Abstract: Rainfall runoff collection in ephemeral streams is an objective in semi-arid zones. Rack intake systems are proposed to collect these flash floods with intensive sediment transport. The design parameters address the problem of clogging the spacing between bars. Experiments for two different void ratio racks are shown. Flows, longitudinal slopes in the rack, and water with three gravel...

A first evaluation of the sedimentary changes, including accumulation of inorganic and organic carbon on the upper slope off Southeastern Brazil under different climatic conditions, based on the analysis of a sedimentary core, is here presented. Results indicate that sedimentation rate as well sedimentary characteristics, including the nature of the organic carbon deposited during the LGM (Last...

Heterogeneous pyritaceous-polymetallic and copper-zinc-pyrrhotine deposits on the South slope of the Greater Caucasus are located in the Lower-Middle Jurassic terrigenous sediments. They were formed under a wide variation of physico-chemical parameters of mineral formation and are characterized by specific mineralogical-geochemical peculiarities. Ore-formation occurred in three stages. In the f...

Fluid pressures in Miocene-Pleistocene sediments of the US mid-Atlantic continental slope approach the lithostatic stress and are an important control on the stability of the slope. Fluid pressures in excess of hydrostatic were generated by regional depositional patterns and sedimentation rates. Fluid migration within porous and permeable Miocene silty sand layers redistributed pressure and gen...

biofacies and palaeoecology of the limestone of the jahrum formation in the lar area in the southwest of iran (zagros basin) is addressed in this paper. our detailed analysis of biofacies and palaeoecology shows that the jahrum formation in the studied area were deposited in a carbonate open shelf dominated by heterozoan and, subordinately, photozoan skeletal assemblages. based on analysis of l...

Concentrations of copper, arsenic and cadmium in sediments and soils deposited on the flood plain of the upper Clark Fork River drainage were determined to be one to two orders of magnitude greater than in soils from typical noncontaminated systems. Aerial deposition of metal particulates during the period of smelting activities (1884-1980) has contributed approximately 2% of the excess copper,...

between the lower and upper cretaceous there were some diastrophic movements, belonging to the austrain phase. these movements, which can be traced in many parts of north and central iran, caused extensive precenomanian erosion. even in southwest iran a wide spread discontinuity is reported at the base of the kazhdumi formation, which is possibly related to these movements. in the kopet - dagh ...

In recent years, several studies have reported the successful extraction of ancient DNA (aDNA) from both frozen and nonfrozen sediments (even in the absence of macrofossils) in order to obtain genetic "profiles" from past environments. One of the hazards associated with this approach, particularly in nonfrozen environments, is the potential for vertical migration of aDNA across strata. To asses...

The pentacyclic tritcrpene 17/3(H),2 1 P(H)-hop-22(29)-ene (diploptenc) occurs in sediments throughout the Columbia River drainage basin and off the southern coast of Washington state in concentrations comparable to long-chain plantwax n-alkanes. The same relationship is evident for diploptene and long-chain n-alkanes in soils from the Willamette Valley. Microorganisms indigenous to soils and s...