English to Spanish Tech/Engineering Geology

Delta deposits occur at or just beyond river mouths. The essential condition for
growth of deltas is that the rate of deposition should exceed the rate of removal
by waves or currents. In a simple delta model, the river current loses its energy
where it meets the sea, depositing its bottom load in a fan-shaped deposit
(delta from the Greek letter Δ). The coarsest fractions are deposited first, with
finer and finer fractions increasingly further away from the mouth. As the delta
front advances, coarser fractions cover the finer fractions, thus forming layers
where grain sizes increases upwards (coarsening up; ***fining down***).

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