Mineral deposits associated with alkalic rocks of major economic importance to Colorado’s mining industry. Includes survey of alkalic rocks, studies of ore deposits associated with alkalic rocks by mining districts (Central Front Range Mineral Belt, Cripple Creek District, State Line Kimberlite District, La Plata District, Hahns Peak District, Iron Hill Alkalic Complex, Silver Cliff and Rosita Hills District, Wet Mountain Alkalic Complexes, Ralston Buttes District, and other alkalic provinces), discussion of geological setting, geochemistry, economic geology, exploration and production history and references. 137 pages. 47 figures. 1 appendix. Digital PDF download. RS-35D
From the preface:
Alkalic igneous rocks in Colorado formed in a wide variety of tectonic settings-from the Cambrian intrusive complexes of the Wet Mountains to the late Tertiary alkalic basalts of central Colorado. They host mineral deposits as economically important as the Cripple Creek gold district, which has produced over 21 million ounces of gold since its discovery in 1891. The following chapters discuss the principal alkalic igneous complexes that are associated with economically significant mineral deposits. The final chapter describes several other alkalic igneous provinces of the state not associated with significant economic mineral deposits.
Whole rock geochemical data and the CIPW normative compositions are included as tables in the appendix and are summarized in figures at the end of each chapter. References for regions are also included at the end of each chapter.