Verde Heritage -- 1931: JEROME DISASTER; Rock Slide in the Open Pit Mine
MANY TONS OF WASTE ROCK FALL INTO THE STEAM SHOVEL PIT.
"An angry mountain which started 10 days ago to shake off rocks and dirt from its side down the west slope of the United Verde Copper Company steam shovel pit in Jerome, with a final roar sloughed off many thousand tons of waste into the pit last Monday night, enveloping the town in dust and making a noise which could be heard for some distance."
"The rock slide was not unexpected, and there has existed for the past two years a crack near the top of the mountain bordering the west slope of the pit. During the heavy rains last February, the rocks became loosened, and some two weeks ago started working. Since then, a part of the pit crew has been engaged in barring down the west side."
"About ten days ago, small rocks began falling at intervals, which gradually increased from day to day until Monday, when the greatest amount fell around 8 o'clock in the evening" of March 23.
"Mine officials state that production from the steam shovel pit will necessarily be curtailed until the waste is removed. However, the total production of the mine will not be curtailed, as the requisite amount will be made up from ore piles and underground workings. The same number of men are at work, but part of the crew will be engaged in removing the waste."
"The waste will be removed through underground workings, just as ore is taken out."
(Verde Copper News; Friday, March 27, 1931; page 1.)
UNITED VERDE COPPER COMPANY CURTAILMENT DUE TO ROCK SLIDE.
"Immediate shutdown of one furnace of the Clarkdale smelter of the United Verde Copper Company was announced today at the Jerome office of the company, due to curtailment of production at the steam shovel pit pending removal of waste rock which slid from the west wall into the workings last week."
"Rumors that the slide had interfered with underground working was declared entirely unfounded. W. V. DeCamp, general manager of the United Verde Copper Company, today made the following statement:"
"'The slide of waste rock, approximating several hundred thousand yards, from the walls of the pit at the United Verde Mine, which occurred last week, has materially interfered with ore production from the pit. Since the removal of this waste material from the pit will require a considerable period of time, the management has decided to discontinue immediately the operation of one of the two furnaces now operating. It is probable that in the near future the second furnace will be discontinued until such time as normal conditions are again established in the pit. Even though both furnaces are discontinued, there will be little interruption of work at Jerome, since mining of underground pillar ores will continue, as well as the construction work on No. 7 shaft, and the pit work will be pushed as rapidly as possible.'"
"'The maintenance program and the prosecution of research work at Clarkdale will require the employment of a considerable number of men.'"
"'Rumors to the effect that this slide has interfered with underground operations are entirely unfounded, and in fact, the slide is merely an aftermath of the underground movement that occurred over a year ago, combined with the fact that the steam shovel slopes were slightly steeper than is normal for such operations.'"
(Verde Copper News; Tuesday, March 31, 1931; page 1.)
UNITED VERDE SMELTER TO CLOSE MAY 21, 1931. Suspension of Operations at Clarkdale Plant Will Not Effect Mine.
"W. V. DeCamp, general manager of the United Verde Copper Company, made the following statement yesterday afternoon:"
"'The United Verde Copper Company is preparing to completely discontinue production of copper, and the one remaining furnace will be closed down approximately May 21. Operations at Jerome in connection with the removal of waste from the steam shovel pit and the establishing of new steam shovel benches will proceed as at present. Also the mining of underground ore from pillars will continue, and this ore will be stock-piled for future use.'"
"'The discontinuance of copper production, therefore, will have no effect whatsoever as to the number of men engaged in Jerome.'"
"'In Clarkdale, the nucleus of an organization will be maintained to handle repair work and continue the research program now under way.'"
"'No information is available at the present time as to when production of copper will be resumed, since the price of the metal at present is very unattractive, and there is little indication of an increase in the near future.'"
(Verde Copper News; Friday, May 8, 1931; page 1.)
The United Verde Copper Company began open pit mining during 1918. Eventually, open pit mining operations were conducted on a 24-hour, 3-shift basis.
Early on the morning of June 29, 1929, underground miners reported that ground above the 1,200 level had caved. The next day at about 4:00 a.m., workmen reported sharp noises, similar to explosions. The bottom of the pit sank about four feet and the wall cracked. About 25,000 tons of rock rubble fell into the pit. On top of the hill at the surface, there were more than twelve distinct fractures.
Open pit mining continued on the opposite side of the pit and the fractured area was surveyed and monitored. A uniform movement of the wall was recorded for 18 months, then an increased movement was noted. Rock from the fractured area began to fall at an accelerated rate until the massive wall gave way during March of 1931. An estimated 1,000,000 tons of rock fell into the pit. Removal of waste rock from the open pit continued during the "depression years," but all ore mining ceased.
The Clarkdale smelter reopened during January of 1935, and mining ore resumed. Control of the mines and smelter of the United Verde Copper Company was taken over by the Phelps Dodge Corporation on February 18, 1935.
Movement of the fractured wall of the open pit continued to be detected. About 400,000 tons of rock fell into the open pit from the wall on the southwest side of the pit during March of 1936.
(See: "A Brief History of The United Verde Open Pit, Jerome, Arizona;" by E. M. J. Alenius; Bulletin 178; 1968; The University of Arizona, Tucson.)