Noun
volcanic ash (usually uncountable, plural volcanic ashes)
(geology) Fragments of pulverized rock, minerals and volcanic glass created during a volcanic eruption.
Agriculture Fava Santorinis Because of its unique ecology and climate, and especially its volcanic ash soil, Santorini is home to unique and prized produce. Source: Internet
Amorphous clays Amorphous clays are young, and commonly found in volcanic ash. Source: Internet
Dating of lava and volcanic ash layers found within a stratigraphic sequence can provide absolute age data for sedimentary rock units which do not contain radioactive isotopes and calibrate relative dating techniques. Source: Internet
Fortunately, in the Oman sequence, so too does a volcanic ash horizon from which zircons provide a very precise age of 541 ± 0.3 mya (calculated on the decay rate of uranium to lead). Source: Internet
Radioactive elements are common only in rocks with a volcanic origin, and so the only fossil-bearing rocks that can be dated radiometrically are volcanic ash layers, which may provide termini for the intervening sediments. Source: Internet
Potential for additional productivity from fallow land was questionable, however, because much of Honduras's soil lacks the thick volcanic ash found elsewhere in Central America. Source: Internet