nprofile1qy2hwumn8ghj7un9d3shjtnyd968gmewwp6kyqpq33k4fr6pw6d4s8k3j62pvt6u62a830ddp9xmwsnxavlzw2ep52ys9qc5l4 (nprofile…c5l4) Seems to be a much older proxy originally used on clays. I can't find the original paper where the use of Ga was introduced, but I don't think it's a stand-in for Al but rather some general weathering flux tracer.
https://www.sciencedirect.com/science/article/pii/S0037073816302767