Über den Unterschied der erzbildenden Vorgänge in den Kontinenten und den Ozeanen

Zusammenfassung

Der Unterschied zwischen ozeanischer und kontinentaler Metallogenese besteht vorwiegend in der Tatsache, daß im ozeanischen Bereich die an saure Magmen geknüpften Lagerstätten fehlen. Man erklärt dies zumeist mit der Abwesenheit saurer Magmen in der ozeanischen Kruste.

Abstract

Not only the basaltic rocks but also their acid differenciates in the sphere of the oceanic crust are barren with regard to the forming of ore deposits. The essential difference between oceanic and crustal magmas is the much higher Na₂O/K₂O ratio of the former. If one considers the great quantity of potassium in continental rocks derived from the mantle, this would imply a melting of the mantle to a depth of about 1500 km. There is no evidence for that. An explanation might give the hypothesis of E. V. Artyushkov according to which the differentiation continues at the border core/mantle of the earth until present time.

During this process the light K-rich differentiation products to which the ore-forming elements are bound, ascend. These ascending substances are to be found beneath the continental crust only.

“About the difference of ore-forming processes in continental and oceanic provinces”