Piezonuclear reactions during mechanical tests of basalt and magnetite

Neutron emissions (NE) were measured during laboratory compression tests of magnetite specimens, loaded up to failure under monotonic displacement control, and of basaltic rocks during cyclic loading tests. In order to detect neutron emissions, the experiments were monitored by two different neutron detectors: He3 proportional counter and thermodynamic (bubble) detectors. After the tests, Energy Dispersive X-Ray Spectroscopy (EDS) analyses were conducted to recognize possible direct evidences of low energy nuclear reactions (piezonuclear reactions) on fracture surfaces. In particular, quantitative evidences of nuclear reactions, involving Fe decrease and the increases of lighter elements, have been observed in olivine, a crystalline phase widely diffused in the basalt chemical composition. These results confirm similar evidences previously observed on Luserna stone (granite) and confirm that piezonuclear reactions take place in iron-rich materials.