Macro and micro fabrics in chalk identified using the Bushinsky Oil Technique: an updated method and new applications for an old experimental technique

The Bushinsky Oil Technique was first described as a laboratory method to identify textures and fabrics in Russian Cretaceous chalk rocks in 1947. This method was later updated and adapted for use on Cretaceous chalk in the Anglo-Paris Basin in 1981. Light machine oil was brushed onto the samples and as it dried the chalk textures and fabrics became visible. Both of these methods were limited as they could only be carried out successfully on prepared slabs under laboratory conditions and results were temporary. Advances and adaptations to the technique using a specialist water resistant silicone lubricant mean it is now simpler, less time consuming to use, and the results are instant and semi-permanent.

Microfracture surveys conducted on orientated laboratory samples which had been prepared using the updated Bushinsky Oil Technique were compared with field scanline survey’s and the results showed a strong correlation between the two data sets. The results illustrate the relationship of textures and fabrics at different scales in chalk and demonstrate the value of the Bushinsky Oil Technique in exposing otherwise hidden features.