Note 344 — Chapter XLIII · THE BOSSES AND SHEETS OF GABBRO
Reading edition
Though this and the other bosses are here spoken of as consisting of gabbro, it will be understood that this rock only constitutes the larger portion of their mass, which includes also dolerites and other more basic compounds, together with involved portions of the plateau-basalts and masses of agglomerate which probably mark the position of older vents.