Skip to Main Content

Abstract

Since its discovery in 1891, the Cripple Creek district has produced more than 653 tonnes of Au(21 million oz) from high-grade gold-telluride veins. About99.5tonnes (3.2mi1lion ounces) of gold have been added to the district resource as a result of recent exploration (past 5 years) which has delineated low-grade, near surface disseminated gold deposits that occur as broad zones in permeable rocks adjacent to major structures (pontius, 1992;Harris et sl., 1993). The ore deposits of the district are localized within and adjacent to an elliptical northwest-trending diatreme complex that covers about 18 km2, Although some of the deposits occur within Proterozoic rocks surrounding the complex, most of the ore bodies are spatially associated with Tertiary alkaline igneous rocks and breccias within the complex.

During the most productive mining years beginning in 1893, several comprehensive studies of the Cripple Creek district were conducted that included detailed descriptions of the mineralogy, texture, and field characteristics of each rock type and of the ores (Cross and Penrose, 1895;Lindgren and Ransome, 1906;Loughlin and Koschmann, 1935). Over the past 12 years, selected ore deposit studies have focused on the fluid inclusion characteristics, mineralogy, and alteration of the deposits (Thompson et el., 1985; Saunders, 1986; Nelson, 1989; Seibel, 1991; Burnett, 1995). The close spatial association between the deposits and alkaline igneous rocks, and relatively hot (average of 350±C), hypersaline (>40 wt. % NaCI equivalent) fluid inclusions in quartz from early stages of vein formation (Thompson et sl., 1985) have led many workers to suggest that the ore fluids were magmatically derived (Lindgren and Ransome, 1906; Thompson et sl., 1985; Pontius, 1992).

Figures & Tables

Contents

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal