On the maintenance of anomalous fluid pressures: II. Source layer at depth

Geological Society of America Bulletin
By:  and 

Links

Abstract

Physico-chemical mechanisms have been suggested to account for anomalous fluid pressures in the geologic environment which require a fluid source at depth. The persistence of anomalous pressure is a problem that involves nonsteady fluid flow. The hydrodynamics and particular boundary conditions control the time rate of pressure change and its maintenance. A series of mathematical solutions germane to the maintenance of anomalous pressure caused by the injection of fluids into the system from a source layer are presented. The phase change, gypsum to anhydrite plus water, is used as an example of a fluid source at depth. The thermodynamics of the gypsum-dehydration reaction indicates that conversion will probably occur at shallow depths and produce fluid at a constant rate. The dehydration of montmorillonite will also produce fluids at a constant rate under geologic conditions where the reaction can occur. If horizons of material of low permeability are missing or scarce, it is doubtful that anomalous pore pressures can be maintained for more than a geologic instant. The creation and continuation of anomalous pressure depend largely upon the hydraulic conductivity and, to a lesser extent, upon the specific storage of clay layers within the system. © 1968, The Geological Society of America, Inc.

Publication type Article
Publication Subtype Journal Article
Title On the maintenance of anomalous fluid pressures: II. Source layer at depth
Series title Geological Society of America Bulletin
DOI 10.1130/0016-7606(1968)79[1107:OTMOAF]2.0.CO;2
Volume 79
Issue 9
Year Published 1968
Language English
Publisher Geological Society of America
Description 16 p.
First page 1107
Last page 1122
Google Analytic Metrics Metrics page
Additional publication details