DAR­WIN ROCKS

Weekend Argus (Saturday Edition) - - JELLYBEAN JOURNAL -

THE DAR­WIN Trail Map pro­vides in­sights into im­por­tant nat­u­ral sites in our city and gives us a sense of how those sites made an im­pact on him.

One of the places which made a huge im­pres­sion on him is the Sea Point Con­tact – a stretch of rock where lay­ers of gran­ite and sed­i­men­tary (clay) rock con­nect.

Be­fore Dar­win came along, most peo­ple thought rocks were formed un­der wa­ter mil­lions and tril­lions of years ago. Dar­win was in­trigued by the rocks at the Sea Point Con­tact, which look like they have melted into each other and blended.

He thought about the ori­gins of those rocks – and how they got to be like that. To say they had sim­ply got like that un­der the sea didn't ex­plain why they seemed all mixed up.

He sug­gested that a “cat­a­strophic ge­o­log­i­cal event” (a vol­cano, an earth­quake?) had shaped the way the rocks fused and made con­tact with each other. He thought that there may well have been a se­ries of events, so that the for­ma­tion of rock had built up and evolved over time.

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