Addingham Edge is an escarpment that sits at the western end of the Ilkley Moor massif. It has been quarried in the past, though not recently. This EarthCache takes you to a feature associated with the local geology. It is rough underfoot, with very uneven ground, so be careful, and watch your footing.
The Background.
Up on Addingham Edge, you get a great view up Wharfedale, with the village of Addingham in the foreground, then the hills of Beamsley Beacon, Round Hill, Great Whernside, Buckden Pike taking up the vista. The predominatary feature is the Wharfe Valley, through which the river flows.
Lets now step back in time to an era known as the Upper Carboniferous, during which the foundations for the local geology was laid down. At this time, this part of Yorkshire and neighbouring Lancashire was covered by a vast river delta, similar to the Amazon basin of today. The rivers feeding this basin originated in high mountains far away. As these mountains eroded, a vast amount of sediment was carried down stream, and then depositied in layers, which is called strata. The sediment consisted of sand grains, small rocks of feldspar and quartz. Over time the starta build up, and over millions of year a rock known as sandstone was formed. The rocks in the area that you are standing in at present, are a type of coarse grained sandstone, known as Addingham Edge grit. This rock was laid down in the Upper Carboniferous period (also known as the KinderScoutian) about 320 million years ago.
There are however different types of sandstone, laid down at different times, and should you visit the nearby Doubler Stones EarthCache (https://www.geocaching.com/geocache/GC76RAX_doubler-stones-ec) you will find a younger sandstone.
So why have I brought you here?
There are plenty of EarthCaches that talk about sandstone, but not many that talk about a direct association with it. Addingham Edge Grit, can be classed as gritstone, and another name is millstone grit. Millstones, were used in the past to grind flour and other items. Here we have a millstone, which has been started to be formed by the quarrymen in years goneby.
This being an EarthCache, in order to log it, I ask that you complete some tasks. Please send the answers to me, and do not include them in your log. You can send them to me by using the message facility or email, both of which can be found by looking at my profile.
Lets look at the millstone:
(1) Please look at it, what feature does it have on its planar aspect?
(2) Get down to the millstone, is it complete, or still in the process of being formed?
(3) Close your eyes and run your hands over the millstone, what does it feel like, is it smooth, rough, have an even feel or uneven feel?
(4) Open your eyes, and now look closely at the millstone, get right up to it, described what you can see. PLEASE DO NOT SAY A ROCK!
(5) Measuring the millstone, how deep is it?
(6) Measuring the millstone how wide is it?