Annual report . st-Hastings basic intrusives, marked on the maps asbeing doubtfully of Keweenawan age, are more altered or decomposed than the Nipissingdiabase of Cobalt, and may be of about the same age as the lamprophyre dikes of Cobaltand the pillow lavas, post-Sudbury series, of Sudbury. Fragmental rocks, comparablein age with the rocks to which the name Cobalt is applied, have not been recognized ini le out hi a ? ? rn region, The two regions are separated by a territory which is underlain chiefly by graniteand granite gneiss, and in which pro-Cambrian sediments later in age than the Gren
Annual report . st-Hastings basic intrusives, marked on the maps asbeing doubtfully of Keweenawan age, are more altered or decomposed than the Nipissingdiabase of Cobalt, and may be of about the same age as the lamprophyre dikes of Cobaltand the pillow lavas, post-Sudbury series, of Sudbury. Fragmental rocks, comparablein age with the rocks to which the name Cobalt is applied, have not been recognized ini le out hi a ? ? rn region, The two regions are separated by a territory which is underlain chiefly by graniteand granite gneiss, and in which pro-Cambrian sediments later in age than the Grenville6eries are not known to occur. Following the nomenclature usually employed in the description of fragmental rocksnext younger than the Laurentian, both the Hastings and Temiskaming series might becalled, provisionally. Lower Huronian. In the appendix to this report is given a comparative table of the age relations oftie pre-Cambrian rocks of all the areas in Ontario that have been mapped
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectminesandmineralresou
