Vertical tectonics at a continental crust‐oceanic plateau plate boundary zone: Fission track thermochronology of the Sierra Nevada de Santa Marta, Colombia

Abstract

The topographically prominent Sierra Nevada de Santa Marta forms part of a faulted block of continental crust located along the northern boundary of the South American Plate, hosts the highest elevation in the world (∼5.75 km) whose local base is at sea level, and juxtaposes oceanic plateau rocks of the Caribbean Plate. Quantification of the amount and timing of exhumation constrains interpretations of the history of the plate boundary, and the driving forces of rock uplift along the active margin. The Sierra Nevada Province of the southernmost Sierra Nevada de Santa Marta exhumed at elevated rates (≥0.2 Km/My) during 65–58 Ma in response to the collision of the Caribbean Plateau with northwestern South America. A second pulse of exhumation (≥0.32 Km/My) during 50–40 Ma was driven by underthrusting of the Caribbean Plate beneath northern South America. Subsequent exhumation at 40–25 Ma (≥0.15 Km/My) is recorded proximal to the Santa Marta-Bucaramanga Fault. More northerly regions of the Sierra Nevada Province exhumed rapidly during 26–29 Ma (∼0.7 Km/My). Further northward, the Santa Marta Province exhumed at elevated rates during 30–25 Ma and 25–16 Ma. The highest exhumation rates within the Sierra Nevada de Santa Marta progressed toward the northwest via the propagation of NW verging thrusts. Exhumation is not recorded after ∼16 Ma, which is unexpected given the high elevation and high erosive power of the climate, implying that rock and surface uplift that gave rise to the current topography was very recent (i.e., ≤1 Ma?), and there has been insufficient time to expose the fossil apatite partial annealing zone

Hyperspectral imaging for the determination of bitumen content in Athabasca oil sands core samples

“…For instance, Villagómez et al (2011a) documented in the Central Cordillera the same Late Cretaceous to Paleocene deformation events that have been documented by Parra et al (2012) and Caballero et al (2013a, b) in the Magdalena Valley. In addition, the events proposed by Villagómez et al (2011b) for the Eocene and later, in general, coincide with our data. The correlation between the late Oligocene peak orogenic advance and the onset of Panama collision with South America is even more conspicuous (Ketcham, 2005), of one Paleocene sample in the Lisama Formation displaying possible onset of exhumation since late Eocene to early Oligocene.…”

Linking Late Cretaceous to Eocene Tectonostratigraphy of the San Jacinto Fold Belt of NW Colombia With Caribbean Plateau Collision and Flat Subduction

“…Paleotectonic reconstructions (Pindell & Kennan, ; Spikings et al, ) suggest that at this time, the Caribbean Plate moved toward the NE relative to the North and South American Plates and started to occupy space between them. Villagómez, Spikings, Mora, et al () and Caballero, Parra, et al () used apatite fission track thermochronology to identify an exhumation pulse in the San Lucas ridge and southernmost SNSM during early Paleocene times (Figure ), which they relate to the collision of the Caribbean Plateau with northwestern South America. We consider that the absence of lower Paleocene deposits in northwestern Colombia (planktonic zones P.0 to P.2., 65 to 61 Ma) and the unconformity that has been reported in outcrops between Sequence 1 (Cansona) and Sequence 2 (San Cayetano, Figure ) are the expression of a regional shortening event, which took place in latest Cretaceous to early Paleocene times and which would be related to the collision of the Caribbean Plateau.…”

“…Using apatite (U‐Th)/He thermochronology, Restrepo et al () and Villagómez, Spikings, Mora, et al () identified middle Eocene exhumation pulses in the northern CC (Antioqueño Plateau) and in the southern SNSM. However, while Restrepo et al () related the middle Eocene exhumation of the northern CC to a change in the rate of convergence between Nazca (Farallon) and South America, Villagómez, Spikings, Mora, et al () relate it to underthrusting of the Caribbean Plate beneath northern South America. Paleotectonic reconstructions (Boschman et al, ; Kroehler et al, ; Matthews et al, ; Müller et al, ; Pindell & Kennan, ; Ross & Scotese, ) show that between 56 and 45 Ma there was a major readjustment in the configuration of the South American, Caribbean, and North American Plates (Figure ).…”

Spatial and temporal uplift history of South America from calibrated drainage analysis

“…[]; Villagómez et al . []; Michalak et al . [] for the Northern Andes; selected references from compilation in Barnes and Ehlers [] for Central Andes; Thomson et al .…”