Sedimentary sound. For rock lovers.
Sedimentary rocks are formed when mineral sediments and organic matter cement together. The place of deposition of the geological detritus is relevant to the process of rock formation. Minerals are transported by wind, ice and water, the agents of denudation.
Biological detritus is made up of dead aquatic creatures piling up on top of each other in underwater environments. Geological detritus is the result of rock erosion and weathering.
Biochemical sedimentary rocks are created by organism deposition, eg limestone which is formed from the calcareous skeletons of corals, mollusks, and foraminifera. Coal is formed from compressed vegetation that undergoes chemical transformation, and chert from the accumulation of siliceous skeletons of radiolaria and diatoms.
At tumulus and burial mounds in Europe some of the huge slabs of stones used in the construction of the chambers contain fossils, such as the stones at Stoney Littleton long barrow in Somerset, England. Huge fossils are inlaid in rocks placed at the entrance.
When I wrote this poem I could see the similarity of the fern-like uncurling of the fossils with the shape of the human ear. I used the word conch shell, then later found out the inner part of the ear is called the conch.
The science of archeoacoustics measures the sound frequency at archeology sites. The sound is measured in hertz, and the level in a chamber in West Kennet long barrow in Wiltshire, constructed 3670 to 3635 BC, is 84hz, which is the same as the open lower E string of the guitar. At the entrace 110 hz has been recorded, note A.
The notes E and A form the musical interval the ‘perfect fourth’, which mathematically is a ratio of 4:3, which is also found in architectural structures, and in the construction of other burial chambers found in the English landscape. Infrasound is also present, sounds too low to be detected by human ears, that nevertheless affect our bodies and brains, creating supersensory feelings and an awareness of not being alone. When drums are used, trance states can be achieved.
Where I grew up, the local rock is sandstone and there is an old quarry, now returned to woodland. A fossil footprint was found here in 1838 by quarry workers excavating 60ft below the surface, of a prehistoric reptile, a cheirotherium, which means ‘hand creature’. Incidentally, the sandstone from this quarry was used to clad the Empire State building in New York which was constructed 1930-31.
In my poem I also mention human footprints. In 2013 a set of fossilised hominid footprints dated 850,00-950,00 years ago, the early Pleistocene, were discovered on a beach in Norfolk, England. After stormy weather layers of sediment covering the footprints was washed away, thus they were revealed millenia after their creation. Alas, within 2 weeks the footprints themselves had been washed away by the tide. They are the oldest known human footprints found in Europe.
The background to the poem is textile art I created a while back and is part of the geology of my own life’s history.
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