The shock exposure of the Santa Fe's impact structure in New Mexico is evidenced by large human-size shatter cones. A new magnetic mechanism allows a magnetic detection of plasma's presence during the impact processes.
Rock fragments from the impactites were once magnetized by a geomagnetic field. Magnetic level of remanence revealed more than an order of magnitude lower magnetizations in the rocks that were exposed to the shockwave.
A newly proposed mechanism is that the shock wave perturbation of magnetic stability plays in accord with the plasma magnetic shielding.