Globulith, a new type of intrusive structure, exemplified by metabasic bodies in the Moss area, S.E. Norway.

Abstract

Intrusion of basic magma into a regionally preheated gneiss complex has given rise to oddly shaped, globular to botryoidal, intrusions with associated contact anatexis and contact deformation whereby pseudoconcordant contacts developed on a local scale. The term globulith is introduced for this unusual type of intrusive structure. It is suggested that osmotic pressure contributed to the special intrusive mechanism of the globuliths. The structures of certain hyperites are compared with those of the Moss globuliths, and the analogy between globuliths and near-surface associations of basic and acid magmas are discussed.