Добрый день, Коллеги. Важное сообщение, просьба принять участие. Музей Ферсмана ищет помощь для реставрационных работ в помещении. Подробности по ссылке
This book aims to give the first comprehensive explanation of the metallogenic areas of Fennoscandia, which have recently been described in the Metallogenic Map of the Fennoscandian Shield. The Fennoscandian metallogenic map shows the extent of presently known metallogenic areas.
Many Third World and developing countries rely mainly on the utilisation of their natural resources to sustain their economic development. In the Philippines in particular, the exploitation of mineral resources has traditionally been a significant component of the Philippine economy (Domingo, 1993).
В Геологическом сборнике Словацкой академии наук — Geologica Carpathica — публикуются оригинальные статьи по результатам научных исследований альпийско-карпато-балканской системы, тектонике, стратиграфии, палеонтологии, геологии месторождений полезных ископаемых, геохимии, минералов и петрографии. Кроме того в сборнике печатаются официальные материалы секции Карпато-Балканской Геологической Ассоциации, рецензии трудов и друше статьи библиографического характера.
Comme tous les êtres vivants, depuis qu’il existe, l’Homme doit non seulement assurer sa nourriture, condition essentielle de sa maintenance, mais il doit aussi faire face aux conséquences des manifestations internes et externes de son environnement. Ces interactions entre l’Homme et son cadre de vie représentent une préoccupation majeure permanente, puisqu’elles conditionnent notre vie et l’évolution biologique de tous les êtres vivants.
Dans la préface de notre premier volume nous avons fait, pour ainsi dire, l’histoire du livre que nous présentons au public; nous avons dit quelles circonstances nous avaient réunis dans une pensée commune, quels liens d’amitié s’étaient formés entre nous, et comment la haute protection de Sa Majesté Impériale et celle du ministre éclairé qui présidait alors au département des finances et des mines, nous avaient encouragés et secondés dans l’exécution d’un projet, qui nous paraissait d’abord au dessus de nos forces.
The Collahuasi district is located in northeastern Chile, approximately 200 km southeast of the port of Iquique. It defines an area of 1200 km2 in the Western Cordillera of the Andes Mountains, between altitudes of 4000 and 5000 m above sea level. The district hosts a cluster of mineralised centres that currently comprise three porphyry copper, associated high level epithermal vein, and palaeogravel-hosted exotic copper deposits. The Quebrada Blanca, Ujina and Rosario porphyry copper deposits are currently in production, as are the Huinquintipa exotic copper accumulations. The Collahuasi porphyry deposits are spatially associated with the West Fissure/Domeyko Fault System and appear to have been emplaced during a period of dextral transpression between 35-34 Ma.
Update of the Geologic Setting and Porphyry Cu-Mo Deposits of the Chuquicamata District, Northern Chile
Geologic Overview of the Escondida Porphyry Copper District, Northern Chile
Geologic Setting and Evolution of the Porphyry Copper-Molybdenum and Copper-Gold Deposits at Los Pelambres, Central Chile
Protracted Magmatic-Hydrothermal History of the Río Blanco-Los Bronces District, Central Chile: Development of World’s Greatest Known Concentration of Copper
Geology of the Bingham Canyon Porphyry Cu-Mo-Au Deposit, Utah
Geology and Exploration Progress at the Resolution Porphyry Cu-Mo Deposit, Arizona
Molybdenum (Mo) is a transition metal with an atomic number of 42 and a relative atomic mass of 95.95. Important isotopes are 95Mo, 96Mo, and 98Mo. Molybdenum has a high melting point of 2623 C and one of the lowest coefficients of thermal expansion among commercially used metals. It readily forms hard, stable carbides in alloys and is widely used in steel alloys, including high-strength alloys and superalloys. Molybdenum was discovered in 1781 by Peter Jacob Hjelm and the name is from the Greek “molybdos,” which means “lead,” because it was often confused
with lead. Details on the chemistry and uses of molybdenum can be found at www. rsc.org/periodic-table/element/42/molybdenum.
Barneys Canyon is a sediment-hosted, disseminated gold deposit located 7 km from the large, gold-rich, Bingham porphyry copper deposit. Host rocks for gold mineralization are the Permian Park City dolomite and siltstone and the Kirkman-Diamond Creek sandstone. The gold deposit is approximately 430 m long, 370 m wide, up to 90 m thick and contains 8.5 million metric tons (t) of reserves averaging 1.6 g/t gold. Intrusive igneous rocks are conspicuously absent. The gold deposit is located on the northern flank of the northeast-trending Copperton anticline, an overturned box fold. A small east-striking, south-dipping thrust fault, the Barneys Canyon thrust fault, with 200 m displacement, repeats the Park City Formation, and north-south-striking steep normal faults form a graben in which the gold deposit is located. The Barneys Canyon thrust fault predates mineralization and the Phosphate normal fault postdates mineralization.
Gold has been discovered recently at Cortez, Nevada, about 45 miles southwest of Carlin in carbonate rocks in a window of the Roberts Mountains thrust. The host rock consists of laminated to thin-bedded dark- to light-gray, silty dolomitic limestone and calcareous dolomitic siltstone in the upper part of the Silurian Roberts Mountains Limestone. These rocks contain sparse pyrite cubes and aggregates and some organic carbon. The rocks have been faulted and folded repeatedly during their complex geologic history. The gold is disseminated in a large zone where the rocks have been fractured and bleached and the pyrite oxidized. During oxidation the iron was redistributed, giving the rock a color ranging from light gray to dark red. The alteration zone envelops a 34-m.y.-old intrusive body of biotite-quartz-sanidine porphyry, which is also altered. No genetic relationship between the mineralization and the intrusive body is known. Silicification, iron-oxide staining, decalcification and, in extreme cases, dedolo-mitization generally accompanied the gold metallization, although any one of these phases of hydrothermal alteration may have been well developed without introduction of significant amounts of gold. Some clay alteration occurred in the igneous rock but none in the ore body. The gold is in micron-sized particles of native gold. Gold is mostly with silica between original silt grains and to a lesser extent in quartz-filled microfractures and hematite-goethite pseudomorphs after pyrite.
The gold was discovered during the examination of an arsenic-antimony-tungsten-mercury geochemical anomaly known in the area. Other gold deposits in north-central Nevada are associated with such anomalies.