Saturday, April 04, 2009

There And Back Again, Chapter Eight. Wonambi Fossil Centre

The Wonambi Fossil Centre down at the Naracoorte Caves World Heritage Site is quite the place. Firstly, it's nestled into the middle of the scrub landscape so you hardly even know it's there.

We actually started here at the Centre, but didn't go into the exhibits till after the Alexandra Cave Tour. Hence, you got to see some cool cave pics first, and now you'll get to see the Wonambi Fossil Centre.

BTW, the rainbow serpent of the aboriginal dreamtime is called Wonambi. Since there were many fossils of giant pythons (similar to the recently discovered South American ones) you can probably guess how the Wonambi Fossil Centre got it's name. For those of you not familiar with The Dreamtime, I'd suggest you open google and let your fingers do the walking.

The Naracoorte Caves are unique among fossil sites worldwide in that it's the only place where there's an unbroken fossil record from 500,000 years ago to "recent". Well, how did that happen?

The limestone was laid down by not only shellfish and their ilk, but also by microscopic sea critters during a 20,000,000 year span starting about 25,000,000 years ago. That means that by 5 million years ago, the Naracoorte ridges were "high and dry".

How do fossils from 100,000 years ago get into rock that solidified a long time before they were born? Ahhhh, this is where limestone geography and ground water explain things. Basically, the whole underground region is a porous and very permeable aquifer. Rain that fell on the "mountains" over the border in Victoria is dripping through the caves as you read this. The water did take a "while" to get there... 200,000 years or so --which explains why the bore water in Naracoorte DOES NOT TASTE GOOD.

Anyways, the water dissolves the limestone. Caves form, and there's all sorts of little interconnecting tunnels or tubes (called squeezes) that connect really big chambers.

And these interconnected chambers (shall we call them caves?) have NO contact with the surface. Yes, I know you're all thinking sinkholes, but that's not what happened. Solution tubes would form from the surface where rainwater had accumulated. So there would be (and still is in some caves) a "hole" down to the caves. Think of it sorta like a manhole in a street without the cover on. Now cover all of the street with dirt, greenery, trees, etc. Would you even be able to see the hole?

Hmmmmm, neither could the critters that fell the hole. No Lewis Carroll jokes, thankyouverymuch.

Soil and detritus (fancy term for DIRT) also falls down the hole. Critter that falls down the hole have a long drop. It adds it's carcass to the ever growing pile of dirt in the cave chamber at the bottom of the solution tube.

There are so far about 100 of these type of sites identified in the known caves, of which only 4 have been excavated. Hmmmmm, any paleontologist want a job for the rest of his or her life? Job security!

Anyways, that's how the fossils from extinct (and some not extinct) critters got down into the caves.

Getting back to the Wonambi Fossil Centre.

Not only are there some really cool fossils there, but they've re-created what the area looked like a few hundred thousand years ago. You enter and you are in a very lush jungle with critters everywhere. But these aren't static models. They are animatronic. And they have motion sensors so when you walk past one it turns it's head, opens it's jaws and growls.


You then go underground into a cave system mock-up. All sorts of things are going on down there! At one little nook in the caves as you look at the fossil skull of some little critter you'll hear a noise above you... A big ole Wonambi naracoortensis is nestled in a crack 2 feet above your head!

I thought that was very cool. However, there was one lady walking through there who didn't like at all. In fact, her words were, "They shouldn't be allowed to do that!" And she was serious!

There were also goodies hidden in the nooks and crannies that most people would miss. Fortunately for you, I'm not most people :)

Here's the flickr slideshow of pics from both YT (Yours-Truly, that's me) and WP (Wifey-Poo, or The Most Wonderful Woman In The Entire World).

As usual, you can view it fullscreen just by clicking on the little box on the lower right hand side of the slideshow, no worries.

Oh, and here's a link to a thumbnail page of the entire set, no worries.

Do I need to tell you I thought the set with the wallaby in the snake's coils was neat?

If you want to learn much more about the area, just check out this site called The Story Of The Naracoorte Caves!


trevs72 said...

what a fantastic park and center.
thanks for the education, Dave.
I'll have to put it on the list next time I'm in SA.

Alaskan Dave Down Under said...

trevs72: No worries mate. It really is a cool place. Next time we are down that way we'll be doing all the caves and such in Mt. Gambier area. If you're driving in from Vic, Naracoorte and the area is the first place you'll hit. If you fly into Adelaide it's only a 3.5 hour drive (we took six cus we dawdled)