Logging our first Earthcache

I'm a real fan of Earthcaches. So how better to start hiding caches than with an Earthcache.

They're a great way to find out about the geology of the earth, especially the geology either local to you or the places that you visit, for instance, on holiday. With an Earthcache, you don't find a container, you find a place. The Earthcache site has a write up on the Geocaching website, explaining the processes that led to the creation of the place. It will also give you a task. Sometimes the task is measuring a block of rock and working out how much it weighs! Ours is a bit easier than that, we just want people to visit a massive chalk quarry and estimate how long it took for a section of the chalk to form.

The location of this Earthcache is also the location of the Westbury White Horse and from the top of the hill there are wonderful panoramic views of the rolling Wiltshire counryside. It's also on of the possible locations for the beginning of England itself when King Alfred defeated the Viking Army in 878AD. So you can see that this is a special place for an Earthcache.

Here's the write up that I've written for the listing:

"This cache takes you to the boundary of a large chalk quarry, called Beggars Knoll. This quarry has been used since 1962 by the cement factory down the hill, where after excavation, the chalk was crushed and mixed with water before being piped down to the factory.

There is plenty of parking, either at the white horse or closer to the quarry itself. The parking waypoint is the closest you can park for this cache. There is a compacted path to walk along, the quarry is to the left.

What has brought us to this spot is the massive scar on the landscape. But while it may be seen as a blot on the landscape, it offers us a unique opportunity to look back for millions of years. At least 65 millions years, to be more exact. This chalk was formed in the Cretaceous period, the last period of the dinosaurs, and the majority of the chalk is part of the Zig Zag Chalk Member.

A this time most of Wiltshire was under a few hundred metres of warm sea. Many sea creatures lived on the sea bed here and local geologists have found fossils of sea urchins and crabs, as well as minute shells of alga.

The depth of the quarry is 80 metres and it's said that there is a further 60 metres of chalk below that. The chalk will have built up over a long period of time, perhaps up to 30 million years. It is said that the chalk reportedly accumulates at a rate of around .5–3 inches (1.25–7.5 cm) per thousand years.

When you reach the cache location it is possible to see, faintly, layers of flint in the chalk. This is thought to be from the remains of organisms that used silica to build their skeletons, such as sponges. In pre-historic times, humans used filnt to make weapons and tools.

From the cache location, look for the track in the quarry, follow this to the far side and estimate the distance from the track to the top of the quarry, if the chalk had accumulated at 7.5cm per thousand years; work out how long it would have taken for this amount of chalk to build up. To claim this cache as a find, please email us with your estimate of how many years it would have taken for the chalk in this section to build up.

While it's not neccessary to claim this cache, it would be nice to see photos of you or your GPS with either the quarry or the chimney stack of the cement factory in the background."

Many thanks to our reviewer geoawareUK2 who helped us iron out some details and proof read my test!

Want to go find it? It's GC3J11Y and called Westbury Zig Zag. I can't show you a photo of the quarry, as that would give the game away. But here's a photo of the view if you turn the other way - wonderful Wiltshire countryside - cement factory chimney stack and all!

Interested in learning more about Earthcaches? See this video about Earthcaching from Geocaching.com: