The Geology Of The Guiana Shield

The Guiana Shield is an area of special importance, especially to those concerned with Precambrian geology because it provides a perspective on a part of Earth history not well represented elsewhere. For economic geologists, its mineral resource potential is just beginning to be understood. This overview of current knowledge will greatly help geologists already working in the area, draw attention to the need for mineral exploration research, and encourage the inclusion of the Shield in future Precambrian studies.

The Guiana Shield is an ancient geological formation located in the northern part of South America, covering an area of one million square kilometres. Despite its hostile environment, it is home to many unusual and highly specialized plants and animals, which constitute a rich area of biodiversity. Chapters in this book include hydrology, nutrient cycling, forest phenology, insect-plant interactions, forest microclimate, plant distributions, forest dynamics and conservation and management of flora and fauna. It provides a comprehensive and detailed review of the ecology, biology and natural history of the forests of the area.

This work intent to give an introduction to the basic principles and concepts of geology for all those are interested in the understanding and learn about all the processes and phenomena that formed and shaped the Earth, since its formation, around 4,800 million years before present (BP). Early geologists, makes its task of studying and interpreting these processes, contributed to display the history of the planet and the origin of the life. Their work were the basis for future generations of scientists deepened and made new discoveries that contributed in the understanding of our planet and give a new view about its formation. Thanks to all these discoveries, geologists were able to put all the pieces together and understand all the processes that contributed to the formation of the South American continent that began in the first moments of the formation of the Earth’s crust 3,800 million years BP. This book, compile the geological history of the continent into a single text, while pointing out new aspects that were not covered at first.

This book provides a comprehensive overview of the geological evolution of the Northern Andes and contiguous shield areas, with a focus upon Colombia. Updated geological interpretations are supported by modern lithogeochemical, seismic, gravity and magnetic data and radiogenic isotope and radiometric age determinations. The composite data permits a detailed interpretation of the tectono-magmatic history of the Northern Andean Block, including the Andes of Colombia, northern Ecuador, western Venezuela and eastern Panamá. Tectonic reconstructions based upon characterization of more than thirty litho-tectonic and morpho-structural units, terrane assemblages and tectonic realms, and their bounding suture and fault systems, highlight the intimate and complementary Mesozoic-Cenozoic history of the Northern Andean Block and the Pacific and Caribbean Plates. The complex nature of Northern Andean assembly contrasts with ‘‘classical’’ Central Andean ‘‘Cordilleran-type’’ orogenic models. Differences render the application of typical Cordilleran-type models inappropriate for the Colombian Andes. The importance of underlying Proterozoic through mid-Mesozoic elements, in the development of Meso-Cenozoic Northern Andean orogeny-phase tectonic configurations is analyzed in the light of spatial-temporal studies and reconstructions related to basin formation, sedimentation, deformation, uplift mechanisms, structural style and magmatic evolution. The pre-Andean architecture of north western South America has played a pre-determinative role in the development of the Northern Andean orogenic system. 16 contributions analyze key stratigraphic, structural, metamorphic, magmatic and tectonic questions, and provide solutions as far as the most recent published field-based studies permit. The volume provides geological interpretations and tectonic models which contrast with repetitive theoretical proposals frequently found in the available literature.

The fish faunas of continental South and Central America constitute one of the greatest concentrations of aquatic diversity on Earth, consisting of about 10 percent of all living vertebrate species. Historical Biogeography of Neotropical Freshwater Fishes explores the evolutionary origins of this unique ecosystem. The chapters address central themes in the study of tropical biodiversity: why is the Amazon basin home to so many distinct evolutionary lineages? What roles do ecological specialization, speciation, and extinction play in the formation of regional assemblages? How do dispersal barriers contribute to isolation and diversification? Focusing on whole faunas rather than individual taxonomic groups, this volume shows that the area’s high regional diversity is not the result of recent diversification in lowland tropical rainforests. Rather, it is the product of species accumulating over tens of millions of years and across a continental arena.

This book summarizes the exploration history and provides a framework for assessing the economic potential of the country’s minerals by defining minimal deposit parameters for the various commodities present. Suriname was explored extensively for mineral occurrences in the course of the previous century, indicating the presence of a range of commodities. The country mined and processed bauxite for a century (until 2016), and has an even longer history of small-scale alluvial gold mining; it is currently home to two major gold producers. However, exploration activities have been limited during the past 4 decades as most parts of Suriname’s interior are difficult to access, making geological fieldwork both difficult and expensive. Further, the markets and prices have changed in the interim, which calls for a fresh look at the historic data.