Is the sidewall cracked? Looks like a hard flex/impact caused the sidewall to crack and the base to delam. If that’s the case - there’s a chance the core is cracked. Any other signs of damage besides just the base pulling away?
Needle, syringe, g flex epoxy, and clamps. Allow skis to fully dry before beginning. Put that shit in and clamp until fully cured. Sand off any excess that has seeped out.
Curious if anyone has used screws to fix a massive delamination before? I wouldn't trust it for an all mountain ski but park ski, sure.