CONTENTS. 



Page. 



Letter to the Secretary j 



PART I.— GEOLOGY, MINERALOGY, AND MINING INDUSTRY. 



Report of F. V. Hayden, U. S. geo]of?ist 17 



Chapter I. Remarks on survey — The geological ieatiires of the east slope of 

 the Colorado range of the Rocky Mouutaius from Cache a la Poudre 



River southwards to Pike's Peak 17 



Chajtter II. Colorado Mouutains, South Park, Park range, Upper Arkansas 



Valley 3G 



Chapter III. Sawatch range — Morainal aeposits of Taylor's Creek — Elk 



Mountains, etc 53 



Chapter IV. From Elk Mountains to Middle Park 70 



Middle Park 81 



Report of Arch. E. Marvine, assistant geologist directing the Middle Park divi- 83 



sion Chapter I. Area, natural divisions, and principal topographical features. 85 



Principal topographical features — main divide 86 



Principal topographical features of the eastern slope 88 



Principal topographical features of the Middle Park 90 



General geological divisions ■. 92 



Chapter II. The sedimentary rocks east of the Front range 93 



The Trias 95 



The Jurassic 98 



Section of Jurassic beds near the Bear's Church, Big Thompson Creek — Dr. 



F. V. Hayden, Third Annual Report, 1869, reprint, p. 125 98 



Section of Jurassic beds exposed near Saint Vrain's Creek. — William H. 



Holmes 99 



Section of Jurassic beds exposed in Bear Canon. — William H. Holmes 99 



Section ot Jurassic beds exposed near Ralston Creek. — William H. Holmes 99 



Section of Jurassic beds exposed near Bear Creek. — William H. Holmes. . . 100 



The Cretaceous No. 1 100 



Section of Cretaceous No. 1 at Bear Canon 101 



Section of Cretaceous No. 1 near the South Platte River. — Dr. A. C. Peale. 101 



Cretaceous No. 2 101 



Section of Cretaceous No. 2 at Little Thompson Creek '. 102 



Section of Cretaceous No. 2 at Bear Caiion 102 



Cretaceous No. 3 102 



Section of the lower beds of Cretaceous No. 3 at Bear Canon 103 



Section of the lower beds of Cretaceous No. 3 at Little Thompson Creek.. 103 



Cretaceous No. 4 and No. 5 103 



The Triassic beds 105 



The Lignitic formation 106 



Section of the Lignitic strata at Golden City, Colorado Territory, from a 



cross-section made by E. L. Berthoud, civil engineer 109 



Section of artesian well near Denver City, by Eli Brooks, engineer 109 



The Coal series 110 



Characters and appiications of the Lignitic coals 110 



Table A. Proximate analyses of Western Lignitic coals 112 



Table B. Ultimate analyses of Western Lignitic coals adopted from R. 



W. Raymond ." 114 



Physical characters of the Lignitic coals of the plains 116 



Applications * 117 



Distribution and developments of the Liguitic coal 119 



The various coal-openings 120 



Section of strata in sliaft, fourteen miles east of Denver. — E. B. Mally . . - - 121 

 Section of the Liguitic beds at the Marshall mine, Colorado. — Dr. F. V. 



Hayden, 1869 • 123 



Post-Lignitic formations 128 



The eruptive rocks of the plains 129 



General structural features of the mountain-border re>'ioii 131 



