Diagnostic structural features of NW South America: Structural cross sections based upon detailed field transects

Abstract

This chapter illustrates the structural architecture of the Colombian Andes, highlighting the geometric and temporal relationships between lithologic units, faulting, and folding, as derived from field transects across key areas of the complex Colombian Cordilleran system. The summary presented herein, permits a better understanding of the tectonic, physiographic evolution and temporal genetic linkages within the Northern Andes. It is primarily a visual tool, intended to aid in the interpretation of segments of the Colombian Andes where insufficent geological data is available and hence, in the construction of structural models. The chapter consists of selected cross-sections constructed from actual field data and supported whether in seismic interpretation or well data. The field data was acquired during structural and stratigraphic surveys produced for the petroleum, coal and mineral industry, as well as for academic purposes. Most of the sections are balanced or at least admissible. The quality of the presented sections is supported on the coherence among detailed lithologic mapping, lateral facies changes, thickness variations of the lithostratigraphic units, and strict biostratigraphic control. Sections belonging to six regional transects are presented in the printed format. Whilst, an extended digital appendix includes 15 additional more specific structural case studies (Fig. 9.1). The following regional transects are portrayed in printed format: 1.Guajira Allochthon2.Maracaibo block3.Eastern Cordillera4.Central Cordillera5.Western Cordillera6.Chocó indenter The following detailed sections are appended in digital format: A1.Northern Eastern Cordillera, Chinácota Graben.A2.Northern Eastern Cordillera, Tamá Strike-slip tectonics.A3.Middle Magdalena Valley, La Salina-Infantas.A4.Eastern Cordillera, Central Sector.A5.Central Cordillera, Ibagué-Calarcá.A6.Western Cordillera, Bolívar Ultramafic Zoned Complex.A7.Upper Magdalena Valley, Ortega.A8.Upper Magdalena Valley, Pechúi.A9.Upper Magdalena Valley, San Antonio.A10.Eastern Cordillera, Western Foothills (Colombia, Huila).A11.Upper Magdalena Valley, Upar.A12.Upper Magdalena Valley, El Pensil-La Plata.A13.Upper Magdalena Valley, Iskana.A14.Putumayo, San Juan Norte.A15.Northern Eastern Cordillera - Rio Nevado Canyon.