SOCIETY OF ECONOMIC GEOLOGISTS, INC.
GUIDEBOOK SERIESVolume 46
Prepared for the Society of Economic Geologists Field TripSeptember 26, 2014
Field Trip LeaderT. Brown, S. Diakov, and S. McAnally
T. Brown, Editor
The Cripple Creek Mining District of Colorado in 2014
GUIDEBOOK SERIES
OF THE
SOCIETY OF ECONOMIC GEOLOGISTS, INC.
Guidebook 46
ISSN 1547-3090
ISBN 978-1-629490-50-2
CD-ROM
ISSN 1547-3104
ISBN 978-1-629490-51-9
Online
ISSN 2374-6955
ISBN 978-1-629494-83-8
Digital version (on CD-ROM or as a pdf file) available from
Society of Economic Geologists, Inc.
7811 Shaffer Parkway
Littleton, Colorado 80127
Tel. 1.720.981.7882
Fax: 1.720.981.7874
Bookstore: www.segweb.org/store
Publication date: September 2014
CONTENTS
Preface Tim Brown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ii
Road Log for the Cripple Creek Field Trip Tim Brown. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Geology of the Cripple Creek district Part I;
General summary of geologic features and regional setting [Reprint] Eric Jensen and Mark Barton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
Geology of the Cripple Creek district Part II;
Time-space synthesis of magmatic and hydrothermal activity [Reprint]
Eric Jensen and Mark Barton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Geologic map of the Cripple Creek District (Lindgren and Ransome, 1906) and the field trip
stops. The geologic contact between the Oligocene volcanic rocks and the Precambrian rocks is
shown by the red line.
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PREFACE
The Cripple Creek Mining District is world-class district by any definition (ounces produced, dollars
generated, publications authored, etc.). The district, located 20 air miles (32 km) west of Colorado
Springs, Colorado, has produced over 24 million ounces of gold (750 tonnes) since its discovery in
1891. Current reserves (year end 2013) stand at 4.7 million contained ounces (146 tonnes) and
exploration efforts continue to search for additional resources.
The bulk of the gold mineralization has been produced from narrow, high-grade veins hosted in an
Oligocene, alkaline, diatreme-intrusive complex. Gold has also been produced from mineralization
hosted by the Precambrian rocks where the vein systems were strong enough to penetrate from the
diatreme. More recently, gold has been produced by bulk mining methods in the low-grade haloes
around the vein systems.
The recent district publications include a PhD. dissertation completed by Eric Jensen through the
University of Arizona in 2003. The document is too big to be included in the guidebook but
interested readers are encouraged to take advantage of this work. Papers by Eric Jensen and Mark
Barton (2007) are the most recently published works for a GSA/SEG field trip in October 2007.
They have both been included in this guidebook with permission.
The mine is operated by Cripple Creek and Victor Gold Mining Company, a wholly owned
subsidiary of AngloGold Ashanti, Ltd. They are gratefully acknowledged for allowing the
publication and the tour.
TIM BROWN
August 2014
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