An earthquake measuring 6.0 on the Richter scale jolted 11km west of Tecpan de Galeana in Mexico at 07:36:01 GMT on Saturday, the U.S. Geological Survey, monitored here, said. The epicenter, with a depth of 23.0 km, was initially determined to be at 17.2304 degrees north latitude and 100.788 degrees west longitude.