Rocks of Time
Last Saturday I blipped Sands of Time. Today these are Rocks of Time.
This morning the sun shone and the sea was blue with a couple of boats offshore. Probably they were support boats for divers exploring the wonderful world under the water or maybe they were for sea anglers. But of more interest to us as we sat on the very steep grassy slopes at Siccar Point looking down on what is regarded as one of the most famous and important sites of global significance to scientists and geologists were the contorted rocks. Until the late 18th century it was generally believed that the Earth was about 6000 years old but the Scottish James Hutton in 1788 examined these gently sloping beds of red sandstone above vertical beds of rocks and proved that it was many millions of years old so confounding previous beliefs.
The vertical sediments at Siccar Point are Silurian greywacke, a grey sedimentary rock formed approximately 425 million years ago when colliding plates created immense pressure that converted the sediment to rock. The horizontal rocks were tilted and raised above land by pressure. Erosion had then worn away the above-ground parts of the vertical sediments, after which they were again submerged and covered by new horizontally deposited sediment. The younger gently sloping Old Red Sandstone rocks are about 370 million years old. Hutton was the first to realize that these processes are still ongoing, and that the Earth is continually being reshaped by forces that uplift rock, wear it away, deposit it as sediment, and compress it into rock again. His theory became known as Hutton's Unconformity.
To see a fuller explanation this.
The sea and the rocks below reminded me that our time on Earth seems a mere blip In Time.
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