Figure F43. Digital photomicrograph (plane-polarized light) of internal contact in dolerite. Glassy dolerite in top left (with pseudomorphs after olivine microphenocrysts at upper left) intrudes crystalline dolerite (bottom right). Rounded blebs of the intruding rock are incorporated within the crystalline dolerite (plane-polarized light) (interval 180-1109D-51R-4, 22-24 cm).