Brown Bluff is divided into four stages: pillow volcano, tuff cone, slope failure, and hyaloclastite delta; and into five structural units.

[1] Brown Bluff has a 1.5 km-long (0.93 mi) cobble and ash beach rising increasingly steeply towards towering red-brown tuff cliffs embedded with bombs and tephra.

The cliffs are heavily eroded, resulting in loose scree and rock falls on higher slopes, and large, wind-eroded boulders on the beach.

Lichens in the genera Xanthoria and Caloplaca have been recorded on exposed boulders from the shoreline to an elevation of 185 m (607 ft).

Brown Bluff is a one-half-mile-high (0.80 km) cliff of volcanic rocks consisting of a tuya or moberg, which is a volcano erupted under an icecap.