Dysartian
Iron-Banded Sandstones
I found these Scottish sandstones interesting, because the beautiful colours are formed by two different types of iron oxides, which I have rarely seen together. In its natural state Iron is a silvery grey colour, but it oxidises (rusts) too easily to remain pure for long. The Ferric iron (Fe III) ranges in colour from yellow to black, although orange-red is most common, whilst in contrast the Ferrous ion (Fe II) tends to give a greenish stain to rocks. The dark red ironstone bands in this shot appear to surround strange sedimentary structures and being harder than the sandstones tend to have been left in relief as strange ring-like shapes. The white grains you might spot are actually snow. I think geology can be wonderful, but then for me being a rock-jock, rocks really do rock.
By the way, I later found the rings are called Liesgange Bands and are post-deposition diagenetic structures that cut across sedimentary banding
Iron-Banded Sandstones
I found these Scottish sandstones interesting, because the beautiful colours are formed by two different types of iron oxides, which I have rarely seen together. In its natural state Iron is a silvery grey colour, but it oxidises (rusts) too easily to remain pure for long. The Ferric iron (Fe III) ranges in colour from yellow to black, although orange-red is most common, whilst in contrast the Ferrous ion (Fe II) tends to give a greenish stain to rocks. The dark red ironstone bands in this shot appear to surround strange sedimentary structures and being harder than the sandstones tend to have been left in relief as strange ring-like shapes. The white grains you might spot are actually snow. I think geology can be wonderful, but then for me being a rock-jock, rocks really do rock.
By the way, I later found the rings are called Liesgange Bands and are post-deposition diagenetic structures that cut across sedimentary banding