Welcome to Ilkley Moor! This cache is one of a series of caches that will take you on a tour of some of the many geological features that you can find at this scenic location.
Ilkley Moor
Ilkley Moor is an area of upland moorland, covering 676 hectares. Internationally, this type of moorland is rare, despite being relatively common in the North of England, and as a result has significant nature conservation interest. Mosaics of heather moorland, blanket bog, acid grassland and flowing streams make up the character of Ilkley Moor. Mixed with these are small stands of pine woodland, scattered trees, tarns and exposed rock faces.
Ilkley Moor is underlain by a succession of shale and course grained sandstones including the Addingham Edge Grit that forms the Cow and Calf rocks. The sand that forms these rocks was originally laid down on shifting sandbanks in a great river about 320 million years ago during the Carboniferous Period.
Deep burial caused the sand to harden into rock and subsequent earth movements and erosion brought the rock back to the surface again. By the end of the Ice Age, about 13,000 years ago, ice had scoured the moor and deposited the long low ridge of Lanshaw Delves, a glacial moraine. Since then peat has accumulated in sphagnum bogs.
Peat
Peat is an accumulation of partially decayed vegetation or organic matter that is unique to natural areas called peatlands. In natural peatlands it takes thousands of years to develop the deposits of 1.5 to 2.3 m which are the average depth of the peatlands of the northern hemisphere. Assuming peat will continue to accumulate through further deposits of partially decayed vegetation, buried peat will turn into lignite coal over millions of years, through increased pressure causing temperature rises and therefore chemical reactions on the material.
Sphagnum moss, also called peat moss, is one of the most common components in peat, although many other plants can contribute. Peat forms in wetland conditions, where flooding obstructs the flow of oxygen from the atmosphere, slowing the rate of decomposition. Peat material is either fibric, hemic, or sapric. Fibric peats are the least decomposed and consist of intact fibre. Hemic peats are partially decomposed and sapric are the most decomposed.
Under pressure, water is forced out of peat, which is soft and easily compressed, and once dry can be used as fuel. In many countries, including Ireland and Scotland, peat has traditionally been used for cooking and domestic heating, and peat is stacked to dry in rural areas. Wet or dry, it can be a major fire hazard. Peat fires may burn for great lengths of time, or smoulder underground and reignite after winter if an oxygen source is present.
Logging your Find
In order to log your find, please send a message to my profile answering the below questions. The answers can be found by visiting the location, reading the above description, and taking observations in the field.
Look at the sphagnum moss below your feet.
- Describe how the moss looks, and reacts when you touch it or apply pressure to it, and how that gives evidence of a peat bog.
- Explain whether you think that the peat here is fibric, hemic, or sapric, and why.
As Ilkley Moor is a stunning part of the world, you may optionally want to upload photos of your visit, of course I would love to see them! You can log your find immediately, but please send the answers within 24 hours. I will respond to your message as soon as I can. Logs where incomplete answers have been given, or where an email has not been received, may be deleted.