The mysterious grinding grooves

Abstract: On the Island of Gotland, there is a phenomenon called grinding grooves, Sw. slipskåror. They occur in bedrock and boulders. About 3600 are known on the island today and having a length of less than half a meter to over one meter. Their purpose was unknown to the scientific community as well as their age. The directions of some 1250 Gotlandic grinding grooves, measured by the author shows there is a correlation to astronomical orientations. An archaeological excavation carried out by the author at a stone with grinding grooves gave some crucial results. The grinding groove phenomenon occurs in some other places in the world as well. In South-West of Sweden, there are quite many in a few places. They are, however shorter and have another appearance because they are more curvature than the Gotlandic ones. Their purpose and age are unknown as well. In France, there are many places with grinding grooves, Fr. polissoirs. Their appearance is more similar to the Gotlandic ones than those in the Swedish mainland. They are supposed to be Neolithic.  In Africa and Australia, there are places with different kinds of carvings in stones. Some resemble those mentioned above, more or less. The difference between grinding grooves and other phenomena is floating.  They are sometimes associated with the circular indentations called cup marks. There are different explanations, and some are supposed to be marks from creating stone tools, while the cult is the explanation to others.