1. Timing and rates of morpho-tectonic events in a segment of the Central and Western cordilleras of Colombia revealed through low-temperature thermochronology.
- Author
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Duque-Palacio, S., Seward, D., Restrepo-Moreno, S.A., and García-Ramos, D.
- Subjects
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ALUMINUM analysis , *ABSOLUTE value , *TECTONIC exhumation , *APATITE , *ZIRCON , *HORNBLENDE - Abstract
New zircon and apatite fission-track analyses and aluminium in hornblende thermobarometric data are presented from Cretaceous and Triassic plutons situated along an east-west transect across the Central Cordillera, the Cauca Romeral Fault System and the eastern slopes of the Western Cordillera in the Colombian Andes. The results are combined with published apatite (U–Th)/He ages revealing three episodes of increased cooling during the Late Cretaceous (~110 - 90 Ma), the Eocene (~55-40 Ma) and the Miocene (23-20 Ma). The latter two phases correlate well with the Pre-Andean and Proto-Andean periods previously identified on the basis of stratigraphic unconformities and thermochronology studies in the region. A fourth event, at ~10 Ma, is tentatively recognized in modelled data sets, but not by absolute age values. The thermochronology data imply a total of uplift-driven exhumation (i.e., crustal unroofing) in the study area of up to 10 kms since ~50 Ma at rates of ~0.1 km/Myr and 4 kms since ~23 Ma initially at 0.2 km/Myr. From 10 Ma the rates changed to 0.3–0.33 km/Myr with estimated geothermal gradients of 25–30 °C/km. Thermobarometry data suggest that the crystallization of the Cretaceous intrusions, now at the surface, took place at depths of 8–13 km confirming the amount of exhumation revealed by low-temperature thermochronology. • New thermochronology ages for Northern Andes combining apatite and zircon FT. • Thermochronology/thermobarometry dataset in the Northern Andes of Colombia. • Vertical profile shows pulses of uplift exhumation at ~110–90, 45–50 and 23 Ma. • Orogenic events involving erosional cooling and crustal unroofing from ~8 to 13 km. • Orogenic events are coeval with pulses in the Caribbean, Southern-Central Andes. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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