A study of the geology in the vicinity of Corporation Quarry, Mount Royal, Montreal, Canada.

Corporation Quarry is on the northern edge of the Mt. Royal intrusive plug. Three ages of intrusive rock, - essexite, syenitic breccia, and nepheline syenite, are represented here, as well as seven ages of dykes. The following geological sequence was observed in the Quarry; beginning with the oldest rocks:- 1. Trenton limestone.2. Essexite,- coarse grained, melanocratic, varying greatly in texture. Composed essentially of titaniferous augite, magnesiohastingsi te arnphi bole, calcic plagioclase ranging from An85 to An30, with accessory olivine, titanite, magnetite and apatite. 3. Alkalic lamprophyre dykes;- black, fine-grained, composed essentially of needles of magnesiohastingsite set in a ground mass of alkali feldspars. Their relation to the essexite is not very definite. [...