Dinosaur Digging – Australian Style (Part 2)

Wearing a wide-brimmed hat, slathered in sun screen and carrying plenty of water, we head off to the dig site, which is about 2 km from the shearing shed.  It’s along a narrow track that includes passing through a gate where you have to get out of the car to open and then close the gate after you pass through it so that sheep and cattle stay in the right paddock.  We finally come to a spot that doesn’t look any different from the other thousands of acres of land you can see in all directions.  The two bona fide paleontologist of the group clearly see more. 

Even a closer look by us amateurs reveals an abundance of fossils littered across a 30 meter by 30 meter area.

And the first real find of the day occurs – the fossilized footprint of a small three-toed theropod dinosaur.

But first we need to put up the tent that will protect us from the Sun – although it does nothing to stop the heat from coming up from the ground – or stop the incessant wind, dust and flies.

The next task is for us to line up and walk slowly across the 30 meters and mark each large fossil fragment with pink ribbons  on the end of metal stakes.

The visual sea of stakes does a nice job of identifying the area for further work and where the front loader will ultimately clear away the top two meters of top soil.

Digging dinosaurs in Australia is different than in the US because of this top soil – called Black Soil by the local ranchers.  Not sure why it is called Black Soil when it is really brown – but it is darker than the underlying light sandstone two meters down.  In the US you typically see dinosaur bones eroding out of the sides of gullies being worn away by water and wind.  There are no gullies in this part of Queensland.  But they talk about the soil being “self mulching”, which is why the bones are found littered on top of the ground.  The Black Soil gets slick and sticking when it rains, but big cracks form when the ground dries.

The next time it rains, the water drains into the cracks and carries the soil at the top back down towards the bottom.  One can think of this as a very slow convection current that brings material from two meters down up to the top and then back down again.  Any dinosaur fossils at the bottom of the two meters slowly float to the top, but they are too big to return to the bottom  in the convection process.  Over thousands of years, the fossils collect at the top of the ground – waiting for us to walk along and collect them.  Of course, the big prizes are the major skeleton fossils that hopefully exist two meters down.

The area defined by the location of the flags becomes the dig site and is divided into sections in order to keep track of where each fossil comes from.  But before we get serious about collecting the fossils, it is Smoko time – which means time for a smoke and cuppa tea.  But no one smokes and few drink tea. 

Once Smoko is over we start collecting the fossils from the surface and put them in large trays for cleaning.  Plain old rocks are carted off to a separate area where people with more fossil identifying skills than us volunteers will search through them to make sure we didn’t miss anything important.

 

This is as far as we get on the first day.  Digging down to the sandstone layer will have to wait until another day.  Now it is time to got back to our home-away-from-home and enjoy a shower (women first and then the men) and enjoy a few beers while watching the sunset.

Advertisements
This entry was posted in Uncategorized. Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

w

Connecting to %s