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Ordinary kriging and non-linear geostatistical estimators are now well accepted methods in mining grade control and mine resource estimation. Kriging is also a necessary step in the most commonly used methods of conditional simulation used in the mining industry. In both kriging and conditional simulation, the search volume or ‘kriging neighbourhood’ is defined by the user. The definition of this search can have a very significant impact on the outcome of the kriging estimate or the quality of the conditioning of a simulation.
Nickel, copper, and cobalt resources in undiscovered Ni-Cu deposits associated with Palaeoproterozoic synorogenic intrusions and Archaean and Palaeoproterozoic komatiitic volcanic rocks have been estimated down to the depth of one kilometre in the bedrock of Finland using the three-part quantitative assessment method. Grade-tonnage models were constructed for Finnish synorogenic intrusive deposits and komatiitic deposits using data from known Fennoscandian deposits. Twenty-six permissive tracts were delineated for synorogenic intrusive deposits, 30 for komatiitic deposits, and 15 for Talvivaaratype Ni-Zn-Cu-Co deposits.
Every day, somewhere in the world, decisions are made about how public lands that might contain undiscovered resources should be used or whether to invest in exploration for minerals. Less frequently, decisions are made concerning mineral resource adequacy, national policy, and regional development. Naturally, the people making the decisions would like to know the exact consequences of the decisions before the decisions are made. Unfortunately, it is not possible to inform these decision-makers, with any certainty, about amounts, discoverability, or economics of undiscovered mineral resources.
Plate tectonics focuses on the dynamics and kinematics of the most external layers of the solid Earth: the relatively thin oceanic crust (7–10 km thickness), the continental crust (5–70 km thickness), the mantle lithosphere, whose lower boundary can be found at depths ranging between 80 and 250 km, the underlying asthenosphere (up to 410 km depth), the transition zone (410–670 km depth), and the very huge lower mantle, which extends to a depth of 2,900 km (Fig. 1.1). All these rock layers are formed by solid-state mixtures of minerals that are chemically and structurally stable only within determined intervals of pressure and temperature. Rocks can eventually contain liquid phases in the existing pores between grains or in cracks.
Processes involved in the development of igneous and metamorphic rocks involve some combination of crystal growth, solution, movement and deformation, which is expressed as changes in texture (microstructure). Recent advances in the quantification of aspects of crystalline rock textures, such as crystal size, shape, orientation and position, have opened new avenues of research that extend and complement the more dominant chemical and isotopic studies.
The present contribution examines the relationship between pressure solution and the crystallographic orientation of detrital quartz in cleaved sandstones which exhibit a high degree of pressure solution. The majority of the detrital grains examined have undergone pressure solution and as a result they have acquired smooth truncated margins along certain cleavage planes. The amount of pressure solution varies significantly among the detrital grains. This analysis indicates that quartz offers variable resistance to pressure solution along different crystallographic directions. Quartz grains with a small angle between c-axis and the Z-axis of shortening exhibit the least amount of pressure solution, whereas grains with oaxes oriented about 50° to Z manifest the highest degree of the pressure solution.
The contributions of this book arose from a conference on "Mineralogy and analytics of highpurity Si02 raw materials" held in June 2011 in Freiberg, Germany. The 15 chapters are written by international experts and reflect the state of the art in the field of quartz and silica raw materials. The book covers the broad field of Si02 minerals and rocks and shows the progress made during the last decades in the evaluation of deposits and the application of advanced characterization methods to study the genesis and properties of these materials.
In the broad sense the subject of this book belongs to the properties and specifics of both natural and synthetic materials of the Si02 system. The chapters are dealing mainly with the mineral quartz, which is one of the most frequent minerals of the Earth's crust and also an important raw material in the industry. Therefore, the book is addressed to graduate students and scientists in mineralogy, geology, chemistry, physics, materials science and engineering, as well as to people from the industry, who are working with the processing and technical application of quartz and Si02 material.
"Quaternary Glaciations- Extent and Chronology, Part II: North America", edited by Jtirgen Ehlers and Philip Gibbard is the second volume of three, covering Quaternary glaciations across the Earth. Part I covered Europe, and Part III will cover South America, Asia, Africa, Australia and Antarctica. Together these three volumes form the second publication in the Elsevier Book Series on "Developments in Quaternary Science".
This new edition of Quaternary Glaciations—Extent and Chronology gathers together the evidence of glaciation from around the world in 77 chapters. The book combines all regions of the world into one volume and provides a closer look at the extents, timing, and wider significance of Quaternary glaciations. The main advances reported in this book include better understanding of the timings of glaciations — especially through the application of cosmogenic nuclide analyses—and better understanding of the detailed extent and subdivision of different glaciations.
