This colorful geological map focuses on the United States, but also includes a good portion of Canada and the Baja. It identifies twelve different geological units by color. This updated German edition by Justus Perthes presents much of the same information as Marcou's original 1853 map but extends geological coverage to the Pacific and eliminates the geological profile across the top. The Copper trap previously shown in the Wind River Mountains is not depicted here. An uncommon edition of Marcou's scarce map.

The Marcou reference book that discusses this map is also available in this auction, lot 853.

References: Marcou #48.

Condition: B+

Fine impression and bright color with a few spots of foxing, mostly in the blank margins. Issued folding.