Abstract: Typical examples of cosmic ray irradiation effects in extraterrestrial materials have been introduced by two large iron meteorites, Campo del Cielo and Gibeon. The Gibeon meteorite is known for having the longest strewn field of all meteorites extending 400 km. Stable light noble gases were determined simultaneously by sensitive mass-spectrometers. Based on the contents of products determined, we have discussed an unique complex history of the meteorite. We could classify Gibeon meteorite as a mixture of two main sub groups. The members of the first group have a simple long irradiation history of 330 million years, which is similar to Campo del Cielo. On the other hand, those of the 2nd group are composed of the secondary products of various contents of noble gases showing irradiation records equivalent to an average of 20 million years. The reductions of noble gases were most probably due to a serious break up of the meteorite in space. The deep interior of the main body of Group 1 has been exposed by the break up, and a secondary irradiation forming the Group 2 started. The time of break up seems to compare well with the fairly constant exposure ages of chondrites.