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The Rescue EarthCache

Hidden : 7/28/2024
Difficulty:
1.5 out of 5
Terrain:
1 out of 5

Size: Size:   other (other)

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Geocache Description:


This statue on Castle Street commemorates firefighters who have died in the line of duty. 

The base also has an interesting feature than can sometimes be see in granite and gives a little clue as to how it was formed. Have a look and answer the questions below.

1) Look at the side of the statue with the plaque that says "Roll of Honour" and describe the feature you can see
2) Of the Aptite Veins, Xenoliths and Phenocrysts (see the description below for information on how to recognise them) which features is this?
3) How was this feature formed? 
4) Take a photo of yourself at GZ, or an identifying item, being careful not to reveal any of the answers to the questions. 

Please submit your answers via message though the Geocaching website or via email - there is no need to wait for a response before logging your find.

Granite Features

Aptite Veins

Aptite veins are thin, sheet-like bodies that cut across host granite. They consist of fine-grained, light-colored minerals like quartz, feldspar, and mica. These veins form when late-stage, silica-rich magma intrudes into fractures in the granite and cools rapidly.

Phenocrysts

Phenocrysts in granite are large, visible crystals within a finer-grained groundmass. They form when minerals like feldspar, quartz, or mica crystallize early during the cooling of granite magma. These early crystals grow larger than the surrounding minerals.

Xenoliths

Xenoliths, are foreign rock inclusions found within igneous rock formations, such as granite. Their formation begins deep within the Earth's crust, where molten magma slowly cools and solidifies to form granite. During this process, pockets of magma may intrude into existing rock formations, incorporating fragments of the surrounding rock into the cooling magma. These fragments, known as xenoliths, are often of different composition and texture compared to the surrounding granite. As the magma cools and crystallises over time, the xenoliths become trapped within the granite, preserving a snapshot of the geological history of the area. 

Xenoliths are usually visible. They have a different color and density than the surrounding igneous rock. Xenoliths can be as small as a grain of sand or as large as a football, and as long as several meters. 

Additional Hints (Decrypt)

Guvf vf na rnegupnpur, gurer vf ab culfvpny pbagnvare gb svaq. Lbh jvyy svaq vasbezngvba va gur qrfpevcgvba gb uryc lbh nafjre gur dhrfgvbaf.

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)