## 3 Materials and Methods
### Methodology of Dataset Analysis
#### 3.2.2 Analysis of Structural Elements  
The characteristics of the structural elements included the mentioned layering and fractures. They were documented in order to recognize their relationship with the morphology of the hydration forms (their elongation, orientation of entrances).  
The strike and dip of the gypsum-anhydrite layers were measured directly in the quarry, and the strike of the layers visible in the bedrock was traced and documented as lineaments on the orthophotomaps in the ArcGIS program (Esri, Redlands, CA, USA).  
Similarly, the fractures were both measured directly and traced using the orthophotomap in the ArcGIS program (Esri, Redlands, CA, USA). Attention was paid to fractures showing the features of systematic joints and master joints [98]. Traces of such fractures or joints were recognized on the orthophotomap and marked on areas of the quarry where they were best seen. The tilt value of these structures was assumed to be vertical or nearly vertical, based on the direct field measurements and observations. Joints and fracturesmeasured in the quarry were analyzed on Angelier diagrams, whereas joint traces on the quarry bottom were characterized on rose diagrams [99]. The rose diagrams (in the ArcGIS program using polar plots), unlike the traditional ones, took into account the length of the fractures, which translated into a more realistic analysis. The description of the fractures was based on the terms and classifications presented by [PERSON] et al. [100].  
To characterize the deformation a rock has undergone to give convex hydration forms, we attempted to determine the direction of the maximum lateral (horizontal) expansion (or extension) within this surface layer (Figure 3) in a similar way as [PERSON] and [PERSON] (Figure 9 in [66]) designated the direction of extension in A-tens (see also [65]). The maximum lateral expansion (MLE) was marked as normal to the line of the crest of the form. The wavy-shaped crests were approximated to straight lines and MLE was assumed to be normal to this line. In many cases where precise determination of the direction of the MLE was difficult or impossible, it was marked arbitrary. The relations of MLE to elongation of the forms were investigated by determining the angles between both directions.  
Attention was paid to the fractures occurring on the surface and in the vicinity of the hydration forms. Their orientations were measured to reveal the influence of master joints on the development of fractures within hydration forms and in relation to the direction of MLE [85]. The intersections of fractures were studied to determine the order of their generation [100; 101]. In addition, the surface density of fracture traces [102] in 3D space, \(\mathrm{F_{D}}\), was calculated for every form according to the modified formula [85] and similar to the trace density formula [86]:  
\[\mathrm{F_{D}}=\frac{\Sigma\mathrm{Ls}}{\mathrm{P}} \tag{4}\]  
where:  
\(\Sigma\mathrm{ls}\)--sum of the length of the fracture traces within the hydration form surface measured in 3D (m)  
P--surface area of hydration form (m\({}^{2}\))