Three-dimensional morphology and connectivity of stylolites hyperactivatedduring veining

The limestone of the Palaeozoic Jack Formation in north Queensland, Austral ia, contains bedding-parallel stylolites that locally increase in amplitude adjacent to calcite veins. The veins formed in response to inhomogeneous s train locally superposed on the tightly folded strata. Stylolites were loca lly hyperactivated during vein formation and provided calcite for vein fill ing. Three-dimensional reconstructions of the morphology of the stylolites, based on detailed serial profiles, demonstrate that the side-faces of colu mnar stylolites form an interconnected fluid pathway through the rock. The connective morphology defines a drainage network comprising highly tortuous major trunks of high amplitude side-faces linked locally by minor pathways of variable amplitude. The permeability pathway anastomoses in three dimen sions making it impossible to image in two dimensions alone. (C) 1999 Elsev ier Science Ltd. All rights reserved.