diapir
noun
di·a·pir ˈdī-ə-ˌpir 
: an anticlinal fold in which a mobile core has broken through brittle overlying rocks
diapiric
ˌdī-ə-ˈpir-ik
adjective 
Word History
Etymology
French, probably from Greek diapeirein to drive through, from dia- + peirein to pierce; akin to Greek poros passage — more at fare
First Known Use
1918, in the meaning defined above