The Land of Golden Coral

In Victoria, the site of Australia’s first gold rush, there exists spectacular underwater reefs inlaid with the precious metal. The exquisite formations, which have become known as the Bendigo golden reefs, have long puzzled scientists. Until recently, it was thought that molten gold rising through the earth’s crust was the source of the deposits, many of which haven’t been mined commercially. Instead, two Tasmanian researchers from the University of Tasmania have proposed that the gold is sources from two underwater mountain ranges. These ranges, which stretch from Tasmania to New South Wales, are over 450 million years old. Erosion and sedimentation into the rock sequence are likely to blame for the gilded coral reefs.

The two researchers looked extensively at the ocean floor, and how rocks and sediments are transported and deposited through natural phenomena. In the case of the golden reefs, it is likely that the precious metal slowly eroded away from the walls of the submerged mountains. Next, in a giant channel-levee complex—which is essentially an underwater river—the gold was deposited as sediment near the present day Bendigo reefs. Finally, fine layers of silt transported the gold to the coral reefs, where they eventually settled in large deposits, fueling the great Australian gold rush and creating a mystic underwater wonder.

A sample from the golden reefs

Source: ‪http://bit.ly/13XKDxN