Giant's Footprint EarthCache
Hidden : 1/10/2024
Difficulty:
2 out of 5
Terrain:
2 out of 5

Size: Size: other (other)

Join now to view geocache location details. It's free!

Watch

How Geocaching Works
Looking for a different adventure?

Please note Use of geocaching.com services is subject to the terms and conditions in our disclaimer.

Geocache Description:


Another EarthCache to add to the growing number in Bristol. The majority of them are in and around the city centre, so here's one a bit further out, in the Blaise Castle Estate.

This EarthCache highlights the Giant's Footprint rock formation and explains its creation.

Questions
 Questions first, as the cache page is quite long and has many images, which some GPS devices may not be able to load fully. To log this EarthCache, please send the answers to the following questions by email or message. Due to owning many EarthCaches I receive numerous emails per day so there is often a delay in replying, therefore feel free to log before awaiting a reply. Only answers that are drastically incorrect or photos that reveal answers will be deleted.

 1. Estimate (or measure) the size of one of the clints that make up the Giant's Footprint. Why do you think the sizes vary?

2. Have a feel of the clints of the limestone pavement- Is the surface rough or smooth? Why do you think this is?

3. Why do you think the grykes here might be less prominent than in other limestone pavements?

4. (Optional): Include a photo of yourself/GPS at the footprint or a photo of something nearby. Please don’t post photos that reveal answers; any that do risk being deleted!

Legend has it that various antics of two brother giants, Goram and Vincent, are the cause of many landmarks and formations in the Bristol area.

Unfortunately for them, they were both in love with the same woman, Avona (the namesake of Avon). Unable to decide between the two giants, she set them both a challenge: she would marry the one who could carve a river to drain a giant lake which devoured a large area between Bristol and Bradford-on-Avon.

Goram, the lazier of the two, rested a short while into the task, got drunk and slept on his armchair (another rock formation in Blaise)- his measly efforts are supposedly the trickling Hazel Brook river tributary we see in Henbury today. Vincent, however, paced himself much better, and carved out the spectacular Avon Gorge, successfully draining the lake into the Bristol Channel. When Goram awoke to find he had failed in the challenge and therefore didn't win Avona, he stamped his foot into the ground in anger- creating the Giant's Footprint you see here. Then, he drowned himself in the Severn- the islands of Steep Holm and Flat Holm supposedly being his submerged head and shoulders.

The Earth Science
However intriguing the mythical story, it is only a legend, and geoscience can produce a much more realistic explanation to this formation.

A limestone pavement is a distinctive geological feature characterized by a flat, exposed surface of limestone that has been weathered into a pattern of deep fissures (called grykes) and blocks (called clints). These landscapes are often found in karst regions where limestone is the dominant rock type- such as The Blaise area of Bristol, which sits on a bedrock of limestone. Blaise has ideal conditions for a limestone pavement to form: significant limestone bedrock, a fairly flat area (such as this gulley) and a thin soil layer - which is the case here.
As tough as limestone can be, it is no match against glaciation, which has carved out these striking cliffs and vastly uneven terrain that makes the Blaise estate a challenging walk in some areas!

The Giant's Footprint is a smaller example of a limestone pavement, which can sometimes extend across a much larger area. It is formed through the following processes:

Glacial Action:
During the last Ice Age, glaciers moved across the landscape, stripping away soil and rocks that once covered the limestone bedrock. The considerable pressure and movement of the ice eroded the exposed limestone, leaving a relatively flat surface.

Weathering:
Over time, rainwater (slightly acidic due to absorbed carbon dioxide) seeped into vertical cracks in the limestone, dissolving the rock through a process called carbonation. This widened the cracks, creating the distinctive grykes.

Erosion:
Continued water drainage through these fissures further shaped the surface, deepening the grykes and leaving the clints in between.

Additional Hints (Decrypt)

Ba gur tebhaq orarngu lbh.

Decryption Key

A|B|C|D|E|F|G|H|I|J|K|L|M
-------------------------
N|O|P|Q|R|S|T|U|V|W|X|Y|Z

(letter above equals below, and vice versa)


Advertising with Us