Geology of titanium and titaniferous deposits of Canada

This report describes the nature of occurrence of the titanium and titaniferous deposits of Canada in general and in detail, outlines their distribution, classification, origin, age, size, and grade, and points out the close genetic relationship existing between them and anorthositic rocks. Most of the titanium deposits occur in both massive and disseminated form throughout large, composite, multiple, intrusive anorthositic bodies in eastern Canada. Anorthosite and gabbroic anorthosite or gabbro (troctolitic and noritic) are the two most common and closely related phases of these intrusive bodies, but in places monzonite, syenite, granite, and pegmatite may also be distantly related. The main ore minerals-ferrian ilmenite, titanomagnetite, and titanhematite- occur most abundantly in the gabbroic phases of the anorthosites, but they are also found in the anorthosites proper, and less commonly in the country rocks into which the anorthositic massifs are intruded. These minerals commonly show exsolution textures characteristic of deposits formed at magmatic temperatures, and they may possess self-reversing magnetic mechanisms and hard components of remanent magnetism capable of affecting the direction and intensity of the resulting magnetic fields. The report includes a discussion of the advantages and limitations of magnetic surveys in locating titanium deposits, and suggestions for applying the study of remanent magnetism of occurrences as an aid to geological interpretation. Because of their heavy magnetic character, the iron- titanium ore minerals are readily separated magnetically from their host-rock silicates, and although many of the deposits are of low grade in both iron and titanium they may be readily concentrated. Furthermore, although many of the deposits are too high in titanium to be iron ores (or too high in iron to be titanium ores at present) and the iron and titanium minerals are practically inseparable, some of the deposits consist of iron-titanium mineral intergrowths of such nature that it is possible to separate them magnetically into high iron (titanomagnetite) and high titanium (ilmenite-hematite) concentrates, potential ores of iron and titanium, respectively.