TY  - JOUR
A1  - Vasquez, Mónica
A1  - Altenberger, Uwe
A1  - Romer, Rolf L.
A1  - Sudo, Masafumi
A1  - Moreno-Murillo, Juan Manuel
T1  - Magmatic evolution of the Andean Eastern Cordillera of Colombia during the Cretaceous : Influence of previous tectonic processes
N2  - The Eastern Cordillera of the Colombian Andes represents an inverted Cretaceous basin where Cretaceous magmatism is characterized by rare mafic dykes and sills. We use Ar-40/Ar-39, Sr-Nd-Pb isotopes, as well as major and trace elements analyses of Cretaceous intrusions from both flanks of the Eastern Cordillera in combination with structural data to document the complex evolution of the basin. Magmatism, which is diachronous and geochemically diverse, seems to be related to mantle melting beneath the most subsiding segments of each sub-basin during enhanced extensional tectonics. The mafic intrusions display two different compositional series: an alkaline one with OIB-like pattern and a tholeiitic one with MORB-like features. This indicates at least two diverse mantle sources. Trace-element patterns suggest that the intrusions were emplaced in an extensional setting. Ar-40/Ar-39 dating on primary plagioclase and hornblende provides plateau ages between similar to 136 and similar to 74 Ma. The geochemical and temporal diversities show that the emplacement of the magmas was tectonically controlled, each sub-basin reflecting an individual subsidence event.
Y1  - 2010
UR  - http://www.sciencedirect.com/science/journal/08959811
U6  - https://doi.org/10.1016/j.jsames.2009.02.003
SN  - 0895-9811
ER  -