Neoproterozoic to Jurassic tectono-metamorphic events in the Sierra Nevada de Santa Marta Massif, Colombia: insights from zircon U-Pb geochronology and trace element geochemistry

ABSTRACT

The Sierra Nevada de Santa Marta Massif (SNSM) in the Northern Andes affords an insight into lower crustal section structural relations. This polymetamorphic basement comprises high-grade gneisses, which alternate with imbricate slivers of medium-to high-grade schists. New field observations coupled with LA-ICP-MS U-Pb zircon geochronology and trace element geochemistry reveal some hallmarks on the evolution of this strongly remobilized crustal section. The Proterozoic Rodinia-type basement (1100 − 880 Ma) recorded at least two separated tectono-metamorphic events (M₀ and M₁) and was subsequently affected by a magmatic episode during the Ordovician (~450 Ma; M₂). During the Permian, subduction of Panthalassian oceanic crust beneath Pangaea led to the installation of a magmatic-arc and probably coeval metamorphism (~288-266 Ma; M₃). Middle-Late Triassic roll-back extension of the upper plate led to anatexis and metamorphism (M₄) reaching peak conditions at ca. 239 Ma with concurrent crystallization of garnet and sillimanite, followed by a decreasing geothermal gradient at ca. 202 Ma. Early Jurassic arc build-up under a rejuvenated convergence was contemporaneous to metamorphism on an accretionary wedge (M₅) at ca. 185 Ma. The SNSM Massif basement units yield metamorphic ages that compare to similar tectono-metamorphic provinces in NW-Gondwana, including the Central Cordillera of Colombia, the Guajira Peninsula, the Mérida Andes, the Perijá Range, the Santander Massif, and the Central American and Mexican terranes to the south of the Ouachita-Marathon Suture (Oaxaquia, Mixteca, and Maya blocks). Age equivalence of these events is best explained by the existence of a conjugate margin with Laurentia until the Late Triassic ~216 Ma, which preceded the inception of a Colombian marginal seaway during the break-up of western Pangaea. Furthermore, the presence of Ordovician metamorphic rocks in the SNSM Massif confirms the extent of a Famatinian arc along NW-Gondwana during the Early Palaeozoic.

GRAPHICAL ABSTRACT

KEYWORDS:

• Santa Marta Massif
• geochronology
• Peri-Gondwana terranes
• amphibolite facies metamorphism
• Pangaea

Acknowledgments

The authors want to thank the International Geology Review editors and reviewers for their constructive comments, which significantly improved this paper. COLCIENCIAS financially supported this work in the framework of the project “Evolución Tectónica del Margen Caribeño Colombiano,” also supported by a Bonus Qualité Recherche (BQR) Sud grant from ISTerre, Université Grenoble Alpes. Marcel Guillong carefully explained geochronological U-Pb data reduction procedures. Alejandro Beltrán shared his knowledge on U-Pb sample preparation. We acknowledge the Universidad Nacional de Colombia students and professors during the 2013– and 2014 field trips, who explored the Sierra Nevada de Santa Marta. Finally, the principal author wants to dedicate this work to the Sierra Nevada de Santa Marta inhabitants, the Kogui, Arhuaco, Kankuamo, and Wiva communities, and the memory of a researcher and friend, Juan Sebastían Díaz.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article and its supplementary materials.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This work was supported by the Communauté Université Grenoble Alpes [Institut des Sciences de la Terre, Bonus Qualité Recherche Sud grant]; Departamento Administrativo de Ciencia, Tecnologia e Innovación (COLCIENCIAS) [Doctorados Nacionales no 567 de 2012, No. 660-2014 - and Tectonic evolution of the Colombian Caribean margin Grant number 110152128724].