Dysartian
Rocking Beach Rock
I found this beautiful (2 feet by one foot by seven inch) boulder fragment on our local beach. The outside was rich chocolate brown and the inner layered sandy beds had these strange 'cauliflower' structures. These may have been formed by iron-rich groundwaters moving through the sand whilst the rocks were still in a soft bedded state. I'll have to ask my sedimentologist friends at the University of Edinburgh what caused this phenomena! Anyway I thought it was a pretty piece of natural art and that's what counts for me! Made Explore 31 May. My contact Subarctic Mike, recognised these as roll front deposits which are indeed symptomatic of unidirectional fluid flow through sandstones. This flow carries waves of minerals, which can include radioactive uranium. Indeed roll front deposits are one of about three different mechanisms that can concentrate commercial deposits of Uranium ore. Now where is my geiger counter?
By the way I wouldn't normally take any such rocks or even pebbles off the beach, because too much of this type of removal can aid coastal erosion. However this soft-ish rock would not have survived the winter storms! It now looks nice in my back-garden next to large pots of plants and exotic driftwood!
Rocking Beach Rock
I found this beautiful (2 feet by one foot by seven inch) boulder fragment on our local beach. The outside was rich chocolate brown and the inner layered sandy beds had these strange 'cauliflower' structures. These may have been formed by iron-rich groundwaters moving through the sand whilst the rocks were still in a soft bedded state. I'll have to ask my sedimentologist friends at the University of Edinburgh what caused this phenomena! Anyway I thought it was a pretty piece of natural art and that's what counts for me! Made Explore 31 May. My contact Subarctic Mike, recognised these as roll front deposits which are indeed symptomatic of unidirectional fluid flow through sandstones. This flow carries waves of minerals, which can include radioactive uranium. Indeed roll front deposits are one of about three different mechanisms that can concentrate commercial deposits of Uranium ore. Now where is my geiger counter?
By the way I wouldn't normally take any such rocks or even pebbles off the beach, because too much of this type of removal can aid coastal erosion. However this soft-ish rock would not have survived the winter storms! It now looks nice in my back-garden next to large pots of plants and exotic driftwood!