Environment fluvial

Methyltriclosan is a rarely reported contaminant in riverine sediments. It enters the fluvial environment via municipal effluents. The concentrations detected in the sediment core investigated range between 1 and 28 ng/g. The first occurrence of methyltriclosan was detected at a depth of 46 cm with very low values (Fig. 7E). A concentration maximum is reached at a depth between 14 and 6 cm. 

Newson, M.D. and Leeks, G.J. (1985) Mountain bedload yields in the United Kingdom further information from undisturbed fluvial environments. Earth Surface Processes Landf, 10, pp. 413-416. 

In the shallow regions of the Athabasca deposit, the oil is in a drainage basin that was filled in with sediments as it was alternately flooded by a sea (estuarial environment) and then rivers (fluvial environment), so that a number of distinct depositional environments of estuarine and marine sediment occurred (10—15). As a result, the oil-bearing sands have great variability in their compositions and properties. 

Figure 2.9. Depositional structures in a fluvial environment. (http //www.carleton.ca/ tpatters/teaching/ intro/depoenvironments/depoenvironments 7. html)...

Laushey worked during his professional career on a wide range of hydraulic problems. His PhD thesis was concerned with the measurement of turbulent fluctuations in flows as the hydraulic jump, so that he may be considered a predecessor of the works made at the Iowa Institute of Hydraulic Research then directed by Hunter Rouse (1906-1996). The 1947 paper deals with similar aspects of tailwater characteristics beyond a hydraulic jump to avoid erosion in the downstream river. The entrainment of sediment in the fluvial environment, as first detailed by Albert Shields (1908-1974), was investigated in the 1949 paper, eo-authored by Frederick T. Mavis (1901-1983). The 1953 paper was concerned with shaft hydraulics, a topic then almost unknown but important in many application of the daily life. 

In addition to schwertmannite, some other minerals of Fe(in) are commonly recognized in the AMD systems, with a close relation between their occurrence and the water pH (Table 1). Jarosite is usually favored to precipitate from very acidic solutions, normally at pH < 2. Schwertmannite precipitates near the discharge points at pH 2.0-4.0, whereas ferrihydrite usually forms in fluvial environments (as in the confluences between AMD and unpolluted rivers) at... 

In every exploration program it is a must to find out in what kind of deposi-tional environment the investigated rocks were generated. To locate reservoirs it has to be known if they were generated in a deltaic, fluvial or reef environment. Reservoir sands in a reef environment show a different seismic facies than sands of a fluvial environment. If the depositional environment of a sedimentary rock is known then further exploration and production strategies can be refined and optimised. A tool to describe depositional environments out... 

For example, the many deepwater fields located in the Gulf of Mexico are of Tertiary age and are comprised of complex sand bodies which were deposited in a deepwater turbidite sequence. The BP Prudhoe Bay sandstone reservoir in Alaska is of Triassic/ Cretaceous age and was deposited by a large shallow water fluvial-alluvial fan delta system. The Saudi Arabian Ghawar limestone reservoir is of Jurassic age and was deposited in a warm, shallow marine sea. Although these reservoirs were deposited in very different depositional environments they all contain producible accumulations of hydrocarbons, though the fraction of recoverable oil varies. In fact, these three fields are some of the largest in the world, containing over 12 billion barrels of oil each ... 

Johnsson, M. J., Stallard, R. F., and Lundberg, N. (1991). Controls on the composition of fluvial sands from a tropical weathering environment Sands of the Orinoco River drainage basin, Venezuela and Colombia. Geol. Soc. Am. Bull. 103,1622-1647. 

Pinay G, Clement JC, Naiman RJ (2002) Basic principles and ecological consequences of changing water regimes on nitrogen cycling in fluvial systems. Environ Manage 30 481 91... 

Serra A, Guasch H (2009). Effects of chronic copper exposure on fluvial systems linking stmctural and physiological changes of fluvial biofilms with the in-stream copper retention. Sci Tot Environ 407 5274... 

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. 

All these contaminants enter into the environment through human activities (urban waste, deposits of the waste cleaning plants and agricultural cultivations) [45] and various other pathways (atmospheric and fluvial transport) [46]. Environmental pollution by these groups of organic compounds has received considerable attention as a result of public awareness towards environmental problems and expectations for good quality of life [13]. 

Bubb, J.M. and J.N. Lester. 1996. Factors controlling the accumulation of metals within fluvial systems. Environ. Monitor. Assess. 41 87-105. 

Relatively low permeability alluvial soils (silt, clay, and sandy clay), which corresponds with perching layers or aquitards. These soils were interpreted to be deposited in a low-energy, suspended load, fluvial-deltaic environment outside of channel zones. 

The Athabasca sedimentary Basin consists of Helikian polycyclic, mature fluvial to marine quartz-rich sandstone deposited in a near-shore shallow shelf environment (Ramaekers 1990) with an estimated filling beginning at about 1700 to 1750 Ma (Armstrong Ramaekers 1985). The estimate maximum thickness of the basin was 5 to 6 km from fluid inclusion studies (Pagel 1975). 

Power G, Power M (1995) Ecotones and fluvial regimes in arctic lotic environments. Hydro-biologia 303 111... 

Formation of Pyrite. Iron is carried to the peat swamp, before seawater transgression, as ferric oxide and hydroxides adsorbed on fluvial clays (123). During early diagenesis in a reducing environment, ferric iron is reduced to ferrous, which reacts with hydrogen sulfide to form iron monosulfide. If the basic mechanism of pyrite formation is similar to that in marine sediments... 

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