Flying pines, seepage and iron bacteria

This little path takes us straight to the Calvary Mountain. If you look closely, you can see a lonely pine tree standing here. This is a spontaneously seeded pine and is therefore also called a flying pine: the seeds have been blown here. Sometimes such a tree can develop beautifully in all directions.

In the vicinity, we see something that looks like a small pond. The water is rusty brown and there is an oily film floating on the surface. This appears to be oil, but when we poke it with a stick, the film breaks apart into polygonal shapes and, unlike oil, does not stick together.

These are iron bacteria that ensure that the iron in the water gets oxidized. These bacteria need iron, of course, but can only develop in stagnant water that rises from the underground. This is called 'spring water'. Probably, the water here is drained from a higher location and follows the impermeable Diestian iron sandbank from which the Calvary Mountain is made, up to where it nearly crops out at the flank in the open air.

Jan Rymenams