), rivers (fluvial deposition), along coastal areas (marginal deposition) or on the sea floor (marine deposition). Dissolved components are deposited either by precipitation, or by evaporation or by the action of biological agencies. 

The heterogeneity of porous media with respect to their hydraulic permeability poses one of the most difficult problems. This is especially true for aquifers formed by glacial and fluvial deposits. Prediction of breakthrough curves may become impossible if a few long macropores or highly conducting layers are present in which water moves at a speed 10 or 100 times faster than the effective mean velocity. Such situations are still full of surprises, even to the specialist. 

The total range in shell 8180 values for each stratigraphic interval is shown in Figure 9a. Fossil teeth were collected from fluvial deposits in the Siwaliks of Pakistan, and were first analyzed for carbon isotopes to infer paleodiets (Quade et al. 1992). One archeological and four geological horizons were analyzed. Partial annual cycles are obvious in the equid and bovid teeth (Fig. 10a), and total ranges in compositions for samples pre- vs. post-8 Ma are similar (Fig. 10b). 

The six deposits have many characteristics in common. The fossil remains include a mixture of large and small mammals, small birds, small reptiles, and aquatic vertebrates. The bones and teeth of megavertebrates deposited amongst stream cobbles are relatively unworn, suggesting little transportation. Most of the sediments are an inhomogeneous mixture of large and small vertebrate remains, stream cobbles, clays, and cavities. None are stratified and yet all seem to be fluvial deposits. Most are poorly packed with inter-... 

Fluvial Deposition or precipitation in valleys and channels, or deposition or alteration by sheet-flood action... 

Fluvial deposits (in isolation, and commonly as streams feeding the closed lake basins, Figure 10.3C) (f) alluvial fan-sandflat, (g) ephemeral stream floodplain and (h) perennial stream floodplain. 

Deposition (aggradational) coasts are the most common type occurring at the southern and eastern margins of the Aral. They are usually low (1.0-1.5 m), and built of loose marine and fluvial deposits (quartz sands with shed debris). The lowest parts are flooded and form channels between the low islets, locally beating eolian dunes. 

North, C.P. Taylor, K.S. (1996) Ephemeral-fluvial deposits integrated outcrop and simulation studies reveal complexity. Bull. Am. Ass. Petrol. Geol., 80, 881-883. 

The Permo-Triassic Cooper basin of central Australia (Fig. 1) is Australia s largest onshore hydrocarbon province, containing about 6 TCF of recoverable gas and 300 MMSTB of oil and gas liquids (Heath, 1989 Laws, 1989). The basin consists dominantly of lacustrine-fluvial deposits with local glaciofluvial and rare paraglacial aeolian sediments (see Kapel, 1966, 1972 Gatehouse, 1972 ... 

Metal release from tidal Elbe river sediments by a process of oxidative remobilization has been described by Kersten (1989) (Figure 8.2). Short (30-cm) sediment cores were taken from a site, where diurnal inundation of the fine-grained fluvial deposits take place. In the upper part of the sediment column, total particulate cadmium content was 10 mg kg whereas in the deeper anoxic zone the total particulate concentration of Cd was 20 mg kg h Sequential extractions indicate that in the anoxic zone 60 -80% of the Cd was associated with the sulfidic/organic fraction. In the upper (oxic and transition) zone, the association of Cd in the carbonatic and exchangeable fractions simultaneously increase up to 40% of total Cd. This distribution suggests that the release of metals from particulate phases into the pore water and further transfer into biota is controlled by the frequent downward flux of oxygenated surface water. From the observed concentrations, it would be expected that long-term transfer of up to 50% of the Cd from the sediment subsurface would take place either into the anoxic zone located further below the sediment-water interface or released into the open water. 

Most of the allochthonous, or foreign, sources represent carbon with lower concentrations ( older radiocarbon ages) than the fraction of TOC originating from phytoplanktonic production. The only exception is the rapid transport and sedimentation of recently synthesized terrestrial plant material, which is in equilibrium with the " C concentration of atmospheric CO2. Other sources of nonmarine carbon typically are of intermediate (lO lO" years) or infinite A C (beyond the detection limit of 50-60 000 years) radiocarbon age, depending on the amount of time spent in other reservoirs such as soils, fluvial deposits, or carbon-rich rocks. 

Lacustrine silts and clays overlain by glacial fluvial deposits... 

Menior Point Fluvial deposits of sands, silts, General bank failure occurred in U.S. Corps of... 

Grijalva River, Fluvial deposit of fine sand 5 m Subsidence of rubble mound Zeevaert (1983)... 

Fluvial deposit at mouth of river with rubble mound jetties. 

Fluvial deposits of sandy silts and clays along rivers or coasts. 

CoUinson JW, Stanley KO, Vavra CL (1981) Triassic fluvial depositional systems in the Fremouw Formation, Cumulus HUls, Antarctica. In Cresswell MM, Vella PP (eds) Gondwana Five. Balkema, Rotterdam, The Netherlands, pp 141-148... 

Collinson JW, Kemp NR (1983) Permian-Triassic sedimentary sequence in northern Victoria Land, Antarctica. In Oliver RL, James PR, Jago JB (eds) Antarctic earth sciences. Australian Academy of Science, Canberra, Australia, pp 221-225 Collinson JH, Pennington DC, Kemp NR (1986) Stratigraphy and petrology of Permian and Triassic fluvial deposits in northern Victoria Land. In Stump E (ed) Geological investigations in northern Victoria Land. Antarctic Res Ser 46 211-242... 

Sampling of surface waters consists in taking a representative part of the water body or other component of the environment (water, fluvial deposits, sediments, biological material) to determine various, exactly defined, quality indicators. This list indicates the great variability of sampling plans. 

A number of sandstone-type uranium occurrences have been found in the Permian continental sandstones of the southern Alps—the Collio and Verrucano Lombardo formations in the central Alps, the Val Gardena sandstones in the Trentino-Alto Adige region and the eastern Alps (Fig. 1). These clastic fluvial deposits overlie either directly the pre-Hercynian crystalline basement or the post-orogenic volcanics and are overlain by epicontinental sediments. 

Early in the Pleistocene epoch much of the present Netherlands was submerged. With time marine and fluvial deposits built up the land. Around 5000 years ago the coastline consisted of a sandy coastal zone, mud flats, salt marshes, and peat bogs. The subsequent formation of coastal dunes closed off the area of mud flats and salt marshes resulting in an increase of peat growth. Figure 84.1 shows the coastline around 800 A.D. when the shape was a result of natural forces only. Note Lake Almere in the center of the region. 

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