: a minute tektite one millimeter or less in diameter found especially in sediments on the ocean floor.

What is a Microtektite?

Tektites and the smallest versions called microtektites are glassy spherules of terrestrial crustal material that formed as melted-and-quenched debris from natural, hypervelocity impacts. And only four major strewn fields of tektites and microtektites have been identified worldwide. ...

What type of sediment are Microtektites?

Microtektites have been found so far only in deep-sea sediments, probably because of the difficulty of distinguishing them in the more abundant and coarser land sediments. They are distinguished from volcanic ash by their rounded shapes and composition, which is identical with that of the large tektites.