The pink granite you see today is formed it 300 million years ago during the Paleozoic era to the rise of the Hercynian chain. Indeed, at the time the coast of pink granite was not much on , but was buried under a mountain range . As you can see in the diagram below, the magma ascended and formed a magma chamber located 5 km deep . After the almost complete erosion of the Hercynian chain, it is the turn of pink granite from being eroded by the wind, frost and runoff , which formed the great odds that we now know.

Accurate mapping of Ploumanac'h complex, delivered in 1976 by Michel Barrier , shows a remarkable arrangement of the different lithological units in concentric rings. Consisting of successive magmatic intrusion of three bodies they realize what is called a " complex centered " , like those that exist in some regions.

The halo outermost , in contact with older rocks is occupied by the famous pink granite whose most classic facies , bright red, to plurimillimétrique grain qualified type Clarity . The pink color of the granite is largely due to the presence of iron oxide ( hematite ) in the crystal lattice of alkali feldspar . The quality of granite is its weather resistance and therefore the time. This is due to its composition : crystals harder than steel quartz , feldspar crystals also very hard and some mica . All these crystals are assembled to form a rock at the sight ' grain ' , in Latin " granum " hence the name of granite . (Source: website of the Geological and Mineralogical Society of Britain)

This is a EarthCache no box , but a few questions.

Question 1: What is the diameter of the hole of the pallet centimeter painter ?

 Question 2: A special feature lies in the gray area , what are the dimensions for the length A-B and C- D width in centimeters ? (view the photo)

 Question 3: In your opinion, how is formed the hole ?