Stylolites: Their Nature and Origin

Stylolites are defined on the basis of grain fabrics and classified on their geometry and their relationship to the bedding plane. Microscopic study of stylolites from several units from differentlocalities shows the following features to occur near or within thestylolitic seams: concentration of insoluble residues, dissolution, recrystallization, grain growth, grain orientation, pressure twinning, pressure shadows, microfaulting and shearing, cavity filling, and geopetal features. Most stylolites are herein interpreted to be diagenetic features initiated during the early burial stage and ending upon the complete elimination of pore space by drusy mosaic carbonate. Tectonically produced stylolites are considered to be the result of pressure solution and recrystallization due to physical factors rather than to chemical factors.