Hi Alison, The largest image of a soldier is in the 4th image. It seems to have toothed mandibles. If so, not Coptotermes. Were these termites in a mound, or in soil, or rotting wood?
Any chance of a closer view of the soldiers? Maybe the impression of toothed mandibles was created by grains of soil covering some parts of the mandibles, or maybe the impression was real. i could not decide