Spatial Statistical Properties of Pressure Solution Seams in Clastic Rocks in Southwest Ireland |
| |
| Authors: | Filippo Nenna Xiaoxian Zhou Atilla Aydin |
| |
| Institution: | (1) Rock Fracture Project, Department of Geological and Environmental Sciences, Stanford University, Stanford, CA 94305, USA |
| |
| Abstract: | Length, height, thickness and spacing measurements of pressure solution seams at outcrop, hand sample and thin section scale were taken from clastic rocks located in the southwest of Ireland. The lengths and spacings of pressure solution seams have similarly shaped (approximately log-hyperbolic) distributions at the observed scales suggesting that length and spacing distributions are scale-independent over the scales studied with a fractal dimension in the range of 1.4 to 1.6. Pressure solution seam lengths and thicknesses are related by a power-law and their spacings have a linear relationship to bed thickness. Although pressure solution seams are often considered as anticracks (forming under the same remote stresses as joints, but with opposite sign) we describe how the mechanism of pressure solution differs substantially from that of jointing. We use an existing mechanical model to show that stresses around pressure solution seam tips are much lower than those for joints under equal but opposite loading conditions. Pressure solution seams also have a decreasing tendency to lengthen as they grow, which is reflected in their length distributions. We propose that pressure solution seams, unlike joints, do not reach fracture saturation spacing because of transverse coalescence. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
