Molasse or mollasse?

The spectacular cliffs of Aiguebrun are made of sandy limestone (which contains grains of sand) biodetrital (which also contains various fossil debris). Locally, it is called molasses or mollasses according to two possible etymological origins: mola = grindstone, because this abrasive rock was used to produce grindstones. Or mollis = soft, because the rock can be sharpened and be cut easily. This is the noble stone of the quarries of Provence.