Toomre diagram (LSR-corrected) for our sub-sample of high-α stars, colour-coded according to their ⁷Li abundance (see vertical bar on the right). Constant total space velocities with respect to the LSR of V_tot = 85 and 210 km s⁻¹ are marked with dashed curves. Low-α, metal-rich α-rich, and super metal-rich solar-α stars (not shown to avoid overcrowding) are consistent with thin-disc kinematics.