New SHRIMP U-Pb data from the Famatina Complex : constraining Early-Mid Ordovician Famatinian magmatism in the Sierras Pampeanas, Argentina
Dahlquist, J.A.; Pankhurst, Robert; Rapela, C.W.; Galindo, C.; Alasino, P.; Fanning, C.M.; Saavedra, J.; Baldo, E.. 2008 New SHRIMP U-Pb data from the Famatina Complex : constraining Early-Mid Ordovician Famatinian magmatism in the Sierras Pampeanas, Argentina. Geologica acta : an international earth science journal, 6 (4). 319-333. 10.1344/105.000000260Before downloading, please read NORA policies.
New SHRIMP U-Pb zircon ages are reported for igneous and sedimentary rocks of the Famatina Complex, constraining the age of the magmatism and the ensialic basins. Together with whole-rock and isotope geochemistry for the igneous rocks from the complex, these ages indicate that the voluminous parental magmas of metaluminous composition were derived by partial melting of an older lithosphere without significant asthenospheric contribution. This magmatism was initiated in the Early Ordovician (481 Ma). During the Mid-Late Ordovician, the magmatism ceased (463 Ma), resulting in a short-lived (no more than ~20 Ma) and relatively narrow (~100-150 km) magmatic belt, in contrast to the long-lived cordilleran magmatism of the Andes. The exhumation rate of the Famatina Complex was considerably high and the erosional stripping and deposition of Ordovician sediments occurred soon after of the emplacement of the igneous source rocks during the Early to mid-Ordovician. During the upper Mid Ordovician the clastic contribution was mainly derived from plutonic rocks. Magmatism was completely extinguished in the Mid Ordovician and the sedimentary basins closed in the early Late Ordovician.
|Programmes:||BGS Programmes 2008 > International Business Development|
|Additional Information:||Geologica acta is an OPEN ACCESS international journal that aims to stimulate rapid diffusion of results and efficient exchange of ideas between the widespread communities of Earth Science researchers (with special emphasis on Latinamerica, The Caribbean, Europe, the Mediterranean).|
|Additional Keywords:||Argentina, Magmatism, Ordovician|
|NORA Subject Terms:||Earth Sciences|
|Date made live:||12 Mar 2009 11:06|
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