Description
Robert Metcalf
Commodities
PrimaryCopper, Kaolin
SecondaryGold, Silver
Commodity typeB
Deposit
Deposit sizeM
WorkingsSurface/Underground
Orebody formIRREGULAR
Ore controlFunnel-Shaped Mass Occurs Between 2 Large Porphyry Dikes; Irregular And Tabular Deposits Of Very Rich Oxidized Ores Along Contact Between Limestone And Porphyry
Materials
Ore mineralsChalcocite, Chalcopyrite, Cuprite, Kaolin, Kaolinite, Malachite, Pyrite, Sphalerite
GangueEpidote, Garnet, Hornblende, Limonite, Magnetite, Tremolite
Geology
Host rockLimestone · Longfellow Limestone;Morenci Shale
Associated rockQuartz Monzonite · Coronado Quartzite;Morenci Granite Porphyry
StructureOre Bodies In Region Tend To Follow Porphyry Contacts, Well-Defined Fault With Strike Of N65w And Upthrow On South Side Of 80 To 100 Ft; 3 Main Porphyry Dikes That Trend Ene, Widen Considerably With Depth (From 20 Ft Wide On Surface To 90 Ft Wide At Depth), And Send Out Horizontal Sheets In The Lower Part Of The Longfellow Limestone
Tectonic settingPrecipitous Gully Terrain; Coronado Quartzite Forms Cliffs 200 Ft High And Lower Slopes Of Modoc Mountain Were Practically Inaccessible Before Morenci Open Pit Was Developed
AlterationSericitized Porphyry. Morenci Shale Shows Hardening And Introduction Of Epidote; Limestone Contains Seams Of Magnetite Intergrown With Pyrite, Chalcopyrite, And Prisms Of Pyroxene; Substantial Surface Oxidation To Limonite And Kaolin
Economic & production
Development statusProducer
First production1882
Last production1932
Discovery year1872
Identification
Deposit ID10048281
MRDS IDM800406
Alternate namesPart Ofarizona Copper Co Group, Longfellow Incline
RegionNA
Data scoreB
Coordinates33.08454, -109.35871
References
ABGMT-USBM FILE DATA.USBM FILES, LONGFELLOW INCLINE.ABGMT CLIPPING FILE, LONGFELLOW EXTENSION COPPER CO, ARIZONA COPPER CO LTD.BLM DISTRICT SHEET 840 AND 839.USGS PP 43, P. 233-239.STEVENS, H.J., 1911, THE COPPER HANDBOOK, VOL X, PAGES 356-357, ARIZONA COPPER CO LTD.WEED, W.H., 1918, THE MINES HANDBOOK, VOL. X111, PAGE 470, ARIZONA COPPER CO LTD.TENNEY, JAMES B., HISTORY OF MINING IN ARIZONA, VOL. 1, P. 97.BENNETT, 1975, GEOLOGY AND ORIGIN OF THE BRECCIAS IN THE MORENCI-METCALF DISTRICT, GREENLEE CO., AZ: MS THESIS UNIV OF AZ.PHILLIPS, K.A., 1987, ARIZONA INDUSTRIAL MINERALS: ARIZONA DEPARTMENT OF MINES AND MINERAL RESOURCES MINERAL REPORT 4, 185 P.CIMRI