CONTENTS. XI 



Paet I — The Pre-Cretaceous movement — continued. 



The Cretaceous uplift 315 



Irruptions accompanying the northeast uplift 318 



The Post-Cretaceous deposits , 319 



Relations of the Wichita Mountains to the Central Paleozoic area 319 



Part II — Economic Geology 329 



Precious metals 330 



Gold 330 



Silver 332 



Base metals 334 



Copper 334 



Lead . 339 



Zinc 344 



Tin 345 



Manganese ores 345 



The iron ores 347 



Magnetites 347 



Hematites 353 



Hydrated iron ores 359 



Rare minerals and precious stones 361 



Building materials 364 



Refractory materials 374 



Materials for paints 376 



Miscellaneous economic products 376 



Part III — List of minerals coUected by the Survey from the Central Mineral District. . 379 



