TY  - JOUR
A1  - Zapata, Sebastian Henao
A1  - Cardona, A.
A1  - Jaramillo, J. S.
A1  - Patino, A.
A1  - Valencia, V.
A1  - Leon, S.
A1  - Mejia, D.
A1  - Pardo-Trujillo, A.
A1  - Castaneda, J. P.
T1  - Cretaceous extensional and compressional tectonics in the Northwestern Andes, prior to the collision with the Caribbean oceanic plateau
JF  - Gondwana research : international geoscience journal ; official journal of the International Association for Gondwana Research
N2  - The Cretaceous units exposed in the northwestern segment of the Colombian Andes preserve the record of extensional and compressional tectonics prior to the collision with Caribbean oceanic terranes. We integrated field, stratigraphic, sedimentary provenance, whole rock geochemistry, Nd isotopes and U-Pb zircon data to understand the Cretaceous tectonostratigraphic and magmatic record of the Colombian Andes. The results suggest that several sedimentary successions including the Abejorral Fm. were deposited on top of the continental basement in an Early Cretaceous backarc basin (150-100 Ma). Between 120 and 100 Ma, the appearance of basaltic and andesitic magmatism (similar to 115-100 Ma), basin deepening, and seafloor spreading were the result of advanced stages of backarc extension. A change to compressional tectonics took place during the Late Cretaceous (100-80 Ma). During this compressional phase, the extended blocks were reincorporated into the margin, closing the former Early Cretaceous backarc basin. Subsequently, a Late Cretaceous volcanic arc was built on the continental margin: as a result, the volcanic rocks of the Quebradagrande Complex were unconformably deposited on top of the faulted and folded rocks of the Abejorral Fm. Between the Late Cretaceous and the Paleocene (80-60 Ma), an arc-continent collision between the Caribbean oceanic plateau and the South-American continental margin deformed the rocks of the Quebradagrande Complex and shut-down the active volcanic arc. Our results suggest an Early Cretaceous extensional event followed by compressional tectonics prior to the collision with the Caribbean oceanic plateau. (C) 2019 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.
KW  - Northern Andes
KW  - Paleogeography
KW  - Cretaceous
KW  - Extension
KW  - Convergent margins
KW  - Provenance
Y1  - 2018
U6  - https://doi.org/10.1016/j.gr.2018.10.008
SN  - 1342-937X
SN  - 1878-0571
VL  - 66
SP  - 207
EP  - 226
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Weber, Marion
A1  - Cardona, A.
A1  - Valencia, V.
A1  - Altenberger, Uwe
A1  - Lopez-Martinez, M.
A1  - Tobon, M.
A1  - Zapata, Sebastian Henao
A1  - Zapata, G.
A1  - Concha, A. E.
T1  - Geochemistry and geochronology of the Guajira Eclogites, northern Colombia evidence of a metamorphosed primitive Cretaceous Caribbean Island-arc
JF  - Geologica acta
N2  - The chemical composition of eclogites, found as boulders in a Tertiary conglomerate from the Guajira Peninsula, Colombia suggests that these rocks are mainly metamorphosed basaltic andesites. They are depleted in LILE elements compared to MORB, have a negative Nb-anomaly and flat to enriched REE patterns, suggesting that their protoliths evolved in a subduction related tectonic setting. They show island-arc affinities and are similar to primitive island-arc rocks described in the Caribbean. The geochemical characteristics are comparable to low-grade greenschists from the nearby Etpana Terrane, which are interpreted as part of a Cretaceous intra-oceanic arc. These data support evidence that the eclogites and the Etpana terrane rocks formed from the same volcano-sedimentary sequence. Part of this sequence was accreted onto the margin and another was incorporated into the subduction channel and metamorphosed at eclogite facies conditions. Ar-40-Ar-39 ages of 79.2 +/- 1.1Ma and 82.2 +/- 2.5Ma determined on white micas, separated from two eclogite samples, are interpreted to be related to the cooling of the main metamorphic event. The formation of a common volcano-sedimentary protolith and subsequent metamorphism of these units record the ongoing Late Cretaceous continental subduction of the South American margin within the Caribbean intra-oceanic arc subduction zone. This gave way to an arc-continent collision between the Caribbean and the South American plates, where this sequence was exhumed after the Campanian.
KW  - Eclogites
KW  - Primitive island-arc
KW  - Geochronology
KW  - Guajira Peninsula
KW  - Colombia
KW  - Caribbean
Y1  - 2011
U6  - https://doi.org/10.1344/105.000001740
SN  - 1695-6133
VL  - 9
IS  - 3-4
SP  - 425
EP  - 443
PB  - Facultat de Geologia, Divisio III, Ciències Experimentals i Matemàtiques, Universitat de Barcelona
CY  - Barcelona
ER  -