I’m a freelance proofreader and line editor. My job often involves looking at texts produced in fields of work that I’m unfamiliar with. I prepare myself for that by learning about new subjects in my spare time.

Recently, I’ve been exploring geology. To start with, I had no idea what to expect. I didn’t know what geologists did beyond identifying rocks. The resources I’ve read and watched since then have shown me that geology is actually quite exciting!

Rocks and minerals are a record of events that happened millions of years ago. We live surrounded by ancient history. This was brought home to me by a recorded lecture I watched through my membership of the Geologists’ Association.

It was called “Are ‘shales’ really that dull? Continuing to shine light into dark places and what happens when you open Pandora’s Box!”

Shales are a type of sedimentary rock. They form in water from layers of clay, mud, silt, and organic matter. Like tree rings and deeply buried layers of ice in Antarctica, they’re a record of nature’s behaviour over a succession of years, long ago.

The lecturer gave the example of a particular cliff and spoke about samples taken from several different levels. The lower samples were millions of years older than the higher ones.

Each sample was thinly sliced and examined under a microscope. It was fascinating because each one looked different, showing what was happening in the water at the time. The lecturer pointed out some short white lines crossing through the layers. These were the burrows of tiny organisms living in the low-oxygen environment of the seabed.

The lecturer also showed a picture of a rock with a beautiful curved line on it. It was evidence of the water current that had deposited the sediment. It was like a photograph of the past.

Many of the details in the lecture went over my head. For example, I had to pause it to look up the meaning of anoxic event. But I appreciated the overall message. I came away understanding that shales are interesting and not at all dull.

I also understood that geologists can work in very fine detail. As a proofreader, I sometimes have to think about the correct placement of tiny punctuation marks. So I can relate to that.