In the Kongsberg-Bamble series of south Norway leucocratic albitites are associated with amphibolites. The plagioclase of the albitites is An 2 -An 13 , that of the amphibolites is commonly An 28 -An 40 . The metamorphic facies is upper almandine amphibolite and the inferred P.T. conditions are about 700 degrees C. and 7,000 to 8,000 bars. Recent experimental work indicates that at these temperatures and pressures amphibolites will begin to melt and the first liquid will be of albitic composition. It is suggested that the albitites owe their origin to the partial fusion of their enclosing amphibolites.

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