While their magmatic origin is clear, there is little agreement as to the precise conditions which determined their segregation in the molten rock.
"The Economic Aspect of Geology"
C. K. Leith
While the evidence is sound that the magmatic process has been an important one, it is difficult to see how and to just what extent this process may have been related to the action of ground-waters,-which were probably present in a heated condition near the contact.
"The Economic Aspect of Geology"
C. K. Leith
A magmatic origin of the tungsten is probable.
"The Economic Aspect of Geology"
C. K. Leith