It is not, for instance, probable that sediment was deposited during the whole of the glacial period near the mouth of the Mississippi, within that limit of depth at which marine animals can best flourish:
Hala ere, dudatan jar daiteke munduko alderen batean, aldi honetan guztian zehar, inguru berean metatuz joan ote den sedimenturik, hondakin fosilak ere barne.