Experimental Investigation of Clogging of Fissures and Pores in Granite

A. C. M. Bourg, P. Oustrière and J. F. Sureau
Geochemical Processes Group, Département Gîtes Minéraux, National Geological Survey, BRGM, BP 6009, F-45060 Orléans Cédex, France

Abstract: Fluid flow through a fractured granite core and leaching experiments on granite powder (at constant temperatures of 50 and 100°C and during cooling from 100 to 50°C) indicate that the dissolved silica content of the fluids originates from the dissolution of feldspars and phyllosilicates. The dissolution of quartz is not ruled out but it should be a minor phenomenon. The precipitation of quartz may control the dissolved Si content during constant temperature leaching. During cooling from 100 to 50°C chalcedony, alumino-silicates, and chlorite are all capable of precipitation, possibly leading to some clogging or sealing of fissures.

Keywords: granite • fluids • fissures • silica

Mineralogical Magazine; April 1985 v. 49; no. 351; p. 223-231; DOI: 10.1180/minmag.1985.049.351.09
© 1985, The Mineralogical Society
Mineralogical Society (www.minersoc.org)