The formation occures near sea coasts on flat sedimentary rock that has been cracked.water wears away the rock in one of the two areas, either the rock or the cracks.
The pavement takes two forms, Pan or Loaf formation.
The pan formation is made of a series of concave depressions in the rock that typically forms beyond the edge of the seashore. As a result, this part of the pavement dries out more at low tide than the portion abutting the seashore and allows salt crystals to develop further, resulting in salt forming on the surface, which erodes the surface more quickly than at the joints. As a result, the surface of the “pans” erode more quickly, while the joints erode more slowly.
The loaf formations occur on the parts of the pavement closer to the seashore, and as a result, are immersed in water for longer periods of time. These parts of the pavement do not dry out so much, reducing the level of salt crystallization. Water carries abrasive sand and is channeled through the joints, resulting in the joints eroding faster than the rest of the pavement, resulting in loaf-like structures protruding.
Hydrolysis takes place when acid rain reacts with rock-forming minerals such as feldspar to produce clay and salts that are removed in solution. The only common rock-forming mineral that is not affected is quartz, which is a chemically resistant mineral. This is why quartz and clay are the two of the most common minerals in sedimentary rocks. Through presipitation quartz builds up in these cracks and start crystalizing, over time this process will completly fill the crack giving the effect of grout inbetween the tiles in your house.
When arriving at GZ you will find one of the two formations.
On site questions.
#1 Is it a pan or loaf formation?
#2 What colour is the formation?
#3 Measure the "pans" or "loafs" in width and give a average size.