NOTE:
This is an EARTHCACHE!
There is NO PHYSICAL CONTAINER, and to log a find you need to email the answers to the questions below to me, by clicking on 'heartradio' just below the cache title and then clicking 'Send Email'.
If after 24 hours of you logging your find I haven't received any answers, your log may be at risk of being deleted. Sadly.
RIPPON TOR
A CRYSTAL CLEAR VIEW!
Rippon Tor is one of my favourite spots on Dartmoor, as you can see for miles all around on a clear day. This should be a straightforward Earthcache to complete while admiring the aforementioned views and taking a break after a fairly steep climb up. The tor has for centuries been a landmark used by sailors when coming into the harbour of Teignmouth and Dartmouth.
Placed in accordance with the DNPA Geocaching Guidelines.
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LOGGING TASKS
To log this cache, please email the answers to the questions below to me through my profile. You can do this by clicking on 'heartradio' under the title and then clicking 'Send Email'. DO NOT POST THE ANSWERS IN YOUR LOG!
1) Look around at the landscape. Give an example of weathering and erosion and state either the location of it or a compass bearing for it.
2) Beside the trigpoint there are granite rocks and boulders forming a cairn and many crystal veins can be seen in these rocks. Describe the appearance of the veins.
3) How do you think they were formed? State whether you think the magma cooled slowly or quickly. How do you know?
4) Estimate or measure your altitude at GZ.
OPTIONAL: Take a photo of your GPS on top of the trig. DO NOT POST PICTURES OF THE CRYSTAL VEINS OR ANY CLOSE UPS OF EROSION AND WEATHERING.
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GEOLOGY
Tors, Weathering and Erosion on Dartmoor
Tors and clitter slopes, examples of which can be found in the area surrounding Rippon Tor, have been formed through the weathering of the granite over at least the last ten million years. They are concentrated where the effects of weathering and erosion have been greatest, ie on summits, valley lips, spur ends and steep valley sides, particularly on the edges of the two great plateaux of Dartmoor and close to the main river gorges. Tors are the remnants of former landscape surfaces. Weaknesses and joints in these surfaces have been subsequently exploited by acidic waters over a long period and by freeze-thaw action during the four Ice Ages. Blocks of granite are levered away by these processes leaving the tor isolated and exposed and littering the ground below with boulders, thus forming the clitter slopes. Weathering eventually causes the disintegration of the granite down to individual crystal level. The resultant gravel is called growan. During periglacial times it became very mobile - moving down slopes and accumulating on flat ground as head deposits. It is the parent material for a number of Dartmoor soil types.
Information from http://www.dartmoor.gov.uk/
Formation of Crystals in Granite
The inside of the Earth is very hot - hot enough to melt rocks. Molten rock forms when rocks melt. The molten rock is called magma. When the magma cools and solidifies, a type of rock called igneous rock forms. Granite is an igneous rock. Igneous rocks contain randomly arranged interlocking crystals. The size of the crystals depends on how quickly the molten magma solidified. The more slowly the magma cools, the bigger the crystals. If the magma cools slowly, large crystals form in the rock. This can happen if the magma cools deep underground. Granite is an example of this type of rock. It is an intrusive igneous rock because it forms from magma underground. Unlike sedimentary rocks, igneous rocks do not contain any fossils. This is because any fossils in the original rock will have melted when the magma formed.
Information from http://www.bbc.co.uk/bitesize/
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