What are these rocks doing here? Why not take a closer look to find out.
These rocks are but a tiny example of the amazing things to be found in the rocks of this area. What is so amazing about them? Fossils. Not just any fossils, but Ordovician and Silurian sea fossils.
SEA?! Here???
Yes, here you have evidence that Molong was once below sea level.
I find it fascinating that fossils like these can be found all over the area. I first realised there were fossils here when I was admiring the rocks in a friends paddock and nearly stepped on a bunch of brachiopod fossils. My eyes suddenly adjusted to see that there were a large variety of fossils all over the rocks in this paddock. Driving home I noticed these rocks in a public location, and upon further inspection, found them to be the same. Years later I'm finally creating the Earthcache to share these fossils with you.
About fossils. As a child I thought fossils were the outline of a plant or creature (organism) that had died and that organism just turned to dust. Wrong. Fossils are the actual organism turned to stone. Simply put, over a long period of time the minerals in the soil surrounding the organism and soil soak (leach) into them, causing them both to eventually turn to stone. Because the organism was composed of different things than the soil that surrounded it, when it all turns to rock it can look a little different. The rock can sometimes break apart easily where the soil and fossilised organism meet. Older fossils like the ones here have become visible due to erosion of the surrounding soil part. The organism became a more solid rock than the soil.
So, how old are these fossils? These organisms were known to exist in the Ordovician and Silurian periods. The geology of the area varies with the Mid Ordivician to Wenlock Epochs being represented and found on the surface. Therefore we are looking at somewhere between 460 and 430 million years ago. That's pretty old! Touching these rocks I like to imagine it's kind of time travelling and being in both times at once. haha
What are these fossils of? This is where it gets fun. To qualify for a smilie on this Earthcache you will need to find or guess this yourself. I have added a number of pictures to the gallery to help you with this.
You must:
1. Choose any fossil in this group of rocks.
2. Take a photo of the chosen fossil to be sent with the answers (but not added to the log).
3. From the pictures I have supplied in the gallery try to identify the fossil. It does not need to be exact. Using my nearby sea shell find as an example, "Brachiopod" is sufficient, rather than "Brachiopoda Rhynchonellata Orthida Plectorthidae".
4. What are your thoughts on how this area came to be over 500 meters above sea level and so far inland? Scientific or creative answers are both welcome.
Go ahead and log as found but without any close up photos of the fossils. Photos of the general area, or other fossil finds in the area are acceptable. Please send me the answers and photo within 2 weeks of logging your find. If you know anything more about the geology or fossils, please feel free to add this to your message or log. I'd love to learn more.
Thanks.
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If you are interested, here are some links to further reading on the local geology, Australian fossils, and the Ordovician period.
Interactive map of local fossil finds
Another interactive map of local fossil finds and more
Map of local geology
Australian Fossils, 1914 - a lot more has been discovered since, but this is an easy guide for beginners
The Ordovician Palaeogeography of Australia, 1990
- NOTE: Ordovician, Devonian, Silurian... all these can be found in the Central West NSW. Just because one is found 'just down the road' doesn't mean the entire area is that age.