"Boudinage" in the High-Ardenne slate belt (Belgium), reconsidered from the perspective of the "interboudin" veins

The origin of the "boudins" and the associated "interboudin" veins in the H igh-Ardenne slate belt (Belgium) has always been a matter of controversy. T he question is whether or not they are the result of the process of boudina ge. Based on geometric, microthermometric and geochemical data, we suggest a close temporal relationship between slaty-cleavage and vein development, placing the origin of the "boudins" and "interboudin" veins entirely during the Variscan compressional event. Microthermometry of the fluid inclusions in the "interboudin" veins allows constraining P-T conditions, which vary between 255 and 145 MPa at 500 degrees C. (C) 2000 Elsevier Science B.V. Al l rights reserved.