You've recovered the materials that will help connect the obelisk to the Sundial. Now, you must bring these back to the obelisk in order to modify it. Bank the recovered Sundial Components at the obelisk.
"A few small modifications and adjustments should restore the obelisk's functionality and connect it to the Sundial. Time is of the essence, Guardian. If time splits on the Shore as it has on Mercury, I know many individuals here who would exploit that disaster." —Transmission from Osiris
Legendary Quest Step
2019.12.10 (Season of Dawn)