[MAP] - Lot 87

[MAP] SPURR, Josiah Edward. Atlas to Accompany Monograph XXXI on the Geology of the Aspect District Colorado. Washington, Julius Bien & Co. 1898. Lithographed in color. One atlas in-folio, publisher's boards, gilt title on front cover + one text volume in-4 in publisher's boards; 27 chromolithographed maps and sections (2 on double page), complete. A fine copy. The atlas comprises 27 maps (including 2 double-page spreads) showing the topography and geology of the mountains around Aspen, including maps for Aspen, Tourtelotte Park, Hunter Park, Lenado, Smuggler Mountain, etc. The atlas accompanies the monograph by Samuel Franklin Emmons (1841-1911), chief geologist in charge of the Colorado Division of the United States Geological Survey. Emmons is also known for having revealed the famous Colorado diamond fields deception in 1872. The maps are lithographed, some in color (chromolithography) to highlight the geological units. The atlas brings together geological maps superimposed on basic topographic surveys (fine topography) for geological interpretation in context. The scale of the maps varies: some sheets are at a scale of half a mile to one mile per inch (i.e. fine scales to cover localized areas). Provenance: Société Géologique de France.