considerable information exists in the literature showing that expansive layer silicates are not the only clay minerals present in vertisols. however, the presence of a very high clay content dominated by fine clay, regardless of the clay type, together with the wetting and drying cycle in the soil can also produce a high shrink-swell potential. we studied some vertisols with diverse parent mat...

The yearly nutrient supply from land and atmosphere to the study area in SW Kattegat is 10 900 tons of N and 365 tons of P. This is only few percent of the supply from adjacent marine areas, as the yearly transport through the study area is 218 000 tons of N and 18 250 tons of P. Yearly net deposition makes up 1340 tons of N (on average 2.5 g m yr) and 477 ton of P (on average 0.9 g m yr). Shal...

water resources throughout human history have always been an important factor in attracting human settlement. the main purpose of this paper was to investigate what is the role of shadchay river in the location of two prehistoric settlements that are called tepe meymon abad. in this research by field studies and also to investigate the characteristics of the sediments, samples were taken from t...

the spatangoid genus schizaster agassiz is recorded, for the first time, from the lutetian (middle eocene) deposits of sargaz area, south of kerman, iran. the lutetian sediments of sargaz region contain a rich and divers echinoid fauna represented by cidaridae, conoclypeidae, echinolampadidae, toxopneustidae, phymosomatidae and schizasteridae. schizasteroid echinoids are an important component ...

The present study aims at evaluating the impact of diatoms and copepods on microbial processes mediating nitrate removal in fine-grained intertidal sediments. More specifically, we studied the interactions between copepods, diatoms and bacteria in relation to their effects on nitrate reduction and denitrification. Microcosms containing defaunated marine sediments were subjected to different tre...