In the history of geology theirs is an extremely important role: due to the detailed study of these volcanoes have been resolved a bitter dispute about the origin of basalts. Central plateau of France rises about 1000 meters above sea level and consists of ancient crystalline rocks, mainly granite. In some places there are here and freshwater Tertiary sediments, rises above them the latest igneous rocks, which by their location, and partly by age fall into two distinct groups. On the one hand, we find here large volcanic centers that occupy significant space and form a whole system of mountains are ancient volcanoes of the Tertiary period: the influence of the erosion of the crater collapsed, and yet gone any outward signs of their volcanic origin. On the other hand, we found a huge number of small volcanoes. Page 1 of 2 | Next page
No comments:
Post a Comment