Murphy's Haystacks

Murphy's Haystacks are inselberg rock formations located at Mortana, between Streaky Bay and Port Kenny on the Eyre Peninsula in South Australia.^[1]

The overhanging dome formation is approximately 8 metres (26 ft) high.

Murphy's Haystacks

They are of a 'tumulus' form of weathered granite outcrop.^[2] They are made of a pink, massive, coarsely equigranular rock consisting mostly of quartz and orthoclase. Their appearance may be due to a combination of erosion by underground rainwater and then by subsequent weathering after they were exposed. Most of the pillars emerge without a break from the underlying granite. Their structural base may be of orthogonal or vertically-aligned sheet jointing.^[3][4]

They obtained their name because a traveller in a coach saw the formation in the distance. He asked how a farmer could produce so much hay. As the farm was on a property owned by a man called Murphy, the rocks became known as Murphy's Haystacks.^[5][6]

The site is listed on the South Australian Heritage Register.^[7]

Reverse side of the formation