Ganralf's EarthCache 10th Birthday Geocoin

TRAVEL AROUND THE WORLD

visited countries / states so far (last update: 12/27/2018) :

and ALAND ISLANDS (without Souvenir)

and KENYA (without Souvenir)

and ETHIOPIA (without Souvenir)

and TANZANIA (without Souvenir)

... hopefully many more to come ...

This travel tag of my "10 Years EarthCache Geocoin" should travel around the world.

The "stone with a hole" attached to this trackable is a unique flintstone from the Shore of the German Baltic Sea.

Chained for you to learn something while bringing this trackable to a new cache ...

Flint is a hard, sedimentary cryptocrystalline form of the mineral quartz, categorized as a variety of chert. It occurs chiefly as nodules and masses in sedimentary rocks, such as chalks and limestones. Inside the nodule, flint is usually dark grey, black, green, white or brown in colour, and often has a glassy or waxy appearance. A thin layer on the outside of the nodules is usually different in colour, typically white and rough in texture. From a petrological point of view, "flint" refers specifically to the form of chert which occurs in chalk or marly limestone. Similarly, "common chert" (sometimes referred to simply as "chert") occurs in limestone.

The exact mode of formation of flint is not yet clear but it is thought that it occurs as a result of chemical changes in compressed sedimentary rock formations, during the process of diagenesis. One hypothesis is that a gelatinous material fills cavities in the sediment, such as holes bored by crustaceans or molluscs and that this becomes silicified. This hypothesis certainly explains the complex shapes of flint nodules that are found. The source of dissolved silica in the porous media could be the spicules of silicious sponges. Certain types of flint, such as that from the south coast of England, contain trapped fossilised marine flora. Pieces of coral and vegetation have been found preserved like amber inside the flint. Thin slices of the stone often reveal this effect.

Puzzling giant flint formations known as paramoudra and flint circles are found around Europe but especially in Norfolk, England on the beaches at Beeston Bump and West Runton.

Flint sometimes occurs in large flint fields in Jurassic or Cretaceous beds, for example in Europe.