Presentation on theme: "RELATIVE DATING What is it ?. Who Dunit ? James Hutton Holyrood Park Edinburgh Castle Lets start with the story of James Hutton, a wealthy farmer born."— Presentation transcript:
RELATIVE DATING What is it ?
Who Dunit ?
James Hutton Holyrood Park Edinburgh Castle Lets start with the story of James Hutton, a wealthy farmer born in 1726. As a farmer, it brought him into close contact with the land
James Huttons Revelation He was the first person to realise that the Earth must have been very much older than the 6,000 years believed at that time
Huttons Imagination Hutton was convinced that the lowlands of Scotland had been made at a later time than the uplands, but he did not have any proof UNTIL …
Siccar Point, Nr Edinburgh Whilst walking along the beach at Siccar Point, he noticed that the pebbles had come from the cliff – he now understood that the beach sand was made from the eroding cliffs – that was a big leap of imagination for its time
Huttons Story of Siccar Point He then noticed around the corner from the beach that some gently dipping red sandstones were lying on top of some grey-coloured upright layers From his observations, he began to unravel the story of what had happened to these rocks
RELATIVE DATING PRACTICAL
So, what is Huttons Story ? The grey-coloured beds (A) were laid down as horizontal layers of soft muds in the sea. A These were hardened into rock deep in the Earth and then buckled into folds by immense stresses.
So, what is Huttons Story ? These stresses also thrust the rocks up to the surface as great mountains, which were then eroded. A These mountains were likewise worn down, and formed the horizontal red beds (B) on top of the vertical grey rocks. B
So, what is Huttons Story ? What is his evidence? Fragments of the folded grey rock (A) are found in the red beds above it (B) – so the red beds must be younger. B A A A A A He didnt even need fossils to date his beds !
Fold Shape ANTICLINE younger older SYNCLINE younger older What do you think produces folds ?