A
terrane in
geology is a shorthand term for a "
tectonostratigraphic terrane", which is a fragment of crustal material formed on, or broken off from, one
tectonic plate and
accreted or "
sutured" to crust lying on another plate. The crustal block or fragment preserves its own distinctive geologic history, which is different from that of the surrounding areas – hence the term "exotic" terrane. The
suture zone between a terrane and the crust it attaches to is usually identifiable as a
fault.