Pacific Division Meeting Field Trip Guide for the Blue Ledge Mine

Pacific Division Meeting

Field Trip Guide for the Blue Ledge Mine, Siskiyou County, California

Field Trip Leaders: Bill Elliott (Dept. of Geology), Kathleen Page (Dept. of Biology), and Steve Petrovic (Dept. of Chemistry), Southern Oregon University

Field trip guide written by William S. Elliott, Jr.

Southern Oregon University

June 12, 2005

Medford Jacksonville

Phoenix Applegate

Ruch Talent 99 Pompadour Bluff Ashland

K L A M Mt. A Ashland T H 5 Applegate o

Reservoir W 123 00’ OREGON o

N 42 00’ M CALIFORNIA Joe Elliott Creek Creek O U BLUE LEDGE MINE Condrey N Mountain T A I N S

96 N

Yreka 0 10 20 km

Figure 1: Index map to the travel log and location of the Blue Ledge Mine in Siskiyou County, California.

2 Travel Log Below is a brief travel log that summarizes the geological and historical aspects of the route to the Blue Ledge Mine. Refer to Figure 1 for the location of the communities and routes described in the passages and Figure 2 for a regional geologic map of southwestern Oregon and northern California. Historical information is partially derived from the Southern Oregon Historical Society’s Historic Discovery Drives. The mileages provided are cumulative.

0 miles 0 km Leave the parking lot in front of the Science Building at Southern Oregon University. Travel west on Ashland Street to Mountain Avenue, then turn right heading north. At the intersection with Siskiyou Boulevard (Highway 99), turn left and head northwest toward Ashland. A few blocks beyond downtown Ashland, there are views of the southern part of the Bear Creek Valley. The Bear Creek Valley marks the transition between two distinct geological provinces, the Klamath Mountains to the west and the Western Cascades to the east. The Bear Creek Valley is the result of differential weathering and erosion of the sandstones and mudstones of the Cretaceous Hornbrook Formation. The high relief area to the west is part of the Klamath Mountains and consists of numerous Late Paleozoic and Mesozoic metamorphic terranes with intrusive igneous rocks, such as the Jurassic granodiorite of the Mt. Ashland pluton. The high relief area to the east is part of the Western Cascades, an Oligocene to Miocene volcanic arc predating the High Cascades of southern Oregon. At the far end of town near the railroad trestle, there are several exposures of mudstone of the Cretaceous Hornbrook Formation along Highway 99.

3.2 miles 5.1 km Near the intersection of Highway 99 with Valley View Road, there are several stream terraces to the east of Bear Creek. Approximately 0.5 miles north of this intersection, there are several exposures of metasedimentary rocks of the Triassic to Jurassic Hayfork terrane of the Klamath Mountains in several roadcuts along Highway 99. Beyond these exposures, Highway 99 continues on alluvium derived from Bear Creek.

6.4 miles 10.2 km Community of Talent. Highway 99 continues to parallel Interstate-5 and Bear Creek on Quaternary alluvium deposits. Jacob Wagner was one of the first European settlers to claim property in the vicinity of Talent in 1852 and built a house along present day Wagner Creek. During the summer of 1853, Captain Alden erected a fort on Wagner’s property to protect early settlers from the American Indians. From August 1853 to January 1854, three notable wagon trains arrived and the settlement took hold. The city is named for another settler who came later, Aaron P. Talent. Talent was a carpenter and farmer, and he established one of the first retail businesses, a general store, in the community. Although several previous names were proposed for the town at one time, such as “Vernon” or “Wagner”, the town was named for A. P. Talent. Talent is also the location of the first school house in Jackson County, built in the summer

3 N

ASHLAND

Blue Ledge Mine

Figure 2: Simplified geologic map of the Klamath Mountains in southwestern Oregon and northern California. The Blue Ledge Mine is located within the Condrey Mountain terrane. This figure is slightly modified from Mortimer & Coleman (1984).

4 of 1854 on the banks of Bear Creek about a quarter mile northeast of Fort Wagner. The railroad made its way through Talent in 1884.

9.1 miles 14.6 km Community of Phoenix. Continue on Highway 99 north on alluvium of Bear Creek to South Stage Road. The original town site of Phoenix was settled by the Clover family in the early 1850s. Phoenix, along with Talent and Ashland, were along the main wagon trail through the Bear Creek Valley.

10.4 miles 16.6 km Intersection of Highway 99 and South Stage Road. Turn left onto South Stage Road, which will skirt the southern edge of Medford. South Stage road continues on alluvium of the Bear Creek Valley and transitions to low rolling hills underlain by sandstones of the Cretaceous Hornbrook Formation. Exposures of the sandstones of the Hornbrook Formation may be seen in several exposures along South Stage Road to Jacksonville. In the early settlement of the valley, several skirmishes occurred between settlers and the natives. These incidents are referred to collectively as the “Rogue River War”, which lasted five years from the first successful settlement on Wagner Creek to the last battle in October 1855. The extraction of natural resources and the consumption of timber by the miners and settlers resulted in the decimation of fish habitat, primarily from hydraulic mining practices. After the war ended in June of 1856, the remaining native peoples were moved to a reservation near Table Rocks, two buttes north of Medford capped by a Miocene lava flow of the High Cascades. Fort Lane was built near Lower Table Rock and the Rogue River to protect the natives on the reservation. Unfortunately, local hostilities did not end and the Table Rock Reservation was dissolved. The natives were then moved to the Grande Ronde Reservation on the Oregon coast. Medford owes its origin in the early 1880s to the decision of the Oregon & California Railroad to construct a rail line on the alluvium in the middle part of the Bear Creek Valley. Initially, the community was called Middle Ford for the location at which the railroad would cross Bear Creek. The name Medford was proposed by the first railroad engineer, David Loring, who was from Medford, Massachusetts. The railroad reached Medford from Portland in January of 1884 and the town was incorporated on February 24, 1885. Over the 20th century, Medford has grown from a small railroad town to the largest city in southern Oregon with a population of over 68,000. Medford became the county seat in 1927, moved from the community of Jacksonville.

17.2 miles 27.5 km Community of Jacksonville. Approaching Jacksonville, South Stage road crosses the nonconformity separating the Cretaceous Hornbrook Formation from the underlying Triassic to Jurassic Hayfork terrane of the Klamath Mountains. Locally, the rocks of the Hayfork terrane are

5 composed of metavolcanics of andesitic to dacitic tuffs and volcanic agglomerates. Gold was discovered in the Oregon territory in Jackson Creek at Rich Gulch in 1851. Soon after, miners and settlers flocked to the Bear Creek Valley and the Klamath Mountains in search of gold. Several thriving mining camps emerged along the creeks and drainages of the Klamath Mountains. By early 1852, the bustling camp near Daisy and Jackson Creeks was transformed into Jacksonville, a town with numerous shops, saloons, banks, and gambling halls. Soon after, Jacksonville became the county seat and the hub of commerce in southern Oregon. In addition, vineyards were planted in southern Oregon near Jacksonville by Peter Britt in 1858. Britt’s vineyards covered approximately fifteen acres, producing a quality wine under the Valley View Vineyard label. Unfortunately the viticulture industry in southern Oregon substantially decreased after Britt’s death in 1905. Shortly thereafter, Oregon led the nation in prohibition legislation beginning in 1916. In 1884, the Oregon & California Railroad bypassed Jacksonville to follow the alluvial plain of the Bear Creek Valley toward the Siskiyou Summit. Medford became the primary link between the north and south stretches of the railroad. Jacksonville became the home to wealthy merchants who built grand mansions in the 1870’s and 1880’s. Jacksonville remained the county seat with the opening of a new County Court House in 1884. By the 1890's, agriculture replaced mining as the main industry in the Bear Creek Valley and the county seat was moved to Medford in 1927. At the far end of town, South Stage Road merges with Highway 238. Along Highway 238 there are several exposures of metamorphic rocks of the Triassic to Jurassic Hayfork terrane. Highway 238 follows Poorman’s Creek to the floodplain of Forest Creek to Ruch.

25.3 miles 40.5 km Town of Ruch. At Ruch, turn left onto Applegate Road (County Road 10). This road parallels the Applegate River to the south through metamorphic rocks of the Triassic to Jurassic Hayfork terrane of the Klamath Mountains. Approximately one mile from the intersection of Highway 238 with Applegate Road, the Wisnovsky family started the Valley View Winery in 1972, growing grapes and wine with a label similar to that of Peter Britt’s design. This winery marks the first production of wine in southern Oregon since the early 20th century.

33.4 miles 53.4 km One of the three remaining covered bridges in Jackson County, the McKee Bridge spans 122 feet across the Applegate River. The McKee Bridge was built in 1917 by the Jason Hartman Company of Jacksonville and once served a mining and logging route between Oregon and California. Ore from the Blue Ledge Mine was transported by wagon to the town of Copper and then by truck along the Applegate River to Jacksonville, and then to Medford. In Medford, the ore was loaded onto rail cars and

6 transported to Tacoma, Washington for processing by the American Smelting & Refining Company. The McKee Bridge was closed in 1956, but repairs in 1965 kept the bridge open to pedestrians until 2004.

40.1 miles 64.2 km Applegate Dam was authorized by the Flood Control Act of 1962 and construction was completed in 1980 by the U.S. Army Corps of Engineers. The dam provides flood control and irrigation to residents along the Applegate River in Jackson County, Oregon. Roadcuts along Applegate Road expose metabasalts, serpentinite, and diorite of the Triassic to Jurassic Western Hayfork terrane of the Klamath Mountains. Near the south edge of the reservoir, Applegate Road crosses the eastward dipping thrust separating the Jurassic Condrey Mountain terrane from the Hayfork. The Condrey Mountain terrane consists predominately of phyllite, graphite schist, chlorite schist, and quartz-albite-muscovite schist. The Blue Ledge Mine of the Elliott Mining District of the Klamath Mountains occurs within the Condrey Mountain terrane. Of historic significance is the town of Copper, now inundated by the reservoir. Copper was a small mining town providing a transfer point for ore carried by wagon from the Blue Ledge Mine to haul trucks that shipped the ore to Medford via Ruch and Jacksonville.

43.8 miles 70.1 km At the intersection of Applegate Road (Highway 10) with National Forest Road (NFR) 1040, turn left, following the paved road around the southern limit of Applegate Reservoir.

45.2 miles 72.3 km Oregon-California State Line. NFR 1040 merges into NFR 1050. Continue on NFR 1050 along the north side of Elliott Creek.

46.7 miles 74.7 km At the intersection of NFR 1040 with NFR 1060, turn right crossing Elliott Creek. Follow NFR 1060 to the Blue Ledge Mine.

46.9 miles 75.1 km Confluence of Joe Creek and Elliott Creek.

50.1 miles 80.2 km Arrive at Blue Ledge Mine, originally owned by Blue Ledge Mining Company of New York. The mine is located in the Elliott mining district of the Klamath Mountains. A portion of the 1:24,000 Dutch Creek quadrangle in Figure 3 provides more detail on the local topography. The mine is at an elevation of 4,300 feet and was connected by wagon roads to the old placer camp of Copper. The sulfide mineralization occurs in a north-south oriented vein, dipping nearly vertical, which can be traced for over 3,000 feet at the surface. The adit walls are composed of micaceous schist and phyllite. The recovered ore consists of primarily pyrite and chalcopyrite, with an average copper content of 6 percent. In the early stages of production from the mine, the Blue Ledge Mining Company planned to build a smelter on the Applegate River near Seattle Bar just upstream from the mining camp at Copper.

Figure 3: Portion of the Dutch Creek 1:24,000 topographic map of the Blue Ledge Mine and vicinity, Siskiyou County, California.

8 Blue Ledge Mine Mining History The Blue Ledge Mine is located at an elevation of 4,300 feet, approximately 3 miles south of the Oregon border in Siskiyou County, California. Prospectors from Crescent City, California discovered the sulfides in the vicinity of the Blue Ledge Mine in 1898. Development of the Blue Ledge mine occurred from 1904 to 1909 and was operated from 1917 to 1920, after a long period of inactivity. An estimated 66,906 tons of waste rock were dumped on the steeply inclined tailing slopes. The mine was not operated from 1921 to 1929. In 1930, Dr. J. F. Reddy and George Hughes produced and shipped 2,575 tons of ore by sorting the tailings of the mine and selectively removing ore from the abandoned adits (Hundhausen, 1947). The following table summarizes the production and grade of the ore from the Blue Ledge Mine. This table is modified from Hundhausen (1947).

Total Year 1917 1918 1919 1920 1930 production or average grade Tons, shipped 3,500 1,981 2,359 736 2,575 11,151 Gold, oz./ton (avg.) 0.09 0.09 0.09 0.12 0.09 0.09 Silver, oz./ton (avg.) 5.1 5.7 5.8 5.5 4.5 5.3 Copper, wt. % (avg.) 12.5 13.2 14.2 13.0 8.6 12.1

The Blue Ledge Mine is subdivided into seven levels with four main adits. The lowest adit has collapsed and numerous passages and winzes within the mine are flooded. The recovered ore consists primarily of chalcopyrite, pyrite, and sphalerite with subordinate amounts of pyrrhotite, galena, and arsenopyrite. Assays of a mine composite sample and a low-grade ore are summarized in the following table from Hundhausen (1947).

Mine Low Assay Composite Grade (percent) #15-4 Ore #15-5 Cu 3.63 2.42 Zn 4.1 2.8 Fe 24.95 14.0 Pb 0.15 0.10 SiO2 21.25 37.9 S 27.0 12.9 Mn 0.05 0.05 Co <0.01 <0.01 TiO2 0.1 0.15 CaO 2.6 3.2 MgO 0.65 0.95 Al2O3 8.53 15.25 Insoluble 32.5 59.0 Au (oz/ton) 0.05 0.03 Ag (oz/ton) 2.15 1.3 Spec. Grav. 3.68 3.20

9 Geology The Blue Ledge Mine is situated within metasedimentary and metavolcanic rocks of the Jurassic Condrey Mountain terrane in the Elliott Mining District of the Klamath Mountains (Koski and Derkey, 1981; Blake et al, 1982; Irwin, 1994). A U-Pb zircon date of 170 Ma was measured from a small pluton intruded into the Condrey Mountain terrane, providing a minimum age for the sedimentary and volcanic protolith (Coleman et al., 1983; Irwin, 1994). Metamorphic rocks in the vicinity of the Blue Ledge Mine include phyllite, talc schist, graphite schist, sericite schist, quartz-albite-muscovite schist, and chlorite schist. The mineralization at the Blue Ledge Mine varies from massive veins to brecciated sulfides within quartz-mica schist. The sulfide veins are heterogeneous assemblages constituted primarily of brecciated pyrite, chalcopyrite, and

py Figure 4: Polished thin-section of pyrite (py), chalcopyrite (ch), and sphalerite (sp) from the Blue py Ledge mine. The pyrite is ch sp brecciated and surrounded by disseminated chalcopyrite (ch), sphalerite (sp), and quartz (qtz). qtz Note that there are two modes of 0.5 mm pyrite crystallization.

sphalerite (Fig. 4) with subordinate amounts of pyrrhotite, galena, and arsenopyrite. The sulfide veins in the Blue Ledge Mine are constrained by quartz-mica, talc, and sericite schist (Hundhausen, 1947). The surrounding non-mineralized metamorphic rock is composed primarily of chlorite schist, quartz-albite-muscovite schist, graphite schist, and phyllite. The sulfide mineralization at the Blue Ledge Mine probably originated in a backarc basin from a submarine hydrothermal vent system (Koski and Derkey, 1981; Franklin, 1993; Sherlock et al., 2004). The sulfides were most likely encased in sedimentary and volcanic rocks, later metamorphosed by accretionary tectonics of the Klamath Mountains. The latest metamorphism in the Condrey Mountain terrane occurred in the Late Jurassic (Irwin, 1994). Consequently, the rocks are heavily faulted, fractured, and folded. During metamorphism, the deposit underwent recrystallization and secondary hydrothermal mineralization creating the present mineral assemblages.

Acid Mine Drainage Historical exploitation of sulfide mineralization within the Klamath terranes of southwestern Oregon and northern California has resulted in the current acid mine drainage (AMD) problems of the region. There are several examples in southern Oregon of severe environmental degradation due to AMD, including the Formosa Mine near Riddle, Oregon. Sulfide mineralization and disseminated sulfide minerals are well-exposed in the open adits and passages of the Blue Ledge Mine. Convective air flow through the mine workings combined with water flow down successive levels via numerous winzes provides for high dissolved oxygen levels in standing pools of water in the adits. Localized stalactites of hydrated oxides of iron, probably limonite or goethite, extend from the ceilings and cover the walls of several passages in the mine, consistent with oxidation of sulfide minerals by groundwater movement through the overlying bedrock. In addition, slimes are also locally abundant on the adit walls (Fig. 5).

10 B Figure 5: A. Standing pool of water in an A s g adit of the Blue Ledge Mine. Total dissolved solids are 550 ppm with a pH of l 2.3, measured in October of 2004. B. Slime (s) coating an adit wall in the Blue Ledge mine surrounded by limonite (l) and s goethite (g) on pyrite. The bacteria in this slime have not been identified. The l portion of the hammer shown in the g photograph is 20 cm in length.

Standing pools of water within adits of the Blue Ledge Mine have a pH of 2.3 to 2.6, total dissolved solids of 400 to 2,000 ppm, and dissolved oxygen concentrations between 4 and 10 mg/L (Fig. 5). The temperature of the standing pools within the open adits ranges from 4o to 8oC in the early spring and increases to between 10o and 14oC in the fall. Less than one cfs of this water is discharged from a lower adit and flows over the mine tailings into a small ephemeral tributary to the north of the mine. Flow from the lower adit is continuous throughout the year. Surface run-off during a rain event and groundwater percolating through the mine tailings also empty into the same run-off tributary channel. Below the mine tailings, this tributary has a flow of 1 cfs in the spring, becoming dry in the mid-summer. In spring, the acid mine discharge in the tributary has a pH of 3.1 to 3.8, total dissolved solids of 200 to 300 ppm, and a dissolved oxygen concentration of 10 to 11 mg/L. Annually, the first large rain event in the fall returns flow to the tributary north of the mine, triggering a rapid increase in dissolved solids of up to 1,000 ppm and a pH of 2.8 to 3.5 in the run-off. The rapid increase in dissolved solids and lowered pH is most likely due to the dissolution of hydrous sulfate minerals from the mine and tailings piles. This run-off, combined with the AMD flushed from pools within the mine, results in a plume of low pH, metal-laden effluent that is transported into Joe Creek and continues downstream for several hundred meters (Sherlock et al., 2004). Bed material within the tributary channel and in Joe Creek is coated with iron hydroxides, or “yellow boy”. In addition, macroinvertebrates, mollusks, and riparian vegetation are absent from Joe Creek, extending about 1 km (0.6 miles) below the confluence with the run-off tributary from the Blue Ledge Mine.

Current Research Projects Bill Elliott (Geology, SOU) and Steve Petrovic (Chemistry, SOU), along with several of their students, are currently engaged in a geochemical study of the AMD from the Blue Ledge Mine. In addition to the chemical study of the AMD, the geology of the mine and surrounding area is being mapped to better understand this natural system. Kathleen Page (Biology, SOU) is involved in assessing the biology of microbes associated with the AMD of this mine. Some of the preliminary research will be presented during this AAAS meeting.

11 References Cited Blake M. C., Jr., Howell, D. G., and Jones, D. L., 1982, Preliminary tectonostratigraphic terrane map of California: U.S. Geological Survey Open File Report 82-593. Coleman, R. G., Helper, M. D., and Donato, M. M., 1983, Geologic map of the Condrey Mountain Roadless area, Siskiyou County, California: United States Geological Survey Miscellaneous Field Studies, Map MF-1540-A. Scale 1:62,500. Franklin, J. M., 1993, Volcanic-associated massive sulphide deposits, in Kirkham, R. V., Sinclair, W. D., Thorpe, R. I., and Duke, J. M., eds., Mineral Deposit Modeling: Geological Association of Canada Special Paper 40, p. 315-341. Historic Discovery Drives, 1997, Southern Oregon Historical Society, Medford, Oregon, 18 p. Hundhausen, R. J., 1947, Blue Ledge Copper-Zinc Mine, Siskiyou County, California: U.S. Department of Interior - Bureau of Mines, Report of Investigations 4124, 16 p. Irwin, W. P., 1994, Geologic Map of the Klamath Mountains, California and Oregon: U.S. Geological Survey, Miscellaneous Investigations Series, Map I-2148. Scale 1:500,000. Koski, R. A., and R. E. Derkey, 1981, Massive sulfide deposits in oceanic-crust and island-arc terranes of southwestern Oregon: Oregon Geology, v. 43, no. 9, p. 119-125. Mortimer, N., and Coleman, R. G., 1984, A Neogene structural dome in the Klamath Mountains, California and Oregon, in Nilsen, T. H., ed., Geology of the Upper Cretaceous Hornbrook Formation, Oregon and California: Pacific Section, SEPM, v. 42, p. 179-186. Sherlock, W., Elliott, W. S., Jr., Petrovic, S. C., Page, K., and Graf, J., Jr., 2004, Effects of geomicrobiology on acid mine drainage in a polymetallic massive sulfide deposit, Blue Ledge Mine, Siskiyou County, California: Geological Society of America Abstracts with Programs, v. 36, no. 5, p. 361.