Figure 4-1. Conventional equipment for routine rock sawing. 



sufficiently coherent for sectioning without impregnation. Routine impregnation 

 of coherent rocks, however, may be desirable to preserve delicate features that 

 sawing and grinding might otherwise destroy. Canada balsam, Dammar gum, 

 Lakeside No. 70 cement, and various cold-setting plastics may be used. Satis- 

 factory results usually require special treatment such as replacement of hot 

 xylene with the impregnating medium by first moistening the specimen with 

 kerosene (Von Huene, 1949) or by impregnating in a vacuum. 



Thin-section data are often desired from uncored wells. Thin sections can 

 be prepared from cuttings without the sawing required with core thin sections by 

 mounting the cuttings directly in cement on a glass slide and then grinding to 



61 



