Silver Mines of Southwestern Idaho

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From   The principles of economic geology  By William Harvey Emmons  (page 248)

Gold-silver-adularia Veins.—The gold-silver veins of De Lamar and Silver City, Idaho, are post-Miocene deposits that were formed very near the present surface. These veins are in rhyolite, basalt, and granite. The surface at the time of deposition, as shown by Lindgren,2 was not more than 700 to 2,000 feet above the deposits mined. The gangue consists of quartz and adularia, with some chalcedony. Much of the quartz is pseudomorphous after calcite or barite. Small quantities of chlorite, epidote, barite, siderite, and calcite are present also. The ore minerals are gold, silver, argentite, proustite, pyrargyrite, polybasite, miargyrite (AgSbS2), chalcopyrite, zinc blende, galena, pyrite, and a little marcasite. Some of the rich ore was formed very near the old surface and is probably primary. The analyses of the altered rhyolite show that potash and aluminum have been removed as well as soda. The removal of both the alkalies, the presence of marcasite and chalcedony, and the extensive kaolinization of the walls are noteworthy.

Chloritic Alteration in Granitic Rock.—In many metalliferous districts three principal types of alteration are recognized— chloritic alteration in a zone extending far out from the deposits, extensive sericitization within this zone, and silication near the master fractures. Where the fractures are closely spaced the area of sericitic alteration may be hundreds of feet wide and the chloritic alteration may extend over thousands of feet. At Butte, Mont., the chloritic alteration consists chiefly of the development of chlorite and pyrite in the iron-bearing minerals, and the clouding of feldspar by incipient sericitization. Some epidote and secondary quartz also are developed. This phase appears in practically all the granite within the mineral-bearing area at Butte. Alteration of this type is attended by relatively little addition or subtraction of material. It is believed to have been brought about by gases or by waters that deposited ore and sericitized the wall rock near the ore-bearing fissures. Although less extensive, the chemical changes brought about by chloritic alteration are chemically similar to those accomplished by sericitization.

Chloritic Alteration in Lavas (Propylitic Alteration).—In many districts, particularly in certain western camps, where ore deposits were formed in lavas during Miocene and Pliocene time, the country rock is altered over wide areas. Near the surface, rooks fracture more readily than at greater depths, because they are not held down by so great a mass of overlying rocks. Hot waters and gases ascending along major fractures spread out, entering cracks and joints and mineralizing practically the entire country rock between the veins. In such a district the rocks in an area of more than a square mile may be altered, and if the district lies in a mountain range the mineralized area may be noted by an observer miles away. Experienced prospectors appreciate the significance of the alterations, which give what some designate a “kindly look” to the rock. Andesite and basalt are generally changed to a dull green; rhyolite to a paler green and locally to a chalky white.

A common type of such alteration is the propylitic phase, in which the following changes are noteworthy: Minerals containing iron, such as hornblende, pyroxene, and biotite, are altered to chlorite, epidote, and pyrite. Glassy feldspars lose their glassy habit. A glassy groundmass is recrystallized largely to feldspar and quartz, with some chlorite, epidote, and calcite. Some sericite is nearly always developed. Chemically there is a loss of sodium and generally of alkaline earths; sulphur and water are added. These changes are very common in andesites, dacites, andjmsalts. In rhyolite less chlorite and more sericite may be formed, and quartz may be added in considerable quantities by the silication of iron-bearing minerals and feldspars. In many districts the alteration increases near the veins, where less chlorite is developed and more sulphides and quartz. As in granite, three types of alteration are distinguished in some districts— chloritic alteration extending over wide areas, sericitic alteration nearer the veins, and silication of the wall rock adjoining the main fractures.

Sericitic and Propylitic Alteration Compared.—Sericitic alteration and propylitic alteration are the most common types of hydrothermal metamorphism of igneous rocks near veins that are formed at moderate and at shallow depths. They are generally attended by similar chemical changes, although the changes involved in sericitization are greater.

The propylitic and sericitic alterations at Tonopah, Nevada, have been closely studied. The Tonopah district,3 is a fault mosaic of Tertiary eruptive rocks, probably of Miocene and Pliocene age.

Mine Name County Lat Long Township Range Section
129 Rows Data exported from DRC 2.0 (c) 2009 Gary Kindel
ADDIE CONSOLIDATED OWYHEE 43.0125 -116.726111 005 S 003 W 05
ALTA PROPERTY OWYHEE 43.020278 -116.828611 005 S 004 W 05
ALTER CREEK MINING CO OWYHEE 42.897222 -116.601667 006 S 001 W 15
BANNER OWYHEE 43.009167 -116.757222 005 S 004 W 12
BAY STATE GROUP OWYHEE 42.754444 -116.930833 008 S 005 W 04
BERG OWYHEE 43.1525 -116.820556 003 S 004 W 21
BERGH-SUNNYSIDE GROUP OWYHEE 43.075278 -116.718056 004 S 003 W 17
BIG BOY PROSPECT OWYHEE 42.950556 -116.799167 005 S 004 W 34
BLACK JACK OWYHEE 43.022222 -116.757222 005 S 004 W 01
BOONEVILLE OWYHEE 43.0225 -116.755278 005 S 004 W 01
BOULDER CREEK MINES OWYHEE 42.901389 -116.703889 006 S 003 W 28
BRECCIA ZONE SILVER OCCURRENCE OWYHEE 43.058889 -116.894444 004 S 005 W 23
BROWNEY OWYHEE 43.075278 -116.718056 004 S 003 W 17
BRUNZELL OWYHEE 43.016389 -116.763611 005 S 004 W 01
CHATAUQUA OWYHEE 43.016389 -116.7525 005 S 004 W 05
CHUCKER HILL OWYHEE 43.138611 -116.395 003 S 001 E 31
CONSOLIDATED MINE & DREDGE CO OWYHEE 43.075278 -116.718056 004 S 003 W 17
CONTINENTAL QUICKSILVER OWYHEE 43.015833 -116.814167 005 S 004 W 04
COOK GROUP OWYHEE 43.013611 -116.791667 005 S 004 W 03
COPPER KING PROSPECT OWYHEE 42.708056 -116.983611 008 S 006 W 24
COSMOPOLITAN OWYHEE 43.089722 -116.709444 004 S 003 W 08
CRESCENT MINE OWYHEE 42.928889 -116.768611 006 S 004 W 02
CROWN POINT OWYHEE 43.014444 -116.743889 005 S 003 W 06
CUMBERLAND OWYHEE 43.002778 -116.686667 005 S 003 W 09
DAISY CLAIM OWYHEE 43.01 -116.840556 005 S 004 W 05
DAVIS SILVER MINES INC OWYHEE 42.959444 -116.795 005 S 004 W 27
DELAMAR SILVER MINE OWYHEE 43.013611 -116.826944 005 S 004 W 05
DELAMAR SILVER MINE AND MILL OWYHEE 42.999444 -116.696667 005 S 003 W 09
DEWEY OWYHEE 43.038333 -116.764722 004 S 004 W 36
DOUGH BOY OWYHEE 42.932778 -116.786944 006 S 004 W 03
EAST CREEK MINE OWYHEE 42.924444 -116.750833 006 S 004 W 01
EAST FORK OF REYNOLDS CREEK OWYHEE 43.084722 -116.758333 004 S 004 W 12
EDDY-CONWAY-EDDY MINING & MILLING OWYHEE 42.547222 -116.1 010 S 003 E 16
EMPIRE OWYHEE 43.005556 -116.709444 005 S 003 W 08
EMPIRE STATE OWYHEE 43.021111 -116.753333 005 S 004 W 01
ERDMAN TUNNEL OWYHEE 43.005556 -116.751667 005 S 004 W 12
GALE EXPLORATION & MINING CORP OWYHEE 43.075278 -116.718056 004 S 003 W 17
GARFIELD OWYHEE 43.021111 -116.844722 005 S 004 W 05
GOLD BUG OWYHEE 43.000833 -116.711389 005 S 003 W 08
GOLDEN CHARIOT OWYHEE 43.006944 -116.6975 005 S 003 W 09
GOLDEN CROWN MINE OWYHEE 42.853333 -116.440278 006 S 001 W 34
GOLDEN CYCLE OWYHEE 43.0175 -116.849722 005 S 004 W 06
GOLDEN GATE OWYHEE 43.075278 -116.718056 004 S 003 W 17
GOLDEN REWARD MINING & MILLING CO OWYHEE 42.818611 -116.630278 007 S 003 W 13
GOLDSIL MINES INC OWYHEE 43.075278 -116.718056 004 S 003 W 17
GRAY EAGLE CLAIM MINE OWYHEE 42.930833 -116.768333 006 S 004 W 02
HAPPY BOY OWYHEE 42.547222 -116.1 010 S 003 E 16
HENRIETTA OWYHEE 43.012778 -116.851667 005 S 004 W 06
HOME CLAIM OWYHEE 43.075278 -116.718056 004 S 003 W 17
HOMESTAKE OWYHEE 43.013333 -116.573889 005 S 002 W 04
HOOSIER LEASING OWYHEE 43.075278 -116.718056 004 S 003 W 17
HOPE CLAIMS OWYHEE 42.730278 -115.314444 008 S 010 E 17
HORNET OWYHEE 42.935 -116.787222 006 S 004 W 02
HUMBOLDT OWYHEE 43.025278 -116.756667 004 S 004 W 36
IDA BELLE OWYHEE 43.174722 -116.804722 003 S 004 W 10
IDA ELMORE OWYHEE 43.0075 -116.6975 005 S 003 W 09
INDEPENDENCE SHAFT OWYHEE 42.750556 -116.940278 008 S 005 W 04
INDIAN HOT SPRING OWYHEE 42.3375 -115.65 012 S 007 E 33
INTERSTATE GOLD MINING CO OWYHEE 43.075278 -116.718056 004 S 003 W 17
IVA GRACE OWYHEE 42.919444 -116.777778 006 S 004 W 11
JEFFERSON CLAIM OWYHEE 42.938889 -116.789444 005 S 004 W 34
JORDAN CREEK PLACER MINE OWYHEE 42.978889 -116.878056 005 S 005 W 24
LAST CHANCE PROSPECT OWYHEE 42.881389 -116.593333 006 S 002 W 20
LEE MINES OWYHEE 43.013333 -116.573889 005 S 002 W 04
LEPLEY OWYHEE 43.011667 -116.837778 005 S 004 W 05
LIBERTY OWYHEE 43.011111 -116.707222 005 S 003 W 04
LINDY OWYHEE 43.075278 -116.718056 004 S 003 W 17
MAHOGANY OWYHEE 43.002778 -116.686944 005 S 003 W 09
MAMMOTH MINE OWYHEE 42.873611 -116.720278 006 S 003 W 29
MANHATTAN OWYHEE 43.017222 -116.833333 005 S 004 W 05
MARTIN PROSPECT OWYHEE 42.944167 -116.800556 005 S 004 W 34
MAY DAY OWYHEE 42.844444 -116.340278 007 S 001 E 04
MCCALL MINE OWYHEE 42.9075 -116.6525 006 S 003 W 14
MILESTONE OWYHEE 43.029167 -116.861111 004 S 004 E 31
MINNESOTA OWYHEE 43.004444 -116.6975 005 S 003 W 09
MONARCA OWYHEE 43.143611 -116.826667 003 S 004 W 21
MORNING STAR OWYHEE 43.020556 -116.730278 005 S 003 W 06
MOTHER LODE GOLD MINING & MILLING OWYHEE 43.075278 -116.718056 004 S 003 W 17
MOUNTAIN CHIEF OWYHEE 43.013333 -116.573889 005 S 003 W 09
NELLIE ANN NO 1 OWYHEE 42.9475 -116.796389 005 S 004 W 34
NEVER SWEAT OWYHEE 42.991944 -116.710278 005 S 003 W 17
NORTH AMERICAN SILVER CORP OWYHEE 43.075278 -116.718056 004 S 003 W 17
NUGENT ANTIMONY MINE OWYHEE 43.069444 -116.728889 004 S 003 W 18
ONTARIO OWYHEE 43.018056 -116.773333 005 S 004 W 01
ORO FINO OWYHEE 43.010833 -116.698333 005 S 003 W 04
OROGRANDE GOLD INC OWYHEE 43.013333 -116.573889 005 S 002 W 04
OWYHEE SILVER MINING OWYHEE 42.998889 -116.109167 005 S 003 E 09
PAUPER OWYHEE 43.001111 -116.710833 005 S 003 W 08
PAUPER OWYHEE 43 -116.708611 005 S 003 W 08
PERSVERANCE OWYHEE 42.920556 -116.778333 006 S 004 W 11
PIXLEY BASIN MINING CO OWYHEE 42.818611 -116.630278 007 S 003 W 13
POORMAN OWYHEE 43.005556 -116.709722 005 S 003 W 08
POTOSI OWYHEE 43.014444 -116.732222 005 S 003 W 06
PYRAMID PLACER MINE OWYHEE 42.986389 -116.086111 005 S 003 E 15
QUEEN OF THE MOUNTAINS OWYHEE 42.750556 -116.930278 008 S 005 W 09
RICH GULCH MINE OWYHEE 43.011111 -116.778056 005 S 004 W 02
RISING STAR OWYHEE 42.919722 -116.776667 006 S 004 W 11
RUBY CITY MINING CO OWYHEE 43.075278 -116.718056 004 S 003 W 17
RUTH OWYHEE 43.0175 -116.715556 005 S 003 W 05
SAN JUAN OWYHEE 43.004444 -116.700278 005 S 003 W 09
SIERRA NEVADA OWYHEE 43.015278 -116.751389 005 S 004 W 01
SILVER BURG MINE OWYHEE 43.161389 -116.835833 003 S 004 W 17
SILVER CITY GOLD MINES OWYHEE 43.075278 -116.718056 004 S 003 W 17
SILVER CORD OWYHEE 43.005 -116.709444 005 S 003 W 08
SILVER QUEEN OWYHEE 42.927222 -116.775556 006 S 004 W 02
SILVER VAULT PROPERTY OWYHEE 43.005833 -116.840278 005 S 004 W 08
SINKER TUNNEL OWYHEE 43.019722 -116.680833 005 S 003 W 03
SLACKS MOUNTAIN PROSPECT OWYHEE 43.075 -116.738056 004 S 003 W 18
SOMMERCAMP PLACER OWYHEE 43.009722 -116.838056 005 S 004 W 05
SOUTH CHARIOT OWYHEE 43.003333 -116.697222 005 S 003 W 09
SOUTH MOUNTAIN MINE OWYHEE 42.741667 -116.910278 008 S 005 W 10
STANDARD OWYHEE 42.740556 -116.904167 008 S 005 W 10
STORMY HILL OWYHEE 43.004722 -116.706667 005 S 003 W 09
SUMMIT OWYHEE 43.017778 -116.767778 005 S 004 W 02
SUNNYSIDE MINE OWYHEE 43.016389 -116.604722 005 S 002 W 05
TAIMAGE RAWHIDE MINE CO OWYHEE 42.818611 -116.630278 007 S 003 W 13
TANGO OWYHEE 43.075278 -116.718056 004 S 003 W 17
TENNESSE MOUNTAIN PROSPECTS OWYHEE 43.050556 -116.785 004 S 004 W 26
TENNESSEE MOUNTAIN PROSPECTS OWYHEE 43.049722 -116.780833 004 S 004 W 26
TIP TOP OWYHEE 43.0175 -116.773056 005 S 004 W 01
TRADE DOLLAR OWYHEE 43.009167 -116.743056 005 S 003 W 07
TREASURE VAULT OWYHEE 42.930278 -116.778333 006 S 004 W 02
TROOK OWYHEE 43.013333 -116.716111 005 S 003 W 05
TUNNEL GROUP OWYHEE 42.750278 -116.922778 008 S 005 W 04
TWIN PEAK PROSPECTS OWYHEE 43.086667 -116.856667 004 S 004 W 07
VENUS CLAIM OWYHEE 43.001667 -116.761667 005 S 004 W 12
VILLAGE BLACKSMITH OWYHEE 43.075278 -116.718056 004 S 003 W 17
WHITE HORSE OWYHEE 42.93 -116.835833 006 S 004 W 05
YMIR CONSOLIDATED MINING CO OWYHEE 43.075278 -116.718056 004 S 003 W 17

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