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Sill (geology)
Tabular intrusion between older layers of rock / From Wikipedia, the free encyclopedia
In geology, a sill is a tabular sheet intrusion that has intruded between older layers of sedimentary rock, beds of volcanic lava or tuff, or along the direction of foliation in metamorphic rock. A sill is a concordant intrusive sheet, meaning that it does not cut across preexisting rock beds. Stacking of sills builds a sill complex[1] and a large magma chamber at high magma flux.[2] In contrast, a dike is a discordant intrusive sheet, which does cut across older rocks.
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