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Skaergaard Intrusion :sunrise_over_mountains: - Coggle Diagram
Skaergaard Intrusion
:sunrise_over_mountains:
Greenland
Most studied in the word
Intruded during the tertiary
When North Atlantic opened up
Magma chamber for basalt magma
3 major units
Maginal Border
Layered series
Upper border series
Marginal Border
Chilled margin
Fine crystal size
Cooled rapidly
No longer the same composition as original magma
Contaminated by country rock
Crystals grew inwards from the sides of the intrusion
Layered series
Rhythmic layering
Crystal settling interrupted by periodic large scale convection
Filter pressing causes the expulsion of the differentiated liquid
Convention mixes the magma
Sequence of denser crystals beneath lighter plagioclase
Denser
Olivine
Pyroxene
Deposited by gravity settling
Process is repeated
Each cycle
magma is more evolved
Removal of crystals
Cumulates form from the floor
igneous rock formed by the accumulation of crystals due to gravity settling and are typical of layered intrusions
Upper border series
Thinner
Mirrors the 2500m layered series
Layers that crystallised from the top down