Dolomitization processes in the Palaeozoic horizons of Manitoba
Birse, Donald John
The material contained in this thesis is the result of an investigation made on rocks from certain Manitoba palaeozoic horizons in which dolomitization processes have been active. A note has also been added on a mottled drift boulder from Gimli, Manitoba. Normal dolomite, CaMg(CO3)2 consists of 54.35% calcium carbonate, and the remainder, 45.65% magnesium carbonate. Pure dolomite has rarely been found, dolomite with impurities of siliceous and argillaceous material together with iron and related minerals more commonly occuring. In a great many dolomites the percentage of calcium is far in excess of the normal amount and at times it is difficult to draw the boundary between limestone and dolomite. This paper will refer to those rocks composed entirely of dolomite crystals as "dolomites", those with dolomite and calcite crystals as "dolomitic limestones", and those with approximately 2% of magnesium carbonate, but with no dolomite crystals developed, as "magnesian limestones.".....