Dysartian
Liesegang Bands in Carboniferous Sandstones of Fife
BEST VIEWED ON BLACK? The area of rock shown is about five feet long by three feet high. The strange cauliflower structures are caused by iron-rich ground-waters passing through soft sands before they have been cemented into sandstone. The darker brown lines are made of iron oxide. The effect over a large area of rocks produces natural art. Each rock canvas differs from the outcrop next to it. The sandstones are at the top of The Upper Limestone Formation, Namurian (Carboniferous in age) and are about 320 million years old.
Liesegang rings (or Liesegang bands) are coloured bands of cement observed in sedimentary rocks that typically cut-across bedding. These secondary diagenetic sedimentary structures exhibit bands of authigenic minerals that are arranged in a regular repeating pattern. Liesegang rings are distinguishable from other sedimentary structures by their concentric or ring-like appearance. The precise mechanism from which Liesegang rings form is not entirely known and is still under research, however there is a precipitation process that is thought to be the catalyst for Liesegang ring formation (which is referred to as the Ostwald-Liesegang supersaturation-nucleation-depletion cycle). Though Liesegang rings are considered a frequent occurrence in sedimentary rocks, rings composed of iron oxide can also occur in permeable igneous and metamorphic rocks that have been chemically weathered.
Liesegang Bands in Carboniferous Sandstones of Fife
BEST VIEWED ON BLACK? The area of rock shown is about five feet long by three feet high. The strange cauliflower structures are caused by iron-rich ground-waters passing through soft sands before they have been cemented into sandstone. The darker brown lines are made of iron oxide. The effect over a large area of rocks produces natural art. Each rock canvas differs from the outcrop next to it. The sandstones are at the top of The Upper Limestone Formation, Namurian (Carboniferous in age) and are about 320 million years old.
Liesegang rings (or Liesegang bands) are coloured bands of cement observed in sedimentary rocks that typically cut-across bedding. These secondary diagenetic sedimentary structures exhibit bands of authigenic minerals that are arranged in a regular repeating pattern. Liesegang rings are distinguishable from other sedimentary structures by their concentric or ring-like appearance. The precise mechanism from which Liesegang rings form is not entirely known and is still under research, however there is a precipitation process that is thought to be the catalyst for Liesegang ring formation (which is referred to as the Ostwald-Liesegang supersaturation-nucleation-depletion cycle). Though Liesegang rings are considered a frequent occurrence in sedimentary rocks, rings composed of iron oxide can also occur in permeable igneous and metamorphic rocks that have been chemically weathered.