Title
The Central Atlantic Magmatic Province extends into Bolivia
Date Issued
01 February 2014
Access level
metadata only access
Resource Type
journal article
Author(s)
Université de Grenoble 1
Abstract
The Central Atlantic Magmatic Province (CAMP) is the largest continental flood basalt (CFB) province on Earth and was associated with the onset of fragmentation of the supercontinent Pangea at the Triassic-Jurassic boundary. In order to clarify the extent of the CAMP in South America, we investigate basaltic remnants in southern Bolivia (Tarabuco, Entre Ríos and Camiri areas) by combining stratigraphic, geochronological (40Ar/39Ar data) and geochemical (major and trace element, Nd-Sr isotopes) approaches. Lava-flows reaching a total thickness up to 150m and associated sills overlie syn-rift red beds assigned to the Triassic. The magmatic rocks consist of low-Ti tholeiites that are remarkably homogeneous in composition. Notably, their trace element and Nd-Sr isotopic compositions closely match those of CAMP basalts particularly those of southwest Brazil. 40Ar/39Ar dating failed to yield robust plateau ages but the best estimates of the crystallization age at 198.1±1.5 and 199.2±2.2Ma are similar to those of CAMP basalts throughout the province. These Bolivian basalts, which may have covered an initial surface of ~30,000km2, represent the known southernmost occurrence of the CAMP. They were erupted as a single pulse, more than 8000km away from the northern edge of the province. We discuss the implications of such a huge elongated CFB for the current plume models and we suggest, as an alternative, that large-scale melting beneath the Pangea supercontinent due to mantle global warming could have triggered the emplacement of the CAMP. © 2013 Elsevier B.V.
Start page
33
End page
43
Volume
188
Language
English
OCDE Knowledge area
Geología
Subjects
Scopus EID
2-s2.0-84895013297
Source
Lithos
ISSN of the container
00244937
Sponsor(s)
We acknowledge P. Capiez for XRF analyses, R. Carampin for electron microprobe analyses, C. Douchet for ICP-MS analyses and C. Bassin for isotopes analyses. Support from the Institut de Recherche pour le Développement (IRD) for field work is gratefully acknowledged. We are grateful to M. Ducea for his constructive review and to D. Baker and A.C. Kerr for their editorial handling.
Sources of information:
Directorio de Producción Científica
Scopus