Limestone quarry.

During this measurement, it was necessary to determine for further mining areas with quality and lower quality limestone, which is not suitable for further economic processing. In addition, there were a number of cavities in the quarry, and these should be kept in mind when deploying blasting charges. It was measured with 3 m antennas with a central frequency of 50 MHz, the antennas were pulled behind the car.

The yellow wide column without reflections is a soft rock similar to siltstone. Harder rock is more soluble and a number of cavities are formed in it, these are reflections in the shape of inverted hyperbolas. It is good to see the oblique interface of two types of limestone going right down. Many more cavities are concentrated below it. In the area at the top right, sloping layers in the rock are visible.

There are very large cavities at the interface below. The left scale is for the speed of the wave in the air, from the differences of values it is possible to determine approximately the height of these cavities.

In the middle part again rock unsuitable for mining.