The Skaergaard Intrusion of East Greenland: Paradigms, Problems and New Perspectives

The Skaergaard Intrusion of East Greenland is the quintessential example of low-pressure closed-system fractionation of basaltic magma. Field evidence of extensive layering and associated quasi-sedimentary structures, and the resultant ‘cumulate’ paradigm of crystal settling in magma chambers, has led to many long-standing controversies. Of particular significance is the lack of consensus about the microstructural record and the mechanisms by which interstitial liquid is expelled from solidifying crystal mushy zones. Skaergaard remains a cradle for new insights into igneous processes, with recent work highlighting the importance of separation of immiscible liquids on magma evolution.