Definition of "sal"

As the sals were cut in the lower foothill districts the loggers looked towards the mountains in their search for other hardwood timber.

1989, Thomas Weber, Hugging the trees: the story of the Chipko movement, page 18

Wegener bases his theory of the drifting continents on the assumption that there are two distinct levels to be taken into account, the surface of the masses of "sal" which form the continents and the surface of the "sima" in which they float.

1923 March, G. Vibert Douglas, A.V. Douglas, “Note on the Interpretation of the Wegener Frequency Curve”, in Geological Magazine‎, volume 60, number 3, Cambridge University Press, page 108