Geochemistry and geochronology from Cretaceous magmatic and sedimentary rocks at 6°35′ N, western flank of the Central cordillera (Colombian Andes): Magmatic record of arc growth and collision. (July 2017)

• Record Type: Journal Article
• Authors: Jaramillo, J.S.; Cardona, A.; León, S.; Valencia, V.; Vinasco, C.
• Is Part Of: Journal of South American earth sciences. Volume 76(2017:Jul.)
• Page Start: 460
• Page End: 481
• Publication Date: 2017-07
• Subjects: Northern Andes -- Cretaceous -- Arc magmatism -- Collision -- U-Pb LAICP-MS -- Geochemistry -- Colombia; Geology -- Latin America -- Periodicals; Earth sciences -- Latin America -- Periodicals; Geology -- Antarctica -- Periodicals; Earth sciences -- Antarctica -- Periodicals; Geology -- Caribbean Area -- Periodicals; Earth sciences -- Caribbean Area -- Periodicals; Géologie -- Amérique latine -- Périodiques; Sciences de la terre -- Amérique latine -- Périodiques; Géologie -- Antarctique -- Périodiques; Sciences de la terre -- Antarctique -- Périodiques; Géologie -- Caraïbes (Région) -- Périodiques; Sciences de la terre -- Caraïbes (Région) -- Périodiques; Earth sciences; Geology; Antarctica; Caribbean Area; Latin America; Periodicals; 550.5
• DOI: 10.1016/j.jsames.2017.04.012
• Languages: English
• ISSNs: 0895-9811

Abstract

Abstract: The spatio-temporal, compositional and deformational record of magmatic arcs are sensible markers of the long-term evolution of convergent margins including collisional events. In this contribution, field relations, U-Pb LA-ICP-MS zircon geochronology from magmatic and sedimentary rocks, and whole-rock geochemistry from volcanic and plutonic rocks are used to reconstruct the Cretaceous arc growth and collision in the awakening of the Northern Andean orogeny in northwestern Colombia. The Quebradagrande Complex that includes a sequence of volcanic rocks intercalated with quartz-rich sediments is a tholeiitic arc characterized by an enrichment in LREE and Nb-Ti anomalies that document crustal thickening in an arc system that was already active by ca. 93 Ma. This arc was built associated with thin continental and newly formed oceanic crust, as suggested by the presence of Triassic and older detrital zircons in the associated sandstones. This fringing arc subsequently experienced deformation and a major switch to and enriched calc-alkaline high-k plutonism between 70 and 73 Ma. The deformation record and changes in composition are related to an opposite double-vergence Molucca-sea type arc-arc collision that ended with the accretion to the continental margin of an allochthonous island arc built on an oceanic plateau associated with the Caribbean plate. The new time-framework suggest that the Late Cretaceous to Paleocene collisional tectonics include various stages before the switching to a subduction-dominated regime in most of the Cenozoic. Highlights: The Quebradagrande Complex is a Cretaceous continental fringing arc. Tholeitic arc magmatism formed in thin crust. Late Cretaceous high-k plutonism associated to late-collisional tectonics. Various Cretaceous magmatic arcs were juxtaposed in northern South America. The Late Cretaceous to Paleocene orogeny in the northern Andes include various collisional phases.