Sands of time …

A compromise title, I figured that the more obvious Geology of the Kimberley would get little attention in the blogosphere whilst Kimberley Gets Her Rocks Off might get the wrong sort.

The Kimberley that you see as you cruise past is what’s left by processes over eons. The time involved is almost unimaginable compared with a human lifespan and the processes seem extraordinary but they could not be more ordinary. It’s all a matter of some key events, time in abundance and weather.

The first key event happened two billion years ago when a little tectonic plate, the Kimberley Craton, smacked slowly into the North Australian Craton. The Kimberley Craton rode up over the other forming a mountain range that probably rivalled the modern European Alps in size. (Kimberley likes it on top).

Erosion commenced and the products were washed into the adjacent shallow seas forming sandstone which is up to 5km thick in places. Uplifting and the outpouring of basalt (especially in the Mitchell Plateau and Ord River region) followed by more erosion. Add a few volcanic injections of dolerite (especially the King Leopold Range). Take a great barrier reef and raise it well above modern sea-level as the Napier and Ningbing Ranges and all you need to do now is to add flora and fauna.

To summarise, on this cruise you will be seeing a lot of sandstone.

In the southern section it will be very impressive because it is folded. Further north it will be very impressive because it is not. It will be most impressive early and late in the day when the low sun falls on it.

Folding
Folding
Tilting
Tilting
Block faulting
Block faulting

And where conditions are right the uppermost blocks can undergo further weathering to produce beehive like structures. This can be seen on a grand scale in the Bungle Bungles but also occurs on the coast …

If you are inclined to study this topic more thoroughly here are a couple of handy links …

kimberleycoast.com.au/kimberley-geology/

sciencewa.net-kimberley-alps

Or just continue the cruise …

 

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