deletions | additions       diff --git a/untitled.tex b/untitled.tex  index a041184..dd4d144 100644  --- a/untitled.tex  +++ b/untitled.tex 
...
  (iv) The calcites exhibit zoned development characterised by cyclic and pulsed evolution of precipitation temperatures and fluid compositions as a result of varying mixing ratios of the two fluid end-members.    (v) The fluids have high temperature fluid end-member has  evolved under low fluid:rock ratios. ratios and is in apparent equilibrium with the silici-clastic basin fill.    Simple thermal considerations indicate that fluid flow was episodic and highly focussed along the fault plane. We conclude that rising pore fluid pressures as a result of rapid sedimentation, hydrocarbon generation and silicate diagenesis  coupled with increasing tectonic stress as the basin inverted during the Variscan orogeny led to fault movement and release of the pore fluid pressure as the sediment pile dewaters. As with the example of the upper Mississippi Valley sedimentary basins the dewatering is episodic with extended periods during which the  pore fluid pressure increases increases. These periods are  punctuated by short periods duration episodes  of fluid release. Thisprocess  resembles very closely a seismic valve type process in which rising pore fluid pressure reduces the effective stress on fault surfaces, ultimately leading to failure and the formation of a high permeability path along which the pore fluid is released and the pressure dissipated  \citep{Sibson_1981}. \section{Geological setting of the Variscan faults and vein fill}