Pegmatites are usually thought of as late magmatic emanations from cooling batholithic masses; however, in recent years doubt has been cast on the intrusive nature of many of the larger granitic masses. The granite-gneiss massif used as an example in this discussion is the Kheis granitized geosyncline of South West Africa and the Union of South Africa. From the top downward it is a pile of metavolcanics, gray gneiss and three cyclothemes of metasediments. This complex was previously called the Namaqualand granite-gneiss batholith and thought to be intrusive. If massif is neither intrusive nor batholithic in nature, associated pegmatites cannot originate from its late magmatic products. In addition to the example of the Kheis System, phenomena of the Svionian in Fennoscandia, Hercynian in Corsica and Beltian in Idaho will be mentioned.
Proceedings of the Iowa Academy of Science
©1958 Iowa Academy of Science, Inc.
Enzmann, Robert Duncan
"The Genesis of Pegrnatites,"
Proceedings of the Iowa Academy of Science, 65(1), 299-310.
Available at: https://scholarworks.uni.edu/pias/vol65/iss1/44