I think the face of 'Geology' bears considerable similarity to Carrick himself and I have a suspicion that this is a self-portrait. Carrick's daughter Elizabeth disagreed with me on this, but I feel it would have been fitting for this sculptor and master stone carver to portray himself in such a way. Carrick also had a good sense of humour and I think this may have been a bit of fun.
The arrangement and pose of the figure itself is a little reminiscent of Rodin's 'The Thinker', perhaps this is Carrick the stone carver's answer to Rodin the modeller.