208 



Report of the State Geologist. 



In some parts of the beds, there is an almost entire absence of clayey or 

 other matter except the salt, while in other parts they predominate, and 

 irregular masses and layers of shale and limestone of considerable extent 

 occur. 



In the Livonia shaft this lower salt bed is overlaid by eight feet of 

 stratified rock. It is soft shale or marlyte at the bottom, but the upper part 

 is a thinly laminated impure magnesian limestone. 



Both the shale and the limestone are full of seams and veins of salt, 

 usually pink or red, and frequently in the larger veins it has a columnar 

 structure. 



Next above the limestone is the bed of stratified salt in which all of the 

 lour salt mines are situated. It is the lower part of the upper bed in the 

 western part of the district, and appears to have been deposited in quiet 

 waters. The lines of bedding are quite distinct, and may be traced for long 

 distances, the shaly matter and the gypsum having been deposited with the 

 thin layers of salt in varying proportion, or not at all. 



Non-continuous layers of limestone or shale several inches thick some- 

 times occur, but they are not common, and the whole amount of impurity in 

 the stratified salt is probably not more than 2 or 8 per cent of the "whole bed 

 The crystals are much smaller than those in the "mixed salt 11 and vary 

 considerably in size in different layers. Above the stratified salt, a layer or 

 mass of mixed salt occurs of the same character as that below. 



The contact line between these two beds is exceedingly uneven and is 

 only marked by a change from the laminated to the mixed condition of the 

 material. 



It is probable that the bed of stratified salt was orginally much thicker 

 than now, and that before it had become thoroughly hardened the upper 

 portions were broken up by the action of the waves and re-deposited in a 

 mixed condition, the disturbance of the layers reaching to greater depths at 

 some places than others. 



Distributed through this upper layer are masses of rock, generally com- 

 posed of gypseous shale and containing more or less salt in fine grains. 

 When a fragment of this rock is placed in water or exposed to damp air the 

 salt is dissolved, and soon there remains only a quantity of greenish or bluish 

 clay or dust and small particles or flakes of gypsum. 



Irregular and non-persistent layers of hard dark magnesian limestone also 

 occur, especially toward the top of the bed. They sometimes have a thickness 

 of two or three feet and appear to have been formed above the salt and to 



