A
sheeted dyke complex is a normal component of an
ophiolite, a piece of oceanic crust that has been emplaced within a sequence of continental rocks. The
dykes act as feeders for the overlying sequence of extrusive rocks typically
pillow lavas, together forming layer 2 of the
oceanic crust. As each injection of a dyke represents one increment of seafloor spreading, each dyke is normally intruded into earlier dykes. The dykes are typically
dolerites but plagiogranites (
trondhjemites) often form a significant part of the complex.
See also
Dike swarm
References