The Bull Arm Formation is a volcanic formation cropping out in Newfoundland, the youngest of the Musgravetown Group.

[3] It is defined as everything between the first and last volcanic horizon, with a recognition that some sandstones will be interbedded, and its start and finish may vary across the region depending on how widespread volcanic horizons are in practice.

[4]

This article about a specific stratigraphic formation is a stub.

You can help Wikipedia by expanding it.