Columnar basalt

A wee while ago I posted a picture of Dunsapie hill which is comprised of Dunsapie basalt from the Lion's Haunch, one of the five vents that make the Arthur's Seat volcano.

This rocky outcrop also consists of Dunsapie Basalt and has formed these fabulous columns. It lies to the west of the vent and is known as Samson's Ribs.

The volcano was active during the early carboniferous period about 345 million years ago. Hard to imagine all the time that has gone by since then. Fossils of the tree ferns and other exotic plants that lived during those balmy times are still preserved in some places.

My geology book describes Samson's Ribs as having a "slaggy top" and who am I to argue?