Abstract: The noble gas composition for the individual step-crushes of the two plume-influenced MORBs. MORB samples are from the Discovery Ridge segment of the South Atlantic mid-ocean ridge.These new neon isotopic measurements from deep mantle plumes reach values up to 13.03±0.04 (2 sigma). The measured 20Ne/22Ne ratios are demonstrably higher than solar wind irradiated material and CI chondrites, requiring the presence of nebular neon in the deep mantle. Furthermore, these new measurements allow us to determine a primordial mantle plume 20Ne/22Ne ratio of 13.23±0.22 (2 sigma), which is indistinguishable from the nebular ratio, providing robust evidence for a reservoir of nebular gas preserved in the deep mantle today.