Geology and Tectonics of Northwestern South America The Pacific-Cari
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 magnet
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Fabio Cediel Robert Peter Shaw Editors
Geology and Tectonics of Northwestern South America The Pacific-Caribbean-Andean Junction
Frontiers in Earth Sciences Series editors J.P. Brun, Clermont-Ferrand, France Onno Oncken, Potsdam, Germany Helmut Weissert, Zürich, Switzerland Wolf-Christian Dullo, Kiel, Germany
More information about this series at http://www.springer.com/series/7066
Central Macarena seen from the east. Based upon early field studies within the Macarena range and the Roraima tepuis, Augusto Gansser documented the puzzling relationships between the Guiana Shield and the Andean belt, in the process formulating the “Roraima Problem” from a geomorphologic-stratigraphic standpoint. Subsequent studies served to highlight the “problem” within the Macarena uplift, where Cambrian sediments are exposed at approx. 1000 m above sea level whilst Silurian sediments within the Orinoco low are buried at approx. 2300 m depth. The coexistence of vertical tectonics (over 2000 m displacement) and extensional strain systems (Phanerozoic graben-rift fills), with thrust-and-fold belts, may point to concealed wrench structures in subsurface, undetected by geophysical methods. An updated synthesis of the Roraima Problem, using new surface and sub-surface cartographic and structural data, is presented within Chap. 1 of this volume. Redrawn from Gansser A., 1941, Central Macarena, Geological Report Shell No. 100, Appendix 12-16 with enclosures.
Geological landscape of the Rio Nevado canyon. The juncture between the Santander Massif and the Eastern Cordillera presents some of the most complex structural and stratigraphic relationships to be found anywhere in the Colombian Andes. This scaled geologic sketch of the Rio Nevado canyon was generated during detailed field-based mapping and structural and stratigraphic study, which produced over 20 km of 1:25.000-scale structural cross sections, as revealed in Chap. 9 of this volume. The composition highlights intensely disharmonic folds outcropping along the southern and northern walls of the Rio Nevado canyon, whilst maintaining the relative orientation and geometry of the structures and permitting comparison of the fold styles in both canyon walls. Completed in the style of pioneering Swiss geologist, Arnold Heim, this sketch provides a reliable graphical representation of the complex architecture underlying the Eastern Cordillera. Its production harkens a return to classical methodologies in the understanding and interpretation of natural landscape evolution vs. the indiscriminate use of purely algorithmic methods in the reconstruction of “balanced cross sections”. Adapted from original illustration in ink and water colour on parchment by Laura Román García.
Fabio Cediel • Robert Peter Shaw Editors
Geology and Tectonics of Northwestern South America The Pacific-Caribbean-Andean Junction
Editors Fabio Cediel Consulting Geologist Department of Geology University EAFIT Medellín, Colombia
Robert Peter Shaw Consulting Geologist Kelowna, BC, Canada
ISSN 1863-4621
