Microstructures grown experimentally from advectivesupersaturated solution and their implication for natural vein systems

The relevance of vein texture in understanding the past hydraulic behaviour of a crystalline rock mass: reconstruction of the palaeohydrology of the Mecsekalja Zone, south Hungary

“…3A,B). Vein occlusion in conjunction with a syntaxial texture is characteristic of advective transport and channelised flow (Lee et al 1996;Hilgers & Urai 2002b;Hilgers et al 2003). Cathodoluminescence image analysis reveals swarms of orange luminescent microveins ( Fig.…”

“…If the fluid is of metamorphic or magmatic origin, a temperature drop is implied, which is inconsistent with calcite precipitation, because the decrease in fluid temperature at constant salinity increases calcite solubility, and vice versa (Parry 1998). Isothermal precipitation is possible during decompression of fluid that is saturated with dissolved carbon dioxide (Parry 1998 Hilgers et al (2003). This process produces partially filled fracture systems, with decreasing filling with distance from the obstruction, because of a shift in saturation state along the flow pathway.…”

Implications of Pyrite Oxidation for Engineering Works

“…35). Hilgers et al (2003) showed experimentally that when cracks are infilled by the precipitation of calcium sulphate from a mobile solute, the larger crystals occur in the direction of the source liquid, with the crystals becoming smaller as the solute passing through the crack is progressively depleted (Fig. 36).…”

Post-metamorphic palaeofluid evolution of the Mecsekalja Zone metamorphic complex

“…healed microfractures (Milliken and Laubach, 2000;Laubach et al, 2004) (Machel and Burton, 1991;Machel, 2000). This textural stigma reinforce the interpretation that the parent fluid did not got to the site of precipitation by fracture This texture is indicative of advective flow (Bons, 2000;Passchier and Trouw, 2005;Bons 2001;Hilgers et al, 2003). The Qtz BL crystals contain one phase aqueous fluid inclusions, what indicates entrapment below 50 °C (Goldstein and Reynolds, 1994).…”

“…The grains' microscopic morphology is elongate blocky, what is a texture resulting from the so called growth competition, and indicates advective flow of the parent fluid (Bons, 2000;Passchier and Trouw, 2005;Hilgers et al, 2003). During advective flow, that can occur in fractures of several centimetres width in the studied veins, the degree of fluid-rock interaction is possibly low, since after precipitation occurs on the vein wall further interaction is ceased between the fluid and the host rock (Oliver and Bons, 2001).…”