2003 On-the-Rocks Field Trips

Title: 2003 On-the-Rocks Field Trips
Author: Fred Mark
Publication: The Outcrop, April 2003, p. 14

Mark your calendar for the six On-the-Rocks field trips that are planned for the summer of 2003. The details and registration information for each trip will be printed in the Outcrop issue before the trip.

Aquifers of the Denver Basin — Bob Raynolds, May 31 , 2003. The trip will visit outcrops of the major bedrock aquifers in the Denver Basin, and will examine and discuss an integrated surface-to-subsurface interpretation of the water-logged lithologies that make up the key aquifers in Douglas County. Additional discussion will focus on depositional environment, water reservoir extent, quality, and potential for future development. There will be an emphasis on the heterogeneous distribution of underground water resources.

Bicycle Trip Along the Mineral Belt Trail, Leadville, Colorado — Fred Meissner, June 28, 2003, and optional second day June 29, 2003. The Leadville Mining District has a great and glorious history of precious and base metal ore production. Following the discovery of placer gold in 1860, replacement and vein deposits were found in lower Paleozoic carbonates. Over 100 mines were developed and several large smelter complexes were erected. The Mineral Belt Bicycle and Hiking Trail, which forms a 12.5 mile loop that skirts Leadville and ascends hills in the mining area east of town, has recently been developed along a portion of the extensive system of abandoned railroad beds that once provided access and transportation service to the mines. The field trip will start at a convenient trailhead in Leadville and use bicycles to traverse the route. Geology and history of the area will be discussed at stops along the way. For those wishing to stay overnight in Leadville, arrangements may be made for a group visit to the National Mining Museum and Hall of Fame on Sunday, June 29.

Henderson Mine, East Side Surface and Underground Tour — Bob Golden, July 19, 2003. The Henderson is the last major underground hard rock mine in Colorado. It produces about 2,000,000 pounds of molybdenite from a world class mineral deposit. The tour will begin with a visit and discussion of surface reclamation at the nearby Urad Mine followed by a discussion of the Henderson ore deposit and mining methods. The surface facilities tour will include ventilation and hoist facilities. The underground tour will include haulage ways that accommodate 80-ton trucks, a block cave and stope production area, development drift, underground crusher and the tail of the 10+ mile underground haulage belt to the mill on the west side of the divide.

Gold and Glaciers — Beth Simmons, August 9, 2003. A trip into the cold and the golden past. The trip will include a discussion of Front Range geology along Golden Gate Canyon, with historical stops to discuss early mining history at the Gregory Diggins, the ghost town of Nevadaville, and the masonic cemetery. After contacting the dead, the trip will proceed through Russell Gulch and down Virginia Canyon with lunch at Beau Jo’s. Discussion of glacial geology will include glacial history and features from Lawson to Berthoud Pass along with a history of US Highway 40.

Unaweep Canyon and Tertiary Geomorphology — Pete Varney, September 13, 2003. Unaweep Canyon is south of Grand Junction between the towns of Whitewater and Gateway. The canyon is visually remarkable because of its depth and near-vertical sides. Your first thought on seeing it may be that the small stream that meanders in the bottom of the canyon could not possibly have cut it. Then too, drainage out of Unaweep is both to the east and west. There is a mystery here. The trip will examine evidence that Unaweep Canyon is an abandoned channel of the Gunnison and, possibly, the Colorado (Grand) River. It is a fascinating story about Tertiary geomorphology with an uplifting conclusion.

Tour of the American Gypsum Mine and Wall Board Plant at Gypsum, Colorado — Steve Onorofski, October 2003. The tour will include a visit to the wallboard plant located along 1-70 in Gypsum, Colorado and the nearby mine that supplies the plant. Gypsum for the plant is mined from the Pennsylvanian Eagle Valley Formation. The mine produces about 450,000 tons of gypsum annually using pavement-profilers. The On-the-Rocks Committee is looking for someone to lead a trip on the recent volcanics at Basalt, Colorado in conjunction with this trip. Please contact Fred Mark at fredmark@qwest.net if you are willing or know of a potential leader.