Relationship of Mesozoic graben development, stress, shortening magnitude, and structural style in the Eastern Cordillera of the Colombian Andes

2013 ◽  
Vol 377 (1) ◽  
pp. 257-283 ◽  
Author(s):  
E. Tesón ◽  
A. Mora ◽  
A. Silva ◽  
J. Namson ◽  
A. Teixell ◽  
...  
Keyword(s):  
Eastern Cordillera ◽  
Colombian Andes ◽  
Structural Style ◽  
Relationship Of

The influence of backstop geometry in the structural style of the Eastern Cordillera of Colombia: A sandbox modeling approach 

2021 ◽  
Author(s):  
Camilo Andrés Conde Carvajal ◽  
Cristhian Bolívar Riascos Rodríguez ◽  
Michael Andres Avila Paez ◽  
Andreas Kammer
Keyword(s):  
Kink Band ◽  
Ductile Deformation ◽  
High Plains ◽  
Angle Of Internal Friction ◽  
Eastern Cordillera ◽  
Surface Uplift ◽  
Structural Style ◽  
Mountain System ◽  
Mountain Front ◽  
Structural Relief

<p>Among the foreland belts of the Andean mountain system, the Eastern Cordillera of Colombia (EC) represents a unique example of an isolated, bi-vergent mountain belt. In contrast, to block tectonics of broken foreland basins, it displays a ductile deformation style which involves two mountain fronts with a structural relief of the order of 10 km. Internal parts of the EC have been shortened by buckling at high and a homogeneously strained basement at deeper structural levels. These deformation patterns likely attest to conditions of a thermally weakened backarc setting. Two opposed scenarios have been postulated for its surface uplift and consequent exhumation: 1) an E-migrating deformation front and the formation of progressively forward breaking faults; and 2) the pop-up of a weak crustal welt enclosed by strong foreland blocks. In this latter setting, a synchronous early formation of marginal mountain fronts and a late-stage surface uplift of a central domain may be anticipated. These two constellations compare, in terms of a contrasting model setup, to a foreland migrating orogenic wedge or a relatively stable, doubly vergent wedge formed above a structural discontinuity or rheologic boundaries that acted as sites for the nucleation of the marginal faults.</p><p>In this contribution, we opt to examine the “boundary” conditions for the development of a doubly vergent wedge formed at the tip line of a rigid tapering backstop, that simulates a rigid foreland block. With respect to the shape of this backstop, we examine the effects of tip angles less than the angle of internal friction (<30°) and find, that at a low tip angle of 10° the pop-up evolves above a forward-breaking principal kink-band with the synchronous formation of a sequence of conjugate back-kinks that cut into the sand pack, as it is pushed toward the backstop. At a moderate tip angle of 20<sup>o </sup>the forward-breaking kink-band is slightly steeper than the backstop and gives rise to a frontal fold with an overturned limb. This latter geometrical configuration loosely compares to the structural relations of a structural section through the high plains of Bogotá, where the eastern mountain front defines a strongly deformed antiform, that is juxtaposed against an undeformed margin of the adjacent Guyana shield.</p>

Passiflora splendida and P. quinonesiae, two new species of Passiflora supersection Tacsonia (Passifloraceae) from the Colombian Andes

Phytotaxa ◽  
2016 ◽  
Vol 268 (3) ◽  
pp. 181
Author(s):  
MIGUEL MACGAYVER BONILLA MORALES ◽  
ADRIANA CAROLINA AGUIRRE-MORALES ◽  
CREUCÍ MARÍA CAETANO
Keyword(s):  
New Species ◽  
Conservation Status ◽  
Stem Size ◽  
Eastern Cordillera ◽  
Floral Tube ◽  
Taxonomic Key ◽  
The Andes ◽  
Colombian Andes ◽  
Two New Species

Two new species, Passiflora splendida and P. quinonesiae of the section Colombiana from the Andes of Cundinamarca Department (Colombia Eastern Cordillera) are described and illustrated. Passiflora splendida is morphologically similar to P. cremastantha of the series Leptomischae, but can be distinguished by its linear stipules, petioles up to 1.8 cm long, lance-ovate leaves (6–8.5 × 2.5–3.3 cm), flowers with a diameter of 9–11 cm long, sepals and petals with intermediate disposition, both longer than the floral tube, floral tube of 3.2–4.5 cm long and fusiform ovary. Passiflora quinonesiae is similar to the species of series Colombianae, most closely related to P. cuatrecasasii and P. lanata. It differs from P. cuatrecasasii by its terete stem, size of the leaves 4.4–15 × 10.3 cm, elliptic bracts and floral tube 5.2–6 cm long. It differs from P. lanata by its ovate leaves, bracts halfway down the floral tube, elliptical sepals and petals, and elliptical ovary. In addition, a taxonomic key to section Colombiana ser. Colombianae and Leptomischae for Colombia is included and information about the ecology, distribution, and conservation status of P. splendida and P. quinonesiae are discussed.

scholarly journals Gene flow and Andean uplift shape the diversification of Gasteracantha cancriformis (Araneae: Araneidae) in Northern South America

2018 ◽  
Author(s):  
Fabian C. Salgado-Roa ◽  
Carolina Pardo-Diaz ◽  
Eloisa Lasso De Paulis ◽  
Carlos F. Arias ◽  
Vera Nisaka Solferini ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Gene Flow ◽  
South America ◽  
Color Polymorphism ◽  
Early Pleistocene ◽  
Eastern Cordillera ◽  
Colombian Andes ◽  
The Face ◽  
Andean Uplift ◽  
Northern South America

ABSTRACTAimThe Andean uplift has played a major role shaping the current Neotropical biodiversity. However, in arthropods other than butterflies, little is known about how this geographic barrier has impacted species historical diversification. Here we examined the phylogeography of the widespread and color polymorphic spider Gasteracantha cancriformis to: (i) evaluate the effect of the northern Andean uplift on its divergence and, (ii) assess whether its diversification occurred in the presence of gene flow.LocationNorthern Andes and BrazilMethodsWe inferred phylogenetic relationships and divergence times in G. cancriformis using mitochondrial and nuclear data from 105 individuals in northern South America. Genetic diversity, divergence and population structure were quantified. We also compared multiple demographic scenarios for this species using a model-based approach (PHRAPL) to establish divergence with or without gene flow. Finally, we evaluated the association between genetic variation and color polymorphism.ResultsBoth nuclear and mitochondrial data supported two well-differentiated clades, which correspond to populations occurring in opposite sides of the Eastern cordillera of the Colombian Andes. The splitting between these clades occurred in the early Pleistocene, around 2.13 million years ago (95% HPD = 0.98–3.93).Despite this vicariant event, there is shared genetic variation between the clades, which is better explained by a scenario of historical divergence in the face of gene flow. Color polymorphism was randomly scattered in both clades and is not statistically associated with the genetic variation studied here.Main ConclusionsThe final uplift of Eastern cordillera of the Colombian Andes was identified as the major force that shaped the diversification of G. cancriformis in Northern South America, resulting in a cis- and trans-Andean phylogeographic structure for the species. The divergence in the face of gene flow between cis- and trans-Andean populations found for this spider has been likely facilitated by the presence of low-elevation passes across the Eastern Colombian cordillera. Our work constitutes the first example where the Andean uplift coupled with gene flow influenced the evolutionary history of an arachnid lineage.

scholarly journals Influence of salt in the tectonic development of the frontal thrust belt of the eastern Cordillera (Guatiquía area, Colombian Andes)

2015 ◽  
Vol 3 (4) ◽  
pp. SAA17-SAA27 ◽  
Author(s):  
Vanessa Parravano ◽  
Antonio Teixell ◽  
Andrés Mora
Keyword(s):  
Structural Model ◽  
Salt Tectonics ◽  
Thrust Belt ◽  
Eastern Cordillera ◽  
Salt Migration ◽  
Colombian Andes ◽  
Kinematic Evolution ◽  
Geologic Maps ◽  
History Of ◽  
Tectonic Development

Geologic maps, seismic lines, and data from a dry exploration well were used to develop a new structural model for a segment of the eastern foothills of the Eastern Cordillera of Colombia, emphasizing the role of salt tectonics. Milestones in the deformation history of the Guatiquía foothills were studied by sequential section restoration to selected steps. Uncommon structural geometries and sparse salt occurrences were interpreted in terms of a kinematic evolution in which Cretaceous salt migration in extension produced a diapiric salt wall, which was subsequently welded during the main episodes of the Andean compression, when the salt wall was squeezed generating a large overturned flap. Salt-weld strain hardening resulted in breakthrough thrusting across the overturned flap in late deformation stages. We have evaluated a pattern of salt tectonics previously unrecognized in the foothills thrust belt, which may be significant in other parts of the external Colombian Andes.

scholarly journals Structural Style and Kinematic History of the Colombian Eastern Cordillera

2021 ◽  
Vol 9 ◽  
Author(s):  
Diego Costantino ◽  
Douglas Paton ◽  
Andrés Mora
Keyword(s):  
Cross Sections ◽  
Evolutionary Model ◽  
Convergent Margins ◽  
Significant Information ◽  
Growth Strata ◽  
Eastern Cordillera ◽  
Regional Deformation ◽  
Structural Style ◽  
History Of ◽  
Shortening Rate

Fold-and-thrust belts and their associated structures are among the most common geological features of convergent margins. They provide significant information about crustal shortening and mountain-building processes. In subaerial belts, where the erosional rates are high and the growth strata are mostly eroded, methodologies such as that presented here can provide insights into to their formation. Two 2D cross-sections located in the Eastern Cordillera of Colombia are presented in this research. These sections extend from the Bogota Savanna to The Llanos, parallel to the regional deformation direction. Section construction was carried out using commercial surface data, and seismic information provided by Ecopetrol. Published thermochronometric data, gravel-clast petrography analysis, and paleoflora analysis were used to construct a viable tectono-evolutionary history of the study area. This evolutionary model is presented here in two palinpastic restorations from the Early Paleogene to Recent (∼65 Ma to Present-day). Section 1 and Section 10 accumulated 17.3 km and 19.5 km of shortening, respectively. The section reconstruction displays two major tectonic events – post-rift subsidence during the Early-Mid Paleogene, and positive inversion from the Oligocene to Recent (∼33 Ma to Present-day). This investigation focuses on the compressional period, where the structural analysis evidences an acceleration in the shortening rate, as well as a progressive migration of the deformation from northwest to southeast. This research discusses the extent and limitation of this methodology, as well as the principal structural aspects of the reconstruction.

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