Professional Paper 144 Butler & Burbank
The Arcadian lode (pl. 42) was first opened by the Arcadian and Concord companies, which produced a small amount of copper. The most extensive developments were made by the Arcadian Copper Co. within a period of a few years, beginning about 1898. The lode was opened for about 8,000 feet along the strike by five shafts. North and south of this developed area are shallow shafts. The principal shafts from north to south are No 4, opened to the sixth level; No. 3, to the seventh level; No. 2, to the eighth level; No. 1, to the fifth level; and shaft A, to the ninth level. The most extensive stoping was done from No. 2 shaft, near the center of the developed area, and from shaft A, at the south end of the developed area. From 1899 to 1902 the Arcadian Copper Co. produced 2,950,000 pounds of copper. There is no available record of the grade of the ore, but it was not sufficiently high to justify continued mining of the lode.
The Arcadian lode is a few hundred feet above No. 8 conglomerate and is believed to be the northward extension of the Isle Royale ("Grand Portage") lode. It was said to average about 13 feet in thickness. The material on the dump indicates that the lode is well oxidized, and that, like the Isle Royale, it is strongly fragmental. The mineralization appears to be in general similar to that of the Isle Royale, though there is considerable feldspar in the Arcadian lode and little of the sericite that is locally abundant in the Isle Royale lode.
NEW ARCADIAN LODE
The New Arcadian lode is a short distance above No. 8 conglomerate and below the Arcadian lode. It has been developed by the Arcadian Consolidated Copper Co. through the New Arcadian and New Baltic shafts. From the New Arcadian shaft the lode has been opened along the strike for a minimum distance of about 2,500 feet on the 600-foot level, and the shaft goes down to the 1,850-foot level. From the New Baltic shaft it has been opened for about 1,500 feet-along the strike and down to the 1,250-foot level; the most work has been done on the 950-foot, 1,100foot, and 1,250-foot levels.
The New Arcadian lode is in general of the fragmental type, but stretches of fragmental rock alternate with stretches of cellular rock. The fragmental areas show encouraging mineralization, which is mainly of the quartz-pumpellyite-epidote type with some fairly coarse copper. Areas of cellular amygdaloid in this, as in other lodes, are characteristically poor.
No heavy faulting of the lode has been recognized, but there are some faults of small throw that offset the lode and have caused some difficulty in following it. To the present time (1925) there has been only a little test stoping and no production on a commercial scale. In 1915, according to the annual report of the company, 3,845 tons of rock yielded 79,209 pounds of copper, or an average of 20.62 pounds to the ton. In 1916, 1,391 tons of rock yielded 32,307 pounds, or 23.23 pounds to the ton. In 1917, 4,900 tons of rock yielded 53,278 pounds, or 10.87 pounds to the ton. The average for the three years was 16.3 pounds to the ton.
PRODUCTION AND CHARACTER
The main output from the Winona lode (pl. 42) has been derived from the Winona mine, which includes the King Philip mine. The lode was opened by old Indian pits and therefore discovered early. Operations by white men began about 1864, and a little copper was produced in succeeding years. In the earlier part of the productive period the recovery was not very high, because much of the copper is in rather fine particles. From 1902 to 1907 about 3,350,000 pounds of copper was produced. The mine was then idle till 1911, when the company was reorganized as the Winona Copper Co., and it was then active till 1920, when operations were suspended except for a little development work. Its total recorded production, from 1902 to 1920 is 1,262,678 tons of rock, yielding 17,684,234 pounds of copper - an average of 14 pounds to the ton.
The Winona lode is about 400 feet above No. 8 conglomerate, at the general horizon of the Isle Royale lode.
On the Winona property the Winona lode is developed by six shafts - from north to south Nos. 1 to 4 Winona and Nos. 1 and 2 King Philip. Development has been carried for about 9,000 feet along the lode.
The northern part of the developed portion of the lode crops out just at the base of a prominent bluff. On this outcrop the Indians dug shallow pits, and it was eventually opened by the northern Winona shafts. The southern part of the developed portion of the lode, which is opened by the southern Winona shafts and the King Philip shafts, was covered by glacial drift.
The writers did not examine the mine. The following description is made up from the mine maps, from examination of the dump, and from descriptions by Messrs. T. S. Woods and R. R. Seeber.
The lode, which is of the fragmental type and fairly well oxidized, appears to be very irregular, changing from thick to thin within short distances. There is a persistent "slide" or gouge zone a few feet above the lode - Mr. Seeber says about 14 feet. In places the lode extends to this "slide."
The mineralization was of the same general type as that of the other lodes. Pumpellyite, quartz, epidote, and calcite are plentiful. Prehnite, laumontite, and probably other minerals are present. The copper is associated with quartz and pumpellyite.
As indicated by present developments, the ore lies in a flat southward-dipping shoot (see pl. 42) that crops out near Winona No. 2 shaft. The northern Winona shafts seem to pass through the shoot, but in the King Philip shafts it is several hundred feet below the surface. The ore-bearing ground is apparently made up of a series of small nearly parallel shoots, interspersed with poor streaks. Even the smaller shoots contain areas in which the lode is thick and relatively high in copper and areas in which the lode is thin and poor. Where the lode extends to the hanging-wall slip it is said to be thick and rich.
The Winona lode in many ways resembles the Isle Royale lode with which it is commonly correlated. So far as learned, however, it does not show the tendency for the ore to form near the footwall, which is so persistent and unusual a feature of the Isle Royale lode.
The Winona lode was opened at the Wyandot mine by a shaft to the 1,000-foot level, from which short drifts were run. The lode was reported as carrying some copper, but operations in this mine were soon discontinued.
ELM RIVER MINE
The Elm River Copper Co. opened a lode at the general horizon of the Winona by a shaft to the 500-foot level, where drifts were extended for about 1,000 feet. The lode was also opened on the first level for a few hundred feet. The results were apparently not very encouraging. At No. 6 shaft the lode was entered by a crosscut at a depth of about 250 feet and was followed for about 700 feet.
The Cherokee Copper Co. opened a lode that is farther from No. 8 conglomerate and possibly stratigraphically higher than the Winona lode. A shaft was sunk to the fourth level and short drifts carried on each level. It was reported that some stretches of commercial ground were opened. There is a fault south of the shaft (see pl. 12) that displaces the rocks on the south about 500 feet to the east.
WYANDOT NO. 8 LODE
The Wyandot Copper Co. opened a lode in a crosscut from the 700-foot level, No. 11 shaft, about 1,100 feet horizontally (950 feet stratigraphically) below the hanging wall of No. 8 conglomerate. The lode was opened on this level and by a winze to the 800, 900, and 1,000 foot levels, on each of which drifts were carried. The lode is fragmental in character, and the results were reported as somewhat encouraging. A test shipment of 1,605 tons of rock made in 1917 yielded 12.54 pounds of copper to the ton.
EVERGREEN AND SUCCEEDING LODES
All the mines on the Evergreen and succeeding lodes were idle at the time the region was examined, and only very meager observations underground were made at the Mass and Adventure mines.
From the Lake mine at the north to the Victoria mine at the south there have been rather extensive developments on a series of lodes whose base is about 400 to 500 feet above No. 8 conglomerate and which extends through a thickness of about 500 feet of flows. This series is at the general horizon of the Winona and Isle Royale beds, to the north, and of the Forest ("Victoria") lode, to the south. The correlation of individual flows from one development to another is probably somewhat uncertain, but in each of the openings in the Lake, South Lake, Adventure, Mass, and Michigan mines there are several lodes that carry sufficient copper to have encouraged extensive development, and a substantial amount of copper has been produced from the series as a whole.
From higher to lower horizons the lodes are the Knowlton, Merchant, Mass, North Butler, Butler, South Butler, Ogima, and Evergreen, with other amygdaloids present in places. (See pls. 43-46.) The position of these lodes is shown in Plate 13. The lodes that have been most developed and most productive are the Butler, Evergreen, and Knowlton. The Butler lode has yielded the largest amount, but the Evergreen and Knowlton lodes have made a considerable output.
The records of production from the several lodes of the series have not usually been kept separate by the mining companies, but the total for the series is essentially the production of the companies mentioned below, with the exception of the production from the Minesota fissure and the Calico lode by mines that have become a part of the present Mohawk Mining Co. (Michigan mine) and from the Lake lode by the Lake Mining Co., which is not here included with the group.
Production from the Evergreen and succeeding lodes to the end of 1925
|Mine||Period||Rock treated (tons)||Copper produced (pounds)|
a Does not include production from the Lake lode.
b Estimated; does not include production from the Minesota fissure and Calico lode.
CHARACTER OF FLOWS
The flows of the Evergreen and succeeding lodes are intermediate in composition, falling toward the andesite end of the basaltic series. Texturally they are chiefly melaphyres and glomeroporphyrites, but ophitic texture occurs in some of the thicker flows.
Next to the general tilting of the beds and the Keweenaw fault the largest structural feature affecting this series of beds is the pronounced anticline with its crest at Mass. This fold extends southward nearly to Flintsteel River and northward to the Lake mine. Like the Baltic anticline, it does not show a gradual change in strike around the fold but a very sharp change at Mass City of about 35°.
The Lake mine syncline extends into this region, and this series of beds are involved in that fold, but the correlation of the individual beds in the Lake mine basin with the normally dipping beds to the north is somewhat uncertain, and the lodes have therefore been considered separately. There are many fissures and faults with small throw on the Mass anticline, as is usual where the rocks have been folded to that extent. The opportunity for observing these fissures has been too meager to warrant any generalizations regarding them. It may be noted, however, that many of them are probably tension fissures resulting from the folding, though some are essentially strike fissures that dip in an opposite direction to the lode. All the fissures noted are mineralized and were evidently formed before the period of mineralization, though there has been movement on some of them since mineralization.
Wherever seen the amygdaloids of this series of flows are fragmental to some degree. Very commonly the fragmental material is rather coarse and trappy. Like all other fragmental amygdaloids these differ greatly in different places, but characteristically areas in which the lode is moderately thick and fragmental alternate with areas in which it is thin and cellular or trappy and fragmental. The relative extent of these areas varies from place to place.
Some of the lodes, especially parts of the Evergreen lode opened in the Mass mine, show locally a distinct tendency to pass into amygdaloid of the coalescing type, though this tendency was not seen to persist over very large areas.
The result of mineralization in all the lodes of the series is similar. The abundant minerals are quartz, feldspar, pumpellyite, chlorite, calcite, and epidote. Red feldspar is usually abundant in all the lodes. The less abundant minerals are prehnite, datolite, and laumontite. Zeolites other than laumontite were not noted though possibly present. Anhydrite was found on the dump at the Mass mine, but this mineral seems to be relatively rare in these as in other lodes.
Copper in small and large masses is irregularly distributed through the lode. In the Evergreen lode, in the Mass mine at least, much of the copper is present in masses - in fact a rather large percentage of the copper in all the lodes is coarse.
The quartz-pumpellyite rock is the characteristic product of rock alteration associated with the copper, though there has been much replacement of rock by red feldspar and less by chlorite and epidote.
RELATION OF MINERALIZATION TO CHARACTER OF LODE
A close relation between character of lode and mineralization is evident wherever the lodes have been examined. Rich ground is wholly confined to fragmental parts of the lode, and the areas of good ground usually coincide with areas in which the lode is also relatively thick. The thin, cellular, and trappy parts of the lode are consistently poor. There is apparently some tendency for the favorable rock to form belts or "shoots," but observation in the mines has been too scanty to make this certain.
The Butler lode (pl. 45) has been the most productive of the lodes of this series and has been most extensively developed in the Mass mine, where it has been opened for about 5,000 feet along the strike and rather extensively to the thirteenth level. Large areas have been stoped in the ground adjacent to shaft C. Near shaft B and, more especially, near shaft A the stoping has not been as continuous, and presumably the ground is less regularly mineralized.
Lithologic character. - Where examined, as it has been over small areas only, the lode is generally fragmental but largely of rather coarse trappy character. As in most other fragmental lodes, areas of definitely fragmental rock are interspersed with areas of thin trappy or cellular rock. Mr. E. W. Walker, the superintendent, states that in places the lode was unusually wide and was mineralized near the footwall and hanging wall but barren in the middle. In such places two stopes were carried.
Structure. - The main structural feature of the lode in this mine is a series of mineralized fissures. Locally these may show slight displacement, but they rarely offset the lode as much as its width. A "crossing" near shaft A is said to displace the lode along a brecciated zone. No mapping of the fissures has been carried over the area, but there is one series striking northeast and one northwest. There are also fissures striking approximately with the lode, some of which dip with the lode and others across the lode at a high angle. All the fissures contain essentially the same minerals as the lode and were evidently formed before the mineralization, though there has been movement on some of them since mineralization. According to Mr. Walker, no close relation between fissuring and mineralization of the lode has been recognized, though the fissures have evidently rendered the lode more permeable.
Mineralization. - The most abundant minerals of the lode are quartz, calcite, pumpellyite, epidote, and feldspar. Datolite is not uncommon but apparently not abundant. The pumpellyite type of bleaching was the characteristic alteration associated with the deposition of copper. The fine copper of the stamp rock is said to be more evenly distributed in this lode than in the Evergreen lode. That there is considerable coarse copper, however, is indicated by the fact that mass copper constituted about 26 per cent of the total mine production. In the present stage of development, no definite trend of ore shoots has been recognized on a large scale. Minor shoots of good and poor ground are recognized.
Yield. - During the late years of mining by the Mass Consolidated Mining Co. the yield was about half a ton of stamp rock per square foot of lode. As about 50 per cent of the rock was discarded underground, about a ton of rock per square foot of lode was broken, or an average thickness of around 12 feet. The rock milled yielded 15 to 17 pounds of copper to the ton.
In the Adventure mine the Butler lode has been opened for about 2,500 feet along the strike and down to the eighth level, but only relatively small areas have been stoped. Where seen in the upper levels fragmental rock seems to form a relatively small proportion of the lode, and the areas between the fragmental portions are "tight" and poor. The mineralization was similar to that in the Mass mine. No records of the grade of rock or production are available.
SOUTH LAKE MINE
The Butler lode has been opened to a small extent in the South Lake mine from the surface to the 600-foot level. It is stated in the company reports that the openings made on the lode before operations were suspended were encouraging and that it gave the most promise of all the lodes in the mine. Rock milled in 1918 amounted to 7,694 tons and averaged 28 pounds of copper to the ton. It is not stated to what extent this rock was selected.
Development work on the Butler lode was done in the Lake mine from 1917 to 1919 through a crosscut on the 600-foot level of the Knowlton shaft. The lode was opened for about 1,400 feet along the strike and was reported to contain stretches of fair copper ground. The lode had been earlier opened by the No. 1 and No. 2 Butler shafts from the surface to the third level and for about 1,000 feet along the strike. Some stoping was done on the first and second levels, but no record of the results is available.
NORTH LAKE MINE
The North Lake Co.'s report for 1918 states that the Butler lode was cut in the 800-foot crosscut and followed by a drift for 30 feet. It was said to contain an encouraging amount of copper.
In the Mass mine the Evergreen lode (pl. 46) has been opened for about 3,500 feet along the strike. It has been rather extensively opened down to the eleventh level from shaft B and to a lesser depth and lateral extent from shaft A. There was no good opportunity to examine this lode in its best-mineralized portions. It is evidently fragmental, though not so highly fragmental as the Butler lode, and in places is coalescing. The fragmental part of the lode is of the rather coarse trappy type. Its mineralization was similar to that of the other lodes of the series. Quartz, calcite, pumpellyite, epidote, and feldspar are the common minerals. Like the adjoining lodes, this lode is cut in the Mass mine by numerous fissures. All are mineralized, and some contain considerable copper. The copper is coarser than in the Butler lode, yielding a larger proportion of mass - in fact, stamp rock is relatively unimportant. The copper is said by Mr. Walker to show a slight tendency to occur in shoots with a southwesterly pitch.
The production from this lode, in recent years at least, has been much less than that from the Butler lode.
In the Adventure mine the Evergreen lode has been opened for a few hundred feet on the adit level and to a slight extent on the sixth level. Little stoping has been done in this mine. The lode where seen in the adit level is fragmental but relatively thin. It contained copper rather persistently for a foot or so near the hanging wall.
SOUTH LAKE MINE
The Evergreen lode was cut in the South Lake workings, but no record of its character as there shown has been found.
In the Lake mine the Evergreen lode was cut on the 600-foot level from the Knowlton shaft and opened for about 700 feet along the strike. The report of the company for 1919 states that the lode as opened is very encouraging and is considered the best of the series as opened in the Lake mine. A stope over 200 feet long was started. Small test shipments, roughly picked at the surface, yielded from 18 to 34 pounds to the ton.
NORTH LAKE MINE
The Evergreen horizon was reached in the North Lake workings, but no description of the character of the lode is available.
The Knowlton lode (pl. 43) has been most extensively opened in the Mass, Adventure, and Lake mines. It was seen in only a few places in the Mass mine, where it is of the fragmental type. As judged from the material on the dumps, it is fragmental in the other places where it has been opened.
In the Mass mine the Knowlton lode has been most extensively opened from shaft C. On the third level a drift has been carried on the lode for about 2,000 feet. The lode has been largely stoped for 200 to 300 feet each side of shaft C to the eighth level. In shaft B the lode has been opened on the fourth, seventh, tenth, and eleventh levels, but little ground has been stoped. From shaft A it has been opened on the tenth level only. Near shaft C, according to Mr. Walker, it was of good grade.
The main operations of the Adventure mine were on the Knowlton lode. In Nos. 1, 2, and 3 shafts the lode was opened for about 2,000 feet along the strike, and in No. 3 shaft it was opened to the thirteenth level. Only a relatively small proportion of the ground opened was stoped. The largest areas stoped were near No. 2 shaft to the tenth level and midway between Nos. 3 and 4 shafts on levels 7 to 10.
No. 4 shaft was supposed to be located on the Knowlton lode, but later a lode was found about 60 feet from the hanging wall of the one on which the shaft was sunk, and it was thought that this might be the Knowlton. The lode as opened in the Adventure mine has averaged rather low in copper. Prior to 1906, according to the company's report of 1907, all rock stamped averaged 12.29 pounds to the ton; in the first half of 1907 it fell to 8.7 pounds, but it improved during the second half of that year, when the mine was closed. The mine was operated for a short time in 1916-17 but was soon closed again.
The Knowlton lode has been opened at the Lake mine for about 1,200 feet along the strike and as deep as the sixth level in the main Knowlton shaft. Stoping has been done near this shaft from the first to the sixth levels. Some areas of fair ground were said to have been opened.
A lode that is locally known as the Butler lode but appears to be higher, possibly at the Knowlton horizon, has been opened by shaft E of the Michigan mine to the eighth level and for a maximum distance along the strike of about 1,400 feet. The most extensive stoping has been done in what appears to be a westward-pitching shoot that crosses the shaft below the fifth level. (See pl. 43.) As indicated by material on the dump the lode is fragmental, and the character of mineralization is similar to that at other places where the lode has been opened.
The Ogima lode (pl. 44) has been opened to a slight extent in shafts C and B of the Mass mine and in the Adventure mine. It contains patches of fragmental rock, and some of these are fairly well mineralized. The openings on the whole have apparently not been encouraging.
There has been slight development of the Merchant and North Butler lodes in the Mass and Adventure mines and of a lode in the foot of the Evergreen at the Lake mine. These lodes are somewhat fragmental and in places carry copper, but as yet they have offered little encouragement to extensive development.
FOREST ("VICTORIA") LODE
The statements regarding the Forest lode (pl. 47) are based on a brief visit to the Victoria mine in August, 1923, on the mine maps and records, and on statements by the late George Hooper, superintendent during the later operations, and by Charles Hooper.
The Victoria mine, on the Forest lode west of Ontonagon River, is the westernmost mine on the main range that has made a notable production. It was also one of the earliest producers in that part of the district.
Production of Forest lode in Victoria mine to end of 1923
|Period||Rock treated (tons)||Copper produced (pounds)|
The Forest lode is one of the series a short distance above No. 8 conglomerate, but with which one, if any, of those developed to the east it is to be correlated is not certain, and it is therefore considered separately. It is low in the series and probably near the Evergreen horizon. This lode has been slightly prospected for several miles to the south on the Tremont-Devon, Cass, and other properties but not extensively developed.
CHARACTER OF AMYGDALOID
Where seen in the Victoria mine the lode shows alternations of areas of rather thin cellular to coalescing amygdaloid with smaller areas of fragmental rock. The areas of fragmental rock seemed to bulge rather deeply into the underlying material, but Mr. Hooper stated that there were bulges of this character into the hanging wall also. The fragmental parts of the lode are 50 feet thick in places. The thicker masses of fragmental rock are irregularly distributed in the developed area, though they show some tendency to form shoots.
Quartz, pumpellyite, epidote, and calcite are the most abundant minerals associated with the copper. Prehnite is fairly abundant. The rock alteration is mainly of the quartz-pumpellyite type.
Much of the copper occurs as relatively large masses. Mr. Hooper stated that in the later operation mass copper had run as much as 50 per cent of the total production and that the stamp rock was of low grade, carrying less than 10 pounds of copper to the ton. The thick bulges of fragmental rock are by far the richest portions of the mine, though Mr. Hooper stated that such rich areas have not yielded a very large proportion of the total output. The richness of the ground seems to show a close relation to the degree to which the lode is fragmental.
EXTENT OF DEVELOPMENT
The lode has been opened in the Victoria mine for about 3,800 feet along the strike and to the twenty-eighth level. The area in which extensive stoping has been done is considerably less, as can be seen by reference to Plate 47.
Some work was done in the early days on the Tremont-Devon property, west of the Victoria, and more recently diamond drilling has been done in order to locate the Forest amygdaloid. An amygdaloid that was thought to be the Forest was encountered and was reported to contain some copper.
The Lake lode (pl. 48) was located by diamond drilling in 1907. Development began in 1908, and the first production was made in 1909. From 1909 to 1918, when production was suspended, the Lake lode had yielded 7,326,227 pounds of copper. The yield ranged from about 16.0 to 26.5 pounds per ton of ore milled and averaged about 23 pounds. The rock was sorted to a varying degree. The company's report for 1918 states that "All new stopes opened in the Lake shaft showed a steadily decreasing copper content of rock. * * * In the newer stopes 5 or 6 tons had to be discarded for every ton shipped."
The Lake lode was discovered and first opened near the Keweenaw fault. Developments on the lode in the Lake and South Lake mines show that this portion of the lode is on the north end of a synclinal basin pitching southwest.
The openings on the lode were not accessible when the writers visited the region, and the statements concerning the lode are taken largely from the records and reports of the Lake and South Lake companies and from descriptions by Mr. C. J. McKie, manager of the Lake mine when operations on the lode were suspended.
The general structure of the area is that of a broad syncline lying between the northward-dipping series of the Evergreen Bluff, to the north, and the Keweenaw fault, to the south. The main workings of the Lake mine are around the north end of this basin, and those of the South Lake mine are on the north side of the basin, where the beds dip to the northwest and southeast from the axis of an anticline that strikes about with the general trend of the range.
In the present stage of development there is possibly some uncertainty as to the exact correlation of the Lake lode with the lodes north of the anticline, which have the normal northerly dip of the range. It seems clear, however, that the Lake lode is one of the series of lodes above No. 8 conglomerate, and probably it is near the Evergreen lode of that series. A lode which may or may not be the Lake lode has been opened at the Algomah mine, west of the Lake mine, on the south side of the Lake mine basin, at the general horizon of the Lake lode.
The Lake lode is distinctly of the fragmental type, and, like the Evergreen and most of the succeeding lodes, where they have been opened, it shows great variation in thickness from place to place. In some places it is apparently thick and fragmental; in others the amygdaloid has nearly disappeared.
The lode has been developed in the Lake mine for a distance of about 3,500 feet along the strike and down to the eleventh level. Some copper is said to be present throughout these openings, but the copper content was highest for a distance of 500 to 600 feet north and south of the main shaft, where 25 to 30 per cent of the rock has been stoped. It is reported that some copper was found in the drift on the Lake lode in the South Lake mine, but no stoping was done.
The fragmental amygdaloid of the Lake lode was brown and well oxidized. The principal minerals associated with the copper are quartz, pumpellyite, and calcite, which are accompanied by some epidote and a little red feldspar. The alteration of the lode rock was typically of the quartz-pumpellyite type.
Operations on the Algomah lode began in 1910, but the only production has consisted of test shipments. A shipment of 74,560 pounds of ore made in 1914 yielded 18 per cent of copper, according to the company's report for that year.
The shaft on the Algomah lode is on the south side of the Lake mine basin, at the general horizon of the Lake lode and only 60 feet from the Keweenaw fault. Whether or not this lode is the same as the Lake lode has not yet been determined. Near the surface the lode dips 60° N. The shaft was not accessible at the time of the writers' visit to the district. In a short level about 30 feet below the collar of the shaft the lode is mainly cellular, with small areas of fragmental amygdaloid. The rock showed the pumpellyite rock alteration characteristic of many of the lodes in this part of the district. The company's reports, however, state that little native metal was found but that the copper was nearly all combined as black oxide, melaconite, green carbonate, malachite, and silicate. The ore seen on the dump corroborates this statement.
The lode has been developed for about 2,000 feet along the strike on the first level. About 1,000 feet north of the shaft the drift on the amygdaloid entered the Keweenaw fault, which was followed for some distance. The shaft was sunk to a depth of 558 feet, and a crosscut was driven north from the second level for about 950 feet to explore for other lodes.
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