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Album caption and index card: Looking east at the Maxwell breccia reef near the junction of Fourmile Creek and North Boulder Creek. At this exposure the reef consists of brecciated Boulder Creek granite, moderately silicified and stained with hematite. The breccia reef has been mapped previously as pegmatite dike cutting the granite. Boulder County, Colorado. Notes: Published as figure XX-A in U.S.Geological Survey. Professional Paper 223. 1950.
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Album caption and index card: Unmineralized part of tungsten vein 200 feet west of large ore shoot, 100-foot level of Tungsten Vein mine. Note interior faulting and drag in barren sheeted zone (sz), showing the hanging wall (hw) has dropped. Boulder County, Colorado. Notes: Published as figure XXII in U.S.Geological Survey. Professional Paper 223. 1950.
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Album caption and index card: Front range of the Rocky Mountains from near Gray's and Torrey's Peaks. This view is very nearly due north, looking down on the spur of Mount McClellan, and directly opposite from Gray's Peak. Beyond is James Peak, and the range about it. Along the horizon is Long's Peak, and the range running west from it, forming the boundary between North and Middle Parks. Clear Creek, Grand and Boulder Counties, Colorado. 1873. (Panorama with nos. 1310-1311; jwh01310-jwh01311; 1313 - 1315; jwh01313, jwh01314, jwh01315).
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Album caption and index card: Photomicrograph of gold-tungsten ore from Keklonga mine, Magnolia district. Sylvanite (s) in vuggy quartz (q3) which contains a little pyrite (py). Quartz (q3) and ferberite (fe) cut in early quartz. Boulder County, Colorado. Notes: Published as figure LXXIV-B in U.S.Geological Survey. Professional Paper 223. 1950.
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Album caption and index card: Photomicrograph of quartz-biotite schist from Idaho Springs formation at Nederland. Original bedding (nearly vertical in photograph) is intersected by shear planes sloping down to right at about 45°, and these shears are cut by later shears sloping to the left at 60°. b, Biotite; g, garnet; m, magnetite; q, quartz; fqb, crushed feldspar, quartz, and biotite. Plain light. Boulder County, Colorado. Notes: Published as figure VII-C in U.S.Geological Survey. Professional Paper 223. 1950.
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The Castle Rock in Boulder Canyon. The canyon is about 17 miles in length, cutting deep down through the metamorphic rocks of the foothills, so that in some places the sides of the canyon rise up nearly 3,000 feet above its bed. Boulder County, Colorado. 1873.
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Album caption and index card: View of the Colorado or Front Range from near Gold Hill, as seen from Bald Mountain, about 3 miles west from the Ward mining district, embracing a view from Long's Peak on the north, to near Arapahoe on the south. In the foreground is one of the little snow-fed lakes, so numerous throughout the mountains, and forming a pleasant variety to the monotony of numberless snow-white peaks. Although this view was made late in June, it will be seen that the hillsides are heavily draped in a mantle of snow, lying very deep through all the forest. The difficulty of reaching even this altitude was very great, requiring most laborious plunging through the thick timber and deep drifts. At the extreme...
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Album caption and index card: Photomicrograph of intrusion breccia of group 11 from Logan mine, 5 miles west of Boulder. Highly fragmented granite and some porphyry and early vein material lie in a biotite-flecked glassy groundmass that is partly silicified and sericitized. b, Fragment of biotite latite; g, glassy groundmass. Crossed nicols. Boulder County, Colorado. Notes: Published as figure XVII-A in U.S.Geological Survey. Professional Paper 223. 1950.
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Eldorado Springs, looking westward up the canyon, showing hills of hard massive red sandstone of the Fountain and Ingleside formations standing nearly vertical where cut by Eldorado Creek. Boulder County, Colorado. 1922. Plate 4-A in U.S. Geological Survey. Professional paper 149. 1927.
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Crystallized ferberite from the Georgia A. Mine, Nederland; coated with ammonium chloride. X 10. Boulder County, Colorado. 1910. Plate 8-B in U.S. Geological Survey. Bulletin 583. 1914.
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Open cut on the "Copeland property" of the Primos Exploration Company, South Boulder Creek, 1 1/2 miles north of Boulder looking north. Boulder County, Colorado. March 6, 1917.
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Long's Peak, a view from Estes Park on the northwest. Distance of about 12 miles from the summit. The park is about 4 by 6 miles in diameter, lying inside the foot-hill range and close under the main range. Long's Peak, as seen from the plains, in the most prominent in the front range, rising sharply high above the surrounding peaks. Its elevation is 14, 271 feet, and about 6,300 feet above the park. Boulder and Larimer Counties, Colorado. 1873.
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Album caption and index card: Photomicrograph of gold-tungsten ore from west end of 280-foot level of Keklonga mine, Magnolia district. Sylvanite (s) in crustified quartz (q₁ and q₂) associated with early coarse-grained ferberite. Fine-grained ferberite with a little quartz lies on the earlier quartz and is in turn incrusted and veined by late quartz (q3) containing some ferberite of three generations (f1, f2, and f3). py, Pyrite. Boulder County, Colorado. Notes: Published as figure LXXIV-A in U.S.Geological Survey. Professional Paper 223. 1950.
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Lowest workings. Workings of the Mojave Boulder Tungsten Mining Company on its Good Friday claim in the northeast side of the junction between North Boulder and Middle Boulder Creeks, just below Boulder Falls, 8 miles west of Boulder, Boulder County, Colorado. 1917.
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Contact of Fountain formation of granite, west of Lyons. Colorado. 1910.
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Panorama of the Wolf Tongue Mining Company, the Gale mine, 2 1/2 miles north of Nederland. Boulder County, Colorado. February 27, 1917.
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Hornblende schist of Idaho Springs formation: intruded by pegmatite near Eldora. Boulder County, Colorado. Circa 1911. Plate 12-B in U.S. Geological Survey Professional Paper 94. 1917.


map background search result map search result map Hornblende schist of Idaho Springs formation: intruded by pegmatite near Eldora. Boulder County, Colorado. Circa 1911. Castle Rock, Boulder Canyon. Boulder County, Colorado. 1873. View of the Front Range from near Gold Hill, as seen from Bald Mountain. Boulder County, Colorado. 1873. Long's Peak, a view from Estes Park on the northwest. Distance of about 12 miles from the summit. Boulder and Larimer Counties, Colorado. 1873. The Castle Rock in Boulder Canyon. Boulder County, Colorado. 1873. Front range of the Rocky Mountains from near Gray's and Torrey's Peaks. Clear Creek, Grand, and Boulder Counties, Colorado. 1873. The Colorado or Front Range from Bald Mountain near Gold Hill. Boulder County, Colorado. 1873. Hills of hard massive red sandstone of the Fountain and Ingleside formations. Boulder County, Colorado. 1922. Photomicrograph of quartz-biotite schist from Idaho Springs formation at Nederland. Boulder County, Colorado. circa 1932. Photomicrograph of intrusion breccia, west of Boulder. Boulder County, Colorado. circa 1932. Looking east at the Maxwell breccia reef near the junction of Fourmile and North Boulder Creeks. Boulder County, Colorado. circa 1932. Unmineralized tungsten vein. Boulder County, Colorado. circa 1932. Gold-tungsten ore from west end of 280-foot level of Keklonga mine. Boulder County, Colorado. 1932. Photomicrograph of gold-tungsten ore from Keklonga mine. Boulder County, Colorado. 1932. OFR 06-79 - Detection of Lost Oil Well Casings and Unknown Water Filled Voids in Coal Mines Through Development of a Microwave Antenna System. 1979. Hornblende schist of Idaho Springs formation: intruded by pegmatite near Eldora. Boulder County, Colorado. Circa 1911. Castle Rock, Boulder Canyon. Boulder County, Colorado. 1873. View of the Front Range from near Gold Hill, as seen from Bald Mountain. Boulder County, Colorado. 1873. The Castle Rock in Boulder Canyon. Boulder County, Colorado. 1873. The Colorado or Front Range from Bald Mountain near Gold Hill. Boulder County, Colorado. 1873. Hills of hard massive red sandstone of the Fountain and Ingleside formations. Boulder County, Colorado. 1922. OFR 06-79 - Detection of Lost Oil Well Casings and Unknown Water Filled Voids in Coal Mines Through Development of a Microwave Antenna System. 1979. Long's Peak, a view from Estes Park on the northwest. Distance of about 12 miles from the summit. Boulder and Larimer Counties, Colorado. 1873. Front range of the Rocky Mountains from near Gray's and Torrey's Peaks. Clear Creek, Grand, and Boulder Counties, Colorado. 1873. Photomicrograph of quartz-biotite schist from Idaho Springs formation at Nederland. Boulder County, Colorado. circa 1932. Photomicrograph of intrusion breccia, west of Boulder. Boulder County, Colorado. circa 1932. Looking east at the Maxwell breccia reef near the junction of Fourmile and North Boulder Creeks. Boulder County, Colorado. circa 1932. Unmineralized tungsten vein. Boulder County, Colorado. circa 1932. Gold-tungsten ore from west end of 280-foot level of Keklonga mine. Boulder County, Colorado. 1932. Photomicrograph of gold-tungsten ore from Keklonga mine. Boulder County, Colorado. 1932.