Geology and Mines of the Upper Blackfoot Valley, Montana

The purchase and continued operation of the Mike Horse mine in the Heddleston district, by the American Smelting and Re­fining Company, gives the Blackfoot Valley a renewed promise of a prosperous future in its role as a mining district. In the past, large amounts of placer gold were recovered from the gulches of the area, however, because of the transporta­tion facilities, only the upper portions of a few lodes were exploited by the early miners.

General Geology and Mines of Northwestern Montana

The five counties discussed in this paper compose the northernmost and westernmost counties in Montana. On the eastern boundary are Glacier National Park and the Continental Divide; on the southern boundary are Missoula and Powell counties; Idaho lies on the southwestern and western side; and the Canadian border lies along the northern edge. The region is on the Pacific Ocean side of the Rocky Mountains. Three major rivers, the Clark Fork, the Flathead, and the Kootenai drain this area into the Columbia River.

The Geology and Ore Deposits of the Ermont Mines

The Ermont Mines are located sixteen miles northwest of Dillon, Montana, in section 35 of T.6S., R.11W. This is in the central part of Beaverhead County. They are considered to be in the Argenta min­ing district, the town of Argenta lying three miles to the northeast.

Einige Nachrichten über die Juden in Abyssinien : (Aus Bruce Reisen nach Abessinien)

L. L.

Edith Bruce, Rollenbild, Kniestück

Signatur des Originals: S 36/F08306

Opernszene, in: Gioacchino Rossini: Robert Bruce

Signatur des Originals: S 36/G02663

Pauline Dameron als Marie, Rollenbild, Kniestück, in: Gioacchino Rossini: Robert Bruce

Signatur des Originals: S 36/G02930

Tab. 1: Trace-element concentrations in ore samples collected from mercury mines and deposits in southwestern Alaska

A belt of small but numerous mercury deposits extends for about 500 km in the Kuskokwim River region of southwestern Alaska. The southwestern Alaska mercury belt is part of widespread mercury deposits of the circum Pacific region that are similar to other mercury deposits throughout the world because they are epithermal with formation temperatures of about 200 °C, the ore is dominantly cinnabar with Hg-Sb-As±Au geochemistry, and mineralized forms include vein, vein breccias, stockworks, replacements, and disseminations. The southwestern Alaska mercury belt has produced about 1400 t of mercury, which is small on an international scale. However, additional mercury deposits are likely to be discovered because the terrain is topographically low with significant vegetation cover. Anomalous concentrations of gold in cinnabar ore suggest that gold deposits are possible in higher temperature environments below some of the Alaska mercury deposits. We correlate mineralization of the southwestern Alaska mercury deposits with Late Cretaceous and early Tertiary igneous activity. Our 40Ar/39Ar ages of 70 ±3 Ma from hydrothermal sericites in the mercury deposits indicate a temporal association of igneous activity and mineralization. Furthermore, we suggest that our geological ancl geochemical data from the mercury deposits indicate that ore fluids were generated primarily in surrounding sedimentary wall rocks when they were cut by Late Cretaceous and early Tertiary intrusions. In our ore genesis model, igneous activity provided the heat to initiate dehydration reactions and expel fluids from hydrous minerals and formational waters in the surrounding sedimentary wall rocks, causing thermal convection and hydrothermal fluid flow through permeable rocks and along fractures and faults. Our isotopic data from sulfide and alteration minerals of the mercury deposits indicate that ore fluids were derived from multiple sources, with most ore fluids originating from the sedimentary wall rocks.

Artes plásticas, Performance y Literatura : Bruce Nauman y las puestas visuales de Rodrigo García

La influencia de los medios visuales y las nuevas tecnologías en el arte, la literatura y la comunicación, nos conduce al problema de las relaciones entre la palabra y la imagen. Considerando las puestas del dramaturgo hispano argentino Rodrigo García, nos preguntamos por la influencia de las artes plásticas en su performance; identificando la influencia de la obra de Bruce Nauman, reflexionamos acerca de los vínculos entre imagen y texto identificando la confluencia de estéticas provenientes de distintos sistemas artísticos, y señalamos finalmente la importancia de la representación del cuerpo, en relación con el exceso y la abyección, en las nuevas poéticas contemporáneas