A Sedimentological Fantasy

Today, a special and unique treat for readers, as the LLB Gang's Nature Friday morphs into YAM-aunty's Final Friday Fiction!  

So Thursday morning started as usual with a just after sunrise walk in Duthie Park.

Since it hadn't rained for a couple of days, Gail decided to take me across to the other side of the river, where it was all flooded last week.

I am pleased to report that the water has now drained away, although there was plenty of evidence of the recent inundation.

Here we see some of the vegetation swept downstream by the raging torrent and now caught up in the birch trees and hazels.

Even more interesting was a new patch of sand, deposited by the floods on the riverside footpath.

Can you see the ripples in the sand, formed by the river current? 

Gail pointed out that geological processes can result in such ripples from flood events being preserved in rocks for hundreds of million years (as for example in the Torridonian sandstone by the shore near our west coast cottage). She told me that geologists use features like this to build up a picture of what the landscape was like in past geological eras. From the shape of the ripples the scientists can tell whether they were formed by ocean waves, fast-flowing rivers or even by winds blowing on sand dunes in a desert. Traces left behind by animals can also be preserved and used to further enrich the picture of times past. 

It got me thinking.....

Imagine, a few million years from now, a geologist is chipping away with her hammer, and the rock cleaves open to reveal interesting wavy patterns. Below is a short segment from the paper she subsequently writes:

"The ripples in the coarse grained sandstone are here perfectly preserved and would appear to have been formed in a flood event in NE Scotland during the early Anthropocene. We note that during this period, a marked increase in frequency of storms correlates strongly with a rapid rise in atmospheric carbon dioxide concentrations which in turn led to the subsequent well-known mass extinction which the human species only just survived...

....Other fascinating features can be observed in these sediments from the same location. For example, we note footprints belonging to a human moving in an easterly direction in sturdy walking shoes, alongside the faint outlines of a dog's paw prints. The depth of the paw prints indicates that the dog weighed 7-8 kg, and the highly irregular pattern of the prints suggest that the dog was prone to running to and fro and was perhaps (if we are permitted a degree of speculation here) not the most well-disciplined of animals. That the dog could have been a young wire-haired fox terrier is at least consistent with the weight evidence and the inferred pattern of behaviour...."