Porosity evolution and fluid flow in the basalts of the Skaergaard magma-hydrothermal system, east Greenland

Abstract

Deformation and heat transfer associated with the Skaergaard intrusion caused a meteoric hydrothermal system in the fractured gabbros and their basaltic host rocks. In the basalts, fluid migration accompanied contact metamorphism and occurred in a network of macroscopic structures which included primary pores, hydrothermal breccias, and fractures. The evolution of porosity and fluid flow during contact metamorphism in the Skaergaard magma-hydrothermal system reflects systematic interrelationships among a changing state of stress, magma emplacement and crystallization, heat transfer and associated changes in fluid pressure, and mineral precipitation in the pores. -from Authors