""Aids to Identification of Geological Formations"" is a book written by Johan A. Udden and first published in 1919. The book is a comprehensive guide to identifying different geological formations, and it is intended for use by geologists, students, and anyone interested in the study of geology. The book covers a wide range of topics, including the classification of rocks, the identification of minerals, and the interpretation of geological maps. It also includes detailed descriptions of various geological formations, such as sedimentary rocks, igneous rocks, and metamorphic rocks, along with illustrations and photographs to aid in their identification. Udden's work is considered a classic in the field of geology, and it remains a valuable resource for anyone interested in the study of the earth's geological history.This scarce antiquarian book is a facsimile reprint of the old original and may contain some imperfections such as library marks and notations. Because we believe this work is culturally important, we have made it available as part of our commitment for protecting, preserving, and promoting the world's literature in affordable, high quality, modern editions, that are true to their original work.