Gold, geography and the patterns of Aboriginal life

When I was a kid, I was fascinated by the stories of gold, of people who had struck it rich, as well as those who had failed.

I grew up in a mining area. Gold, silver, antimony, sapphires, diamonds, tin; the remains of mines and mining equipment littered the landscape. The old caretaker still guarded the now decaying plant of one of the bigger mines even though he had not been paid for many years. It just seemed right to him to do so.

Fortunes were indeed made from mining, but so were large sums lost as people searched for the elusive mother lodes within the twisted geography and geology of the area. This is a world turned upside down; sea beds can be found on high plateaus; streams that once flowed west to join the inland rivers were forced to turn east as continents split and the land rose; giant volcanoes spewed basalt across the landscape.

When the Europeans first came to this area, they were puzzled by the landscape. European settlement took place at a time of great intellectual curiosity. The puzzles and answers offered by this landscape played an important role in the advancement of geological and geographic knowledge.

Today, I am still fascinated by mining stories. However, now I am trying to understand the landscape for different reasons. Just how did it evolve? How does it link to the patterns of human life over the millennia?

The remains of an old Pleistocene shore line uncovered by a fierce storm millennia ago becomes an Aboriginal industrial site only to be covered again and then uncovered. Rising water levels submerges the coastal plains that then re-appear as deposition from coastal streams forces the coastline east again. But what were the actual changes? How do we map them?

The biggest puzzle to my mind in the human history of this landscape is just how recent Aboriginal settlement appears to be in human terms. More precisely, nearly all the dates we have from the various dating techniques are much younger than we might expect from dates in other areas.

We know from ethnohistorical evidence that the coastal strip and especially the Northern Rivers was a very wealthy area with very high Aboriginal populations. Just to put this in perspective, the Aboriginal population of the Northern Rivers was probably far higher, maybe as much as ten times, than the Aboriginal population of all the western deserts and arid zones combined. Yet the dates don't seem to reflect this.

Part of the answer may simply lie in accidents of preservation and discovery. Increasingly, however, I am coming to think that the answer lies in the combination of geography with climate change. The very high value coastal environments may in fact be quite recent. For the moment, that is just a guess, but it is one worth testing.