Geochronological, geochemical and isotopic characterisation of the basement of the Chocó-Panamá Block in Colombia

The Chocó-Panamá block is the land bridge that connects Central and South America forms trailing edge of Caribbean Large Igneous Province (CLIP). New field observations are combined with new geochemical, isotopic 40Ar/39Ar analyses mafic basement Chocó within Colombia. These integrated U/Pb ages detrital zircons extracted from siliciclastic carbonate rocks unconformably overlie basement. data used to constrain age, tectonic origin evolution Block, which improve models Plate. whole-rock chemical compositions lavas suggests they formed an oceanic plateau, extremely similar plateau units in Colombia, Ecuador, Panamá Costa Rica. (groundmass) dates affected by early calcic late potassic alteration, none accurate measurements time crystallisation. A comparison 40Ar(radiogenic), 39Ar(K) 37Ar(Ca) reveals at least three argon reservoirs groundmass, where two a consequence alteration. Our most albeit imprecise estimate crystallisation age ≥86.0 ± 6.3 Ma, date groundmass aliquot contains lowest proportion secondary Ar reservoirs. This consistent few reliable obtained for CLIP. concordia maximum depositional overlying sedimentary ~28 supporting previous conclusions collided during Oligocene Early Miocene. Detrital Precambrian – Triassic older cover sequences not present younger due surface uplift Serranía del Baudó, presumably collisional tectonics.