Post shield stage
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Post-Shield Stage refers to a stage of growth in the life of a volcano, referring to a late period in the life of a shield volcano. The characteristics of the shield volcano, such as gently sloping sides, remain with the volcano.
A Post-Shield volcano becomes dormant, or less likely to erupt. The mixture of the gases and minerals changes from a tholeiitic basalt back to a stronger, more dense, alkalic basalt. This makes the lava more explosive and more dangerous.
The lava produced tends to be more dense and viscous. The chance of an eruption is lower, but when an eruption does occur, the viscosity of the magma increases the chances of an explosive eruption.
There are relatively few post-shield volcanoes.