High quality U-Pb (ID-TIMS) baddeleyite ages define the timing of crystallization of the Rincón del Tigre layered intrusion (1110 ± 2 Ma) and the Huanchaca mafic suite (1112 ± 2 Ma) in the Bolivian Precambrian shield - SW portion of the Amazonian Craton. The identical ca. 1110-1112. Ma ages obtained for each (about 500 km apart) suggest these belong to a previously unrecognized LIP. The large area of distribution and the intraplate geochemistry for the 1110 Ma Huanchaca-Rincón del Tigre rocks support a relationship with mantle plume activity pre-dating Rodinia breakup. Contemporary anorogenic magmatism in Amazonia is probably linked to crustal melting caused by the LIP. The newly identified 1110 Ma LIP has a tight age match with intraplate magmatism in the Congo, Kalahari and Indian cratons, and the Keweenawan event of central Laurentia among others. While a reconstruction history of Amazonia and Laurentia is still a matter of debate on paleomagnetic grounds, a reconstruction link with other crustal blocks remains possible.
Bibliographical noteFunding Information:
The first author thanks the Brazilian National Research Council (CNPq) for its continuous support for the research projects. This is publication no. 36 of “The Large Igneous Provinces – Continental Reconstruction – Metallogeny, Industry Consortium Project ( www.supercontinent.org )”. Finally the authors are grateful to the reviewers and the Editor-in-Chief for offering constructive comments and improvements in the early version of the manuscript.
© 2014 Elsevier B.V.
- Amazonian Craton
- Mafic-ultramafic intrusions
- U-Pb baddeleyite ages