Red Dog is a Mississippian to Permian aged sulfide deposit located in the western Brooks Range north of Kotzebue, Alaska. It belongs in the family of black shale hosted sedimentary exhalite deposits but lacks classic sulfide sedimentary textures. Pervasive silicification, and a significant portion of the mineralization, is replacement in nature. An extensive feeder vein … Read more
IESG is an inexpensive but valuable component of our interdisciplinary integrated effort to discover and to understand hydrothermal convective plumbing systems, with originally hot, reducing, upward-flowing components yielding present negative IESG anomalies, and with originally cold, oxidizing, downward-flowing components yielding present positive IESG anomalies. This technique should facilitate the meaningful sampling of subtle Carlin-type invisible … Read more
Using this summary page you can locate Geological Maps from the MTO Online service in British Columbia to acquire Mineral Titles, Mining Claims. Mineral Title means a claim or lease acquired and maintained under the Mineral Tenure Act and its predecessor Acts (the Mineral Act and the Placer Mining Act) and these are by far the … Read more
Epithermal gold deposits occur in and near the marginal fault that circumscribes the Goldfield, Nevada, Tertiary caldera. The gold occurs disseminated in alunite, pyrite, and kaolin- bearing silicified zones that are controlled by the circular faults. Other Tertiary calderas (i.e., Summitville and Red Mountain No. 3) have epithermal disseminated gold deposits located in and near … Read more
Lupin is located on the shores of Contwoyto Lake at lat. 65° 48’N, Long. 111° 15’W and lies about 80 kilometres south of the Arctic Circle. Since start up in 1982 the mine has produced over 2.15 million ounces of gold from 6.66 million tonnes of ore grading 10.63 gm/tonne. Total remaining reserves at 1993 … Read more
Factors Controlling the Strength of Weak Rock Masses: For the purposes of this paper a weak rock mass is defined as any rock mass in which the effective shear strength parameters are less than: effective cohesion, c’ = 25 psi (0.2 Mpa) effective friction angle, ∅’ = 30° using the Mohr Coulomb failure criticism. This would … Read more
Stratigraphy The stratigraphic sequence in the Carlin Trend Geological area is Lower Paleozoic marine sediments and Late Tertiary tuffaceous sediments. The Lower Paleozoic sediments consist of the Siluro-Devonian Roberts Mountains Formation, the Devonian Popovich Formation and the locally named Rodeo Creek Formation. The Rodeo Creek Formation had previously been described in the mine area as … Read more
Worldwide, diatomites occur within Tertiary to Recent lacustrine and marine sediment facies (see Table 1). Geologically, the oldest marine and lacustrine diatoms predate the effusive blooms of the post Oligocene depositional period, and are respectively found within Cretaceous and late Eocene sediments. In the U.S., marine species are found in rocks as old as the … Read more
The sampling of placer deposits by drilling or, more precisely, drive-pipe sampling, is discussed in detail by Janin. He states that the Keystone no. 3 traction machine is used generally in California. The usual casing is 6 inches inside diameter and 3/8 inch thick, in 5- to 7-foot sections. Drilling without casing is not good … Read more
Failure to sample and estimate properly the available yardage of placer deposits has resulted in a tremendous waste of money and effort. A large proportion of all placer operations has failed because the gold in the gravel was insufficient to repay the cost of even the most efficient mining, not to mention the return of … Read more