Source of Sydney Sandstone Solved.

24 August 2011

Every since I was a little child I wondered. What's the reason? I have lived in Sydney, Canberra and Scone. Every time we drove through the road cuttings travelling into Sydney I would look the swirls and layers in the sandstone and wonder about how all that sand was laid down. There is so much of it! I had seen it in the Blue Mountains, the South coast and up through the Hawksbury River crossing on the freeway. We enjoyed the sand at the beach when in Sydney for holidays with my cousins.

I remember a friend at Uni who was a creation scientist. He was also a geologist. He found the Sydney sandstone a real challenge to his view of a young planet only 6000 years or so old.

Recently, one of my most favourite episodes of Catalyst (Episode 15, 2011, found here) explained the mystery! Paul Willis explained that the sandstone stretches from Lithgow in the West, up to Newcastle and down to Nowra. The sandstone is all from an absolutely massive river estuary that covered that whole region.

Recent studies on the sands of Sydney and its region reveal that much of the sand and sediments started life in Antarctica, a billion years ago. A very large river came from what was the highlands of Antarctica, across Antarctica, and across from South Australia to Sydney. Antarctica and Australia were joined together as one – Gondwana. The journey along the river filtered out many things but left the cleaner, white, silica sand that we see in the sandstone.

The movement of that sand from the estuary region has produced the sand Islands of Southern Queensland. This includes Fraser Island, which is the largest sand Island in the world. We went there back in 1998 with friends.