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The uranium minerals that today are at the centre of worldwide attention were unknown until 1780, when Wagsfort found a pitchblende sample in 10hanngeorgenstadt. This discovery passed unnoticed, however, since Wags fort thought that it contained a black species of a zinc mineral-hence the n':lme 'pitchblende' (= pitch-like blende). Seven years later, Klaproth, while examining the mineral, noted that it contained an oxide of an unknown metal, which he called 'uranium' in honour of the planet Uranus, recently discovered by Herschel. Klaproth also believed that he had separated the metal, but, in fact, the attempt failed, and uranium, given its strong affinity with oxygen, was not separated until several years later. In 1833 Arfwedson attempted the separation and, in so doing, reduced the pitchblende. His attempt was not successful and only U02 was obtained. It was Peligot, in 1840, who was finally successful. He managed the reduction of the metal working with metallic potassium. It should be remembered that twelve years earlier Berzelius had isolated thorium.
In the winter of 1969 a series of storms in the ‘drylands’ of southern California caused serious soil erosion, numerous landslides, and widespread flooding. Over a hundred people were killed, thousands of homes and other buildings were ruined, the total estimated damage exceeded $200 million, the lives of several million people in the sprawling Los Angeles metropolis were disrupted, and the resources of the community had to be mobilized to cope with the emergency and rehabilitate the region at a cost of well over $8 million (US Corps of Engineers, 1969). The dominant environmental processes responsible for this crisis - erosion, slope failure, and flooding - are geomorphological problems, problems relating to the nature of the land surface and the forces that act upon it. <...>
Structural geology is an important component in regional-, district- and orebody-scale exploration and development of sedimentary rock-hosted Au deposits. Identification of timing of important structural events in an ore district allows analysis and classification of fluid conduits and construction of genetic models for ore formation. The most practical uses of structural geology deal with measurement and definition of various elements that comprise orebodies, which can then be directly applied to ore-reserve estimation, ground control, grade control, safety issues, and mine planning. District- and regional-scale structural studies are directly applicable to long-term strategic planning, economic analysis, and land ownership <...>
Wawa has long been a center of mineral exploration activity and diamonds have been reported in the area since the 1930s. However, diamond exploration did not begin in the area in earnest until 1991. In 1993, Sandor Surmacz and Marcelle Hauseux of Saminex began a prospecting program in the area which culminated in their discovery of the “Sandor” diamond occurrence in an outcrop on the east side of the Trans-Canada Highway.
Over the last 20 to 30 years there has developed а large body of literature оп the statistical treatment of geochemical data. Some of this literature is in the form of warnings to the geochemical community that their practices are not sufficiently statistically rigorous. Other papers are concerned with improving the statistical techniques current amongst geochemists and they provide methods which are more appropriate to the peculiar properties of some geochemical data. Unfortunately, thete is а tendency to leave the whole subject of the statistical treatment of geochemical data 'to the experts' and consequently а large part of this literature is ignored Ьу most geochemists. This тау in part Ье because the journals in which the papers are located are specific to mathematical geology. Another reason, however, is that mathematical geologists tend to write in order to communicate with other mathematicians rather than with geochemists. Whatever the reason, the net effect is that for а long time geo-statisticians have Ьееп advising geochemists in the practice of their art and yet for the most part their words have seemed irrelevant and have gone unheeded <...>
QGIS is an open-source GIS program for the display and analysis of GIS data. It has developed significantly in the past few years and is now a valuable tool for the mineral exploration industry, and a viable alternative to the commercially available GIS packages. Although not specifically written for geological applications, QGIS can do most of the required GIS tasks required by today’s geoscientists. The terminology is different to the usual earth sciences programs, but many QGIS algorithms do the same thing but with a different name <...>
The great surge of interest and activity in exploration for uranium deposits over the last decade has added significantly to our knowledge of uranium geology and the nature of uranium deposits. Much of the information that has been developed by government and industry programmes has not been widely available and in many cases has not had the benefit of systematic gathering, organization and publication.
The Kokchetav subduction-collision zone (KSCZ) hosting ultrahigh- and high-pressure (UHP-HP) rocks underwent the multistage Vendian-Early Ordovician geodynamic evolution. The subduction of the Paleoasian oceanic lithosphere bearing blocks of continental crust and the collision of the Kokchetav microcontinent with the Vendian-Cambrian island-arc system ultimately led to the formation and exhumation of UHP-HP rocks. In the Vendian-Early Cambrian the margin of the Kokchetav microcontinent deeply subsided into the subduction zone (150–200 km), which led to UHP-HP metamorphism (the maximum at about 535 Ma) and to partial melting of its rocks. In next stage (535–528 Ma), the generated acidic melts including blocks of UHP-HP rocks quickly, at a rate of 1 m/year, ascended to depths of 90 km for 1 Myr. During subsequent 5 Myr, the UHP-HP rocks ascending at a rate of 0.6–1 cm/year reached the base of the accretionary prism (depths of 60–30 km). Then, in the period from 528 to 500 Ma, the UHP-HP rocks ascended along the faulting structures of the lower crust as a result of jamming the subduction zone by the Kokchetav microcontinent. During the period from 500 to 480 Ma, the UHP-HP rocks became part of the upper crust. This process led to the KSCZ, which comprises terranes of the Vendian-Early Arenigian subduction zone occurring at different depths, separated by zones of garnet-mica and mica schists, blastomylonites and mylonites. In the same period there was a jump of subduction zone, which led to the formation of the Ordovician Stepnyak island arc. As a result of the Late Arenigian-Early Caradocian microcontinent-island arc collisions (480–460 Ma), the KSCZ overrided upon the fore-arc trough of the Stepnyak island arc to form a thick accretion-collision orogen, which having experienced anatectic melting was intruded by collisional granites of the Zerenda complex 460–440 Ma in age.
To many, palaeontology in general, and vertebrate palaeontology in particular, might be seen as devoted to discovering new fossils. After all, we read lavish press reports of each new species of dinosaur, fossil bird, or early human fossil that is recorded in the scientific literature. Discoveries from all continents attract attention, and none moreso than the continuing rich haul of remarkable new fossils from China. Our understanding of fossil vertebrate evolution has been much enriched by continuing discoveries of basal chordates from the Chengjiang and associated exceptional faunas of South China, as well as the feathered birds and dinosaurs from the Jehol assemblages in North China. But, as any young palaeobiologist knows, the discovery of new species is a minor concern. Much more exciting has been the blossoming of new numerical techniques that extend the reach of studies in macroevolution and palaeobiology further than might have been imagined even ten years ago.
Vesuvianite-group minerals (VGM) are widespread and occur in different geological formations including regional metamorphic rocks, skarns, rodingites, etc. Specific crystal-chemical features of these minerals reflect conditions of their crystallization. As a rule, high-temperature VGM have high-symmetry structures (space group P4/ nnc), whereas low-temperature samples are characterized by the symmetry P4/n or P4nc (Allen and Burnham 1992).
