The Formation of Worsendale
It is important to know chalk is a very permeable rock so is very good at holding water. A rock which holds water is known as an acquifer.
Water now flows underground and emerges where the permeable rock i.e. chalk meets an impermeable rock i.e. clay, this formation is known as a spring. The map below shows this on a section of the Wolds, the springs are indicated by ‘Sprs’ in the purple boxes.
Here, springs are located where the escarpment (chalk) and the vale (clay) meet.
Now we move on to the formation of dry valleys, dry valleys around here were formed at the end of the last ice age, fast moving water from melted ice carved out dips in the scarp slopes. As chalk is very permeable this water was easily drained away allowing the newly formed streams to simply run dry and start running underground through an acquifer rather than on the surface. This is evident as no streams run through Worsendale, the stream only starts where the chalk meets the clay.
How to Claim a Find
To claim this Earthcache please answer the question below and send the answer to us via the 'Geocaching Message Centre' (there's a link to the message centre at the top of this cache page under 'Message This Owner') or via e-mail.
Walk to GZ along the side of the road from the recommended parking area, find a small walnut sized sample of chalk, take this home and follow the steps below
- Note down its mass.
- Submerge the sample in water and leave it for 12hrs.
- Once the time is up, note down the new mass and send us your observations.
A picture of you and/or your GPS overlooking the dale is also appreciated.
Good Luck!