The warp consists of fine muddy sediment which is suspended in the tidal river water and appears to be derived from material scoured from the bed of the Humber by the action of the tide and a certain amount of sediment brought down by the tributary streams which join the Humber some distance from its mouth.
This river, as well as the Amu, conveys vast quantities of sediment into the lake; the delta of the Syr-darya increased by 134 sq.
Ferguson has shown that the sediment is carried away from this area by the set of the currents; probably then it has remained free from sediment whilst the neighbouring sea bottom has gradually been filled up. If so, the thickness of the alluvium is at least 1800 ft., and may be much more.
The bottles, which up till now have been in a horizontal position, are then, in order to prepare them for the next process, namely, that known as disgorging, placed in a slanting position, neck downwards, and are daily shaken very slightly, so that by degrees the sediment works its way on to the cork.
The conditions favourable to the production of coal seem therefore to have been-forest growth in swampy ground about the mouths of rivers, and rapid oscillation of level, the coal produced during subsidence being covered up by the sediment brought down by the river forming beds of sand or clay, which, on re-elevation, formed the soil for fresh growths, the alternation being occasionally broken by the deposit of purely marine beds.
Of country, and carries its burden of sediment westwards.
This fermentation proceeds throughout the summer months, and in the meantime a sediment which adheres to the side of the bottle is gradually formed.
A particularly fine-grained mud is formed on the low coasts of the eastern border of the North Sea by a mixture of the finest sediment carried down by the slow-running rivers with the calcareous or siliceous remains of plankton.
Piercing the desert, and at its annual overflow depositing rich sediment brought from the Abyssinian highlands, the river has created the Delta and the fertile strip in Upper Egypt.
When the whole of the sediment is on the cork, the iron clip, with which the latter is kept in position, is removed for a moment, and the force of the wine ejects the sediment and cork simultaneously.