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General Climbing Discussion

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6 areas in 6 weeks 30-Oct-2007 At 2:52:22 PM wombly

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>is that a silica glued rock is much like nowra and a iron glued rock is like the county

Nowra definitely has a nice solid silica cement. It's been a while since I was out at the county but you could be right. The grey wall (with the easier grade climbs) at boronia point is an excellent example of an iron cement.

The geological maps are great if you want to know the how and when the rock was first deposited (i.e. is it a sandstone, basalt flow, granite intrusion etc) and how it has been faulted or deformed since. These tend to be pretty easy to map over large areas, and are what people generally find useful for predicting mineral deposits (e.g. coal), soil types etc. Unfortunately what happens afterwards is often less economically imporant, and much harder to predict, so that sort of info generally isn't collected, although it must be important for the geotechnical engineers that build cuttings and foundations, so i imagine that they might have a better idea on where to find it if it does exist.

FYI, my knowledge comes from a combination of a farily extensive literature review for some landscape evolution research i'm doing in the Nattai combined with 5 years of climbing/walking/canyoning around sydney.