In a landscape where megalithic structures, field boundaries, and glacial erratics all compete for attention, the decision to record a stone group as anomalous suggests that whoever examined it found it difficult to place within the usual categories, neither a recognisable monument type nor simply a natural scatter of rock.

The term anomalous stone group is used in Irish archaeological classification when a collection of stones displays some evidence of human intent or arrangement, but does not conform clearly enough to established monument types such as a stone circle, a cairn, or an alignment to be recorded under one of those headings. Galway's geology and its long history of human settlement, stretching back through early medieval, Bronze Age, and Neolithic periods, means that ambiguous stonework is not uncommon, but it is rarely less interesting for being ambiguous. Marblehill itself, as a place name, carries its own suggestion of a landscape that has attracted attention over centuries, though whether that name reflects geology, land ownership, or something else entirely is not clear from what survives in the record.