Macbook pro 1398 can't erase new SSD

[zeon]

Trying to erase newly installed crucial 2TB SSD but diskUtility doesnt let me erase plus calls the disk 'macOS Base System' and shows it as 1.28GB full even though its empty???
(Im booting off a seperate USB drive)
Any help welcome..

 

[MacsBug]

The macOS Base System is a disk image with the OS on it that is on the USB flash drive.

In Disk Utility under the View menu make sure that you have Show All Devices selected.

If you do not see the Crucial drive, it may need to be initialized in an external enclosure before being put in your Mac.