Homestake Mining Company -- McLaughlin Mine
This geology section was developed by Dean Enderlin as part of the closure plan for Homestake's McLaughlin mine and can be found as part of the 2000-2001 annual report.

The McLaughlin deposit is the largest gold discovery of the 20th century in California. The historic ore reserve exceeded 4 million ounces of contained gold, from which approximately 3.3 million ounces will be recovered. The McLaughlin deposit is a world-class gold orebody, and one of the world's finest examples of a hot springs-type epithermal precious metals system. When discovered, the deposit was remarkably well preserved, with an intact siliceous sinter capping the central portion of the mineralized outcrop. The subaerially deposited hot springs sinter terraces marked the paleosurface of the Pleistocene hot springs that formed the deposit. The presence of sinter was especially important in demonstrating that this was a fully preserved epithermal system from the top down… a rarity in deposits such as this, and an opportunity for scientists around the world to study this fascinating geologic feature as it was mined.

Numerous geology-related technical reports and several graduate theses have been published on the McLaughlin deposit. A number of previously published geology reports are included in the Technical Reports section of the Closure Plan. The reader is encouraged to read these reports for in-depth discussions of the technical aspects of the McLaughlin mine geology. Contact Reserve Staff to obtain these reports.

The links below will guide you through some of the visual highlights of the McLaughlin mine geology. We are fortunate to have an excellent photographic record of the deposit, and these pages are provided to offer the reader a small glimpse at the amazing geology of the McLaughlin mine and the surrounding Knoxville Mining District.

Note: The following pages are graphics-intensive, so it may require a few "geologic" seconds to fully load.


Geology of the McLaughlin Deposit

The San Quentin Sinter

McLaughlin Gold!

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