Pre-Cambrian Nomenclature

Abstract

The report of the committee of American and Canadian geologists appointed by the surveys of the two countries to compare notes in the field and decide upon a suitable nomenclature for the pre-Cambrian formations of the Upper Lakes, forms an important landmark in the geology of that region. While it is evident from the report itself that the results attained represent a compromise, not perhaps altogether satisfactory to either party, in the long controversy which has been waged over the relationship of these complex and difficult formations, yet it is to be hoped that, at least in its broad lines, the proposed nomenclature will be accepted by future workers in the region, putting an end to the confusion which has reigned. The position and reputation of the members of the committee give their decisicons great weight, and doubtless their nomenclature is the best that could be framed to reconcile the two points of view. Accepting it as such it may still not be amiss to discuss certain features of the report, as they appear to one who has worked over much of the region on the Canadian side. The brief summing up of the results of their field-work in the various districts visited is of use as showing the ground covered by the committee, and the materials which they brought to bear on the solution of the problems of the pre-Cambrian; and in general their conclusions seem quite justified, in spite of the short time which could be devoted to any one place. Several members of the committee had of course previously done a large amount of work in the critical localities and were thoroughly familiar with the field relationships. It is to be regretted, however, that so few of the characteristic sections of the Rainy Lake region were visited, and that the important Michipicoten district was not visited at all. In the latter case Professors Van Hise