Abstract:

          The  initial  thicknesses of  the original  rock  layers can be  restored by various  fish head boudins. Furthermore, we
can analyze the linear strain in Z and X axes of the strain ellipsoid of the original rocks by the layer thicknesses. In this article,
a method  for estimating  the viscosity  ratios of adjacent competent  layers was derived  from  the Strain Differential Refraction
Rheology Gauges. An application  trial was made  for  two specimens of  fish head boudins  from  the Tieshan area, Daye, Hubei
province. We obtained the viscosity ratios of two adjacent fish head boudin hornfels layers in marble matrix, which are 3.07 and
0.75, respectively.

Key words:  fish head boudin, initial thickness, strain refraction, competency