Abstract: The present invention relates to a system for automatically recovering the entirety of the excavated materials in the order in which they are raised to the surface.The excavated materials being delivered through the central passage of a double pipe system pass into a strainer pipe 6 discharging into a perforated recovery sheath 5 which is closed at its base. A decompression sleeve 3 encloses the strainer pipe. Air and water are evacuated through the strainer slots 6 and all the excavated materials are deposited at 5 in the order in which they are brought up.The invention is applicable to any reverse circulation drilling system.