Premium
Fracture sealing of quartzite under a temperature gradient: experimental results
Author(s) -
Hilgers Christoph,
Tenthorey Eric
Publication year - 2004
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/j.1365-3121.2004.00545.x
Subject(s) - geology , quartz , fracture (geology) , electron microprobe , lithology , hydrothermal circulation , vein , temperature gradient , seal (emblem) , mineralogy , microprobe , petrology , geotechnical engineering , seismology , paleontology , psychology , quantum mechanics , psychiatry , art , physics , visual arts
Veined lithologies are formed by fracturing and sealing processes, with the veins representing former fluid conduits through the rock. Although detailed fieldwork and numerical simulations have provided a better understanding of vein growth, few studies have attempted to seal fractures and generate veins experimentally. In this pilot study, we subjected fractured quartzite to temperature gradients of 45–125 °C under hydrothermal conditions in a static fluid, with the aim of precipitating secondary quartz in the cooler portions of the fracture. Results show that secondary quartz precipitates due to the imposed temperature gradient, causing the initial fracture to seal locally. Although no systematic sealing pattern was observed along the fracture, samples subjected to higher temperatures exhibit a smaller fracture width and appear to have reacted more extensively. Electron microprobe mapping visualizes the spatial distribution of secondary quartz, which contains elevated concentrations of aluminium.