Last Sunday I joined a group of locals and two geologists to revisit sites I'd already scrutinised and theorised over. Having done my homework, I was entering a world that had become vaguely familiar. It was a delight to have the rock-story told fluently and coherently and a great relief to have the geologist's boot stomping on rocks he was talking about, and indicating on real rock the substance of his discourse.
A few snippets from that day
- I'm not the only one who has trouble imagining earth's time scale. 1 million years is about as far as the geologist can stretch: 500 million years is beyond even his capacity.
- Research into local geology, except for Bingie Bingie, is thin on the ground.
- Some of the rocks we encountered are heritage-protected.
- The mounds at Bingie Bingie Point, now covered by grass and other plants, are extensive middens: granite fissures were home to plentiful shellfish making this an ideal place for the feasting of the Ancestors.
- Everywhere are dikes, far more substantial than the ones we stumbled across on our first exploration.
- Here we are standing on Gondwanan rocks, where the earth folded under pressure.
- Here, a great chamber of magma created two different and incompatible granites. One lot of magma split, moved around an incompatible bit, and islanded it in an inconceivably-long-ago-then till now. The granite we are standing on extends down to the mantle.
Close by a whale surfaces and a pod of dolphins arch through the water. They are intruders, time travellers, drawing me back unwillingly into the future, away from long-ago earth processes that still continue today.
I'm off again till the end of November, on a camping volcano crawl through western Victoria. So there'll be silence till my return.