Kûngnât Fjeld is an intrusive complex resulting from three intrusive events involving trachyte, mafic trachyte and hawaiite magmas tapped successively from a single magmatic source. In situ differentiation produced gabbroic, syeno-gabbroic, syenitic, and quartz syenitic cumulates showing strong cryptic variation. Layered sequences of syenitic rocks total c. 3500 m. The compositional range is extended by late-stage minor intrusions of microsyenite and peralkaline granite. The principal cumulus minerals are feldspar (Ab₄₀An₆₀ to Or₄₅Ab₅₁An₄); olivine (Fo₅₆ to Fo₁) and clinopyroxene (Di₇₀Hd₂₇Ac₃ to Di₆Hd₉₀Ac₄ followed by an abrupt change of trend towards Di₃Hd₇₈Ac₁₉ in the layered series and nearly pure aegirine in some peralkaline residues). Intercumulus phases are amphibole (hastingsite to ferro-edenite to ferro-actinolite in the layered series with riebeckite to arfvedsonite in some associated granites) and biotite (annite₃₁ to annite_98.5).