Добрый день, Коллеги. Важное сообщение, просьба принять участие. Музей Ферсмана ищет помощь для реставрационных работ в помещении. Подробности по ссылке
The Phanerozoic history of North America can be divided into three broad phases: During the first phase, which lasted from the Late Precambrian to the Triassic, Pangea was under construction. The western continental margin was either a divergent (‘‘passive’’) margin, facing the paleo-Pacific Ocean (Panthalassa) or a backarc basin bordering that ocean, while the eastern margin, beginning in the Middle Ordovician, underwent convergent and collisional tectonism, with the generation of the Appalachian orogen.
Etymology reveals much about the essence of a word. Science in German, Wissenschaft, is the art of observing whereas science in Chinese, koxue, is the study of classifying. Scientific observations, with the help of modern equipments, have made leaps and bounds in our century, but taxonomy seems irrelevant.
Classification can be science. The rise of the natural sciences in Europe could be traced back to Carl Linnaeus in 1750 when he used criteria of mutual exclusiveness to establish the taxonomy of living organisms. Unfortunately, this prerequisite in dividing and subdividing is not always appreciated, and a common practice in geology has been to "classify" basins through reference to incidental attributes. So, we have coastal basins, back-arc basins, extensionally rifted basins, uccessor basins, deep-sea basins, flysch basins, etc. These qualifications describe the geography, tectonic setting, principal stresses, orogenic chronology, depositional environment or sedimentary association of a basin, but these all could be different aspects of one and the same.
The modern geological sciences are characterized by extraordinarily rapid progress, as well as by the development and application of numerous new and refined methods, most of them handling an enormous amount of data available from all the continents and oceans. Given this state of affairs, it seams inevitable that many students and professionals tend to become experts in relatively narrow fields and thereby are in danger of losing a broad view of current knowledge.
Sedimentary basins are, in a very broad sense, all those areas in which sediments can accumulate to considerable thickness and be preserved for long geological time periods. In addition, there also exist areas of long-persisting denudation, as well as regions where ero-sional and depositional processes more or less neutralize each other (creating what is known as non-deposition or omission).
Our modern society has a constant need for raw materials and energy. An on-going effort in exploration and research is necessary, therefore, to discover and develop them. And, in this effort, it is better to appeal to geology than to rely on chance.
From May 3-5, 1999, more than 200 geologists assembled in Grieghallen, Bergen to discuss the sedimentary development of the Norwegian offshore areas and their analogues. The conference was organised by the Norwegian Petroleum Society. The participants came from universities, government agencies and oil and consulting companies in Norway, Denmark, Great Britain, Holland, France, Spain, Canada and USA. The presentations included 25 talks, 10 core examples and 37 posters. Particular emphasis was on the posters and the core examples, recognising that it was within these presentations that most of the data were presented. Three keynote addresses were given: by Robert Dalrymple on non- and marginalmarine environments, by H. Edward Clifton on shallow-marine environments, and by Arnold Bouma on deep-water environments. For various reasons, papers from these keynote addresses were not included in the volume, but their abstracts are included in the abstracts volume (Martinsen and Dreyer, 1999). <...>
The first edition of this book was conceived in 1974 to provide a comprehensive text, covering modern and ancient environments, suitable for advanced university students, research workers and professional geologists. To cover all environments and facies with the authority of an active research worker, we formed a group of authors who knew each other well and shared a similar philosophical view. We could criticize, amend and integrate each other's contributions, while retaining individual styles and responsibility for each chapter.
Sedimentary exhalative (sedex) deposits account for more than 50 percent of the world’s zinc (Zn) and lead (Pb) reserves (Tikkanen, 1986) and furnish more than 25 percent of the world’s current production of these two metals and a significant amount of silver (Ag) (Goodfellow and Lydon, 2007). More than 129 deposits of this type have been recognized in sedimentary basins around the world (Leach and others, 2005b; Goodfellow and Lydon, 2007). A compilation by Taylor and others (2009) shows that deposits occur in 25 sedimentary basins, 7 of which contain more than 10 million metric tons (Mt) of combined Pb+Zn (figs. 1, 2). In order of decreasing endowment, these basins are the Mt. IsaMcArthur basins, Australia (7 deposits containing 112 Mt of Zn+Pb metal); Selwyn basin, Canada (17 deposits, 55 Mt); Brooks Range, Alaska, United States (3 deposits, 40 Mt); Kholodninskoye deposit, Russia (1 deposit, 23 Mt); Rajasthan basin, India (5 deposits, 20 Mt); Belt-Purcell basin, United States and Canada (1 deposit, 19 Mt); and Rhenish basin, Germany (2 deposits, 11 Mt) (fig. 1). <...>
The Guaritas sequence is the uppermost stratigraphical level of the Camaqua Basin (southern Brazil) and comprises an alluvial, deltaic and aeolian continental facies association up to 800 m thick. Facies mapping of this unit has revealed a lateral association of tributary fans and trunk braided rivers developed under semi-arid conditions.
We substantially revised the first and second editions of this book while retaining our original objectives: to help you better understand (1) the processes that erode, transport, and deposit sediments (sedimentology); (2) the characteristics and origins of sedimentary rocks (sedimentary petrology); and (3) the complex distribution of the sedimentary rock record in space and time (stratigraphy). The first two areas are the subjects of Chapters 1 through 14. The field of stratigraphy is covered in Chapters 15 through 19.
