The annual floods are very useful because they leave behind lots of sediments, material, debris...
When there's floodings, the water drags with it tons and tons of all sorts of sediments, material, debris, which after the water is retraced in it's river bed is left on the soil that has been flooded. So the soil gets lot of useful depositions which make her very fertile every year and extremely suitable for growing plants, this is the way in which alluvial soils are formed.
<span>Fossils symbol and mountain belts are very important
for geologists in deciding where to move the continents.
Fossils and mountain belts can give the
geologist ideas about the history of the certain continents and what are the
animals that stayed and died in that place.
Both can also help the geologists to identify if the particular continent is a
safe place to live on because the animals of a long time ago stayed on that
place. So maybe the place is safe from water high tide and is not a moving
plates.</span>