Добрый день, Коллеги. Важное сообщение, просьба принять участие. Музей Ферсмана ищет помощь для реставрационных работ в помещении. Подробности по ссылке
This book got its start about seven years ago when Robert Bakker-the progressive dinosaurologist I studied with for many years-suggested that I draw up illustrations of some predatory dinosaur skeletons. About the same time, I started looking into the problem of bird origins, which I believed was tied to dinosaurs. One thing led to another and after a while I realized I had enough material available to put together a book on the dinosaurian meat eaters.
In the last 15 years the concept of mineral systems approach to understanding orogenic gold systems has been developed. The orogenic gold model, as defined by Groves et al. (1998) argues for gold to be deposited during compressional deformation in accretionary orogens, from hydrothermal fluids derived from the metamorphism of greenstones. These deposits are typically found in late Archaean or in Palaeoproterozoic greenstone belts (Groves et al., 2007) and include the world class gold provinces of Yilgarn Craton, Superior Province, the Birimian of West Africa and the Tanzania Craton.
Modelling and prediction of spatially distributed data such as the secondary cassiterite mineral distributions are often affected by spatial autocorrelation (SAC); a phenomenon that violates attributes data independence in space, which leads to type1 errors in classical statistics and overfitting or underfitting in machine learning (ML) classification respectively. The concept of overfitting and underfitting of spatially distributed datasets in an ML classification has not been properly addressed by the traditional random holdout technique of model validation, and this is a challenge to the assessment of predictive spatial model performance in spatially distributed datasets.
Palaeontologists can no more stop digging up fossils than stop breathing – it’s an obsession! Australasian palaeontologists are particularly driven to do this because the biological histories of Australia and its smaller neighbour, Zealandia, are the least understood of all the occupied continents.
В сборник вошли статьи, посвященные разным аспектам палеонтологии и охраны уникальных местонахождений ископаемых животных и растений. Важное место в книге отведено вопросам музееведения, хранения и экспонирования палеонтологических коллекций, а также методическим приемам изучения различных ископаемых остатков. Рассмотрены вопросы морфологии и систематики разных групп ископаемых организмов: цианобионтов, аммоноидей, высших растений (сфенофиллов, птеридоспермов, гинкгофитов). Книга предназначена для специалистов-палеонтологов, сотрудников профильных и региональных музеев, а также всех лиц, интересующихся вопросами естествознания и историей органического мира Земли.
Exploration is looking for minerals by means of surveys, drilling and taking samples. This includes extracting minerals for purposes other than producing them commercially. <...>
These exercises have been made to fit the content of the book Pressure Control During Oil Well Drilling http://bookboon.com/no (a book that was revised and updated in 2011, mostly on basis of input from readers). Many of the exercises in present book have been solved by students in the corresponding course at the Department of Petroleum Engineering and Applied Geophysics at NTNU of Trondheim, Norway. It would be highly appreciated if you contacted me at pal.skalle@ntnu.no in case there is something unclear in this collection of exercises.
The enhancement of dissolution of quartz under the influence of clays has been recognized in sandstones for many years. It is well known that a grain of quartz in contact with a clay flake dissolves faster than when in contact with another grain of quartz. This phenomenon promotes silica transfer during the diagenesis of sandstones and is responsible of deformation and porosity variations. Here we make an attempt to explain the process of this rock deformation using a pressure solution mechanism.