Grandview Mine
Encyclopedia
The Grandview Mine, also known as the Last Chance Mine, was operated by Pete Berry from 1892 until 1901 in what later became Grand Canyon National Park
. The Grandview Mine Historic District includes what remains of the mine shafts and machinery as well as the ruins of a stone house and sleeping shanty. Physical evidence, including low stone walls and construction debris, suggests that several wood structures were also originally present on the site.
Pete Berry established Last Chance Mine on Horseshoe Mesa in 1892. He constructed the four-mile Grandview Trail
down to the copper mine, and in 1893 began hauling ore out by mule. Although the ore was over 70% pure copper and won a prize at the Columbian Exposition in Chicago
, the mine did not prove profitable, and in 1901 Berry and his partners sold it to the Canyon Copper Company, who operated it until 1907. The mine was then acquired by William Randolph Hearst
, who sold it to the National Park Service
in 1940.
The mineralization at the mine is secondary copper
minerals in a breccia
zone along a monocline
flexure in Navajo Sandstone
. Redwall Limestone is bleached, brecciated and marbleized. Grandview is the type locality
for grandviewite, a copper aluminium silicate
. Grandview produced exceptionally fine mineral
specimens of cyanotrichite
, brochantite
, chalcoalumite, and many other copper and uranium
minerals. These specimens are now rare, as mineral collecting
is not permitted in the National Park.
In 2009, the mines were gated to protect bat
roosts, support on-going bat research, preserve historic mine resources, and promote visitor safety. The gating project was done by Mine Gates, Inc., with support from Grand Canyon National Park
, Bat Conservational International
, and Freeport-McMoRan
. Details of the mine site, as well as manufacturing and installation of each bat gate are documented on the MineGates site.
Grand Canyon National Park
Grand Canyon National Park is the United States' 15th oldest national park and is located in Arizona. Within the park lies the Grand Canyon, a gorge of the Colorado River, considered to be one of the Wonders of the World. The park covers of unincorporated area in Coconino and Mohave counties.Most...
. The Grandview Mine Historic District includes what remains of the mine shafts and machinery as well as the ruins of a stone house and sleeping shanty. Physical evidence, including low stone walls and construction debris, suggests that several wood structures were also originally present on the site.
Pete Berry established Last Chance Mine on Horseshoe Mesa in 1892. He constructed the four-mile Grandview Trail
Grandview Trail
The Grandview Trail is a hiking trail located on the South Rim of the Grand Canyon National Park, located in the U.S. state of Arizona.-Description:...
down to the copper mine, and in 1893 began hauling ore out by mule. Although the ore was over 70% pure copper and won a prize at the Columbian Exposition in Chicago
Chicago
Chicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...
, the mine did not prove profitable, and in 1901 Berry and his partners sold it to the Canyon Copper Company, who operated it until 1907. The mine was then acquired by William Randolph Hearst
William Randolph Hearst
William Randolph Hearst was an American business magnate and leading newspaper publisher. Hearst entered the publishing business in 1887, after taking control of The San Francisco Examiner from his father...
, who sold it to the National Park Service
National Park Service
The National Park Service is the U.S. federal agency that manages all national parks, many national monuments, and other conservation and historical properties with various title designations...
in 1940.
The mineralization at the mine is secondary copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
minerals in a breccia
Breccia
Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix, that can be either similar to or different from the composition of the fragments....
zone along a monocline
Monocline
A monocline is a step-like fold in rock strata consisting of a zone of steeper dip within an otherwise horizontal or gently-dipping sequence.-Formation:Monoclines may be formed in several different ways...
flexure in Navajo Sandstone
Navajo Sandstone
Navajo Sandstone is a geologic formation in the Glen Canyon Group that is spread across the U.S. states of northern Arizona, northwest Colorado, and Utah; as part of the Colorado Plateau province of the United States...
. Redwall Limestone is bleached, brecciated and marbleized. Grandview is the type locality
Type locality (geology)
Type locality , also called type area or type locale, is the where a particular rock type, stratigraphic unit, fossil or mineral species is first identified....
for grandviewite, a copper aluminium silicate
Silicate
A silicate is a compound containing a silicon bearing anion. The great majority of silicates are oxides, but hexafluorosilicate and other anions are also included. This article focuses mainly on the Si-O anions. Silicates comprise the majority of the earth's crust, as well as the other...
. Grandview produced exceptionally fine mineral
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
specimens of cyanotrichite
Cyanotrichite
Cyanotrichite is a copper aluminium sulfate mineral, Cu4Al2[12|SO4]·2H2O, also known as lettsomite, very similar to halotrichite, and a member of the same group. However, it is much rarer. It forms velvety aggregates of extremely fine fibres and radial aggregates...
, brochantite
Brochantite
Brochantite is a sulfate mineral, one of a number of cupric sulfates. Its chemical formula is CuSO4·3Cu2. Formed in arid climates or in rapidly oxidizing copper sulfide deposits, it is named for its discoverer, the French geologist and mineralogist, A. J. M...
, chalcoalumite, and many other copper and uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
minerals. These specimens are now rare, as mineral collecting
Mineral collecting
Mineral collecting is the hobby of systematically collecting, identifying and displaying mineral specimens. Mineral collecting can also be a part of the profession of mineralogy and allied geologic specialties.-Motivations:...
is not permitted in the National Park.
In 2009, the mines were gated to protect bat
Bat
Bats are mammals of the order Chiroptera "hand" and pteron "wing") whose forelimbs form webbed wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums, and colugos, glide rather than fly,...
roosts, support on-going bat research, preserve historic mine resources, and promote visitor safety. The gating project was done by Mine Gates, Inc., with support from Grand Canyon National Park
Grand Canyon National Park
Grand Canyon National Park is the United States' 15th oldest national park and is located in Arizona. Within the park lies the Grand Canyon, a gorge of the Colorado River, considered to be one of the Wonders of the World. The park covers of unincorporated area in Coconino and Mohave counties.Most...
, Bat Conservational International
Bat Conservation International
Bat Conservation International is an international non-governmental organization working to conserve the world’s bats and their habitats through conservation, education and research efforts....
, and Freeport-McMoRan
Freeport-McMoRan
Freeport-McMoRan Copper & Gold Inc., often called simply Freeport, is the world's lowest-cost copper producer and one of the world's largest producers of gold...
. Details of the mine site, as well as manufacturing and installation of each bat gate are documented on the MineGates site.