The name is derived from Aberystwyth in northern Ceredigion where the strata are well exposed in coastal cliffs.

The rocks of the Aberystwyth Grits Group have also previously been known as the Aberystwyth Grits Formation[1] These rocks are exposed, along the Cardigan Bay coast both to the east and west of New Quay and northwards through Aberaeron and Aberystwyth to just short of Borth.

Much of the eastern boundary is defined by the Bronnant Fault.

[2] The Group comprises several hundred metres thickness of mudstone and sandstone turbidites laid down in the marine Welsh Basin during the Llandovery epoch of the Silurian period.

Palaeocurrents indicating a source in the southwest have been recorded from throughout the group.