Geophysicist Sheldon Breiner will give a free presentation in Portola Valley's Historic Schoolhouse at 7:30 p.m. Tuesday, May 3, on his use of a handheld magnetometer to discover stone artifacts from the Olmec civilization buried for 3,000 years in the rain forests of southern Mexico.
Go to this link for more information. The Historic Schoolhouse is located at 765 Portola Road.
A magnetometer notes anomalies in the Earth's magnetic field caused by underground minerals that have or do not have magnetic properties. Any interruption in the profile of those minerals indicates the presence of something significant, such as a huge buried stone.