MID-MEETING FIELD TRIP FOR ALL Tuesday, June 11, Half-Day Field Trip: Homestake Open Cut and Sanford Underground Research Facility

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MID-MEETING FIELD TRIP FOR ALL Tuesday, June 11, 2013 Half-Day Field Trip: Homestake Open Cut and Sanford Underground Research Facility This field trip is included in the general registration fee.

1 MID-MEETING FIELD TRIP FOR ALL Tuesday, June 11, 2013 Half-Day Field Trip: Homestake Open Cut and Sanford Underground Research Facility This field trip is included in the general registration fee. This trip is open to all professionals, honoraries, guests, and spouses. Schedule: 7:00 7:45 am Breakfast: Pine Crest Ballroom C 7:45 8:00 AM Bus loading at main entrance to hotel 8:00 AM Bus departure Noon Lunch will be served at the Roundhouse Restaurant in Lead 1:15 PM Return to the Lodge at Deadwood We will travel 5 miles to Lead and the Open Cut of the former Homestake Gold Mine. Approximately 0.5 mile across and 800 to 1,200 feet deep depending on where you measure from, the Open Cut is only a small surface expression of the subsurface of the former mine which is approximately 0.5 mile wide, 3.1 miles long, and greater than 8,000 feet deep. The Homestake Gold Mine operated almost continuously from 1877 to 2002 and produced more than 40 million ounces of gold. It was the deepest operating mine in the Western Hemisphere when it closed due to low gold prices, low grade ore, and high operating costs. Homestake Mining Company worked with the State of South Dakota during the mine closure to ensure that it could be reopened as a deep underground science and engineering laboratory. The underground workings of approximately 370 miles of underground drift in addition to some surface property and buildings were donated to the State of South Dakota to enable creation of an underground laboratory. The trip will continue for another 3 miles to the Sanford Underground Research Facility in Lead. This facility will advance our understanding of the universe by providing laboratory space deep underground, where sensitive physics experiments can be shielded from cosmic radiation. The facility also hosts experiments in other disciplines including geology, biology, and engineering. Presently, experiments at a depth of 4,800 feet are searching for dark matter and an extremely rare form of radioactive decay called neutrinoless double-beta decay. Two shafts, named the Ross and Yates (each about a mile deep), are presently the main access points to the underground. Our trip will include a presentation about the underground laboratory and will take us through some of the surface facilities near the Yates shaft. Lunch will be served at the Roundhouse Restaurant in Lead which is approximately 1.5 miles from the Sanford Underground Research Facility. The restaurant building was constructed in 1901 and was a functioning railroad roundhouse until What to wear: No open-toed shoes. Casual dress; comfortable walking shoes or hiking boots; jacket; hat; sunglasses What s provided: Bottled water; Lunch at the Roundhouse Restaurant June averages for Lead: High temperature: 72 F Low temperature: 49 F Precipitation: 3.57 inches

Photo from Sanford Underground Laboratory The view above is looking southeast at the town of Lead, South Dakota, from the northwest rim of the Open Cut.

The headframes standing above the Yates shaft (tall white structure toward the left of the photo) and the Ross shaft (near the right side of the photo) are visible.

2 Photo from Sanford Underground Laboratory The view above is looking southeast at the town of Lead, South Dakota, from the northwest rim of the Open Cut. This photo was taken nearby to where we will stop on our field trip. The headframes standing above the Yates shaft (tall white structure toward the left of the photo) and the Ross shaft (near the right side of the photo) are visible. These two headframes are approximately ½ mile apart. The foreground in the photo above shows part of the Open Cut created in the removal of ore during mining. We will visit the headquarters of the Sanford Underground Research Facility located in the reddish-brown building just to the right of the Yates headframe (also shown in the photo below). Photo from Sanford Underground Laboratory

3 Aerial view of the Open Cut, looking northwest Photo from Our field trip will stop on the north rim (red arrow) of the Open Cut

4 Photo by M.D. Fahrenbach Above and below are pictures of the Nordberg conical winding drums, called bicylindro-conical double-drum hoists, which have a large and a small radius. Each drum is grooved to wind 5,600 feet of 1-7/8 diameter steel cable Photo by M.D. Fahrenbach

5 One of the drum hoists and a hoist operator station Photo from Sanford Underground Laboratory Hoist operator station Photo by M.D. Fahrenbach

8000 level City of Lead Image modified from cross section provided by Homestake Mining Co.

6 Homestake Open Cut Yates shaft Ross shaft No. 5 shaft 4850 level ROSS HEADFRAME YATES HEADFRAME No. 5 SHAFT 5999 : water level on Feb. 22, 2013; Blue shading shows flooded portion of the former mine level City of Lead Image modified from cross section provided by Homestake Mining Co. This image shows nearly all of the approximate 3.1 miles of mine length as measured in plan view and all of the approximately 370 miles of drift ( horizontal passages) throughout the approximate 0.5 mile of mine width. Homestake mine long-section

Montour No. 10 (Bob Ciminel 2012)

Montour No. 10 (Bob Ciminel 2012) As we continue eastward from Montour No. 4, we reach Library Junction at Mile post 35.08. The west leg of the wye takes us onto the Library Branch. After crossing Library