The official record for interstellar impacts is a blank page so let me try to fill in the dots.
Because of the incredible pressures within the subsurface interstellar impact plume, when the magma column rises up it tends to blowout and rupture the surface. The magma column explodes outward lifting up a conical plug of the country rock. The magma flow supports a conical plug leaving a core of sediments and molten sediments surrounded by a ring of (usually) basaltic magma.
This creates an unusual surface structure called a ring dike.