For more than one million years, naturally occurring basalt rock spheres have been used by hominin species as a type […] ...

A new study by Dr. Margherita Mussi, published in Quaternary International, highlights how naturally occurring basalt spheres ... Margherita Mussi, The volcanic rock spheres of Melka Kunture ...

Folgheraiter, on the magnetism induced in volcanic rocks by the earth's magnetic field ... The specimens of basalt examined may be divided into two groups: in the first may be placed those ...

which gives us a clue as to the volcanic origin of this type of rocks Some inquisitive geologists started asking questions about our granite and basalt rocks. Both are igneous. The word igneous ...